From: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@xxxxxxxxx> Intel Keembay Soc requires watchdog timer support. Add watchdog driver to enable this. Signed-off-by: Vijayakannan Ayyathurai <vijayakannan.ayyathurai@xxxxxxxxx> Acked-by: Mark Gross <mgross@xxxxxxxxxxxxxxx> Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- drivers/watchdog/Kconfig | 13 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/keembay_wdt.c | 284 +++++++++++++++++++++++++++++++++ 3 files changed, 298 insertions(+) create mode 100644 drivers/watchdog/keembay_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index fd7968635e6d..f412cf2d0f1a 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -2163,4 +2163,17 @@ config USBPCWATCHDOG Most people will say N. +config KEEMBAY_WATCHDOG + tristate "Intel Keem Bay SoC non-secure watchdog" + depends on ARCH_KEEMBAY || (ARM64 && COMPILE_TEST) + select WATCHDOG_CORE + help + This option enable support for an In-secure watchdog timer driver for + Intel Keem Bay SoC. This WDT has a 32 bit timer and decrements in every + count unit. An interrupt will be triggered, when the count crosses + the thershold configured in the register. + + To compile this driver as a module, choose M here: the + module will be called keembay_wdt. + endif # WATCHDOG diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 071a2e50be98..f6f9f434f407 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -146,6 +146,7 @@ obj-$(CONFIG_INTEL_MEI_WDT) += mei_wdt.o obj-$(CONFIG_NI903X_WDT) += ni903x_wdt.o obj-$(CONFIG_NIC7018_WDT) += nic7018_wdt.o obj-$(CONFIG_MLX_WDT) += mlx_wdt.o +obj-$(CONFIG_KEEMBAY_WATCHDOG) += keembay_wdt.o # M68K Architecture obj-$(CONFIG_M54xx_WATCHDOG) += m54xx_wdt.o diff --git a/drivers/watchdog/keembay_wdt.c b/drivers/watchdog/keembay_wdt.c new file mode 100644 index 000000000000..1e1a1447c729 --- /dev/null +++ b/drivers/watchdog/keembay_wdt.c @@ -0,0 +1,284 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Watchdog driver for Intel Keem Bay non-secure watchdog. + * + * Copyright (C) 2020 Intel Corporation + */ + +#include <linux/arm-smccc.h> +#include <linux/bits.h> +#include <linux/clk.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/limits.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/watchdog.h> + +/* Non-secure watchdog register offsets */ +#define TIM_WATCHDOG 0x0 +#define TIM_WATCHDOG_INT_THRES 0x4 +#define TIM_WDOG_EN 0x8 +#define TIM_SAFE 0xc + +#define WDT_ISR_MASK GENMASK(9, 8) +#define WDT_ISR_CLEAR 0x8200ff18 +#define WDT_UNLOCK 0xf1d0dead +#define WDT_LOAD_MAX U32_MAX +#define WDT_LOAD_MIN 1 +#define WDT_TIMEOUT 5 + +static unsigned int timeout = WDT_TIMEOUT; +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout period in seconds (default = " + __MODULE_STRING(WDT_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 keembay_wdt { + struct watchdog_device wdd; + struct clk *clk; + unsigned int rate; + int to_irq; + int th_irq; + void __iomem *base; +}; + +static inline u32 keembay_wdt_readl(struct keembay_wdt *wdt, u32 offset) +{ + return readl(wdt->base + offset); +} + +static inline void keembay_wdt_writel(struct keembay_wdt *wdt, + u32 offset, u32 val) +{ + writel(WDT_UNLOCK, wdt->base + TIM_SAFE); + writel(val, wdt->base + offset); +} + +static void keembay_wdt_set_timeout_reg(struct watchdog_device *wdog, bool ping) +{ + struct keembay_wdt *wdt = watchdog_get_drvdata(wdog); + u32 th_val = 0; + + if (!ping && wdog->pretimeout) { + th_val = wdog->timeout - wdog->pretimeout; + keembay_wdt_writel(wdt, TIM_WATCHDOG_INT_THRES, th_val * wdt->rate); + } + + keembay_wdt_writel(wdt, TIM_WATCHDOG, wdog->timeout * wdt->rate); +} + +static int keembay_wdt_start(struct watchdog_device *wdog) +{ + struct keembay_wdt *wdt = watchdog_get_drvdata(wdog); + + keembay_wdt_set_timeout_reg(wdog, false); + keembay_wdt_writel(wdt, TIM_WDOG_EN, 1); + + return 0; +} + +static int keembay_wdt_stop(struct watchdog_device *wdog) +{ + struct keembay_wdt *wdt = watchdog_get_drvdata(wdog); + + keembay_wdt_writel(wdt, TIM_WDOG_EN, 0); + + return 0; +} + +static int keembay_wdt_ping(struct watchdog_device *wdog) +{ + keembay_wdt_set_timeout_reg(wdog, true); + + return 0; +} + +static int keembay_wdt_set_timeout(struct watchdog_device *wdog, u32 t) +{ + wdog->timeout = t; + keembay_wdt_set_timeout_reg(wdog, false); + + return 0; +} + +static int keembay_wdt_set_pretimeout(struct watchdog_device *wdog, u32 t) +{ + wdog->pretimeout = t; + keembay_wdt_set_timeout_reg(wdog, false); + + return 0; +} + +static unsigned int keembay_wdt_get_timeleft(struct watchdog_device *wdog) +{ + struct keembay_wdt *wdt = watchdog_get_drvdata(wdog); + + return keembay_wdt_readl(wdt, TIM_WATCHDOG) / wdt->rate; +} + +/* + * SMC call is used to clear the interrupt bits, because the TIM_GEN_CONFIG + * register is in the secure bank. + */ +static irqreturn_t keembay_wdt_to_isr(int irq, void *dev_id) +{ + struct keembay_wdt *wdt = dev_id; + struct arm_smccc_res res; + + keembay_wdt_writel(wdt, TIM_WATCHDOG, 1); + arm_smccc_smc(WDT_ISR_CLEAR, WDT_ISR_MASK, 0, 0, 0, 0, 0, 0, &res); + dev_crit(wdt->wdd.parent, "Intel Keem Bay non-sec wdt timeout.\n"); + emergency_restart(); + + return IRQ_HANDLED; +} + +static irqreturn_t keembay_wdt_th_isr(int irq, void *dev_id) +{ + struct keembay_wdt *wdt = dev_id; + struct arm_smccc_res res; + u32 th_val = 0; + + if (wdt->wdd.pretimeout) + th_val = wdt->wdd.timeout - wdt->wdd.pretimeout; + + keembay_wdt_writel(wdt, TIM_WATCHDOG, th_val * wdt->rate + 1); + arm_smccc_smc(WDT_ISR_CLEAR, WDT_ISR_MASK, 0, 0, 0, 0, 0, 0, &res); + dev_crit(wdt->wdd.parent, "Intel Keem Bay non-sec wdt pre-timeout.\n"); + watchdog_notify_pretimeout(&wdt->wdd); + + return IRQ_HANDLED; +} + +static const struct watchdog_info keembay_wdt_info = { + .identity = "Intel Keem Bay Watchdog Timer", + .options = WDIOF_SETTIMEOUT | + WDIOF_PRETIMEOUT | + WDIOF_MAGICCLOSE | + WDIOF_KEEPALIVEPING, +}; + +static const struct watchdog_ops keembay_wdt_ops = { + .owner = THIS_MODULE, + .start = keembay_wdt_start, + .stop = keembay_wdt_stop, + .ping = keembay_wdt_ping, + .set_timeout = keembay_wdt_set_timeout, + .set_pretimeout = keembay_wdt_set_pretimeout, + .get_timeleft = keembay_wdt_get_timeleft, +}; + +static int keembay_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct keembay_wdt *wdt; + int ret; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(wdt->base)) + return PTR_ERR(wdt->base); + + /* we do not need to enable the clock as it is enabled by default */ + wdt->clk = devm_clk_get(dev, NULL); + if (IS_ERR(wdt->clk)) + return dev_err_probe(dev, PTR_ERR(wdt->clk), "Failed to get clock\n"); + + wdt->rate = clk_get_rate(wdt->clk); + if (!wdt->rate) + return dev_err_probe(dev, -EINVAL, "Failed to get clock rate\n"); + + wdt->th_irq = platform_get_irq_byname(pdev, "threshold"); + if (wdt->th_irq < 0) + return dev_err_probe(dev, wdt->th_irq, "Failed to get IRQ for threshold\n"); + + ret = devm_request_irq(dev, wdt->th_irq, keembay_wdt_th_isr, 0, + "keembay-wdt", wdt); + if (ret) + return dev_err_probe(dev, ret, "Failed to request IRQ for threshold\n"); + + wdt->to_irq = platform_get_irq_byname(pdev, "timeout"); + if (wdt->to_irq < 0) + return dev_err_probe(dev, wdt->to_irq, "Failed to get IRQ for timeout\n"); + + ret = devm_request_irq(dev, wdt->to_irq, keembay_wdt_to_isr, 0, + "keembay-wdt", wdt); + if (ret) + return dev_err_probe(dev, ret, "Failed to request IRQ for timeout\n"); + + wdt->wdd.parent = dev; + wdt->wdd.info = &keembay_wdt_info; + wdt->wdd.ops = &keembay_wdt_ops; + wdt->wdd.min_timeout = WDT_LOAD_MIN; + wdt->wdd.max_timeout = WDT_LOAD_MAX / wdt->rate; + wdt->wdd.timeout = WDT_TIMEOUT; + + watchdog_set_drvdata(&wdt->wdd, wdt); + watchdog_set_nowayout(&wdt->wdd, nowayout); + watchdog_init_timeout(&wdt->wdd, timeout, dev); + keembay_wdt_set_timeout(&wdt->wdd, wdt->wdd.timeout); + + ret = devm_watchdog_register_device(dev, &wdt->wdd); + if (ret) + return dev_err_probe(dev, ret, "Failed to register watchdog device.\n"); + + platform_set_drvdata(pdev, wdt); + dev_info(dev, "Initial timeout %d sec%s.\n", + wdt->wdd.timeout, nowayout ? ", nowayout" : ""); + + return 0; +} + +static int __maybe_unused keembay_wdt_suspend(struct device *dev) +{ + struct keembay_wdt *wdt = dev_get_drvdata(dev); + + if (watchdog_active(&wdt->wdd)) + return keembay_wdt_stop(&wdt->wdd); + + return 0; +} + +static int __maybe_unused keembay_wdt_resume(struct device *dev) +{ + struct keembay_wdt *wdt = dev_get_drvdata(dev); + + if (watchdog_active(&wdt->wdd)) + return keembay_wdt_start(&wdt->wdd); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(keembay_wdt_pm_ops, keembay_wdt_suspend, + keembay_wdt_resume); + +static const struct of_device_id keembay_wdt_match[] = { + { .compatible = "intel,keembay-wdt" }, + { } +}; +MODULE_DEVICE_TABLE(of, keembay_wdt_match); + +static struct platform_driver keembay_wdt_driver = { + .probe = keembay_wdt_probe, + .driver = { + .name = "keembay_wdt", + .of_match_table = keembay_wdt_match, + .pm = &keembay_wdt_pm_ops, + }, +}; + +module_platform_driver(keembay_wdt_driver); + +MODULE_DESCRIPTION("Intel Keem Bay SoC watchdog driver"); +MODULE_AUTHOR("Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@xxxxxxxxx"); +MODULE_LICENSE("GPL v2"); -- 2.17.1