^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Driver for watchdog device controlled through GPIO-line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Author: 2013, Alexander Shiyan <shc_work@mail.ru>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/gpio/consumer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/of.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/platform_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/watchdog.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) static bool nowayout = WATCHDOG_NOWAYOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) module_param(nowayout, bool, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) MODULE_PARM_DESC(nowayout,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) "Watchdog cannot be stopped once started (default="
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #define SOFT_TIMEOUT_MIN 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #define SOFT_TIMEOUT_DEF 60
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) enum {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) HW_ALGO_TOGGLE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) HW_ALGO_LEVEL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) struct gpio_wdt_priv {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct gpio_desc *gpiod;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) bool state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) bool always_running;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) unsigned int hw_algo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) struct watchdog_device wdd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) static void gpio_wdt_disable(struct gpio_wdt_priv *priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) /* Eternal ping */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) gpiod_set_value_cansleep(priv->gpiod, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) /* Put GPIO back to tristate */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) if (priv->hw_algo == HW_ALGO_TOGGLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) gpiod_direction_input(priv->gpiod);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) static int gpio_wdt_ping(struct watchdog_device *wdd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) switch (priv->hw_algo) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) case HW_ALGO_TOGGLE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) /* Toggle output pin */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) priv->state = !priv->state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) gpiod_set_value_cansleep(priv->gpiod, priv->state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) case HW_ALGO_LEVEL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) /* Pulse */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) gpiod_set_value_cansleep(priv->gpiod, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) udelay(1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) gpiod_set_value_cansleep(priv->gpiod, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) static int gpio_wdt_start(struct watchdog_device *wdd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) priv->state = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) gpiod_direction_output(priv->gpiod, priv->state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) set_bit(WDOG_HW_RUNNING, &wdd->status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) return gpio_wdt_ping(wdd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) static int gpio_wdt_stop(struct watchdog_device *wdd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) if (!priv->always_running) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) gpio_wdt_disable(priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) set_bit(WDOG_HW_RUNNING, &wdd->status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) static const struct watchdog_info gpio_wdt_ident = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) WDIOF_SETTIMEOUT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) .identity = "GPIO Watchdog",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) static const struct watchdog_ops gpio_wdt_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) .owner = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) .start = gpio_wdt_start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) .stop = gpio_wdt_stop,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) .ping = gpio_wdt_ping,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) static int gpio_wdt_probe(struct platform_device *pdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) struct device *dev = &pdev->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) struct device_node *np = dev->of_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) struct gpio_wdt_priv *priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) enum gpiod_flags gflags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) unsigned int hw_margin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) const char *algo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) if (!priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) platform_set_drvdata(pdev, priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) ret = of_property_read_string(np, "hw_algo", &algo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) if (!strcmp(algo, "toggle")) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) priv->hw_algo = HW_ALGO_TOGGLE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) gflags = GPIOD_IN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) } else if (!strcmp(algo, "level")) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) priv->hw_algo = HW_ALGO_LEVEL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) gflags = GPIOD_OUT_LOW;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) priv->gpiod = devm_gpiod_get(dev, NULL, gflags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) if (IS_ERR(priv->gpiod))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) return PTR_ERR(priv->gpiod);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) ret = of_property_read_u32(np,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) "hw_margin_ms", &hw_margin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) /* Disallow values lower than 2 and higher than 65535 ms */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) if (hw_margin < 2 || hw_margin > 65535)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) priv->always_running = of_property_read_bool(np,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) "always-running");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) watchdog_set_drvdata(&priv->wdd, priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) priv->wdd.info = &gpio_wdt_ident;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) priv->wdd.ops = &gpio_wdt_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) priv->wdd.min_timeout = SOFT_TIMEOUT_MIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) priv->wdd.max_hw_heartbeat_ms = hw_margin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) priv->wdd.parent = dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) priv->wdd.timeout = SOFT_TIMEOUT_DEF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) watchdog_init_timeout(&priv->wdd, 0, dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) watchdog_set_nowayout(&priv->wdd, nowayout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) watchdog_stop_on_reboot(&priv->wdd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) if (priv->always_running)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) gpio_wdt_start(&priv->wdd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) return devm_watchdog_register_device(dev, &priv->wdd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) static const struct of_device_id gpio_wdt_dt_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) { .compatible = "linux,wdt-gpio", },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) MODULE_DEVICE_TABLE(of, gpio_wdt_dt_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) static struct platform_driver gpio_wdt_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) .name = "gpio-wdt",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) .of_match_table = gpio_wdt_dt_ids,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) .probe = gpio_wdt_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) #ifdef CONFIG_GPIO_WATCHDOG_ARCH_INITCALL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) static int __init gpio_wdt_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) return platform_driver_register(&gpio_wdt_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) arch_initcall(gpio_wdt_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) module_platform_driver(gpio_wdt_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) MODULE_DESCRIPTION("GPIO Watchdog");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) MODULE_LICENSE("GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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