[PATCH 2/3] watchdog: add new driver for STMP3xxx and i.MX23/28

[Wolfram Sang <w.sang@pengutronix.de>]

Replace the existing STMP3xxx driver because it has enough drawbacks
that a rewrite is apropriate. The new driver is designed to use the
watchdog framework which makes it a lot smaller. It now uses an exported
function from the RTC driver to set up its registers (the old driver
silently reused the hopefully already remapped RTC registers). Also,
this driver is mach independent, while the old one still depends on a
removed mach.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
---
 drivers/watchdog/Kconfig            |   10 +++
 drivers/watchdog/Makefile           |    1 +
 drivers/watchdog/stmp3xxx_rtc_wdt.c |  139 +++++++++++++++++++++++++++++++++++
 3 files changed, 150 insertions(+), 0 deletions(-)
 create mode 100644 drivers/watchdog/stmp3xxx_rtc_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 79fd606..f024aa3 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -305,6 +305,16 @@ config STMP3XXX_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called stmp3xxx_wdt.
 
+config STMP3XXX_RTC_WATCHDOG
+	tristate "Freescale STMP3XXX & i.MX23/28 watchdog"
+	depends on RTC_DRV_STMP
+	select WATCHDOG_CORE
+	help
+	  Say Y here to include support for the watchdog timer inside
+	  the RTC for the STMP37XX/378X or i.MX23/28 SoC.
+	  To compile this driver as a module, choose M here: the
+	  module will be called stmp3xxx_rtc_wdt.
+
 config NUC900_WATCHDOG
 	tristate "Nuvoton NUC900 watchdog"
 	depends on ARCH_W90X900
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index fe893e9..308d248 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
 obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
 obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
 obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
+obj-$(CONFIG_STMP3XXX_RTC_WATCHDOG) += stmp3xxx_rtc_wdt.o
 obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
 obj-$(CONFIG_TS72XX_WATCHDOG) += ts72xx_wdt.o
 obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o
diff --git a/drivers/watchdog/stmp3xxx_rtc_wdt.c b/drivers/watchdog/stmp3xxx_rtc_wdt.c
new file mode 100644
index 0000000..4351055
--- /dev/null
+++ b/drivers/watchdog/stmp3xxx_rtc_wdt.c
@@ -0,0 +1,139 @@
+/*
+ * Watchdog driver for the RTC based watchdog in STMP3xxx and i.MX23/28
+ *
+ * Author: Wolfram Sang <w.sang@pengutronix.de>
+ *
+ * Copyright (C) 2011 Pengutronix e.K.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/stmp3xxx_rtc_wdt.h>
+
+#define WDOG_TICK_RATE 1000 /* 1 kHz clock */
+#define STMP3XXX_DEFAULT_TIMEOUT 60
+#define STMP3XXX_MAX_TIMEOUT (UINT_MAX / WDOG_TICK_RATE)
+
+static int timeout = STMP3XXX_DEFAULT_TIMEOUT;
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout period in seconds from 1 to "
+		 __MODULE_STRING(STMP3XXX_MAX_TIMEOUT) ", default "
+		 __MODULE_STRING(STMP3XXX_DEFAULT_TIMEOUT));
+
+static int wdt_start(struct watchdog_device *wdd)
+{
+	struct device *dev = watchdog_get_drvdata(wdd);
+	struct stmp3xxx_wdt_pdata *pdata = dev->platform_data;
+
+	pdata->wdt_set_timeout(dev->parent, wdd->timeout * WDOG_TICK_RATE);
+	return 0;
+}
+
+static int wdt_stop(struct watchdog_device *wdd)
+{
+	struct device *dev = watchdog_get_drvdata(wdd);
+	struct stmp3xxx_wdt_pdata *pdata = dev->platform_data;
+
+	pdata->wdt_set_timeout(dev->parent, 0);
+	return 0;
+}
+
+static int wdt_set_timeout(struct watchdog_device *wdd, unsigned new_timeout)
+{
+	struct device *dev = watchdog_get_drvdata(wdd);
+	struct stmp3xxx_wdt_pdata *pdata = dev->platform_data;
+
+	pdata->wdt_set_timeout(dev->parent, new_timeout * WDOG_TICK_RATE);
+	return 0;
+}
+
+static const struct watchdog_info stmp3xxx_wdt_ident = {
+	.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity = "STMP3XXX RTC Watchdog",
+};
+
+static const struct watchdog_ops stmp3xxx_wdt_ops = {
+	.owner = THIS_MODULE,
+	.start = wdt_start,
+	.stop = wdt_stop,
+	.set_timeout = wdt_set_timeout,
+};
+
+static struct watchdog_device stmp3xxx_wdd = {
+	.info = &stmp3xxx_wdt_ident,
+	.ops = &stmp3xxx_wdt_ops,
+	.min_timeout = 1,
+	.max_timeout = STMP3XXX_MAX_TIMEOUT,
+	.status = WATCHDOG_NOWAYOUT_INIT_STATUS,
+};
+
+static int __devinit stmp3xxx_wdt_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	watchdog_set_drvdata(&stmp3xxx_wdd, &pdev->dev);
+
+	stmp3xxx_wdd.timeout = clamp_t(unsigned, timeout, 1, STMP3XXX_MAX_TIMEOUT);
+
+	ret = watchdog_register_device(&stmp3xxx_wdd);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "cannot register watchdog device\n");
+		return ret;
+	}
+
+	dev_info(&pdev->dev, "initialized watchdog with timeout %ds\n", timeout);
+	return 0;
+}
+
+static int __devexit stmp3xxx_wdt_remove(struct platform_device *pdev)
+{
+	watchdog_unregister_device(&stmp3xxx_wdd);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int stmp3xxx_wdt_suspend(struct device *dev)
+{
+	if (stmp3xxx_wdd.status & WDOG_ACTIVE)
+		wdt_stop(&stmp3xxx_wdd);
+
+	return 0;
+}
+
+static int stmp3xxx_wdt_resume(struct device *dev)
+{
+	if (stmp3xxx_wdd.status & WDOG_ACTIVE)
+		wdt_start(&stmp3xxx_wdd);
+
+	return 0;
+}
+
+static const struct dev_pm_ops stmp3xxx_wdt_pm_ops = {
+	.suspend	= stmp3xxx_wdt_suspend,
+	.resume		= stmp3xxx_wdt_resume,
+};
+#endif
+
+static struct platform_driver stmp3xxx_wdt_driver = {
+	.driver = {
+		.name = "stmp3xxx_rtc_wdt",
+#ifdef CONFIG_PM
+		.pm	= &stmp3xxx_wdt_pm_ops,
+#endif
+	},
+	.probe = stmp3xxx_wdt_probe,
+	.remove = __devexit_p(stmp3xxx_wdt_remove),
+};
+module_platform_driver(stmp3xxx_wdt_driver);
+
+MODULE_DESCRIPTION("STMP3XXX RTC Watchdog Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
-- 
1.7.7.3