diff options
Diffstat (limited to 'target/linux/mcs814x/files-3.3/drivers/watchdog/mcs814x_wdt.c')
| -rw-r--r-- | target/linux/mcs814x/files-3.3/drivers/watchdog/mcs814x_wdt.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/target/linux/mcs814x/files-3.3/drivers/watchdog/mcs814x_wdt.c b/target/linux/mcs814x/files-3.3/drivers/watchdog/mcs814x_wdt.c new file mode 100644 index 000000000..ca69e8f95 --- /dev/null +++ b/target/linux/mcs814x/files-3.3/drivers/watchdog/mcs814x_wdt.c @@ -0,0 +1,207 @@ +/* + * Moschip MCS814x Watchdog driver + * + * Copyright (C) 2012, Florian Fainelli <florian@openwrt.org> + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/of.h> + +#define WDT_COUNT 0x00 +#define WDT_CTRL 0x04 +#define WDT_CTRL_EN 0x1 + +/* watchdog frequency */ +#define WDT_MAX_VALUE (0xffffffff) + +struct mcs814x_wdt { + void __iomem *regs; + spinlock_t lock; + struct watchdog_device wdt_dev; + struct clk *clk; +}; + +static int mcs814x_wdt_start(struct watchdog_device *dev) +{ + struct mcs814x_wdt *wdt = watchdog_get_drvdata(dev); + u32 reg; + + spin_lock(&wdt->lock); + reg = readl_relaxed(wdt->regs + WDT_CTRL); + reg |= WDT_CTRL_EN; + writel_relaxed(reg, wdt->regs + WDT_CTRL); + spin_unlock(&wdt->lock); + + return 0; +} + +static int mcs814x_wdt_stop(struct watchdog_device *dev) +{ + struct mcs814x_wdt *wdt = watchdog_get_drvdata(dev); + u32 reg; + + spin_lock(&wdt->lock); + reg = readl_relaxed(wdt->regs + WDT_CTRL); + reg &= ~WDT_CTRL_EN; + writel_relaxed(reg, wdt->regs + WDT_CTRL); + spin_unlock(&wdt->lock); + + return 0; +} + +static int mcs814x_wdt_set_timeout(struct watchdog_device *dev, + unsigned int new_timeout) +{ + struct mcs814x_wdt *wdt = watchdog_get_drvdata(dev); + + spin_lock(&wdt->lock); + /* watchdog counts upward and rollover (0xfffffff -> 0) + * triggers the reboot + */ + writel_relaxed(WDT_MAX_VALUE - (new_timeout * clk_get_rate(wdt->clk)), + wdt->regs + WDT_COUNT); + spin_unlock(&wdt->lock); + + return 0; +} + +static int mcs814x_wdt_ping(struct watchdog_device *dev) +{ + /* restart the watchdog */ + mcs814x_wdt_stop(dev); + mcs814x_wdt_set_timeout(dev, dev->timeout); + mcs814x_wdt_start(dev); + + return 0; +} + +static const struct watchdog_info mcs814x_wdt_ident = { + .options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, + .identity = "MCS814x Watchdog", +}; + +static struct watchdog_ops mcs814x_wdt_ops = { + .owner = THIS_MODULE, + .start = mcs814x_wdt_start, + .stop = mcs814x_wdt_stop, + .set_timeout = mcs814x_wdt_set_timeout, + .ping = mcs814x_wdt_ping, +}; + +static int __devinit mcs814x_wdt_probe(struct platform_device *pdev) +{ + struct resource *res; + struct mcs814x_wdt *wdt; + int ret; + struct clk *clk; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + clk = clk_get(NULL, "wdt"); + if (IS_ERR_OR_NULL(clk)) { + dev_err(&pdev->dev, "failed to get watchdog clock\n"); + return PTR_ERR(clk); + } + + wdt = kzalloc(sizeof(*wdt), GFP_KERNEL); + if (!wdt) { + ret = -ENOMEM; + goto out_clk; + } + + spin_lock_init(&wdt->lock); + wdt->clk = clk; + wdt->wdt_dev.info = &mcs814x_wdt_ident; + wdt->wdt_dev.ops = &mcs814x_wdt_ops; + wdt->wdt_dev.min_timeout = 1; + /* approximately 10995 secs */ + wdt->wdt_dev.max_timeout = (WDT_MAX_VALUE / clk_get_rate(clk)); + + platform_set_drvdata(pdev, wdt); + + /* only ioremap registers, because the register is shared */ + wdt->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res)); + if (!wdt->regs) { + ret = -ENOMEM; + goto out; + } + + watchdog_set_drvdata(&wdt->wdt_dev, wdt); + + ret = watchdog_register_device(&wdt->wdt_dev); + if (ret) { + dev_err(&pdev->dev, "cannot register watchdog: %d\n", ret); + goto out; + } + + dev_info(&pdev->dev, "registered\n"); + return 0; + +out: + platform_set_drvdata(pdev, NULL); + kfree(wdt); +out_clk: + clk_put(clk); + return ret; +} + +static int __devexit mcs814x_wdt_remove(struct platform_device *pdev) +{ + struct mcs814x_wdt *wdt = platform_get_drvdata(pdev); + + clk_put(wdt->clk); + watchdog_unregister_device(&wdt->wdt_dev); + watchdog_set_drvdata(&wdt->wdt_dev, NULL); + kfree(wdt); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static const struct of_device_id mcs814x_wdt_ids[] = { + { .compatible = "moschip,mcs814x-wdt", }, + { /* sentinel */ }, +}; + +static struct platform_driver mcs814x_wdt_driver = { + .driver = { + .name = "mcs814x-wdt", + .owner = THIS_MODULE, + .of_match_table = mcs814x_wdt_ids, + }, + .probe = mcs814x_wdt_probe, + .remove = __devexit_p(mcs814x_wdt_remove), +}; + +module_platform_driver(mcs814x_wdt_driver); + +MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); +MODULE_DESCRIPTION("Moschip MCS814x Watchdog driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); +MODULE_ALIAS("platform:mcs814x-wdt"); |