[PATCHv3] Add a simple watchdog 'framework' to Barebox

[PATCHv3] Add a simple watchdog 'framework' to Barebox

[Juergen Beisert]

This patch series add a very simple watchdog command and also a user of it
for the i.MX28 SoC. The watchdog driver might also work on i.MX23, but this
is not tested yet.

This version again adds some error check and reporting, if the watchdog does
not work as expected.

The following changes since commit 075ea63a322b70d9a7a27fe0bad5f36e8e3c8bdc:

  Merge branch 'for-next/resource-size' into next (2012-06-25 14:39:10 +0200)

are available in the git repository at:

  git://git.pengutronix.de/git/jbe/barebox.git next_add_watchdog_frameworkV3

for you to fetch changes up to 4710576c2851d53529b02ac9342134672698837d:

  ARM/MXS: add a watchdog driver for i.MX28 (2012-06-26 10:37:35 +0200)

----------------------------------------------------------------
Juergen Beisert (2):
      Add a simple watchdog framework
      ARM/MXS: add a watchdog driver for i.MX28

 drivers/Kconfig            |    1 +
 drivers/Makefile           |    1 +
 drivers/watchdog/Kconfig   |   17 +++++++
 drivers/watchdog/Makefile  |    2 +
 drivers/watchdog/im28wd.c  |  121 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/watchdog/wd_core.c |   67 ++++++++++++++++++++++++
 include/watchdog.h         |   18 +++++++
 7 files changed, 227 insertions(+)
 create mode 100644 drivers/watchdog/Kconfig
 create mode 100644 drivers/watchdog/Makefile
 create mode 100644 drivers/watchdog/im28wd.c
 create mode 100644 drivers/watchdog/wd_core.c
 create mode 100644 include/watchdog.h

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[PATCH 1/2] Add a simple watchdog framework

[Juergen Beisert]

This patch adds a simple wd command which can setup, trigger and stop a watchdog
on the platform.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
---
 drivers/Kconfig            |    1 +
 drivers/Makefile           |    1 +
 drivers/watchdog/Kconfig   |   10 +++++++
 drivers/watchdog/Makefile  |    1 +
 drivers/watchdog/wd_core.c |   67 ++++++++++++++++++++++++++++++++++++++++++++
 include/watchdog.h         |   18 ++++++++++++
 6 files changed, 98 insertions(+)
 create mode 100644 drivers/watchdog/Kconfig
 create mode 100644 drivers/watchdog/Makefile
 create mode 100644 drivers/watchdog/wd_core.c
 create mode 100644 include/watchdog.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 037b0d4..e193063 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -18,5 +18,6 @@ source "drivers/input/Kconfig"
 
 source "drivers/pwm/Kconfig"
 source "drivers/dma/Kconfig"
+source "drivers/watchdog/Kconfig"
 
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index f40b321..52a44c9 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -16,3 +16,4 @@ obj-y	+= eeprom/
 obj-$(CONFIG_PWM) += pwm/
 obj-y	+= input/
 obj-y	+= dma/
+obj-y	+= watchdog/
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
new file mode 100644
index 0000000..b5970c9
--- /dev/null
+++ b/drivers/watchdog/Kconfig
@@ -0,0 +1,10 @@
+menuconfig WATCHDOG
+	bool "Watchdog support              "
+	help
+
+if WATCHDOG
+
+config WATCHDOG_CORE
+	bool
+
+endif
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
new file mode 100644
index 0000000..7a446d7
--- /dev/null
+++ b/drivers/watchdog/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_WATCHDOG_CORE) += wd_core.o
diff --git a/drivers/watchdog/wd_core.c b/drivers/watchdog/wd_core.c
new file mode 100644
index 0000000..7672529
--- /dev/null
+++ b/drivers/watchdog/wd_core.c
@@ -0,0 +1,67 @@
+/*
+ * (c) 2012 Juergen Beisert <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <common.h>
+#include <command.h>
+#include <errno.h>
+#include <linux/ctype.h>
+#include <watchdog.h>
+
+static unsigned timeout = 20; /* default timeout in [sec] */
+
+static int do_wd(int argc, char *argv[])
+{
+	int rc;
+
+	if (argc > 1) {
+		if (isdigit(*argv[1])) {
+			timeout = simple_strtoul(argv[1], NULL, 0);
+		} else {
+			printf("numerical parameter expected\n");
+			return 1;
+		}
+	}
+
+	rc = watchdog_set_timeout(timeout);
+	if (rc < 0) {
+		switch (rc) {
+		case -EINVAL:
+			printf("Timeout value out of range\n");
+			break;
+		case -ENOSYS:
+			printf("Watchdog cannot be disabled\n");
+			break;
+		default:
+			printf("Watchdog fails: '%s'\n", strerror(-rc));
+			break;
+		}
+
+		return 1;
+	}
+
+	return 0;
+}
+
+BAREBOX_CMD_HELP_START(wd)
+BAREBOX_CMD_HELP_USAGE("wd [<seconds>]\n")
+BAREBOX_CMD_HELP_SHORT("enable the watchdog to bark in <seconds> seconds. "
+		"When <seconds> is 0, the watchdog gets disabled,\n"
+		"without a parameter the watchdog will be re-triggered\n")
+BAREBOX_CMD_HELP_END
+
+BAREBOX_CMD_START(wd)
+	.cmd = do_wd,
+	.usage = "enable/disable/trigger the watchdog",
+	BAREBOX_CMD_HELP(cmd_wd_help)
+BAREBOX_CMD_END
diff --git a/include/watchdog.h b/include/watchdog.h
new file mode 100644
index 0000000..721f806
--- /dev/null
+++ b/include/watchdog.h
@@ -0,0 +1,18 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef INCLUDE_WATCHDOG_H
+# define INCLUDE_WATCHDOG_H
+
+int watchdog_set_timeout(unsigned);
+
+#endif /* INCLUDE_WATCHDOG_H */
-- 
1.7.10


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[PATCH 2/2] ARM/MXS: add a watchdog driver for i.MX28

[Juergen Beisert]

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
---
 drivers/watchdog/Kconfig  |    7 +++
 drivers/watchdog/Makefile |    1 +
 drivers/watchdog/im28wd.c |  121 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 129 insertions(+)
 create mode 100644 drivers/watchdog/im28wd.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index b5970c9..b1a73c0 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -7,4 +7,11 @@ if WATCHDOG
 config WATCHDOG_CORE
 	bool
 
+config WATCHDOG_MXS28
+	bool "i.MX28"
+	depends on ARCH_IMX28
+	select WATCHDOG_CORE
+	help
+	  Add support for watchdog management for the i.MX28 SoC.
+
 endif
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 7a446d7..b0d4d2a 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_WATCHDOG_CORE) += wd_core.o
+obj-$(CONFIG_WATCHDOG_MXS28) += im28wd.o
diff --git a/drivers/watchdog/im28wd.c b/drivers/watchdog/im28wd.c
new file mode 100644
index 0000000..b1c4809
--- /dev/null
+++ b/drivers/watchdog/im28wd.c
@@ -0,0 +1,121 @@
+/*
+ * (c) 2012 Juergen Beisert <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Note: this driver works for the i.MX28 SoC. It might work for the
+ * i.MX23 Soc as well, but is not tested yet.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <io.h>
+#include <errno.h>
+#include <malloc.h>
+
+#define MXS_RTC_CTRL 0x0
+#define MXS_RTC_SET_ADDR 0x4
+#define MXS_RTC_CLR_ADDR 0x8
+# define MXS_RTC_CTRL_WATCHDOGEN (1 << 4)
+
+#define MXS_RTC_STAT 0x10
+# define MXS_RTC_STAT_WD_PRESENT (1 << 29)
+
+#define MXS_RTC_WATCHDOG 0x50
+
+#define MXS_RTC_PERSISTENT0 0x60
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT0_EXT_RST (1 << 21)
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT0_THM_RST (1 << 20)
+
+#define MXS_RTC_PERSISTENT1 0x70
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT1_FORCE_UPDATER (1 << 31)
+
+#define MXS_RTC_DEBUG 0xc0
+
+#define WDOG_TICK_RATE 1000 /* the watchdog uses a 1 kHz clock rate */
+
+struct imx28_wd {
+	void __iomem *regs;
+	u32 timeout;
+};
+
+static struct imx28_wd *wd;
+
+/* note: 'timeout' in clock ticks */
+static void imx28_wd_set_timeout(const struct imx28_wd *p, unsigned timeout)
+{
+	void __iomem *base;
+
+	if (timeout) {
+		writel(timeout, p->regs + MXS_RTC_WATCHDOG);
+		base = p->regs + MXS_RTC_SET_ADDR;
+	} else {
+		base = p->regs + MXS_RTC_CLR_ADDR;
+	}
+	writel(MXS_RTC_CTRL_WATCHDOGEN, base + MXS_RTC_CTRL);
+	writel(MXS_RTC_PERSISTENT1_FORCE_UPDATER, base + MXS_RTC_PERSISTENT1);
+}
+
+/* note: 'timeout' in [seconds] */
+int watchdog_set_timeout(unsigned timeout)
+{
+	if (timeout > (ULONG_MAX / WDOG_TICK_RATE))
+		return -EINVAL;
+
+	imx28_wd_set_timeout(wd, timeout * WDOG_TICK_RATE);
+	return 0;
+}
+EXPORT_SYMBOL(watchdog_set_timeout);
+
+static int imx28_wd_probe(struct device_d *dev)
+{
+	struct imx28_wd *priv;
+
+	priv = xzalloc(sizeof(struct imx28_wd));
+	priv->regs = dev_request_mem_region(dev, 0);
+	priv->timeout = 20;
+	dev->priv = priv;
+	wd = priv;
+
+	if (!(readl(priv->regs + MXS_RTC_STAT) & MXS_RTC_STAT_WD_PRESENT)) {
+		free(priv);
+		return -ENODEV;
+	}
+
+	/* disable the debug feature to ensure a working WD */
+	writel(0x00000000, priv->regs + MXS_RTC_DEBUG);
+
+	return 0;
+}
+
+static void imx28_wd_remove(struct device_d *dev)
+{
+	struct imx28_wd *priv= dev->priv;
+	wd = NULL;
+	free(priv);
+}
+
+static struct driver_d imx28_wd_driver = {
+	.name   = "im28wd",
+	.probe  = imx28_wd_probe,
+	.remove = imx28_wd_remove,
+};
+
+static int imx28_wd_init(void)
+{
+	register_driver(&imx28_wd_driver);
+	return 0;
+}
+
+device_initcall(imx28_wd_init);
-- 
1.7.10


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[PATCH 2/2] ARM/MXS: add a watchdog driver for i.MX28

[Juergen Beisert]

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
---
 drivers/watchdog/Kconfig  |    6 +++
 drivers/watchdog/Makefile |    1 +
 drivers/watchdog/im28wd.c |  124 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 131 insertions(+)
 create mode 100644 drivers/watchdog/im28wd.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c734dfe..8fdc7a5 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -6,4 +6,10 @@ menuconfig WATCHDOG
 
 if WATCHDOG
 
+config WATCHDOG_MXS28
+	bool "i.MX28"
+	depends on ARCH_IMX28
+	help
+	  Add support for watchdog management for the i.MX28 SoC.
+
 endif
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 630f1b6..b29103b 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_WATCHDOG) += wd_core.o
+obj-$(CONFIG_WATCHDOG_MXS28) += im28wd.o
diff --git a/drivers/watchdog/im28wd.c b/drivers/watchdog/im28wd.c
new file mode 100644
index 0000000..b016910
--- /dev/null
+++ b/drivers/watchdog/im28wd.c
@@ -0,0 +1,124 @@
+/*
+ * (c) 2012 Juergen Beisert <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Note: this driver works for the i.MX28 SoC. It might work for the
+ * i.MX23 Soc as well, but is not tested yet.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <io.h>
+#include <errno.h>
+#include <malloc.h>
+#include <watchdog.h>
+
+#define MXS_RTC_CTRL 0x0
+#define MXS_RTC_SET_ADDR 0x4
+#define MXS_RTC_CLR_ADDR 0x8
+# define MXS_RTC_CTRL_WATCHDOGEN (1 << 4)
+
+#define MXS_RTC_STAT 0x10
+# define MXS_RTC_STAT_WD_PRESENT (1 << 29)
+
+#define MXS_RTC_WATCHDOG 0x50
+
+#define MXS_RTC_PERSISTENT0 0x60
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT0_EXT_RST (1 << 21)
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT0_THM_RST (1 << 20)
+
+#define MXS_RTC_PERSISTENT1 0x70
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT1_FORCE_UPDATER (1 << 31)
+
+#define MXS_RTC_DEBUG 0xc0
+
+#define WDOG_TICK_RATE 1000 /* the watchdog uses a 1 kHz clock rate */
+
+struct imx28_wd {
+	struct watchdog wd;
+	void __iomem *regs;
+};
+
+#define to_imx28_wd(h) container_of(h, struct imx28_wd, wd)
+
+static int imx28_watchdog_set_timeout(struct watchdog *wd, unsigned timeout)
+{
+	struct imx28_wd *pwd = (struct imx28_wd *)to_imx28_wd(wd);
+	void __iomem *base;
+
+	if (timeout > (ULONG_MAX / WDOG_TICK_RATE))
+		return -EINVAL;
+
+	if (timeout) {
+		writel(timeout * WDOG_TICK_RATE, pwd->regs + MXS_RTC_WATCHDOG);
+		base = pwd->regs + MXS_RTC_SET_ADDR;
+	} else {
+		base = pwd->regs + MXS_RTC_CLR_ADDR;
+	}
+	writel(MXS_RTC_CTRL_WATCHDOGEN, base + MXS_RTC_CTRL);
+	writel(MXS_RTC_PERSISTENT1_FORCE_UPDATER, base + MXS_RTC_PERSISTENT1);
+
+	return 0;
+}
+
+static int imx28_wd_probe(struct device_d *dev)
+{
+	struct imx28_wd *priv;
+	int rc;
+
+	priv = xzalloc(sizeof(struct imx28_wd));
+	priv->regs = dev_request_mem_region(dev, 0);
+	priv->wd.set_timeout = imx28_watchdog_set_timeout;
+
+	if (!(readl(priv->regs + MXS_RTC_STAT) & MXS_RTC_STAT_WD_PRESENT)) {
+		rc = -ENODEV;
+		goto on_error;
+	}
+
+	/* disable the debug feature to ensure a working WD */
+	writel(0x00000000, priv->regs + MXS_RTC_DEBUG);
+
+	rc = watchdog_register(&priv->wd);
+	if (rc != 0)
+		goto on_error;
+
+	dev->priv = priv;
+	return 0;
+
+on_error:
+	free(priv);
+	return rc;
+}
+
+static void imx28_wd_remove(struct device_d *dev)
+{
+	struct imx28_wd *priv= dev->priv;
+	watchdog_deregister(&priv->wd);
+	free(priv);
+}
+
+static struct driver_d imx28_wd_driver = {
+	.name   = "im28wd",
+	.probe  = imx28_wd_probe,
+	.remove = imx28_wd_remove,
+};
+
+static int imx28_wd_init(void)
+{
+	register_driver(&imx28_wd_driver);
+	return 0;
+}
+
+device_initcall(imx28_wd_init);
-- 
1.7.10


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[PATCH 2/2] ARM/MXS: add a watchdog driver for i.MX28

[Juergen Beisert]

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
---
 drivers/watchdog/Kconfig  |    7 +++
 drivers/watchdog/Makefile |    1 +
 drivers/watchdog/im28wd.c |  121 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 129 insertions(+)
 create mode 100644 drivers/watchdog/im28wd.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index b5970c9..b1a73c0 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -7,4 +7,11 @@ if WATCHDOG
 config WATCHDOG_CORE
 	bool
 
+config WATCHDOG_MXS28
+	bool "i.MX28"
+	depends on ARCH_IMX28
+	select WATCHDOG_CORE
+	help
+	  Add support for watchdog management for the i.MX28 SoC.
+
 endif
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 7a446d7..b0d4d2a 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_WATCHDOG_CORE) += wd_core.o
+obj-$(CONFIG_WATCHDOG_MXS28) += im28wd.o
diff --git a/drivers/watchdog/im28wd.c b/drivers/watchdog/im28wd.c
new file mode 100644
index 0000000..b1c4809
--- /dev/null
+++ b/drivers/watchdog/im28wd.c
@@ -0,0 +1,121 @@
+/*
+ * (c) 2012 Juergen Beisert <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Note: this driver works for the i.MX28 SoC. It might work for the
+ * i.MX23 Soc as well, but is not tested yet.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <io.h>
+#include <errno.h>
+#include <malloc.h>
+
+#define MXS_RTC_CTRL 0x0
+#define MXS_RTC_SET_ADDR 0x4
+#define MXS_RTC_CLR_ADDR 0x8
+# define MXS_RTC_CTRL_WATCHDOGEN (1 << 4)
+
+#define MXS_RTC_STAT 0x10
+# define MXS_RTC_STAT_WD_PRESENT (1 << 29)
+
+#define MXS_RTC_WATCHDOG 0x50
+
+#define MXS_RTC_PERSISTENT0 0x60
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT0_EXT_RST (1 << 21)
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT0_THM_RST (1 << 20)
+
+#define MXS_RTC_PERSISTENT1 0x70
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT1_FORCE_UPDATER (1 << 31)
+
+#define MXS_RTC_DEBUG 0xc0
+
+#define WDOG_TICK_RATE 1000 /* the watchdog uses a 1 kHz clock rate */
+
+struct imx28_wd {
+	void __iomem *regs;
+	u32 timeout;
+};
+
+static struct imx28_wd *wd;
+
+/* note: 'timeout' in clock ticks */
+static void imx28_wd_set_timeout(const struct imx28_wd *p, unsigned timeout)
+{
+	void __iomem *base;
+
+	if (timeout) {
+		writel(timeout, p->regs + MXS_RTC_WATCHDOG);
+		base = p->regs + MXS_RTC_SET_ADDR;
+	} else {
+		base = p->regs + MXS_RTC_CLR_ADDR;
+	}
+	writel(MXS_RTC_CTRL_WATCHDOGEN, base + MXS_RTC_CTRL);
+	writel(MXS_RTC_PERSISTENT1_FORCE_UPDATER, base + MXS_RTC_PERSISTENT1);
+}
+
+/* note: 'timeout' in [seconds] */
+int watchdog_set_timeout(unsigned timeout)
+{
+	if (timeout > (ULONG_MAX / WDOG_TICK_RATE))
+		return -EINVAL;
+
+	imx28_wd_set_timeout(wd, timeout * WDOG_TICK_RATE);
+	return 0;
+}
+EXPORT_SYMBOL(watchdog_set_timeout);
+
+static int imx28_wd_probe(struct device_d *dev)
+{
+	struct imx28_wd *priv;
+
+	priv = xzalloc(sizeof(struct imx28_wd));
+	priv->regs = dev_request_mem_region(dev, 0);
+	priv->timeout = 20;
+	dev->priv = priv;
+	wd = priv;
+
+	if (!(readl(priv->regs + MXS_RTC_STAT) & MXS_RTC_STAT_WD_PRESENT)) {
+		free(priv);
+		return -ENODEV;
+	}
+
+	/* disable the debug feature to ensure a working WD */
+	writel(0x00000000, priv->regs + MXS_RTC_DEBUG);
+
+	return 0;
+}
+
+static void imx28_wd_remove(struct device_d *dev)
+{
+	struct imx28_wd *priv= dev->priv;
+	wd = NULL;
+	free(priv);
+}
+
+static struct driver_d imx28_wd_driver = {
+	.name   = "im28wd",
+	.probe  = imx28_wd_probe,
+	.remove = imx28_wd_remove,
+};
+
+static int imx28_wd_init(void)
+{
+	register_driver(&imx28_wd_driver);
+	return 0;
+}
+
+device_initcall(imx28_wd_init);
-- 
1.7.10


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[PATCH 2/2] ARM/MXS: add a watchdog driver for i.MX28

[Juergen Beisert]

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
---
 drivers/watchdog/Kconfig  |    7 +++
 drivers/watchdog/Makefile |    1 +
 drivers/watchdog/im28wd.c |  118 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 126 insertions(+)
 create mode 100644 drivers/watchdog/im28wd.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index b5970c9..b1a73c0 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -7,4 +7,11 @@ if WATCHDOG
 config WATCHDOG_CORE
 	bool
 
+config WATCHDOG_MXS28
+	bool "i.MX28"
+	depends on ARCH_IMX28
+	select WATCHDOG_CORE
+	help
+	  Add support for watchdog management for the i.MX28 SoC.
+
 endif
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 7a446d7..b0d4d2a 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_WATCHDOG_CORE) += wd_core.o
+obj-$(CONFIG_WATCHDOG_MXS28) += im28wd.o
diff --git a/drivers/watchdog/im28wd.c b/drivers/watchdog/im28wd.c
new file mode 100644
index 0000000..13d82a2
--- /dev/null
+++ b/drivers/watchdog/im28wd.c
@@ -0,0 +1,118 @@
+/*
+ * (c) 2012 Juergen Beisert <kernel@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Note: this driver works for the i.MX28 SoC. It might work for the
+ * i.MX23 Soc as well, but is not tested yet.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <io.h>
+#include <errno.h>
+#include <malloc.h>
+
+#define MXS_RTC_CTRL 0x0
+#define MXS_RTC_SET_ADDR 0x4
+#define MXS_RTC_CLR_ADDR 0x8
+# define MXS_RTC_CTRL_WATCHDOGEN (1 << 4)
+
+#define MXS_RTC_STAT 0x10
+# define MXS_RTC_STAT_WD_PRESENT (1 << 29)
+
+#define MXS_RTC_WATCHDOG 0x50
+
+#define MXS_RTC_PERSISTENT0 0x60
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT0_EXT_RST (1 << 21)
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT0_THM_RST (1 << 20)
+
+#define MXS_RTC_PERSISTENT1 0x70
+/* dubious meaning from inside the SoC's firmware ROM */
+# define MXS_RTC_PERSISTENT1_FORCE_UPDATER (1 << 31)
+
+#define MXS_RTC_DEBUG 0xc0
+
+#define WDOG_TICK_RATE 1000 /* the watchdog uses a 1 kHz clock rate */
+
+struct imx28_wd {
+	void __iomem *regs;
+	u32 timeout;
+};
+
+static struct imx28_wd *wd;
+
+/* note: 'timeout' in clock ticks */
+static void imx28_wd_set_timeout(const struct imx28_wd *p, unsigned timeout)
+{
+	void __iomem *base;
+
+	if (timeout) {
+		writel(timeout, p->regs + MXS_RTC_WATCHDOG);
+		base = p->regs + MXS_RTC_SET_ADDR;
+	} else {
+		base = p->regs + MXS_RTC_CLR_ADDR;
+	}
+	writel(MXS_RTC_CTRL_WATCHDOGEN, base + MXS_RTC_CTRL);
+	writel(MXS_RTC_PERSISTENT1_FORCE_UPDATER, base + MXS_RTC_PERSISTENT1);
+}
+
+/* note: 'timeout' in [seconds] */
+int watchdog_set_timeout(unsigned timeout)
+{
+	imx28_wd_set_timeout(wd, timeout * WDOG_TICK_RATE);
+	return 0;
+}
+EXPORT_SYMBOL(watchdog_set_timeout);
+
+static int imx28_wd_probe(struct device_d *dev)
+{
+	struct imx28_wd *priv;
+
+	priv = xzalloc(sizeof(struct imx28_wd));
+	priv->regs = dev_request_mem_region(dev, 0);
+	priv->timeout = 20;
+	dev->priv = priv;
+	wd = priv;
+
+	if (!(readl(priv->regs + MXS_RTC_STAT) & MXS_RTC_STAT_WD_PRESENT)) {
+		free(priv);
+		return -ENODEV;
+	}
+
+	/* disable the debug feature to ensure a working WD */
+	writel(0x00000000, priv->regs + MXS_RTC_DEBUG);
+
+	return 0;
+}
+
+static void imx28_wd_remove(struct device_d *dev)
+{
+	struct imx28_wd *priv= dev->priv;
+	wd = NULL;
+	free(priv);
+}
+
+static struct driver_d imx28_wd_driver = {
+	.name   = "im28wd",
+	.probe  = imx28_wd_probe,
+	.remove = imx28_wd_remove,
+};
+
+static int imx28_wd_init(void)
+{
+	register_driver(&imx28_wd_driver);
+	return 0;
+}
+
+device_initcall(imx28_wd_init);
-- 
1.7.10


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