|  | // SPDX-License-Identifier: GPL-2.0+ | 
|  | /* | 
|  | * Mellanox watchdog driver | 
|  | * | 
|  | * Copyright (C) 2019 Mellanox Technologies | 
|  | * Copyright (C) 2019 Michael Shych <[email protected]> | 
|  | */ | 
|  |  | 
|  | #include <linux/bitops.h> | 
|  | #include <linux/device.h> | 
|  | #include <linux/errno.h> | 
|  | #include <linux/log2.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/platform_data/mlxreg.h> | 
|  | #include <linux/platform_device.h> | 
|  | #include <linux/regmap.h> | 
|  | #include <linux/spinlock.h> | 
|  | #include <linux/types.h> | 
|  | #include <linux/watchdog.h> | 
|  |  | 
|  | #define MLXREG_WDT_CLOCK_SCALE		1000 | 
|  | #define MLXREG_WDT_MAX_TIMEOUT_TYPE1	32 | 
|  | #define MLXREG_WDT_MAX_TIMEOUT_TYPE2	255 | 
|  | #define MLXREG_WDT_MAX_TIMEOUT_TYPE3	65535 | 
|  | #define MLXREG_WDT_MIN_TIMEOUT		1 | 
|  | #define MLXREG_WDT_OPTIONS_BASE (WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | \ | 
|  | WDIOF_SETTIMEOUT) | 
|  |  | 
|  | /** | 
|  | * struct mlxreg_wdt - wd private data: | 
|  | * | 
|  | * @wdd:	watchdog device; | 
|  | * @device:	basic device; | 
|  | * @pdata:	data received from platform driver; | 
|  | * @regmap:	register map of parent device; | 
|  | * @timeout:	defined timeout in sec.; | 
|  | * @action_idx:	index for direct access to action register; | 
|  | * @timeout_idx:index for direct access to TO register; | 
|  | * @tleft_idx:	index for direct access to time left register; | 
|  | * @ping_idx:	index for direct access to ping register; | 
|  | * @reset_idx:	index for direct access to reset cause register; | 
|  | * @wd_type:	watchdog HW type; | 
|  | */ | 
|  | struct mlxreg_wdt { | 
|  | struct watchdog_device wdd; | 
|  | struct mlxreg_core_platform_data *pdata; | 
|  | void *regmap; | 
|  | int action_idx; | 
|  | int timeout_idx; | 
|  | int tleft_idx; | 
|  | int ping_idx; | 
|  | int reset_idx; | 
|  | int regmap_val_sz; | 
|  | enum mlxreg_wdt_type wdt_type; | 
|  | }; | 
|  |  | 
|  | static void mlxreg_wdt_check_card_reset(struct mlxreg_wdt *wdt) | 
|  | { | 
|  | struct mlxreg_core_data *reg_data; | 
|  | u32 regval; | 
|  | int rc; | 
|  |  | 
|  | if (wdt->reset_idx == -EINVAL) | 
|  | return; | 
|  |  | 
|  | if (!(wdt->wdd.info->options & WDIOF_CARDRESET)) | 
|  | return; | 
|  |  | 
|  | reg_data = &wdt->pdata->data[wdt->reset_idx]; | 
|  | rc = regmap_read(wdt->regmap, reg_data->reg, ®val); | 
|  | if (!rc) { | 
|  | if (regval & ~reg_data->mask) { | 
|  | wdt->wdd.bootstatus = WDIOF_CARDRESET; | 
|  | dev_info(wdt->wdd.parent, | 
|  | "watchdog previously reset the CPU\n"); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | static int mlxreg_wdt_start(struct watchdog_device *wdd) | 
|  | { | 
|  | struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd); | 
|  | struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->action_idx]; | 
|  |  | 
|  | return regmap_update_bits(wdt->regmap, reg_data->reg, ~reg_data->mask, | 
|  | BIT(reg_data->bit)); | 
|  | } | 
|  |  | 
|  | static int mlxreg_wdt_stop(struct watchdog_device *wdd) | 
|  | { | 
|  | struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd); | 
|  | struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->action_idx]; | 
|  |  | 
|  | return regmap_update_bits(wdt->regmap, reg_data->reg, ~reg_data->mask, | 
|  | ~BIT(reg_data->bit)); | 
|  | } | 
|  |  | 
|  | static int mlxreg_wdt_ping(struct watchdog_device *wdd) | 
|  | { | 
|  | struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd); | 
|  | struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->ping_idx]; | 
|  |  | 
|  | return regmap_write_bits(wdt->regmap, reg_data->reg, ~reg_data->mask, | 
|  | BIT(reg_data->bit)); | 
|  | } | 
|  |  | 
|  | static int mlxreg_wdt_set_timeout(struct watchdog_device *wdd, | 
|  | unsigned int timeout) | 
|  | { | 
|  | struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd); | 
|  | struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->timeout_idx]; | 
|  | u32 regval, set_time, hw_timeout; | 
|  | int rc; | 
|  |  | 
|  | switch (wdt->wdt_type) { | 
|  | case MLX_WDT_TYPE1: | 
|  | rc = regmap_read(wdt->regmap, reg_data->reg, ®val); | 
|  | if (rc) | 
|  | return rc; | 
|  |  | 
|  | hw_timeout = order_base_2(timeout * MLXREG_WDT_CLOCK_SCALE); | 
|  | regval = (regval & reg_data->mask) | hw_timeout; | 
|  | /* Rowndown to actual closest number of sec. */ | 
|  | set_time = BIT(hw_timeout) / MLXREG_WDT_CLOCK_SCALE; | 
|  | rc = regmap_write(wdt->regmap, reg_data->reg, regval); | 
|  | break; | 
|  | case MLX_WDT_TYPE2: | 
|  | set_time = timeout; | 
|  | rc = regmap_write(wdt->regmap, reg_data->reg, timeout); | 
|  | break; | 
|  | case MLX_WDT_TYPE3: | 
|  | /* WD_TYPE3 has 2B set time register */ | 
|  | set_time = timeout; | 
|  | if (wdt->regmap_val_sz == 1) { | 
|  | regval = timeout & 0xff; | 
|  | rc = regmap_write(wdt->regmap, reg_data->reg, regval); | 
|  | if (!rc) { | 
|  | regval = (timeout & 0xff00) >> 8; | 
|  | rc = regmap_write(wdt->regmap, | 
|  | reg_data->reg + 1, regval); | 
|  | } | 
|  | } else { | 
|  | rc = regmap_write(wdt->regmap, reg_data->reg, timeout); | 
|  | } | 
|  | break; | 
|  | default: | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | wdd->timeout = set_time; | 
|  | if (!rc) { | 
|  | /* | 
|  | * Restart watchdog with new timeout period | 
|  | * if watchdog is already started. | 
|  | */ | 
|  | if (watchdog_active(wdd)) { | 
|  | rc = mlxreg_wdt_stop(wdd); | 
|  | if (!rc) | 
|  | rc = mlxreg_wdt_start(wdd); | 
|  | } | 
|  | } | 
|  |  | 
|  | return rc; | 
|  | } | 
|  |  | 
|  | static unsigned int mlxreg_wdt_get_timeleft(struct watchdog_device *wdd) | 
|  | { | 
|  | struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd); | 
|  | struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->tleft_idx]; | 
|  | u32 regval, msb, lsb; | 
|  | int rc; | 
|  |  | 
|  | if (wdt->wdt_type == MLX_WDT_TYPE2) { | 
|  | rc = regmap_read(wdt->regmap, reg_data->reg, ®val); | 
|  | } else { | 
|  | /* WD_TYPE3 has 2 byte timeleft register */ | 
|  | if (wdt->regmap_val_sz == 1) { | 
|  | rc = regmap_read(wdt->regmap, reg_data->reg, &lsb); | 
|  | if (!rc) { | 
|  | rc = regmap_read(wdt->regmap, | 
|  | reg_data->reg + 1, &msb); | 
|  | regval = (msb & 0xff) << 8 | (lsb & 0xff); | 
|  | } | 
|  | } else { | 
|  | rc = regmap_read(wdt->regmap, reg_data->reg, ®val); | 
|  | } | 
|  | } | 
|  |  | 
|  | /* Return 0 timeleft in case of failure register read. */ | 
|  | return rc == 0 ? regval : 0; | 
|  | } | 
|  |  | 
|  | static const struct watchdog_ops mlxreg_wdt_ops_type1 = { | 
|  | .start		= mlxreg_wdt_start, | 
|  | .stop		= mlxreg_wdt_stop, | 
|  | .ping		= mlxreg_wdt_ping, | 
|  | .set_timeout	= mlxreg_wdt_set_timeout, | 
|  | .owner		= THIS_MODULE, | 
|  | }; | 
|  |  | 
|  | static const struct watchdog_ops mlxreg_wdt_ops_type2 = { | 
|  | .start		= mlxreg_wdt_start, | 
|  | .stop		= mlxreg_wdt_stop, | 
|  | .ping		= mlxreg_wdt_ping, | 
|  | .set_timeout	= mlxreg_wdt_set_timeout, | 
|  | .get_timeleft	= mlxreg_wdt_get_timeleft, | 
|  | .owner		= THIS_MODULE, | 
|  | }; | 
|  |  | 
|  | static const struct watchdog_info mlxreg_wdt_main_info = { | 
|  | .options	= MLXREG_WDT_OPTIONS_BASE | 
|  | | WDIOF_CARDRESET, | 
|  | .identity	= "mlx-wdt-main", | 
|  | }; | 
|  |  | 
|  | static const struct watchdog_info mlxreg_wdt_aux_info = { | 
|  | .options	= MLXREG_WDT_OPTIONS_BASE | 
|  | | WDIOF_ALARMONLY, | 
|  | .identity	= "mlx-wdt-aux", | 
|  | }; | 
|  |  | 
|  | static void mlxreg_wdt_config(struct mlxreg_wdt *wdt, | 
|  | struct mlxreg_core_platform_data *pdata) | 
|  | { | 
|  | struct mlxreg_core_data *data = pdata->data; | 
|  | int i; | 
|  |  | 
|  | wdt->reset_idx = -EINVAL; | 
|  | for (i = 0; i < pdata->counter; i++, data++) { | 
|  | if (strnstr(data->label, "action", sizeof(data->label))) | 
|  | wdt->action_idx = i; | 
|  | else if (strnstr(data->label, "timeout", sizeof(data->label))) | 
|  | wdt->timeout_idx = i; | 
|  | else if (strnstr(data->label, "timeleft", sizeof(data->label))) | 
|  | wdt->tleft_idx = i; | 
|  | else if (strnstr(data->label, "ping", sizeof(data->label))) | 
|  | wdt->ping_idx = i; | 
|  | else if (strnstr(data->label, "reset", sizeof(data->label))) | 
|  | wdt->reset_idx = i; | 
|  | } | 
|  |  | 
|  | wdt->pdata = pdata; | 
|  | if (strnstr(pdata->identity, mlxreg_wdt_main_info.identity, | 
|  | sizeof(mlxreg_wdt_main_info.identity))) | 
|  | wdt->wdd.info = &mlxreg_wdt_main_info; | 
|  | else | 
|  | wdt->wdd.info = &mlxreg_wdt_aux_info; | 
|  |  | 
|  | wdt->wdt_type = pdata->version; | 
|  | switch (wdt->wdt_type) { | 
|  | case MLX_WDT_TYPE1: | 
|  | wdt->wdd.ops = &mlxreg_wdt_ops_type1; | 
|  | wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE1; | 
|  | break; | 
|  | case MLX_WDT_TYPE2: | 
|  | wdt->wdd.ops = &mlxreg_wdt_ops_type2; | 
|  | wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2; | 
|  | break; | 
|  | case MLX_WDT_TYPE3: | 
|  | wdt->wdd.ops = &mlxreg_wdt_ops_type2; | 
|  | wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE3; | 
|  | break; | 
|  | default: | 
|  | break; | 
|  | } | 
|  |  | 
|  | wdt->wdd.min_timeout = MLXREG_WDT_MIN_TIMEOUT; | 
|  | } | 
|  |  | 
|  | static int mlxreg_wdt_init_timeout(struct mlxreg_wdt *wdt, | 
|  | struct mlxreg_core_platform_data *pdata) | 
|  | { | 
|  | u32 timeout; | 
|  |  | 
|  | timeout = pdata->data[wdt->timeout_idx].health_cntr; | 
|  | return mlxreg_wdt_set_timeout(&wdt->wdd, timeout); | 
|  | } | 
|  |  | 
|  | static int mlxreg_wdt_probe(struct platform_device *pdev) | 
|  | { | 
|  | struct device *dev = &pdev->dev; | 
|  | struct mlxreg_core_platform_data *pdata; | 
|  | struct mlxreg_wdt *wdt; | 
|  | int rc; | 
|  |  | 
|  | pdata = dev_get_platdata(dev); | 
|  | if (!pdata) { | 
|  | dev_err(dev, "Failed to get platform data.\n"); | 
|  | return -EINVAL; | 
|  | } | 
|  | wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); | 
|  | if (!wdt) | 
|  | return -ENOMEM; | 
|  |  | 
|  | wdt->wdd.parent = dev; | 
|  | wdt->regmap = pdata->regmap; | 
|  | rc = regmap_get_val_bytes(wdt->regmap); | 
|  | if (rc < 0) | 
|  | return -EINVAL; | 
|  |  | 
|  | wdt->regmap_val_sz = rc; | 
|  | mlxreg_wdt_config(wdt, pdata); | 
|  |  | 
|  | if ((pdata->features & MLXREG_CORE_WD_FEATURE_NOWAYOUT)) | 
|  | watchdog_set_nowayout(&wdt->wdd, WATCHDOG_NOWAYOUT); | 
|  | watchdog_stop_on_reboot(&wdt->wdd); | 
|  | watchdog_stop_on_unregister(&wdt->wdd); | 
|  | watchdog_set_drvdata(&wdt->wdd, wdt); | 
|  | rc = mlxreg_wdt_init_timeout(wdt, pdata); | 
|  | if (rc) | 
|  | goto register_error; | 
|  |  | 
|  | if ((pdata->features & MLXREG_CORE_WD_FEATURE_START_AT_BOOT)) { | 
|  | rc = mlxreg_wdt_start(&wdt->wdd); | 
|  | if (rc) | 
|  | goto register_error; | 
|  | set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); | 
|  | } | 
|  | mlxreg_wdt_check_card_reset(wdt); | 
|  | rc = devm_watchdog_register_device(dev, &wdt->wdd); | 
|  |  | 
|  | register_error: | 
|  | if (rc) | 
|  | dev_err(dev, "Cannot register watchdog device (err=%d)\n", rc); | 
|  | return rc; | 
|  | } | 
|  |  | 
|  | static struct platform_driver mlxreg_wdt_driver = { | 
|  | .probe	= mlxreg_wdt_probe, | 
|  | .driver	= { | 
|  | .name = "mlx-wdt", | 
|  | }, | 
|  | }; | 
|  |  | 
|  | module_platform_driver(mlxreg_wdt_driver); | 
|  |  | 
|  | MODULE_AUTHOR("Michael Shych <[email protected]>"); | 
|  | MODULE_DESCRIPTION("Mellanox watchdog driver"); | 
|  | MODULE_LICENSE("GPL"); | 
|  | MODULE_ALIAS("platform:mlx-wdt"); |