diff options
| -rw-r--r-- | drivers/watchdog/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/watchdog/imgpdc_wdt.c | 289 |
3 files changed, 301 insertions, 0 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 08f41add146..0a1396b70b9 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1235,6 +1235,17 @@ config BCM_KONA_WDT_DEBUG If in doubt, say 'N'. +config IMGPDC_WDT + tristate "Imagination Technologies PDC Watchdog Timer" + depends on HAS_IOMEM + depends on METAG || MIPS || COMPILE_TEST + help + Driver for Imagination Technologies PowerDown Controller + Watchdog Timer. + + To compile this driver as a loadable module, choose M here. + The module will be called imgpdc_wdt. + config LANTIQ_WDT tristate "Lantiq SoC watchdog" depends on LANTIQ diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index c569ec8f8a7..d4dfbb4fd01 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -142,6 +142,7 @@ obj-$(CONFIG_OCTEON_WDT) += octeon-wdt.o octeon-wdt-y := octeon-wdt-main.o octeon-wdt-nmi.o obj-$(CONFIG_LANTIQ_WDT) += lantiq_wdt.o obj-$(CONFIG_RALINK_WDT) += rt2880_wdt.o +obj-$(CONFIG_IMGPDC_WDT) += imgpdc_wdt.o # PARISC Architecture diff --git a/drivers/watchdog/imgpdc_wdt.c b/drivers/watchdog/imgpdc_wdt.c new file mode 100644 index 00000000000..c8def68d9e4 --- /dev/null +++ b/drivers/watchdog/imgpdc_wdt.c @@ -0,0 +1,289 @@ +/* + * Imagination Technologies PowerDown Controller Watchdog Timer. + * + * Copyright (c) 2014 Imagination Technologies Ltd. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * Based on drivers/watchdog/sunxi_wdt.c Copyright (c) 2013 Carlo Caione + * 2012 Henrik Nordstrom + */ + +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/log2.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/watchdog.h> + +/* registers */ +#define PDC_WDT_SOFT_RESET 0x00 +#define PDC_WDT_CONFIG 0x04 + #define PDC_WDT_CONFIG_ENABLE BIT(31) + #define PDC_WDT_CONFIG_DELAY_MASK 0x1f + +#define PDC_WDT_TICKLE1 0x08 +#define PDC_WDT_TICKLE1_MAGIC 0xabcd1234 +#define PDC_WDT_TICKLE2 0x0c +#define PDC_WDT_TICKLE2_MAGIC 0x4321dcba + +#define PDC_WDT_TICKLE_STATUS_MASK 0x7 +#define PDC_WDT_TICKLE_STATUS_SHIFT 0 +#define PDC_WDT_TICKLE_STATUS_HRESET 0x0 /* Hard reset */ +#define PDC_WDT_TICKLE_STATUS_TIMEOUT 0x1 /* Timeout */ +#define PDC_WDT_TICKLE_STATUS_TICKLE 0x2 /* Tickled incorrectly */ +#define PDC_WDT_TICKLE_STATUS_SRESET 0x3 /* Soft reset */ +#define PDC_WDT_TICKLE_STATUS_USER 0x4 /* User reset */ + +/* Timeout values are in seconds */ +#define PDC_WDT_MIN_TIMEOUT 1 +#define PDC_WDT_DEF_TIMEOUT 64 + +static int heartbeat; +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. " + "(default = " __MODULE_STRING(PDC_WDT_DEF_TIMEOUT) ")"); + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +struct pdc_wdt_dev { + struct watchdog_device wdt_dev; + struct clk *wdt_clk; + struct clk *sys_clk; + void __iomem *base; +}; + +static int pdc_wdt_keepalive(struct watchdog_device *wdt_dev) +{ + struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); + + writel(PDC_WDT_TICKLE1_MAGIC, wdt->base + PDC_WDT_TICKLE1); + writel(PDC_WDT_TICKLE2_MAGIC, wdt->base + PDC_WDT_TICKLE2); + + return 0; +} + +static int pdc_wdt_stop(struct watchdog_device *wdt_dev) +{ + unsigned int val; + struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); + + val = readl(wdt->base + PDC_WDT_CONFIG); + val &= ~PDC_WDT_CONFIG_ENABLE; + writel(val, wdt->base + PDC_WDT_CONFIG); + + /* Must tickle to finish the stop */ + pdc_wdt_keepalive(wdt_dev); + + return 0; +} + +static int pdc_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int new_timeout) +{ + unsigned int val; + struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); + unsigned long clk_rate = clk_get_rate(wdt->wdt_clk); + + wdt->wdt_dev.timeout = new_timeout; + + val = readl(wdt->base + PDC_WDT_CONFIG) & ~PDC_WDT_CONFIG_DELAY_MASK; + val |= order_base_2(new_timeout * clk_rate) - 1; + writel(val, wdt->base + PDC_WDT_CONFIG); + + return 0; +} + +/* Start the watchdog timer (delay should already be set) */ +static int pdc_wdt_start(struct watchdog_device *wdt_dev) +{ + unsigned int val; + struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev); + + val = readl(wdt->base + PDC_WDT_CONFIG); + val |= PDC_WDT_CONFIG_ENABLE; + writel(val, wdt->base + PDC_WDT_CONFIG); + + return 0; +} + +static struct watchdog_info pdc_wdt_info = { + .identity = "IMG PDC Watchdog", + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops pdc_wdt_ops = { + .owner = THIS_MODULE, + .start = pdc_wdt_start, + .stop = pdc_wdt_stop, + .ping = pdc_wdt_keepalive, + .set_timeout = pdc_wdt_set_timeout, +}; + +static int pdc_wdt_probe(struct platform_device *pdev) +{ + int ret, val; + unsigned long clk_rate; + struct resource *res; + struct pdc_wdt_dev *pdc_wdt; + + pdc_wdt = devm_kzalloc(&pdev->dev, sizeof(*pdc_wdt), GFP_KERNEL); + if (!pdc_wdt) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + pdc_wdt->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(pdc_wdt->base)) + return PTR_ERR(pdc_wdt->base); + + pdc_wdt->sys_clk = devm_clk_get(&pdev->dev, "sys"); + if (IS_ERR(pdc_wdt->sys_clk)) { + dev_err(&pdev->dev, "failed to get the sys clock\n"); + return PTR_ERR(pdc_wdt->sys_clk); + } + + pdc_wdt->wdt_clk = devm_clk_get(&pdev->dev, "wdt"); + if (IS_ERR(pdc_wdt->wdt_clk)) { + dev_err(&pdev->dev, "failed to get the wdt clock\n"); + return PTR_ERR(pdc_wdt->wdt_clk); + } + + ret = clk_prepare_enable(pdc_wdt->sys_clk); + if (ret) { + dev_err(&pdev->dev, "could not prepare or enable sys clock\n"); + return ret; + } + + ret = clk_prepare_enable(pdc_wdt->wdt_clk); + if (ret) { + dev_err(&pdev->dev, "could not prepare or enable wdt clock\n"); + goto disable_sys_clk; + } + + /* We use the clock rate to calculate the max timeout */ + clk_rate = clk_get_rate(pdc_wdt->wdt_clk); + if (clk_rate == 0) { + dev_err(&pdev->dev, "failed to get clock rate\n"); + ret = -EINVAL; + goto disable_wdt_clk; + } + + if (order_base_2(clk_rate) > PDC_WDT_CONFIG_DELAY_MASK + 1) { + dev_err(&pdev->dev, "invalid clock rate\n"); + ret = -EINVAL; + goto disable_wdt_clk; + } + + if (order_base_2(clk_rate) == 0) + pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT + 1; + else + pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT; + + pdc_wdt->wdt_dev.info = &pdc_wdt_info; + pdc_wdt->wdt_dev.ops = &pdc_wdt_ops; + pdc_wdt->wdt_dev.max_timeout = 1 << PDC_WDT_CONFIG_DELAY_MASK; + pdc_wdt->wdt_dev.parent = &pdev->dev; + + ret = watchdog_init_timeout(&pdc_wdt->wdt_dev, heartbeat, &pdev->dev); + if (ret < 0) { + pdc_wdt->wdt_dev.timeout = pdc_wdt->wdt_dev.max_timeout; + dev_warn(&pdev->dev, + "Initial timeout out of range! setting max timeout\n"); + } + + pdc_wdt_stop(&pdc_wdt->wdt_dev); + + /* Find what caused the last reset */ + val = readl(pdc_wdt->base + PDC_WDT_TICKLE1); + val = (val & PDC_WDT_TICKLE_STATUS_MASK) >> PDC_WDT_TICKLE_STATUS_SHIFT; + switch (val) { + case PDC_WDT_TICKLE_STATUS_TICKLE: + case PDC_WDT_TICKLE_STATUS_TIMEOUT: + pdc_wdt->wdt_dev.bootstatus |= WDIOF_CARDRESET; + dev_info(&pdev->dev, + "watchdog module last reset due to timeout\n"); + break; + case PDC_WDT_TICKLE_STATUS_HRESET: + dev_info(&pdev->dev, + "watchdog module last reset due to hard reset\n"); + break; + case PDC_WDT_TICKLE_STATUS_SRESET: + dev_info(&pdev->dev, + "watchdog module last reset due to soft reset\n"); + break; + case PDC_WDT_TICKLE_STATUS_USER: + dev_info(&pdev->dev, + "watchdog module last reset due to user reset\n"); + break; + default: + dev_info(&pdev->dev, + "contains an illegal status code (%08x)\n", val); + break; + } + + watchdog_set_nowayout(&pdc_wdt->wdt_dev, nowayout); + + platform_set_drvdata(pdev, pdc_wdt); + watchdog_set_drvdata(&pdc_wdt->wdt_dev, pdc_wdt); + + ret = watchdog_register_device(&pdc_wdt->wdt_dev); + if (ret) + goto disable_wdt_clk; + + return 0; + +disable_wdt_clk: + clk_disable_unprepare(pdc_wdt->wdt_clk); +disable_sys_clk: + clk_disable_unprepare(pdc_wdt->sys_clk); + return ret; +} + +static void pdc_wdt_shutdown(struct platform_device *pdev) +{ + struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev); + + pdc_wdt_stop(&pdc_wdt->wdt_dev); +} + +static int pdc_wdt_remove(struct platform_device *pdev) +{ + struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev); + + pdc_wdt_stop(&pdc_wdt->wdt_dev); + watchdog_unregister_device(&pdc_wdt->wdt_dev); + clk_disable_unprepare(pdc_wdt->wdt_clk); + clk_disable_unprepare(pdc_wdt->sys_clk); + + return 0; +} + +static const struct of_device_id pdc_wdt_match[] = { + { .compatible = "img,pdc-wdt" }, + {} +}; +MODULE_DEVICE_TABLE(of, pdc_wdt_match); + +static struct platform_driver pdc_wdt_driver = { + .driver = { + .name = "imgpdc-wdt", + .of_match_table = pdc_wdt_match, + }, + .probe = pdc_wdt_probe, + .remove = pdc_wdt_remove, + .shutdown = pdc_wdt_shutdown, +}; +module_platform_driver(pdc_wdt_driver); + +MODULE_AUTHOR("Jude Abraham <Jude.Abraham@imgtec.com>"); +MODULE_AUTHOR("Naidu Tellapati <Naidu.Tellapati@imgtec.com>"); +MODULE_DESCRIPTION("Imagination Technologies PDC Watchdog Timer Driver"); +MODULE_LICENSE("GPL v2"); |