watchdog: da9062: DA9062 watchdog driver
authorS Twiss <stwiss.opensource@diasemi.com>
Thu, 28 May 2015 13:33:31 +0000 (14:33 +0100)
committerWim Van Sebroeck <wim@iguana.be>
Mon, 22 Jun 2015 13:54:34 +0000 (15:54 +0200)
Add watchdog driver support for DA9062

Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/Kconfig
drivers/watchdog/Makefile
drivers/watchdog/da9062_wdt.c [new file with mode: 0644]

index df936f5f5bb14bcedcd45ef5ca7d9315f4a72cd3..4a52e899fe05833796b5b6744404069fb62e8c76 100644 (file)
@@ -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_GPIO
index 4e26613a7f52b8a86926a1f9814e3e423a896ebf..59ea9a1b8e766f64e49531873cb5b94373956962 100644 (file)
@@ -181,6 +181,7 @@ 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.o
diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c
new file mode 100644 (file)
index 0000000..b3a870c
--- /dev/null
@@ -0,0 +1,253 @@
+/*
+ * 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);
+       }
+}
+
+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)
+               return ret;
+
+       return regmap_update_bits(chip->regmap,
+                                 DA9062AA_CONTROL_D,
+                                 DA9062AA_TWDSCALE_MASK,
+                                 regval);
+}
+
+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_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
+                       ret);
+
+       return ret;
+}
+
+static int da9062_wdt_ping(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;
+}
+
+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;
+}
+
+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;
+
+       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);
+
+       ret = watchdog_register_device(&wdt->wdtdev);
+       if (ret < 0) {
+               dev_err(wdt->hw->dev,
+                       "watchdog registration failed (%d)\n", ret);
+               return ret;
+       }
+
+       da9062_set_window_start(wdt);
+
+       ret = da9062_wdt_ping(&wdt->wdtdev);
+       if (ret < 0)
+               watchdog_unregister_device(&wdt->wdtdev);
+
+       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 <stwiss.opensource@diasemi.com>");
+MODULE_DESCRIPTION("WDT device driver for Dialog DA9062");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9062-watchdog");