diff options
Diffstat (limited to 'drivers/watchdog/orion_wdt.c')
| -rw-r--r-- | drivers/watchdog/orion_wdt.c | 654 |
1 files changed, 654 insertions, 0 deletions
diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c new file mode 100644 index 000000000..ef0c628d5 --- /dev/null +++ b/drivers/watchdog/orion_wdt.c @@ -0,0 +1,654 @@ +/* + * drivers/watchdog/orion_wdt.c + * + * Watchdog driver for Orion/Kirkwood processors + * + * Author: Sylver Bruneau <sylver.bruneau@googlemail.com> + * + * 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 <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/of_device.h> + +/* 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 TIMER_A370_STATUS 0x04 + +#define WDT_MAX_CYCLE_COUNT 0xffffffff + +#define WDT_A370_RATIO_MASK(v) ((v) << 16) +#define WDT_A370_RATIO_SHIFT 5 +#define WDT_A370_RATIO (1 << WDT_A370_RATIO_SHIFT) + +#define WDT_AXP_FIXED_ENABLE_BIT BIT(10) +#define WDT_A370_EXPIRED BIT(31) + +static bool nowayout = WATCHDOG_NOWAYOUT; +static int heartbeat = -1; /* module parameter (seconds) */ + +struct orion_watchdog; + +struct orion_watchdog_data { + int wdt_counter_offset; + int wdt_enable_bit; + int rstout_enable_bit; + int rstout_mask_bit; + int (*clock_init)(struct platform_device *, + struct orion_watchdog *); + int (*enabled)(struct orion_watchdog *); + int (*start)(struct watchdog_device *); + int (*stop)(struct watchdog_device *); +}; + +struct orion_watchdog { + struct watchdog_device wdt; + void __iomem *reg; + void __iomem *rstout; + void __iomem *rstout_mask; + unsigned long clk_rate; + struct clk *clk; + const struct orion_watchdog_data *data; +}; + +static int orion_wdt_clock_init(struct platform_device *pdev, + struct orion_watchdog *dev) +{ + int ret; + + dev->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(dev->clk)) + return PTR_ERR(dev->clk); + ret = clk_prepare_enable(dev->clk); + if (ret) { + clk_put(dev->clk); + return ret; + } + + dev->clk_rate = clk_get_rate(dev->clk); + return 0; +} + +static int armada370_wdt_clock_init(struct platform_device *pdev, + struct orion_watchdog *dev) +{ + int ret; + + dev->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(dev->clk)) + return PTR_ERR(dev->clk); + ret = clk_prepare_enable(dev->clk); + if (ret) { + clk_put(dev->clk); + return ret; + } + + /* Setup watchdog input clock */ + atomic_io_modify(dev->reg + TIMER_CTRL, + WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT), + WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT)); + + dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO; + return 0; +} + +static int armada375_wdt_clock_init(struct platform_device *pdev, + struct orion_watchdog *dev) +{ + int ret; + + dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed"); + if (!IS_ERR(dev->clk)) { + ret = clk_prepare_enable(dev->clk); + if (ret) { + clk_put(dev->clk); + return ret; + } + + atomic_io_modify(dev->reg + TIMER_CTRL, + WDT_AXP_FIXED_ENABLE_BIT, + WDT_AXP_FIXED_ENABLE_BIT); + dev->clk_rate = clk_get_rate(dev->clk); + + return 0; + } + + /* Mandatory fallback for proper devicetree backward compatibility */ + dev->clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(dev->clk)) + return PTR_ERR(dev->clk); + + ret = clk_prepare_enable(dev->clk); + if (ret) { + clk_put(dev->clk); + return ret; + } + + atomic_io_modify(dev->reg + TIMER_CTRL, + WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT), + WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT)); + dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO; + + return 0; +} + +static int armadaxp_wdt_clock_init(struct platform_device *pdev, + struct orion_watchdog *dev) +{ + int ret; + + dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed"); + if (IS_ERR(dev->clk)) + return PTR_ERR(dev->clk); + ret = clk_prepare_enable(dev->clk); + if (ret) { + clk_put(dev->clk); + return ret; + } + + /* Enable the fixed watchdog clock input */ + atomic_io_modify(dev->reg + TIMER_CTRL, + WDT_AXP_FIXED_ENABLE_BIT, + WDT_AXP_FIXED_ENABLE_BIT); + + dev->clk_rate = clk_get_rate(dev->clk); + return 0; +} + +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 + dev->data->wdt_counter_offset); + return 0; +} + +static int armada375_start(struct watchdog_device *wdt_dev) +{ + struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + u32 reg; + + /* Set watchdog duration */ + writel(dev->clk_rate * wdt_dev->timeout, + dev->reg + dev->data->wdt_counter_offset); + + /* Clear the watchdog expiration bit */ + atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0); + + /* Enable watchdog timer */ + atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, + dev->data->wdt_enable_bit); + + /* Enable reset on watchdog */ + reg = readl(dev->rstout); + reg |= dev->data->rstout_enable_bit; + writel(reg, dev->rstout); + + atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, 0); + return 0; +} + +static int armada370_start(struct watchdog_device *wdt_dev) +{ + struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + u32 reg; + + /* Set watchdog duration */ + writel(dev->clk_rate * wdt_dev->timeout, + dev->reg + dev->data->wdt_counter_offset); + + /* Clear the watchdog expiration bit */ + atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0); + + /* Enable watchdog timer */ + atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, + dev->data->wdt_enable_bit); + + /* Enable reset on watchdog */ + reg = readl(dev->rstout); + reg |= dev->data->rstout_enable_bit; + writel(reg, dev->rstout); + return 0; +} + +static int orion_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 + dev->data->wdt_counter_offset); + + /* Enable watchdog timer */ + atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, + dev->data->wdt_enable_bit); + + /* Enable reset on watchdog */ + atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, + dev->data->rstout_enable_bit); + + return 0; +} + +static int orion_wdt_start(struct watchdog_device *wdt_dev) +{ + struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + + /* There are some per-SoC quirks to handle */ + return dev->data->start(wdt_dev); +} + +static int orion_stop(struct watchdog_device *wdt_dev) +{ + struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + + /* Disable reset on watchdog */ + atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0); + + /* Disable watchdog timer */ + atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0); + + return 0; +} + +static int armada375_stop(struct watchdog_device *wdt_dev) +{ + struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + u32 reg; + + /* Disable reset on watchdog */ + atomic_io_modify(dev->rstout_mask, dev->data->rstout_mask_bit, + dev->data->rstout_mask_bit); + reg = readl(dev->rstout); + reg &= ~dev->data->rstout_enable_bit; + writel(reg, dev->rstout); + + /* Disable watchdog timer */ + atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0); + + return 0; +} + +static int armada370_stop(struct watchdog_device *wdt_dev) +{ + struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + u32 reg; + + /* Disable reset on watchdog */ + reg = readl(dev->rstout); + reg &= ~dev->data->rstout_enable_bit; + writel(reg, dev->rstout); + + /* Disable watchdog timer */ + atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0); + + return 0; +} + +static int orion_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + + return dev->data->stop(wdt_dev); +} + +static int orion_enabled(struct orion_watchdog *dev) +{ + bool enabled, running; + + enabled = readl(dev->rstout) & dev->data->rstout_enable_bit; + running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit; + + return enabled && running; +} + +static int armada375_enabled(struct orion_watchdog *dev) +{ + bool masked, enabled, running; + + masked = readl(dev->rstout_mask) & dev->data->rstout_mask_bit; + enabled = readl(dev->rstout) & dev->data->rstout_enable_bit; + running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit; + + return !masked && enabled && running; +} + +static int orion_wdt_enabled(struct watchdog_device *wdt_dev) +{ + struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev); + + return dev->data->enabled(dev); +} + +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 + dev->data->wdt_counter_offset) / 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)); + + rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET; + + WARN(1, FW_BUG "falling back to harcoded RSTOUT reg %pa\n", &rstout); + return devm_ioremap(&pdev->dev, rstout, 0x4); +} + +static const struct orion_watchdog_data orion_data = { + .rstout_enable_bit = BIT(1), + .wdt_enable_bit = BIT(4), + .wdt_counter_offset = 0x24, + .clock_init = orion_wdt_clock_init, + .enabled = orion_enabled, + .start = orion_start, + .stop = orion_stop, +}; + +static const struct orion_watchdog_data armada370_data = { + .rstout_enable_bit = BIT(8), + .wdt_enable_bit = BIT(8), + .wdt_counter_offset = 0x34, + .clock_init = armada370_wdt_clock_init, + .enabled = orion_enabled, + .start = armada370_start, + .stop = armada370_stop, +}; + +static const struct orion_watchdog_data armadaxp_data = { + .rstout_enable_bit = BIT(8), + .wdt_enable_bit = BIT(8), + .wdt_counter_offset = 0x34, + .clock_init = armadaxp_wdt_clock_init, + .enabled = orion_enabled, + .start = armada370_start, + .stop = armada370_stop, +}; + +static const struct orion_watchdog_data armada375_data = { + .rstout_enable_bit = BIT(8), + .rstout_mask_bit = BIT(10), + .wdt_enable_bit = BIT(8), + .wdt_counter_offset = 0x34, + .clock_init = armada375_wdt_clock_init, + .enabled = armada375_enabled, + .start = armada375_start, + .stop = armada375_stop, +}; + +static const struct orion_watchdog_data armada380_data = { + .rstout_enable_bit = BIT(8), + .rstout_mask_bit = BIT(10), + .wdt_enable_bit = BIT(8), + .wdt_counter_offset = 0x34, + .clock_init = armadaxp_wdt_clock_init, + .enabled = armada375_enabled, + .start = armada375_start, + .stop = armada375_stop, +}; + +static const struct of_device_id orion_wdt_of_match_table[] = { + { + .compatible = "marvell,orion-wdt", + .data = &orion_data, + }, + { + .compatible = "marvell,armada-370-wdt", + .data = &armada370_data, + }, + { + .compatible = "marvell,armada-xp-wdt", + .data = &armadaxp_data, + }, + { + .compatible = "marvell,armada-375-wdt", + .data = &armada375_data, + }, + { + .compatible = "marvell,armada-380-wdt", + .data = &armada380_data, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table); + +static int orion_wdt_get_regs(struct platform_device *pdev, + struct orion_watchdog *dev) +{ + struct device_node *node = pdev->dev.of_node; + struct resource *res; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + dev->reg = devm_ioremap(&pdev->dev, res->start, + resource_size(res)); + if (!dev->reg) + return -ENOMEM; + + /* Each supported compatible has some RSTOUT register quirk */ + if (of_device_is_compatible(node, "marvell,orion-wdt")) { + + dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start & + INTERNAL_REGS_MASK); + if (!dev->rstout) + return -ENODEV; + + } else if (of_device_is_compatible(node, "marvell,armada-370-wdt") || + of_device_is_compatible(node, "marvell,armada-xp-wdt")) { + + /* Dedicated RSTOUT register, can be requested. */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + dev->rstout = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dev->rstout)) + return PTR_ERR(dev->rstout); + + } else if (of_device_is_compatible(node, "marvell,armada-375-wdt") || + of_device_is_compatible(node, "marvell,armada-380-wdt")) { + + /* Dedicated RSTOUT register, can be requested. */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + dev->rstout = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dev->rstout)) + return PTR_ERR(dev->rstout); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 2); + if (!res) + return -ENODEV; + dev->rstout_mask = devm_ioremap(&pdev->dev, res->start, + resource_size(res)); + if (!dev->rstout_mask) + return -ENOMEM; + + } else { + return -ENODEV; + } + + return 0; +} + +static int orion_wdt_probe(struct platform_device *pdev) +{ + struct orion_watchdog *dev; + const struct of_device_id *match; + unsigned int wdt_max_duration; /* (seconds) */ + int ret, irq; + + dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog), + GFP_KERNEL); + if (!dev) + return -ENOMEM; + + match = of_match_device(orion_wdt_of_match_table, &pdev->dev); + if (!match) + /* Default legacy match */ + match = &orion_wdt_of_match_table[0]; + + dev->wdt.info = &orion_wdt_info; + dev->wdt.ops = &orion_wdt_ops; + dev->wdt.min_timeout = 1; + dev->data = match->data; + + ret = orion_wdt_get_regs(pdev, dev); + if (ret) + return ret; + + ret = dev->data->clock_init(pdev, dev); + if (ret) { + dev_err(&pdev->dev, "cannot initialize clock\n"); + return ret; + } + + 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->wdt)) + 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); + clk_put(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); + clk_put(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 struct platform_driver orion_wdt_driver = { + .probe = orion_wdt_probe, + .remove = orion_wdt_remove, + .shutdown = orion_wdt_shutdown, + .driver = { + .name = "orion_wdt", + .of_match_table = orion_wdt_of_match_table, + }, +}; + +module_platform_driver(orion_wdt_driver); + +MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>"); +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"); |