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Handle reboot for Exynos SoC via restart_handler

PATCH Superseded Pankaj Dubey 2 participants 5 messages Oct 7, 2014 – Nov 10, 2014

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v3 of 5 Superseded Latest is v5 →

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#0 lore raw

v3 cover Handle reboot for Exynos SoC via restart_handler

This patch removes restart hook from machine_desc of Exynos, and moves respective code into reboot_notifiers.
Exynos5440 handles reboot via clock register so let's register a restart_handler in Exynos5440 clock driver.
For rest Exynos SoC, reboot is handled via PMU SWRESET register so let's register a restart_handler in PMU driver for handling this.

This patch is inspired and dependent on following patch series[1] from Geunter Roeck.

Also this patch is dependent on PMU platform driver patch [2] by me, and has been prepared on top of it.

[1]: kernel: Add support for kernel restart handler call chain
https://lkml.org/lkml/2014/8/19/652

[2]: ARM: Exynos: Convert PMU implementation into a platform driver
https://lkml.org/lkml/2014/10/6/89

I have tested reboot functionality on Exynos3250 based board, on kgene/for-next as well as linux-next's next-20140925 tag.

Patch v2 and related discussion can be found here
http://www.spinics.net/lists/linux-samsung-soc/msg37457.html

Changes since v2:
- Used register_restart_handler instead of register_reboot_notifier.
- Updated notifier names and commit message accordingly.

Changes since v1:
- Addressed review comments from Tomasz Figa. Removed usage of local variables where ever unnecessary.
- Make reg_base as global in clk-exynos5440.c file, to avoid iomapping it again in reboot_notifier handler.

Pankaj Dubey (2):
clk: samsung: exynos5440: move restart code into clock driver
ARM: EXYNOS: PMU: move restart code into pmu driver

 arch/arm/mach-exynos/common.h        |    1 -
 arch/arm/mach-exynos/exynos.c        |   23 -----------------------
 arch/arm/mach-exynos/pmu.c           |   24 ++++++++++++++++++++++++
 drivers/clk/samsung/clk-exynos5440.c |   29 ++++++++++++++++++++++++++++-
 4 files changed, 52 insertions(+), 25 deletions(-)
Signature · 1 line
1.7.9.5
#1 lore raw

PATCH v3 1/2 clk: samsung: exynos5440: move restart code into clock driver

Let's register restart handler for Exynos5440 from it's clock driver for reboot functionality. So that we can cleanup restart hooks from machine specific file.

CC Sylwester Nawrocki <[email protected]>
CC Mike Turquette <[email protected]>
---
 arch/arm/mach-exynos/exynos.c        |   19 +------------------
 drivers/clk/samsung/clk-exynos5440.c |   29 ++++++++++++++++++++++++++++-
 2 files changed, 29 insertions(+), 19 deletions(-)
arch/arm/mach-exynos/exynos.c +1 -18
index 6b283eb..e9ddf69 100644
@@ -139,24 +139,7 @@ static struct map_desc exynos5_iodesc[] __initdata = {
 
 static void exynos_restart(enum reboot_mode mode, const char *cmd)
 {
-	struct device_node *np;
-	u32 val = 0x1;
-	void __iomem *addr = pmu_base_addr + EXYNOS_SWRESET;
-
-	if (of_machine_is_compatible("samsung,exynos5440")) {
-		u32 status;
-		np = of_find_compatible_node(NULL, NULL, "samsung,exynos5440-clock");
-
-		addr = of_iomap(np, 0) + 0xbc;
-		status = __raw_readl(addr);
-
-		addr = of_iomap(np, 0) + 0xcc;
-		val = __raw_readl(addr);
-
-		val = (val & 0xffff0000) | (status & 0xffff);
-	}
-
-	__raw_writel(val, addr);
+	__raw_writel(0x1, pmu_base_addr + EXYNOS_SWRESET);
 }
 
 static struct platform_device exynos_cpuidle = {
drivers/clk/samsung/clk-exynos5440.c +28 -1
index 00d1d00..f43b925 100644
@@ -15,6 +15,8 @@
 #include <linux/clk-provider.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
 
 #include "clk.h"
 #include "clk-pll.h"
@@ -23,6 +25,8 @@
 #define CPU_CLK_STATUS		0xfc
 #define MISC_DOUT1		0x558
 
+static void __iomem *reg_base;
+
 /* parent clock name list */
 PNAME(mout_armclk_p)	= { "cplla", "cpllb" };
 PNAME(mout_spi_p)	= { "div125", "div200" };
@@ -89,10 +93,30 @@ static const struct of_device_id ext_clk_match[] __initconst = {
 	{},
 };
 
+static int exynos5440_clk_restart_notify(struct notifier_block *this,
+		unsigned long code, void *unused)
+{
+	u32 val, status;
+
+	status = readl_relaxed(reg_base + 0xbc);
+	val = readl_relaxed(reg_base + 0xcc);
+	val = (val & 0xffff0000) | (status & 0xffff);
+	writel_relaxed(val, reg_base + 0xcc);
+
+	return NOTIFY_DONE;
+}
+
+/*
+ * Exynos5440 Clock reboot notifier, handles reboot functionality
+ */
+static struct notifier_block exynos5440_clk_restart_handler = {
+	.notifier_call = exynos5440_clk_restart_notify,
+	.priority = 128,
+};
+
 /* register exynos5440 clocks */
 static void __init exynos5440_clk_init(struct device_node *np)
 {
-	void __iomem *reg_base;
 	struct samsung_clk_provider *ctx;
 
 	reg_base = of_iomap(np, 0);
@@ -125,6 +149,9 @@ static void __init exynos5440_clk_init(struct device_node *np)
 
 	samsung_clk_of_add_provider(np, ctx);
 
+	if (register_restart_handler(&exynos5440_clk_restart_handler))
+		pr_err("exynos5440 clock can't register restart handler\n");
+
 	pr_info("Exynos5440: arm_clk = %ldHz\n", _get_rate("arm_clk"));
 	pr_info("exynos5440 clock initialization complete\n");
 }
Signature · 1 line
1.7.9.5
#2 lore raw

PATCH v3 2/2 ARM: EXYNOS: PMU: move restart code into pmu driver

In reply to Pankaj Dubey

Let's register restart handler from PMU driver for reboot functionality. So that we can remove restart hooks from machine specific file, and thus moving ahead when PMU moved to driver folder, this functionality can be reused for ARM64 based Exynos SoC's.

---
 arch/arm/mach-exynos/common.h |    1 -
 arch/arm/mach-exynos/exynos.c |    6 ------
 arch/arm/mach-exynos/pmu.c    |   24 ++++++++++++++++++++++++
 3 files changed, 24 insertions(+), 7 deletions(-)
arch/arm/mach-exynos/common.h +0 -1
index 9019d86..e8afbe6 100644
@@ -12,7 +12,6 @@
 #ifndef __ARCH_ARM_MACH_EXYNOS_COMMON_H
 #define __ARCH_ARM_MACH_EXYNOS_COMMON_H
 
-#include <linux/reboot.h>
 #include <linux/of.h>
 
 #define EXYNOS3250_SOC_ID	0xE3472000
arch/arm/mach-exynos/exynos.c +0 -6
index e9ddf69..0e0101b 100644
@@ -137,11 +137,6 @@ static struct map_desc exynos5_iodesc[] __initdata = {
 	},
 };
 
-static void exynos_restart(enum reboot_mode mode, const char *cmd)
-{
-	__raw_writel(0x1, pmu_base_addr + EXYNOS_SWRESET);
-}
-
 static struct platform_device exynos_cpuidle = {
 	.name              = "exynos_cpuidle",
 #ifdef CONFIG_ARM_EXYNOS_CPUIDLE
@@ -361,7 +356,6 @@ DT_MACHINE_START(EXYNOS_DT, "SAMSUNG EXYNOS (Flattened Device Tree)")
 	.init_machine	= exynos_dt_machine_init,
 	.init_late	= exynos_init_late,
 	.dt_compat	= exynos_dt_compat,
-	.restart	= exynos_restart,
 	.reserve	= exynos_reserve,
 	.dt_fixup	= exynos_dt_fixup,
 MACHINE_END
arch/arm/mach-exynos/pmu.c +24 -0
index 1993e08..0b84998 100644
@@ -11,7 +11,10 @@
 
 #include <linux/io.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
 #include <linux/platform_device.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
 
 #include "exynos-pmu.h"
 #include "regs-pmu.h"
@@ -439,6 +442,14 @@ static void exynos5250_pmu_init(void)
 	pmu_raw_writel(value, EXYNOS5_MASK_WDTRESET_REQUEST);
 }
 
+static int pmu_restart_notify(struct notifier_block *this,
+		unsigned long code, void *unused)
+{
+	pmu_raw_writel(0x1, EXYNOS_SWRESET);
+
+	return NOTIFY_DONE;
+}
+
 static const struct exynos_pmu_data exynos4210_pmu_data = {
 	.pmu_config	= exynos4210_pmu_config,
 };
@@ -478,11 +489,20 @@ static const struct of_device_id exynos_pmu_of_device_ids[] = {
 	{ /*sentinel*/ },
 };
 
+/*
+ * Exynos PMU reboot notifier, handles reboot functionality
+ */
+static struct notifier_block pmu_restart_handler = {
+	.notifier_call = pmu_restart_notify,
+	.priority = 128,
+};
+
 static int exynos_pmu_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *match;
 	struct device *dev = &pdev->dev;
 	struct resource *res;
+	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	pmu_base_addr = devm_ioremap_resource(dev, res);
@@ -507,6 +527,10 @@ static int exynos_pmu_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, pmu_context);
 
+	ret = register_restart_handler(&pmu_restart_handler);
+	if (ret)
+		dev_err(dev, "can't register restart handler err=%d\n", ret);
+
 	dev_dbg(dev, "Exynos PMU Driver probe done\n");
 	return 0;
 }
Signature · 1 line
1.7.9.5
#3 lore raw

v3 cover Handle reboot for Exynos SoC via restart_handler

In reply to Pankaj Dubey
Quoted 2 lines · Pankaj Dubey

This patch removes restart hook from machine_desc of Exynos, and moves respective code into reboot_notifiers.

Nitpick:

s/reboot_notifiers/restart_notifiers/

Guenter

Quoted 46 lines

Exynos5440 handles reboot via clock register so let's register a restart_handler in Exynos5440 clock driver.
For rest Exynos SoC, reboot is handled via PMU SWRESET register so let's register a restart_handler in PMU driver for handling this.

This patch is inspired and dependent on following patch series[1] from Geunter Roeck.

Also this patch is dependent on PMU platform driver patch [2] by me, and has been prepared on top of it.

[1]: kernel: Add support for kernel restart handler call chain
https://lkml.org/lkml/2014/8/19/652

[2]: ARM: Exynos: Convert PMU implementation into a platform driver
https://lkml.org/lkml/2014/10/6/89

I have tested reboot functionality on Exynos3250 based board, on kgene/for-next as well as linux-next's next-20140925 tag.

Patch v2 and related discussion can be found here
http://www.spinics.net/lists/linux-samsung-soc/msg37457.html

Changes since v2:
- Used register_restart_handler instead of register_reboot_notifier.
- Updated notifier names and commit message accordingly.

Changes since v1:
- Addressed review comments from Tomasz Figa. Removed usage of local variables where ever unnecessary.
- Make reg_base as global in clk-exynos5440.c file, to avoid iomapping it again in reboot_notifier handler.

Pankaj Dubey (2):
clk: samsung: exynos5440: move restart code into clock driver
ARM: EXYNOS: PMU: move restart code into pmu driver

 arch/arm/mach-exynos/common.h        |    1 -
 arch/arm/mach-exynos/exynos.c        |   23 -----------------------
 arch/arm/mach-exynos/pmu.c           |   24 ++++++++++++++++++++++++
 drivers/clk/samsung/clk-exynos5440.c |   29 ++++++++++++++++++++++++++++-
 4 files changed, 52 insertions(+), 25 deletions(-)
Signature · 1 line
1.7.9.5
#4 lore raw

v3 cover Handle reboot for Exynos SoC via restart_handler

In reply to Pankaj Dubey

Hi Kukjin,

Quoted 3 lines · Pankaj Dubey

Subject: [PATCH v3 0/2] Handle reboot for Exynos SoC via restart_handler

This patch removes restart hook from machine_desc of Exynos, and moves

respective

Quoted 2 lines

code into reboot_notifiers.
Exynos5440 handles reboot via clock register so let's register a

restart_handler in

Quoted 2 lines

Exynos5440 clock driver.
For rest Exynos SoC, reboot is handled via PMU SWRESET register so let's

register a

Quoted 3 lines

restart_handler in PMU driver for handling this.

This patch is inspired and dependent on following patch series[1] from

Geunter

Quoted 3 lines

Roeck.

Also this patch is dependent on PMU platform driver patch [2] by me, and

has been

Quoted 9 lines

prepared on top of it.

[1]: kernel: Add support for kernel restart handler call chain
https://lkml.org/lkml/2014/8/19/652

[2]: ARM: Exynos: Convert PMU implementation into a platform driver
https://lkml.org/lkml/2014/10/6/89

I have tested reboot functionality on Exynos3250 based board, on

kgene/for-next as

Quoted 19 lines

well as linux-next's next-20140925 tag.

Patch v2 and related discussion can be found here
http://www.spinics.net/lists/linux-samsung-soc/msg37457.html

Changes since v2:
- Used register_restart_handler instead of register_reboot_notifier.
- Updated notifier names and commit message accordingly.

Changes since v1:
- Addressed review comments from Tomasz Figa. Removed usage of local variables where ever unnecessary.
- Make reg_base as global in clk-exynos5440.c file, to avoid iomapping it again in reboot_notifier handler.

Pankaj Dubey (2):
clk: samsung: exynos5440: move restart code into clock driver
ARM: EXYNOS: PMU: move restart code into pmu driver

Quoted 8 lines
 arch/arm/mach-exynos/common.h        |    1 -
 arch/arm/mach-exynos/exynos.c        |   23 -----------------------
 arch/arm/mach-exynos/pmu.c           |   24
++++++++++++++++++++++++
 drivers/clk/samsung/clk-exynos5440.c |   29
++++++++++++++++++++++++++++-
 4 files changed, 52 insertions(+), 25 deletions(-)

Will you please look into this patch series?

Quoted 2 lines

--
1.7.9.5