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path: root/drivers/watchdog/pm8916_wdt.c
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Diffstat (limited to 'drivers/watchdog/pm8916_wdt.c')
-rw-r--r--drivers/watchdog/pm8916_wdt.c244
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/watchdog/pm8916_wdt.c b/drivers/watchdog/pm8916_wdt.c
new file mode 100644
index 000000000..0937b8d33
--- /dev/null
+++ b/drivers/watchdog/pm8916_wdt.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bitops.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/watchdog.h>
+
+#define PON_INT_RT_STS 0x10
+#define PMIC_WD_BARK_STS_BIT BIT(6)
+
+#define PON_PMIC_WD_RESET_S1_TIMER 0x54
+#define PON_PMIC_WD_RESET_S2_TIMER 0x55
+
+#define PON_PMIC_WD_RESET_S2_CTL 0x56
+#define RESET_TYPE_WARM 0x01
+#define RESET_TYPE_SHUTDOWN 0x04
+#define RESET_TYPE_HARD 0x07
+
+#define PON_PMIC_WD_RESET_S2_CTL2 0x57
+#define S2_RESET_EN_BIT BIT(7)
+
+#define PON_PMIC_WD_RESET_PET 0x58
+#define WATCHDOG_PET_BIT BIT(0)
+
+#define PM8916_WDT_DEFAULT_TIMEOUT 32
+#define PM8916_WDT_MIN_TIMEOUT 1
+#define PM8916_WDT_MAX_TIMEOUT 127
+
+struct pm8916_wdt {
+ struct regmap *regmap;
+ struct watchdog_device wdev;
+ u32 baseaddr;
+};
+
+static int pm8916_wdt_start(struct watchdog_device *wdev)
+{
+ struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
+
+ return regmap_update_bits(wdt->regmap,
+ wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL2,
+ S2_RESET_EN_BIT, S2_RESET_EN_BIT);
+}
+
+static int pm8916_wdt_stop(struct watchdog_device *wdev)
+{
+ struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
+
+ return regmap_update_bits(wdt->regmap,
+ wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL2,
+ S2_RESET_EN_BIT, 0);
+}
+
+static int pm8916_wdt_ping(struct watchdog_device *wdev)
+{
+ struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
+
+ return regmap_update_bits(wdt->regmap,
+ wdt->baseaddr + PON_PMIC_WD_RESET_PET,
+ WATCHDOG_PET_BIT, WATCHDOG_PET_BIT);
+}
+
+static int pm8916_wdt_configure_timers(struct watchdog_device *wdev)
+{
+ struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev);
+ int err;
+
+ err = regmap_write(wdt->regmap,
+ wdt->baseaddr + PON_PMIC_WD_RESET_S1_TIMER,
+ wdev->timeout - wdev->pretimeout);
+ if (err)
+ return err;
+
+ return regmap_write(wdt->regmap,
+ wdt->baseaddr + PON_PMIC_WD_RESET_S2_TIMER,
+ wdev->pretimeout);
+}
+
+static int pm8916_wdt_set_timeout(struct watchdog_device *wdev,
+ unsigned int timeout)
+{
+ wdev->timeout = timeout;
+
+ return pm8916_wdt_configure_timers(wdev);
+}
+
+static int pm8916_wdt_set_pretimeout(struct watchdog_device *wdev,
+ unsigned int pretimeout)
+{
+ wdev->pretimeout = pretimeout;
+
+ return pm8916_wdt_configure_timers(wdev);
+}
+
+static irqreturn_t pm8916_wdt_isr(int irq, void *arg)
+{
+ struct pm8916_wdt *wdt = arg;
+ int err, sts;
+
+ err = regmap_read(wdt->regmap, wdt->baseaddr + PON_INT_RT_STS, &sts);
+ if (err)
+ return IRQ_HANDLED;
+
+ if (sts & PMIC_WD_BARK_STS_BIT)
+ watchdog_notify_pretimeout(&wdt->wdev);
+
+ return IRQ_HANDLED;
+}
+
+static const struct watchdog_info pm8916_wdt_ident = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+ .identity = "QCOM PM8916 PON WDT",
+};
+
+static const struct watchdog_info pm8916_wdt_pt_ident = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE |
+ WDIOF_PRETIMEOUT,
+ .identity = "QCOM PM8916 PON WDT",
+};
+
+static const struct watchdog_ops pm8916_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = pm8916_wdt_start,
+ .stop = pm8916_wdt_stop,
+ .ping = pm8916_wdt_ping,
+ .set_timeout = pm8916_wdt_set_timeout,
+ .set_pretimeout = pm8916_wdt_set_pretimeout,
+};
+
+static int pm8916_wdt_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct pm8916_wdt *wdt;
+ struct device *parent;
+ int err, irq;
+
+ wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ parent = dev->parent;
+
+ /*
+ * The pm8916-pon-wdt is a child of the pon device, which is a child
+ * of the pm8916 mfd device. We want access to the pm8916 registers.
+ * Retrieve regmap from pm8916 (parent->parent) and base address
+ * from pm8916-pon (pon).
+ */
+ wdt->regmap = dev_get_regmap(parent->parent, NULL);
+ if (!wdt->regmap) {
+ dev_err(dev, "failed to locate regmap\n");
+ return -ENODEV;
+ }
+
+ err = device_property_read_u32(parent, "reg", &wdt->baseaddr);
+ if (err) {
+ dev_err(dev, "failed to get pm8916-pon address\n");
+ return err;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq > 0) {
+ err = devm_request_irq(dev, irq, pm8916_wdt_isr, 0,
+ "pm8916_wdt", wdt);
+ if (err)
+ return err;
+
+ wdt->wdev.info = &pm8916_wdt_pt_ident;
+ } else {
+ if (irq == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ wdt->wdev.info = &pm8916_wdt_ident;
+ }
+
+ /* Configure watchdog to hard-reset mode */
+ err = regmap_write(wdt->regmap,
+ wdt->baseaddr + PON_PMIC_WD_RESET_S2_CTL,
+ RESET_TYPE_HARD);
+ if (err) {
+ dev_err(dev, "failed configure watchdog\n");
+ return err;
+ }
+
+ wdt->wdev.ops = &pm8916_wdt_ops,
+ wdt->wdev.parent = dev;
+ wdt->wdev.min_timeout = PM8916_WDT_MIN_TIMEOUT;
+ wdt->wdev.max_timeout = PM8916_WDT_MAX_TIMEOUT;
+ wdt->wdev.timeout = PM8916_WDT_DEFAULT_TIMEOUT;
+ wdt->wdev.pretimeout = 0;
+ watchdog_set_drvdata(&wdt->wdev, wdt);
+ platform_set_drvdata(pdev, wdt);
+
+ watchdog_init_timeout(&wdt->wdev, 0, dev);
+ pm8916_wdt_configure_timers(&wdt->wdev);
+
+ return devm_watchdog_register_device(dev, &wdt->wdev);
+}
+
+static int __maybe_unused pm8916_wdt_suspend(struct device *dev)
+{
+ struct pm8916_wdt *wdt = dev_get_drvdata(dev);
+
+ if (watchdog_active(&wdt->wdev))
+ return pm8916_wdt_stop(&wdt->wdev);
+
+ return 0;
+}
+
+static int __maybe_unused pm8916_wdt_resume(struct device *dev)
+{
+ struct pm8916_wdt *wdt = dev_get_drvdata(dev);
+
+ if (watchdog_active(&wdt->wdev))
+ return pm8916_wdt_start(&wdt->wdev);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(pm8916_wdt_pm_ops, pm8916_wdt_suspend,
+ pm8916_wdt_resume);
+
+static const struct of_device_id pm8916_wdt_id_table[] = {
+ { .compatible = "qcom,pm8916-wdt" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, pm8916_wdt_id_table);
+
+static struct platform_driver pm8916_wdt_driver = {
+ .probe = pm8916_wdt_probe,
+ .driver = {
+ .name = "pm8916-wdt",
+ .of_match_table = of_match_ptr(pm8916_wdt_id_table),
+ .pm = &pm8916_wdt_pm_ops,
+ },
+};
+module_platform_driver(pm8916_wdt_driver);
+
+MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>");
+MODULE_DESCRIPTION("Qualcomm pm8916 watchdog driver");
+MODULE_LICENSE("GPL v2");