diff mbox series

[4/5] sifive: reset: add DM based reset driver for SiFive SoC's

Message ID 1592828876-7724-5-git-send-email-sagar.kadam@sifive.com
State Superseded
Headers show
Series add DM based reset driver for SiFive SoC's | expand

Commit Message

Sagar Shrikant Kadam June 22, 2020, 12:27 p.m. UTC
PRCI module within SiFive SoC's has register with which we can
reset the sub-systems within the SoC. The resets to DDR and ethernet
sub systems within FU540-C000 SoC are active low, and are hold low
by default on power-up. Currently these are directly asserted within
prci driver via register read/write.
With the DM based reset driver support here, we bind the reset
driver with clock (prci) driver and assert the reset signals of
both sub-system's appropriately.

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam at sifive.com>
Reviewed-by: Pragnesh Patel <Pragnesh.patel at sifive.com>
---
 arch/riscv/include/asm/arch-fu540/reset.h |  13 ++++
 drivers/clk/sifive/fu540-prci.c           |  73 ++++++++++++++----
 drivers/reset/reset-sifive.c              | 118 ++++++++++++++++++++++++++++++
 3 files changed, 189 insertions(+), 15 deletions(-)
 create mode 100644 arch/riscv/include/asm/arch-fu540/reset.h
 create mode 100644 drivers/reset/reset-sifive.c

Comments

Sean Anderson June 24, 2020, 5:04 a.m. UTC | #1
On 6/24/20 1:01 AM, Bin Meng wrote:
> Hi Sean,
> 
> On Wed, Jun 24, 2020 at 12:17 PM Sean Anderson <seanga2 at gmail.com> wrote:
>>
>> On 6/22/20 8:27 AM, Sagar Shrikant Kadam wrote:
>>> The resets to DDR and ethernet sub-system are connected to
>>> PRCI device reset control register, these reset signals
>>> are active low and are held low at power-up. Add these reset
>>> producer and consumer details needed by the reset driver.
>>>
>>> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam at sifive.com>
>>> Reviewed-by: Pragnesh Patel <Pragnesh.patel at sifive.com>
>>> ---
>>>  arch/riscv/dts/fu540-c000-u-boot.dtsi | 10 ++++++++++
>>>  1 file changed, 10 insertions(+)
>>>
>>> diff --git a/arch/riscv/dts/fu540-c000-u-boot.dtsi b/arch/riscv/dts/fu540-c000-u-boot.dtsi
>>> index 9bba554..b37241e 100644
>>> --- a/arch/riscv/dts/fu540-c000-u-boot.dtsi
>>> +++ b/arch/riscv/dts/fu540-c000-u-boot.dtsi
>>> @@ -59,6 +59,16 @@
>>>                       reg = <0x0 0x2000000 0x0 0xc0000>;
>>>                       u-boot,dm-spl;
>>>               };
>>> +             prci: clock-controller at 10000000 {
>>
>> Shouldn't this have a compatible property?
> 
> This is the U-Boot specific dts fragment. See fu540-c000.dtsi

I ask because this node sits in /soc, and all the other nodes in /soc
have compatible strings. Since this device is bound by the clock driver,
perhaps it should be located under /soc/prci instead.

--Sean

> 
>>
>>> +                     #reset-cells = <1>;
>>> +                     resets = <&prci PRCI_RST_DDR_CTRL_N>,
>>> +                              <&prci PRCI_RST_DDR_AXI_N>,
>>> +                              <&prci PRCI_RST_DDR_AHB_N>,
>>> +                              <&prci PRCI_RST_DDR_PHY_N>,
>>> +                              <&prci PRCI_RST_GEMGXL_N>;
>>> +                     reset-names = "ddr_ctrl", "ddr_axi", "ddr_ahb",
>>> +                                     "ddr_phy", "gemgxl_reset";
>>> +             };
>>>               dmc: dmc at 100b0000 {
>>>                       compatible = "sifive,fu540-c000-ddr";
>>>                       reg = <0x0 0x100b0000 0x0 0x0800
> 
> Regards,
> Bin
>
Bin Meng June 24, 2020, 5:15 a.m. UTC | #2
Hi Sean,

On Wed, Jun 24, 2020 at 1:04 PM Sean Anderson <seanga2 at gmail.com> wrote:
>
> On 6/24/20 1:01 AM, Bin Meng wrote:
> > Hi Sean,
> >
> > On Wed, Jun 24, 2020 at 12:17 PM Sean Anderson <seanga2 at gmail.com> wrote:
> >>
> >> On 6/22/20 8:27 AM, Sagar Shrikant Kadam wrote:
> >>> The resets to DDR and ethernet sub-system are connected to
> >>> PRCI device reset control register, these reset signals
> >>> are active low and are held low at power-up. Add these reset
> >>> producer and consumer details needed by the reset driver.
> >>>
> >>> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam at sifive.com>
> >>> Reviewed-by: Pragnesh Patel <Pragnesh.patel at sifive.com>
> >>> ---
> >>>  arch/riscv/dts/fu540-c000-u-boot.dtsi | 10 ++++++++++
> >>>  1 file changed, 10 insertions(+)
> >>>
> >>> diff --git a/arch/riscv/dts/fu540-c000-u-boot.dtsi b/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >>> index 9bba554..b37241e 100644
> >>> --- a/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >>> +++ b/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >>> @@ -59,6 +59,16 @@
> >>>                       reg = <0x0 0x2000000 0x0 0xc0000>;
> >>>                       u-boot,dm-spl;
> >>>               };
> >>> +             prci: clock-controller at 10000000 {
> >>
> >> Shouldn't this have a compatible property?
> >
> > This is the U-Boot specific dts fragment. See fu540-c000.dtsi
>
> I ask because this node sits in /soc, and all the other nodes in /soc
> have compatible strings. Since this device is bound by the clock driver,
> perhaps it should be located under /soc/prci instead.

fu540-c000.dtsi has everything you asked.

Regards,
Bin
Sean Anderson June 24, 2020, 5:18 a.m. UTC | #3
On 6/24/20 1:15 AM, Bin Meng wrote:
> Hi Sean,
> 
> On Wed, Jun 24, 2020 at 1:04 PM Sean Anderson <seanga2 at gmail.com> wrote:
>>
>> On 6/24/20 1:01 AM, Bin Meng wrote:
>>> Hi Sean,
>>>
>>> On Wed, Jun 24, 2020 at 12:17 PM Sean Anderson <seanga2 at gmail.com> wrote:
>>>>
>>>> On 6/22/20 8:27 AM, Sagar Shrikant Kadam wrote:
>>>>> The resets to DDR and ethernet sub-system are connected to
>>>>> PRCI device reset control register, these reset signals
>>>>> are active low and are held low at power-up. Add these reset
>>>>> producer and consumer details needed by the reset driver.
>>>>>
>>>>> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam at sifive.com>
>>>>> Reviewed-by: Pragnesh Patel <Pragnesh.patel at sifive.com>
>>>>> ---
>>>>>  arch/riscv/dts/fu540-c000-u-boot.dtsi | 10 ++++++++++
>>>>>  1 file changed, 10 insertions(+)
>>>>>
>>>>> diff --git a/arch/riscv/dts/fu540-c000-u-boot.dtsi b/arch/riscv/dts/fu540-c000-u-boot.dtsi
>>>>> index 9bba554..b37241e 100644
>>>>> --- a/arch/riscv/dts/fu540-c000-u-boot.dtsi
>>>>> +++ b/arch/riscv/dts/fu540-c000-u-boot.dtsi
>>>>> @@ -59,6 +59,16 @@
>>>>>                       reg = <0x0 0x2000000 0x0 0xc0000>;
>>>>>                       u-boot,dm-spl;
>>>>>               };
>>>>> +             prci: clock-controller at 10000000 {
>>>>
>>>> Shouldn't this have a compatible property?
>>>
>>> This is the U-Boot specific dts fragment. See fu540-c000.dtsi
>>
>> I ask because this node sits in /soc, and all the other nodes in /soc
>> have compatible strings. Since this device is bound by the clock driver,
>> perhaps it should be located under /soc/prci instead.
> 
> fu540-c000.dtsi has everything you asked.
> 

Ah, I didn't see that this was an extension. Looks good to me.

--Sean
Bin Meng June 24, 2020, 5:35 a.m. UTC | #4
On Mon, Jun 22, 2020 at 8:28 PM Sagar Shrikant Kadam
<sagar.kadam at sifive.com> wrote:
>
> PRCI module within SiFive SoC's has register with which we can
> reset the sub-systems within the SoC. The resets to DDR and ethernet
> sub systems within FU540-C000 SoC are active low, and are hold low
> by default on power-up. Currently these are directly asserted within
> prci driver via register read/write.
> With the DM based reset driver support here, we bind the reset
> driver with clock (prci) driver and assert the reset signals of
> both sub-system's appropriately.
>
> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam at sifive.com>
> Reviewed-by: Pragnesh Patel <Pragnesh.patel at sifive.com>
> ---
>  arch/riscv/include/asm/arch-fu540/reset.h |  13 ++++
>  drivers/clk/sifive/fu540-prci.c           |  73 ++++++++++++++----
>  drivers/reset/reset-sifive.c              | 118 ++++++++++++++++++++++++++++++
>  3 files changed, 189 insertions(+), 15 deletions(-)
>  create mode 100644 arch/riscv/include/asm/arch-fu540/reset.h
>  create mode 100644 drivers/reset/reset-sifive.c
>

Reviewed-by: Bin Meng <bin.meng at windriver.com>
Tested-by: Bin Meng <bin.meng at windriver.com>
Sagar Shrikant Kadam June 24, 2020, 6:53 a.m. UTC | #5
Hi,

> -----Original Message-----
> From: Sean Anderson <seanga2 at gmail.com>
> Sent: Wednesday, June 24, 2020 10:49 AM
> To: Bin Meng <bmeng.cn at gmail.com>
> Cc: Sagar Kadam <sagar.kadam at sifive.com>; U-Boot Mailing List <u-
> boot at lists.denx.de>; Rick Chen <rick at andestech.com>; Paul Walmsley (
> Sifive) <paul.walmsley at sifive.com>; Palmer Dabbelt
> <palmer at dabbelt.com>; Anup Patel <anup.patel at wdc.com>; Atish Patra
> <atish.patra at wdc.com>; Lukasz Majewski <lukma at denx.de>; Pragnesh
> Patel <pragnesh.patel at sifive.com>; Jagan Teki
> <jagan at amarulasolutions.com>; Simon Glass <sjg at chromium.org>;
> twoerner at gmail.com; Patrick Wildt <patrick at blueri.se>; Fabio Estevam
> <festevam at gmail.com>; Weijie Gao <weijie.gao at mediatek.com>; Eugeniy
> Paltsev <Eugeniy.Paltsev at synopsys.com>
> Subject: Re: [PATCH 4/5] sifive: reset: add DM based reset driver for SiFive
> SoC's
> 
> [External Email] Do not click links or attachments unless you recognize the
> sender and know the content is safe
> 
> On 6/24/20 1:15 AM, Bin Meng wrote:
> > Hi Sean,
> >
> > On Wed, Jun 24, 2020 at 1:04 PM Sean Anderson <seanga2 at gmail.com>
> wrote:
> >>
> >> On 6/24/20 1:01 AM, Bin Meng wrote:
> >>> Hi Sean,
> >>>
> >>> On Wed, Jun 24, 2020 at 12:17 PM Sean Anderson
> <seanga2 at gmail.com> wrote:
> >>>>
> >>>> On 6/22/20 8:27 AM, Sagar Shrikant Kadam wrote:
> >>>>> The resets to DDR and ethernet sub-system are connected to PRCI
> >>>>> device reset control register, these reset signals are active low
> >>>>> and are held low at power-up. Add these reset producer and
> >>>>> consumer details needed by the reset driver.
> >>>>>
> >>>>> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam at sifive.com>
> >>>>> Reviewed-by: Pragnesh Patel <Pragnesh.patel at sifive.com>
> >>>>> ---
> >>>>>  arch/riscv/dts/fu540-c000-u-boot.dtsi | 10 ++++++++++
> >>>>>  1 file changed, 10 insertions(+)
> >>>>>
> >>>>> diff --git a/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >>>>> b/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >>>>> index 9bba554..b37241e 100644
> >>>>> --- a/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >>>>> +++ b/arch/riscv/dts/fu540-c000-u-boot.dtsi
> >>>>> @@ -59,6 +59,16 @@
> >>>>>                       reg = <0x0 0x2000000 0x0 0xc0000>;
> >>>>>                       u-boot,dm-spl;
> >>>>>               };
> >>>>> +             prci: clock-controller at 10000000 {
> >>>>
> >>>> Shouldn't this have a compatible property?
> >>>
> >>> This is the U-Boot specific dts fragment. See fu540-c000.dtsi
> >>
> >> I ask because this node sits in /soc, and all the other nodes in /soc
> >> have compatible strings. Since this device is bound by the clock
> >> driver, perhaps it should be located under /soc/prci instead.
> >
> > fu540-c000.dtsi has everything you asked.
> >
> 
> Ah, I didn't see that this was an extension. Looks good to me.
> 
> --Sean

Thanks Bin and Sean for looking at it.

BR,
Sagar Kadam
diff mbox series

Patch

diff --git a/arch/riscv/include/asm/arch-fu540/reset.h b/arch/riscv/include/asm/arch-fu540/reset.h
new file mode 100644
index 0000000..e42797a
--- /dev/null
+++ b/arch/riscv/include/asm/arch-fu540/reset.h
@@ -0,0 +1,13 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2020 SiFive, Inc.
+ *
+ * Author: Sagar Kadam <sagar.kadam at sifive.com>
+ */
+
+#ifndef __RESET_SIFIVE_H
+#define __RESET_SIFIVE_H
+
+int sifive_reset_bind(struct udevice *dev, ulong count);
+
+#endif
diff --git a/drivers/clk/sifive/fu540-prci.c b/drivers/clk/sifive/fu540-prci.c
index 57d811e..675b508 100644
--- a/drivers/clk/sifive/fu540-prci.c
+++ b/drivers/clk/sifive/fu540-prci.c
@@ -30,11 +30,15 @@ 
 
 #include <common.h>
 #include <asm/io.h>
+#include <asm/arch/reset.h>
 #include <clk-uclass.h>
 #include <clk.h>
 #include <div64.h>
 #include <dm.h>
 #include <errno.h>
+#include <reset-uclass.h>
+#include <dm/device.h>
+#include <dm/uclass.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 
@@ -131,6 +135,7 @@ 
 
 /* DEVICESRESETREG */
 #define PRCI_DEVICESRESETREG_OFFSET	0x28
+#define PRCI_DEVICERESETCNT 5
 
 #define PRCI_DEVICESRESETREG_DDR_CTRL_RST_N_MASK \
 			(0x1 << PRCI_RST_DDR_CTRL_N)
@@ -524,6 +529,41 @@  static const struct __prci_clock_ops sifive_fu540_prci_tlclksel_clk_ops = {
 	.recalc_rate = sifive_fu540_prci_tlclksel_recalc_rate,
 };
 
+static int __prci_consumer_reset(const char *rst_name, bool trigger)
+{
+	struct udevice *dev;
+	struct reset_ctl rst_sig;
+	int ret;
+
+	ret = uclass_get_device_by_driver(UCLASS_RESET,
+					  DM_GET_DRIVER(sifive_reset),
+					  &dev);
+	if (ret) {
+		dev_err(dev, "Reset driver not found: %d\n", ret);
+		return ret;
+	}
+
+	ret = reset_get_by_name(dev, rst_name, &rst_sig);
+	if (ret) {
+		dev_err(dev, "failed to get %s reset\n", rst_name);
+		return ret;
+	}
+
+	if (reset_valid(&rst_sig)) {
+		if (trigger)
+			ret = reset_deassert(&rst_sig);
+		else
+			ret = reset_assert(&rst_sig);
+		if (ret) {
+			dev_err(dev, "failed to trigger reset id = %ld\n",
+				rst_sig.id);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
 /**
  * __prci_ddr_release_reset() - Release DDR reset
  * @pd: struct __prci_data * for the PRCI containing the DDRCLK mux reg
@@ -531,19 +571,20 @@  static const struct __prci_clock_ops sifive_fu540_prci_tlclksel_clk_ops = {
  */
 static void __prci_ddr_release_reset(struct __prci_data *pd)
 {
-	u32 v;
-
-	v = __prci_readl(pd, PRCI_DEVICESRESETREG_OFFSET);
-	v |= PRCI_DEVICESRESETREG_DDR_CTRL_RST_N_MASK;
-	__prci_writel(v, PRCI_DEVICESRESETREG_OFFSET, pd);
+	/* Release DDR ctrl reset */
+	__prci_consumer_reset("ddr_ctrl", true);
 
 	/* HACK to get the '1 full controller clock cycle'. */
 	asm volatile ("fence");
-	v = __prci_readl(pd, PRCI_DEVICESRESETREG_OFFSET);
-	v |= (PRCI_DEVICESRESETREG_DDR_AXI_RST_N_MASK |
-			PRCI_DEVICESRESETREG_DDR_AHB_RST_N_MASK |
-			PRCI_DEVICESRESETREG_DDR_PHY_RST_N_MASK);
-	__prci_writel(v, PRCI_DEVICESRESETREG_OFFSET, pd);
+
+	/* Release DDR AXI reset */
+	__prci_consumer_reset("ddr_axi", true);
+
+	/* Release DDR AHB reset */
+	__prci_consumer_reset("ddr_ahb", true);
+
+	/* Release DDR PHY reset */
+	__prci_consumer_reset("ddr_phy", true);
 
 	/* HACK to get the '1 full controller clock cycle'. */
 	asm volatile ("fence");
@@ -563,12 +604,8 @@  static void __prci_ddr_release_reset(struct __prci_data *pd)
  */
 static void __prci_ethernet_release_reset(struct __prci_data *pd)
 {
-	u32 v;
-
 	/* Release GEMGXL reset */
-	v = __prci_readl(pd, PRCI_DEVICESRESETREG_OFFSET);
-	v |= PRCI_DEVICESRESETREG_GEMGXL_RST_N_MASK;
-	__prci_writel(v, PRCI_DEVICESRESETREG_OFFSET, pd);
+	__prci_consumer_reset("gemgxl_reset", true);
 
 	/* Procmon => core clock */
 	__prci_writel(PRCI_PROCMONCFG_CORE_CLOCK_MASK, PRCI_PROCMONCFG_OFFSET,
@@ -753,6 +790,11 @@  static struct clk_ops sifive_fu540_prci_ops = {
 	.disable = sifive_fu540_prci_disable,
 };
 
+static int sifive_fu540_clk_bind(struct udevice *dev)
+{
+	return sifive_reset_bind(dev, PRCI_DEVICERESETCNT);
+}
+
 static const struct udevice_id sifive_fu540_prci_ids[] = {
 	{ .compatible = "sifive,fu540-c000-prci" },
 	{ }
@@ -765,4 +807,5 @@  U_BOOT_DRIVER(sifive_fu540_prci) = {
 	.probe = sifive_fu540_prci_probe,
 	.ops = &sifive_fu540_prci_ops,
 	.priv_auto_alloc_size = sizeof(struct __prci_data),
+	.bind = sifive_fu540_clk_bind,
 };
diff --git a/drivers/reset/reset-sifive.c b/drivers/reset/reset-sifive.c
new file mode 100644
index 0000000..527757f
--- /dev/null
+++ b/drivers/reset/reset-sifive.c
@@ -0,0 +1,118 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Sifive, Inc.
+ * Author: Sagar Kadam <sagar.kadam at sifive.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <reset-uclass.h>
+#include <asm/io.h>
+#include <dm/device_compat.h>
+#include <dm/lists.h>
+#include <linux/bitops.h>
+
+#define PRCI_RESETREG_OFFSET 0x28
+
+struct sifive_reset_priv {
+	void *base;
+	/* number of reset signals */
+	int nr_reset;
+};
+
+static int sifive_rst_trigger(struct reset_ctl *rst, bool level)
+{
+	struct sifive_reset_priv *priv = dev_get_priv(rst->dev);
+	int id = rst->id;
+	int regval = readl(priv->base + PRCI_RESETREG_OFFSET);
+
+	/* Derive bitposition from rst id */
+	if (level)
+		/* Reset deassert */
+		regval |= BIT(id);
+	else
+		/* Reset assert */
+		regval &= ~BIT(id);
+
+	writel(regval, priv->base + PRCI_RESETREG_OFFSET);
+
+	return 0;
+}
+
+static int sifive_reset_assert(struct reset_ctl *rst)
+{
+	return sifive_rst_trigger(rst, false);
+}
+
+static int sifive_reset_deassert(struct reset_ctl *rst)
+{
+	return sifive_rst_trigger(rst, true);
+}
+
+static int sifive_reset_request(struct reset_ctl *rst)
+{
+	struct sifive_reset_priv *priv = dev_get_priv(rst->dev);
+
+	debug("%s(rst=%p) (dev=%p, id=%lu) (nr_reset=%d)\n", __func__,
+	      rst, rst->dev, rst->id, priv->nr_reset);
+
+	if (rst->id > priv->nr_reset)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int sifive_reset_free(struct reset_ctl *rst)
+{
+	struct sifive_reset_priv *priv = dev_get_priv(rst->dev);
+
+	debug("%s(rst=%p) (dev=%p, id=%lu) (nr_reset=%d)\n", __func__,
+	      rst, rst->dev, rst->id, priv->nr_reset);
+
+	return 0;
+}
+
+static int sifive_reset_probe(struct udevice *dev)
+{
+	struct sifive_reset_priv *priv = dev_get_priv(dev);
+
+	priv->base = dev_remap_addr(dev);
+	if (!priv->base)
+		return -ENOMEM;
+
+	return 0;
+}
+
+int sifive_reset_bind(struct udevice *dev, ulong count)
+{
+	struct udevice *rst_dev;
+	struct sifive_reset_priv *priv;
+	int ret;
+
+	ret = device_bind_driver_to_node(dev, "sifive-reset", "reset",
+					 dev_ofnode(dev), &rst_dev);
+	if (ret) {
+		dev_err(dev, "failed to bind sifive_reset driver (ret=%d)\n", ret);
+		return ret;
+	}
+	priv = malloc(sizeof(struct sifive_reset_priv));
+	priv->nr_reset = count;
+	rst_dev->priv = priv;
+
+	return 0;
+}
+
+const struct reset_ops sifive_reset_ops = {
+	.request = sifive_reset_request,
+	.rfree = sifive_reset_free,
+	.rst_assert = sifive_reset_assert,
+	.rst_deassert = sifive_reset_deassert,
+};
+
+U_BOOT_DRIVER(sifive_reset) = {
+	.name		= "sifive-reset",
+	.id		= UCLASS_RESET,
+	.ops		= &sifive_reset_ops,
+	.probe		= sifive_reset_probe,
+	.priv_auto_alloc_size = sizeof(struct sifive_reset_priv),
+};