On Tue, Sep 12, 2017 at 07:40:09PM +0800, Eric Long wrote: > This patch adds the watchdog driver for Spreadtrum SC9860 platform. > > Signed-off-by: Eric Long <eric.long@xxxxxxxxxxxxxx> > --- > Changes since v1: > - Use pretimeout instead of own implementation. > - Fix timeout loop when loading timeout values. > - use the infrastructure to read and set "timeout-sec" property. > - Add conditions when start or stop watchdog. > - Change the position of enabling watchdog. > - Other optimization. > --- > drivers/watchdog/Kconfig | 8 + > drivers/watchdog/Makefile | 1 + > drivers/watchdog/sprd_wdt.c | 384 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 393 insertions(+) > create mode 100644 drivers/watchdog/sprd_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index c722cbf..ea07718 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -787,6 +787,14 @@ config UNIPHIER_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called uniphier_wdt. > > +config SPRD_WATCHDOG > + tristate "Spreadtrum watchdog support" > + depends on ARCH_SPRD > + select WATCHDOG_CORE > + help > + Say Y here to include support watchdog timer embedded > + into the Spreadtrum system. > + > # AVR32 Architecture > > config AT32AP700X_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 56adf9f..187cca2 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -87,6 +87,7 @@ obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o > obj-$(CONFIG_ZX2967_WATCHDOG) += zx2967_wdt.o > obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o > obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o > +obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o > > # AVR32 Architecture > obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o > diff --git a/drivers/watchdog/sprd_wdt.c b/drivers/watchdog/sprd_wdt.c > new file mode 100644 > index 0000000..dedbca6fd > --- /dev/null > +++ b/drivers/watchdog/sprd_wdt.c > @@ -0,0 +1,384 @@ > +/* > + * Spreadtrum watchdog driver > + * Copyright (C) 2017 Spreadtrum - http://www.spreadtrum.com > + * > + * 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. > + * > + * 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. > + */ > + > +#include <linux/clk.h> > +#include <linux/err.h> > +#include <linux/interrupt.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_address.h> > +#include <linux/platform_device.h> > +#include <linux/watchdog.h> > + > +#define WDT_LOAD_LOW 0x0 > +#define WDT_LOAD_HIGH 0x4 > +#define WDT_CTRL 0x8 > +#define WDT_INT_CLR 0xc > +#define WDT_INT_RAW 0x10 > +#define WDT_INT_MSK 0x14 > +#define WDT_CNT_LOW 0x18 > +#define WDT_CNT_HIGH 0x1c > +#define WDT_LOCK 0x20 > +#define WDT_IRQ_LOAD_LOW 0x2c > +#define WDT_IRQ_LOAD_HIGH 0x30 > + > +/* WDT_CTRL */ > +#define WDT_INT_EN_BIT BIT(0) > +#define WDT_CNT_EN_BIT BIT(1) > +#define WDT_NEW_VER_EN BIT(2) > +#define WDT_RST_EN_BIT BIT(3) > + > +/* WDT_INT_CLR */ > +#define WDT_INT_CLEAR_BIT BIT(0) > +#define WDT_RST_CLEAR_BIT BIT(3) > + Requires include of bitops.h. > +/* WDT_INT_RAW */ > +#define WDT_INT_RAW_BIT BIT(0) > +#define WDT_RST_RAW_BIT BIT(3) > +#define WDT_LD_BUSY_BIT BIT(4) > + > +#define WDT_CLK 32768 Would it make sense to use clk_get_rate() instead ? > +#define WDT_UNLOCK_KEY 0xe551 > +#define WDT_DEFAULT_PRETMROUT 3 > + > +#define WDT_CNT_VALUE_SIZE 16 > +#define WDT_CNT_VALUE_MASK GENMASK(15, 0) > +#define WDT_LOAD_TIMEOUT_NUM 10000 > + > +struct sprd_wdt { > + void __iomem *base; > + struct watchdog_device wdd; > + struct clk *enable; > + struct clk *rtc_enable; > + unsigned int irq; > +}; > + > +static inline struct sprd_wdt *to_sprd_wdt(struct watchdog_device *wdd) > +{ > + return container_of(wdd, struct sprd_wdt, wdd); > +} > + > +static inline void sprd_wdt_lock(void __iomem *addr) > +{ > + writel_relaxed(0x0, addr + WDT_LOCK); > +} > + > +static inline void sprd_wdt_unlock(void __iomem *addr) > +{ > + writel_relaxed(WDT_UNLOCK_KEY, addr + WDT_LOCK); > +} > + > +static inline bool sprd_wdt_is_running(struct sprd_wdt *wdt) > +{ > + u32 val; > + > + val = readl_relaxed(wdt->base + WDT_CTRL); > + return val & WDT_NEW_VER_EN; > +} > + > +static irqreturn_t sprd_wdt_isr(int irq, void *dev_id) > +{ > + struct sprd_wdt *wdt = (struct sprd_wdt *)dev_id; > + > + sprd_wdt_unlock(wdt->base); > + writel_relaxed(WDT_INT_CLEAR_BIT, wdt->base + WDT_INT_CLR); > + sprd_wdt_lock(wdt->base); > + watchdog_notify_pretimeout(&wdt->wdd); > + return IRQ_HANDLED; > +} > + > +static u32 sprd_wdt_get_cnt_value(struct sprd_wdt *wdt) > +{ > + u32 val; > + > + val = readl_relaxed(wdt->base + WDT_CNT_HIGH) << WDT_CNT_VALUE_SIZE; > + val |= readl_relaxed(wdt->base + WDT_CNT_LOW) & WDT_CNT_VALUE_MASK; > + > + return val; > +} > + > +static int sprd_wdt_load_value(struct sprd_wdt *wdt, u32 timeout, > + u32 pretimeout) > +{ > + u32 val, cnt = 0; > + > + if (timeout < pretimeout) > + return -EINVAL; > + This is the wrong place to check if the timeout is valid. The core should know about limits and perform the checks. > + if (!pretimeout) > + pretimeout = WDT_DEFAULT_PRETMROUT; > + If pretimeout was 0 and timeout < 3, this will accept the timeout. If the pretimeout is mandatory, it should be enforced, and the minimum timeout should be larger than the miniumum pretimeout. > + sprd_wdt_unlock(wdt->base); > + writel_relaxed(((timeout * WDT_CLK) >> WDT_CNT_VALUE_SIZE) & > + WDT_CNT_VALUE_MASK, wdt->base + WDT_LOAD_HIGH); This can overflow. The maximum timeout must be <= 0xffffffff / WDT_CLK. > + writel_relaxed(((timeout * WDT_CLK) & WDT_CNT_VALUE_MASK), > + wdt->base + WDT_LOAD_LOW); > + writel_relaxed(((pretimeout * WDT_CLK) >> WDT_CNT_VALUE_SIZE) & > + WDT_CNT_VALUE_MASK, wdt->base + WDT_IRQ_LOAD_HIGH); Same for pretimeout. > + writel_relaxed((pretimeout * WDT_CLK) & WDT_CNT_VALUE_MASK, > + wdt->base + WDT_IRQ_LOAD_LOW); > + sprd_wdt_lock(wdt->base); > + > + /* > + * Waiting the load value operation done, > + * it needs two or three RTC clock cycles. > + */ > + do { > + val = readl_relaxed(wdt->base + WDT_INT_RAW); > + if (!(val & WDT_LD_BUSY_BIT)) > + break; > + > + cpu_relax(); > + } while (cnt++ < WDT_LOAD_TIMEOUT_NUM); > + > + if (cnt >= WDT_LOAD_TIMEOUT_NUM) > + return -EBUSY; > + return 0; > +} > + > +static void sprd_wdt_enable(struct sprd_wdt *wdt) > +{ > + u32 val; > + > + clk_prepare_enable(wdt->enable); > + clk_prepare_enable(wdt->rtc_enable); Both functions can fail. > + > + sprd_wdt_unlock(wdt->base); > + val = readl_relaxed(wdt->base + WDT_CTRL); > + val |= WDT_NEW_VER_EN; > + writel_relaxed(val, wdt->base + WDT_CTRL); > + sprd_wdt_lock(wdt->base); > + set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); Why ? The watchdog isn't started here. > +} > + > +static void sprd_wdt_disable(struct sprd_wdt *wdt) > +{ > + sprd_wdt_unlock(wdt->base); > + writel_relaxed(0x0, wdt->base + WDT_CTRL); > + sprd_wdt_lock(wdt->base); > + > + clk_disable(wdt->enable); > + clk_disable(wdt->rtc_enable); clk_prepare_enable but no matching clk_disable_unprepare ? > +} > + > +static int sprd_wdt_start(struct watchdog_device *wdd) > +{ > + struct sprd_wdt *wdt = to_sprd_wdt(wdd); > + u32 val; > + int ret; > + > + ret = sprd_wdt_load_value(wdt, wdd->timeout, wdd->pretimeout); > + if (ret) > + return ret; > + > + sprd_wdt_unlock(wdt->base); > + val = readl_relaxed(wdt->base + WDT_CTRL); > + val |= WDT_CNT_EN_BIT | WDT_INT_EN_BIT | WDT_RST_EN_BIT; > + writel_relaxed(val, wdt->base + WDT_CTRL); > + sprd_wdt_lock(wdt->base); > + set_bit(WDOG_HW_RUNNING, &wdd->status); > + > + return 0; > +} > + > +static int sprd_wdt_stop(struct watchdog_device *wdd) > +{ > + struct sprd_wdt *wdt = to_sprd_wdt(wdd); > + u32 val; > + > + sprd_wdt_unlock(wdt->base); > + val = readl_relaxed(wdt->base + WDT_CTRL); > + val &= ~(WDT_CNT_EN_BIT | WDT_RST_EN_BIT | WDT_INT_EN_BIT); > + writel_relaxed(val, wdt->base + WDT_CTRL); > + sprd_wdt_lock(wdt->base); > + return 0; > +} > + > +static int sprd_wdt_set_timeout(struct watchdog_device *wdd, > + u32 timeout) > +{ > + struct sprd_wdt *wdt = to_sprd_wdt(wdd); > + > + wdd->timeout = timeout; > + > + return sprd_wdt_load_value(wdt, timeout, wdd->pretimeout); Even on error, this accepts the new (bad) timeout. > +} > + > +static int sprd_wdt_set_pretimeout(struct watchdog_device *wdd, > + u32 new_pretimeout) > +{ > + struct sprd_wdt *wdt = to_sprd_wdt(wdd); > + > + wdd->pretimeout = new_pretimeout; > + > + return sprd_wdt_load_value(wdt, wdd->timeout, new_pretimeout); Even on error, this accepts the new (bad) pretimeout. > +} > + > +static u32 sprd_wdt_get_timeleft(struct watchdog_device *wdd) > +{ > + struct sprd_wdt *wdt = to_sprd_wdt(wdd); > + u32 val; > + > + val = sprd_wdt_get_cnt_value(wdt); > + val = val / WDT_CLK; > + > + return val; > +} > + > +static const struct watchdog_ops sprd_wdt_ops = { > + .owner = THIS_MODULE, > + .start = sprd_wdt_start, > + .stop = sprd_wdt_stop, > + .set_timeout = sprd_wdt_set_timeout, > + .set_pretimeout = sprd_wdt_set_pretimeout, > + .get_timeleft = sprd_wdt_get_timeleft, > +}; > + > +static const struct watchdog_info sprd_wdt_info = { > + .options = WDIOF_SETTIMEOUT | > + WDIOF_PRETIMEOUT | > + WDIOF_MAGICCLOSE | > + WDIOF_KEEPALIVEPING, > + .identity = "Spreadtrum Watchdog Timer", > +}; > + > +static int sprd_wdt_probe(struct platform_device *pdev) > +{ > + struct resource *wdt_res; > + struct sprd_wdt *wdt; > + int ret; > + > + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); > + if (!wdt) > + return -ENOMEM; > + > + wdt_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!wdt_res) { > + dev_err(&pdev->dev, "failed to memory resource\n"); > + return -ENOMEM; > + } > + > + wdt->base = devm_ioremap_nocache(&pdev->dev, wdt_res->start, > + resource_size(wdt_res)); Consider using devm_ioremap_resource(). > + if (!wdt->base) > + return -ENOMEM; > + > + wdt->enable = devm_clk_get(&pdev->dev, "enable"); > + if (IS_ERR(wdt->enable)) { > + dev_err(&pdev->dev, "can't get the enable clock\n"); > + return PTR_ERR(wdt->enable); > + } > + > + wdt->rtc_enable = devm_clk_get(&pdev->dev, "rtc_enable"); > + if (IS_ERR(wdt->rtc_enable)) { > + dev_err(&pdev->dev, "can't get the rtc enable clock\n"); > + return PTR_ERR(wdt->rtc_enable); > + } > + > + wdt->irq = platform_get_irq(pdev, 0); > + if (wdt->irq < 0) { > + dev_err(&pdev->dev, "failed to get IRQ resource\n"); > + return wdt->irq; > + } > + > + ret = devm_request_irq(&pdev->dev, wdt->irq, sprd_wdt_isr, > + IRQF_NO_SUSPEND, "sprd-wdt", (void *)wdt); > + if (ret) { > + dev_err(&pdev->dev, "failed to register irq\n"); > + return ret; > + } > + > + wdt->wdd.info = &sprd_wdt_info; > + wdt->wdd.ops = &sprd_wdt_ops; > + wdt->wdd.parent = &pdev->dev; > + This should also set limits for min/max to let the core validate ranges. If the minimum pretimeout is 3 seconds, the lower limit for timeout should be set accordingly. > + sprd_wdt_enable(wdt); > + > + watchdog_init_timeout(&wdt->wdd, 0, &pdev->dev); > + > + ret = watchdog_register_device(&wdt->wdd); > + if (ret) { > + dev_err(&pdev->dev, "failed to register watchdog\n"); No wdt disable on error ? > + return ret; > + } > + platform_set_drvdata(pdev, wdt); > + > + return 0; > +} > + > +static int sprd_wdt_remove(struct platform_device *pdev) > +{ > + struct sprd_wdt *wdt = platform_get_drvdata(pdev); > + > + if (sprd_wdt_is_running(wdt)) { > + sprd_wdt_stop(&wdt->wdd); > + sprd_wdt_disable(wdt); > + } I assume you understand that this defeats NOWAYOUT. > + watchdog_unregister_device(&wdt->wdd); > + > + return 0; > +} > + > +static int __maybe_unused sprd_wdt_pm_suspend(struct device *dev) > +{ > + struct sprd_wdt *wdt = dev_get_drvdata(dev); > + > + if (sprd_wdt_is_running(wdt)) { if (watchdog_active()) should work here. > + sprd_wdt_stop(&wdt->wdd); > + sprd_wdt_disable(wdt); > + } > + > + return 0; > +} > + > +static int __maybe_unused sprd_wdt_pm_resume(struct device *dev) > +{ > + struct watchdog_device *wdd = dev_get_drvdata(dev); > + struct sprd_wdt *wdt = dev_get_drvdata(dev); > + > + if (watchdog_active(wdd) && !sprd_wdt_is_running(wdt)) { sprd_wdt_is_running() should not be needed. > + sprd_wdt_enable(wdt); > + sprd_wdt_start(&wdt->wdd); > + } > + > + return 0; > +} > + > +static const struct dev_pm_ops sprd_wdt_pm_ops = { > + SET_SYSTEM_SLEEP_PM_OPS(sprd_wdt_pm_suspend, > + sprd_wdt_pm_resume) > +}; > + > +static const struct of_device_id sprd_wdt_match_table[] = { > + { .compatible = "sprd,sp9860-wdt", }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, sprd_wdt_match_table); > + > +static struct platform_driver sprd_watchdog_driver = { > + .probe = sprd_wdt_probe, > + .remove = sprd_wdt_remove, > + .driver = { > + .name = "sprd-wdt", > + .of_match_table = sprd_wdt_match_table, > + .pm = &sprd_wdt_pm_ops, > + }, > +}; > +module_platform_driver(sprd_watchdog_driver); > + > +MODULE_AUTHOR("Eric Long <eric.long@xxxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Spreadtrum Watchdog Timer Controller Driver"); > +MODULE_LICENSE("GPL v2"); -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
