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author | Loic Poulain <loic.poulain@linaro.org> | 2018-11-23 09:44:36 +0100 |
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committer | Wim Van Sebroeck <wim@linux-watchdog.org> | 2018-12-22 12:15:33 +0100 |
commit | 969c0acc039f77c6b9d000ccb8b9d3afca4d3667 (patch) | |
tree | fc7f271da83b6bba70a4a2bd8ed928d21c877ad5 /drivers/watchdog/pm8916_wdt.c | |
parent | 4d9c6e90166f1a4b0132e8d8520a2fcd6d081e6b (diff) | |
download | linux-stable-969c0acc039f77c6b9d000ccb8b9d3afca4d3667.tar.gz linux-stable-969c0acc039f77c6b9d000ccb8b9d3afca4d3667.tar.bz2 linux-stable-969c0acc039f77c6b9d000ccb8b9d3afca4d3667.zip |
watchdog: Add pm8916 watchdog driver
The PM816 module is a versatile PMIC with many diverse functions
integrated, including, a watchdog.
This watchdog is subcomponent of the PON (Power On) peripheral,
in the same way as pwrkey/resin buttons.
It works with two timers (2-stages), the first one generates an
IRQ to the main SoC (APQ8016/MSM8916), the second one performs
the reset.
This driver expects the following device hierarchy:
[pm8916]->[pm8916-pon]->[pm8916-wdt]
It uses the pm8916 regmap to access PM8916 registers.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Diffstat (limited to 'drivers/watchdog/pm8916_wdt.c')
-rw-r--r-- | drivers/watchdog/pm8916_wdt.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/drivers/watchdog/pm8916_wdt.c b/drivers/watchdog/pm8916_wdt.c new file mode 100644 index 000000000000..7f10041fcf5b --- /dev/null +++ b/drivers/watchdog/pm8916_wdt.c @@ -0,0 +1,211 @@ +// 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 pm8916_wdt *wdt; + struct device *parent; + int err, irq; + + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + parent = pdev->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(&pdev->dev, "failed to locate regmap\n"); + return -ENODEV; + } + + err = device_property_read_u32(parent, "reg", &wdt->baseaddr); + if (err) { + dev_err(&pdev->dev, "failed to get pm8916-pon address\n"); + return err; + } + + irq = platform_get_irq(pdev, 0); + if (irq > 0) { + if (devm_request_irq(&pdev->dev, irq, pm8916_wdt_isr, 0, + "pm8916_wdt", wdt)) + irq = 0; + } + + /* 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(&pdev->dev, "failed configure watchdog\n"); + return err; + } + + wdt->wdev.info = (irq > 0) ? &pm8916_wdt_pt_ident : &pm8916_wdt_ident, + wdt->wdev.ops = &pm8916_wdt_ops, + wdt->wdev.parent = &pdev->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); + + watchdog_init_timeout(&wdt->wdev, 0, &pdev->dev); + pm8916_wdt_configure_timers(&wdt->wdev); + + return devm_watchdog_register_device(&pdev->dev, &wdt->wdev); +} + +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), + }, +}; +module_platform_driver(pm8916_wdt_driver); + +MODULE_AUTHOR("Loic Poulain <loic.poulain@linaro.org>"); +MODULE_DESCRIPTION("Qualcomm pm8916 watchdog driver"); +MODULE_LICENSE("GPL v2"); |