Initial support for watchdog block included in ROHM BD70528
power management IC.

Configurations for low power states are still to be checked.

Signed-off-by: Matti Vaittinen <matti.vaitti...@fi.rohmeurope.com>
---
 drivers/watchdog/Kconfig       |  12 +++
 drivers/watchdog/Makefile      |   1 +
 drivers/watchdog/bd70528_wdt.c | 187 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 200 insertions(+)
 create mode 100644 drivers/watchdog/bd70528_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 57f017d74a97..f30e3a3e886e 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -90,6 +90,18 @@ config SOFT_WATCHDOG_PRETIMEOUT
          watchdog. Be aware that governors might affect the watchdog because it
          is purely software, e.g. the panic governor will stall it!
 
+config BD70528_WATCHDOG
+       tristate "ROHM BD70528 PMIC Watchdog"
+       depends on MFD_ROHM_BD70528
+       select WATCHDOG_CORE
+       help
+         Support for the watchdog in the ROHM BD70528 PMIC. Watchdog trigger
+         cause system reset.
+
+         Say Y here to include support for the ROHM BD70528 watchdog.
+         Alternatively say M to compile the driver as a module,
+         which will be called bd70528_wdt.
+
 config DA9052_WATCHDOG
        tristate "Dialog DA9052 Watchdog"
        depends on PMIC_DA9052 || COMPILE_TEST
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index a0917ef28e07..1ce87a3b1172 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -204,6 +204,7 @@ obj-$(CONFIG_WATCHDOG_SUN4V)                += sun4v_wdt.o
 obj-$(CONFIG_XEN_WDT) += xen_wdt.o
 
 # Architecture Independent
+obj-$(CONFIG_BD70528_WATCHDOG) += bd70528_wdt.o
 obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
 obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o
 obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o
diff --git a/drivers/watchdog/bd70528_wdt.c b/drivers/watchdog/bd70528_wdt.c
new file mode 100644
index 000000000000..c24d4cce5e9c
--- /dev/null
+++ b/drivers/watchdog/bd70528_wdt.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 ROHM Semiconductors
+// ROHM BD70528MWV watchdog driver
+
+#include <linux/bcd.h>
+#include <linux/kernel.h>
+#include <linux/mfd/rohm-bd70528.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/watchdog.h>
+
+struct wdtbd70528 {
+       struct device *dev;
+       struct regmap *regmap;
+       struct mutex *rtc_lock;
+       struct watchdog_device wdt;
+};
+
+static int bd70528_wdt_set_locked(struct wdtbd70528 *w, int enable)
+{
+       struct bd70528 *bd70528;
+
+       bd70528 = container_of(w->rtc_lock, struct bd70528, rtc_timer_lock);
+       return bd70528->wdt_set(bd70528, enable, NULL);
+}
+static int bd70528_wdt_set(struct wdtbd70528 *w, int enable)
+{
+       int ret;
+
+       mutex_lock(w->rtc_lock);
+       ret = bd70528_wdt_set_locked(w, enable);
+       mutex_unlock(w->rtc_lock);
+
+       return ret;
+}
+
+static int bd70528_wdt_start(struct watchdog_device *wdt)
+{
+       struct wdtbd70528 *w = watchdog_get_drvdata(wdt);
+
+       dev_dbg(w->dev, "WDT ping...\n");
+       return bd70528_wdt_set(w, 1);
+}
+
+static int bd70528_wdt_stop(struct watchdog_device *wdt)
+{
+       struct wdtbd70528 *w = watchdog_get_drvdata(wdt);
+
+       dev_dbg(w->dev, "WDT stopping...\n");
+       return bd70528_wdt_set(w, 0);
+}
+
+static int bd70528_wdt_set_timeout(struct watchdog_device *wdt,
+                                   unsigned int timeout)
+{
+       unsigned int hours;
+       unsigned int minutes;
+       unsigned int seconds;
+       int ret;
+       struct wdtbd70528 *w = watchdog_get_drvdata(wdt);
+
+       seconds = timeout;
+       hours = timeout / (60 * 60);
+       /* Maximum timeout is 1h 59m 59s => hours is 1 or 0 */
+       if (hours)
+               seconds -= (60 * 60);
+       minutes = seconds / 60;
+       seconds = seconds % 60;
+
+       mutex_lock(w->rtc_lock);
+
+       ret = bd70528_wdt_set_locked(w, 0);
+       if (ret)
+               goto out_unlock;
+
+       ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_HOUR,
+                                BD70528_MASK_WDT_HOUR, hours);
+       if (ret) {
+               dev_err(w->dev, "Failed to set WDT hours\n");
+               goto out_en_unlock;
+       }
+       ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_MINUTE,
+                                BD70528_MASK_WDT_MINUTE, bin2bcd(minutes));
+       if (ret) {
+               dev_err(w->dev, "Failed to set WDT minutes\n");
+               goto out_en_unlock;
+       }
+       ret = regmap_update_bits(w->regmap, BD70528_REG_WDT_SEC,
+                                BD70528_MASK_WDT_SEC, bin2bcd(seconds));
+       if (ret)
+               dev_err(w->dev, "Failed to set WDT seconds\n");
+       else
+               dev_dbg(w->dev, "WDT tmo set to %u\n", timeout);
+
+out_en_unlock:
+       ret = bd70528_wdt_set_locked(w, 1);
+out_unlock:
+       mutex_unlock(w->rtc_lock);
+
+       return ret;
+}
+
+static const struct watchdog_info bd70528_wdt_info = {
+       .identity = "bd70528-wdt",
+       .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops bd70528_wdt_ops = {
+       .start          = bd70528_wdt_start,
+       .stop           = bd70528_wdt_stop,
+       .set_timeout    = bd70528_wdt_set_timeout,
+};
+
+/* Max time we can set is 1 hour, 59 minutes and 59 seconds */
+#define WDT_MAX_MS ((2 * 60 * 60 - 1) * 1000)
+/* Minimum time is 1 second */
+#define WDT_MIN_MS 1000
+#define DEFAULT_TIMEOUT 60
+
+static int bd70528_wdt_probe(struct platform_device *pdev)
+{
+       struct bd70528 *bd70528;
+       struct wdtbd70528 *w;
+       int ret;
+       unsigned int reg;
+
+       bd70528 = dev_get_drvdata(pdev->dev.parent);
+       if (!bd70528) {
+               dev_err(&pdev->dev, "No MFD driver data\n");
+               return -EINVAL;
+       }
+       w = devm_kzalloc(&pdev->dev, sizeof(*w), GFP_KERNEL);
+       if (!w)
+               return -ENOMEM;
+
+       w->regmap = bd70528->chip.regmap;
+       w->rtc_lock = &bd70528->rtc_timer_lock;
+       w->dev = &pdev->dev;
+
+       w->wdt.info = &bd70528_wdt_info;
+       w->wdt.ops =  &bd70528_wdt_ops;
+       w->wdt.min_hw_heartbeat_ms = WDT_MIN_MS;
+       w->wdt.max_hw_heartbeat_ms = WDT_MAX_MS;
+       w->wdt.parent = pdev->dev.parent;
+       w->wdt.timeout = DEFAULT_TIMEOUT;
+       watchdog_set_drvdata(&w->wdt, w);
+       watchdog_init_timeout(&w->wdt, 0, pdev->dev.parent);
+
+       ret = bd70528_wdt_set_timeout(&w->wdt, w->wdt.timeout);
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to set the watchdog timeout\n");
+               return ret;
+       }
+
+       mutex_lock(w->rtc_lock);
+       ret = regmap_read(w->regmap, BD70528_REG_WDT_CTRL, &reg);
+       mutex_unlock(w->rtc_lock);
+
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to get the watchdog state\n");
+               return ret;
+       }
+       if (reg & BD70528_MASK_WDT_EN) {
+               dev_dbg(&pdev->dev, "watchdog was running during probe\n");
+               set_bit(WDOG_HW_RUNNING, &w->wdt.status);
+       }
+
+       ret = devm_watchdog_register_device(&pdev->dev, &w->wdt);
+       if (ret < 0)
+               dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret);
+
+       return ret;
+}
+static struct platform_driver bd70528_wdt = {
+       .driver = {
+               .name = "bd70528-wdt"
+       },
+       .probe = bd70528_wdt_probe,
+};
+
+module_platform_driver(bd70528_wdt);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaitti...@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("BD70528 watchdog driver");
+MODULE_LICENSE("GPL");
-- 
2.14.3


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes.  Just then, he vanished ~~~

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