Add Ricoh RN5T568 PMIC based watchdog

Link: https://lore.barebox.org/20220118082122.73204-2-jbe@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 153 insertions, 0 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 70c8be7ca9..b8772e016f 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -109,6 +109,12 @@ config STPMIC1_WATCHDOG
 	help
 	  Enable to support configuration of the stpmic1's built-in watchdog.
 
+config RN568_WATCHDOG
+	bool "Ricoh RN5t568 PMIC based Watchdog"
+	depends on MFD_RN568PMIC
+	help
+	  Enable to support system control via the PMIC based watchdog.
+
 config F71808E_WDT
 	bool "Fintek F718xx, F818xx Super I/O Watchdog"
 	depends on X86
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 0d2f273f78..265ae179f1 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_ARCH_BCM283X) += bcm2835_wdt.o
 obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o
 obj-$(CONFIG_STM32_IWDG_WATCHDOG) += stm32_iwdg.o
 obj-$(CONFIG_STPMIC1_WATCHDOG) += stpmic1_wdt.o
+obj-$(CONFIG_RN568_WATCHDOG) += rn5t568_wdt.o
 obj-$(CONFIG_F71808E_WDT) += f71808e_wdt.o
 obj-$(CONFIG_GPIO_WATCHDOG) += gpio_wdt.o
 obj-$(CONFIG_ITCO_WDT) += itco_wdt.o
diff --git a/drivers/watchdog/rn5t568_wdt.c b/drivers/watchdog/rn5t568_wdt.c
new file mode 100644
index 0000000000..a6443609e2
--- /dev/null
+++ b/drivers/watchdog/rn5t568_wdt.c
@@ -0,0 +1,146 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Watchdog driver for Ricoh RN5T618 PMIC
+ *
+ * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
+ */
+
+#include <common.h>
+#include <init.h>
+#include <watchdog.h>
+#include <regmap.h>
+#include <of.h>
+
+#define RN5T568_WATCHDOG 0x0b
+# define RN5T568_WATCHDOG_WDPWROFFEN BIT(2)
+# define RN5T568_WATCHDOG_WDOGTIM_M (BIT(0) | BIT(1))
+#define RN5T568_PWRIREN 0x12
+# define RN5T568_PWRIREN_EN_WDOG BIT(6)
+#define RN5T568_PWRIRQ 0x13
+# define RN5T568_PWRIRQ_IR_WDOG BIT(6)
+
+struct rn5t568_wdt {
+	struct watchdog wdd;
+	struct regmap *regmap;
+	unsigned int timeout;
+};
+
+struct rn5t568_wdt_tim {
+	u8 reg_val;
+	u8 time;
+};
+
+static const struct rn5t568_wdt_tim rn5t568_wdt_timeout[] = {
+	{ .reg_val = 0, .time = 1, },
+	{ .reg_val = 1, .time = 8, },
+	{ .reg_val = 2, .time = 32, },
+	{ .reg_val = 3, .time = 128, },
+};
+
+#define PMIC_WDT_MAX_TIMEOUT 128
+
+static int rn5t568_wdt_start(struct regmap *regmap, int idx)
+{
+	int ret;
+
+	ret = regmap_update_bits(regmap, RN5T568_WATCHDOG, RN5T568_WATCHDOG_WDOGTIM_M,
+				 rn5t568_wdt_timeout[idx].reg_val);
+	if (ret)
+		return ret;
+
+	regmap_clear_bits(regmap, RN5T568_PWRIRQ, RN5T568_PWRIRQ_IR_WDOG);
+	regmap_set_bits(regmap, RN5T568_PWRIREN, RN5T568_PWRIREN_EN_WDOG);
+
+	pr_debug("RN5t: Starting the watchdog with %u seconds\n", rn5t568_wdt_timeout[idx].time);
+
+	return regmap_set_bits(regmap, RN5T568_WATCHDOG, RN5T568_WATCHDOG_WDPWROFFEN);
+}
+
+static int rn5t568_wdt_stop(struct regmap *regmap)
+{
+	int ret;
+
+	ret  = regmap_clear_bits(regmap, RN5T568_PWRIREN, RN5T568_PWRIREN_EN_WDOG);
+	if (ret)
+		return ret;
+
+	return regmap_clear_bits(regmap, RN5T568_WATCHDOG, RN5T568_WATCHDOG_WDPWROFFEN);
+}
+
+static int rn5t568_wdt_ping(struct regmap *regmap)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(regmap, RN5T568_WATCHDOG, &val);
+	if (ret)
+		return ret;
+
+	return regmap_write(regmap, RN5T568_WATCHDOG, val);
+}
+
+static int rn5t568_wdt_set_timeout(struct watchdog *wdd, unsigned int timeout)
+{
+	struct rn5t568_wdt *wdt = container_of(wdd, struct rn5t568_wdt, wdd);
+	int ret, i;
+
+	if (!timeout)
+		return rn5t568_wdt_stop(wdt->regmap);
+
+	for (i = 0; i < ARRAY_SIZE(rn5t568_wdt_timeout); i++) {
+		if (timeout < rn5t568_wdt_timeout[i].time)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(rn5t568_wdt_timeout))
+		return -EINVAL;
+
+	if (wdt->timeout == timeout)
+		return rn5t568_wdt_ping(wdt->regmap);
+
+	ret = rn5t568_wdt_start(wdt->regmap, i);
+	if (ret)
+		return ret;
+
+	wdt->timeout = rn5t568_wdt_timeout[i].time;
+
+	return ret;
+}
+
+static int rn5t568_wdt_probe(struct device_d *dev)
+{
+	struct rn5t568_wdt *wdt;
+	struct watchdog *wdd;
+	unsigned int val;
+	int ret;
+
+	wdt = xzalloc(sizeof(*wdt));
+
+	wdt->regmap = dev_get_regmap(dev->parent, NULL);
+	if (IS_ERR(wdt->regmap))
+		return PTR_ERR(wdt->regmap);
+
+	wdd = &wdt->wdd;
+	wdd->hwdev = dev;
+	wdd->set_timeout = rn5t568_wdt_set_timeout;
+	wdd->timeout_max = PMIC_WDT_MAX_TIMEOUT;
+
+	ret = regmap_read(wdt->regmap, RN5T568_WATCHDOG, &val);
+	if (ret == 0)
+		wdd->running = val & RN5T568_WATCHDOG_WDPWROFFEN ?
+			       WDOG_HW_RUNNING : WDOG_HW_NOT_RUNNING;
+
+	return watchdog_register(wdd);
+}
+
+static __maybe_unused const struct of_device_id rn5t568_wdt_of_match[] = {
+	{ .compatible = "ricoh,rn5t568-wdt" },
+	{ /* sentinel */ }
+};
+
+static struct driver_d rn5t568_wdt_driver = {
+	.name  = "rn5t568-wdt",
+	.probe = rn5t568_wdt_probe,
+	.of_compatible = DRV_OF_COMPAT(rn5t568_wdt_of_match),
+};
+device_platform_driver(rn5t568_wdt_driver);