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Subject[PATCH] Watchdog: DA9052/53 PMIC watchdog support v3
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Date
This driver adds support for the watchdog functionality provided by the Dialog
Semiconductor DA9052 PMIC chip.

Signed-off-by: Anthony Olech <Anthony.Olech@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
---
Changes since V3:
- Add new watchdog framework
Changes since V2:
- Code restructured for simplicty.
- Add watchdog documentation.
- Remove Auto strobing feature.
- Remove strobe filtering flag.
---
Documentation/watchdog/watchdog-parameters.txt | 3 +
drivers/watchdog/Kconfig | 7 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/da9052_wdt.c | 223 ++++++++++++++++++++++++
4 files changed, 234 insertions(+), 0 deletions(-)

diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt
index 17ddd82..b1a65eb 100644
--- a/Documentation/watchdog/watchdog-parameters.txt
+++ b/Documentation/watchdog/watchdog-parameters.txt
@@ -78,6 +78,9 @@ wd0_timeout: Default watchdog0 timeout in 1/10secs
wd1_timeout: Default watchdog1 timeout in 1/10secs
wd2_timeout: Default watchdog2 timeout in 1/10secs
-------------------------------------------------
+da9052_wdt:
+timeout: Watchdog timeout in seconds. 2<= timeout <=131, default=4.096s
+-------------------------------------------------
davinci_wdt:
heartbeat: Watchdog heartbeat period in seconds from 1 to 600, default 60
-------------------------------------------------
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index eeea76f..ece08cf 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -64,6 +64,13 @@ config SOFT_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called softdog.

+config DA9052_WATCHDOG
+ tristate "Dialog DA9052 Watchdog"
+ depends on PMIC_DA9052
+ select WATCHDOG_CORE
+ help
+ Support for the watchdog in the DA9052 PMIC.
+
config WM831X_WATCHDOG
tristate "WM831x watchdog"
depends on MFD_WM831X
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index e8f479a..b3032e9 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -167,3 +167,4 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
+obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
diff --git a/drivers/watchdog/da9052_wdt.c b/drivers/watchdog/da9052_wdt.c
new file mode 100644
index 0000000..ca7f907
--- /dev/null
+++ b/drivers/watchdog/da9052_wdt.c
@@ -0,0 +1,223 @@
+/*
+ * System monitoring driver for DA9052 PMICs.
+ *
+ * Copyright(c) 2012 Dialog Semiconductor Ltd.
+ *
+ * Author: Dajun Chen <dchen@diasemi.com>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/time.h>
+#include <linux/watchdog.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+
+#include <linux/mfd/da9052/reg.h>
+#include <linux/mfd/da9052/da9052.h>
+
+#define DA9052_DEF_TIMEOUT 4
+
+struct da9052_wdt_drvdata {
+ struct watchdog_device wdt;
+ struct da9052 *da9052;
+ struct mutex lock;
+};
+
+static const struct {
+ u8 reg_val;
+ int time; /* Seconds */
+} da9052_wdt_maps[] = {
+ { 1, 2 },
+ { 2, 4 },
+ { 3, 8 },
+ { 4, 16 },
+ { 5, 32 },
+ { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
+ { 6, 65 },
+ { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
+ { 7, 131 },
+};
+
+static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int timeout)
+{
+ struct da9052_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
+ struct da9052 *da9052 = driver_data->da9052;
+ int ret, i;
+
+ /* Disable the Watchdog timer before setting
+ * new time out.
+ */
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_TWDSCALE, 0);
+ if (ret < 0) {
+ dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
+ ret);
+ return ret;
+ }
+ if (timeout) {
+ /* To change the timeout, da9052 needs to
+ * be disabled for at least 150 us.
+ */
+ udelay(150);
+
+ /* Set the desired timeout */
+ for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
+ if (da9052_wdt_maps[i].time == timeout)
+ break;
+
+ if (i == ARRAY_SIZE(da9052_wdt_maps))
+ ret = -EINVAL;
+ else
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_TWDSCALE,
+ da9052_wdt_maps[i].reg_val);
+ if (ret < 0) {
+ dev_err(da9052->dev,
+ "Failed to update timescale bit, %d\n", ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int da9052_wdt_start(struct watchdog_device *wdt_dev)
+{
+ struct da9052_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
+ int ret = 0;
+
+ mutex_lock(&driver_data->lock);
+ ret = da9052_wdt_set_timeout(wdt_dev, DA9052_DEF_TIMEOUT);
+ mutex_unlock(&driver_data->lock);
+
+ return ret;
+}
+
+static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ struct da9052_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
+ struct da9052 *da9052 = driver_data->da9052;
+ int ret = 0;
+
+ mutex_lock(&driver_data->lock);
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_TWDSCALE, 0);
+ mutex_unlock(&driver_data->lock);
+
+ return ret;
+}
+
+static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
+{
+ struct da9052_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
+ struct da9052 *da9052 = driver_data->da9052;
+ int ret;
+
+ mutex_lock(&driver_data->lock);
+ /* Reset the watchdog timer */
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_WATCHDOG, 1 << 7);
+ if (ret < 0)
+ goto err_strobe;
+
+ /* FIXME: Reset the watchdog core, in general PMIC
+ * is supposed to do this
+ */
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_WATCHDOG, 0 << 7);
+err_strobe:
+ mutex_unlock(&driver_data->lock);
+ return ret;
+}
+
+static struct watchdog_info da9052_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = "DA9052 Watchdog",
+};
+
+static const struct watchdog_ops da9052_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = da9052_wdt_start,
+ .stop = da9052_wdt_stop,
+ .ping = da9052_wdt_ping,
+ .set_timeout = da9052_wdt_set_timeout,
+};
+
+
+static int __devinit da9052_wdt_probe(struct platform_device *pdev)
+{
+ struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
+ struct da9052_wdt_drvdata *driver_data;
+ struct watchdog_device *da9052_wdt;
+ int ret;
+
+ driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
+ GFP_KERNEL);
+ if (!driver_data) {
+ dev_err(da9052->dev, "Unable to alloacate watchdog device\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+ mutex_init(&driver_data->lock);
+ driver_data->da9052 = da9052;
+
+ da9052_wdt = &driver_data->wdt;
+
+ da9052_wdt->info = &da9052_wdt_info;
+ da9052_wdt->ops = &da9052_wdt_ops;
+ watchdog_set_drvdata(da9052_wdt, driver_data);
+
+ ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
+ DA9052_CONTROLD_TWDSCALE, 0);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n",
+ ret);
+ goto err;
+ }
+
+ ret = watchdog_register_device(&driver_data->wdt);
+ if (ret != 0) {
+ dev_err(da9052->dev, "watchdog_register_device() failed: %d\n",
+ ret);
+ goto err;
+ }
+
+ dev_set_drvdata(&pdev->dev, driver_data);
+err:
+ return ret;
+}
+
+static int __devexit da9052_wdt_remove(struct platform_device *pdev)
+{
+ struct da9052_wdt_drvdata *driver_data = dev_get_drvdata(&pdev->dev);
+
+ watchdog_unregister_device(&driver_data->wdt);
+
+ return 0;
+}
+
+static struct platform_driver da9052_wdt_driver = {
+ .probe = da9052_wdt_probe,
+ .remove = __devexit_p(da9052_wdt_remove),
+ .driver = {
+ .name = "da9052-watchdog",
+ },
+};
+
+module_platform_driver(da9052_wdt_driver);
+
+MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
+MODULE_DESCRIPTION("DA9052 SM Device Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9052-wdt");
+



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