diff options
Diffstat (limited to 'drivers/watchdog/sunxi_wdt.c')
| -rw-r--r-- | drivers/watchdog/sunxi_wdt.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/drivers/watchdog/sunxi_wdt.c b/drivers/watchdog/sunxi_wdt.c new file mode 100644 index 000000000000..1f94b42764aa --- /dev/null +++ b/drivers/watchdog/sunxi_wdt.c @@ -0,0 +1,237 @@ +/* + * sunxi Watchdog Driver + * + * Copyright (c) 2013 Carlo Caione + * 2012 Henrik Nordstrom + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Based on xen_wdt.c + * (c) Copyright 2010 Novell, Inc. + */ + +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/types.h> +#include <linux/watchdog.h> + +#define WDT_MAX_TIMEOUT 16 +#define WDT_MIN_TIMEOUT 1 +#define WDT_MODE_TIMEOUT(n) ((n) << 3) +#define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F) + +#define WDT_CTRL 0x00 +#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1)) + +#define WDT_MODE 0x04 +#define WDT_MODE_EN (1 << 0) +#define WDT_MODE_RST_EN (1 << 1) + +#define DRV_NAME "sunxi-wdt" +#define DRV_VERSION "1.0" + +static bool nowayout = WATCHDOG_NOWAYOUT; +static unsigned int timeout = WDT_MAX_TIMEOUT; + +struct sunxi_wdt_dev { + struct watchdog_device wdt_dev; + void __iomem *wdt_base; +}; + +/* + * wdt_timeout_map maps the watchdog timer interval value in seconds to + * the value of the register WDT_MODE bit 3:6 + * + * [timeout seconds] = register value + * + */ + +static const int wdt_timeout_map[] = { + [1] = 0b0001, /* 1s */ + [2] = 0b0010, /* 2s */ + [3] = 0b0011, /* 3s */ + [4] = 0b0100, /* 4s */ + [5] = 0b0101, /* 5s */ + [6] = 0b0110, /* 6s */ + [8] = 0b0111, /* 8s */ + [10] = 0b1000, /* 10s */ + [12] = 0b1001, /* 12s */ + [14] = 0b1010, /* 14s */ + [16] = 0b1011, /* 16s */ +}; + +static int sunxi_wdt_ping(struct watchdog_device *wdt_dev) +{ + struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); + void __iomem *wdt_base = sunxi_wdt->wdt_base; + + iowrite32(WDT_CTRL_RELOAD, wdt_base + WDT_CTRL); + + return 0; +} + +static int sunxi_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int timeout) +{ + struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); + void __iomem *wdt_base = sunxi_wdt->wdt_base; + u32 reg; + + if (wdt_timeout_map[timeout] == 0) + timeout++; + + sunxi_wdt->wdt_dev.timeout = timeout; + + reg = ioread32(wdt_base + WDT_MODE); + reg &= ~WDT_TIMEOUT_MASK; + reg |= WDT_MODE_TIMEOUT(wdt_timeout_map[timeout]); + iowrite32(reg, wdt_base + WDT_MODE); + + sunxi_wdt_ping(wdt_dev); + + return 0; +} + +static int sunxi_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); + void __iomem *wdt_base = sunxi_wdt->wdt_base; + + iowrite32(0, wdt_base + WDT_MODE); + + return 0; +} + +static int sunxi_wdt_start(struct watchdog_device *wdt_dev) +{ + u32 reg; + struct sunxi_wdt_dev *sunxi_wdt = watchdog_get_drvdata(wdt_dev); + void __iomem *wdt_base = sunxi_wdt->wdt_base; + int ret; + + ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev, + sunxi_wdt->wdt_dev.timeout); + if (ret < 0) + return ret; + + reg = ioread32(wdt_base + WDT_MODE); + reg |= (WDT_MODE_RST_EN | WDT_MODE_EN); + iowrite32(reg, wdt_base + WDT_MODE); + + return 0; +} + +static const struct watchdog_info sunxi_wdt_info = { + .identity = DRV_NAME, + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops sunxi_wdt_ops = { + .owner = THIS_MODULE, + .start = sunxi_wdt_start, + .stop = sunxi_wdt_stop, + .ping = sunxi_wdt_ping, + .set_timeout = sunxi_wdt_set_timeout, +}; + +static int __init sunxi_wdt_probe(struct platform_device *pdev) +{ + struct sunxi_wdt_dev *sunxi_wdt; + struct resource *res; + int err; + + sunxi_wdt = devm_kzalloc(&pdev->dev, sizeof(*sunxi_wdt), GFP_KERNEL); + if (!sunxi_wdt) + return -EINVAL; + + platform_set_drvdata(pdev, sunxi_wdt); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + sunxi_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(sunxi_wdt->wdt_base)) + return PTR_ERR(sunxi_wdt->wdt_base); + + sunxi_wdt->wdt_dev.info = &sunxi_wdt_info; + sunxi_wdt->wdt_dev.ops = &sunxi_wdt_ops; + sunxi_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT; + sunxi_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT; + sunxi_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT; + sunxi_wdt->wdt_dev.parent = &pdev->dev; + + watchdog_init_timeout(&sunxi_wdt->wdt_dev, timeout, &pdev->dev); + watchdog_set_nowayout(&sunxi_wdt->wdt_dev, nowayout); + + watchdog_set_drvdata(&sunxi_wdt->wdt_dev, sunxi_wdt); + + sunxi_wdt_stop(&sunxi_wdt->wdt_dev); + + err = watchdog_register_device(&sunxi_wdt->wdt_dev); + if (unlikely(err)) + return err; + + dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", + sunxi_wdt->wdt_dev.timeout, nowayout); + + return 0; +} + +static int __exit sunxi_wdt_remove(struct platform_device *pdev) +{ + struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev); + + watchdog_unregister_device(&sunxi_wdt->wdt_dev); + watchdog_set_drvdata(&sunxi_wdt->wdt_dev, NULL); + + return 0; +} + +static void sunxi_wdt_shutdown(struct platform_device *pdev) +{ + struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev); + + sunxi_wdt_stop(&sunxi_wdt->wdt_dev); +} + +static const struct of_device_id sunxi_wdt_dt_ids[] = { + { .compatible = "allwinner,sun4i-wdt" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids); + +static struct platform_driver sunxi_wdt_driver = { + .probe = sunxi_wdt_probe, + .remove = sunxi_wdt_remove, + .shutdown = sunxi_wdt_shutdown, + .driver = { + .owner = THIS_MODULE, + .name = DRV_NAME, + .of_match_table = of_match_ptr(sunxi_wdt_dt_ids) + }, +}; + +module_platform_driver(sunxi_wdt_driver); + +module_param(timeout, uint, 0); +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>"); +MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>"); +MODULE_DESCRIPTION("sunxi WatchDog Timer Driver"); +MODULE_VERSION(DRV_VERSION); |