[PATCH v2] watchdog: sirf: add watchdog driver of CSR SiRFprimaII and SiRFatlasVI

Barry Song 21cnbao at gmail.com
Wed Sep 11 22:43:48 EDT 2013


From: Xianglong Du <Xianglong.Du at csr.com>

On CSR SiRFprimaII and SiRFatlasVI, the 6th timer can act as a watchdog
timer when the Watchdog mode is enabled.

watchdog occur when TIMER watchdog counter matches the value software
pre-set, when this event occurs, the effect is the same as the system
software reset.

Signed-off-by: Xianglong Du <Xianglong.Du at csr.com>
Signed-off-by: Barry Song <Baohua.Song at csr.com>
---
 -v2: select WATCHDOG_CORE;
 module parameter name is timeout;
 fix coding style;
 define a local variable first that get's the value of watchdog_get_drvdata(wdd);
 drop redundant watchdog_timeout_invalid check;
 MODULE_ALIAS_MISCDEV is removed as we have the platform alias.

 arch/arm/boot/dts/atlas6.dtsi     |   2 +-
 arch/arm/boot/dts/prima2.dtsi     |   2 +-
 arch/arm/configs/prima2_defconfig |   6 +-
 drivers/watchdog/Kconfig          |   9 ++
 drivers/watchdog/Makefile         |   1 +
 drivers/watchdog/sirfsoc_wdt.c    | 251 ++++++++++++++++++++++++++++++++++++++
 6 files changed, 266 insertions(+), 5 deletions(-)
 create mode 100644 drivers/watchdog/sirfsoc_wdt.c

diff --git a/arch/arm/boot/dts/atlas6.dtsi b/arch/arm/boot/dts/atlas6.dtsi
index 8678e0c..afee4a1 100644
--- a/arch/arm/boot/dts/atlas6.dtsi
+++ b/arch/arm/boot/dts/atlas6.dtsi
@@ -155,7 +155,7 @@
 			       <0x56000000 0x56000000 0x1b00000>;
 
 			timer at b0020000 {
-				compatible = "sirf,prima2-tick";
+				compatible = "sirf,prima2-tick", "sirf,prima2-wdt";
 				reg = <0xb0020000 0x1000>;
 				interrupts = <0>;
 			};
diff --git a/arch/arm/boot/dts/prima2.dtsi b/arch/arm/boot/dts/prima2.dtsi
index bbeb623..d41ab98e 100644
--- a/arch/arm/boot/dts/prima2.dtsi
+++ b/arch/arm/boot/dts/prima2.dtsi
@@ -174,7 +174,7 @@
 			ranges = <0xb0000000 0xb0000000 0x180000>;
 
 			timer at b0020000 {
-				compatible = "sirf,prima2-tick";
+				compatible = "sirf,prima2-tick", "sirf,prima2-wdt";
 				reg = <0xb0020000 0x1000>;
 				interrupts = <0>;
 			};
diff --git a/arch/arm/configs/prima2_defconfig b/arch/arm/configs/prima2_defconfig
index 002a1ce..eec56e8 100644
--- a/arch/arm/configs/prima2_defconfig
+++ b/arch/arm/configs/prima2_defconfig
@@ -1,4 +1,3 @@
-CONFIG_EXPERIMENTAL=y
 CONFIG_NO_HZ=y
 CONFIG_HIGH_RES_TIMERS=y
 CONFIG_RELAY=y
@@ -39,6 +38,7 @@ CONFIG_SPI=y
 CONFIG_SPI_SIRF=y
 CONFIG_SPI_SPIDEV=y
 # CONFIG_HWMON is not set
+CONFIG_WATCHDOG=y
 CONFIG_USB_GADGET=y
 CONFIG_USB_MASS_STORAGE=m
 CONFIG_MMC=y
@@ -59,12 +59,12 @@ CONFIG_ROMFS_FS=y
 CONFIG_NLS_CODEPAGE_437=y
 CONFIG_NLS_ASCII=y
 CONFIG_NLS_ISO8859_1=y
-CONFIG_MAGIC_SYSRQ=y
+CONFIG_DEBUG_INFO=y
 CONFIG_DEBUG_SECTION_MISMATCH=y
+CONFIG_MAGIC_SYSRQ=y
 CONFIG_DEBUG_KERNEL=y
 # CONFIG_DEBUG_PREEMPT is not set
 CONFIG_DEBUG_RT_MUTEXES=y
 CONFIG_DEBUG_SPINLOCK=y
 CONFIG_DEBUG_MUTEXES=y
-CONFIG_DEBUG_INFO=y
 CONFIG_CRC_CCITT=y
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 362085d..c76cb61 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -382,6 +382,15 @@ config RETU_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called retu_wdt.
 
+config SIRFSOC_WATCHDOG
+	tristate "SiRFSOC watchdog"
+	depends on ARCH_SIRF
+	select WATCHDOG_CORE
+	default y
+	help
+	  Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When
+	  the watchdog triggers the system will be reset.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 2f26a0b..b917ae6 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -54,6 +54,7 @@ obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
 obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
 obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o
 obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o
+obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/sirfsoc_wdt.c b/drivers/watchdog/sirfsoc_wdt.c
new file mode 100644
index 0000000..0542a4d
--- /dev/null
+++ b/drivers/watchdog/sirfsoc_wdt.c
@@ -0,0 +1,251 @@
+/*
+ * Watchdog driver for CSR SiRFprimaII and SiRFatlasVI
+ *
+ * Copyright (c) 2013 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/moduleparam.h>
+#include <linux/of.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+#define SIRFSOC_TIMER_COUNTER_LO	0x0000
+#define SIRFSOC_TIMER_MATCH_0		0x0008
+#define SIRFSOC_TIMER_INT_EN		0x0024
+#define SIRFSOC_TIMER_WATCHDOG_EN	0x0028
+#define SIRFSOC_TIMER_LATCH		0x0030
+#define SIRFSOC_TIMER_LATCHED_LO	0x0034
+
+#define SIRFSOC_TIMER_WDT_INDEX		5
+
+#define SIRFSOC_WDT_MIN_TIMEOUT		30		/* 30 secs */
+#define SIRFSOC_WDT_MAX_TIMEOUT		(10 * 60)	/* 10 mins */
+#define SIRFSOC_WDT_DEFAULT_TIMEOUT	30		/* 30 secs */
+
+
+static unsigned int timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT;
+static bool nowayout = WATCHDOG_NOWAYOUT;
+
+module_param(timeout, uint, 0);
+module_param(nowayout, bool, 0);
+
+MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+			__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+static unsigned int sirfsoc_wdt_gettimeleft(struct watchdog_device *wdd)
+{
+	u32 counter, match;
+	void __iomem *wdt_base;
+	int time_left;
+
+	wdt_base = watchdog_get_drvdata(wdd);
+	counter = readl(wdt_base + SIRFSOC_TIMER_COUNTER_LO);
+	match = readl(wdt_base +
+		SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2));
+
+	if (match >= counter)
+		time_left = match-counter;
+	else
+		/* rollover */
+		time_left = (0xffffffffUL - counter) + match;
+
+	return time_left / CLOCK_TICK_RATE;
+}
+
+static int sirfsoc_wdt_updatetimeout(struct watchdog_device *wdd)
+{
+	u32 counter, timeout_ticks;
+	void __iomem *wdt_base;
+
+	timeout_ticks = wdd->timeout * CLOCK_TICK_RATE;
+	wdt_base = watchdog_get_drvdata(wdd);
+
+	/* Enable the latch before reading the LATCH_LO register */
+	writel(1, wdt_base + SIRFSOC_TIMER_LATCH);
+
+	/* Set the TO value */
+	counter = readl(wdt_base + SIRFSOC_TIMER_LATCHED_LO);
+
+	if ((0xffffffffUL - counter) >= timeout_ticks)
+		counter += timeout_ticks;
+	else
+		/* Rollover */
+		counter = timeout_ticks - (0xffffffffUL - counter);
+
+	writel(counter, wdt_base +
+		SIRFSOC_TIMER_MATCH_0 + (SIRFSOC_TIMER_WDT_INDEX << 2));
+
+	return 0;
+}
+
+static int sirfsoc_wdt_enable(struct watchdog_device *wdd)
+{
+	void __iomem *wdt_base = watchdog_get_drvdata(wdd);
+	sirfsoc_wdt_updatetimeout(wdd);
+
+	/*
+	 * NOTE: If interrupt is not enabled
+	 * then WD-Reset doesn't get generated at all.
+	 */
+	writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN)
+		| (1 << SIRFSOC_TIMER_WDT_INDEX),
+		wdt_base + SIRFSOC_TIMER_INT_EN);
+	writel(1, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN);
+
+	return 0;
+}
+
+static int sirfsoc_wdt_disable(struct watchdog_device *wdd)
+{
+	void __iomem *wdt_base = watchdog_get_drvdata(wdd);
+
+	writel(0, wdt_base + SIRFSOC_TIMER_WATCHDOG_EN);
+	writel(readl(wdt_base + SIRFSOC_TIMER_INT_EN)
+		& (~(1 << SIRFSOC_TIMER_WDT_INDEX)),
+		wdt_base + SIRFSOC_TIMER_INT_EN);
+
+	return 0;
+}
+
+static int sirfsoc_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
+{
+	wdd->timeout = to;
+	sirfsoc_wdt_updatetimeout(wdd);
+
+	return 0;
+}
+
+#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
+
+static const struct watchdog_info sirfsoc_wdt_ident = {
+	.options          =     OPTIONS,
+	.firmware_version =	0,
+	.identity         =	"SiRFSOC Watchdog",
+};
+
+static struct watchdog_ops sirfsoc_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = sirfsoc_wdt_enable,
+	.stop = sirfsoc_wdt_disable,
+	.get_timeleft = sirfsoc_wdt_gettimeleft,
+	.ping = sirfsoc_wdt_updatetimeout,
+	.set_timeout = sirfsoc_wdt_settimeout,
+};
+
+static struct watchdog_device sirfsoc_wdd = {
+	.info = &sirfsoc_wdt_ident,
+	.ops = &sirfsoc_wdt_ops,
+	.timeout = SIRFSOC_WDT_DEFAULT_TIMEOUT,
+	.min_timeout = SIRFSOC_WDT_MIN_TIMEOUT,
+	.max_timeout = SIRFSOC_WDT_MAX_TIMEOUT,
+};
+
+static int sirfsoc_wdt_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	int ret;
+	void __iomem *base;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (!base) {
+		dev_err(&pdev->dev, "sirfsoc wdt: could not remap the mem\n");
+		ret = -EADDRNOTAVAIL;
+		goto out;
+	}
+	watchdog_set_drvdata(&sirfsoc_wdd, base);
+
+	watchdog_init_timeout(&sirfsoc_wdd, timeout, &pdev->dev);
+	watchdog_set_nowayout(&sirfsoc_wdd, nowayout);
+
+	ret = watchdog_register_device(&sirfsoc_wdd);
+	if (!!ret)
+		goto out;
+
+	platform_set_drvdata(pdev, &sirfsoc_wdd);
+
+	return 0;
+
+out:
+	return ret;
+}
+
+static int sirfsoc_wdt_remove(struct platform_device *pdev)
+{
+	struct watchdog_device *wdd = platform_get_drvdata(pdev);
+
+	sirfsoc_wdt_disable(wdd);
+
+	return 0;
+}
+
+static void sirfsoc_wdt_shutdown(struct platform_device *pdev)
+{
+	struct watchdog_device *wdd = platform_get_drvdata(pdev);
+
+	sirfsoc_wdt_disable(wdd);
+}
+
+#ifdef	CONFIG_PM
+
+static int sirfsoc_wdt_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int sirfsoc_wdt_resume(struct device *dev)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	/*
+	 * NOTE: Since timer controller registers settings are saved
+	 * and restored back by the timer-prima2.c, so we need not
+	 * update WD settings except refreshing timeout.
+	 */
+	sirfsoc_wdt_updatetimeout(wdd);
+
+	return 0;
+}
+
+#else
+#define	sirfsoc_wdt_suspend		NULL
+#define	sirfsoc_wdt_resume		NULL
+#endif
+
+static const struct dev_pm_ops sirfsoc_wdt_pm_ops = {
+	.suspend = sirfsoc_wdt_suspend,
+	.resume = sirfsoc_wdt_resume,
+};
+
+static const struct of_device_id sirfsoc_wdt_of_match[] = {
+	{ .compatible = "sirf,prima2-wdt"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, sirfsoc_wdt_of_match);
+
+static struct platform_driver sirfsoc_wdt_driver = {
+	.driver = {
+		.name = "sirfsoc-wdt",
+		.owner = THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm = &sirfsoc_wdt_pm_ops,
+#endif
+		.of_match_table	= of_match_ptr(sirfsoc_wdt_of_match),
+	},
+	.probe = sirfsoc_wdt_probe,
+	.remove = sirfsoc_wdt_remove,
+	.shutdown = sirfsoc_wdt_shutdown,
+};
+module_platform_driver(sirfsoc_wdt_driver);
+
+MODULE_DESCRIPTION("SiRF SoC watchdog driver");
+MODULE_AUTHOR("Xianglong Du <Xianglong.Du at csr.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:sirfsoc-wdt");
-- 
1.8.2.3




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