Re: [PATCH V2 3/4] watchdog: da9062: DA9062 watchdog driver
From: Guenter Roeck <hidden>
Date: 2015-05-15 02:13:25
Also in:
linux-input, linux-rtc, linux-watchdog, lkml
On 05/14/2015 09:43 AM, S Twiss wrote:
quoted hunk ↗ jump to hunk
From: S Twiss <redacted> Add watchdog driver support for DA9062 Signed-off-by: Steve Twiss <redacted> --- Changes in V2: - Removed informational dev_info() 'installed watchdog' message - Copyright headers GPL v2 (and later) match correct 'GPL' in MODULE_LICENSE - Removed the explicit 300 msecs delay from the reset_watchdog_timer() function and replaced it with a variable delay (depending on the difference since the last ping). A debug message is used to catch the multiple pings trying to break the 300 msecs protection barrier. - Fix error paths for the functions da9062_wdt_update_timeout_register() and da9062_wdt_stop() - Add error paths in the probe() and correctly clean-up the registered device if there is a problem after registration. This patch applies against linux-next and v4.1-rc3 drivers/watchdog/Kconfig | 9 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/da9062_wdt.c | 288 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 298 insertions(+) create mode 100644 drivers/watchdog/da9062_wdt.cdiff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index e5e7c55..dfdb6c6 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig@@ -96,6 +96,15 @@ config DA9063_WATCHDOG This driver can be built as a module. The module name is da9063_wdt. +config DA9062_WATCHDOG + tristate "Dialog DA9062 Watchdog" + depends on MFD_DA9062 + select WATCHDOG_CORE + help + Support for the watchdog in the DA9062 PMIC. + + This driver can be built as a module. The module name is da9062_wdt. + config GPIO_WATCHDOG tristate "Watchdog device controlled through GPIO-line" depends on OF_GPIOdiff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 5c19294..57ba815 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile@@ -179,6 +179,7 @@ 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_DA9062_WATCHDOG) += da9062_wdt.o obj-$(CONFIG_DA9063_WATCHDOG) += da9063_wdt.o obj-$(CONFIG_GPIO_WATCHDOG) += gpio_wdt.o obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.odiff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c new file mode 100644 index 0000000..9e6c93b --- /dev/null +++ b/drivers/watchdog/da9062_wdt.c@@ -0,0 +1,288 @@ +/* + * da9062_wdt.c - WDT device driver for DA9062 + * Copyright (C) 2015 Dialog Semiconductor Ltd. + * + * 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 <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/jiffies.h> +#include <linux/mfd/da9062/registers.h> +#include <linux/mfd/da9062/core.h> +#include <linux/regmap.h> +#include <linux/of.h> + +static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; +#define DA9062_TWDSCALE_DISABLE 0 +#define DA9062_TWDSCALE_MIN 1 +#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) +#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN] +#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX] +#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1] +#define DA9062_RESET_PROTECTION_MS 300 + +struct da9062_watchdog { + struct da9062 *hw; + struct watchdog_device wdtdev; + unsigned long j_time_stamp; +}; + +static void da9062_set_window_start(struct da9062_watchdog *wdt) +{ + wdt->j_time_stamp = jiffies; +} + +static void da9062_apply_window_protection(struct da9062_watchdog *wdt) +{ + unsigned long delay = msecs_to_jiffies(DA9062_RESET_PROTECTION_MS); + unsigned long timeout = wdt->j_time_stamp + delay; + unsigned long now = jiffies; + unsigned int diff_ms; + + /* if time-limit has not elapsed then wait for remainder */ + if (time_before(now, timeout)) { + diff_ms = jiffies_to_msecs(timeout-now); + dev_dbg(wdt->hw->dev, + "Kicked too quickly. Delaying %u msecs\n", diff_ms); + msleep(diff_ms); + } + + return;
Unnecessary return statement.
+}
+
+static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
+{
+ unsigned int i;
+
+ for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
+ if (wdt_timeout[i] >= secs)
+ return i;
+ }
+
+ return DA9062_TWDSCALE_MAX;
+}
+
+static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
+{
+ int ret;
+
+ da9062_apply_window_protection(wdt);
+
+ ret = regmap_update_bits(wdt->hw->regmap,
+ DA9062AA_CONTROL_F,
+ DA9062AA_WATCHDOG_MASK,
+ DA9062AA_WATCHDOG_MASK);
+
+ da9062_set_window_start(wdt);
+
+ return ret;
+}
+
+static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
+ unsigned int regval)
+{
+ struct da9062 *chip = wdt->hw;
+ int ret;
+
+ ret = da9062_reset_watchdog_timer(wdt);
+ if (ret) {
+ dev_err(chip->dev, "Failed to ping the watchdog (err = %d)\n",
+ ret);I am kind of torn about all this noisiness on error. Personally I would tend to ask people to let user space handle it, and not be that noisy in the kernel. Wim, any guidance ?
+ return ret; + } + + return regmap_update_bits(chip->regmap, + DA9062AA_CONTROL_D, + DA9062AA_TWDSCALE_MASK, + regval);
... and it is inconsistent - no error message here.
+}
+
+static int da9062_wdt_start(struct watchdog_device *wdd)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ unsigned int selector;
+ int ret;
+
+ selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
+ ret = da9062_wdt_update_timeout_register(wdt, selector);
+ if (ret)
+ dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
+ ret);
+
+ return ret;
+}
+
+static int da9062_wdt_stop(struct watchdog_device *wdd)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ int ret;
+
+ ret = da9062_reset_watchdog_timer(wdt);
+ if (ret) {
+ dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
+ ret);
+ return ret;
+ }
+
+ ret = regmap_update_bits(wdt->hw->regmap,
+ DA9062AA_CONTROL_D,
+ DA9062AA_TWDSCALE_MASK,
+ DA9062_TWDSCALE_DISABLE);
+ if (ret)
+ dev_alert(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
+ ret);.. and now we have an alert. Hmm..
+
+ return ret;
+}
+
+static int da9062_wdt_ping(struct watchdog_device *wdd)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ int ret;
+
+ dev_dbg(wdt->hw->dev, "watchdog ping\n");
+Is this really valuable enough to keep in the code ?
+ ret = da9062_reset_watchdog_timer(wdt);
+ if (ret)
+ dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
+ ret);
+
+ return ret;
+}
+
+static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
+ unsigned int timeout)
+{
+ struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
+ unsigned int selector;
+ int ret;
+
+ selector = da9062_wdt_timeout_to_sel(timeout);
+ ret = da9062_wdt_update_timeout_register(wdt, selector);
+ if (ret)
+ dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
+ ret);
+ else
+ wdd->timeout = wdt_timeout[selector];
+
+ return ret;
+}
+
+/* E_WDG_WARN interrupt handler */
+static irqreturn_t da9062_wdt_wdg_warn_irq_handler(int irq, void *data)
+{
+ struct da9062_watchdog *wdt = data;
+
+ dev_notice(wdt->hw->dev, "Watchdog timeout warning trigger.\n");
+ return IRQ_HANDLED;
+}
+
+static const struct watchdog_info da9062_watchdog_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = "DA9062 WDT",
+};
+
+static const struct watchdog_ops da9062_watchdog_ops = {
+ .owner = THIS_MODULE,
+ .start = da9062_wdt_start,
+ .stop = da9062_wdt_stop,
+ .ping = da9062_wdt_ping,
+ .set_timeout = da9062_wdt_set_timeout,
+};
+
+static int da9062_wdt_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct da9062 *chip;
+ struct da9062_watchdog *wdt;
+ int irq;
+
+ chip = dev_get_drvdata(pdev->dev.parent);
+ if (!chip)
+ return -EINVAL;
+
+ wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ wdt->hw = chip;
+
+ wdt->wdtdev.info = &da9062_watchdog_info;
+ wdt->wdtdev.ops = &da9062_watchdog_ops;
+ wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
+ wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
+ wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
+ wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
+
+ watchdog_set_drvdata(&wdt->wdtdev, wdt);
+ dev_set_drvdata(&pdev->dev, wdt);
+
+ irq = platform_get_irq_byname(pdev, "WDG_WARN");
+ if (irq < 0) {
+ dev_err(wdt->hw->dev, "Failed to get IRQ.\n");
+ ret = irq;
+ goto error;Just return; the label does not serve a useful purpose. Same for the other goto statements below. Also, is the interrupt mandatory ? All it does is to display a message. Looks very optional to me.
+ }
+
+ ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+ da9062_wdt_wdg_warn_irq_handler,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT | IRQF_SHARED,
+ "WDG_WARN", wdt);
+ if (ret) {
+ dev_err(wdt->hw->dev,
+ "Failed to request watchdog device IRQ.\n");
+ goto error;
+ }
+
+ ret = watchdog_register_device(&wdt->wdtdev);
+ if (ret < 0) {
+ dev_err(wdt->hw->dev,
+ "watchdog registration incomplete (%d)\n", ret);incomplete ? Should that be "failed" ?
+ goto error;
+ }
+
+ da9062_set_window_start(wdt);
+
+ ret = da9062_wdt_ping(&wdt->wdtdev);
+ if (ret < 0)
+ watchdog_unregister_device(&wdt->wdtdev);
+
+error:
+ return ret;
+}
+
+static int da9062_wdt_remove(struct platform_device *pdev)
+{
+ struct da9062_watchdog *wdt = dev_get_drvdata(&pdev->dev);
+
+ watchdog_unregister_device(&wdt->wdtdev);
+ return 0;
+}
+
+static struct platform_driver da9062_wdt_driver = {
+ .probe = da9062_wdt_probe,
+ .remove = da9062_wdt_remove,
+ .driver = {
+ .name = "da9062-watchdog",
+ },
+};
+module_platform_driver(da9062_wdt_driver);
+
+MODULE_AUTHOR("S Twiss [off-list ref]");
+MODULE_DESCRIPTION("WDT device driver for Dialog DA9062");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform: da9062-watchdog");Normally I don't see a space between "platform" and the driver name. Does this work ? Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html