From: Yuechao Zhao <yuechao.zhao@xxxxxxxxxxxxxxxx> implement watchdong functionality into the "hwmon/nct7904.c" Signed-off-by: Yuechao Zhao <yuechao.zhao@xxxxxxxxxxxxxxxx> --- v4: - Set "wdt->timeout" to actual timeout - Modify nct7904_wdt_get_timeleft return value - Remove code 'i2c_set_clientdata(client, data)' v3: - Delete useless message(noise). - Delete useless variable 'ret'. - Delete 'ping_timeout'. - Use 'wdt->timeout' as basis for setting the chip timeout - Implement a get_timeout function - Use devm_watchdog_register_device() instead of watchdog_register_device(). - Use watchdog_stop_on_unregister() when driver remove. - Delete nct7904_remove() function. - Fix typos. v2: - Modify dependency of NC7904 into "drivers/hwmon/Kconfig". --- drivers/hwmon/Kconfig | 6 ++- drivers/hwmon/nct7904.c | 138 +++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 141 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 05a3083..cd0ae82 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1340,10 +1340,12 @@ config SENSORS_NCT7802 config SENSORS_NCT7904 tristate "Nuvoton NCT7904" - depends on I2C + depends on I2C && WATCHDOG + select WATCHDOG_CORE help If you say yes here you get support for the Nuvoton NCT7904 - hardware monitoring chip, including manual fan speed control. + hardware monitoring chip, including manual fan speed control + and support for the integrated watchdog. This driver can also be built as a module. If so, the module will be called nct7904. diff --git a/drivers/hwmon/nct7904.c b/drivers/hwmon/nct7904.c index 1f5743d..571a649 100644 --- a/drivers/hwmon/nct7904.c +++ b/drivers/hwmon/nct7904.c @@ -8,6 +8,9 @@ * Copyright (c) 2019 Advantech * Author: Amy.Shih <amy.shih@xxxxxxxxxxxxxxxx> * + * Copyright (c) 2020 Advantech + * Author: Yuechao Zhao <yuechao.zhao@xxxxxxxxxxxxxxxx> + * * Supports the following chips: * * Chip #vin #fan #pwm #temp #dts chip ID @@ -20,6 +23,7 @@ #include <linux/i2c.h> #include <linux/mutex.h> #include <linux/hwmon.h> +#include <linux/watchdog.h> #define VENDOR_ID_REG 0x7A /* Any bank */ #define NUVOTON_ID 0x50 @@ -87,18 +91,42 @@ #define FANCTL1_FMR_REG 0x00 /* Bank 3; 1 reg per channel */ #define FANCTL1_OUT_REG 0x10 /* Bank 3; 1 reg per channel */ +#define WDT_LOCK_REG 0xE0 /* W/O Lock Watchdog Register */ +#define WDT_EN_REG 0xE1 /* R/O Watchdog Enable Register */ +#define WDT_STS_REG 0xE2 /* R/O Watchdog Status Register */ +#define WDT_TIMER_REG 0xE3 /* R/W Watchdog Timer Register */ +#define WDT_SOFT_EN 0x55 /* Enable soft watchdog timer */ +#define WDT_SOFT_DIS 0xAA /* Disable soft watchdog timer */ + #define VOLT_MONITOR_MODE 0x0 #define THERMAL_DIODE_MODE 0x1 #define THERMISTOR_MODE 0x3 #define ENABLE_TSI BIT(1) +#define WATCHDOG_TIMEOUT 1 /* 1 minute default timeout */ + +/*The timeout range is 1-255 minutes*/ +#define MIN_TIMEOUT (1 * 60) +#define MAX_TIMEOUT (255 * 60) + +static int timeout = WATCHDOG_TIMEOUT; +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in minutes. 1 <= timeout <= 255, default=" + __MODULE_STRING(WATCHODOG_TIMEOUT) "."); + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + static const unsigned short normal_i2c[] = { 0x2d, 0x2e, I2C_CLIENT_END }; struct nct7904_data { struct i2c_client *client; + struct watchdog_device wdt; struct mutex bank_lock; int bank_sel; u32 fanin_mask; @@ -889,6 +917,95 @@ static int nct7904_detect(struct i2c_client *client, .info = nct7904_info, }; +/* + * Watchdog Function + */ +static int nct7904_wdt_start(struct watchdog_device *wdt) +{ + struct nct7904_data *data = watchdog_get_drvdata(wdt); + + /* Enable soft watchdog timer */ + return nct7904_write_reg(data, BANK_0, WDT_LOCK_REG, WDT_SOFT_EN); +} + +static int nct7904_wdt_stop(struct watchdog_device *wdt) +{ + struct nct7904_data *data = watchdog_get_drvdata(wdt); + + return nct7904_write_reg(data, BANK_0, WDT_LOCK_REG, WDT_SOFT_DIS); +} + +static int nct7904_wdt_set_timeout(struct watchdog_device *wdt, + unsigned int timeout) +{ + struct nct7904_data *data = watchdog_get_drvdata(wdt); + /* + * The NCT7904 is very special in watchdog function. + * Its minimum unit is minutes. And wdt->timeout needs + * to match the actual timeout selected. So, this needs + * to be: wdt->timeout = timeout / 60 * 60. + * For example, if the user configures a timeout of + * 119 seconds, the actual timeout will be 60 seconds. + * So, wdt->timeout must then be set to 60 seconds. + */ + wdt->timeout = timeout / 60 * 60; + + return nct7904_write_reg(data, BANK_0, WDT_TIMER_REG, + wdt->timeout / 60); +} + +static int nct7904_wdt_ping(struct watchdog_device *wdt) +{ + /* + * Note: + * NCT7904 does not support refreshing WDT_TIMER_REG register when + * the watchdog is active. Please disable watchdog before feeding + * the watchdog and enable it again. + */ + struct nct7904_data *data = watchdog_get_drvdata(wdt); + int ret; + + /* Disable soft watchdog timer */ + ret = nct7904_write_reg(data, BANK_0, WDT_LOCK_REG, WDT_SOFT_DIS); + if (ret < 0) + return ret; + + /* feed watchdog */ + ret = nct7904_write_reg(data, BANK_0, WDT_TIMER_REG, wdt->timeout / 60); + if (ret < 0) + return ret; + + /* Enable soft watchdog timer */ + return nct7904_write_reg(data, BANK_0, WDT_TIMER_REG, WDT_SOFT_EN); +} + +static unsigned int nct7904_wdt_get_timeleft(struct watchdog_device *wdt) +{ + struct nct7904_data *data = watchdog_get_drvdata(wdt); + int ret; + + ret = nct7904_read_reg(data, BANK_0, WDT_TIMER_REG); + if (ret < 0) + return 0; + + return ret * 60; +} + +static const struct watchdog_info nct7904_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, + .identity = "nct7904 watchdog", +}; + +static const struct watchdog_ops nct7904_wdt_ops = { + .owner = THIS_MODULE, + .start = nct7904_wdt_start, + .stop = nct7904_wdt_stop, + .ping = nct7904_wdt_ping, + .set_timeout = nct7904_wdt_set_timeout, + .get_timeleft = nct7904_wdt_get_timeleft, +}; + static int nct7904_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -1012,7 +1129,26 @@ static int nct7904_probe(struct i2c_client *client, hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, &nct7904_chip_info, NULL); - return PTR_ERR_OR_ZERO(hwmon_dev); + ret = PTR_ERR_OR_ZERO(hwmon_dev); + if (ret) + return ret; + + /* Watchdog initialization */ + data->wdt.ops = &nct7904_wdt_ops; + data->wdt.info = &nct7904_wdt_info; + + data->wdt.timeout = timeout * 60; /* in seconds */ + data->wdt.min_timeout = MIN_TIMEOUT; + data->wdt.max_timeout = MAX_TIMEOUT; + data->wdt.parent = &client->dev; + + watchdog_init_timeout(&data->wdt, timeout * 60, &client->dev); + watchdog_set_nowayout(&data->wdt, nowayout); + watchdog_set_drvdata(&data->wdt, data); + + watchdog_stop_on_unregister(&data->wdt); + + return devm_watchdog_register_device(dev, &data->wdt); } static const struct i2c_device_id nct7904_id[] = { -- 1.8.3.1