[v4,2/3] PCI: dwc: Add Qualcomm PCIe Endpoint controller driver

Add driver support for Qualcomm PCIe Endpoint controller driver based on
the Designware core with added Qualcomm specific wrapper around the
core. The driver support is very basic such that it supports only
enumeration, PCIe read/write, and MSI. There is no ASPM and PM support
for now but these will be added later.

The driver is capable of using the PERST# and WAKE# side-band GPIOs for
operation and written on top of the DWC PCI framework.

Co-developed-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>

[mani: restructured the driver and fixed several bugs for upstream]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

---
 drivers/pci/controller/dwc/Kconfig        |  10 +
 drivers/pci/controller/dwc/Makefile       |   1 +
 drivers/pci/controller/dwc/pcie-qcom-ep.c | 751 ++++++++++++++++++++++
 3 files changed, 762 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-qcom-ep.c

-- 
2.25.1

(). On Thu, Jun 24, 2021 at 1:26 AM Manivannan Sadhasivam
<manivannan.sadhasivam@linaro.org> wrote:
>
> Add driver support for Qualcomm PCIe Endpoint controller driver based on
> the Designware core with added Qualcomm specific wrapper around the
> core. The driver support is very basic such that it supports only
> enumeration, PCIe read/write, and MSI. There is no ASPM and PM support
> for now but these will be added later.
>
> The driver is capable of using the PERST# and WAKE# side-band GPIOs for
> operation and written on top of the DWC PCI framework.
>
> Co-developed-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
> Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
> [mani: restructured the driver and fixed several bugs for upstream]
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
>  drivers/pci/controller/dwc/Kconfig        |  10 +
>  drivers/pci/controller/dwc/Makefile       |   1 +
>  drivers/pci/controller/dwc/pcie-qcom-ep.c | 751 ++++++++++++++++++++++
>  3 files changed, 762 insertions(+)
>  create mode 100644 drivers/pci/controller/dwc/pcie-qcom-ep.c
>
> diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
> index 423d35872ce4..eedfe57dadad 100644
> --- a/drivers/pci/controller/dwc/Kconfig
> +++ b/drivers/pci/controller/dwc/Kconfig
> @@ -180,6 +180,16 @@ config PCIE_QCOM
>           PCIe controller uses the DesignWare core plus Qualcomm-specific
>           hardware wrappers.
>
> +config PCIE_QCOM_EP
> +       tristate "Qualcomm PCIe controller - Endpoint mode"
> +       depends on OF && (ARCH_QCOM || COMPILE_TEST)
> +       depends on PCI_ENDPOINT
> +       select PCIE_DW_EP
> +       help
> +         Say Y here to enable support for the PCIe controllers on Qualcomm SoCs
> +         to work in endpoint mode. The PCIe controller uses the DesignWare core
> +         plus Qualcomm-specific hardware wrappers.
> +
>  config PCIE_ARMADA_8K
>         bool "Marvell Armada-8K PCIe controller"
>         depends on ARCH_MVEBU || COMPILE_TEST
> diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
> index eca805c1a023..abb27642d46b 100644
> --- a/drivers/pci/controller/dwc/Makefile
> +++ b/drivers/pci/controller/dwc/Makefile
> @@ -12,6 +12,7 @@ obj-$(CONFIG_PCI_KEYSTONE) += pci-keystone.o
>  obj-$(CONFIG_PCI_LAYERSCAPE) += pci-layerscape.o
>  obj-$(CONFIG_PCI_LAYERSCAPE_EP) += pci-layerscape-ep.o
>  obj-$(CONFIG_PCIE_QCOM) += pcie-qcom.o
> +obj-$(CONFIG_PCIE_QCOM_EP) += pcie-qcom-ep.o
>  obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
>  obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
>  obj-$(CONFIG_PCIE_INTEL_GW) += pcie-intel-gw.o
> diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> new file mode 100644
> index 000000000000..d824eb2e57d9
> --- /dev/null
> +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c
> @@ -0,0 +1,751 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Qualcomm PCIe Endpoint controller driver
> + *
> + * Copyright (c) 2020, The Linux Foundation. All rights reserved.
> + * Author: Siddartha Mohanadoss <smohanad@codeaurora.org
> + *
> + * Copyright (c) 2021, Linaro Ltd.
> + * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +#include <linux/regmap.h>
> +#include <linux/reset.h>
> +
> +#include "pcie-designware.h"
> +
> +/* PARF registers */
> +#define PARF_SYS_CTRL                          0x00
> +#define PARF_DB_CTRL                           0x10
> +#define PARF_PM_CTRL                           0x20
> +#define PARF_MHI_BASE_ADDR_LOWER               0x178
> +#define PARF_MHI_BASE_ADDR_UPPER               0x17c
> +#define PARF_DEBUG_INT_EN                      0x190
> +#define PARF_AXI_MSTR_RD_HALT_NO_WRITES                0x1a4
> +#define PARF_AXI_MSTR_WR_ADDR_HALT             0x1a8
> +#define PARF_Q2A_FLUSH                         0x1aC
> +#define PARF_LTSSM                             0x1b0
> +#define PARF_CFG_BITS                          0x210
> +#define PARF_INT_ALL_STATUS                    0x224
> +#define PARF_INT_ALL_CLEAR                     0x228
> +#define PARF_INT_ALL_MASK                      0x22c
> +#define PARF_SLV_ADDR_MSB_CTRL                 0x2c0
> +#define PARF_DBI_BASE_ADDR                     0x350
> +#define PARF_DBI_BASE_ADDR_HI                  0x354
> +#define PARF_SLV_ADDR_SPACE_SIZE               0x358
> +#define PARF_SLV_ADDR_SPACE_SIZE_HI            0x35c
> +#define PARF_ATU_BASE_ADDR                     0x634
> +#define PARF_ATU_BASE_ADDR_HI                  0x638
> +#define PARF_SRIS_MODE                         0x644
> +#define PARF_DEVICE_TYPE                       0x1000
> +#define PARF_BDF_TO_SID_CFG                    0x2c00

A bunch of these defines are already in pcie-qcom.c. Make a header for
the registers and common bits.

> +
> +/* ELBI registers */
> +#define ELBI_SYS_STTS                          0x08
> +
> +/* DBI registers */
> +#define DBI_CAP_ID_NXT_PTR                     0x40
> +#define DBI_CON_STATUS                         0x44
> +#define DBI_DEVICE_CAPABILITIES                        0x74
> +#define DBI_LINK_CAPABILITIES                  0x7c
> +#define DBI_LINK_CONTROL2_LINK_STATUS2         0xa0
> +#define DBI_L1SUB_CAPABILITY                   0x234

These are all standard PCIe config space registers. Use standard
defines and the offsets are discoverable.

> +#define DBI_ACK_F_ASPM_CTRL                    0x70c
> +#define DBI_GEN3_RELATED_OFF                   0x890
> +#define DBI_AUX_CLK_FREQ                       0xb40
> +
> +#define DBI_L0S_ACCPT_LATENCY_MASK             GENMASK(8, 6)
> +#define DBI_L1_ACCPT_LATENCY_MASK              GENMASK(11, 9)
> +#define DBI_L0S_EXIT_LATENCY_MASK              GENMASK(14, 12)
> +#define DBI_L1_EXIT_LATENCY_MASK               GENMASK(17, 15)
> +#define DBI_ACK_N_FTS_MASK                     GENMASK(15, 8)

Standard DWC DBI registers. Use defines in pcie-designware.h and
really any code touching these registers belongs in the common DWC
code.

> +
> +#define XMLH_LINK_UP                           0x400
> +#define CORE_RESET_TIME_US_MIN                 1000
> +#define CORE_RESET_TIME_US_MAX                 1005
> +#define WAKE_DELAY_US                          2000 /* 2 ms */
> +
> +#define to_pcie_ep(x)                          dev_get_drvdata((x)->dev)
> +
> +enum qcom_pcie_ep_link_status {
> +       QCOM_PCIE_EP_LINK_DISABLED,
> +       QCOM_PCIE_EP_LINK_ENABLED,
> +       QCOM_PCIE_EP_LINK_UP,
> +       QCOM_PCIE_EP_LINK_DOWN,
> +};
> +
> +enum qcom_pcie_ep_irq {
> +       QCOM_PCIE_EP_INT_RESERVED,
> +       QCOM_PCIE_EP_INT_LINK_DOWN,
> +       QCOM_PCIE_EP_INT_BME,
> +       QCOM_PCIE_EP_INT_PM_TURNOFF,
> +       QCOM_PCIE_EP_INT_DEBUG,
> +       QCOM_PCIE_EP_INT_LTR,
> +       QCOM_PCIE_EP_INT_MHI_Q6,
> +       QCOM_PCIE_EP_INT_MHI_A7,
> +       QCOM_PCIE_EP_INT_DSTATE_CHANGE,
> +       QCOM_PCIE_EP_INT_L1SUB_TIMEOUT,
> +       QCOM_PCIE_EP_INT_MMIO_WRITE,
> +       QCOM_PCIE_EP_INT_CFG_WRITE,
> +       QCOM_PCIE_EP_INT_BRIDGE_FLUSH_N,
> +       QCOM_PCIE_EP_INT_LINK_UP,
> +       QCOM_PCIE_EP_INT_AER_LEGACY,
> +       QCOM_PCIE_EP_INT_PLS_ERR,
> +       QCOM_PCIE_EP_INT_PME_LEGACY,
> +       QCOM_PCIE_EP_INT_PLS_PME,
> +       QCOM_PCIE_EP_INT_MAX,
> +};
> +
> +static struct clk_bulk_data qcom_pcie_ep_clks[] = {
> +       { .id = "cfg" },
> +       { .id = "aux" },
> +       { .id = "bus_master" },
> +       { .id = "bus_slave" },
> +       { .id = "ref" },
> +       { .id = "sleep" },
> +       { .id = "slave_q2a" },
> +};
> +
> +struct qcom_pcie_ep {
> +       struct dw_pcie pci;
> +
> +       void __iomem *parf;
> +       void __iomem *elbi;
> +       void __iomem *mmio;
> +       struct regmap *perst_map;
> +
> +       struct reset_control *core_reset;
> +       struct gpio_desc *reset;
> +       struct gpio_desc *wake;
> +       struct phy *phy;
> +
> +       resource_size_t dbi_phys;
> +       resource_size_t atu_phys;

These 2 are never used.

> +       resource_size_t mmio_phys;
> +       u32 mmio_size;

'mmio' is a horrible name. It's all MMIO. Is this 'addr_space' used by
other EP drivers?

Just save a pointer to the resource if you need these. Or retrieve the
resource in the one place you need it.

> +       u32 perst_en;
> +       u32 perst_sep_en;
> +
> +       enum qcom_pcie_ep_link_status link_status;
> +       int global_irq;
> +       int perst_irq;
> +};
> +
> +static void qcom_pcie_ep_enable_ltssm(struct qcom_pcie_ep *pcie_ep)
> +{
> +       u32 reg;
> +
> +       reg = readl(pcie_ep->parf + PARF_LTSSM);
> +       reg |= BIT(8);
> +       writel(reg, pcie_ep->parf + PARF_LTSSM);
> +}

Same function as qcom_pcie_2_3_2_ltssm_enable().


> +
> +static int qcom_pcie_ep_core_reset(struct qcom_pcie_ep *pcie_ep)
> +{
> +       struct dw_pcie *pci = &pcie_ep->pci;
> +       struct device *dev = pci->dev;
> +       int ret;
> +
> +       ret = reset_control_assert(pcie_ep->core_reset);
> +       if (ret) {
> +               dev_err(dev, "Cannot assert core reset\n");
> +               return ret;
> +       }
> +
> +       usleep_range(CORE_RESET_TIME_US_MIN, CORE_RESET_TIME_US_MAX);
> +
> +       ret = reset_control_deassert(pcie_ep->core_reset);
> +       if (ret) {
> +               dev_err(dev, "Cannot de-assert core reset\n");
> +               return ret;
> +       }
> +
> +       usleep_range(CORE_RESET_TIME_US_MIN, CORE_RESET_TIME_US_MAX);
> +
> +       return 0;
> +}
> +
> +/*
> + * Delatch PERST_EN and PERST_SEPARATION_ENABLE with TCSR to avoid
> + * device reset during host reboot and hibernation. The driver is
> + * expected to handle this situation.
> + */
> +static void qcom_pcie_ep_configure_tcsr(struct qcom_pcie_ep *pcie_ep)
> +{
> +       regmap_write(pcie_ep->perst_map, pcie_ep->perst_en, 0);
> +       regmap_write(pcie_ep->perst_map, pcie_ep->perst_sep_en, 0);
> +}
> +
> +static int qcom_pcie_ep_enable_resources(struct qcom_pcie_ep *pcie_ep)
> +{
> +       return clk_bulk_prepare_enable(ARRAY_SIZE(qcom_pcie_ep_clks),
> +                                      qcom_pcie_ep_clks);
> +}
> +
> +static void qcom_pcie_ep_disable_resources(struct qcom_pcie_ep *pcie_ep)
> +{
> +       clk_bulk_disable_unprepare(ARRAY_SIZE(qcom_pcie_ep_clks),
> +                                  qcom_pcie_ep_clks);
> +}
> +
> +static int qcom_pcie_ep_core_init(struct qcom_pcie_ep *pcie_ep)
> +{
> +       struct dw_pcie *pci = &pcie_ep->pci;
> +       u32 val;
> +
> +       /* Disable BDF to SID mapping */
> +       val = readl(pcie_ep->parf + PARF_BDF_TO_SID_CFG);
> +       val |= BIT(0);
> +       writel(val, pcie_ep->parf + PARF_BDF_TO_SID_CFG);
> +
> +       /* Enable debug IRQ */
> +       writel((BIT(3) | BIT(2) | BIT(1)), pcie_ep->parf + PARF_DEBUG_INT_EN);
> +
> +       /* Configure PCIe to endpoint mode */
> +       writel(0x0, pcie_ep->parf + PARF_DEVICE_TYPE);
> +
> +       /* Allow entering L1 state */
> +       val = readl(pcie_ep->parf + PARF_PM_CTRL);
> +       val &= ~BIT(5);
> +       writel(val, pcie_ep->parf + PARF_PM_CTRL);
> +
> +       /* Read halts write */
> +       writel(0x0, pcie_ep->parf + PARF_AXI_MSTR_RD_HALT_NO_WRITES);
> +       /* Write after write halt */
> +       writel(BIT(31), pcie_ep->parf + PARF_AXI_MSTR_WR_ADDR_HALT);
> +       /* Q2A flush disable */
> +       writel(0, pcie_ep->parf + PARF_Q2A_FLUSH);
> +
> +       /* Disable the DBI Wakeup */
> +       writel(BIT(11), pcie_ep->parf + PARF_SYS_CTRL);
> +       /* Disable the debouncers */
> +       writel(0x73, pcie_ep->parf + PARF_DB_CTRL);
> +       /* Disable core clock CGC */
> +       writel(BIT(6), pcie_ep->parf + PARF_SYS_CTRL);
> +       /* Set AUX power to be on */
> +       writel(BIT(4), pcie_ep->parf + PARF_SYS_CTRL);
> +       /* Request to exit from L1SS for MSI and LTR MSG */
> +       writel(BIT(1), pcie_ep->parf + PARF_CFG_BITS);
> +
> +       dw_pcie_dbi_ro_wr_en(pci);
> +
> +       /* Set the PMC Register - to support PME in D0/D3hot/D3cold */
> +       val = dw_pcie_readl_dbi(pci, DBI_CAP_ID_NXT_PTR);
> +       val |= BIT(31) | BIT(30) | BIT(27);
> +       dw_pcie_writel_dbi(pci, DBI_CAP_ID_NXT_PTR, val);
> +
> +       /* Set the Endpoint L0s Acceptable Latency to 1us (max) */
> +       val = dw_pcie_readl_dbi(pci, DBI_DEVICE_CAPABILITIES);
> +       val |= FIELD_PREP(DBI_L0S_ACCPT_LATENCY_MASK, 0x7);
> +       dw_pcie_writel_dbi(pci, DBI_DEVICE_CAPABILITIES, val);
> +
> +       /* Set the Endpoint L1 Acceptable Latency to 1us (max) */
> +       val = dw_pcie_readl_dbi(pci, DBI_DEVICE_CAPABILITIES);
> +       val |= FIELD_PREP(DBI_L1_ACCPT_LATENCY_MASK, 0x7);
> +       dw_pcie_writel_dbi(pci, DBI_DEVICE_CAPABILITIES, val);
> +
> +       /* Set the L0s Exit Latency to 2us-4us = 0x6 */
> +       val = dw_pcie_readl_dbi(pci, DBI_LINK_CAPABILITIES);
> +       val |= FIELD_PREP(DBI_L0S_EXIT_LATENCY_MASK, 0x6);
> +       dw_pcie_writel_dbi(pci, DBI_LINK_CAPABILITIES, val);
> +
> +       /* Set the L1 Exit Latency to be 32us-64 us = 0x6 */
> +       val = dw_pcie_readl_dbi(pci, DBI_LINK_CAPABILITIES);
> +       val |= FIELD_PREP(DBI_L1_EXIT_LATENCY_MASK, 0x6);
> +       dw_pcie_writel_dbi(pci, DBI_LINK_CAPABILITIES, val);
> +
> +       /* L1ss is supported */
> +       val = dw_pcie_readl_dbi(pci, DBI_L1SUB_CAPABILITY);
> +       val |= 0x1f;
> +       dw_pcie_writel_dbi(pci, DBI_L1SUB_CAPABILITY, val);
> +
> +       /* Enable Clock Power Management */
> +       val = dw_pcie_readl_dbi(pci, DBI_LINK_CAPABILITIES);
> +       val |= BIT(18);
> +       dw_pcie_writel_dbi(pci, DBI_LINK_CAPABILITIES, val);

Lots of magic values that need defines.

> +
> +       dw_pcie_dbi_ro_wr_dis(pci);
> +
> +       /* Set FTS value to match the PHY setting */
> +       val = dw_pcie_readl_dbi(pci, DBI_ACK_F_ASPM_CTRL);
> +       val |= FIELD_PREP(DBI_ACK_N_FTS_MASK, 0x80);
> +       dw_pcie_writel_dbi(pci, DBI_ACK_F_ASPM_CTRL, val);
> +
> +       writel(0, pcie_ep->parf + PARF_INT_ALL_MASK);
> +       val = BIT(QCOM_PCIE_EP_INT_LINK_DOWN) |
> +               BIT(QCOM_PCIE_EP_INT_BME) |
> +               BIT(QCOM_PCIE_EP_INT_PM_TURNOFF) |
> +               BIT(QCOM_PCIE_EP_INT_DSTATE_CHANGE) |
> +               BIT(QCOM_PCIE_EP_INT_LINK_UP);

Move BIT() into the defines.

> +       writel(val, pcie_ep->parf + PARF_INT_ALL_MASK);
> +
> +       return 0;
> +}
> +
> +static int qcom_pcie_confirm_linkup(struct dw_pcie *pci)
> +{
> +       struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
> +       u32 reg;
> +
> +       reg = readl(pcie_ep->elbi + ELBI_SYS_STTS);
> +
> +       return reg & XMLH_LINK_UP;
> +}
> +
> +static int qcom_pcie_start_link(struct dw_pcie *pci)
> +{
> +       struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
> +
> +       enable_irq(pcie_ep->perst_irq);
> +
> +       return 0;
> +}
> +
> +static void qcom_pcie_stop_link(struct dw_pcie *pci)
> +{
> +       struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
> +
> +       disable_irq(pcie_ep->perst_irq);
> +}
> +
> +static int qcom_pcie_establish_link(struct dw_pcie *pci)
> +{
> +       struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
> +       struct device *dev = pci->dev;
> +       int ret;
> +
> +       ret = qcom_pcie_ep_enable_resources(pcie_ep);
> +       if (ret)
> +               return ret;
> +
> +       ret = qcom_pcie_ep_core_reset(pcie_ep);
> +       if (ret)
> +               goto err_disable_resources;
> +
> +       ret = phy_init(pcie_ep->phy);
> +       if (ret)
> +               goto err_disable_resources;
> +
> +       ret = phy_power_on(pcie_ep->phy);
> +       if (ret)
> +               goto err_phy_exit;
> +
> +       /* Assert WAKE# to RC to indicate device is ready */
> +       gpiod_set_value_cansleep(pcie_ep->wake, 1);
> +       usleep_range(WAKE_DELAY_US, WAKE_DELAY_US + 500);
> +       gpiod_set_value_cansleep(pcie_ep->wake, 0);
> +
> +       qcom_pcie_ep_configure_tcsr(pcie_ep);
> +
> +       ret = qcom_pcie_ep_core_init(pcie_ep);
> +       if (ret) {
> +               dev_err(dev, "Failed to init controller: %d\n", ret);
> +               goto err_phy_power_off;
> +       }
> +
> +       ret = dw_pcie_ep_init_complete(&pcie_ep->pci.ep);
> +       if (ret) {
> +               dev_err(dev, "Failed to complete initialization: %d\n", ret);
> +               goto err_phy_power_off;
> +       }
> +
> +       /*
> +        * The physical address of the MMIO region which is exposed as the BAR
> +        * should be written to MHI BASE registers.
> +        */
> +       writel(pcie_ep->mmio_phys, pcie_ep->parf + PARF_MHI_BASE_ADDR_LOWER);
> +       writel(0, pcie_ep->parf + PARF_MHI_BASE_ADDR_UPPER);
> +
> +       dw_pcie_ep_init_notify(&pcie_ep->pci.ep);
> +
> +       qcom_pcie_ep_enable_ltssm(pcie_ep);
> +
> +       return 0;
> +
> +err_phy_power_off:
> +       phy_power_off(pcie_ep->phy);
> +err_phy_exit:
> +       phy_exit(pcie_ep->phy);
> +err_disable_resources:
> +       qcom_pcie_ep_disable_resources(pcie_ep);
> +
> +       return ret;
> +}
> +
> +static void qcom_pcie_disable_link(struct dw_pcie *pci)
> +{
> +       struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci);
> +       struct device *dev = pci->dev;
> +
> +       if (pcie_ep->link_status == QCOM_PCIE_EP_LINK_DISABLED) {
> +               dev_dbg(dev, "Link is already disabled\n");
> +               return;
> +       }
> +
> +       phy_power_off(pcie_ep->phy);
> +       phy_exit(pcie_ep->phy);
> +       qcom_pcie_ep_disable_resources(pcie_ep);
> +       pcie_ep->link_status = QCOM_PCIE_EP_LINK_DISABLED;
> +}
> +
> +/* Common DWC controller ops */
> +static const struct dw_pcie_ops pci_ops = {
> +       .link_up = qcom_pcie_confirm_linkup,
> +       .start_link = qcom_pcie_start_link,
> +       .stop_link = qcom_pcie_stop_link,
> +};
> +
> +static int qcom_pcie_ep_get_io_resources(struct platform_device *pdev,
> +                                        struct qcom_pcie_ep *pcie_ep)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct dw_pcie *pci = &pcie_ep->pci;
> +       struct device_node *syscon;
> +       struct resource *res;
> +       int ret;
> +
> +       pcie_ep->parf = devm_platform_ioremap_resource_byname(pdev, "parf");
> +       if (IS_ERR(pcie_ep->parf))
> +               return PTR_ERR(pcie_ep->parf);
> +
> +       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
> +       pci->dbi_base = devm_pci_remap_cfg_resource(dev, res);
> +       if (IS_ERR(pci->dbi_base))
> +               return PTR_ERR(pci->dbi_base);
> +       pci->dbi_base2 = pci->dbi_base;
> +       pcie_ep->dbi_phys = res->start;
> +
> +       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "elbi");
> +       pcie_ep->elbi = devm_pci_remap_cfg_resource(dev, res);
> +       if (IS_ERR(pcie_ep->elbi))
> +               return PTR_ERR(pcie_ep->elbi);
> +
> +       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu");
> +       pci->atu_base = devm_pci_remap_cfg_resource(dev, res);

The DWC core does this for you.

> +       if (IS_ERR(pci->atu_base))
> +               return PTR_ERR(pci->atu_base);
> +       pcie_ep->atu_phys = res->start;
> +
> +       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mmio");
> +       pcie_ep->mmio = devm_ioremap_resource(dev, res);
> +       if (IS_ERR(pcie_ep->mmio))
> +               return PTR_ERR(pcie_ep->mmio);
> +       pcie_ep->mmio_phys = res->start;
> +       pcie_ep->mmio_size = resource_size(res);
> +
> +       syscon = of_parse_phandle(dev->of_node, "qcom,perst-regs", 0);
> +       if (!syscon) {
> +               dev_err(dev, "Failed to parse qcom,perst-regs\n");
> +               return -EINVAL;
> +       }
> +
> +       pcie_ep->perst_map = syscon_node_to_regmap(syscon);
> +       of_node_put(syscon);
> +       if (IS_ERR(pcie_ep->perst_map))
> +               return PTR_ERR(pcie_ep->perst_map);
> +
> +       ret = of_property_read_u32_index(dev->of_node, "qcom,perst-regs",
> +                                        1, &pcie_ep->perst_en);
> +       if (ret < 0) {
> +               dev_err(dev, "No Perst Enable offset in syscon\n");
> +               return ret;
> +       }
> +
> +       ret = of_property_read_u32_index(dev->of_node, "qcom,perst-regs",
> +                                        2, &pcie_ep->perst_sep_en);
> +       if (ret < 0) {
> +               dev_err(dev, "No Perst Separation Enable offset in syscon\n");
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int qcom_pcie_ep_get_resources(struct platform_device *pdev,
> +                                     struct qcom_pcie_ep *pcie_ep)
> +{
> +       struct device *dev = &pdev->dev;
> +       int ret;
> +
> +       ret = qcom_pcie_ep_get_io_resources(pdev, pcie_ep);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Failed to get io resources %d\n", ret);
> +               return ret;
> +       }
> +
> +       ret = devm_clk_bulk_get(dev, ARRAY_SIZE(qcom_pcie_ep_clks),
> +                               qcom_pcie_ep_clks);
> +       if (ret)
> +               return ret;
> +
> +       pcie_ep->core_reset = devm_reset_control_get_exclusive(dev, "core");
> +       if (IS_ERR(pcie_ep->core_reset))
> +               return PTR_ERR(pcie_ep->core_reset);
> +
> +       pcie_ep->reset = devm_gpiod_get(dev, "reset", GPIOD_IN);
> +       if (IS_ERR(pcie_ep->reset))
> +               return PTR_ERR(pcie_ep->reset);
> +
> +       pcie_ep->wake = devm_gpiod_get_optional(dev, "wake", GPIOD_OUT_LOW);
> +       if (IS_ERR(pcie_ep->wake))
> +               return PTR_ERR(pcie_ep->wake);
> +
> +       pcie_ep->phy = devm_phy_optional_get(&pdev->dev, "pciephy");
> +       if (IS_ERR(pcie_ep->phy))
> +               ret = PTR_ERR(pcie_ep->phy);
> +
> +       return ret;
> +}
> +
> +/* TODO: Notify clients about PCIe state change */
> +static irqreturn_t qcom_pcie_ep_global_threaded_irq(int irq, void *data)
> +{
> +       struct qcom_pcie_ep *pcie_ep = data;
> +       struct dw_pcie *pci = &pcie_ep->pci;
> +       struct device *dev = pci->dev;
> +       unsigned long status = readl(pcie_ep->parf + PARF_INT_ALL_STATUS);
> +       u32 mask = readl(pcie_ep->parf + PARF_INT_ALL_MASK);
> +       u32 dstate, event, val;
> +
> +       writel(status, pcie_ep->parf + PARF_INT_ALL_CLEAR);
> +       status &= mask;
> +
> +       for_each_set_bit(event, &status, QCOM_PCIE_EP_INT_MAX) {
> +               switch (event) {
> +               case QCOM_PCIE_EP_INT_LINK_DOWN:
> +                       dev_dbg(dev, "Received Linkdown event\n");
> +                       pcie_ep->link_status = QCOM_PCIE_EP_LINK_DOWN;
> +                       break;
> +               case QCOM_PCIE_EP_INT_BME:
> +                       dev_dbg(dev, "Received BME event. Link is enabled!\n");
> +                       pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;
> +                       break;
> +               case QCOM_PCIE_EP_INT_PM_TURNOFF:
> +                       dev_dbg(dev, "Received PM Turn-off event! Entering L23\n");
> +                       val = readl(pcie_ep->parf + PARF_PM_CTRL);
> +                       val |= BIT(2);
> +                       writel(val, pcie_ep->parf + PARF_PM_CTRL);
> +                       break;
> +               case QCOM_PCIE_EP_INT_DSTATE_CHANGE:
> +                       dstate = dw_pcie_readl_dbi(pci, DBI_CON_STATUS) & 0x3;
> +                       dev_dbg(dev, "Received D%d state event\n", dstate);
> +                       if (dstate == 3) {
> +                               val = readl(pcie_ep->parf + PARF_PM_CTRL);
> +                               val |= BIT(1);
> +                               writel(val, pcie_ep->parf + PARF_PM_CTRL);
> +                       }
> +                       break;
> +               case QCOM_PCIE_EP_INT_LINK_UP:
> +                       dev_dbg(dev, "Received Linkup event. Enumeration complete!\n");
> +                       dw_pcie_ep_linkup(&pci->ep);
> +                       pcie_ep->link_status = QCOM_PCIE_EP_LINK_UP;
> +                       break;
> +               default:
> +                       dev_dbg(dev, "Received unknown event: %d\n", event);
> +                       break;
> +               }
> +       }
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t qcom_pcie_ep_perst_threaded_irq(int irq, void *data)
> +{
> +       struct qcom_pcie_ep *pcie_ep = data;
> +       struct dw_pcie *pci = &pcie_ep->pci;
> +       struct device *dev = pci->dev;
> +       u32 perst;
> +
> +       perst = gpiod_get_value(pcie_ep->reset);
> +
> +       if (perst) {
> +               dev_dbg(dev, "PERST de-asserted by host. Starting link training!\n");
> +               qcom_pcie_establish_link(pci);
> +       } else {
> +               dev_dbg(dev, "PERST asserted by host. Shutting down the PCIe link!\n");
> +               qcom_pcie_disable_link(pci);
> +       }
> +
> +       irq_set_irq_type(gpiod_to_irq(pcie_ep->reset),
> +                        (perst ? IRQF_TRIGGER_LOW : IRQF_TRIGGER_HIGH));
> +
> +       return IRQ_HANDLED;
> +}
> +
> +static int qcom_pcie_ep_enable_irq_resources(struct platform_device *pdev,
> +                                            struct qcom_pcie_ep *pcie_ep)
> +{
> +       int irq, ret;
> +
> +       irq = platform_get_irq_byname(pdev, "global");
> +       if (irq < 0) {
> +               dev_err(&pdev->dev, "Failed to get Global IRQ\n");
> +               return irq;
> +       }
> +
> +       ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
> +                                       qcom_pcie_ep_global_threaded_irq,
> +                                       IRQF_ONESHOT,
> +                                       "global_irq", pcie_ep);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Failed to request Global IRQ\n");
> +               return ret;
> +       }
> +
> +       pcie_ep->perst_irq = gpiod_to_irq(pcie_ep->reset);
> +       irq_set_status_flags(pcie_ep->perst_irq, IRQ_NOAUTOEN);
> +       ret = devm_request_threaded_irq(&pdev->dev, pcie_ep->perst_irq, NULL,
> +                                       qcom_pcie_ep_perst_threaded_irq,
> +                                       IRQF_TRIGGER_HIGH | IRQF_ONESHOT,

IRQ_TRIGGER_* should come from the DT.

> +                                       "perst_irq", pcie_ep);
> +       if (ret) {
> +               dev_err(&pdev->dev, "Failed to request PERST IRQ\n");
> +               disable_irq(irq);
> +               return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +static int qcom_pcie_ep_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
> +                                 enum pci_epc_irq_type type, u16 interrupt_num)
> +{
> +       struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +
> +       switch (type) {
> +       case PCI_EPC_IRQ_LEGACY:
> +               return dw_pcie_ep_raise_legacy_irq(ep, func_no);
> +       case PCI_EPC_IRQ_MSI:
> +               return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
> +       default:
> +               dev_err(pci->dev, "Unknown IRQ type\n");
> +               return -EINVAL;
> +       }
> +}
> +
> +static const struct pci_epc_features qcom_pcie_epc_features = {
> +       .linkup_notifier = true,
> +       .core_init_notifier = true,
> +       .msi_capable = true,
> +       .msix_capable = false,
> +};
> +
> +static const struct pci_epc_features *
> +qcom_pcie_epc_get_features(struct dw_pcie_ep *pci_ep)
> +{
> +       return &qcom_pcie_epc_features;
> +}
> +
> +static void qcom_pcie_ep_init(struct dw_pcie_ep *ep)
> +{
> +       struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> +       enum pci_barno bar;
> +
> +       for (bar = BAR_0; bar <= BAR_5; bar++)
> +               dw_pcie_ep_reset_bar(pci, bar);
> +}
> +
> +static struct dw_pcie_ep_ops pci_ep_ops = {
> +       .ep_init = qcom_pcie_ep_init,
> +       .raise_irq = qcom_pcie_ep_raise_irq,
> +       .get_features = qcom_pcie_epc_get_features,
> +};
> +
> +static int qcom_pcie_ep_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct qcom_pcie_ep *pcie_ep;
> +       int ret;
> +
> +       pcie_ep = devm_kzalloc(dev, sizeof(*pcie_ep), GFP_KERNEL);
> +       if (!pcie_ep)
> +               return -ENOMEM;
> +
> +       pcie_ep->pci.dev = dev;
> +       pcie_ep->pci.ops = &pci_ops;
> +       pcie_ep->pci.ep.ops = &pci_ep_ops;
> +       platform_set_drvdata(pdev, pcie_ep);
> +
> +       ret = qcom_pcie_ep_get_resources(pdev, pcie_ep);
> +       if (ret)
> +               return ret;
> +
> +       ret = qcom_pcie_ep_enable_resources(pcie_ep);
> +       if (ret)
> +               return ret;
> +
> +       ret = qcom_pcie_ep_core_reset(pcie_ep);
> +       if (ret)
> +               goto err_disable_resources;
> +
> +       ret = phy_init(pcie_ep->phy);
> +       if (ret)
> +               goto err_disable_resources;
> +
> +       /* PHY needs to be powered on for dw_pcie_ep_init() */
> +       ret = phy_power_on(pcie_ep->phy);
> +       if (ret)
> +               goto err_phy_exit;
> +
> +       ret = dw_pcie_ep_init(&pcie_ep->pci.ep);
> +       if (ret) {
> +               dev_err(dev, "Failed to initialize endpoint:%d\n", ret);
> +               goto err_phy_power_off;
> +       }
> +
> +       ret = qcom_pcie_ep_enable_irq_resources(pdev, pcie_ep);
> +       if (ret)
> +               goto err_phy_power_off;
> +
> +       return 0;
> +
> +err_phy_power_off:
> +       phy_power_off(pcie_ep->phy);
> +err_phy_exit:
> +       phy_exit(pcie_ep->phy);
> +err_disable_resources:
> +       qcom_pcie_ep_disable_resources(pcie_ep);
> +
> +       return ret;
> +}
> +
> +static int qcom_pcie_ep_remove(struct platform_device *pdev)
> +{
> +       struct qcom_pcie_ep *pcie_ep = platform_get_drvdata(pdev);
> +
> +       if (pcie_ep->link_status == QCOM_PCIE_EP_LINK_DISABLED)
> +               return 0;
> +
> +       phy_power_off(pcie_ep->phy);
> +       phy_exit(pcie_ep->phy);
> +       qcom_pcie_ep_disable_resources(pcie_ep);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id qcom_pcie_ep_match[] = {
> +       { .compatible = "qcom,sdx55-pcie-ep", },
> +       { }
> +};
> +
> +static struct platform_driver qcom_pcie_ep_driver = {
> +       .probe  = qcom_pcie_ep_probe,
> +       .remove = qcom_pcie_ep_remove,
> +       .driver = {
> +               .name = "qcom-pcie-ep",
> +               .of_match_table = qcom_pcie_ep_match,
> +       },
> +};
> +builtin_platform_driver(qcom_pcie_ep_driver);
> +
> +MODULE_AUTHOR("Siddartha Mohanadoss <smohanad@codeaurora.org>");
> +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
> +MODULE_DESCRIPTION("Qualcomm PCIe Endpoint controller driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.25.1
>

Hi Manivannan,

I love your patch! Yet something to improve:

[auto build test ERROR on pci/next]
[also build test ERROR on linus/master v5.13 next-20210628]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Manivannan-Sadhasivam/Add-Qualcomm-PCIe-Endpoint-driver-support/20210624-152757
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: powerpc-allmodconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/aa700b0071ecb52b6748f470a2b640f9f8986530
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Manivannan-Sadhasivam/Add-Qualcomm-PCIe-Endpoint-driver-support/20210624-152757
        git checkout aa700b0071ecb52b6748f470a2b640f9f8986530
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: ".dw_pcie_ep_raise_msi_irq" [drivers/pci/controller/dwc/pcie-qcom-ep.ko] undefined!

>> ERROR: modpost: ".dw_pcie_ep_raise_legacy_irq" [drivers/pci/controller/dwc/pcie-qcom-ep.ko] undefined!

>> ERROR: modpost: ".dw_pcie_ep_reset_bar" [drivers/pci/controller/dwc/pcie-qcom-ep.ko] undefined!


---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

On Thu, Jun 24, 2021 at 08:39:31AM -0600, Rob Herring wrote:
> (). On Thu, Jun 24, 2021 at 1:26 AM Manivannan Sadhasivam
> <manivannan.sadhasivam@linaro.org> wrote:
> >
> > Add driver support for Qualcomm PCIe Endpoint controller driver based on
> > the Designware core with added Qualcomm specific wrapper around the
> > core. The driver support is very basic such that it supports only
> > enumeration, PCIe read/write, and MSI. There is no ASPM and PM support
> > for now but these will be added later.
> >
> > The driver is capable of using the PERST# and WAKE# side-band GPIOs for
> > operation and written on top of the DWC PCI framework.
> >
> > Co-developed-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
> > Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>
> > [mani: restructured the driver and fixed several bugs for upstream]
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> >  drivers/pci/controller/dwc/Kconfig        |  10 +
> >  drivers/pci/controller/dwc/Makefile       |   1 +
> >  drivers/pci/controller/dwc/pcie-qcom-ep.c | 751 ++++++++++++++++++++++
> >  3 files changed, 762 insertions(+)
> >  create mode 100644 drivers/pci/controller/dwc/pcie-qcom-ep.c
> >

[...]

> A bunch of these defines are already in pcie-qcom.c. Make a header for
> the registers and common bits.
> 

The registers are shared but the offsets differ. By comparing, there are
just 3 registers that share the same offset. So I don't think it gives
any benefit in introducing a common header.

> > +
> > +/* ELBI registers */
> > +#define ELBI_SYS_STTS                          0x08
> > +
> > +/* DBI registers */
> > +#define DBI_CAP_ID_NXT_PTR                     0x40
> > +#define DBI_CON_STATUS                         0x44
> > +#define DBI_DEVICE_CAPABILITIES                        0x74
> > +#define DBI_LINK_CAPABILITIES                  0x7c
> > +#define DBI_LINK_CONTROL2_LINK_STATUS2         0xa0
> > +#define DBI_L1SUB_CAPABILITY                   0x234
> 
> These are all standard PCIe config space registers. Use standard
> defines and the offsets are discoverable.
> 

Okay.

> > +#define DBI_ACK_F_ASPM_CTRL                    0x70c
> > +#define DBI_GEN3_RELATED_OFF                   0x890
> > +#define DBI_AUX_CLK_FREQ                       0xb40
> > +
> > +#define DBI_L0S_ACCPT_LATENCY_MASK             GENMASK(8, 6)
> > +#define DBI_L1_ACCPT_LATENCY_MASK              GENMASK(11, 9)
> > +#define DBI_L0S_EXIT_LATENCY_MASK              GENMASK(14, 12)
> > +#define DBI_L1_EXIT_LATENCY_MASK               GENMASK(17, 15)
> > +#define DBI_ACK_N_FTS_MASK                     GENMASK(15, 8)
> 
> Standard DWC DBI registers. Use defines in pcie-designware.h and
> really any code touching these registers belongs in the common DWC
> code.
> 

Looked into this part and found that most of the DBI settings can be
skipped as the reset state is same.

In v5, there will be only DBI_CON_STATUS register in this driver for
reading the D-state in IRQ handler. I can't find any info about this
register in the PCI spec. And by judging from its location (between
PM capability register and MSI capability register), this seems to be
Qcom specific.

> > +
> > +#define XMLH_LINK_UP                           0x400
> > +#define CORE_RESET_TIME_US_MIN                 1000
> > +#define CORE_RESET_TIME_US_MAX                 1005
> > +#define WAKE_DELAY_US                          2000 /* 2 ms */
> > +
> > +#define to_pcie_ep(x)                          dev_get_drvdata((x)->dev)
> > +
> > +enum qcom_pcie_ep_link_status {
> > +       QCOM_PCIE_EP_LINK_DISABLED,
> > +       QCOM_PCIE_EP_LINK_ENABLED,
> > +       QCOM_PCIE_EP_LINK_UP,
> > +       QCOM_PCIE_EP_LINK_DOWN,
> > +};
> > +
> > +enum qcom_pcie_ep_irq {
> > +       QCOM_PCIE_EP_INT_RESERVED,
> > +       QCOM_PCIE_EP_INT_LINK_DOWN,
> > +       QCOM_PCIE_EP_INT_BME,
> > +       QCOM_PCIE_EP_INT_PM_TURNOFF,
> > +       QCOM_PCIE_EP_INT_DEBUG,
> > +       QCOM_PCIE_EP_INT_LTR,
> > +       QCOM_PCIE_EP_INT_MHI_Q6,
> > +       QCOM_PCIE_EP_INT_MHI_A7,
> > +       QCOM_PCIE_EP_INT_DSTATE_CHANGE,
> > +       QCOM_PCIE_EP_INT_L1SUB_TIMEOUT,
> > +       QCOM_PCIE_EP_INT_MMIO_WRITE,
> > +       QCOM_PCIE_EP_INT_CFG_WRITE,
> > +       QCOM_PCIE_EP_INT_BRIDGE_FLUSH_N,
> > +       QCOM_PCIE_EP_INT_LINK_UP,
> > +       QCOM_PCIE_EP_INT_AER_LEGACY,
> > +       QCOM_PCIE_EP_INT_PLS_ERR,
> > +       QCOM_PCIE_EP_INT_PME_LEGACY,
> > +       QCOM_PCIE_EP_INT_PLS_PME,
> > +       QCOM_PCIE_EP_INT_MAX,
> > +};
> > +
> > +static struct clk_bulk_data qcom_pcie_ep_clks[] = {
> > +       { .id = "cfg" },
> > +       { .id = "aux" },
> > +       { .id = "bus_master" },
> > +       { .id = "bus_slave" },
> > +       { .id = "ref" },
> > +       { .id = "sleep" },
> > +       { .id = "slave_q2a" },
> > +};
> > +
> > +struct qcom_pcie_ep {
> > +       struct dw_pcie pci;
> > +
> > +       void __iomem *parf;
> > +       void __iomem *elbi;
> > +       void __iomem *mmio;
> > +       struct regmap *perst_map;
> > +
> > +       struct reset_control *core_reset;
> > +       struct gpio_desc *reset;
> > +       struct gpio_desc *wake;
> > +       struct phy *phy;
> > +
> > +       resource_size_t dbi_phys;
> > +       resource_size_t atu_phys;
> 
> These 2 are never used.
> 

oh, that's a left over. will remove.

> > +       resource_size_t mmio_phys;
> > +       u32 mmio_size;
> 
> 'mmio' is a horrible name. It's all MMIO. Is this 'addr_space' used by
> other EP drivers?
> 

No, this is the BAR region used by the device. This region is called
MMIO in the hardware as it relates to the MHI bus and has the registers
for MHI. Calling this region by some other name will induce a confusion
since the MHI spec has been referencing this region as MMIO.

> Just save a pointer to the resource if you need these. Or retrieve the
> resource in the one place you need it.
> 

Okay

> > +       u32 perst_en;
> > +       u32 perst_sep_en;
> > +
> > +       enum qcom_pcie_ep_link_status link_status;
> > +       int global_irq;
> > +       int perst_irq;
> > +};
> > +
> > +static void qcom_pcie_ep_enable_ltssm(struct qcom_pcie_ep *pcie_ep)
> > +{
> > +       u32 reg;
> > +
> > +       reg = readl(pcie_ep->parf + PARF_LTSSM);
> > +       reg |= BIT(8);
> > +       writel(reg, pcie_ep->parf + PARF_LTSSM);
> > +}
> 
> Same function as qcom_pcie_2_3_2_ltssm_enable().
> 

this is the only function shared between RC and EP drivers...

> 
> > +

[...]

> > +
> > +       /* L1ss is supported */
> > +       val = dw_pcie_readl_dbi(pci, DBI_L1SUB_CAPABILITY);
> > +       val |= 0x1f;
> > +       dw_pcie_writel_dbi(pci, DBI_L1SUB_CAPABILITY, val);
> > +
> > +       /* Enable Clock Power Management */
> > +       val = dw_pcie_readl_dbi(pci, DBI_LINK_CAPABILITIES);
> > +       val |= BIT(18);
> > +       dw_pcie_writel_dbi(pci, DBI_LINK_CAPABILITIES, val);
> 
> Lots of magic values that need defines.
> 

Will add defines for all of them

> > +
> > +       dw_pcie_dbi_ro_wr_dis(pci);
> > +
> > +       /* Set FTS value to match the PHY setting */
> > +       val = dw_pcie_readl_dbi(pci, DBI_ACK_F_ASPM_CTRL);
> > +       val |= FIELD_PREP(DBI_ACK_N_FTS_MASK, 0x80);
> > +       dw_pcie_writel_dbi(pci, DBI_ACK_F_ASPM_CTRL, val);
> > +
> > +       writel(0, pcie_ep->parf + PARF_INT_ALL_MASK);
> > +       val = BIT(QCOM_PCIE_EP_INT_LINK_DOWN) |
> > +               BIT(QCOM_PCIE_EP_INT_BME) |
> > +               BIT(QCOM_PCIE_EP_INT_PM_TURNOFF) |
> > +               BIT(QCOM_PCIE_EP_INT_DSTATE_CHANGE) |
> > +               BIT(QCOM_PCIE_EP_INT_LINK_UP);
> 
> Move BIT() into the defines.
> 

This has been done because QCOM_PCIE_EP_INT_* are defined as enums and
shared with the IRQ handler. But I'll change these to defines with BIT()
macro and will use if() condition for matching the events in irq
handler.

> > +       writel(val, pcie_ep->parf + PARF_INT_ALL_MASK);
> > +
> > +       return 0;
> > +}
> > +

[...]

> > +
> > +       res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu");
> > +       pci->atu_base = devm_pci_remap_cfg_resource(dev, res);
> 
> The DWC core does this for you.
>

Oh yeah. I added this for getting the atu_phys address that needs to be
written to some PARF registers. But in v4 I removed that logic and
forgot to remove this.

> > +       if (IS_ERR(pci->atu_base))
> > +               return PTR_ERR(pci->atu_base);
> > +       pcie_ep->atu_phys = res->start;
> > +

[...]

> > +       pcie_ep->perst_irq = gpiod_to_irq(pcie_ep->reset);
> > +       irq_set_status_flags(pcie_ep->perst_irq, IRQ_NOAUTOEN);
> > +       ret = devm_request_threaded_irq(&pdev->dev, pcie_ep->perst_irq, NULL,
> > +                                       qcom_pcie_ep_perst_threaded_irq,
> > +                                       IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
> 
> IRQ_TRIGGER_* should come from the DT.
> 

How? We can specify the triggers in "interrupts*" property but here the
IRQ is obtained from the GPIO. So I'm not sure how to specify the
trigger in DT.

Thanks,
Mani