[PATCH V3 0/3] Enable X-Gene platform reboot driver.

[PATCH V3 0/3] Enable X-Gene platform reboot driver.

[Feng Kan]

Enable X-Gene platform driver for the X-Gene platform. Change the
driver to use syscon to access the system clock unit's system
reset register.

V2 Change:
	- Add support for using ACPI resource.

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.

Feng Kan (3):
  arm64: add reboot dts entry for X-Gene platform.
  arm64: Enable system reset via arch Kconfig for X-Gene system.
  power: reset: use syscon driver to parse reboot register from scu

 arch/arm64/Kconfig                 |    2 ++
 arch/arm64/boot/dts/apm-storm.dtsi |   10 ++++++++++
 drivers/power/reset/xgene-reboot.c |   33 +++++++++++++++++----------------
 3 files changed, 29 insertions(+), 16 deletions(-)

-- 
1.7.6.1

[PATCH V3 1/3] arm64: add reboot dts entry for X-Gene platform.

[Feng Kan]

Add missing dts entries for the X-Gene reboot driver.

Signed-off-by: Feng Kan <fkan@apm.com>
---
 arch/arm64/boot/dts/apm-storm.dtsi |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arm64/boot/dts/apm-storm.dtsi b/arch/arm64/boot/dts/apm-storm.dtsi
index d37d736..7beac9d 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>;
@@ -187,5 +192,10 @@
 			interrupt-parent = <&gic>;
 			interrupts = <0x0 0x4c 0x4>;
 		};
+
+		reboot@17000014 {
+			compatible = "apm,xgene-reboot";
+			apm,scu = <&scu>;
+		};
 	};
 };
-- 
1.7.6.1

[PATCH V3 2/3] arm64: Enable system reset via arch Kconfig for X-Gene system.

[Feng Kan]

Select X-Gene reboot driver for X-Gene platform.

Signed-off-by: Feng Kan <fkan@apm.com>
---
 arch/arm64/Kconfig |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 249acb9..bfdf029 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -122,6 +122,8 @@ config ARCH_VEXPRESS
 
 config ARCH_XGENE
 	bool "AppliedMicro X-Gene SOC Family"
+	select POWER_RESET_XGENE
+	select MFD_SYSCON
 	help
 	  This enables support for AppliedMicro X-Gene SOC Family
 
-- 
1.7.6.1

[PATCH V3 3/3] power: reset: use syscon driver to parse reboot register from scu

[Feng Kan]

Use the syscon driver to parse out the reboot register map and issue
reboot via the regmap function.

Signed-off-by: Feng Kan <fkan@apm.com>
---
 drivers/power/reset/xgene-reboot.c |   75 +++++++++---------------------------
 1 files changed, 19 insertions(+), 56 deletions(-)

diff --git a/drivers/power/reset/xgene-reboot.c b/drivers/power/reset/xgene-reboot.c
index ecd55f8..660ed8a 100644
--- a/drivers/power/reset/xgene-reboot.c
+++ b/drivers/power/reset/xgene-reboot.c
@@ -24,80 +24,43 @@
  * 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 <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/reboot.h>
 #include <asm/system_misc.h>
 
-struct xgene_reboot_context {
-	struct platform_device *pdev;
-	void *csr;
-	u32 mask;
-};
+#define SCU_SRST	0x14
 
-static struct xgene_reboot_context *xgene_restart_ctx;
-
-static void xgene_restart(char str, const char *cmd)
+static void xgene_restart(enum reboot_mode reboot_mode, const char *cmd)
 {
-	struct xgene_reboot_context *ctx = xgene_restart_ctx;
 	unsigned long timeout;
+	struct regmap *map;
+	unsigned int ret;
+	struct device_node *dn;
+
+	dn = of_find_node_by_name(NULL, "reboot");
+	map = syscon_regmap_lookup_by_phandle(dn, "apm,scu");
+	if (IS_ERR(map)) {
+		ret = PTR_ERR(map);
+		pr_err("Reboot driver failed to get scu regmap: %d\n", ret);
+		return;
+	}
 
-	/* Issue the reboot */
-	if (ctx)
-		writel(ctx->mask, ctx->csr);
+	regmap_write(map, SCU_SRST, 0x1);
 
 	timeout = jiffies + HZ;
 	while (time_before(jiffies, timeout))
 		cpu_relax();
 
-	dev_emerg(&ctx->pdev->dev, "Unable to restart system\n");
+	pr_emerg("Unable to restart system\n");
 }
 
-static int xgene_reboot_probe(struct platform_device *pdev)
+static int __init xgene_reboot_init(void)
 {
-	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);
-- 
1.7.6.1

Re: [PATCH V3 3/3] power: reset: use syscon driver to parse reboot register from scu

[Arnd Bergmann]

On Wednesday 15 January 2014, Feng Kan wrote:
> +static int __init xgene_reboot_init(void)
>  {
>         arm_pm_restart = xgene_restart;
>         return 0;
>  }
>  device_initcall(xgene_reboot_init);

This won't work on a generic kernel, since you unconditionally set the
pm_restart function to your own, which is broken for everything else.

Please keep the platform_driver to attach to the reboot device
as you had before. It might be good to turn this into a generic
"syscon-reset" driver that gets both the register number and
the contents to write from the device node.

	Arnd

Re: [PATCH V3 3/3] power: reset: use syscon driver to parse reboot register from scu

[Alexander Shiyan]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=utf-8, Size: 1002 bytes --]

Пятница, 17 января 2014, 17:52 +01:00 от Arnd Bergmann <arnd@arndb.de>:
> On Wednesday 15 January 2014, Feng Kan wrote:
> > +static int __init xgene_reboot_init(void)
> >  {
> >         arm_pm_restart = xgene_restart;
> >         return 0;
> >  }
> >  device_initcall(xgene_reboot_init);
> 
> This won't work on a generic kernel, since you unconditionally set the
> pm_restart function to your own, which is broken for everything else.
> 
> Please keep the platform_driver to attach to the reboot device
> as you had before. It might be good to turn this into a generic
> "syscon-reset" driver that gets both the register number and
> the contents to write from the device node.

I am not sure but think the new driver for SYSCON GPIOs can be
reused for such purpose:
http://www.spinics.net/lists/devicetree/msg18221.html

---
ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥