On 09/08/2014 06:58 AM, Markus Pargmann wrote:
From: Krystian Garbaciak <krystian.garbaciak@xxxxxxxxxxx>
This driver supports the watchdog device inside the DA9063 PMIC.
Signed-off-by: Krystian Garbaciak <krystian.garbaciak@xxxxxxxxxxx>
Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Markus Pargmann <mpa@xxxxxxxxxxxxxx>
---
Notes:
Changes in v6:
- Fix compile error
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 f57312fced80..669de63a7a48 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 468c3204c3b1..6c467a9821fe 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -173,6 +173,7 @@ 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..88441bdd2d1b
--- /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@xxxxxxxxxxx>
+ *
+ * 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);
Lucky you I am not the watchdog maintainer. For the hwmon drivers
I review I decided to enforce the "align continuation lines with '('"
rule after seeing the all-over-the-place indentation in this driver.
I know you explained it, but for me it is just confusing.
+}
+
+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);
We should have a rule that error messages which can only happen if there
is a bug in the code should never be permitted ;-).
Seriously, the watchdog subsystem enforces the range, so da9063_wdt_timeout_to_sel
can never return an error. Which really means that, in case you hit that unlikely
case that da9063_wdt_timeout_to_sel gets into the error condition anyway,
a WARN_ONCE and returning DA9063_TWDSCALE_MAX there would make much more sense
than all those repeated error checks.
I come to understand that you like error checks, but please keep in mind that all
you accomplish is to increase the size of the Linux kernel with no other benefit.
+ return selector;
+ }
+
+ mutex_lock(&wdt->lock);
Wonder if this came up with this driver, or with another one.
I don't see a value in all those locks. The watchdog subsystem
already provides locking.
+ ret = _da9063_wdt_set_timeout(wdt->da9063, selector);
+ if (ret) {
+ dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n",
+ ret);
+ }
Single statement does not need { }
+ 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(wdt->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);
The code here and in wdt_start is almost identical. Can you move it into
a single helper function, to be called with the timeout in seconds as
parameter ?
+
+ 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;
+
-ENODEV in both cases, please.
+ 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)",
da9063-watchdog is redundant with dev_err.
+ 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@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);
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