diff options
Diffstat (limited to 'drivers/watchdog/da9063_wdt.c')
| -rw-r--r-- | drivers/watchdog/da9063_wdt.c | 213 |
1 files changed, 162 insertions, 51 deletions
diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c index 4691c5509129..92e1b78ff481 100644 --- a/drivers/watchdog/da9063_wdt.c +++ b/drivers/watchdog/da9063_wdt.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Watchdog driver for DA9063 PMICs. * @@ -5,10 +6,6 @@ * * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com> * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the - * Free Software Foundation; either version 2 of the License, or (at your - * option) any later version. */ #include <linux/kernel.h> @@ -17,9 +14,11 @@ #include <linux/platform_device.h> #include <linux/uaccess.h> #include <linux/slab.h> +#include <linux/i2c.h> #include <linux/delay.h> #include <linux/mfd/da9063/registers.h> #include <linux/mfd/da9063/core.h> +#include <linux/property.h> #include <linux/regmap.h> /* @@ -28,6 +27,7 @@ * others: timeout = 2048 ms * 2^(TWDSCALE-1). */ static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; + #define DA9063_TWDSCALE_DISABLE 0 #define DA9063_TWDSCALE_MIN 1 #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) @@ -36,11 +36,6 @@ static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; #define DA9063_WDG_TIMEOUT wdt_timeout[3] #define DA9063_RESET_PROTECTION_MS 256 -struct da9063_watchdog { - struct da9063 *da9063; - struct watchdog_device wdtdev; -}; - static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) { unsigned int i; @@ -53,22 +48,59 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) return DA9063_TWDSCALE_MAX; } -static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) +/* + * Read the currently active timeout. + * Zero means the watchdog is disabled. + */ +static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063) +{ + unsigned int val; + + regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val); + + return wdt_timeout[val & DA9063_TWDSCALE_MASK]; +} + +static int da9063_wdt_disable_timer(struct da9063 *da9063) +{ + return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, + DA9063_TWDSCALE_MASK, + DA9063_TWDSCALE_DISABLE); +} + +static int +da9063_wdt_update_timeout(struct da9063 *da9063, unsigned int timeout) { + unsigned int regval; + int ret; + + /* + * The watchdog triggers a reboot if a timeout value is already + * programmed because the timeout value combines two functions + * in one: indicating the counter limit and starting the watchdog. + * The watchdog must be disabled to be able to change the timeout + * value if the watchdog is already running. Then we can set the + * new timeout value which enables the watchdog again. + */ + ret = da9063_wdt_disable_timer(da9063); + if (ret) + return ret; + + usleep_range(150, 300); + regval = da9063_wdt_timeout_to_sel(timeout); + return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, DA9063_TWDSCALE_MASK, regval); } static int da9063_wdt_start(struct watchdog_device *wdd) { - struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); - unsigned int selector; + struct da9063 *da9063 = watchdog_get_drvdata(wdd); int ret; - selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); - ret = _da9063_wdt_set_timeout(wdt->da9063, selector); + ret = da9063_wdt_update_timeout(da9063, wdd->timeout); if (ret) - dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", + dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n", ret); return ret; @@ -76,13 +108,12 @@ static int da9063_wdt_start(struct watchdog_device *wdd) static int da9063_wdt_stop(struct watchdog_device *wdd) { - struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); + struct da9063 *da9063 = watchdog_get_drvdata(wdd); int ret; - ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, - DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); + ret = da9063_wdt_disable_timer(da9063); if (ret) - dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n", + dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n", ret); return ret; @@ -90,13 +121,20 @@ static int da9063_wdt_stop(struct watchdog_device *wdd) static int da9063_wdt_ping(struct watchdog_device *wdd) { - struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); + struct da9063 *da9063 = watchdog_get_drvdata(wdd); int ret; - ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, + /* + * 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 = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, DA9063_WATCHDOG); if (ret) - dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n", + dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n", ret); return ret; @@ -105,17 +143,27 @@ static int da9063_wdt_ping(struct watchdog_device *wdd) static int da9063_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { - struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); - unsigned int selector; - int ret; + struct da9063 *da9063 = watchdog_get_drvdata(wdd); + int ret = 0; + + /* + * There are two cases when a set_timeout() will be called: + * 1. The watchdog is off and someone wants to set the timeout for the + * further use. + * 2. The watchdog is already running and a new timeout value should be + * set. + * + * The watchdog can't store a timeout value not equal zero without + * enabling the watchdog, so the timeout must be buffered by the driver. + */ + if (watchdog_active(wdd)) + ret = da9063_wdt_update_timeout(da9063, timeout); - selector = da9063_wdt_timeout_to_sel(timeout); - ret = _da9063_wdt_set_timeout(wdt->da9063, selector); if (ret) - dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", + dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n", ret); else - wdd->timeout = wdt_timeout[selector]; + wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)]; return ret; } @@ -123,15 +171,29 @@ static int da9063_wdt_set_timeout(struct watchdog_device *wdd, static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action, void *data) { - struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); + struct da9063 *da9063 = watchdog_get_drvdata(wdd); + struct i2c_client *client = to_i2c_client(da9063->dev); + union i2c_smbus_data msg; int ret; - ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, - DA9063_SHUTDOWN); - if (ret) - dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n", + /* + * Don't use regmap because it is not atomic safe. Additionally, use + * unlocked flavor of i2c_smbus_xfer to avoid scenario where i2c bus + * might previously be locked by some process unable to release the + * lock due to interrupts already being disabled at this late stage. + */ + msg.byte = DA9063_SHUTDOWN; + ret = __i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_WRITE, DA9063_REG_CONTROL_F, + I2C_SMBUS_BYTE_DATA, &msg); + + if (ret < 0) + dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n", ret); + /* wait for reset to assert... */ + mdelay(500); + return ret; } @@ -151,43 +213,92 @@ static const struct watchdog_ops da9063_watchdog_ops = { static int da9063_wdt_probe(struct platform_device *pdev) { + struct device *dev = &pdev->dev; struct da9063 *da9063; - struct da9063_watchdog *wdt; + struct watchdog_device *wdd; + unsigned int timeout; - if (!pdev->dev.parent) + if (!dev->parent) return -EINVAL; - da9063 = dev_get_drvdata(pdev->dev.parent); + da9063 = dev_get_drvdata(dev->parent); if (!da9063) return -EINVAL; - wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); - if (!wdt) + wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL); + if (!wdd) return -ENOMEM; - wdt->da9063 = da9063; + da9063->use_sw_pm = device_property_present(dev, "dlg,use-sw-pm"); + + wdd->info = &da9063_watchdog_info; + wdd->ops = &da9063_watchdog_ops; + wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT; + wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT; + wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS; + wdd->parent = dev; + wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS; + + watchdog_set_restart_priority(wdd, 128); + watchdog_set_drvdata(wdd, da9063); + dev_set_drvdata(dev, wdd); + + wdd->timeout = DA9063_WDG_TIMEOUT; + + /* Use pre-configured timeout if watchdog is already running. */ + timeout = da9063_wdt_read_timeout(da9063); + if (timeout) + wdd->timeout = timeout; + + /* Set timeout, maybe override it with DT value, scale it */ + watchdog_init_timeout(wdd, 0, dev); + da9063_wdt_set_timeout(wdd, wdd->timeout); + + /* Update timeout if the watchdog is already running. */ + if (timeout) { + da9063_wdt_update_timeout(da9063, wdd->timeout); + set_bit(WDOG_HW_RUNNING, &wdd->status); + } + + return devm_watchdog_register_device(dev, wdd); +} + +static int da9063_wdt_suspend(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + struct da9063 *da9063 = watchdog_get_drvdata(wdd); - wdt->wdtdev.info = &da9063_watchdog_info; - wdt->wdtdev.ops = &da9063_watchdog_ops; - wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT; - wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT; - wdt->wdtdev.min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS; - wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT; - wdt->wdtdev.parent = &pdev->dev; + if (!da9063->use_sw_pm) + return 0; - wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; + if (watchdog_active(wdd)) + return da9063_wdt_stop(wdd); - watchdog_set_restart_priority(&wdt->wdtdev, 128); + return 0; +} + +static int da9063_wdt_resume(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + struct da9063 *da9063 = watchdog_get_drvdata(wdd); - watchdog_set_drvdata(&wdt->wdtdev, wdt); + if (!da9063->use_sw_pm) + return 0; - return devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev); + if (watchdog_active(wdd)) + return da9063_wdt_start(wdd); + + return 0; } +static DEFINE_SIMPLE_DEV_PM_OPS(da9063_wdt_pm_ops, da9063_wdt_suspend, + da9063_wdt_resume); + static struct platform_driver da9063_wdt_driver = { .probe = da9063_wdt_probe, .driver = { .name = DA9063_DRVNAME_WATCHDOG, + .pm = pm_sleep_ptr(&da9063_wdt_pm_ops), }, }; module_platform_driver(da9063_wdt_driver); |