From 84302c4c147d85081def63c489bc534aad58d5f9 Mon Sep 17 00:00:00 2001 From: Shubhi Garg Date: Thu, 16 Sep 2021 16:39:18 +0530 Subject: [PATCH] watchdog: max77851: add max77851 watchdog driver Bug 200749982 Change-Id: I29d5fec53b576cabce2c5dab975cc81ccf4a4e57 Signed-off-by: Shubhi Garg Reviewed-on: https://git-master.nvidia.com/r/c/linux-5.10/+/2595388 Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/2960844 Reviewed-by: Bitan Biswas Tested-by: Bitan Biswas GVS: Gerrit_Virtual_Submit --- drivers/watchdog/Makefile | 3 +- drivers/watchdog/max77851_wdt.c | 232 ++++++++++++++++++++++++++++++++ 2 files changed, 234 insertions(+), 1 deletion(-) create mode 100644 drivers/watchdog/max77851_wdt.c diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index d046a03e..ef807187 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 -# Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved. +# SPDX-FileCopyrightText: Copyright (c) 2022-2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved. obj-m += softdog-platform.o obj-m += watchdog-tegra-t18x.o +obj-m += max77851_wdt.o diff --git a/drivers/watchdog/max77851_wdt.c b/drivers/watchdog/max77851_wdt.c new file mode 100644 index 00000000..502e11f7 --- /dev/null +++ b/drivers/watchdog/max77851_wdt.c @@ -0,0 +1,232 @@ +// SPDX-License-Identifier: GPL-2.0 +// SPDX-FileCopyrightText: Copyright (c) 2022-2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved. +/* + * Maxim MAX77851 Watchdog Driver + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static bool nowayout = WATCHDOG_NOWAYOUT; + +struct max77851_wdt { + struct device *dev; + struct regmap *rmap; + struct watchdog_device wdt_dev; +}; + +static int max77851_wdt_start(struct watchdog_device *wdt_dev) +{ + struct max77851_wdt *wdt = watchdog_get_drvdata(wdt_dev); + + return regmap_update_bits(wdt->rmap, SYS_WD_CFG_REG, + SYS_WD_CFG_SYS_WD_EN, SYS_WD_CFG_SYS_WD_EN); +} + +static int max77851_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct max77851_wdt *wdt = watchdog_get_drvdata(wdt_dev); + + return regmap_update_bits(wdt->rmap, SYS_WD_CFG_REG, + SYS_WD_CFG_SYS_WD_EN, 0); +} + +static int max77851_wdt_ping(struct watchdog_device *wdt_dev) +{ + struct max77851_wdt *wdt = watchdog_get_drvdata(wdt_dev); + + return regmap_update_bits(wdt->rmap, SYS_WD_CLR_REG, + SYS_WD_CLR_SYS_WD_C, SYS_WD_CLR_COMMAND); +} + +static int max77851_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int timeout) +{ + struct max77851_wdt *wdt = watchdog_get_drvdata(wdt_dev); + unsigned int wdt_timeout; + u8 regval; + int ret; + + switch (timeout) { + case 0 ... 2: + regval = MAX77851_TWD_2_SEC; + wdt_timeout = 2; + break; + + case 3 ... 16: + regval = MAX77851_TWD_16_SEC; + wdt_timeout = 16; + break; + + case 17 ... 64: + regval = MAX77851_TWD_64_SEC; + wdt_timeout = 64; + break; + + default: + regval = MAX77851_TWD_128_SEC; + wdt_timeout = 128; + break; + } + + ret = regmap_update_bits(wdt->rmap, SYS_WD_CFG_REG, + SYS_WD_CLR_SYS_WD_C, SYS_WD_CLR_COMMAND); + + if (ret < 0) + return ret; + + ret = regmap_update_bits(wdt->rmap, SYS_WD_CFG_REG, + SYS_WD_CLR_SYS_WD_C, regval); + if (ret < 0) + return ret; + + wdt_dev->timeout = wdt_timeout; + + return 0; +} + +static const struct watchdog_info max77851_wdt_info = { + .identity = "max77851-watchdog", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops max77851_wdt_ops = { + .start = max77851_wdt_start, + .stop = max77851_wdt_stop, + .ping = max77851_wdt_ping, + .set_timeout = max77851_wdt_set_timeout, +}; + +static int max77851_wdt_probe(struct platform_device *pdev) +{ + struct max77851_wdt *wdt; + struct watchdog_device *wdt_dev; + struct device_node *np; + unsigned int regval; + int ret; + + np = of_get_child_by_name(pdev->dev.parent->of_node, "watchdog"); + if (np && !of_device_is_available(np)) + return -ENODEV; + + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->dev = &pdev->dev; + wdt->rmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!wdt->rmap) { + dev_err(wdt->dev, "Failed to get parent regmap\n"); + return -ENODEV; + } + + wdt_dev = &wdt->wdt_dev; + wdt_dev->info = &max77851_wdt_info; + wdt_dev->ops = &max77851_wdt_ops; + wdt_dev->min_timeout = 2; + wdt_dev->max_timeout = 128; + wdt_dev->max_hw_heartbeat_ms = 128 * 1000; + wdt_dev->parent = wdt->dev; + + platform_set_drvdata(pdev, wdt); + watchdog_set_drvdata(wdt_dev, wdt); + + /* Set WDT clear in OFF and sleep mode */ + ret = regmap_update_bits(wdt->rmap, SYS_WD_CFG_REG, + SYS_WD_CFG_SYS_WD_SLPC, SYS_WD_CFG_SYS_WD_SLPC); + if (ret < 0) { + dev_err(wdt->dev, "Failed to set WDT OFF mode: %d\n", ret); + return ret; + } + + /* start watchdog when "wdt-boot-init" flag is set */ + if (of_property_read_bool(np, "maxim,wdt-boot-init")) { + if (max77851_wdt_start(wdt_dev) < 0) + dev_err(wdt->dev, "Failed to start watchdog on booting\n"); + } + + /* Check if WDT running and if yes then set flags properly */ + ret = regmap_read(wdt->rmap, SYS_WD_CFG_REG, ®val); + if (ret < 0) { + dev_err(wdt->dev, "Failed to read WDT CFG register: %d\n", ret); + return ret; + } + + switch (regval & SYS_WD_CFG_SYS_WD) { + case MAX77851_TWD_2_SEC: + wdt_dev->timeout = 2; + break; + case MAX77851_TWD_16_SEC: + wdt_dev->timeout = 16; + break; + case MAX77851_TWD_64_SEC: + wdt_dev->timeout = 64; + break; + default: + wdt_dev->timeout = 128; + break; + } + + if (regval & SYS_WD_CFG_SYS_WD_EN) + set_bit(WDOG_HW_RUNNING, &wdt_dev->status); + + watchdog_set_nowayout(wdt_dev, nowayout); + + /* Stop watchdog on reboot */ + watchdog_stop_on_reboot(wdt_dev); + + ret = devm_watchdog_register_device(wdt->dev, wdt_dev); + if (ret < 0) { + dev_err(wdt->dev, "watchdog registration failed: %d\n", ret); + return ret; + } + + return 0; +} + +static int max77851_wdt_remove(struct platform_device *pdev) +{ + struct max77851_wdt *wdt = platform_get_drvdata(pdev); + + max77851_wdt_stop(&wdt->wdt_dev); + watchdog_unregister_device(&wdt->wdt_dev); + + return 0; +} + +static struct platform_device_id max77851_wdt_devtype[] = { + { .name = "max77851-watchdog", }, + { }, +}; + +static struct platform_driver max77851_wdt_driver = { + .driver = { + .name = "max77851-watchdog", + }, + .probe = max77851_wdt_probe, + .remove = max77851_wdt_remove, + .id_table = max77851_wdt_devtype, +}; + +module_platform_driver(max77851_wdt_driver); + +MODULE_DESCRIPTION("Max77851 watchdog timer driver"); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +MODULE_DESCRIPTION("MAX77851 watchdog driver"); +MODULE_AUTHOR("Shubhi Garg"); +MODULE_AUTHOR("Joan Na"); +MODULE_ALIAS("platform:max77851-watchdog"); +MODULE_LICENSE("GPL v2");