From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/watchdog/da9063_wdt.c | 308 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 308 insertions(+) create mode 100644 drivers/watchdog/da9063_wdt.c (limited to 'drivers/watchdog/da9063_wdt.c') diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c new file mode 100644 index 0000000000..684667469b --- /dev/null +++ b/drivers/watchdog/da9063_wdt.c @@ -0,0 +1,308 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Watchdog driver for DA9063 PMICs. + * + * Copyright(c) 2012 Dialog Semiconductor Ltd. + * + * Author: Mariusz Wojtasik + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Watchdog selector to timeout in seconds. + * 0: WDT disabled; + * others: timeout = 2048 ms * 2^(TWDSCALE-1). + */ +static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; +static bool use_sw_pm; + +#define DA9063_TWDSCALE_DISABLE 0 +#define DA9063_TWDSCALE_MIN 1 +#define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) +#define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] +#define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] +#define DA9063_WDG_TIMEOUT wdt_timeout[3] +#define DA9063_RESET_PROTECTION_MS 256 + +static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) +{ + unsigned int i; + + for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { + if (wdt_timeout[i] >= secs) + return i; + } + + return DA9063_TWDSCALE_MAX; +} + +/* + * 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 *da9063 = watchdog_get_drvdata(wdd); + int ret; + + ret = da9063_wdt_update_timeout(da9063, wdd->timeout); + if (ret) + dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n", + ret); + + return ret; +} + +static int da9063_wdt_stop(struct watchdog_device *wdd) +{ + struct da9063 *da9063 = watchdog_get_drvdata(wdd); + int ret; + + ret = da9063_wdt_disable_timer(da9063); + if (ret) + dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n", + ret); + + return ret; +} + +static int da9063_wdt_ping(struct watchdog_device *wdd) +{ + struct da9063 *da9063 = 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 = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, + DA9063_WATCHDOG); + if (ret) + dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n", + ret); + + return ret; +} + +static int da9063_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + 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); + + if (ret) + dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n", + ret); + else + wdd->timeout = wdt_timeout[da9063_wdt_timeout_to_sel(timeout)]; + + return ret; +} + +static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action, + void *data) +{ + struct da9063 *da9063 = watchdog_get_drvdata(wdd); + struct i2c_client *client = to_i2c_client(da9063->dev); + union i2c_smbus_data msg; + int 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 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; +} + +static const struct watchdog_info da9063_watchdog_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "DA9063 Watchdog", +}; + +static const struct watchdog_ops da9063_watchdog_ops = { + .owner = THIS_MODULE, + .start = da9063_wdt_start, + .stop = da9063_wdt_stop, + .ping = da9063_wdt_ping, + .set_timeout = da9063_wdt_set_timeout, + .restart = da9063_wdt_restart, +}; + +static int da9063_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct da9063 *da9063; + struct watchdog_device *wdd; + unsigned int timeout; + + if (!dev->parent) + return -EINVAL; + + da9063 = dev_get_drvdata(dev->parent); + if (!da9063) + return -EINVAL; + + wdd = devm_kzalloc(dev, sizeof(*wdd), GFP_KERNEL); + if (!wdd) + return -ENOMEM; + + 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 __maybe_unused da9063_wdt_suspend(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + if (!use_sw_pm) + return 0; + + if (watchdog_active(wdd)) + return da9063_wdt_stop(wdd); + + return 0; +} + +static int __maybe_unused da9063_wdt_resume(struct device *dev) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + if (!use_sw_pm) + return 0; + + if (watchdog_active(wdd)) + return da9063_wdt_start(wdd); + + return 0; +} + +static 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 = &da9063_wdt_pm_ops, + }, +}; +module_platform_driver(da9063_wdt_driver); + +MODULE_AUTHOR("Mariusz Wojtasik "); +MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); -- cgit v1.2.3