diff options
Diffstat (limited to 'kernel/drivers/watchdog/sunxi_wdt.c')
| -rw-r--r-- | kernel/drivers/watchdog/sunxi_wdt.c | 335 |
1 files changed, 335 insertions, 0 deletions
diff --git a/kernel/drivers/watchdog/sunxi_wdt.c b/kernel/drivers/watchdog/sunxi_wdt.c new file mode 100644 index 000000000..a29afb37c --- /dev/null +++ b/kernel/drivers/watchdog/sunxi_wdt.c @@ -0,0 +1,335 @@ +/* + * 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/delay.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/notifier.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/types.h> +#include <linux/watchdog.h> + +#define WDT_MAX_TIMEOUT 16 +#define WDT_MIN_TIMEOUT 1 +#define WDT_TIMEOUT_MASK 0x0F + +#define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1)) + +#define WDT_MODE_EN (1 << 0) + +#define DRV_NAME "sunxi-wdt" +#define DRV_VERSION "1.0" + +static bool nowayout = WATCHDOG_NOWAYOUT; +static unsigned int timeout = WDT_MAX_TIMEOUT; + +/* + * This structure stores the register offsets for different variants + * of Allwinner's watchdog hardware. + */ +struct sunxi_wdt_reg { + u8 wdt_ctrl; + u8 wdt_cfg; + u8 wdt_mode; + u8 wdt_timeout_shift; + u8 wdt_reset_mask; + u8 wdt_reset_val; +}; + +struct sunxi_wdt_dev { + struct watchdog_device wdt_dev; + void __iomem *wdt_base; + const struct sunxi_wdt_reg *wdt_regs; + struct notifier_block restart_handler; +}; + +/* + * wdt_timeout_map maps the watchdog timer interval value in seconds to + * the value of the register WDT_MODE at bits .wdt_timeout_shift ~ +3 + * + * [timeout seconds] = register value + * + */ + +static const int wdt_timeout_map[] = { + [1] = 0x1, /* 1s */ + [2] = 0x2, /* 2s */ + [3] = 0x3, /* 3s */ + [4] = 0x4, /* 4s */ + [5] = 0x5, /* 5s */ + [6] = 0x6, /* 6s */ + [8] = 0x7, /* 8s */ + [10] = 0x8, /* 10s */ + [12] = 0x9, /* 12s */ + [14] = 0xA, /* 14s */ + [16] = 0xB, /* 16s */ +}; + + +static int sunxi_restart_handle(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + struct sunxi_wdt_dev *sunxi_wdt = container_of(this, + struct sunxi_wdt_dev, + restart_handler); + void __iomem *wdt_base = sunxi_wdt->wdt_base; + const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs; + u32 val; + + /* Set system reset function */ + val = readl(wdt_base + regs->wdt_cfg); + val &= ~(regs->wdt_reset_mask); + val |= regs->wdt_reset_val; + writel(val, wdt_base + regs->wdt_cfg); + + /* Set lowest timeout and enable watchdog */ + val = readl(wdt_base + regs->wdt_mode); + val &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift); + val |= WDT_MODE_EN; + writel(val, wdt_base + regs->wdt_mode); + + /* + * Restart the watchdog. The default (and lowest) interval + * value for the watchdog is 0.5s. + */ + writel(WDT_CTRL_RELOAD, wdt_base + regs->wdt_ctrl); + + while (1) { + mdelay(5); + val = readl(wdt_base + regs->wdt_mode); + val |= WDT_MODE_EN; + writel(val, wdt_base + regs->wdt_mode); + } + return NOTIFY_DONE; +} + +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; + const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs; + + writel(WDT_CTRL_RELOAD, wdt_base + regs->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; + const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs; + u32 reg; + + if (wdt_timeout_map[timeout] == 0) + timeout++; + + sunxi_wdt->wdt_dev.timeout = timeout; + + reg = readl(wdt_base + regs->wdt_mode); + reg &= ~(WDT_TIMEOUT_MASK << regs->wdt_timeout_shift); + reg |= wdt_timeout_map[timeout] << regs->wdt_timeout_shift; + writel(reg, wdt_base + regs->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; + const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs; + + writel(0, wdt_base + regs->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; + const struct sunxi_wdt_reg *regs = sunxi_wdt->wdt_regs; + int ret; + + ret = sunxi_wdt_set_timeout(&sunxi_wdt->wdt_dev, + sunxi_wdt->wdt_dev.timeout); + if (ret < 0) + return ret; + + /* Set system reset function */ + reg = readl(wdt_base + regs->wdt_cfg); + reg &= ~(regs->wdt_reset_mask); + reg |= ~(regs->wdt_reset_val); + writel(reg, wdt_base + regs->wdt_cfg); + + /* Enable watchdog */ + reg = readl(wdt_base + regs->wdt_mode); + reg |= WDT_MODE_EN; + writel(reg, wdt_base + regs->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 const struct sunxi_wdt_reg sun4i_wdt_reg = { + .wdt_ctrl = 0x00, + .wdt_cfg = 0x04, + .wdt_mode = 0x04, + .wdt_timeout_shift = 3, + .wdt_reset_mask = 0x02, + .wdt_reset_val = 0x02, +}; + +static const struct sunxi_wdt_reg sun6i_wdt_reg = { + .wdt_ctrl = 0x10, + .wdt_cfg = 0x14, + .wdt_mode = 0x18, + .wdt_timeout_shift = 4, + .wdt_reset_mask = 0x03, + .wdt_reset_val = 0x01, +}; + +static const struct of_device_id sunxi_wdt_dt_ids[] = { + { .compatible = "allwinner,sun4i-a10-wdt", .data = &sun4i_wdt_reg }, + { .compatible = "allwinner,sun6i-a31-wdt", .data = &sun6i_wdt_reg }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sunxi_wdt_dt_ids); + +static int sunxi_wdt_probe(struct platform_device *pdev) +{ + struct sunxi_wdt_dev *sunxi_wdt; + const struct of_device_id *device; + 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); + + device = of_match_device(sunxi_wdt_dt_ids, &pdev->dev); + if (!device) + return -ENODEV; + + sunxi_wdt->wdt_regs = device->data; + + 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; + + sunxi_wdt->restart_handler.notifier_call = sunxi_restart_handle; + sunxi_wdt->restart_handler.priority = 128; + err = register_restart_handler(&sunxi_wdt->restart_handler); + if (err) + dev_err(&pdev->dev, + "cannot register restart handler (err=%d)\n", err); + + dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", + sunxi_wdt->wdt_dev.timeout, nowayout); + + return 0; +} + +static int sunxi_wdt_remove(struct platform_device *pdev) +{ + struct sunxi_wdt_dev *sunxi_wdt = platform_get_drvdata(pdev); + + unregister_restart_handler(&sunxi_wdt->restart_handler); + + 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 struct platform_driver sunxi_wdt_driver = { + .probe = sunxi_wdt_probe, + .remove = sunxi_wdt_remove, + .shutdown = sunxi_wdt_shutdown, + .driver = { + .name = DRV_NAME, + .of_match_table = 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); |