/* * drivers/watchdog/orion_wdt.c * * Watchdog driver for Orion/Kirkwood processors * * Author: Sylver Bruneau * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include /* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */ #define ORION_RSTOUT_MASK_OFFSET 0x20108 /* Internal registers can be configured at any 1 MiB aligned address */ #define INTERNAL_REGS_MASK ~(SZ_1M - 1) /* * Watchdog timer block registers. */ #define TIMER_CTRL 0x0000 #define WDT_EN 0x0010 #define WDT_VAL 0x0024 #define WDT_MAX_CYCLE_COUNT 0xffffffff #define WDT_RESET_OUT_EN BIT(1) static bool nowayout = WATCHDOG_NOWAYOUT; static int heartbeat = -1; /* module parameter (seconds) */ struct orion_watchdog { struct watchdog_device wdt; void __iomem *reg; void __iomem *rstout; unsigned long clk_rate; struct clk *clk; }; static int orion_wdt_ping(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); /* Reload watchdog duration */ writel(dev->clk_rate * wdt_dev->timeout, dev->reg + WDT_VAL); return 0; } static int orion_wdt_start(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); /* Set watchdog duration */ writel(dev->clk_rate * wdt_dev->timeout, dev->reg + WDT_VAL); /* Enable watchdog timer */ atomic_io_modify(dev->reg + TIMER_CTRL, WDT_EN, WDT_EN); /* Enable reset on watchdog */ atomic_io_modify(dev->rstout, WDT_RESET_OUT_EN, WDT_RESET_OUT_EN); return 0; } static int orion_wdt_stop(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); /* Disable reset on watchdog */ atomic_io_modify(dev->rstout, WDT_RESET_OUT_EN, 0); /* Disable watchdog timer */ atomic_io_modify(dev->reg + TIMER_CTRL, WDT_EN, 0); return 0; } static int orion_wdt_enabled(struct orion_watchdog *dev) { bool enabled, running; enabled = readl(dev->rstout) & WDT_RESET_OUT_EN; running = readl(dev->reg + TIMER_CTRL) & WDT_EN; return enabled && running; } static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev) { struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); return readl(dev->reg + WDT_VAL) / dev->clk_rate; } static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int timeout) { wdt_dev->timeout = timeout; return 0; } static const struct watchdog_info orion_wdt_info = { .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, .identity = "Orion Watchdog", }; static const struct watchdog_ops orion_wdt_ops = { .owner = THIS_MODULE, .start = orion_wdt_start, .stop = orion_wdt_stop, .ping = orion_wdt_ping, .set_timeout = orion_wdt_set_timeout, .get_timeleft = orion_wdt_get_timeleft, }; static irqreturn_t orion_wdt_irq(int irq, void *devid) { panic("Watchdog Timeout"); return IRQ_HANDLED; } /* * The original devicetree binding for this driver specified only * one memory resource, so in order to keep DT backwards compatibility * we try to fallback to a hardcoded register address, if the resource * is missing from the devicetree. */ static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev, phys_addr_t internal_regs) { struct resource *res; phys_addr_t rstout; res = platform_get_resource(pdev, IORESOURCE_MEM, 1); if (res) return devm_ioremap(&pdev->dev, res->start, resource_size(res)); /* This workaround works only for "orion-wdt", DT-enabled */ if (!of_device_is_compatible(pdev->dev.of_node, "marvell,orion-wdt")) return NULL; rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET; WARN(1, FW_BUG "falling back to harcoded RSTOUT reg 0x%x\n", rstout); return devm_ioremap(&pdev->dev, rstout, 0x4); } static int orion_wdt_probe(struct platform_device *pdev) { struct orion_watchdog *dev; unsigned int wdt_max_duration; /* (seconds) */ struct resource *res; int ret, irq; dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog), GFP_KERNEL); if (!dev) return -ENOMEM; dev->wdt.info = &orion_wdt_info; dev->wdt.ops = &orion_wdt_ops; dev->wdt.min_timeout = 1; dev->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(dev->clk)) { dev_err(&pdev->dev, "Orion Watchdog missing clock\n"); return PTR_ERR(dev->clk); } ret = clk_prepare_enable(dev->clk); if (ret) return ret; dev->clk_rate = clk_get_rate(dev->clk); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { ret = -ENODEV; goto disable_clk; } dev->reg = devm_ioremap(&pdev->dev, res->start, resource_size(res)); if (!dev->reg) { ret = -ENOMEM; goto disable_clk; } dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start & INTERNAL_REGS_MASK); if (!dev->rstout) { ret = -ENODEV; goto disable_clk; } wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate; dev->wdt.timeout = wdt_max_duration; dev->wdt.max_timeout = wdt_max_duration; watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev); platform_set_drvdata(pdev, &dev->wdt); watchdog_set_drvdata(&dev->wdt, dev); /* * Let's make sure the watchdog is fully stopped, unless it's * explicitly enabled. This may be the case if the module was * removed and re-insterted, or if the bootloader explicitly * set a running watchdog before booting the kernel. */ if (!orion_wdt_enabled(dev)) orion_wdt_stop(&dev->wdt); /* Request the IRQ only after the watchdog is disabled */ irq = platform_get_irq(pdev, 0); if (irq > 0) { /* * Not all supported platforms specify an interrupt for the * watchdog, so let's make it optional. */ ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0, pdev->name, dev); if (ret < 0) { dev_err(&pdev->dev, "failed to request IRQ\n"); goto disable_clk; } } watchdog_set_nowayout(&dev->wdt, nowayout); ret = watchdog_register_device(&dev->wdt); if (ret) goto disable_clk; pr_info("Initial timeout %d sec%s\n", dev->wdt.timeout, nowayout ? ", nowayout" : ""); return 0; disable_clk: clk_disable_unprepare(dev->clk); return ret; } static int orion_wdt_remove(struct platform_device *pdev) { struct watchdog_device *wdt_dev = platform_get_drvdata(pdev); struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); watchdog_unregister_device(wdt_dev); clk_disable_unprepare(dev->clk); return 0; } static void orion_wdt_shutdown(struct platform_device *pdev) { struct watchdog_device *wdt_dev = platform_get_drvdata(pdev); orion_wdt_stop(wdt_dev); } static const struct of_device_id orion_wdt_of_match_table[] = { { .compatible = "marvell,orion-wdt", }, {}, }; MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table); static struct platform_driver orion_wdt_driver = { .probe = orion_wdt_probe, .remove = orion_wdt_remove, .shutdown = orion_wdt_shutdown, .driver = { .owner = THIS_MODULE, .name = "orion_wdt", .of_match_table = orion_wdt_of_match_table, }, }; module_platform_driver(orion_wdt_driver); MODULE_AUTHOR("Sylver Bruneau "); MODULE_DESCRIPTION("Orion Processor Watchdog"); module_param(heartbeat, int, 0); MODULE_PARM_DESC(heartbeat, "Initial 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_ALIAS("platform:orion_wdt");