[PATCH v5] watchdog: Add DA9063 PMIC watchdog driver.

[PATCH v5] watchdog: Add DA9063 PMIC watchdog driver.

[Markus Pargmann]

From: Krystian Garbaciak <krystian.garbaciak@diasemi.com>

This driver supports the watchdog device inside the DA9063 PMIC.

Signed-off-by: Krystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---

Notes:
    Changes in v5:
     - Kconfig: Add note about the module name.
     - Change selector variables to int
     - Style fixes
     - use unsigned int to remove gcc verbose warning
     - Integrate _kick() and _disable() into the calling functions
    
    Changes in v4:
     - Fixed indentation
     - Fixed lock without unlock
     - Check for parent device and device driver data in probe(). If not present,
       this is an invalid prober initialization, return -EINVAL.
    
    Changes in v3:
     - Cleanup error handling for timeout selection and setting
     - Fix race condition due to late wdt drvdata setup
     - Remove static struct watchdog_device. It is not initialized in the probe
       function
     - Use WATCHDOG_NOWAYOUT_INIT_STATUS for the status
     - Remove 0 shift using DA9063_TWDSCALE_SHIFT

 drivers/watchdog/Kconfig      |   9 ++
 drivers/watchdog/Makefile     |   1 +
 drivers/watchdog/da9063_wdt.c | 222 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 232 insertions(+)
 create mode 100644 drivers/watchdog/da9063_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index c845527b503a..a92cbd7dce87 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -87,6 +87,15 @@ config DA9055_WATCHDOG
 	  This driver can also be built as a module.  If so, the module
 	  will be called da9055_wdt.
 
+config DA9063_WATCHDOG
+	tristate "Dialog DA9063 Watchdog"
+	depends on MFD_DA9063
+	select WATCHDOG_CORE
+	help
+	  Support for the watchdog in the DA9063 PMIC.
+
+	  This driver can be built as a module. The module name is da9063_wdt.
+
 config GPIO_WATCHDOG
 	tristate "Watchdog device controlled through GPIO-line"
 	depends on OF_GPIO
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 7b8a91ed20e7..ce4a7632d863 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -172,6 +172,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o
 # Architecture Independent
 obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
 obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o
+obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o
 obj-$(CONFIG_GPIO_WATCHDOG)	+= gpio_wdt.o
 obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
 obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
new file mode 100644
index 000000000000..b03b0a5b6f8b
--- /dev/null
+++ b/drivers/watchdog/da9063_wdt.c
@@ -0,0 +1,222 @@
+/*
+ * Watchdog driver for DA9063 PMICs.
+ *
+ * Copyright(c) 2012 Dialog Semiconductor Ltd.
+ *
+ * Author: Mariusz Wojtasik <mariusz.wojtasik@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/kernel.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/mfd/da9063/registers.h>
+#include <linux/mfd/da9063/core.h>
+#include <linux/regmap.h>
+
+/*
+ * Watchdog selector to timeout in seconds.
+ *   0: WDT disabled;
+ *   others: timeout = 2048 ms * 2^(TWDSCALE-1).
+ */
+static const int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
+#define DA9063_TWDSCALE_DISABLE		0
+#define DA9063_TWDSCALE_MIN		1
+#define DA9063_TWDSCALE_MAX		(ARRAY_SIZE(wdt_timeout) - 1)
+#define DA9063_WDT_MIN_TIMEOUT		wdt_timeout[DA9063_TWDSCALE_MIN]
+#define DA9063_WDT_MAX_TIMEOUT		wdt_timeout[DA9063_TWDSCALE_MAX]
+#define DA9063_WDG_TIMEOUT		wdt_timeout[3]
+
+struct da9063_watchdog {
+	struct da9063 *da9063;
+	struct watchdog_device wdtdev;
+	struct mutex lock;
+};
+
+static int da9063_wdt_timeout_to_sel(int secs)
+{
+	unsigned int i;
+
+	for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
+		if (wdt_timeout[i] >= secs)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
+{
+	return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
+			DA9063_TWDSCALE_MASK, regval);
+}
+
+static int da9063_wdt_start(struct watchdog_device *wdd)
+{
+	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
+	int selector;
+	int ret;
+
+	selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout);
+	if (selector < 0) {
+		dev_err(wdt->da9063->dev, "Timeout out of range (timeout=%d)\n",
+				wdt->wdtdev.timeout);
+		return selector;
+	}
+
+	mutex_lock(&wdt->lock);
+	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
+	if (ret) {
+		dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n",
+				ret);
+	}
+	mutex_unlock(&wdt->lock);
+
+	return ret;
+}
+
+static int da9063_wdt_stop(struct watchdog_device *wdd)
+{
+	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
+	int ret;
+
+	mutex_lock(&wdt->lock);
+	ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
+			DA9063_TWDSCALE_MASK,
+			DA9063_TWDSCALE_DISABLE);
+	if (ret)
+		dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n",
+				ret);
+	mutex_unlock(&wdt->lock);
+
+	return ret;
+}
+
+static int da9063_wdt_ping(struct watchdog_device *wdd)
+{
+	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
+	int ret;
+
+	mutex_lock(&wdt->lock);
+	ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F,
+			DA9063_WATCHDOG);
+	if (ret)
+		dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n",
+				ret);
+	mutex_unlock(&wdt->lock);
+
+	return ret;
+}
+
+static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
+		unsigned int timeout)
+{
+	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
+	int selector;
+	int ret;
+
+	selector = da9063_wdt_timeout_to_sel(timeout);
+	if (selector < 0) {
+		dev_err(wdt->da9063->dev,
+				"Unsupported watchdog timeout, should be between 2 and 131\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&wdt->lock);
+
+	ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
+	if (ret)
+		dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
+				ret);
+	else
+		wdd->timeout = wdt_timeout[selector];
+
+	mutex_unlock(&wdt->lock);
+
+	return ret;
+}
+
+static const struct watchdog_info da9063_watchdog_info = {
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity = "DA9063 Watchdog",
+};
+
+static const struct watchdog_ops da9063_watchdog_ops = {
+	.owner = THIS_MODULE,
+	.start = da9063_wdt_start,
+	.stop = da9063_wdt_stop,
+	.ping = da9063_wdt_ping,
+	.set_timeout = da9063_wdt_set_timeout,
+};
+
+static int da9063_wdt_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct da9063 *da9063;
+	struct da9063_watchdog *wdt;
+
+	if (!pdev->dev.parent)
+		return -EINVAL;
+
+	da9063 = dev_get_drvdata(pdev->dev.parent);
+	if (!da9063)
+		return -EINVAL;
+
+	wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	wdt->da9063 = da9063;
+	mutex_init(&wdt->lock);
+
+	wdt->wdtdev.info = &da9063_watchdog_info;
+	wdt->wdtdev.ops = &da9063_watchdog_ops;
+	wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT;
+	wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT;
+	wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT;
+
+	wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
+
+	watchdog_set_drvdata(&wdt->wdtdev, wdt);
+	dev_set_drvdata(&pdev->dev, wdt);
+
+	ret = watchdog_register_device(&wdt->wdtdev);
+	if (ret) {
+		dev_err(da9063->dev, "da9063-watchdog registration failed (err = %d)",
+				ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int da9063_wdt_remove(struct platform_device *pdev)
+{
+	struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev);
+
+	watchdog_unregister_device(&wdt->wdtdev);
+
+	return 0;
+}
+
+static struct platform_driver da9063_wdt_driver = {
+	.probe = da9063_wdt_probe,
+	.remove = da9063_wdt_remove,
+	.driver = {
+		.name = DA9063_DRVNAME_WATCHDOG,
+	},
+};
+module_platform_driver(da9063_wdt_driver);
+
+MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
+MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);
-- 
2.1.0.rc1

[PATCH v5] watchdog: Add DA9063 PMIC watchdog driver.

[Opensource [Steve Twiss]]

On 26 August 2014 07:26, Markus Pargmann wrote

> Subject: [PATCH v5] watchdog: Add DA9063 PMIC watchdog driver.
> 

[...]

> +
> +static int da9063_wdt_stop(struct watchdog_device *wdd)
> +{
> +	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
> +	int ret;
> +
> +	mutex_lock(&wdt->lock);
> +	ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
> +			DA9063_TWDSCALE_MASK,
> +			DA9063_TWDSCALE_DISABLE);
> +	if (ret)
> +		dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n",
> +				ret);
> +	mutex_unlock(&wdt->lock);
> +
> +	return ret;
> +}
> +

Hi Markus,

A quick typo.
ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
should probably be wdt->da9063->regmap

Regards,
Steve

[PATCH v5] watchdog: Add DA9063 PMIC watchdog driver.

[Markus Pargmann]

Hi Steve,

On Tue, Aug 26, 2014 at 03:21:53PM +0000, Opensource [Steve Twiss] wrote:
> 
> On 26 August 2014 07:26, Markus Pargmann wrote
> 
> > Subject: [PATCH v5] watchdog: Add DA9063 PMIC watchdog driver.
> > 
> 
> [...]
> 
> > +
> > +static int da9063_wdt_stop(struct watchdog_device *wdd)
> > +{
> > +	struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd);
> > +	int ret;
> > +
> > +	mutex_lock(&wdt->lock);
> > +	ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
> > +			DA9063_TWDSCALE_MASK,
> > +			DA9063_TWDSCALE_DISABLE);
> > +	if (ret)
> > +		dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n",
> > +				ret);
> > +	mutex_unlock(&wdt->lock);
> > +
> > +	return ret;
> > +}
> > +
> 
> Hi Markus,
> 
> A quick typo.
> ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
> should probably be wdt->da9063->regmap

yes, thank you. It seems I forgot to execute my checkpatch script before
sending. Sorry, will send a new version.

Best regards,

Markus

-- 
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[PATCH v5] watchdog: Add DA9063 PMIC watchdog driver.

[Opensource [Steve Twiss]]

On 27 August 2014 09:12 Markus Pargmann wrote:

> Hi Steve,
> On Tue, Aug 26, 2014 at 03:21:53PM +0000, Opensource [Steve Twiss] wrote:
> > On 26 August 2014 07:26, Markus Pargmann wrote
> > > Subject: [PATCH v5] watchdog: Add DA9063 PMIC watchdog driver.
> > >

[...]

> 
> [...] will send a new version.
> 
> Best regards,
> Markus

Thanks Markus,

Hopefully -- if time permits I am also able to run a couple of tests on the watchdog driver.
I will let you know the results as soon as I have them..

Regards,
Steve