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228 lines
5.1 KiB
228 lines
5.1 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Watchdog driver for the A21 VME CPU Boards |
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* |
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* Copyright (C) 2013 MEN Mikro Elektronik Nuernberg GmbH |
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* |
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*/ |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/types.h> |
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#include <linux/kernel.h> |
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#include <linux/slab.h> |
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#include <linux/platform_device.h> |
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#include <linux/watchdog.h> |
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#include <linux/uaccess.h> |
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#include <linux/gpio/consumer.h> |
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#include <linux/delay.h> |
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#include <linux/bitops.h> |
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#include <linux/of.h> |
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#define NUM_GPIOS 6 |
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enum a21_wdt_gpios { |
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GPIO_WD_ENAB, |
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GPIO_WD_FAST, |
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GPIO_WD_TRIG, |
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GPIO_WD_RST0, |
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GPIO_WD_RST1, |
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GPIO_WD_RST2, |
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}; |
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struct a21_wdt_drv { |
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struct watchdog_device wdt; |
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struct gpio_desc *gpios[NUM_GPIOS]; |
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}; |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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static unsigned int a21_wdt_get_bootstatus(struct a21_wdt_drv *drv) |
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{ |
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int reset = 0; |
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reset |= gpiod_get_value(drv->gpios[GPIO_WD_RST0]) ? (1 << 0) : 0; |
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reset |= gpiod_get_value(drv->gpios[GPIO_WD_RST1]) ? (1 << 1) : 0; |
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reset |= gpiod_get_value(drv->gpios[GPIO_WD_RST2]) ? (1 << 2) : 0; |
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return reset; |
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} |
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static int a21_wdt_start(struct watchdog_device *wdt) |
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{ |
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struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt); |
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gpiod_set_value(drv->gpios[GPIO_WD_ENAB], 1); |
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return 0; |
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} |
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static int a21_wdt_stop(struct watchdog_device *wdt) |
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{ |
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struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt); |
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gpiod_set_value(drv->gpios[GPIO_WD_ENAB], 0); |
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return 0; |
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} |
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static int a21_wdt_ping(struct watchdog_device *wdt) |
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{ |
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struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt); |
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gpiod_set_value(drv->gpios[GPIO_WD_TRIG], 0); |
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ndelay(10); |
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gpiod_set_value(drv->gpios[GPIO_WD_TRIG], 1); |
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return 0; |
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} |
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static int a21_wdt_set_timeout(struct watchdog_device *wdt, |
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unsigned int timeout) |
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{ |
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struct a21_wdt_drv *drv = watchdog_get_drvdata(wdt); |
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if (timeout != 1 && timeout != 30) { |
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dev_err(wdt->parent, "Only 1 and 30 allowed as timeout\n"); |
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return -EINVAL; |
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} |
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if (timeout == 30 && wdt->timeout == 1) { |
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dev_err(wdt->parent, |
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"Transition from fast to slow mode not allowed\n"); |
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return -EINVAL; |
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} |
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if (timeout == 1) |
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gpiod_set_value(drv->gpios[GPIO_WD_FAST], 1); |
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else |
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gpiod_set_value(drv->gpios[GPIO_WD_FAST], 0); |
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wdt->timeout = timeout; |
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return 0; |
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} |
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static const struct watchdog_info a21_wdt_info = { |
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
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.identity = "MEN A21 Watchdog", |
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}; |
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static const struct watchdog_ops a21_wdt_ops = { |
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.owner = THIS_MODULE, |
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.start = a21_wdt_start, |
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.stop = a21_wdt_stop, |
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.ping = a21_wdt_ping, |
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.set_timeout = a21_wdt_set_timeout, |
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}; |
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static struct watchdog_device a21_wdt = { |
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.info = &a21_wdt_info, |
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.ops = &a21_wdt_ops, |
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.min_timeout = 1, |
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.max_timeout = 30, |
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}; |
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static int a21_wdt_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct a21_wdt_drv *drv; |
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unsigned int reset = 0; |
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int num_gpios; |
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int ret; |
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int i; |
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drv = devm_kzalloc(dev, sizeof(struct a21_wdt_drv), GFP_KERNEL); |
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if (!drv) |
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return -ENOMEM; |
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num_gpios = gpiod_count(dev, NULL); |
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if (num_gpios != NUM_GPIOS) { |
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dev_err(dev, "gpios DT property wrong, got %d want %d", |
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num_gpios, NUM_GPIOS); |
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return -ENODEV; |
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} |
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/* Request the used GPIOs */ |
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for (i = 0; i < num_gpios; i++) { |
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enum gpiod_flags gflags; |
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if (i < GPIO_WD_RST0) |
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gflags = GPIOD_ASIS; |
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else |
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gflags = GPIOD_IN; |
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drv->gpios[i] = devm_gpiod_get_index(dev, NULL, i, gflags); |
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if (IS_ERR(drv->gpios[i])) |
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return PTR_ERR(drv->gpios[i]); |
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gpiod_set_consumer_name(drv->gpios[i], "MEN A21 Watchdog"); |
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/* |
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* Retrieve the initial value from the GPIOs that should be |
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* output, then set up the line as output with that value. |
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*/ |
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if (i < GPIO_WD_RST0) { |
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int val; |
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val = gpiod_get_value(drv->gpios[i]); |
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gpiod_direction_output(drv->gpios[i], val); |
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} |
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} |
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watchdog_init_timeout(&a21_wdt, 30, dev); |
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watchdog_set_nowayout(&a21_wdt, nowayout); |
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watchdog_set_drvdata(&a21_wdt, drv); |
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a21_wdt.parent = dev; |
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reset = a21_wdt_get_bootstatus(drv); |
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if (reset == 2) |
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a21_wdt.bootstatus |= WDIOF_EXTERN1; |
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else if (reset == 4) |
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a21_wdt.bootstatus |= WDIOF_CARDRESET; |
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else if (reset == 5) |
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a21_wdt.bootstatus |= WDIOF_POWERUNDER; |
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else if (reset == 7) |
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a21_wdt.bootstatus |= WDIOF_EXTERN2; |
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drv->wdt = a21_wdt; |
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dev_set_drvdata(dev, drv); |
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ret = devm_watchdog_register_device(dev, &a21_wdt); |
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if (ret) |
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return ret; |
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dev_info(dev, "MEN A21 watchdog timer driver enabled\n"); |
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return 0; |
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} |
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static void a21_wdt_shutdown(struct platform_device *pdev) |
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{ |
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struct a21_wdt_drv *drv = dev_get_drvdata(&pdev->dev); |
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gpiod_set_value(drv->gpios[GPIO_WD_ENAB], 0); |
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} |
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static const struct of_device_id a21_wdt_ids[] = { |
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{ .compatible = "men,a021-wdt" }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, a21_wdt_ids); |
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static struct platform_driver a21_wdt_driver = { |
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.probe = a21_wdt_probe, |
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.shutdown = a21_wdt_shutdown, |
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.driver = { |
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.name = "a21-watchdog", |
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.of_match_table = a21_wdt_ids, |
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}, |
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}; |
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module_platform_driver(a21_wdt_driver); |
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MODULE_AUTHOR("MEN Mikro Elektronik"); |
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MODULE_DESCRIPTION("MEN A21 Watchdog"); |
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MODULE_LICENSE("GPL"); |
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MODULE_ALIAS("platform:a21-watchdog");
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