[PATCH] drivers/watchdog: Adding PRCMU based WD for ux500 processors
mathieu.poirier at linaro.org
mathieu.poirier at linaro.org
Mon Aug 20 15:50:55 EDT 2012
From: "Mathieu J. Poirier" <mathieu.poirier at linaro.org>
This patch is a partial re-write of the driver developed by
Jonas Aaberg and brings it up to the new watchdog interface
now the standard in the mainline kernel.
Cc: Jonas Aaberg <jonas.aberg at stericsson.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
---
drivers/watchdog/Kconfig | 10 +++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/ux500_wdt.c | 168 +++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/ux500_wdt.h | 19 +++++
4 files changed, 198 insertions(+), 0 deletions(-)
create mode 100644 drivers/watchdog/ux500_wdt.c
create mode 100644 include/linux/mfd/ux500_wdt.h
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 53d7571..5e5f2e5 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -352,6 +352,16 @@ config IMX2_WDT
To compile this driver as a module, choose M here: the
module will be called imx2_wdt.
+config UX500_WATCHDOG
+ bool "ST-Ericsson Ux500 watchdog"
+ depends on UX500_SOC_DB8500
+ default y
+ help
+ Say Y here to include Watchdog timer support for the
+ watchdog existing in the prcmu of ST-Ericsson Ux500 series platforms.
+ This watchdog is used to reset the system and thus cannot be
+ compiled as a module.
+
# AVR32 Architecture
config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 572b39b..bec0ef8 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
+obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o
# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/ux500_wdt.c b/drivers/watchdog/ux500_wdt.c
new file mode 100644
index 0000000..7b8cfe27
--- /dev/null
+++ b/drivers/watchdog/ux500_wdt.c
@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2011
+ *
+ * License Terms: GNU General Public License v2
+ *
+ * Author: Mathieu Poirier <mathieu.poirier at linaro.org> for ST-Ericsson
+ * Author: Jonas Aaberg <jonas.aberg at stericsson.com> for ST-Ericsson
+ *
+ * Heavily based upon geodewdt.c
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/moduleparam.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/err.h>
+#include <linux/uaccess.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/ux500_wdt.h>
+#include <linux/mfd/db8500-prcmu.h>
+#include <mach/id.h>
+
+#define WATCHDOG_TIMEOUT 600 /* 10 minutes */
+#define WATCHDOG_MIN 0
+#define WATCHDOG_MAX 268435 /* 28 bit resolution in ms == 268435.455 s */
+
+static int timeout = WATCHDOG_TIMEOUT;
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. default="
+ __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+static bool wdt_en;
+static bool wdt_auto_off;
+
+static int ux500_wdt_start(struct watchdog_device *wdd)
+{
+ wdt_en = true;
+ return db8500_prcmu_enable_a9wdog(0);
+}
+
+static int ux500_wdt_stop(struct watchdog_device *wdd)
+{
+ return db8500_prcmu_disable_a9wdog(0);
+}
+
+static int ux500_wdt_keepalive(struct watchdog_device *wdd)
+{
+ return db8500_prcmu_kick_a9wdog(0);
+}
+
+static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ ux500_wdt_stop(wdd);
+ db8500_prcmu_load_a9wdog(0, timeout);
+ ux500_wdt_start(wdd);
+
+ return 0;
+}
+
+static const struct watchdog_info ux500_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .identity = "Ux500 WDT",
+ .firmware_version = 1,
+};
+
+static struct watchdog_ops ux500_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = ux500_wdt_start,
+ .stop = ux500_wdt_stop,
+ .ping = ux500_wdt_keepalive,
+ .set_timeout = ux500_wdt_set_timeout,
+
+};
+
+static struct watchdog_device ux500_wdt = {
+ .info = &ux500_wdt_info,
+ .ops = &ux500_wdt_ops,
+ .min_timeout = WATCHDOG_MIN,
+ .max_timeout = WATCHDOG_MAX,
+};
+
+static int __init ux500_wdt_probe(struct platform_device *pdev)
+{
+ int err;
+
+ watchdog_set_nowayout(&ux500_wdt, nowayout);
+
+ /* auto off on sleep */
+ db8500_prcmu_config_a9wdog(1, wdt_auto_off);
+
+ /* set HW initial value */
+ db8500_prcmu_load_a9wdog(0, timeout * 1000);
+
+ err = watchdog_register_device(&ux500_wdt);
+ if (err)
+ return err;
+
+ dev_info(&pdev->dev, "initialized\n");
+
+ return 0;
+}
+
+static int __exit ux500_wdt_remove(struct platform_device *dev)
+{
+ watchdog_unregister_device(&ux500_wdt);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int ux500_wdt_suspend(struct platform_device *pdev,
+ pm_message_t state)
+{
+ if (wdt_en && !wdt_auto_off) {
+ ux500_wdt_stop(&ux500_wdt);
+ db8500_prcmu_config_a9wdog(1, true);
+
+ db8500_prcmu_load_a9wdog(0, timeout * 1000);
+ ux500_wdt_start(&ux500_wdt);
+ }
+ return 0;
+}
+
+static int ux500_wdt_resume(struct platform_device *pdev)
+{
+ if (wdt_en && !wdt_auto_off) {
+ ux500_wdt_stop(&ux500_wdt);
+ db8500_prcmu_config_a9wdog(1, true);
+
+ db8500_prcmu_load_a9wdog(0, timeout * 1000);
+ ux500_wdt_start(&ux500_wdt);
+ }
+ return 0;
+}
+
+#else
+#define ux500_wdt_suspend NULL
+#define ux500_wdt_resume NULL
+#endif
+static struct platform_driver ux500_wdt_driver = {
+ .remove = __exit_p(ux500_wdt_remove),
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "ux500_wdt",
+ },
+ .suspend = ux500_wdt_suspend,
+ .resume = ux500_wdt_resume,
+};
+
+static int __init ux500_wdt_init(void)
+{
+ return platform_driver_probe(&ux500_wdt_driver, ux500_wdt_probe);
+}
+module_init(ux500_wdt_init);
+
+MODULE_AUTHOR("Jonas Aaberg <jonas.aberg at stericsson.com>");
+MODULE_DESCRIPTION("Ux500 Watchdog Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
diff --git a/include/linux/mfd/ux500_wdt.h b/include/linux/mfd/ux500_wdt.h
new file mode 100644
index 0000000..bfb91f1
--- /dev/null
+++ b/include/linux/mfd/ux500_wdt.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) ST Ericsson SA 2011
+ *
+ * License Terms: GNU General Public License v2
+ *
+ * STE Ux500 PRCMU API
+ */
+#ifndef __UX500_WDT_H
+#define __UX500_WDT_H
+
+/**
+ * struct ux500_wdt_data
+ */
+struct ux500_wdt_data {
+ int timeout;
+ int nowayout;
+};
+
+#endif /* __UX500_WDT_H */
--
1.7.5.4
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