diff options
Diffstat (limited to 'drivers/watchdog/pm8916_wdt.c')
| -rw-r--r-- | drivers/watchdog/pm8916_wdt.c | 244 |
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"); |