[PATCH V7 0/6] Add X-Gene platform reboot mechanism

[PATCH V7 0/6] Add X-Gene platform reboot mechanism

[Feng Kan]

Enable reboot driver for the X-Gene platform. Add generic syscon reboot
driver.

V7 Change:
	- Seem V3 on, the patches were not making in to the mailinglist.
	- Fix build error produced by other ARCH while including this
	  driver. Set to depend on arm64 ARCH for now.

V6 Change:
	- Add documentation for scu node.

V5 Change:
	- Documentation update, endian and access size.

V4 Change:
	- Remove old X-Gene reboot driver
	- Add generic syscon reboot driver
	- Add DTS and Kconfig for X-Gene reboot using syscon method

V3 Change:
	- Remove the reboot driver's use of acpi resource patch.
	- Change the reboot driver to use syscon to parse out 
	  system clock register. Remove the old method of getting
	  register from the reboot driver directly.
	- Remove documentation since its now simple.

V2 Change:
	- Add support for using ACPI resource.

Feng Kan (5):
  power: reset: Add generic SYSCON register mapped reset
  power: reset: Remove X-Gene reboot driver
  arm64: dts: Add X-Gene reboot driver dts node
  arm64: Select reboot driver for X-Gene platform
  Documentation: power: reset: Add documentation for generic SYSCON
    reboot driver

 .../bindings/power/reset/syscon-reboot.txt         |   23 +++++
 arch/arm64/Kconfig                                 |    2 +
 arch/arm64/boot/dts/apm-storm.dtsi                 |   13 +++
 drivers/power/reset/Kconfig                        |    8 +-
 drivers/power/reset/Makefile                       |    2 +-
 drivers/power/reset/syscon-reboot.c                |  100 +++++++++++++++++++
 drivers/power/reset/xgene-reboot.c                 |  103 --------------------
 7 files changed, 143 insertions(+), 108 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
 create mode 100644 drivers/power/reset/syscon-reboot.c
 delete mode 100644 drivers/power/reset/xgene-reboot.c

-- 
1.7.6.1

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[PATCH V7 1/6] power: reset: Add generic SYSCON register mapped reset

[Feng Kan]

Add a generic SYSCON register mapped reset mechanism.

Signed-off-by: Feng Kan <fkan@apm.com>
---
 drivers/power/reset/Kconfig         |  6 +++
 drivers/power/reset/Makefile        |  1 +
 drivers/power/reset/syscon-reboot.c | 91 +++++++++++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+)
 create mode 100644 drivers/power/reset/syscon-reboot.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index bdcf517..7035236 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -80,3 +80,9 @@ config POWER_RESET_KEYSTONE
 	help
 	  Reboot support for the KEYSTONE SoCs.
 
+config POWER_RESET_SYSCON
+	bool "Generic SYSCON regmap reset driver"
+	depends on ARCH_XGENE
+	depends on POWER_RESET && MFD_SYSCON
+	help
+	  Reboot support for generic SYSCON mapped register reset.
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index dde2e8b..b1b5ab3 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o
 obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
 obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
 obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o
+obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o
diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c
new file mode 100644
index 0000000..9c15ba5
--- /dev/null
+++ b/drivers/power/reset/syscon-reboot.c
@@ -0,0 +1,91 @@
+/*
+ * Generic Syscon Reboot Driver
+ *
+ * Copyright (c) 2013, Applied Micro Circuits Corporation
+ * Author: Feng Kan <fkan@apm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/io.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/stat.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/reboot.h>
+#include <asm/system_misc.h>
+
+struct syscon_reboot_context {
+	struct regmap *map;
+	u32 offset;
+	u32 mask;
+};
+
+static struct syscon_reboot_context *syscon_reboot_ctx;
+
+static void syscon_restart(enum reboot_mode reboot_mode, const char *cmd)
+{
+	struct syscon_reboot_context *ctx = syscon_reboot_ctx;
+	unsigned long timeout;
+
+	/* Issue the reboot */
+	if (ctx->map)
+		regmap_write(ctx->map, ctx->offset, ctx->mask);
+
+	timeout = jiffies + HZ;
+	while (time_before(jiffies, timeout))
+		cpu_relax();
+
+	pr_emerg("Unable to restart system\n");
+}
+
+static int syscon_reboot_probe(struct platform_device *pdev)
+{
+	struct syscon_reboot_context *ctx;
+	struct device *dev = &pdev->dev;
+
+	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx) {
+		dev_err(&pdev->dev, "out of memory for context\n");
+		return -ENOMEM;
+	}
+
+	ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
+	if (IS_ERR(ctx->map))
+		return PTR_ERR(ctx->map);
+
+	if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset))
+		return -EINVAL;
+
+	if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
+		return -EINVAL;
+
+	arm_pm_restart = syscon_restart;
+	syscon_reboot_ctx = ctx;
+
+	return 0;
+}
+
+static struct of_device_id syscon_reboot_of_match[] = {
+	{ .compatible = "syscon-reboot" },
+	{}
+};
+
+static struct platform_driver syscon_reboot_driver = {
+	.probe = syscon_reboot_probe,
+	.driver = {
+		.name = "syscon-reboot",
+		.of_match_table = syscon_reboot_of_match,
+	},
+};
+module_platform_driver(syscon_reboot_driver);
-- 
1.9.1

[PATCH V7 2/6] Documentation: power: reset: Add documentation for generic SYSCON reboot driver

[Feng Kan]

Add documentation for generic SYSCON reboot driver.

Signed-off-by: Feng Kan <fkan@apm.com>
---
 .../bindings/power/reset/syscon-reboot.txt         | 23 ++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/reset/syscon-reboot.txt

diff --git a/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt b/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
new file mode 100644
index 0000000..1190631
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/reset/syscon-reboot.txt
@@ -0,0 +1,23 @@
+Generic SYSCON mapped register reset driver
+
+This is a generic reset driver using syscon to map the reset register.
+The reset is generally performed with a write to the reset register
+defined by the register map pointed by syscon reference plus the offset
+with the mask defined in the reboot node.
+
+Required properties:
+- compatible: should contain "syscon-reboot"
+- regmap: this is phandle to the register map node
+- offset: offset in the register map for the reboot register (in bytes)
+- mask: the reset value written to the reboot register (32 bit access)
+
+Default will be little endian mode, 32 bit access only.
+
+Examples:
+
+	reboot {
+	   compatible = "syscon-reboot";
+	   regmap = <&regmapnode>;
+	   offset = <0x0>;
+	   mask = <0x1>;
+	};
-- 
1.9.1

[PATCH V7 3/6] Documentation: arm64: add SCU dts binding documentation to linux kernel

[Feng Kan]

This add documentation for the SCU system clock unit device tree binding
to the kernel.

Signed-off-by: Feng Kan <fkan@apm.com>
---
 Documentation/devicetree/bindings/arm/apm/scu.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/apm/scu.txt

diff --git a/Documentation/devicetree/bindings/arm/apm/scu.txt b/Documentation/devicetree/bindings/arm/apm/scu.txt
new file mode 100644
index 0000000..b45be06
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/apm/scu.txt
@@ -0,0 +1,17 @@
+APM X-GENE SoC series SCU Registers
+
+This system clock unit contain various register that control block resets,
+clock enable/disables, clock divisors and other deepsleep registers.
+
+Properties:
+ - compatible : should contain two values. First value must be:
+		   - "apm,xgene-scu"
+		second value must be always "syscon".
+
+ - reg : offset and length of the register set.
+
+Example :
+	scu: system-clk-controller@17000000 {
+		compatible = "apm,xgene-scu","syscon";
+		reg = <0x0 0x17000000 0x0 0x400>;
+	};
-- 
1.9.1

[PATCH V7 4/6] arm64: dts: Add X-Gene reboot driver dts node

[Feng Kan]

Add X-Gene platform reboot driver dts node.

Signed-off-by: Feng Kan <fkan-qTEPVZfXA3Y@public.gmane.org>
---
 arch/arm64/boot/dts/apm-storm.dtsi | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/apm-storm.dtsi b/arch/arm64/boot/dts/apm-storm.dtsi
index 40aa96c..53e70f8 100644
--- a/arch/arm64/boot/dts/apm-storm.dtsi
+++ b/arch/arm64/boot/dts/apm-storm.dtsi
@@ -103,6 +103,11 @@
 		#size-cells = <2>;
 		ranges;
 
+		scu: system-clk-controller@17000000 {
+			compatible = "apm,xgene-scu","syscon";
+			reg = <0x0 0x17000000 0x0 0x400>;
+		};
+
 		clocks {
 			#address-cells = <2>;
 			#size-cells = <2>;
@@ -397,5 +402,12 @@
 			#clock-cells = <1>;
 			clocks = <&rtcclk 0>;
 		};
+
+		reboot@17000014 {
+			compatible = "syscon-reboot";
+			regmap = <&scu>;
+			offset = <0x14>;
+			mask = <0x1>;
+		};
 	};
 };
-- 
1.9.1

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[PATCH V7 5/6] arm64: Select reboot driver for X-Gene platform

[Feng Kan]

Select reboot driver for X-Gene platform.

Signed-off-by: Feng Kan <fkan-qTEPVZfXA3Y@public.gmane.org>
---
 arch/arm64/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a474de34..91a2e25 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -140,6 +140,8 @@ config ARCH_VEXPRESS
 
 config ARCH_XGENE
 	bool "AppliedMicro X-Gene SOC Family"
+	select MFD_SYSCON
+	select POWER_RESET_SYSCON
 	help
 	  This enables support for AppliedMicro X-Gene SOC Family
 
-- 
1.9.1

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[PATCH V7 6/6] power: reset: Remove X-Gene reboot driver

[Feng Kan]

Remove X-Gene reboot driver.

Signed-off-by: Feng Kan <fkan@apm.com>
---
 drivers/power/reset/Kconfig        |   7 ---
 drivers/power/reset/Makefile       |   1 -
 drivers/power/reset/xgene-reboot.c | 103 -------------------------------------
 3 files changed, 111 deletions(-)
 delete mode 100644 drivers/power/reset/xgene-reboot.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index 7035236..cfe444e 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -66,13 +66,6 @@ config POWER_RESET_VEXPRESS
 	  Power off and reset support for the ARM Ltd. Versatile
 	  Express boards.
 
-config POWER_RESET_XGENE
-	bool "APM SoC X-Gene reset driver"
-	depends on ARM64
-	depends on POWER_RESET
-	help
-	  Reboot support for the APM SoC X-Gene Eval boards.
-
 config POWER_RESET_KEYSTONE
 	bool "Keystone reset driver"
 	depends on ARCH_KEYSTONE
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index b1b5ab3..62088d8 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -6,6 +6,5 @@ obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
 obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
 obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o
 obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
-obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
 obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o
 obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o
diff --git a/drivers/power/reset/xgene-reboot.c b/drivers/power/reset/xgene-reboot.c
deleted file mode 100644
index ecd55f8..0000000
--- a/drivers/power/reset/xgene-reboot.c
+++ /dev/null
@@ -1,103 +0,0 @@
-/*
- * AppliedMicro X-Gene SoC Reboot Driver
- *
- * Copyright (c) 2013, Applied Micro Circuits Corporation
- * Author: Feng Kan <fkan@apm.com>
- * Author: Loc Ho <lho@apm.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- * MA 02111-1307 USA
- *
- * This driver provides system reboot functionality for APM X-Gene SoC.
- * For system shutdown, this is board specify. If a board designer
- * implements GPIO shutdown, use the gpio-poweroff.c driver.
- */
-#include <linux/io.h>
-#include <linux/of_device.h>
-#include <linux/of_address.h>
-#include <linux/platform_device.h>
-#include <linux/stat.h>
-#include <linux/slab.h>
-#include <asm/system_misc.h>
-
-struct xgene_reboot_context {
-	struct platform_device *pdev;
-	void *csr;
-	u32 mask;
-};
-
-static struct xgene_reboot_context *xgene_restart_ctx;
-
-static void xgene_restart(char str, const char *cmd)
-{
-	struct xgene_reboot_context *ctx = xgene_restart_ctx;
-	unsigned long timeout;
-
-	/* Issue the reboot */
-	if (ctx)
-		writel(ctx->mask, ctx->csr);
-
-	timeout = jiffies + HZ;
-	while (time_before(jiffies, timeout))
-		cpu_relax();
-
-	dev_emerg(&ctx->pdev->dev, "Unable to restart system\n");
-}
-
-static int xgene_reboot_probe(struct platform_device *pdev)
-{
-	struct xgene_reboot_context *ctx;
-
-	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
-	if (!ctx) {
-		dev_err(&pdev->dev, "out of memory for context\n");
-		return -ENODEV;
-	}
-
-	ctx->csr = of_iomap(pdev->dev.of_node, 0);
-	if (!ctx->csr) {
-		devm_kfree(&pdev->dev, ctx);
-		dev_err(&pdev->dev, "can not map resource\n");
-		return -ENODEV;
-	}
-
-	if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
-		ctx->mask = 0xFFFFFFFF;
-
-	ctx->pdev = pdev;
-	arm_pm_restart = xgene_restart;
-	xgene_restart_ctx = ctx;
-
-	return 0;
-}
-
-static struct of_device_id xgene_reboot_of_match[] = {
-	{ .compatible = "apm,xgene-reboot" },
-	{}
-};
-
-static struct platform_driver xgene_reboot_driver = {
-	.probe = xgene_reboot_probe,
-	.driver = {
-		.name = "xgene-reboot",
-		.of_match_table = xgene_reboot_of_match,
-	},
-};
-
-static int __init xgene_reboot_init(void)
-{
-	return platform_driver_register(&xgene_reboot_driver);
-}
-device_initcall(xgene_reboot_init);
-- 
1.9.1

Re: [PATCH V7 1/6] power: reset: Add generic SYSCON register mapped reset

[Chen-Yu Tsai]

On Thu, Jun 26, 2014 at 7:03 AM, Feng Kan <fkan@apm.com> wrote:
> Add a generic SYSCON register mapped reset mechanism.
>
> Signed-off-by: Feng Kan <fkan@apm.com>
> ---
>  drivers/power/reset/Kconfig         |  6 +++
>  drivers/power/reset/Makefile        |  1 +
>  drivers/power/reset/syscon-reboot.c | 91 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 98 insertions(+)
>  create mode 100644 drivers/power/reset/syscon-reboot.c
>
> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> index bdcf517..7035236 100644
> --- a/drivers/power/reset/Kconfig
> +++ b/drivers/power/reset/Kconfig
> @@ -80,3 +80,9 @@ config POWER_RESET_KEYSTONE
>         help
>           Reboot support for the KEYSTONE SoCs.
>
> +config POWER_RESET_SYSCON
> +       bool "Generic SYSCON regmap reset driver"
> +       depends on ARCH_XGENE

If this is supposed to be generic, why are you depending on
a certain platform?


ChenYu

> +       depends on POWER_RESET && MFD_SYSCON
> +       help
> +         Reboot support for generic SYSCON mapped register reset.
> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
> index dde2e8b..b1b5ab3 100644
> --- a/drivers/power/reset/Makefile
> +++ b/drivers/power/reset/Makefile
> @@ -8,3 +8,4 @@ obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o
>  obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
>  obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
>  obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o
> +obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o
> diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c
> new file mode 100644
> index 0000000..9c15ba5
> --- /dev/null
> +++ b/drivers/power/reset/syscon-reboot.c
> @@ -0,0 +1,91 @@
> +/*
> + * Generic Syscon Reboot Driver
> + *
> + * Copyright (c) 2013, Applied Micro Circuits Corporation
> + * Author: Feng Kan <fkan@apm.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +#include <linux/io.h>
> +#include <linux/of_device.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/stat.h>
> +#include <linux/slab.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +#include <linux/reboot.h>
> +#include <asm/system_misc.h>
> +
> +struct syscon_reboot_context {
> +       struct regmap *map;
> +       u32 offset;
> +       u32 mask;
> +};
> +
> +static struct syscon_reboot_context *syscon_reboot_ctx;
> +
> +static void syscon_restart(enum reboot_mode reboot_mode, const char *cmd)
> +{
> +       struct syscon_reboot_context *ctx = syscon_reboot_ctx;
> +       unsigned long timeout;
> +
> +       /* Issue the reboot */
> +       if (ctx->map)
> +               regmap_write(ctx->map, ctx->offset, ctx->mask);
> +
> +       timeout = jiffies + HZ;
> +       while (time_before(jiffies, timeout))
> +               cpu_relax();
> +
> +       pr_emerg("Unable to restart system\n");
> +}
> +
> +static int syscon_reboot_probe(struct platform_device *pdev)
> +{
> +       struct syscon_reboot_context *ctx;
> +       struct device *dev = &pdev->dev;
> +
> +       ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
> +       if (!ctx) {
> +               dev_err(&pdev->dev, "out of memory for context\n");
> +               return -ENOMEM;
> +       }
> +
> +       ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
> +       if (IS_ERR(ctx->map))
> +               return PTR_ERR(ctx->map);
> +
> +       if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset))
> +               return -EINVAL;
> +
> +       if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
> +               return -EINVAL;
> +
> +       arm_pm_restart = syscon_restart;
> +       syscon_reboot_ctx = ctx;
> +
> +       return 0;
> +}
> +
> +static struct of_device_id syscon_reboot_of_match[] = {
> +       { .compatible = "syscon-reboot" },
> +       {}
> +};
> +
> +static struct platform_driver syscon_reboot_driver = {
> +       .probe = syscon_reboot_probe,
> +       .driver = {
> +               .name = "syscon-reboot",
> +               .of_match_table = syscon_reboot_of_match,
> +       },
> +};
> +module_platform_driver(syscon_reboot_driver);
> --
> 1.9.1
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH V7 1/6] power: reset: Add generic SYSCON register mapped reset

[Feng Kan]

On Wed, Jun 25, 2014 at 6:38 PM, Chen-Yu Tsai <wens-jdAy2FN1RRM@public.gmane.org> wrote:
> On Thu, Jun 26, 2014 at 7:03 AM, Feng Kan <fkan-qTEPVZfXA3Y@public.gmane.org> wrote:
>> Add a generic SYSCON register mapped reset mechanism.
>>
>> Signed-off-by: Feng Kan <fkan-qTEPVZfXA3Y@public.gmane.org>
>> ---
>>  drivers/power/reset/Kconfig         |  6 +++
>>  drivers/power/reset/Makefile        |  1 +
>>  drivers/power/reset/syscon-reboot.c | 91 +++++++++++++++++++++++++++++++++++++
>>  3 files changed, 98 insertions(+)
>>  create mode 100644 drivers/power/reset/syscon-reboot.c
>>
>> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
>> index bdcf517..7035236 100644
>> --- a/drivers/power/reset/Kconfig
>> +++ b/drivers/power/reset/Kconfig
>> @@ -80,3 +80,9 @@ config POWER_RESET_KEYSTONE
>>         help
>>           Reboot support for the KEYSTONE SoCs.
>>
>> +config POWER_RESET_SYSCON
>> +       bool "Generic SYSCON regmap reset driver"
>> +       depends on ARCH_XGENE
>
> If this is supposed to be generic, why are you depending on
> a certain platform?

Yes, the problem was that it was breaking the x86 build.

>
>
> ChenYu
>
>> +       depends on POWER_RESET && MFD_SYSCON
>> +       help
>> +         Reboot support for generic SYSCON mapped register reset.
>> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
>> index dde2e8b..b1b5ab3 100644
>> --- a/drivers/power/reset/Makefile
>> +++ b/drivers/power/reset/Makefile
>> @@ -8,3 +8,4 @@ obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o
>>  obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
>>  obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
>>  obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o
>> +obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o
>> diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c
>> new file mode 100644
>> index 0000000..9c15ba5
>> --- /dev/null
>> +++ b/drivers/power/reset/syscon-reboot.c
>> @@ -0,0 +1,91 @@
>> +/*
>> + * Generic Syscon Reboot Driver
>> + *
>> + * Copyright (c) 2013, Applied Micro Circuits Corporation
>> + * Author: Feng Kan <fkan-qTEPVZfXA3Y@public.gmane.org>
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public License as
>> + * published by the Free Software Foundation; either version 2 of
>> + * the License, or (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +#include <linux/io.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/stat.h>
>> +#include <linux/slab.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/regmap.h>
>> +#include <linux/reboot.h>
>> +#include <asm/system_misc.h>
>> +
>> +struct syscon_reboot_context {
>> +       struct regmap *map;
>> +       u32 offset;
>> +       u32 mask;
>> +};
>> +
>> +static struct syscon_reboot_context *syscon_reboot_ctx;
>> +
>> +static void syscon_restart(enum reboot_mode reboot_mode, const char *cmd)
>> +{
>> +       struct syscon_reboot_context *ctx = syscon_reboot_ctx;
>> +       unsigned long timeout;
>> +
>> +       /* Issue the reboot */
>> +       if (ctx->map)
>> +               regmap_write(ctx->map, ctx->offset, ctx->mask);
>> +
>> +       timeout = jiffies + HZ;
>> +       while (time_before(jiffies, timeout))
>> +               cpu_relax();
>> +
>> +       pr_emerg("Unable to restart system\n");
>> +}
>> +
>> +static int syscon_reboot_probe(struct platform_device *pdev)
>> +{
>> +       struct syscon_reboot_context *ctx;
>> +       struct device *dev = &pdev->dev;
>> +
>> +       ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
>> +       if (!ctx) {
>> +               dev_err(&pdev->dev, "out of memory for context\n");
>> +               return -ENOMEM;
>> +       }
>> +
>> +       ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");
>> +       if (IS_ERR(ctx->map))
>> +               return PTR_ERR(ctx->map);
>> +
>> +       if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset))
>> +               return -EINVAL;
>> +
>> +       if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
>> +               return -EINVAL;
>> +
>> +       arm_pm_restart = syscon_restart;
>> +       syscon_reboot_ctx = ctx;
>> +
>> +       return 0;
>> +}
>> +
>> +static struct of_device_id syscon_reboot_of_match[] = {
>> +       { .compatible = "syscon-reboot" },
>> +       {}
>> +};
>> +
>> +static struct platform_driver syscon_reboot_driver = {
>> +       .probe = syscon_reboot_probe,
>> +       .driver = {
>> +               .name = "syscon-reboot",
>> +               .of_match_table = syscon_reboot_of_match,
>> +       },
>> +};
>> +module_platform_driver(syscon_reboot_driver);
>> --
>> 1.9.1
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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Re: [PATCH V7 1/6] power: reset: Add generic SYSCON register mapped reset

[Arnd Bergmann]

On Thursday 26 June 2014 09:51:14 Feng Kan wrote:
> >> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> >> index bdcf517..7035236 100644
> >> --- a/drivers/power/reset/Kconfig
> >> +++ b/drivers/power/reset/Kconfig
> >> @@ -80,3 +80,9 @@ config POWER_RESET_KEYSTONE
> >>         help
> >>           Reboot support for the KEYSTONE SoCs.
> >>
> >> +config POWER_RESET_SYSCON
> >> +       bool "Generic SYSCON regmap reset driver"
> >> +       depends on ARCH_XGENE
> >
> > If this is supposed to be generic, why are you depending on
> > a certain platform?
> 
> Yes, the problem was that it was breaking the x86 build.

You probably need to list the exact dependencies then, at least make
it depend on MFD_SYSCON and OF. We generally want all drivers to
build without warnings on all architectures. You can limit it to
(ARM || ARM64 || COMPILE_TEST) if you don't want it to show up on
x86 by default, but it should still be possible to build it when
COMPILE_TEST is set.

	Arnd
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