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Diffstat (limited to '')
| -rw-r--r-- | drivers/watchdog/da9062_wdt.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c new file mode 100644 index 000000000..f02cbd530 --- /dev/null +++ b/drivers/watchdog/da9062_wdt.c @@ -0,0 +1,286 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Watchdog device driver for DA9062 and DA9061 PMICs + * Copyright (C) 2015 Dialog Semiconductor Ltd. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/watchdog.h> +#include <linux/platform_device.h> +#include <linux/uaccess.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/delay.h> +#include <linux/jiffies.h> +#include <linux/mfd/da9062/registers.h> +#include <linux/mfd/da9062/core.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/of.h> + +static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; +#define DA9062_TWDSCALE_DISABLE 0 +#define DA9062_TWDSCALE_MIN 1 +#define DA9062_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) +#define DA9062_WDT_MIN_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MIN] +#define DA9062_WDT_MAX_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX] +#define DA9062_WDG_DEFAULT_TIMEOUT wdt_timeout[DA9062_TWDSCALE_MAX-1] +#define DA9062_RESET_PROTECTION_MS 300 + +struct da9062_watchdog { + struct da9062 *hw; + struct watchdog_device wdtdev; + bool use_sw_pm; +}; + +static unsigned int da9062_wdt_read_timeout(struct da9062_watchdog *wdt) +{ + unsigned int val; + + regmap_read(wdt->hw->regmap, DA9062AA_CONTROL_D, &val); + + return wdt_timeout[val & DA9062AA_TWDSCALE_MASK]; +} + +static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs) +{ + unsigned int i; + + for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) { + if (wdt_timeout[i] >= secs) + return i; + } + + return DA9062_TWDSCALE_MAX; +} + +static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt) +{ + return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F, + DA9062AA_WATCHDOG_MASK, + DA9062AA_WATCHDOG_MASK); +} + +static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt, + unsigned int regval) +{ + struct da9062 *chip = wdt->hw; + + regmap_update_bits(chip->regmap, + DA9062AA_CONTROL_D, + DA9062AA_TWDSCALE_MASK, + DA9062_TWDSCALE_DISABLE); + + usleep_range(150, 300); + + return regmap_update_bits(chip->regmap, + DA9062AA_CONTROL_D, + DA9062AA_TWDSCALE_MASK, + regval); +} + +static int da9062_wdt_start(struct watchdog_device *wdd) +{ + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); + unsigned int selector; + int ret; + + selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout); + ret = da9062_wdt_update_timeout_register(wdt, selector); + if (ret) + dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n", + ret); + + return ret; +} + +static int da9062_wdt_stop(struct watchdog_device *wdd) +{ + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); + int ret; + + ret = regmap_update_bits(wdt->hw->regmap, + DA9062AA_CONTROL_D, + DA9062AA_TWDSCALE_MASK, + DA9062_TWDSCALE_DISABLE); + if (ret) + dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n", + ret); + + return ret; +} + +static int da9062_wdt_ping(struct watchdog_device *wdd) +{ + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); + int ret; + + /* + * Prevent pings from occurring late in system poweroff/reboot sequence + * and possibly locking out restart handler from accessing i2c bus. + */ + if (system_state > SYSTEM_RUNNING) + return 0; + + ret = da9062_reset_watchdog_timer(wdt); + if (ret) + dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n", + ret); + + return ret; +} + +static int da9062_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); + unsigned int selector; + int ret; + + selector = da9062_wdt_timeout_to_sel(timeout); + ret = da9062_wdt_update_timeout_register(wdt, selector); + if (ret) + dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n", + ret); + else + wdd->timeout = wdt_timeout[selector]; + + return ret; +} + +static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action, + void *data) +{ + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); + struct i2c_client *client = to_i2c_client(wdt->hw->dev); + int ret; + + /* Don't use regmap because it is not atomic safe */ + ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F, + DA9062AA_SHUTDOWN_MASK); + if (ret < 0) + dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n", + ret); + + /* wait for reset to assert... */ + mdelay(500); + + return ret; +} + +static const struct watchdog_info da9062_watchdog_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "DA9062 WDT", +}; + +static const struct watchdog_ops da9062_watchdog_ops = { + .owner = THIS_MODULE, + .start = da9062_wdt_start, + .stop = da9062_wdt_stop, + .ping = da9062_wdt_ping, + .set_timeout = da9062_wdt_set_timeout, + .restart = da9062_wdt_restart, +}; + +static const struct of_device_id da9062_compatible_id_table[] = { + { .compatible = "dlg,da9062-watchdog", }, + { }, +}; + +MODULE_DEVICE_TABLE(of, da9062_compatible_id_table); + +static int da9062_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + unsigned int timeout; + struct da9062 *chip; + struct da9062_watchdog *wdt; + + chip = dev_get_drvdata(dev->parent); + if (!chip) + return -EINVAL; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm"); + + wdt->hw = chip; + + wdt->wdtdev.info = &da9062_watchdog_info; + wdt->wdtdev.ops = &da9062_watchdog_ops; + wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT; + wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT; + wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS; + wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT; + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; + wdt->wdtdev.parent = dev; + + watchdog_set_restart_priority(&wdt->wdtdev, 128); + + watchdog_set_drvdata(&wdt->wdtdev, wdt); + dev_set_drvdata(dev, &wdt->wdtdev); + + timeout = da9062_wdt_read_timeout(wdt); + if (timeout) + wdt->wdtdev.timeout = timeout; + + /* Set timeout from DT value if available */ + watchdog_init_timeout(&wdt->wdtdev, 0, dev); + + if (timeout) { + da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout); + set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status); + } + + return devm_watchdog_register_device(dev, &wdt->wdtdev); +} + +static int __maybe_unused da9062_wdt_suspend(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); + + if (!wdt->use_sw_pm) + return 0; + + if (watchdog_active(wdd)) + return da9062_wdt_stop(wdd); + + return 0; +} + +static int __maybe_unused da9062_wdt_resume(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); + + if (!wdt->use_sw_pm) + return 0; + + if (watchdog_active(wdd)) + return da9062_wdt_start(wdd); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops, + da9062_wdt_suspend, da9062_wdt_resume); + +static struct platform_driver da9062_wdt_driver = { + .probe = da9062_wdt_probe, + .driver = { + .name = "da9062-watchdog", + .pm = &da9062_wdt_pm_ops, + .of_match_table = da9062_compatible_id_table, + }, +}; +module_platform_driver(da9062_wdt_driver); + +MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>"); +MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:da9062-watchdog"); 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