diff options
Diffstat (limited to 'drivers/watchdog/da9062_wdt.c')
| -rw-r--r-- | drivers/watchdog/da9062_wdt.c | 121 |
1 files changed, 87 insertions, 34 deletions
diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c index fe169d8e1fb2..426962547df1 100644 --- a/drivers/watchdog/da9062_wdt.c +++ b/drivers/watchdog/da9062_wdt.c @@ -11,10 +11,12 @@ #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> @@ -30,8 +32,18 @@ static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; 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; @@ -46,25 +58,15 @@ static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs) static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt) { - int ret; - - ret = regmap_update_bits(wdt->hw->regmap, - DA9062AA_CONTROL_F, - DA9062AA_WATCHDOG_MASK, - DA9062AA_WATCHDOG_MASK); - - return ret; + 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; - int ret; - - ret = da9062_reset_watchdog_timer(wdt); - if (ret) - return ret; regmap_update_bits(chip->regmap, DA9062AA_CONTROL_D, @@ -99,13 +101,6 @@ static int da9062_wdt_stop(struct watchdog_device *wdd) struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); int ret; - ret = da9062_reset_watchdog_timer(wdt); - if (ret) { - dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n", - ret); - return ret; - } - ret = regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_D, DA9062AA_TWDSCALE_MASK, @@ -122,6 +117,13 @@ 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", @@ -152,12 +154,22 @@ 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); + union i2c_smbus_data msg; int ret; - ret = regmap_write(wdt->hw->regmap, - DA9062AA_CONTROL_F, - DA9062AA_SHUTDOWN_MASK); - if (ret) + /* + * 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 be previously locked by some process unable to release the + * lock due to interrupts already being disabled at this late stage. + */ + msg.byte = DA9062AA_SHUTDOWN_MASK; + ret = __i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_WRITE, DA9062AA_CONTROL_F, + I2C_SMBUS_BYTE_DATA, &msg); + + if (ret < 0) dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n", ret); @@ -190,18 +202,21 @@ MODULE_DEVICE_TABLE(of, da9062_compatible_id_table); static int da9062_wdt_probe(struct platform_device *pdev) { - int ret; + struct device *dev = &pdev->dev; + unsigned int timeout; struct da9062 *chip; struct da9062_watchdog *wdt; - chip = dev_get_drvdata(pdev->dev.parent); + chip = dev_get_drvdata(dev->parent); if (!chip) return -EINVAL; - wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); + 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; @@ -211,26 +226,64 @@ static int da9062_wdt_probe(struct platform_device *pdev) 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 = &pdev->dev; + 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); - ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev); - if (ret < 0) { - dev_err(wdt->hw->dev, - "watchdog registration failed (%d)\n", ret); - return ret; + if (timeout) { + da9062_wdt_set_timeout(&wdt->wdtdev, wdt->wdtdev.timeout); + set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status); } - return da9062_wdt_ping(&wdt->wdtdev); + 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, }, }; |