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[v8,00/16] Introduce Nuvoton Arbel NPCM8XX BMC SoC

Message ID 20220711123519.217219-1-tmaimon77@gmail.com
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Series Introduce Nuvoton Arbel NPCM8XX BMC SoC | expand

Message

Tomer Maimon July 11, 2022, 12:35 p.m. UTC
This patchset  adds initial support for the Nuvoton 
Arbel NPCM8XX Board Management controller (BMC) SoC family. 

The Nuvoton Arbel NPCM8XX SoC is a fourth-generation BMC.
The NPCM8XX computing subsystem comprises a quadcore ARM 
Cortex A35 ARM-V8 architecture.

This patchset adds minimal architecture and drivers such as:
Clocksource, Clock, Reset, and WD.

Some of the Arbel NPCM8XX peripherals are based on Poleg NPCM7XX.

This patchset was tested on the Arbel NPCM8XX evaluation board.

Changes since version 7:
 - NPCM8XX clock driver
	- The clock and reset registers using the same memory region, 
	  due to it the clock driver should claim the ioremap directly 
	  without checking the memory region.

Changes since version 6:
 - NPCM reset driver
	- Modify warning message.
 - dt-bindings: serial: 8250: Add npcm845 compatible string patch accepted, due
   to it the patch removed from the patchset.

Changes since version 5:
 - NPCM8XX clock driver
	- Remove refclk if devm_of_clk_add_hw_provider function failed.
 - NPCM8XX clock source driver
	- Remove NPCM8XX TIMER_OF_DECLARE support, using the same as NPCM7XX.

Changes since version 4:
 - NPCM8XX clock driver
	- Use the same quote in the dt-binding file.

Changes since version 3:
 - NPCM8XX clock driver
	- Rename NPCM8xx clock dt-binding header file.
	- Remove unused structures.
	- Improve Handling the clocks registration.
 - NPCM reset driver
	- Add ref phandle to dt-binding.

Changes since version 2:
 - Remove NPCM8xx WDT compatible patch.
 - Remove NPCM8xx UART compatible patch.
 - NPCM8XX clock driver
	- Add debug new line.
	- Add 25M fixed rate clock.
	- Remove unused clocks and clock name from dt-binding.
 - NPCM reset driver
	- Revert to npcm7xx dt-binding.
	- Skip dt binding quotes.
	- Adding DTS backward compatibility.
	- Remove NPCM8xx binding include file.
	- Warp commit message.
- NPCM8XX device tree:
	- Remove unused clock nodes (used in the clock driver)
	- Modify gcr and rst node names.

Changes since version 1:
 - NPCM8XX clock driver
	- Modify dt-binding.
	- Remove unsed definition and include.
	- Include alphabetically.
	- Use clock devm.
 - NPCM reset driver
	- Modify dt-binding.
	- Modify syscon name.
	- Add syscon support to NPCM7XX dts reset node.
	- use data structure.
 - NPCM8XX device tree:
	- Modify evb compatible name.
	- Add NPCM7xx compatible.
	- Remove disable nodes from the EVB DTS.

Tomer Maimon (16):
  dt-bindings: timer: npcm: Add npcm845 compatible string
  dt-bindings: watchdog: npcm: Add npcm845 compatible string
  dt-binding: clk: npcm845: Add binding for Nuvoton NPCM8XX Clock
  clk: npcm8xx: add clock controller
  dt-bindings: reset: npcm: add GCR syscon property
  ARM: dts: nuvoton: add reset syscon property
  reset: npcm: using syscon instead of device data
  dt-bindings: reset: npcm: Add support for NPCM8XX
  reset: npcm: Add NPCM8XX support
  dt-bindings: arm: npcm: Add maintainer
  dt-bindings: arm: npcm: Add nuvoton,npcm845 compatible string
  dt-bindings: arm: npcm: Add nuvoton,npcm845 GCR compatible string
  arm64: npcm: Add support for Nuvoton NPCM8XX BMC SoC
  arm64: dts: nuvoton: Add initial NPCM8XX device tree
  arm64: dts: nuvoton: Add initial NPCM845 EVB device tree
  arm64: defconfig: Add Nuvoton NPCM family support

 .../devicetree/bindings/arm/npcm/npcm.yaml    |   7 +
 .../bindings/arm/npcm/nuvoton,gcr.yaml        |   2 +
 .../bindings/clock/nuvoton,npcm845-clk.yaml   |  49 ++
 .../bindings/reset/nuvoton,npcm750-reset.yaml |  10 +-
 .../bindings/timer/nuvoton,npcm7xx-timer.yaml |   2 +
 .../bindings/watchdog/nuvoton,npcm-wdt.txt    |   3 +-
 MAINTAINERS                                   |   2 +
 arch/arm/boot/dts/nuvoton-common-npcm7xx.dtsi |   1 +
 arch/arm64/Kconfig.platforms                  |  11 +
 arch/arm64/boot/dts/Makefile                  |   1 +
 arch/arm64/boot/dts/nuvoton/Makefile          |   2 +
 .../dts/nuvoton/nuvoton-common-npcm8xx.dtsi   | 170 +++++
 .../boot/dts/nuvoton/nuvoton-npcm845-evb.dts  |  30 +
 .../boot/dts/nuvoton/nuvoton-npcm845.dtsi     |  76 +++
 arch/arm64/configs/defconfig                  |   3 +
 drivers/clk/Kconfig                           |   6 +
 drivers/clk/Makefile                          |   1 +
 drivers/clk/clk-npcm8xx.c                     | 610 ++++++++++++++++++
 drivers/reset/reset-npcm.c                    | 207 +++++-
 .../dt-bindings/clock/nuvoton,npcm845-clk.h   |  49 ++
 20 files changed, 1206 insertions(+), 36 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/nuvoton,npcm845-clk.yaml
 create mode 100644 arch/arm64/boot/dts/nuvoton/Makefile
 create mode 100644 arch/arm64/boot/dts/nuvoton/nuvoton-common-npcm8xx.dtsi
 create mode 100644 arch/arm64/boot/dts/nuvoton/nuvoton-npcm845-evb.dts
 create mode 100644 arch/arm64/boot/dts/nuvoton/nuvoton-npcm845.dtsi
 create mode 100644 drivers/clk/clk-npcm8xx.c
 create mode 100644 include/dt-bindings/clock/nuvoton,npcm845-clk.h

Comments

Tomer Maimon July 12, 2022, 7:28 a.m. UTC | #1
Hi Stephen,

Thanks for your comments

On Mon, 11 Jul 2022 at 22:55, Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Tomer Maimon (2022-07-11 05:35:07)
> > Nuvoton Arbel BMC NPCM8XX contains an integrated clock controller which
> > generates and supplies clocks to all modules within the BMC.
> >
> > Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
> > ---
> >  drivers/clk/Kconfig       |   6 +
> >  drivers/clk/Makefile      |   1 +
> >  drivers/clk/clk-npcm8xx.c | 610 ++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 617 insertions(+)
> >  create mode 100644 drivers/clk/clk-npcm8xx.c
> >
> > diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> > index 48f8f4221e21..9aa915f6e233 100644
> > --- a/drivers/clk/Kconfig
> > +++ b/drivers/clk/Kconfig
> > @@ -428,6 +428,12 @@ config COMMON_CLK_K210
> >         help
> >           Support for the Canaan Kendryte K210 RISC-V SoC clocks.
> >
> > +config COMMON_CLK_NPCM8XX
> > +       tristate "Clock driver for the NPCM8XX SoC Family"
> > +       depends on ARCH_NPCM || COMPILE_TEST
> > +       help
> > +          This driver supports the clocks on the Nuvoton BMC NPCM8XX SoC Family.
>
> Please put this next to COMMON_CLK_NXP so that it is sort of sorted
> based on Kconfig symbol.
Will do
> > +
> >  source "drivers/clk/actions/Kconfig"
> >  source "drivers/clk/analogbits/Kconfig"
> >  source "drivers/clk/baikal-t1/Kconfig"
> > diff --git a/drivers/clk/clk-npcm8xx.c b/drivers/clk/clk-npcm8xx.c
> > new file mode 100644
> > index 000000000000..392f1fbba49b
> > --- /dev/null
> > +++ b/drivers/clk/clk-npcm8xx.c
> > @@ -0,0 +1,610 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Nuvoton NPCM8xx Clock Generator
> > + * All the clocks are initialized by the bootloader, so this driver allow only
> > + * reading of current settings directly from the hardware.
> > + *
> > + * Copyright (C) 2020 Nuvoton Technologies
> > + * Author: Tomer Maimon <tomer.maimon@nuvoton.com>
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/clk-provider.h>
> > +#include <linux/err.h>
> > +#include <linux/io.h>
> > +#include <linux/kernel.h>
> > +#include <linux/of.h>
> > +#include <linux/of_address.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +
> > +#include <dt-bindings/clock/nuvoton,npcm845-clk.h>
> > +
> > +#define NPCM8XX_REF_CLK                25000000
> > +
> > +struct npcm8xx_clk_pll {
> > +       struct clk_hw   hw;
> > +       void __iomem    *pllcon;
> > +       u8              flags;
> > +};
> > +
> > +#define to_npcm8xx_clk_pll(_hw) container_of(_hw, struct npcm8xx_clk_pll, hw)
> > +
> > +#define PLLCON_LOKI    BIT(31)
> > +#define PLLCON_LOKS    BIT(30)
> > +#define PLLCON_FBDV    GENMASK(27, 16)
> > +#define PLLCON_OTDV2   GENMASK(15, 13)
> > +#define PLLCON_PWDEN   BIT(12)
> > +#define PLLCON_OTDV1   GENMASK(10, 8)
> > +#define PLLCON_INDV    GENMASK(5, 0)
> > +
> > +static unsigned long npcm8xx_clk_pll_recalc_rate(struct clk_hw *hw,
> > +                                                unsigned long parent_rate)
> > +{
> > +       struct npcm8xx_clk_pll *pll = to_npcm8xx_clk_pll(hw);
> > +       unsigned long fbdv, indv, otdv1, otdv2;
> > +       unsigned int val;
> > +       u64 ret;
> > +
> > +       if (parent_rate == 0) {
> > +               pr_debug("%s: parent rate is zero\n", __func__);
> > +               return 0;
> > +       }
> > +
> > +       val = readl_relaxed(pll->pllcon);
> > +
> > +       indv = FIELD_GET(PLLCON_INDV, val);
> > +       fbdv = FIELD_GET(PLLCON_FBDV, val);
> > +       otdv1 = FIELD_GET(PLLCON_OTDV1, val);
> > +       otdv2 = FIELD_GET(PLLCON_OTDV2, val);
> > +
> > +       ret = (u64)parent_rate * fbdv;
> > +       do_div(ret, indv * otdv1 * otdv2);
> > +
> > +       return ret;
> > +}
> > +
> > +static const struct clk_ops npcm8xx_clk_pll_ops = {
> > +       .recalc_rate = npcm8xx_clk_pll_recalc_rate,
> > +};
> > +
> > +static struct clk_hw *
> > +npcm8xx_clk_register_pll(struct device *dev, void __iomem *pllcon,
> > +                        const char *name, const char *parent_name,
> > +                        unsigned long flags)
> > +{
> > +       struct npcm8xx_clk_pll *pll;
> > +       struct clk_init_data init;
> > +       struct clk_hw *hw;
> > +       int ret;
> > +
> > +       pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
> > +       if (!pll)
> > +               return ERR_PTR(-ENOMEM);
> > +
> > +       pr_debug("%s reg, name=%s, p=%s\n", __func__, name, parent_name);
> > +
> > +       init.name = name;
> > +       init.ops = &npcm8xx_clk_pll_ops;
> > +       init.parent_names = &parent_name;
> > +       init.num_parents = 1;
> > +       init.flags = flags;
> > +
> > +       pll->pllcon = pllcon;
> > +       pll->hw.init = &init;
> > +
> > +       hw = &pll->hw;
> > +
> > +       ret = devm_clk_hw_register(dev, hw);
> > +       if (ret)
> > +               return ERR_PTR(ret);
> > +
> > +       return hw;
> > +}
> > +
> > +#define NPCM8XX_CLKEN1          (0x00)
> > +#define NPCM8XX_CLKEN2          (0x28)
> > +#define NPCM8XX_CLKEN3          (0x30)
> > +#define NPCM8XX_CLKEN4          (0x70)
> > +#define NPCM8XX_CLKSEL          (0x04)
> > +#define NPCM8XX_CLKDIV1         (0x08)
> > +#define NPCM8XX_CLKDIV2         (0x2C)
> > +#define NPCM8XX_CLKDIV3         (0x58)
> > +#define NPCM8XX_CLKDIV4         (0x7C)
> > +#define NPCM8XX_PLLCON0         (0x0C)
> > +#define NPCM8XX_PLLCON1         (0x10)
> > +#define NPCM8XX_PLLCON2         (0x54)
> > +#define NPCM8XX_SWRSTR          (0x14)
> > +#define NPCM8XX_IRQWAKECON      (0x18)
> > +#define NPCM8XX_IRQWAKEFLAG     (0x1C)
> > +#define NPCM8XX_IPSRST1         (0x20)
> > +#define NPCM8XX_IPSRST2         (0x24)
> > +#define NPCM8XX_IPSRST3         (0x34)
> > +#define NPCM8XX_WD0RCR          (0x38)
> > +#define NPCM8XX_WD1RCR          (0x3C)
> > +#define NPCM8XX_WD2RCR          (0x40)
> > +#define NPCM8XX_SWRSTC1         (0x44)
> > +#define NPCM8XX_SWRSTC2         (0x48)
> > +#define NPCM8XX_SWRSTC3         (0x4C)
> > +#define NPCM8XX_SWRSTC4         (0x50)
> > +#define NPCM8XX_CORSTC          (0x5C)
> > +#define NPCM8XX_PLLCONG         (0x60)
> > +#define NPCM8XX_AHBCKFI         (0x64)
> > +#define NPCM8XX_SECCNT          (0x68)
> > +#define NPCM8XX_CNTR25M         (0x6C)
> > +#define NPCM8XX_THRTL_CNT       (0xC0)
> > +
> > +struct npcm8xx_clk_mux_data {
> > +       u8 shift;
> > +       u8 mask;
> > +       u32 *table;
> > +       const char *name;
> > +       const char * const *parent_names;
> > +       u8 num_parents;
> > +       unsigned long flags;
> > +       /*
> > +        * If this clock is exported via DT, set onecell_idx to constant
> > +        * defined in include/dt-bindings/clock/nuvoton, NPCM8XX-clock.h for
> > +        * this specific clock.  Otherwise, set to -1.
> > +        */
> > +       int onecell_idx;
> > +};
> > +
> > +struct npcm8xx_clk_div_data {
> > +       u32 reg;
> > +       u8 shift;
> > +       u8 width;
> > +       const char *name;
> > +       const char *parent_name;
> > +       u8 clk_divider_flags;
> > +       unsigned long flags;
> > +       /*
> > +        * If this clock is exported via DT, set onecell_idx to constant
> > +        * defined in include/dt-bindings/clock/nuvoton, NPCM8XX-clock.h for
> > +        * this specific clock.  Otherwise, set to -1.
> > +        */
> > +       int onecell_idx;
> > +};
> > +
> > +struct npcm8xx_clk_pll_data {
> > +       u32 reg;
> > +       const char *name;
> > +       const char *parent_name;
>
> Any reason why we're not using clk_parent_data or direct clk_hw
> pointers?
For more historical reasons, I did the same method as done in the
NPCM7XX driver.
The clk_init_data struct can use * const *parent_names,
https://elixir.bootlin.com/linux/v5.19-rc6/source/include/linux/clk-provider.h#L289
Is it problematic?
>
> > +       unsigned long flags;
> > +       /*
> > +        * If this clock is exported via DT, set onecell_idx to constant
> > +        * defined in include/dt-bindings/clock/nuvoton, NPCM8XX-clock.h for
> > +        * this specific clock.  Otherwise, set to -1.
> > +        */
> > +       int onecell_idx;
> > +};
> > +
> > +/*
> > + * Single copy of strings used to refer to clocks within this driver indexed by
> > + * above enum.
> > + */
> > +#define NPCM8XX_CLK_S_REFCLK      "refclk"
> > +#define NPCM8XX_CLK_S_SYSBYPCK    "sysbypck"
> > +#define NPCM8XX_CLK_S_MCBYPCK     "mcbypck"
> > +#define NPCM8XX_CLK_S_PLL0        "pll0"
> > +#define NPCM8XX_CLK_S_PLL1        "pll1"
> > +#define NPCM8XX_CLK_S_PLL1_DIV2   "pll1_div2"
> > +#define NPCM8XX_CLK_S_PLL2        "pll2"
> > +#define NPCM8XX_CLK_S_PLL_GFX     "pll_gfx"
> > +#define NPCM8XX_CLK_S_PLL2_DIV2   "pll2_div2"
> > +#define NPCM8XX_CLK_S_PIX_MUX     "gfx_pixel"
> > +#define NPCM8XX_CLK_S_MC_MUX      "mc_phy"
> > +#define NPCM8XX_CLK_S_CPU_MUX     "cpu"  /* AKA system clock */
> > +#define NPCM8XX_CLK_S_MC          "mc"
> > +#define NPCM8XX_CLK_S_AXI         "axi"  /* AKA CLK2 */
> > +#define NPCM8XX_CLK_S_AHB         "ahb"  /* AKA CLK4 */
> > +#define NPCM8XX_CLK_S_CLKOUT_MUX  "clkout_mux"
> > +#define NPCM8XX_CLK_S_UART_MUX    "uart_mux"
> > +#define NPCM8XX_CLK_S_SD_MUX      "sd_mux"
> > +#define NPCM8XX_CLK_S_GFXM_MUX    "gfxm_mux"
> > +#define NPCM8XX_CLK_S_SU_MUX      "serial_usb_mux"
> > +#define NPCM8XX_CLK_S_DVC_MUX     "dvc_mux"
> > +#define NPCM8XX_CLK_S_GFX_MUX     "gfx_mux"
> > +#define NPCM8XX_CLK_S_ADC_MUX     "adc_mux"
> > +#define NPCM8XX_CLK_S_SPI0        "spi0"
> > +#define NPCM8XX_CLK_S_SPI1        "spi1"
> > +#define NPCM8XX_CLK_S_SPI3        "spi3"
> > +#define NPCM8XX_CLK_S_SPIX        "spix"
> > +#define NPCM8XX_CLK_S_APB1        "apb1"
> > +#define NPCM8XX_CLK_S_APB2        "apb2"
> > +#define NPCM8XX_CLK_S_APB3        "apb3"
> > +#define NPCM8XX_CLK_S_APB4        "apb4"
> > +#define NPCM8XX_CLK_S_APB5        "apb5"
> > +#define NPCM8XX_CLK_S_APB19       "apb19"
> > +#define NPCM8XX_CLK_S_TOCK        "tock"
> > +#define NPCM8XX_CLK_S_CLKOUT      "clkout"
> > +#define NPCM8XX_CLK_S_PRE_ADC     "pre adc"
> > +#define NPCM8XX_CLK_S_UART        "uart"
> > +#define NPCM8XX_CLK_S_UART2       "uart2"
> > +#define NPCM8XX_CLK_S_TIMER       "timer"
> > +#define NPCM8XX_CLK_S_MMC         "mmc"
> > +#define NPCM8XX_CLK_S_SDHC        "sdhc"
> > +#define NPCM8XX_CLK_S_ADC         "adc"
> > +#define NPCM8XX_CLK_S_GFX         "gfx0_gfx1_mem"
> > +#define NPCM8XX_CLK_S_USBIF       "serial_usbif"
> > +#define NPCM8XX_CLK_S_USB_HOST    "usb_host"
> > +#define NPCM8XX_CLK_S_USB_BRIDGE  "usb_bridge"
> > +#define NPCM8XX_CLK_S_PCI         "pci"
> > +#define NPCM8XX_CLK_S_TH          "th"
> > +#define NPCM8XX_CLK_S_ATB         "atb"
> > +#define NPCM8XX_CLK_S_PRE_CLK     "pre_clk"
> > +
> > +#define NPCM8XX_CLK_S_RG_MUX     "rg_mux"
> > +#define NPCM8XX_CLK_S_RCP_MUX    "rcp_mux"
> > +#define NPCM8XX_CLK_S_RG         "rg"
> > +#define NPCM8XX_CLK_S_RCP        "rcp"
> > +
> > +static u32 pll_mux_table[] = {0, 1, 2, 3};
> > +static const char * const pll_mux_parents[] = {
> > +       NPCM8XX_CLK_S_PLL0,
> > +       NPCM8XX_CLK_S_PLL1,
> > +       NPCM8XX_CLK_S_REFCLK,
> > +       NPCM8XX_CLK_S_PLL2_DIV2,
> > +};
> > +
> > +static u32 cpuck_mux_table[] = {0, 1, 2, 3, 7};
> > +static const char * const cpuck_mux_parents[] = {
> > +       NPCM8XX_CLK_S_PLL0,
> > +       NPCM8XX_CLK_S_PLL1,
> > +       NPCM8XX_CLK_S_REFCLK,
> > +       NPCM8XX_CLK_S_SYSBYPCK,
> > +       NPCM8XX_CLK_S_PLL2,
> > +};
> > +
> > +static u32 pixcksel_mux_table[] = {0, 2};
> > +static const char * const pixcksel_mux_parents[] = {
> > +       NPCM8XX_CLK_S_PLL_GFX,
> > +       NPCM8XX_CLK_S_REFCLK,
> > +};
> > +
> > +static u32 sucksel_mux_table[] = {2, 3};
> > +static const char * const sucksel_mux_parents[] = {
> > +       NPCM8XX_CLK_S_REFCLK,
> > +       NPCM8XX_CLK_S_PLL2_DIV2,
> > +};
> > +
> > +static u32 mccksel_mux_table[] = {0, 2, 3};
> > +static const char * const mccksel_mux_parents[] = {
> > +       NPCM8XX_CLK_S_PLL1_DIV2,
> > +       NPCM8XX_CLK_S_REFCLK,
> > +       NPCM8XX_CLK_S_MCBYPCK,
> > +};
> > +
> > +static u32 clkoutsel_mux_table[] = {0, 1, 2, 3, 4};
> > +static const char * const clkoutsel_mux_parents[] = {
> > +       NPCM8XX_CLK_S_PLL0,
> > +       NPCM8XX_CLK_S_PLL1,
> > +       NPCM8XX_CLK_S_REFCLK,
> > +       NPCM8XX_CLK_S_PLL_GFX, // divided by 2
> > +       NPCM8XX_CLK_S_PLL2_DIV2,
> > +};
> > +
> > +static u32 gfxmsel_mux_table[] = {2, 3};
> > +static const char * const gfxmsel_mux_parents[] = {
> > +       NPCM8XX_CLK_S_REFCLK,
> > +       NPCM8XX_CLK_S_PLL2_DIV2,
> > +};
> > +
> > +static u32 dvcssel_mux_table[] = {2, 3};
> > +static const char * const dvcssel_mux_parents[] = {
> > +       NPCM8XX_CLK_S_REFCLK,
> > +       NPCM8XX_CLK_S_PLL2,
> > +};
> > +
> > +static const struct npcm8xx_clk_pll_data npcm8xx_plls[] = {
> > +       {NPCM8XX_PLLCON0, NPCM8XX_CLK_S_PLL0, NPCM8XX_CLK_S_REFCLK, 0, -1},
> > +       {NPCM8XX_PLLCON1, NPCM8XX_CLK_S_PLL1, NPCM8XX_CLK_S_REFCLK, 0, -1},
> > +       {NPCM8XX_PLLCON2, NPCM8XX_CLK_S_PLL2, NPCM8XX_CLK_S_REFCLK, 0, -1},
> > +       {NPCM8XX_PLLCONG, NPCM8XX_CLK_S_PLL_GFX, NPCM8XX_CLK_S_REFCLK, 0, -1},
> > +};
> > +
> > +static const struct npcm8xx_clk_mux_data npcm8xx_muxes[] = {
> > +       {0, GENMASK(1, 0), cpuck_mux_table, NPCM8XX_CLK_S_CPU_MUX,
> > +       cpuck_mux_parents, ARRAY_SIZE(cpuck_mux_parents), CLK_IS_CRITICAL,
> > +       NPCM8XX_CLK_CPU},
> > +
> > +       {4, GENMASK(1, 0), pixcksel_mux_table, NPCM8XX_CLK_S_PIX_MUX,
> > +       pixcksel_mux_parents, ARRAY_SIZE(pixcksel_mux_parents), 0,
> > +       NPCM8XX_CLK_GFX_PIXEL},
> > +
> > +       {6, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_SD_MUX,
> > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > +
> > +       {8, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_UART_MUX,
> > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > +
> > +       {10, GENMASK(1, 0), sucksel_mux_table, NPCM8XX_CLK_S_SU_MUX,
> > +       sucksel_mux_parents, ARRAY_SIZE(sucksel_mux_parents), 0, -1},
> > +
> > +       {12, GENMASK(1, 0), mccksel_mux_table, NPCM8XX_CLK_S_MC_MUX,
> > +       mccksel_mux_parents, ARRAY_SIZE(mccksel_mux_parents), 0, -1},
> > +
> > +       {14, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_ADC_MUX,
> > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > +
> > +       {16, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_GFX_MUX,
> > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > +
> > +       {18, GENMASK(2, 0), clkoutsel_mux_table, NPCM8XX_CLK_S_CLKOUT_MUX,
> > +       clkoutsel_mux_parents, ARRAY_SIZE(clkoutsel_mux_parents), 0, -1},
> > +
> > +       {21, GENMASK(1, 0), gfxmsel_mux_table, NPCM8XX_CLK_S_GFXM_MUX,
> > +       gfxmsel_mux_parents, ARRAY_SIZE(gfxmsel_mux_parents), 0, -1},
> > +
> > +       {23, GENMASK(1, 0), dvcssel_mux_table, NPCM8XX_CLK_S_DVC_MUX,
> > +       dvcssel_mux_parents, ARRAY_SIZE(dvcssel_mux_parents), 0, -1},
> > +
> > +       {25, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_RG_MUX,
> > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > +
> > +       {27, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_RCP_MUX,
> > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > +};
> > +
> > +/* configurable dividers: */
> > +static const struct npcm8xx_clk_div_data npcm8xx_divs[] = {
> > +       {NPCM8XX_CLKDIV1, 28, 3, NPCM8XX_CLK_S_ADC, NPCM8XX_CLK_S_PRE_ADC,
> > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > +               NPCM8XX_CLK_ADC},
> > +       /* bit 30-28 ADCCKDIV*/
> > +       {NPCM8XX_CLKDIV1, 26, 2, NPCM8XX_CLK_S_AHB, NPCM8XX_CLK_S_PRE_CLK,
> > +               CLK_DIVIDER_READ_ONLY, CLK_IS_CRITICAL, NPCM8XX_CLK_AHB},
> > +       /* bit 28-26 CLK4DIV*/
> > +       {NPCM8XX_CLKDIV1, 21, 5, NPCM8XX_CLK_S_PRE_ADC,
> > +       NPCM8XX_CLK_S_ADC_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_PRE_ADC},
> > +       /* bit 25-21 PRE-ADCCKDIV*/
> > +       {NPCM8XX_CLKDIV1, 16, 5, NPCM8XX_CLK_S_UART,
> > +       NPCM8XX_CLK_S_UART_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_UART},
> > +       /* bit 20-16 UARTDIV*/
> > +       {NPCM8XX_CLKDIV1, 11, 5, NPCM8XX_CLK_S_MMC,
> > +       NPCM8XX_CLK_S_SD_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_MMC},
> > +       /* bit 15-11 MMCCKDIV*/
> > +       {NPCM8XX_CLKDIV1, 6, 5, NPCM8XX_CLK_S_SPI3,
> > +       NPCM8XX_CLK_S_AHB, 0, 0, NPCM8XX_CLK_SPI3},
> > +       /* bit 10-6 AHB3CKDIV*/
> > +       {NPCM8XX_CLKDIV1, 2, 4, NPCM8XX_CLK_S_PCI,
> > +       NPCM8XX_CLK_S_GFX_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_PCI},
> > +       /* bit 5-2 PCICKDIV*/
> > +
> > +       {NPCM8XX_CLKDIV2, 30, 2, NPCM8XX_CLK_S_APB4, NPCM8XX_CLK_S_AHB,
> > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > +               NPCM8XX_CLK_APB4},
> > +       /* bit 31-30 APB4CKDIV*/
> > +       {NPCM8XX_CLKDIV2, 28, 2, NPCM8XX_CLK_S_APB3, NPCM8XX_CLK_S_AHB,
> > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > +               NPCM8XX_CLK_APB3},
> > +       /* bit 29-28 APB3CKDIV*/
> > +       {NPCM8XX_CLKDIV2, 26, 2, NPCM8XX_CLK_S_APB2, NPCM8XX_CLK_S_AHB,
> > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > +               NPCM8XX_CLK_APB2},
> > +       /* bit 28-26 APB2CKDIV*/
> > +       {NPCM8XX_CLKDIV2, 24, 2, NPCM8XX_CLK_S_APB1, NPCM8XX_CLK_S_AHB,
> > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > +               NPCM8XX_CLK_APB1},
> > +       /* bit 25-24 APB1CKDIV*/
> > +       {NPCM8XX_CLKDIV2, 22, 2, NPCM8XX_CLK_S_APB5, NPCM8XX_CLK_S_AHB,
> > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > +               NPCM8XX_CLK_APB5},
> > +       /* bit 23-22 APB5CKDIV*/
> > +       {NPCM8XX_CLKDIV2, 16, 5, NPCM8XX_CLK_S_CLKOUT, NPCM8XX_CLK_S_CLKOUT_MUX,
> > +                CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_CLKOUT},
> > +       /* bit 20-16 CLKOUTDIV*/
> > +       {NPCM8XX_CLKDIV2, 13, 3, NPCM8XX_CLK_S_GFX, NPCM8XX_CLK_S_GFX_MUX,
> > +               CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_GFX},
> > +       /* bit 15-13 GFXCKDIV*/
> > +       {NPCM8XX_CLKDIV2, 8, 5, NPCM8XX_CLK_S_USB_BRIDGE, NPCM8XX_CLK_S_SU_MUX,
> > +               CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SU},
> > +       /* bit 12-8 SUCKDIV*/
> > +       {NPCM8XX_CLKDIV2, 4, 4, NPCM8XX_CLK_S_USB_HOST, NPCM8XX_CLK_S_SU_MUX,
> > +               CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SU48},
> > +       /* bit 8-4 SU48CKDIV*/
> > +       {NPCM8XX_CLKDIV2, 0, 4, NPCM8XX_CLK_S_SDHC,
> > +       NPCM8XX_CLK_S_SD_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SDHC}
> > +       ,/* bit 3-0 SD1CKDIV*/
> > +
> > +       {NPCM8XX_CLKDIV3, 16, 8, NPCM8XX_CLK_S_SPI1,
> > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPI1},
> > +       /* bit 23-16 SPI1CKDV*/
> > +       {NPCM8XX_CLKDIV3, 11, 5, NPCM8XX_CLK_S_UART2,
> > +       NPCM8XX_CLK_S_UART_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_UART2},
> > +       /* bit 15-11 UARTDIV2*/
> > +       {NPCM8XX_CLKDIV3, 6, 5, NPCM8XX_CLK_S_SPI0,
>
> Please run checkpatch, add a space after '{' and before '}'
I did run checkpatch, it weird I didn't got a warning about it.
will be fixed.
>
> > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPI0},
> > +       /* bit 10-6 SPI0CKDV*/
> > +       {NPCM8XX_CLKDIV3, 1, 5, NPCM8XX_CLK_S_SPIX,
> > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPIX},
> > +       /* bit 5-1 SPIXCKDV*/
> > +
> > +       {NPCM8XX_CLKDIV4, 28, 4, NPCM8XX_CLK_S_RG, NPCM8XX_CLK_S_RG_MUX,
> > +       CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_RG},
> > +       /* bit 31-28 RGREFDIV*/
> > +       {NPCM8XX_CLKDIV4, 12, 4, NPCM8XX_CLK_S_RCP, NPCM8XX_CLK_S_RCP_MUX,
> > +       CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_RCP},
> > +       /* bit 15-12 RCPREFDIV*/
> > +       {NPCM8XX_THRTL_CNT, 0, 2, NPCM8XX_CLK_S_TH, NPCM8XX_CLK_S_CPU_MUX,
> > +       CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0, NPCM8XX_CLK_TH},
> > +       /* bit 1-0 TH_DIV*/
> > +};
> > +
> > +static DEFINE_SPINLOCK(npcm8xx_clk_lock);
> > +
> > +static int npcm8xx_clk_probe(struct platform_device *pdev)
> > +{
> > +       struct clk_hw_onecell_data *npcm8xx_clk_data;
> > +       struct device *dev = &pdev->dev;
> > +       struct device_node *np = dev->of_node;
> > +       void __iomem *clk_base;
> > +       struct resource res;
> > +       struct clk_hw *hw;
> > +       int i, err;
> > +
> > +       npcm8xx_clk_data = devm_kzalloc(dev, struct_size(npcm8xx_clk_data, hws,
> > +                                                        NPCM8XX_NUM_CLOCKS),
> > +                                       GFP_KERNEL);
> > +       if (!npcm8xx_clk_data)
> > +               return -ENOMEM;
> > +
> > +       err = of_address_to_resource(np, 0, &res);
>
> Why can't we use platform_get_resource()?
>
> > +       if (err) {
> > +               dev_err(dev, "Failed to get resource, ret %d\n", err);
> > +               return err;
> > +       }
> > +
> > +       clk_base = ioremap(res.start, resource_size(&res));
>
> And use devm_platform_ioremap_resource()?
Clock and reset driver use the same memory register map 0xF0801000 - 0xF0801FFF.
For historical reasons the registers of both modules are mixed in the
memory range 0xF0801000 - 0xF0801FFF this is why we can't have a
separate region for each module.
In case I will use devm_platform_ioremap_resource function the reset
ioremap will fail so the driver using the method above.
>
> > +       if (!clk_base) {
> > +               dev_err(&pdev->dev, "Failed to remap I/O memory\n");
> > +               return -ENOMEM;
> > +       }
> > +
> > +       npcm8xx_clk_data->num = NPCM8XX_NUM_CLOCKS;
> > +
> > +       for (i = 0; i < NPCM8XX_NUM_CLOCKS; i++)
> > +               npcm8xx_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
> > +
> > +       /* Reference 25MHz clock */
>
> Does this exist on the board? If so, I'd make a fixed rate clk in the
> dts and have 'refclk' be an input in the binding for this clk controller.
No, it is an internal clock in the SoC, this is why it is in the driver.
>
> > +       hw = clk_hw_register_fixed_rate(dev, "refclk", NULL, 0, NPCM8XX_REF_CLK);
> > +       if (IS_ERR(hw))
> > +               return PTR_ERR(hw);
> > +       npcm8xx_clk_data->hws[NPCM8XX_CLK_REFCLK] = hw;
> > +
> > +       /* Register plls */
> > +       for (i = 0; i < ARRAY_SIZE(npcm8xx_plls); i++) {
> > +               const struct npcm8xx_clk_pll_data *pll_data = &npcm8xx_plls[i];
> > +
> > +               hw = npcm8xx_clk_register_pll(dev, clk_base + pll_data->reg,
> > +                                             pll_data->name,
> > +                                             pll_data->parent_name,
> > +                                             pll_data->flags);
> > +               if (IS_ERR(hw)) {
> > +                       dev_err(dev, "npcm8xx_clk: Can't register pll\n");
> > +                       goto unregister_refclk;
> > +               }
> > +
> > +               if (pll_data->onecell_idx >= 0)
> > +                       npcm8xx_clk_data->hws[pll_data->onecell_idx] = hw;
> > +       }
> > +
> > +       /* Register fixed dividers */
> > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_PLL1_DIV2,
> > +                                              NPCM8XX_CLK_S_PLL1, 0, 1, 2);
> > +       if (IS_ERR(hw)) {
> > +               dev_err(dev, "npcm8xx_clk: Can't register fixed div\n");
> > +               goto unregister_refclk;
> > +       }
> > +
> > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_PLL2_DIV2,
> > +                                              NPCM8XX_CLK_S_PLL2, 0, 1, 2);
> > +       if (IS_ERR(hw)) {
> > +               dev_err(dev, "npcm8xx_clk: Can't register pll div2\n");
> > +               goto unregister_refclk;
> > +       }
> > +
> > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_PRE_CLK,
> > +                                              NPCM8XX_CLK_S_CPU_MUX, 0, 1, 2);
> > +       if (IS_ERR(hw)) {
> > +               dev_err(dev, "npcm8xx_clk: Can't register ckclk div2\n");
> > +               goto unregister_refclk;
> > +       }
> > +
> > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_AXI,
> > +                                              NPCM8XX_CLK_S_TH, 0, 1, 2);
> > +       if (IS_ERR(hw)) {
> > +               dev_err(dev, "npcm8xx_clk: Can't register axi div2\n");
> > +               goto unregister_refclk;
> > +       }
> > +
> > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_ATB,
> > +                                              NPCM8XX_CLK_S_AXI, 0, 1, 2);
> > +       if (IS_ERR(hw)) {
> > +               dev_err(dev, "npcm8xx_clk: Can't register atb div2\n");
> > +               goto unregister_refclk;
> > +       }
> > +
> > +       /* Register clock dividers specified in npcm8xx_divs */
> > +       for (i = 0; i < ARRAY_SIZE(npcm8xx_divs); i++) {
> > +               const struct npcm8xx_clk_div_data *div_data = &npcm8xx_divs[i];
> > +
> > +               hw = devm_clk_hw_register_divider(dev, div_data->name,
> > +                                                 div_data->parent_name,
> > +                                                 div_data->flags,
> > +                                                 clk_base + div_data->reg,
> > +                                                 div_data->shift,
> > +                                                 div_data->width,
> > +                                                 div_data->clk_divider_flags,
> > +                                                 &npcm8xx_clk_lock);
> > +               if (IS_ERR(hw)) {
> > +                       dev_err(dev, "npcm8xx_clk: Can't register div table\n");
> > +                       goto unregister_refclk;
> > +               }
> > +
> > +               if (div_data->onecell_idx >= 0)
> > +                       npcm8xx_clk_data->hws[div_data->onecell_idx] = hw;
> > +       }
> > +
> > +       /* Register muxes */
> > +       for (i = 0; i < ARRAY_SIZE(npcm8xx_muxes); i++) {
> > +               const struct npcm8xx_clk_mux_data *mux_data = &npcm8xx_muxes[i];
> > +
> > +               hw = clk_hw_register_mux_table(dev, mux_data->name,
> > +                                              mux_data->parent_names,
> > +                                              mux_data->num_parents,
> > +                                              mux_data->flags,
> > +                                              clk_base + NPCM8XX_CLKSEL,
> > +                                              mux_data->shift,
> > +                                              mux_data->mask, 0,
> > +                                              mux_data->table,
> > +                                              &npcm8xx_clk_lock);
> > +
> > +               if (IS_ERR(hw)) {
> > +                       dev_err(dev, "npcm8xx_clk: Can't register mux\n");
> > +                       goto err_mux_clk;
> > +               }
> > +
> > +               if (mux_data->onecell_idx >= 0)
> > +                       npcm8xx_clk_data->hws[mux_data->onecell_idx] = hw;
> > +       }
> > +
> > +       err = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
> > +                                         npcm8xx_clk_data);
> > +       if (err) {
> > +               dev_err(dev, "unable to add clk provider\n");
> > +               goto unregister_refclk;
>
> The 'hw' pointer doesn't contain 'err' here so probe will return some
> positive number when this fails?
Indeed, will be fixed.
>
> > +       }
> > +
> > +       return err;
> > +
> > +err_mux_clk:
> > +       while (i--) {
> > +               if (npcm8xx_muxes[i].onecell_idx >= 0)
> > +                       clk_hw_unregister_mux(npcm8xx_clk_data->hws[npcm8xx_muxes[i].onecell_idx]);
> > +       }
> > +unregister_refclk:
> > +       clk_hw_unregister(npcm8xx_clk_data->hws[NPCM8XX_CLK_REFCLK]);
> > +       return PTR_ERR(hw);
> > +}
> > +
> > +static const struct of_device_id npcm8xx_clk_dt_ids[] = {
> > +       { .compatible = "nuvoton,npcm845-clk", },
> > +       { }
> > +};
> > +MODULE_DEVICE_TABLE(of, npcm8xx_clk_dt_ids);
> > +
> > +static struct platform_driver npcm8xx_clk_driver = {
> > +       .probe  = npcm8xx_clk_probe,
> > +       .driver = {
> > +               .name = "npcm8xx_clk",
> > +               .of_match_table = npcm8xx_clk_dt_ids,
> > +       },
> > +};
> > +
> > +static int __init npcm8xx_clk_driver_init(void)
> > +{
> > +       return platform_driver_register(&npcm8xx_clk_driver);
> > +}
> > +arch_initcall(npcm8xx_clk_driver_init);
> > +
>
> If it can be a module it needs to unregister the driver on module exit.
Will remove the MODULE_DEVICE_TABLE, the driver clock should be a
built-in kernel driver.

Thanks,

Tomer
Tomer Maimon July 14, 2022, 6:23 p.m. UTC | #2
Hi Stephen,

Appreciate if you can address my answers to your comments

On Tue, 12 Jul 2022 at 10:28, Tomer Maimon <tmaimon77@gmail.com> wrote:
>
> Hi Stephen,
>
> Thanks for your comments
>
> On Mon, 11 Jul 2022 at 22:55, Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Tomer Maimon (2022-07-11 05:35:07)
> > > Nuvoton Arbel BMC NPCM8XX contains an integrated clock controller which
> > > generates and supplies clocks to all modules within the BMC.
> > >
> > > Signed-off-by: Tomer Maimon <tmaimon77@gmail.com>
> > > ---
> > >  drivers/clk/Kconfig       |   6 +
> > >  drivers/clk/Makefile      |   1 +
> > >  drivers/clk/clk-npcm8xx.c | 610 ++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 617 insertions(+)
> > >  create mode 100644 drivers/clk/clk-npcm8xx.c
> > >
> > > diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> > > index 48f8f4221e21..9aa915f6e233 100644
> > > --- a/drivers/clk/Kconfig
> > > +++ b/drivers/clk/Kconfig
> > > @@ -428,6 +428,12 @@ config COMMON_CLK_K210
> > >         help
> > >           Support for the Canaan Kendryte K210 RISC-V SoC clocks.
> > >
> > > +config COMMON_CLK_NPCM8XX
> > > +       tristate "Clock driver for the NPCM8XX SoC Family"
> > > +       depends on ARCH_NPCM || COMPILE_TEST
> > > +       help
> > > +          This driver supports the clocks on the Nuvoton BMC NPCM8XX SoC Family.
> >
> > Please put this next to COMMON_CLK_NXP so that it is sort of sorted
> > based on Kconfig symbol.
> Will do
> > > +
> > >  source "drivers/clk/actions/Kconfig"
> > >  source "drivers/clk/analogbits/Kconfig"
> > >  source "drivers/clk/baikal-t1/Kconfig"
> > > diff --git a/drivers/clk/clk-npcm8xx.c b/drivers/clk/clk-npcm8xx.c
> > > new file mode 100644
> > > index 000000000000..392f1fbba49b
> > > --- /dev/null
> > > +++ b/drivers/clk/clk-npcm8xx.c
> > > @@ -0,0 +1,610 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * Nuvoton NPCM8xx Clock Generator
> > > + * All the clocks are initialized by the bootloader, so this driver allow only
> > > + * reading of current settings directly from the hardware.
> > > + *
> > > + * Copyright (C) 2020 Nuvoton Technologies
> > > + * Author: Tomer Maimon <tomer.maimon@nuvoton.com>
> > > + */
> > > +
> > > +#include <linux/bitfield.h>
> > > +#include <linux/clk-provider.h>
> > > +#include <linux/err.h>
> > > +#include <linux/io.h>
> > > +#include <linux/kernel.h>
> > > +#include <linux/of.h>
> > > +#include <linux/of_address.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/slab.h>
> > > +
> > > +#include <dt-bindings/clock/nuvoton,npcm845-clk.h>
> > > +
> > > +#define NPCM8XX_REF_CLK                25000000
> > > +
> > > +struct npcm8xx_clk_pll {
> > > +       struct clk_hw   hw;
> > > +       void __iomem    *pllcon;
> > > +       u8              flags;
> > > +};
> > > +
> > > +#define to_npcm8xx_clk_pll(_hw) container_of(_hw, struct npcm8xx_clk_pll, hw)
> > > +
> > > +#define PLLCON_LOKI    BIT(31)
> > > +#define PLLCON_LOKS    BIT(30)
> > > +#define PLLCON_FBDV    GENMASK(27, 16)
> > > +#define PLLCON_OTDV2   GENMASK(15, 13)
> > > +#define PLLCON_PWDEN   BIT(12)
> > > +#define PLLCON_OTDV1   GENMASK(10, 8)
> > > +#define PLLCON_INDV    GENMASK(5, 0)
> > > +
> > > +static unsigned long npcm8xx_clk_pll_recalc_rate(struct clk_hw *hw,
> > > +                                                unsigned long parent_rate)
> > > +{
> > > +       struct npcm8xx_clk_pll *pll = to_npcm8xx_clk_pll(hw);
> > > +       unsigned long fbdv, indv, otdv1, otdv2;
> > > +       unsigned int val;
> > > +       u64 ret;
> > > +
> > > +       if (parent_rate == 0) {
> > > +               pr_debug("%s: parent rate is zero\n", __func__);
> > > +               return 0;
> > > +       }
> > > +
> > > +       val = readl_relaxed(pll->pllcon);
> > > +
> > > +       indv = FIELD_GET(PLLCON_INDV, val);
> > > +       fbdv = FIELD_GET(PLLCON_FBDV, val);
> > > +       otdv1 = FIELD_GET(PLLCON_OTDV1, val);
> > > +       otdv2 = FIELD_GET(PLLCON_OTDV2, val);
> > > +
> > > +       ret = (u64)parent_rate * fbdv;
> > > +       do_div(ret, indv * otdv1 * otdv2);
> > > +
> > > +       return ret;
> > > +}
> > > +
> > > +static const struct clk_ops npcm8xx_clk_pll_ops = {
> > > +       .recalc_rate = npcm8xx_clk_pll_recalc_rate,
> > > +};
> > > +
> > > +static struct clk_hw *
> > > +npcm8xx_clk_register_pll(struct device *dev, void __iomem *pllcon,
> > > +                        const char *name, const char *parent_name,
> > > +                        unsigned long flags)
> > > +{
> > > +       struct npcm8xx_clk_pll *pll;
> > > +       struct clk_init_data init;
> > > +       struct clk_hw *hw;
> > > +       int ret;
> > > +
> > > +       pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
> > > +       if (!pll)
> > > +               return ERR_PTR(-ENOMEM);
> > > +
> > > +       pr_debug("%s reg, name=%s, p=%s\n", __func__, name, parent_name);
> > > +
> > > +       init.name = name;
> > > +       init.ops = &npcm8xx_clk_pll_ops;
> > > +       init.parent_names = &parent_name;
> > > +       init.num_parents = 1;
> > > +       init.flags = flags;
> > > +
> > > +       pll->pllcon = pllcon;
> > > +       pll->hw.init = &init;
> > > +
> > > +       hw = &pll->hw;
> > > +
> > > +       ret = devm_clk_hw_register(dev, hw);
> > > +       if (ret)
> > > +               return ERR_PTR(ret);
> > > +
> > > +       return hw;
> > > +}
> > > +
> > > +#define NPCM8XX_CLKEN1          (0x00)
> > > +#define NPCM8XX_CLKEN2          (0x28)
> > > +#define NPCM8XX_CLKEN3          (0x30)
> > > +#define NPCM8XX_CLKEN4          (0x70)
> > > +#define NPCM8XX_CLKSEL          (0x04)
> > > +#define NPCM8XX_CLKDIV1         (0x08)
> > > +#define NPCM8XX_CLKDIV2         (0x2C)
> > > +#define NPCM8XX_CLKDIV3         (0x58)
> > > +#define NPCM8XX_CLKDIV4         (0x7C)
> > > +#define NPCM8XX_PLLCON0         (0x0C)
> > > +#define NPCM8XX_PLLCON1         (0x10)
> > > +#define NPCM8XX_PLLCON2         (0x54)
> > > +#define NPCM8XX_SWRSTR          (0x14)
> > > +#define NPCM8XX_IRQWAKECON      (0x18)
> > > +#define NPCM8XX_IRQWAKEFLAG     (0x1C)
> > > +#define NPCM8XX_IPSRST1         (0x20)
> > > +#define NPCM8XX_IPSRST2         (0x24)
> > > +#define NPCM8XX_IPSRST3         (0x34)
> > > +#define NPCM8XX_WD0RCR          (0x38)
> > > +#define NPCM8XX_WD1RCR          (0x3C)
> > > +#define NPCM8XX_WD2RCR          (0x40)
> > > +#define NPCM8XX_SWRSTC1         (0x44)
> > > +#define NPCM8XX_SWRSTC2         (0x48)
> > > +#define NPCM8XX_SWRSTC3         (0x4C)
> > > +#define NPCM8XX_SWRSTC4         (0x50)
> > > +#define NPCM8XX_CORSTC          (0x5C)
> > > +#define NPCM8XX_PLLCONG         (0x60)
> > > +#define NPCM8XX_AHBCKFI         (0x64)
> > > +#define NPCM8XX_SECCNT          (0x68)
> > > +#define NPCM8XX_CNTR25M         (0x6C)
> > > +#define NPCM8XX_THRTL_CNT       (0xC0)
> > > +
> > > +struct npcm8xx_clk_mux_data {
> > > +       u8 shift;
> > > +       u8 mask;
> > > +       u32 *table;
> > > +       const char *name;
> > > +       const char * const *parent_names;
> > > +       u8 num_parents;
> > > +       unsigned long flags;
> > > +       /*
> > > +        * If this clock is exported via DT, set onecell_idx to constant
> > > +        * defined in include/dt-bindings/clock/nuvoton, NPCM8XX-clock.h for
> > > +        * this specific clock.  Otherwise, set to -1.
> > > +        */
> > > +       int onecell_idx;
> > > +};
> > > +
> > > +struct npcm8xx_clk_div_data {
> > > +       u32 reg;
> > > +       u8 shift;
> > > +       u8 width;
> > > +       const char *name;
> > > +       const char *parent_name;
> > > +       u8 clk_divider_flags;
> > > +       unsigned long flags;
> > > +       /*
> > > +        * If this clock is exported via DT, set onecell_idx to constant
> > > +        * defined in include/dt-bindings/clock/nuvoton, NPCM8XX-clock.h for
> > > +        * this specific clock.  Otherwise, set to -1.
> > > +        */
> > > +       int onecell_idx;
> > > +};
> > > +
> > > +struct npcm8xx_clk_pll_data {
> > > +       u32 reg;
> > > +       const char *name;
> > > +       const char *parent_name;
> >
> > Any reason why we're not using clk_parent_data or direct clk_hw
> > pointers?
> For more historical reasons, I did the same method as done in the
> NPCM7XX driver.
> The clk_init_data struct can use * const *parent_names,
> https://elixir.bootlin.com/linux/v5.19-rc6/source/include/linux/clk-provider.h#L289
> Is it problematic?
> >
> > > +       unsigned long flags;
> > > +       /*
> > > +        * If this clock is exported via DT, set onecell_idx to constant
> > > +        * defined in include/dt-bindings/clock/nuvoton, NPCM8XX-clock.h for
> > > +        * this specific clock.  Otherwise, set to -1.
> > > +        */
> > > +       int onecell_idx;
> > > +};
> > > +
> > > +/*
> > > + * Single copy of strings used to refer to clocks within this driver indexed by
> > > + * above enum.
> > > + */
> > > +#define NPCM8XX_CLK_S_REFCLK      "refclk"
> > > +#define NPCM8XX_CLK_S_SYSBYPCK    "sysbypck"
> > > +#define NPCM8XX_CLK_S_MCBYPCK     "mcbypck"
> > > +#define NPCM8XX_CLK_S_PLL0        "pll0"
> > > +#define NPCM8XX_CLK_S_PLL1        "pll1"
> > > +#define NPCM8XX_CLK_S_PLL1_DIV2   "pll1_div2"
> > > +#define NPCM8XX_CLK_S_PLL2        "pll2"
> > > +#define NPCM8XX_CLK_S_PLL_GFX     "pll_gfx"
> > > +#define NPCM8XX_CLK_S_PLL2_DIV2   "pll2_div2"
> > > +#define NPCM8XX_CLK_S_PIX_MUX     "gfx_pixel"
> > > +#define NPCM8XX_CLK_S_MC_MUX      "mc_phy"
> > > +#define NPCM8XX_CLK_S_CPU_MUX     "cpu"  /* AKA system clock */
> > > +#define NPCM8XX_CLK_S_MC          "mc"
> > > +#define NPCM8XX_CLK_S_AXI         "axi"  /* AKA CLK2 */
> > > +#define NPCM8XX_CLK_S_AHB         "ahb"  /* AKA CLK4 */
> > > +#define NPCM8XX_CLK_S_CLKOUT_MUX  "clkout_mux"
> > > +#define NPCM8XX_CLK_S_UART_MUX    "uart_mux"
> > > +#define NPCM8XX_CLK_S_SD_MUX      "sd_mux"
> > > +#define NPCM8XX_CLK_S_GFXM_MUX    "gfxm_mux"
> > > +#define NPCM8XX_CLK_S_SU_MUX      "serial_usb_mux"
> > > +#define NPCM8XX_CLK_S_DVC_MUX     "dvc_mux"
> > > +#define NPCM8XX_CLK_S_GFX_MUX     "gfx_mux"
> > > +#define NPCM8XX_CLK_S_ADC_MUX     "adc_mux"
> > > +#define NPCM8XX_CLK_S_SPI0        "spi0"
> > > +#define NPCM8XX_CLK_S_SPI1        "spi1"
> > > +#define NPCM8XX_CLK_S_SPI3        "spi3"
> > > +#define NPCM8XX_CLK_S_SPIX        "spix"
> > > +#define NPCM8XX_CLK_S_APB1        "apb1"
> > > +#define NPCM8XX_CLK_S_APB2        "apb2"
> > > +#define NPCM8XX_CLK_S_APB3        "apb3"
> > > +#define NPCM8XX_CLK_S_APB4        "apb4"
> > > +#define NPCM8XX_CLK_S_APB5        "apb5"
> > > +#define NPCM8XX_CLK_S_APB19       "apb19"
> > > +#define NPCM8XX_CLK_S_TOCK        "tock"
> > > +#define NPCM8XX_CLK_S_CLKOUT      "clkout"
> > > +#define NPCM8XX_CLK_S_PRE_ADC     "pre adc"
> > > +#define NPCM8XX_CLK_S_UART        "uart"
> > > +#define NPCM8XX_CLK_S_UART2       "uart2"
> > > +#define NPCM8XX_CLK_S_TIMER       "timer"
> > > +#define NPCM8XX_CLK_S_MMC         "mmc"
> > > +#define NPCM8XX_CLK_S_SDHC        "sdhc"
> > > +#define NPCM8XX_CLK_S_ADC         "adc"
> > > +#define NPCM8XX_CLK_S_GFX         "gfx0_gfx1_mem"
> > > +#define NPCM8XX_CLK_S_USBIF       "serial_usbif"
> > > +#define NPCM8XX_CLK_S_USB_HOST    "usb_host"
> > > +#define NPCM8XX_CLK_S_USB_BRIDGE  "usb_bridge"
> > > +#define NPCM8XX_CLK_S_PCI         "pci"
> > > +#define NPCM8XX_CLK_S_TH          "th"
> > > +#define NPCM8XX_CLK_S_ATB         "atb"
> > > +#define NPCM8XX_CLK_S_PRE_CLK     "pre_clk"
> > > +
> > > +#define NPCM8XX_CLK_S_RG_MUX     "rg_mux"
> > > +#define NPCM8XX_CLK_S_RCP_MUX    "rcp_mux"
> > > +#define NPCM8XX_CLK_S_RG         "rg"
> > > +#define NPCM8XX_CLK_S_RCP        "rcp"
> > > +
> > > +static u32 pll_mux_table[] = {0, 1, 2, 3};
> > > +static const char * const pll_mux_parents[] = {
> > > +       NPCM8XX_CLK_S_PLL0,
> > > +       NPCM8XX_CLK_S_PLL1,
> > > +       NPCM8XX_CLK_S_REFCLK,
> > > +       NPCM8XX_CLK_S_PLL2_DIV2,
> > > +};
> > > +
> > > +static u32 cpuck_mux_table[] = {0, 1, 2, 3, 7};
> > > +static const char * const cpuck_mux_parents[] = {
> > > +       NPCM8XX_CLK_S_PLL0,
> > > +       NPCM8XX_CLK_S_PLL1,
> > > +       NPCM8XX_CLK_S_REFCLK,
> > > +       NPCM8XX_CLK_S_SYSBYPCK,
> > > +       NPCM8XX_CLK_S_PLL2,
> > > +};
> > > +
> > > +static u32 pixcksel_mux_table[] = {0, 2};
> > > +static const char * const pixcksel_mux_parents[] = {
> > > +       NPCM8XX_CLK_S_PLL_GFX,
> > > +       NPCM8XX_CLK_S_REFCLK,
> > > +};
> > > +
> > > +static u32 sucksel_mux_table[] = {2, 3};
> > > +static const char * const sucksel_mux_parents[] = {
> > > +       NPCM8XX_CLK_S_REFCLK,
> > > +       NPCM8XX_CLK_S_PLL2_DIV2,
> > > +};
> > > +
> > > +static u32 mccksel_mux_table[] = {0, 2, 3};
> > > +static const char * const mccksel_mux_parents[] = {
> > > +       NPCM8XX_CLK_S_PLL1_DIV2,
> > > +       NPCM8XX_CLK_S_REFCLK,
> > > +       NPCM8XX_CLK_S_MCBYPCK,
> > > +};
> > > +
> > > +static u32 clkoutsel_mux_table[] = {0, 1, 2, 3, 4};
> > > +static const char * const clkoutsel_mux_parents[] = {
> > > +       NPCM8XX_CLK_S_PLL0,
> > > +       NPCM8XX_CLK_S_PLL1,
> > > +       NPCM8XX_CLK_S_REFCLK,
> > > +       NPCM8XX_CLK_S_PLL_GFX, // divided by 2
> > > +       NPCM8XX_CLK_S_PLL2_DIV2,
> > > +};
> > > +
> > > +static u32 gfxmsel_mux_table[] = {2, 3};
> > > +static const char * const gfxmsel_mux_parents[] = {
> > > +       NPCM8XX_CLK_S_REFCLK,
> > > +       NPCM8XX_CLK_S_PLL2_DIV2,
> > > +};
> > > +
> > > +static u32 dvcssel_mux_table[] = {2, 3};
> > > +static const char * const dvcssel_mux_parents[] = {
> > > +       NPCM8XX_CLK_S_REFCLK,
> > > +       NPCM8XX_CLK_S_PLL2,
> > > +};
> > > +
> > > +static const struct npcm8xx_clk_pll_data npcm8xx_plls[] = {
> > > +       {NPCM8XX_PLLCON0, NPCM8XX_CLK_S_PLL0, NPCM8XX_CLK_S_REFCLK, 0, -1},
> > > +       {NPCM8XX_PLLCON1, NPCM8XX_CLK_S_PLL1, NPCM8XX_CLK_S_REFCLK, 0, -1},
> > > +       {NPCM8XX_PLLCON2, NPCM8XX_CLK_S_PLL2, NPCM8XX_CLK_S_REFCLK, 0, -1},
> > > +       {NPCM8XX_PLLCONG, NPCM8XX_CLK_S_PLL_GFX, NPCM8XX_CLK_S_REFCLK, 0, -1},
> > > +};
> > > +
> > > +static const struct npcm8xx_clk_mux_data npcm8xx_muxes[] = {
> > > +       {0, GENMASK(1, 0), cpuck_mux_table, NPCM8XX_CLK_S_CPU_MUX,
> > > +       cpuck_mux_parents, ARRAY_SIZE(cpuck_mux_parents), CLK_IS_CRITICAL,
> > > +       NPCM8XX_CLK_CPU},
> > > +
> > > +       {4, GENMASK(1, 0), pixcksel_mux_table, NPCM8XX_CLK_S_PIX_MUX,
> > > +       pixcksel_mux_parents, ARRAY_SIZE(pixcksel_mux_parents), 0,
> > > +       NPCM8XX_CLK_GFX_PIXEL},
> > > +
> > > +       {6, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_SD_MUX,
> > > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > > +
> > > +       {8, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_UART_MUX,
> > > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > > +
> > > +       {10, GENMASK(1, 0), sucksel_mux_table, NPCM8XX_CLK_S_SU_MUX,
> > > +       sucksel_mux_parents, ARRAY_SIZE(sucksel_mux_parents), 0, -1},
> > > +
> > > +       {12, GENMASK(1, 0), mccksel_mux_table, NPCM8XX_CLK_S_MC_MUX,
> > > +       mccksel_mux_parents, ARRAY_SIZE(mccksel_mux_parents), 0, -1},
> > > +
> > > +       {14, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_ADC_MUX,
> > > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > > +
> > > +       {16, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_GFX_MUX,
> > > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > > +
> > > +       {18, GENMASK(2, 0), clkoutsel_mux_table, NPCM8XX_CLK_S_CLKOUT_MUX,
> > > +       clkoutsel_mux_parents, ARRAY_SIZE(clkoutsel_mux_parents), 0, -1},
> > > +
> > > +       {21, GENMASK(1, 0), gfxmsel_mux_table, NPCM8XX_CLK_S_GFXM_MUX,
> > > +       gfxmsel_mux_parents, ARRAY_SIZE(gfxmsel_mux_parents), 0, -1},
> > > +
> > > +       {23, GENMASK(1, 0), dvcssel_mux_table, NPCM8XX_CLK_S_DVC_MUX,
> > > +       dvcssel_mux_parents, ARRAY_SIZE(dvcssel_mux_parents), 0, -1},
> > > +
> > > +       {25, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_RG_MUX,
> > > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > > +
> > > +       {27, GENMASK(1, 0), pll_mux_table, NPCM8XX_CLK_S_RCP_MUX,
> > > +       pll_mux_parents, ARRAY_SIZE(pll_mux_parents), 0, -1},
> > > +};
> > > +
> > > +/* configurable dividers: */
> > > +static const struct npcm8xx_clk_div_data npcm8xx_divs[] = {
> > > +       {NPCM8XX_CLKDIV1, 28, 3, NPCM8XX_CLK_S_ADC, NPCM8XX_CLK_S_PRE_ADC,
> > > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > > +               NPCM8XX_CLK_ADC},
> > > +       /* bit 30-28 ADCCKDIV*/
> > > +       {NPCM8XX_CLKDIV1, 26, 2, NPCM8XX_CLK_S_AHB, NPCM8XX_CLK_S_PRE_CLK,
> > > +               CLK_DIVIDER_READ_ONLY, CLK_IS_CRITICAL, NPCM8XX_CLK_AHB},
> > > +       /* bit 28-26 CLK4DIV*/
> > > +       {NPCM8XX_CLKDIV1, 21, 5, NPCM8XX_CLK_S_PRE_ADC,
> > > +       NPCM8XX_CLK_S_ADC_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_PRE_ADC},
> > > +       /* bit 25-21 PRE-ADCCKDIV*/
> > > +       {NPCM8XX_CLKDIV1, 16, 5, NPCM8XX_CLK_S_UART,
> > > +       NPCM8XX_CLK_S_UART_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_UART},
> > > +       /* bit 20-16 UARTDIV*/
> > > +       {NPCM8XX_CLKDIV1, 11, 5, NPCM8XX_CLK_S_MMC,
> > > +       NPCM8XX_CLK_S_SD_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_MMC},
> > > +       /* bit 15-11 MMCCKDIV*/
> > > +       {NPCM8XX_CLKDIV1, 6, 5, NPCM8XX_CLK_S_SPI3,
> > > +       NPCM8XX_CLK_S_AHB, 0, 0, NPCM8XX_CLK_SPI3},
> > > +       /* bit 10-6 AHB3CKDIV*/
> > > +       {NPCM8XX_CLKDIV1, 2, 4, NPCM8XX_CLK_S_PCI,
> > > +       NPCM8XX_CLK_S_GFX_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_PCI},
> > > +       /* bit 5-2 PCICKDIV*/
> > > +
> > > +       {NPCM8XX_CLKDIV2, 30, 2, NPCM8XX_CLK_S_APB4, NPCM8XX_CLK_S_AHB,
> > > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > > +               NPCM8XX_CLK_APB4},
> > > +       /* bit 31-30 APB4CKDIV*/
> > > +       {NPCM8XX_CLKDIV2, 28, 2, NPCM8XX_CLK_S_APB3, NPCM8XX_CLK_S_AHB,
> > > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > > +               NPCM8XX_CLK_APB3},
> > > +       /* bit 29-28 APB3CKDIV*/
> > > +       {NPCM8XX_CLKDIV2, 26, 2, NPCM8XX_CLK_S_APB2, NPCM8XX_CLK_S_AHB,
> > > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > > +               NPCM8XX_CLK_APB2},
> > > +       /* bit 28-26 APB2CKDIV*/
> > > +       {NPCM8XX_CLKDIV2, 24, 2, NPCM8XX_CLK_S_APB1, NPCM8XX_CLK_S_AHB,
> > > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > > +               NPCM8XX_CLK_APB1},
> > > +       /* bit 25-24 APB1CKDIV*/
> > > +       {NPCM8XX_CLKDIV2, 22, 2, NPCM8XX_CLK_S_APB5, NPCM8XX_CLK_S_AHB,
> > > +               CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0,
> > > +               NPCM8XX_CLK_APB5},
> > > +       /* bit 23-22 APB5CKDIV*/
> > > +       {NPCM8XX_CLKDIV2, 16, 5, NPCM8XX_CLK_S_CLKOUT, NPCM8XX_CLK_S_CLKOUT_MUX,
> > > +                CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_CLKOUT},
> > > +       /* bit 20-16 CLKOUTDIV*/
> > > +       {NPCM8XX_CLKDIV2, 13, 3, NPCM8XX_CLK_S_GFX, NPCM8XX_CLK_S_GFX_MUX,
> > > +               CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_GFX},
> > > +       /* bit 15-13 GFXCKDIV*/
> > > +       {NPCM8XX_CLKDIV2, 8, 5, NPCM8XX_CLK_S_USB_BRIDGE, NPCM8XX_CLK_S_SU_MUX,
> > > +               CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SU},
> > > +       /* bit 12-8 SUCKDIV*/
> > > +       {NPCM8XX_CLKDIV2, 4, 4, NPCM8XX_CLK_S_USB_HOST, NPCM8XX_CLK_S_SU_MUX,
> > > +               CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SU48},
> > > +       /* bit 8-4 SU48CKDIV*/
> > > +       {NPCM8XX_CLKDIV2, 0, 4, NPCM8XX_CLK_S_SDHC,
> > > +       NPCM8XX_CLK_S_SD_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SDHC}
> > > +       ,/* bit 3-0 SD1CKDIV*/
> > > +
> > > +       {NPCM8XX_CLKDIV3, 16, 8, NPCM8XX_CLK_S_SPI1,
> > > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPI1},
> > > +       /* bit 23-16 SPI1CKDV*/
> > > +       {NPCM8XX_CLKDIV3, 11, 5, NPCM8XX_CLK_S_UART2,
> > > +       NPCM8XX_CLK_S_UART_MUX, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_UART2},
> > > +       /* bit 15-11 UARTDIV2*/
> > > +       {NPCM8XX_CLKDIV3, 6, 5, NPCM8XX_CLK_S_SPI0,
> >
> > Please run checkpatch, add a space after '{' and before '}'
> I did run checkpatch, it weird I didn't got a warning about it.
> will be fixed.
> >
> > > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPI0},
> > > +       /* bit 10-6 SPI0CKDV*/
> > > +       {NPCM8XX_CLKDIV3, 1, 5, NPCM8XX_CLK_S_SPIX,
> > > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPIX},
> > > +       /* bit 5-1 SPIXCKDV*/
> > > +
> > > +       {NPCM8XX_CLKDIV4, 28, 4, NPCM8XX_CLK_S_RG, NPCM8XX_CLK_S_RG_MUX,
> > > +       CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_RG},
> > > +       /* bit 31-28 RGREFDIV*/
> > > +       {NPCM8XX_CLKDIV4, 12, 4, NPCM8XX_CLK_S_RCP, NPCM8XX_CLK_S_RCP_MUX,
> > > +       CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_RCP},
> > > +       /* bit 15-12 RCPREFDIV*/
> > > +       {NPCM8XX_THRTL_CNT, 0, 2, NPCM8XX_CLK_S_TH, NPCM8XX_CLK_S_CPU_MUX,
> > > +       CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0, NPCM8XX_CLK_TH},
> > > +       /* bit 1-0 TH_DIV*/
> > > +};
> > > +
> > > +static DEFINE_SPINLOCK(npcm8xx_clk_lock);
> > > +
> > > +static int npcm8xx_clk_probe(struct platform_device *pdev)
> > > +{
> > > +       struct clk_hw_onecell_data *npcm8xx_clk_data;
> > > +       struct device *dev = &pdev->dev;
> > > +       struct device_node *np = dev->of_node;
> > > +       void __iomem *clk_base;
> > > +       struct resource res;
> > > +       struct clk_hw *hw;
> > > +       int i, err;
> > > +
> > > +       npcm8xx_clk_data = devm_kzalloc(dev, struct_size(npcm8xx_clk_data, hws,
> > > +                                                        NPCM8XX_NUM_CLOCKS),
> > > +                                       GFP_KERNEL);
> > > +       if (!npcm8xx_clk_data)
> > > +               return -ENOMEM;
> > > +
> > > +       err = of_address_to_resource(np, 0, &res);
> >
> > Why can't we use platform_get_resource()?
> >
> > > +       if (err) {
> > > +               dev_err(dev, "Failed to get resource, ret %d\n", err);
> > > +               return err;
> > > +       }
> > > +
> > > +       clk_base = ioremap(res.start, resource_size(&res));
> >
> > And use devm_platform_ioremap_resource()?
> Clock and reset driver use the same memory register map 0xF0801000 - 0xF0801FFF.
> For historical reasons the registers of both modules are mixed in the
> memory range 0xF0801000 - 0xF0801FFF this is why we can't have a
> separate region for each module.
> In case I will use devm_platform_ioremap_resource function the reset
> ioremap will fail so the driver using the method above.
> >
> > > +       if (!clk_base) {
> > > +               dev_err(&pdev->dev, "Failed to remap I/O memory\n");
> > > +               return -ENOMEM;
> > > +       }
> > > +
> > > +       npcm8xx_clk_data->num = NPCM8XX_NUM_CLOCKS;
> > > +
> > > +       for (i = 0; i < NPCM8XX_NUM_CLOCKS; i++)
> > > +               npcm8xx_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
> > > +
> > > +       /* Reference 25MHz clock */
> >
> > Does this exist on the board? If so, I'd make a fixed rate clk in the
> > dts and have 'refclk' be an input in the binding for this clk controller.
> No, it is an internal clock in the SoC, this is why it is in the driver.
> >
> > > +       hw = clk_hw_register_fixed_rate(dev, "refclk", NULL, 0, NPCM8XX_REF_CLK);
> > > +       if (IS_ERR(hw))
> > > +               return PTR_ERR(hw);
> > > +       npcm8xx_clk_data->hws[NPCM8XX_CLK_REFCLK] = hw;
> > > +
> > > +       /* Register plls */
> > > +       for (i = 0; i < ARRAY_SIZE(npcm8xx_plls); i++) {
> > > +               const struct npcm8xx_clk_pll_data *pll_data = &npcm8xx_plls[i];
> > > +
> > > +               hw = npcm8xx_clk_register_pll(dev, clk_base + pll_data->reg,
> > > +                                             pll_data->name,
> > > +                                             pll_data->parent_name,
> > > +                                             pll_data->flags);
> > > +               if (IS_ERR(hw)) {
> > > +                       dev_err(dev, "npcm8xx_clk: Can't register pll\n");
> > > +                       goto unregister_refclk;
> > > +               }
> > > +
> > > +               if (pll_data->onecell_idx >= 0)
> > > +                       npcm8xx_clk_data->hws[pll_data->onecell_idx] = hw;
> > > +       }
> > > +
> > > +       /* Register fixed dividers */
> > > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_PLL1_DIV2,
> > > +                                              NPCM8XX_CLK_S_PLL1, 0, 1, 2);
> > > +       if (IS_ERR(hw)) {
> > > +               dev_err(dev, "npcm8xx_clk: Can't register fixed div\n");
> > > +               goto unregister_refclk;
> > > +       }
> > > +
> > > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_PLL2_DIV2,
> > > +                                              NPCM8XX_CLK_S_PLL2, 0, 1, 2);
> > > +       if (IS_ERR(hw)) {
> > > +               dev_err(dev, "npcm8xx_clk: Can't register pll div2\n");
> > > +               goto unregister_refclk;
> > > +       }
> > > +
> > > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_PRE_CLK,
> > > +                                              NPCM8XX_CLK_S_CPU_MUX, 0, 1, 2);
> > > +       if (IS_ERR(hw)) {
> > > +               dev_err(dev, "npcm8xx_clk: Can't register ckclk div2\n");
> > > +               goto unregister_refclk;
> > > +       }
> > > +
> > > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_AXI,
> > > +                                              NPCM8XX_CLK_S_TH, 0, 1, 2);
> > > +       if (IS_ERR(hw)) {
> > > +               dev_err(dev, "npcm8xx_clk: Can't register axi div2\n");
> > > +               goto unregister_refclk;
> > > +       }
> > > +
> > > +       hw = devm_clk_hw_register_fixed_factor(dev, NPCM8XX_CLK_S_ATB,
> > > +                                              NPCM8XX_CLK_S_AXI, 0, 1, 2);
> > > +       if (IS_ERR(hw)) {
> > > +               dev_err(dev, "npcm8xx_clk: Can't register atb div2\n");
> > > +               goto unregister_refclk;
> > > +       }
> > > +
> > > +       /* Register clock dividers specified in npcm8xx_divs */
> > > +       for (i = 0; i < ARRAY_SIZE(npcm8xx_divs); i++) {
> > > +               const struct npcm8xx_clk_div_data *div_data = &npcm8xx_divs[i];
> > > +
> > > +               hw = devm_clk_hw_register_divider(dev, div_data->name,
> > > +                                                 div_data->parent_name,
> > > +                                                 div_data->flags,
> > > +                                                 clk_base + div_data->reg,
> > > +                                                 div_data->shift,
> > > +                                                 div_data->width,
> > > +                                                 div_data->clk_divider_flags,
> > > +                                                 &npcm8xx_clk_lock);
> > > +               if (IS_ERR(hw)) {
> > > +                       dev_err(dev, "npcm8xx_clk: Can't register div table\n");
> > > +                       goto unregister_refclk;
> > > +               }
> > > +
> > > +               if (div_data->onecell_idx >= 0)
> > > +                       npcm8xx_clk_data->hws[div_data->onecell_idx] = hw;
> > > +       }
> > > +
> > > +       /* Register muxes */
> > > +       for (i = 0; i < ARRAY_SIZE(npcm8xx_muxes); i++) {
> > > +               const struct npcm8xx_clk_mux_data *mux_data = &npcm8xx_muxes[i];
> > > +
> > > +               hw = clk_hw_register_mux_table(dev, mux_data->name,
> > > +                                              mux_data->parent_names,
> > > +                                              mux_data->num_parents,
> > > +                                              mux_data->flags,
> > > +                                              clk_base + NPCM8XX_CLKSEL,
> > > +                                              mux_data->shift,
> > > +                                              mux_data->mask, 0,
> > > +                                              mux_data->table,
> > > +                                              &npcm8xx_clk_lock);
> > > +
> > > +               if (IS_ERR(hw)) {
> > > +                       dev_err(dev, "npcm8xx_clk: Can't register mux\n");
> > > +                       goto err_mux_clk;
> > > +               }
> > > +
> > > +               if (mux_data->onecell_idx >= 0)
> > > +                       npcm8xx_clk_data->hws[mux_data->onecell_idx] = hw;
> > > +       }
> > > +
> > > +       err = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
> > > +                                         npcm8xx_clk_data);
> > > +       if (err) {
> > > +               dev_err(dev, "unable to add clk provider\n");
> > > +               goto unregister_refclk;
> >
> > The 'hw' pointer doesn't contain 'err' here so probe will return some
> > positive number when this fails?
> Indeed, will be fixed.
> >
> > > +       }
> > > +
> > > +       return err;
> > > +
> > > +err_mux_clk:
> > > +       while (i--) {
> > > +               if (npcm8xx_muxes[i].onecell_idx >= 0)
> > > +                       clk_hw_unregister_mux(npcm8xx_clk_data->hws[npcm8xx_muxes[i].onecell_idx]);
> > > +       }
> > > +unregister_refclk:
> > > +       clk_hw_unregister(npcm8xx_clk_data->hws[NPCM8XX_CLK_REFCLK]);
> > > +       return PTR_ERR(hw);
> > > +}
> > > +
> > > +static const struct of_device_id npcm8xx_clk_dt_ids[] = {
> > > +       { .compatible = "nuvoton,npcm845-clk", },
> > > +       { }
> > > +};
> > > +MODULE_DEVICE_TABLE(of, npcm8xx_clk_dt_ids);
> > > +
> > > +static struct platform_driver npcm8xx_clk_driver = {
> > > +       .probe  = npcm8xx_clk_probe,
> > > +       .driver = {
> > > +               .name = "npcm8xx_clk",
> > > +               .of_match_table = npcm8xx_clk_dt_ids,
> > > +       },
> > > +};
> > > +
> > > +static int __init npcm8xx_clk_driver_init(void)
> > > +{
> > > +       return platform_driver_register(&npcm8xx_clk_driver);
> > > +}
> > > +arch_initcall(npcm8xx_clk_driver_init);
> > > +
> >
> > If it can be a module it needs to unregister the driver on module exit.
> Will remove the MODULE_DEVICE_TABLE, the driver clock should be a
> built-in kernel driver.
>
> Thanks,
>
> Tomer

Thanks a lot,

Tomer
Stephen Boyd July 18, 2022, 7:14 p.m. UTC | #3
Quoting Tomer Maimon (2022-07-12 00:28:30)
> On Mon, 11 Jul 2022 at 22:55, Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Tomer Maimon (2022-07-11 05:35:07)
> > > +        */
> > > +       int onecell_idx;
> > > +};
> > > +
> > > +struct npcm8xx_clk_pll_data {
> > > +       u32 reg;
> > > +       const char *name;
> > > +       const char *parent_name;
> >
> > Any reason why we're not using clk_parent_data or direct clk_hw
> > pointers?
> For more historical reasons, I did the same method as done in the
> NPCM7XX driver.
> The clk_init_data struct can use * const *parent_names,
> https://elixir.bootlin.com/linux/v5.19-rc6/source/include/linux/clk-provider.h#L289
> Is it problematic?

It will need to be changed to not use global string matching. Ideally
new drivers use clk_parent_data or clk_hw pointers directly. It's faster
and preferred.

> >
> > > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPI0},
> > > +       /* bit 10-6 SPI0CKDV*/
> > > +       {NPCM8XX_CLKDIV3, 1, 5, NPCM8XX_CLK_S_SPIX,
> > > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPIX},
> > > +       /* bit 5-1 SPIXCKDV*/
> > > +
> > > +       {NPCM8XX_CLKDIV4, 28, 4, NPCM8XX_CLK_S_RG, NPCM8XX_CLK_S_RG_MUX,
> > > +       CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_RG},
> > > +       /* bit 31-28 RGREFDIV*/
> > > +       {NPCM8XX_CLKDIV4, 12, 4, NPCM8XX_CLK_S_RCP, NPCM8XX_CLK_S_RCP_MUX,
> > > +       CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_RCP},
> > > +       /* bit 15-12 RCPREFDIV*/
> > > +       {NPCM8XX_THRTL_CNT, 0, 2, NPCM8XX_CLK_S_TH, NPCM8XX_CLK_S_CPU_MUX,
> > > +       CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0, NPCM8XX_CLK_TH},
> > > +       /* bit 1-0 TH_DIV*/
> > > +};
> > > +
> > > +static DEFINE_SPINLOCK(npcm8xx_clk_lock);
> > > +
> > > +static int npcm8xx_clk_probe(struct platform_device *pdev)
> > > +{
> > > +       struct clk_hw_onecell_data *npcm8xx_clk_data;
> > > +       struct device *dev = &pdev->dev;
> > > +       struct device_node *np = dev->of_node;
> > > +       void __iomem *clk_base;
> > > +       struct resource res;
> > > +       struct clk_hw *hw;
> > > +       int i, err;
> > > +
> > > +       npcm8xx_clk_data = devm_kzalloc(dev, struct_size(npcm8xx_clk_data, hws,
> > > +                                                        NPCM8XX_NUM_CLOCKS),
> > > +                                       GFP_KERNEL);
> > > +       if (!npcm8xx_clk_data)
> > > +               return -ENOMEM;
> > > +
> > > +       err = of_address_to_resource(np, 0, &res);
> >
> > Why can't we use platform_get_resource()?
> >
> > > +       if (err) {
> > > +               dev_err(dev, "Failed to get resource, ret %d\n", err);
> > > +               return err;
> > > +       }
> > > +
> > > +       clk_base = ioremap(res.start, resource_size(&res));
> >
> > And use devm_platform_ioremap_resource()?
> Clock and reset driver use the same memory register map 0xF0801000 - 0xF0801FFF.
> For historical reasons the registers of both modules are mixed in the
> memory range 0xF0801000 - 0xF0801FFF this is why we can't have a
> separate region for each module.
> In case I will use devm_platform_ioremap_resource function the reset
> ioremap will fail so the driver using the method above.

So the clk and reset driver should be the same driver, or one driver
should register the other and use the auxiliary bus to express the
relationship. That way we know that the drivers are tightly coupled and
aren't going to stomp over each other.

> >
> > > +       if (!clk_base) {
> > > +               dev_err(&pdev->dev, "Failed to remap I/O memory\n");
> > > +               return -ENOMEM;
> > > +       }
> > > +
> > > +       npcm8xx_clk_data->num = NPCM8XX_NUM_CLOCKS;
> > > +
> > > +       for (i = 0; i < NPCM8XX_NUM_CLOCKS; i++)
> > > +               npcm8xx_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
> > > +
> > > +       /* Reference 25MHz clock */
> >
> > Does this exist on the board? If so, I'd make a fixed rate clk in the
> > dts and have 'refclk' be an input in the binding for this clk controller.
> No, it is an internal clock in the SoC, this is why it is in the driver.

Ok. I suppose that could be inside the 'soc' node for this device as a
fixed rate clk but registering it here is also fine.
Tomer Maimon July 19, 2022, 10:04 a.m. UTC | #4
Hi Stephen,

Thanks for your reply.

On Mon, 18 Jul 2022 at 22:14, Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Tomer Maimon (2022-07-12 00:28:30)
> > On Mon, 11 Jul 2022 at 22:55, Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > Quoting Tomer Maimon (2022-07-11 05:35:07)
> > > > +        */
> > > > +       int onecell_idx;
> > > > +};
> > > > +
> > > > +struct npcm8xx_clk_pll_data {
> > > > +       u32 reg;
> > > > +       const char *name;
> > > > +       const char *parent_name;
> > >
> > > Any reason why we're not using clk_parent_data or direct clk_hw
> > > pointers?
> > For more historical reasons, I did the same method as done in the
> > NPCM7XX driver.
> > The clk_init_data struct can use * const *parent_names,
> > https://elixir.bootlin.com/linux/v5.19-rc6/source/include/linux/clk-provider.h#L289
> > Is it problematic?
>
> It will need to be changed to not use global string matching. Ideally
> new drivers use clk_parent_data or clk_hw pointers directly. It's faster
> and preferred.
Will be modified V10.
>
> > >
> > > > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPI0},
> > > > +       /* bit 10-6 SPI0CKDV*/
> > > > +       {NPCM8XX_CLKDIV3, 1, 5, NPCM8XX_CLK_S_SPIX,
> > > > +       NPCM8XX_CLK_S_AHB, CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_SPIX},
> > > > +       /* bit 5-1 SPIXCKDV*/
> > > > +
> > > > +       {NPCM8XX_CLKDIV4, 28, 4, NPCM8XX_CLK_S_RG, NPCM8XX_CLK_S_RG_MUX,
> > > > +       CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_RG},
> > > > +       /* bit 31-28 RGREFDIV*/
> > > > +       {NPCM8XX_CLKDIV4, 12, 4, NPCM8XX_CLK_S_RCP, NPCM8XX_CLK_S_RCP_MUX,
> > > > +       CLK_DIVIDER_READ_ONLY, 0, NPCM8XX_CLK_RCP},
> > > > +       /* bit 15-12 RCPREFDIV*/
> > > > +       {NPCM8XX_THRTL_CNT, 0, 2, NPCM8XX_CLK_S_TH, NPCM8XX_CLK_S_CPU_MUX,
> > > > +       CLK_DIVIDER_READ_ONLY | CLK_DIVIDER_POWER_OF_TWO, 0, NPCM8XX_CLK_TH},
> > > > +       /* bit 1-0 TH_DIV*/
> > > > +};
> > > > +
> > > > +static DEFINE_SPINLOCK(npcm8xx_clk_lock);
> > > > +
> > > > +static int npcm8xx_clk_probe(struct platform_device *pdev)
> > > > +{
> > > > +       struct clk_hw_onecell_data *npcm8xx_clk_data;
> > > > +       struct device *dev = &pdev->dev;
> > > > +       struct device_node *np = dev->of_node;
> > > > +       void __iomem *clk_base;
> > > > +       struct resource res;
> > > > +       struct clk_hw *hw;
> > > > +       int i, err;
> > > > +
> > > > +       npcm8xx_clk_data = devm_kzalloc(dev, struct_size(npcm8xx_clk_data, hws,
> > > > +                                                        NPCM8XX_NUM_CLOCKS),
> > > > +                                       GFP_KERNEL);
> > > > +       if (!npcm8xx_clk_data)
> > > > +               return -ENOMEM;
> > > > +
> > > > +       err = of_address_to_resource(np, 0, &res);
> > >
> > > Why can't we use platform_get_resource()?
> > >
> > > > +       if (err) {
> > > > +               dev_err(dev, "Failed to get resource, ret %d\n", err);
> > > > +               return err;
> > > > +       }
> > > > +
> > > > +       clk_base = ioremap(res.start, resource_size(&res));
> > >
> > > And use devm_platform_ioremap_resource()?
> > Clock and reset driver use the same memory register map 0xF0801000 - 0xF0801FFF.
> > For historical reasons the registers of both modules are mixed in the
> > memory range 0xF0801000 - 0xF0801FFF this is why we can't have a
> > separate region for each module.
> > In case I will use devm_platform_ioremap_resource function the reset
> > ioremap will fail so the driver using the method above.
>
> So the clk and reset driver should be the same driver, or one driver
> should register the other and use the auxiliary bus to express the
> relationship. That way we know that the drivers are tightly coupled and
> aren't going to stomp over each other.
I think it is very problematic to use the same driver for the reset
and the clocks also because The NPCM reset driver is an old driver
that was used also to the older NPCM BMC SoC so it will be problematic
to use the clock and reset driver in the same space.
indeed the reset and clocks are using the same memory region but they
are not using the same registers, is it not enough?
Please be aware that the NPCM reset driver is checking that it is
using the reset registers before calling I/O functions.
> > >
> > > > +       if (!clk_base) {
> > > > +               dev_err(&pdev->dev, "Failed to remap I/O memory\n");
> > > > +               return -ENOMEM;
> > > > +       }
> > > > +
> > > > +       npcm8xx_clk_data->num = NPCM8XX_NUM_CLOCKS;
> > > > +
> > > > +       for (i = 0; i < NPCM8XX_NUM_CLOCKS; i++)
> > > > +               npcm8xx_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
> > > > +
> > > > +       /* Reference 25MHz clock */
> > >
> > > Does this exist on the board? If so, I'd make a fixed rate clk in the
> > > dts and have 'refclk' be an input in the binding for this clk controller.
> > No, it is an internal clock in the SoC, this is why it is in the driver.
>
> Ok. I suppose that could be inside the 'soc' node for this device as a
> fixed rate clk but registering it here is also fine.

Best regards,

Tomer
Stephen Boyd July 23, 2022, 3:02 a.m. UTC | #5
Quoting Tomer Maimon (2022-07-19 03:04:43)
> On Mon, 18 Jul 2022 at 22:14, Stephen Boyd <sboyd@kernel.org> wrote:
> >
> >
> > So the clk and reset driver should be the same driver, or one driver
> > should register the other and use the auxiliary bus to express the
> > relationship. That way we know that the drivers are tightly coupled and
> > aren't going to stomp over each other.
> I think it is very problematic to use the same driver for the reset
> and the clocks also because The NPCM reset driver is an old driver
> that was used also to the older NPCM BMC SoC so it will be problematic
> to use the clock and reset driver in the same space.
> indeed the reset and clocks are using the same memory region but they
> are not using the same registers, is it not enough?
> Please be aware that the NPCM reset driver is checking that it is
> using the reset registers before calling I/O functions.

To put it simply, platform device drivers should use platform device
APIs. The platform device APIs hide the fact that the firmware is ACPI
or DT or nothing at all. The usage of of_address_to_resource() is
problematic.

After converting that to platform APIs you'll get janitor style cleanups
trying to convert to devm_platform_ioremap_resource(). We'll have to
discuss this again when that happens, even if there's a comment in the
code indicating we can't reserve the IO space because there's another
driver. These problems have happened in the past, fun times!

Furthermore, in DT, reg properties aren't supposed to overlap. When that
happens it usually indicates the DT is being written to describe driver
structure instead of the IP blocks that are delivered by the hardware
engineer. In this case it sounds like a combined clk and reset IP block
because they piled all the SoC glue stuff into a register range. Are
there more features in this IO range?
Tomer Maimon July 24, 2022, 9:06 a.m. UTC | #6
Hi Stephen,

Thanks for your detailed explanation!

On Sat, 23 Jul 2022 at 06:02, Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Tomer Maimon (2022-07-19 03:04:43)
> > On Mon, 18 Jul 2022 at 22:14, Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > >
> > > So the clk and reset driver should be the same driver, or one driver
> > > should register the other and use the auxiliary bus to express the
> > > relationship. That way we know that the drivers are tightly coupled and
> > > aren't going to stomp over each other.
> > I think it is very problematic to use the same driver for the reset
> > and the clocks also because The NPCM reset driver is an old driver
> > that was used also to the older NPCM BMC SoC so it will be problematic
> > to use the clock and reset driver in the same space.
> > indeed the reset and clocks are using the same memory region but they
> > are not using the same registers, is it not enough?
> > Please be aware that the NPCM reset driver is checking that it is
> > using the reset registers before calling I/O functions.
>
> To put it simply, platform device drivers should use platform device
> APIs. The platform device APIs hide the fact that the firmware is ACPI
> or DT or nothing at all. The usage of of_address_to_resource() is
> problematic.
>
> After converting that to platform APIs you'll get janitor style cleanups
> trying to convert to devm_platform_ioremap_resource(). We'll have to
> discuss this again when that happens, even if there's a comment in the
> code indicating we can't reserve the IO space because there's another
> driver. These problems have happened in the past, fun times!
>
> Furthermore, in DT, reg properties aren't supposed to overlap. When that
> happens it usually indicates the DT is being written to describe driver
> structure instead of the IP blocks that are delivered by the hardware
> engineer. In this case it sounds like a combined clk and reset IP block
> because they piled all the SoC glue stuff into a register range. Are
> there more features in this IO range?

No, this range only combined the reset and clock together, but it
combined in a way that we cannot split it to two or even three
different registers...

I do see a way to combine the clock and the reset driver, the NPCM
reset driver is serving other NPCM BMC's.
Should we use regmap to handle the clock registers instead of ioremap?

Best regards,

Tomer
Stephen Boyd July 29, 2022, 10:56 p.m. UTC | #7
Quoting Tomer Maimon (2022-07-24 02:06:54)
> On Sat, 23 Jul 2022 at 06:02, Stephen Boyd <sboyd@kernel.org> wrote:
> > Furthermore, in DT, reg properties aren't supposed to overlap. When that
> > happens it usually indicates the DT is being written to describe driver
> > structure instead of the IP blocks that are delivered by the hardware
> > engineer. In this case it sounds like a combined clk and reset IP block
> > because they piled all the SoC glue stuff into a register range. Are
> > there more features in this IO range?
> 
> No, this range only combined the reset and clock together, but it
> combined in a way that we cannot split it to two or even three
> different registers...

Because it is jumbled in some range?

> 
> I do see a way to combine the clock and the reset driver, the NPCM
> reset driver is serving other NPCM BMC's.
> Should we use regmap to handle the clock registers instead of ioremap?

Sure? Using regmap or not looks like a parallel discussion. How does it
help use platform APIs?
Tomer Maimon Aug. 4, 2022, 2:01 p.m. UTC | #8
On Sat, 30 Jul 2022 at 01:56, Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Tomer Maimon (2022-07-24 02:06:54)
> > On Sat, 23 Jul 2022 at 06:02, Stephen Boyd <sboyd@kernel.org> wrote:
> > > Furthermore, in DT, reg properties aren't supposed to overlap. When that
> > > happens it usually indicates the DT is being written to describe driver
> > > structure instead of the IP blocks that are delivered by the hardware
> > > engineer. In this case it sounds like a combined clk and reset IP block
> > > because they piled all the SoC glue stuff into a register range. Are
> > > there more features in this IO range?
> >
> > No, this range only combined the reset and clock together, but it
> > combined in a way that we cannot split it to two or even three
> > different registers...
>
> Because it is jumbled in some range?
Yes.
>
> >
> > I do see a way to combine the clock and the reset driver, the NPCM
> > reset driver is serving other NPCM BMC's.
> > Should we use regmap to handle the clock registers instead of ioremap?
>
> Sure? Using regmap or not looks like a parallel discussion. How does it
> help use platform APIs?
I mean to use regmap API instead of platform API for handing the clock
and reset registers.
the regmap API gives only one user access to R/W (lock).
I will be happy to get more suggestions, on how should we solve this situation.

Thanks,

Tomer
Stephen Boyd Aug. 4, 2022, 8:05 p.m. UTC | #9
Quoting Tomer Maimon (2022-08-04 07:01:30)
> On Sat, 30 Jul 2022 at 01:56, Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Because it is jumbled in some range?
> Yes.
> >
> > >
> > > I do see a way to combine the clock and the reset driver, the NPCM
> > > reset driver is serving other NPCM BMC's.
> > > Should we use regmap to handle the clock registers instead of ioremap?
> >
> > Sure? Using regmap or not looks like a parallel discussion. How does it
> > help use platform APIs?
> I mean to use regmap API instead of platform API for handing the clock
> and reset registers.
> the regmap API gives only one user access to R/W (lock).
> I will be happy to get more suggestions, on how should we solve this situation.
> 

Using platform APIs means using platform_*() functions, not of_*()
functions, which are open-firmware/DT related. Regmap can be used to
operate on registers mapped as __iomem, which is different from platform
APIs.

Is having a lock even necessary? Do the reset and clk controls live
within a shared register where we would need to prevent one driver from
accessing that register at the same time as the other?
Tomer Maimon Aug. 8, 2022, 12:37 p.m. UTC | #10
Hi Stephen,

Thanks for your reply.

On Thu, 4 Aug 2022 at 23:05, Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Tomer Maimon (2022-08-04 07:01:30)
> > On Sat, 30 Jul 2022 at 01:56, Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > Because it is jumbled in some range?
> > Yes.
> > >
> > > >
> > > > I do see a way to combine the clock and the reset driver, the NPCM
> > > > reset driver is serving other NPCM BMC's.
> > > > Should we use regmap to handle the clock registers instead of ioremap?
> > >
> > > Sure? Using regmap or not looks like a parallel discussion. How does it
> > > help use platform APIs?
> > I mean to use regmap API instead of platform API for handing the clock
> > and reset registers.
> > the regmap API gives only one user access to R/W (lock).
> > I will be happy to get more suggestions, on how should we solve this situation.
> >
>
> Using platform APIs means using platform_*() functions, not of_*()
> functions, which are open-firmware/DT related. Regmap can be used to
> operate on registers mapped as __iomem, which is different from platform
> APIs.
I will use platform_get_resource() and devm_ioremap_resource()
functions in the next version.

>
> Is having a lock even necessary? Do the reset and clk controls live
You are right,  lock use is not necessary.
> within a shared register where we would need to prevent one driver from
> accessing that register at the same time as the other?
reset and clk drivers are living fine with shared registers, we don't
need to handle the register access between the clk and the reset
drivers.

Best regards,

Tomer
Tomer Maimon Aug. 8, 2022, 1:08 p.m. UTC | #11
Hi Stephen,

Sorry, just to make it clear.

On Mon, 8 Aug 2022 at 15:37, Tomer Maimon <tmaimon77@gmail.com> wrote:
>
> Hi Stephen,
>
> Thanks for your reply.
>
> On Thu, 4 Aug 2022 at 23:05, Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Tomer Maimon (2022-08-04 07:01:30)
> > > On Sat, 30 Jul 2022 at 01:56, Stephen Boyd <sboyd@kernel.org> wrote:
> > > >
> > > > Because it is jumbled in some range?
> > > Yes.
> > > >
> > > > >
> > > > > I do see a way to combine the clock and the reset driver, the NPCM
> > > > > reset driver is serving other NPCM BMC's.
> > > > > Should we use regmap to handle the clock registers instead of ioremap?
> > > >
> > > > Sure? Using regmap or not looks like a parallel discussion. How does it
> > > > help use platform APIs?
> > > I mean to use regmap API instead of platform API for handing the clock
> > > and reset registers.
> > > the regmap API gives only one user access to R/W (lock).
> > > I will be happy to get more suggestions, on how should we solve this situation.
> > >
> >
> > Using platform APIs means using platform_*() functions, not of_*()
> > functions, which are open-firmware/DT related. Regmap can be used to
> > operate on registers mapped as __iomem, which is different from platform
> > APIs.
> I will use platform_get_resource() and devm_ioremap_resource()
> functions in the next version.
I will use platform_get_resource() and ioremap() function next
veriosn, is it fine?
>
> >
> > Is having a lock even necessary? Do the reset and clk controls live
> You are right,  lock use is not necessary.
> > within a shared register where we would need to prevent one driver from
> > accessing that register at the same time as the other?
> reset and clk drivers are living fine with shared registers, we don't
> need to handle the register access between the clk and the reset
> drivers.
>
> Best regards,
>
> Tomer

Best regards,

Tomer
Stephen Boyd Aug. 9, 2022, 6:02 p.m. UTC | #12
Quoting Tomer Maimon (2022-08-08 06:08:08)
> On Mon, 8 Aug 2022 at 15:37, Tomer Maimon <tmaimon77@gmail.com> wrote:
> > > Using platform APIs means using platform_*() functions, not of_*()
> > > functions, which are open-firmware/DT related. Regmap can be used to
> > > operate on registers mapped as __iomem, which is different from platform
> > > APIs.
> > I will use platform_get_resource() and devm_ioremap_resource()
> > functions in the next version.
> I will use platform_get_resource() and ioremap() function next
> veriosn, is it fine?

As stated earlier it will work for now but eventually you'll get patches
from janitors trying to convert to a devm based API that reserves the
register region. Can you ioremap the register once and register an
auxiliary device and driver for the reset (or clk) part so that the
driver can be moved out to the drivers/reset/ path?