Messages in this thread | | | Date | Sun, 2 Jan 2022 17:14:42 +0100 | Subject | Re: [PATCH v4 2/2] watchdog: Add watchdog driver for Sunplus SP7021 | From | Christophe JAILLET <> |
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Le 02/01/2022 à 16:00, Guenter Roeck a écrit : > On Wed, Dec 29, 2021 at 01:43:08PM +0800, Xiantao Hu wrote: >> Sunplus SP7021 requires watchdog timer support. >> Add watchdog driver to enable this. >> >> Signed-off-by: Xiantao Hu <xt.hu@cqplus1.com> >> --- >> Changes in v4 >> - Drop the unused varible struct resource *wdt_res. >> - Drop the operations related to address 0x9c000274. >> Put it in bootloader before entry kernel boot in v3. >> >> MAINTAINERS | 1 + >> drivers/watchdog/Kconfig | 11 ++ >> drivers/watchdog/Makefile | 1 + >> drivers/watchdog/sunplus_wdt.c | 278 +++++++++++++++++++++++++++++++++ >> 4 files changed, 291 insertions(+) >> create mode 100644 drivers/watchdog/sunplus_wdt.c >> >> diff --git a/MAINTAINERS b/MAINTAINERS >> index fe6cc971c..a1b3d76e2 100644 >> --- a/MAINTAINERS >> +++ b/MAINTAINERS >> @@ -18247,6 +18247,7 @@ M: Xiantao Hu <xt.hu@cqplus1.com> >> L: linux-watchdog@vger.kernel.org >> S: Maintained >> F: Documentation/devicetree/bindings/watchdog/sunplus,sp7021-wdt.yaml >> +F: drivers/watchdog/sunplus_wdt.c >> >> SUPERH >> M: Yoshinori Sato <ysato@users.sourceforge.jp> >> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig >> index 9d222ba17..d3dbe8695 100644 >> --- a/drivers/watchdog/Kconfig >> +++ b/drivers/watchdog/Kconfig >> @@ -976,6 +976,17 @@ config MSC313E_WATCHDOG >> To compile this driver as a module, choose M here: the >> module will be called msc313e_wdt. >> >> +config SUNPLUS_WATCHDOG >> + tristate "Sunplus watchdog support" >> + depends on ARCH_SUNPLUS || COMPILE_TEST >> + select WATCHDOG_CORE >> + help >> + Say Y here to include support for the watchdog timer >> + in Sunplus SoCs. >> + >> + To compile this driver as a module, choose M here: the >> + module will be called sunplus_wdt. >> + >> # X86 (i386 + ia64 + x86_64) Architecture >> >> config ACQUIRE_WDT >> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile >> index 2ee970641..0fa548ee6 100644 >> --- a/drivers/watchdog/Makefile >> +++ b/drivers/watchdog/Makefile >> @@ -93,6 +93,7 @@ obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o >> obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o >> obj-$(CONFIG_VISCONTI_WATCHDOG) += visconti_wdt.o >> obj-$(CONFIG_MSC313E_WATCHDOG) += msc313e_wdt.o >> +obj-$(CONFIG_SUNPLUS_WATCHDOG) += sunplus_wdt.o >> >> # X86 (i386 + ia64 + x86_64) Architecture >> obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o >> diff --git a/drivers/watchdog/sunplus_wdt.c b/drivers/watchdog/sunplus_wdt.c >> new file mode 100644 >> index 000000000..9fae7a14b >> --- /dev/null >> +++ b/drivers/watchdog/sunplus_wdt.c >> @@ -0,0 +1,278 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * sunplus Watchdog Driver >> + * >> + * Copyright (C) 2021 Sunplus Technology Co., Ltd. >> + * >> + */ >> + >> +#include <linux/clk.h> >> +#include <linux/io.h> >> +#include <linux/module.h> >> +#include <linux/mod_devicetable.h> >> +#include <linux/platform_device.h> >> +#include <linux/reset.h> >> +#include <linux/watchdog.h> >> + >> +#define WDT_CTRL 0x00 >> +#define WDT_CNT 0x04 >> + >> +#define WDT_STOP 0x3877 >> +#define WDT_RESUME 0x4A4B >> +#define WDT_CLRIRQ 0x7482 >> +#define WDT_UNLOCK 0xAB00 >> +#define WDT_LOCK 0xAB01 >> +#define WDT_CONMAX 0xDEAF >> + >> +#define SP_WDT_MAX_TIMEOUT 11U >> +#define SP_WDT_DEFAULT_TIMEOUT 10 >> + >> +#define STC_CLK 90000 >> + >> +#define DEVICE_NAME "sunplus-wdt" >> + >> +static unsigned int timeout; >> +module_param(timeout, int, 0); >> +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds"); >> + >> +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 sp_wdt_priv { >> + struct watchdog_device wdev; >> + void __iomem *base; >> + struct clk *clk; >> + struct reset_control *rstc; >> +}; >> + >> +static int sp_wdt_restart(struct watchdog_device *wdev, >> + unsigned long action, void *data) >> +{ >> + struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev); >> + void __iomem *base = priv->base; >> + >> + writel(WDT_STOP, base + WDT_CTRL); >> + writel(WDT_UNLOCK, base + WDT_CTRL); >> + writel(0x0001, base + WDT_CNT); >> + writel(WDT_LOCK, base + WDT_CTRL); >> + writel(WDT_RESUME, base + WDT_CTRL); >> + >> + return 0; >> +} >> + >> +/* TIMEOUT_MAX = ffff0/90kHz =11.65,so longer than 11 seconds will time out */ >> +static int sp_wdt_ping(struct watchdog_device *wdev) >> +{ >> + struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev); >> + void __iomem *base = priv->base; >> + u32 count; >> + u32 actual; >> + >> + actual = min(wdev->timeout, SP_WDT_MAX_TIMEOUT); >> + >> + if (actual > SP_WDT_MAX_TIMEOUT) { >> + writel(WDT_CONMAX, base + WDT_CTRL); >> + } else { >> + writel(WDT_UNLOCK, base + WDT_CTRL); >> + /* tiemrw_cnt[3:0]can't be write,only [19:4] can be write. */ >> + count = (actual * STC_CLK) >> 4; >> + writel(count, base + WDT_CNT); >> + writel(WDT_LOCK, base + WDT_CTRL); >> + } >> + >> + return 0; >> +} >> + >> +static int sp_wdt_set_timeout(struct watchdog_device *wdev, >> + unsigned int timeout) >> +{ >> + wdev->timeout = timeout; >> + sp_wdt_ping(wdev); > > This is exactly what the calling code does if there is no set_timeout > function, so you can just drop this function, > >> + >> + return 0; >> +} >> + >> +static int sp_wdt_stop(struct watchdog_device *wdev) >> +{ >> + struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev); >> + void __iomem *base = priv->base; >> + >> + writel(WDT_STOP, base + WDT_CTRL); >> + >> + return 0; >> +} >> + >> +static int sp_wdt_start(struct watchdog_device *wdev) >> +{ >> + struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev); >> + void __iomem *base = priv->base; >> + >> + writel(WDT_RESUME, base + WDT_CTRL); >> + >> + return 0; >> +} >> + >> +static unsigned int sp_wdt_get_timeleft(struct watchdog_device *wdev) >> +{ >> + struct sp_wdt_priv *priv = watchdog_get_drvdata(wdev); >> + void __iomem *base = priv->base; >> + u32 val; >> + >> + val = readl(base + WDT_CNT); >> + val &= 0xffff; >> + val = val << 4; >> + >> + return val; >> +} >> + >> +static const struct watchdog_info sp_wdt_info = { >> + .identity = DEVICE_NAME, >> + .options = WDIOF_SETTIMEOUT | >> + WDIOF_MAGICCLOSE | >> + WDIOF_KEEPALIVEPING, >> +}; >> + >> +static const struct watchdog_ops sp_wdt_ops = { >> + .owner = THIS_MODULE, >> + .start = sp_wdt_start, >> + .stop = sp_wdt_stop, >> + .ping = sp_wdt_ping, >> + .set_timeout = sp_wdt_set_timeout, >> + .get_timeleft = sp_wdt_get_timeleft, >> + .restart = sp_wdt_restart, >> +}; >> + >> +static void sp_clk_disable_unprepare(void *data) >> +{ >> + clk_disable_unprepare(data); >> +} >> + >> +static void sp_reset_control_assert(void *data) >> +{ >> + reset_control_assert(data); >> +} >> + >> +static int sp_wdt_probe(struct platform_device *pdev) >> +{ >> + struct device *dev = &pdev->dev; >> + struct sp_wdt_priv *priv; >> + int err; >> + >> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); >> + if (!priv) >> + return -ENOMEM; >> + >> + priv->clk = devm_clk_get(dev, NULL); >> + if (IS_ERR(priv->clk)) { >> + dev_err(dev, "Can't find clock source\n"); >> + return PTR_ERR(priv->clk); >> + } >> + >> + err = clk_prepare_enable(priv->clk); >> + if (err) { >> + dev_err(dev, "Clock can't be enabled correctly\n"); >> + return err; >> + } >> + >> + /* The timer and watchdog shared the STC reset */ >> + priv->rstc = devm_reset_control_get_shared(dev, NULL); >> + if (!IS_ERR(priv->rstc)) >> + reset_control_deassert(priv->rstc); >> + >> + err = devm_add_action_or_reset(dev, sp_reset_control_assert, >> + priv->rstc); >> + if (err) >> + return err; >> + > > devm_add_action_or_reset() above should only be called if > devm_reset_control_get_shared succeeds.
I also think that the same "if (!IS_ERR(priv->rstc))" should be done in the suspend/resume function before calling reset_control_[de]assert() Otherwise it will WARN.
CJ
> >> + err = devm_add_action_or_reset(dev, sp_clk_disable_unprepare, >> + priv->clk); > > This should be called immediately after clk_prepare_enable(). > >> + if (err) >> + return err; >> + >> + priv->base = devm_platform_ioremap_resource(pdev, 0); >> + if (IS_ERR(priv->base)) >> + return PTR_ERR(priv->base); >> + >> + priv->wdev.info = &sp_wdt_info; >> + priv->wdev.ops = &sp_wdt_ops; >> + priv->wdev.timeout = SP_WDT_DEFAULT_TIMEOUT; >> + priv->wdev.max_hw_heartbeat_ms = SP_WDT_MAX_TIMEOUT * 1000; >> + priv->wdev.min_timeout = 1; >> + priv->wdev.parent = dev; >> + >> + watchdog_init_timeout(&priv->wdev, timeout, dev); >> + watchdog_set_nowayout(&priv->wdev, nowayout); >> + watchdog_set_restart_priority(&priv->wdev, 128); >> + >> + watchdog_set_drvdata(&priv->wdev, priv); >> + >> + watchdog_stop_on_reboot(&priv->wdev); >> + err = devm_watchdog_register_device(dev, &priv->wdev); >> + if (err) >> + return err; >> + >> + platform_set_drvdata(pdev, priv); >> + >> + dev_info(dev, "Watchdog enabled (timeout=%d sec%s.)\n", >> + priv->wdev.timeout, nowayout ? ", nowayout" : ""); >> + >> + return 0; >> +} >> + >> +static const struct of_device_id sp_wdt_of_match[] = { >> + {.compatible = "sunplus,sp7021-wdt", }, >> + { /* sentinel */ } >> +}; >> +MODULE_DEVICE_TABLE(of, sp_wdt_of_match); >> + >> +static int __maybe_unused sp_wdt_suspend(struct device *dev) >> +{ >> + struct sp_wdt_priv *priv = dev_get_drvdata(dev); >> + >> + if (watchdog_active(&priv->wdev)) >> + sp_wdt_stop(&priv->wdev); >> + >> + reset_control_assert(priv->rstc); >> + clk_disable_unprepare(priv->clk); >> + >> + return 0; >> +} >> + >> +static int __maybe_unused sp_wdt_resume(struct device *dev) >> +{ >> + int err; >> + >> + struct sp_wdt_priv *priv = dev_get_drvdata(dev); >> + >> + err = clk_prepare_enable(priv->clk); >> + if (err) { >> + dev_err(dev, "Clock can't be enabled correctly\n"); >> + return err; >> + } >> + >> + reset_control_deassert(priv->rstc); >> + >> + if (watchdog_active(&priv->wdev)) >> + sp_wdt_start(&priv->wdev); >> + >> + return 0; >> +} >> + >> +static SIMPLE_DEV_PM_OPS(sp_wdt_pm_ops, sp_wdt_suspend, sp_wdt_resume); >> + >> +static struct platform_driver sp_wdt_driver = { >> + .probe = sp_wdt_probe, >> + .driver = { >> + .name = DEVICE_NAME, >> + .of_match_table = sp_wdt_of_match, >> + .pm = &sp_wdt_pm_ops, >> + }, >> +}; >> + >> +module_platform_driver(sp_wdt_driver); >> + >> +MODULE_AUTHOR("Xiantao Hu <xt.hu@cqplus1.com>"); >> +MODULE_DESCRIPTION("Sunplus Watchdog Timer Driver"); >> +MODULE_LICENSE("GPL v2"); >> -- >> 2.33.1 >> >
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