| Message ID | 20220427135531.708279-3-jjhiblot@traphandler.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | ARM: r9a06g032: add support for the watchdogs | expand |
On Wed, Apr 27, 2022 at 03:55:31PM +0200, Jean-Jacques Hiblot wrote: > From: Phil Edworthy <phil.edworthy@renesas.com> > > This is a driver for the standard WDT on the RZ/N1 devices. This WDT has > very limited timeout capabilities. However, it can reset the device. > To do so, the corresponding bits in the SysCtrl RSTEN register need to > be enabled. This is not done by this driver. > > Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com> > Signed-off-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com> > Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/watchdog/Kconfig | 8 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/rzn1_wdt.c | 203 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 212 insertions(+) > create mode 100644 drivers/watchdog/rzn1_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index c4e82a8d863f..4d5e503c8950 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -883,6 +883,14 @@ config RENESAS_RZAWDT > This driver adds watchdog support for the integrated watchdogs in the > Renesas RZ/A SoCs. These watchdogs can be used to reset a system. > > +config RENESAS_RZN1WDT > + tristate "Renesas RZ/N1 watchdog" > + depends on ARCH_RENESAS || COMPILE_TEST > + select WATCHDOG_CORE > + help > + This driver adds watchdog support for the integrated watchdogs in the > + Renesas RZ/N1 SoCs. These watchdogs can be used to reset a system. > + > config RENESAS_RZG2LWDT > tristate "Renesas RZ/G2L WDT Watchdog" > depends on ARCH_RENESAS || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index f7da867e8782..38d38564f47b 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -84,6 +84,7 @@ obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o > obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o > obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o > obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o > +obj-$(CONFIG_RENESAS_RZN1WDT) += rzn1_wdt.o > obj-$(CONFIG_RENESAS_RZG2LWDT) += rzg2l_wdt.o > obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o > obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o > diff --git a/drivers/watchdog/rzn1_wdt.c b/drivers/watchdog/rzn1_wdt.c > new file mode 100644 > index 000000000000..55ab384b9965 > --- /dev/null > +++ b/drivers/watchdog/rzn1_wdt.c > @@ -0,0 +1,203 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Renesas RZ/N1 Watchdog timer. > + * This is a 12-bit timer driver from a (62.5/16384) MHz clock. It can't even > + * cope with 2 seconds. > + * > + * Copyright 2018 Renesas Electronics Europe Ltd. > + * > + * Derived from Ralink RT288x watchdog timer. > + */ > + > +#include <linux/clk.h> > +#include <linux/interrupt.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/of_address.h> > +#include <linux/of_irq.h> > +#include <linux/platform_device.h> > +#include <linux/reboot.h> > +#include <linux/watchdog.h> > + > +#define DEFAULT_TIMEOUT 60 > + > +#define RZN1_WDT_RETRIGGER 0x0 > +#define RZN1_WDT_RETRIGGER_RELOAD_VAL 0 > +#define RZN1_WDT_RETRIGGER_RELOAD_VAL_MASK 0xfff > +#define RZN1_WDT_RETRIGGER_PRESCALE BIT(12) > +#define RZN1_WDT_RETRIGGER_ENABLE BIT(13) > +#define RZN1_WDT_RETRIGGER_WDSI (0x2 << 14) > + > +#define RZN1_WDT_PRESCALER 16384 > +#define RZN1_WDT_MAX 4095 > + > +struct rzn1_watchdog { > + struct watchdog_device wdtdev; > + void __iomem *base; > + unsigned long clk_rate_khz; > +}; > + > +static inline uint32_t max_heart_beat_ms(unsigned long clk_rate_khz) > +{ > + return (RZN1_WDT_MAX * RZN1_WDT_PRESCALER) / clk_rate_khz; > +} > + > +static inline uint32_t compute_reload_value(uint32_t tick_ms, > + unsigned long clk_rate_khz) > +{ > + return (tick_ms * clk_rate_khz) / RZN1_WDT_PRESCALER; > +} > + > +static int rzn1_wdt_ping(struct watchdog_device *w) > +{ > + struct rzn1_watchdog *wdt = watchdog_get_drvdata(w); > + > + /* Any value retrigggers the watchdog */ > + writel(0, wdt->base + RZN1_WDT_RETRIGGER); > + > + return 0; > +} > + > +static int rzn1_wdt_start(struct watchdog_device *w) > +{ > + struct rzn1_watchdog *wdt = watchdog_get_drvdata(w); > + u32 val; > + > + /* > + * The hardware allows you to write to this reg only once. > + * Since this includes the reload value, there is no way to change the > + * timeout once started. Also note that the WDT clock is half the bus > + * fabric clock rate, so if the bus fabric clock rate is changed after > + * the WDT is started, the WDT interval will be wrong. > + */ > + val = RZN1_WDT_RETRIGGER_WDSI; > + val |= RZN1_WDT_RETRIGGER_ENABLE; > + val |= RZN1_WDT_RETRIGGER_PRESCALE; > + val |= compute_reload_value(w->max_hw_heartbeat_ms, wdt->clk_rate_khz); > + writel(val, wdt->base + RZN1_WDT_RETRIGGER); > + > + return 0; > +} > + > +static irqreturn_t rzn1_wdt_irq(int irq, void *_wdt) > +{ > + pr_crit("RZN1 Watchdog. Initiating system reboot\n"); > + emergency_restart(); > + > + return IRQ_HANDLED; > +} > + > +static struct watchdog_info rzn1_wdt_info = { > + .identity = "RZ/N1 Watchdog", > + .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, > +}; > + > +static const struct watchdog_ops rzn1_wdt_ops = { > + .owner = THIS_MODULE, > + .start = rzn1_wdt_start, > + .ping = rzn1_wdt_ping, > +}; > + > +static void rzn1_wdt_clk_disable_unprepare(void *data) > +{ > + clk_disable_unprepare(data); > +} > + > +static int rzn1_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct rzn1_watchdog *wdt; > + struct device_node *np = dev->of_node; > + struct clk *clk; > + unsigned long clk_rate; > + int ret; > + int irq; > + > + 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); > + > + irq = platform_get_irq(pdev, 0); > + if (irq < 0) > + return irq; > + > + ret = devm_request_irq(dev, irq, rzn1_wdt_irq, 0, > + np->name, wdt); > + if (ret) { > + dev_err(dev, "failed to request irq %d\n", irq); > + return ret; > + } > + > + clk = devm_clk_get(dev, NULL); > + if (IS_ERR(clk)) { > + dev_err(dev, "failed to get the clock\n"); > + return PTR_ERR(clk); > + } > + > + ret = clk_prepare_enable(clk); > + if (ret) { > + dev_err(dev, "failed to prepare/enable the clock\n"); > + return ret; > + } > + > + ret = devm_add_action_or_reset(dev, rzn1_wdt_clk_disable_unprepare, > + clk); > + if (ret) > + return ret; > + > + clk_rate = clk_get_rate(clk); > + if (!clk_rate) { > + dev_err(dev, "failed to get the clock rate\n"); > + return -EINVAL; > + } > + > + wdt->clk_rate_khz = clk_rate / 1000; > + wdt->wdtdev.info = &rzn1_wdt_info, > + wdt->wdtdev.ops = &rzn1_wdt_ops, > + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS, > + wdt->wdtdev.parent = dev; > + /* > + * The period of the watchdog cannot be changed once set > + * and is limited to a very short period. > + * Configure it for a 1s period once and for all, and > + * rely on the heart-beat provided by the watchdog core > + * to make this usable by the user-space. > + */ > + wdt->wdtdev.max_hw_heartbeat_ms = max_heart_beat_ms(wdt->clk_rate_khz); > + if (wdt->wdtdev.max_hw_heartbeat_ms > 1000) > + wdt->wdtdev.max_hw_heartbeat_ms = 1000; > + > + wdt->wdtdev.timeout = DEFAULT_TIMEOUT; > + ret = watchdog_init_timeout(&wdt->wdtdev, 0, dev); > + if (ret) > + return ret; > + > + watchdog_set_drvdata(&wdt->wdtdev, wdt); > + > + return devm_watchdog_register_device(dev, &wdt->wdtdev); > +} > + > + > +static const struct of_device_id rzn1_wdt_match[] = { > + { .compatible = "renesas,rzn1-wdt" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, rzn1_wdt_match); > + > +static struct platform_driver rzn1_wdt_driver = { > + .probe = rzn1_wdt_probe, > + .driver = { > + .name = KBUILD_MODNAME, > + .of_match_table = rzn1_wdt_match, > + }, > +}; > + > +module_platform_driver(rzn1_wdt_driver); > + > +MODULE_DESCRIPTION("Renesas RZ/N1 hardware watchdog"); > +MODULE_AUTHOR("Phil Edworthy <phil.edworthy@renesas.com>"); > +MODULE_LICENSE("GPL");
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index c4e82a8d863f..4d5e503c8950 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -883,6 +883,14 @@ config RENESAS_RZAWDT This driver adds watchdog support for the integrated watchdogs in the Renesas RZ/A SoCs. These watchdogs can be used to reset a system. +config RENESAS_RZN1WDT + tristate "Renesas RZ/N1 watchdog" + depends on ARCH_RENESAS || COMPILE_TEST + select WATCHDOG_CORE + help + This driver adds watchdog support for the integrated watchdogs in the + Renesas RZ/N1 SoCs. These watchdogs can be used to reset a system. + config RENESAS_RZG2LWDT tristate "Renesas RZ/G2L WDT Watchdog" depends on ARCH_RENESAS || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index f7da867e8782..38d38564f47b 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -84,6 +84,7 @@ obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o +obj-$(CONFIG_RENESAS_RZN1WDT) += rzn1_wdt.o obj-$(CONFIG_RENESAS_RZG2LWDT) += rzg2l_wdt.o obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o diff --git a/drivers/watchdog/rzn1_wdt.c b/drivers/watchdog/rzn1_wdt.c new file mode 100644 index 000000000000..55ab384b9965 --- /dev/null +++ b/drivers/watchdog/rzn1_wdt.c @@ -0,0 +1,203 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/N1 Watchdog timer. + * This is a 12-bit timer driver from a (62.5/16384) MHz clock. It can't even + * cope with 2 seconds. + * + * Copyright 2018 Renesas Electronics Europe Ltd. + * + * Derived from Ralink RT288x watchdog timer. + */ + +#include <linux/clk.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/watchdog.h> + +#define DEFAULT_TIMEOUT 60 + +#define RZN1_WDT_RETRIGGER 0x0 +#define RZN1_WDT_RETRIGGER_RELOAD_VAL 0 +#define RZN1_WDT_RETRIGGER_RELOAD_VAL_MASK 0xfff +#define RZN1_WDT_RETRIGGER_PRESCALE BIT(12) +#define RZN1_WDT_RETRIGGER_ENABLE BIT(13) +#define RZN1_WDT_RETRIGGER_WDSI (0x2 << 14) + +#define RZN1_WDT_PRESCALER 16384 +#define RZN1_WDT_MAX 4095 + +struct rzn1_watchdog { + struct watchdog_device wdtdev; + void __iomem *base; + unsigned long clk_rate_khz; +}; + +static inline uint32_t max_heart_beat_ms(unsigned long clk_rate_khz) +{ + return (RZN1_WDT_MAX * RZN1_WDT_PRESCALER) / clk_rate_khz; +} + +static inline uint32_t compute_reload_value(uint32_t tick_ms, + unsigned long clk_rate_khz) +{ + return (tick_ms * clk_rate_khz) / RZN1_WDT_PRESCALER; +} + +static int rzn1_wdt_ping(struct watchdog_device *w) +{ + struct rzn1_watchdog *wdt = watchdog_get_drvdata(w); + + /* Any value retrigggers the watchdog */ + writel(0, wdt->base + RZN1_WDT_RETRIGGER); + + return 0; +} + +static int rzn1_wdt_start(struct watchdog_device *w) +{ + struct rzn1_watchdog *wdt = watchdog_get_drvdata(w); + u32 val; + + /* + * The hardware allows you to write to this reg only once. + * Since this includes the reload value, there is no way to change the + * timeout once started. Also note that the WDT clock is half the bus + * fabric clock rate, so if the bus fabric clock rate is changed after + * the WDT is started, the WDT interval will be wrong. + */ + val = RZN1_WDT_RETRIGGER_WDSI; + val |= RZN1_WDT_RETRIGGER_ENABLE; + val |= RZN1_WDT_RETRIGGER_PRESCALE; + val |= compute_reload_value(w->max_hw_heartbeat_ms, wdt->clk_rate_khz); + writel(val, wdt->base + RZN1_WDT_RETRIGGER); + + return 0; +} + +static irqreturn_t rzn1_wdt_irq(int irq, void *_wdt) +{ + pr_crit("RZN1 Watchdog. Initiating system reboot\n"); + emergency_restart(); + + return IRQ_HANDLED; +} + +static struct watchdog_info rzn1_wdt_info = { + .identity = "RZ/N1 Watchdog", + .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, +}; + +static const struct watchdog_ops rzn1_wdt_ops = { + .owner = THIS_MODULE, + .start = rzn1_wdt_start, + .ping = rzn1_wdt_ping, +}; + +static void rzn1_wdt_clk_disable_unprepare(void *data) +{ + clk_disable_unprepare(data); +} + +static int rzn1_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rzn1_watchdog *wdt; + struct device_node *np = dev->of_node; + struct clk *clk; + unsigned long clk_rate; + int ret; + int irq; + + 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); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = devm_request_irq(dev, irq, rzn1_wdt_irq, 0, + np->name, wdt); + if (ret) { + dev_err(dev, "failed to request irq %d\n", irq); + return ret; + } + + clk = devm_clk_get(dev, NULL); + if (IS_ERR(clk)) { + dev_err(dev, "failed to get the clock\n"); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) { + dev_err(dev, "failed to prepare/enable the clock\n"); + return ret; + } + + ret = devm_add_action_or_reset(dev, rzn1_wdt_clk_disable_unprepare, + clk); + if (ret) + return ret; + + clk_rate = clk_get_rate(clk); + if (!clk_rate) { + dev_err(dev, "failed to get the clock rate\n"); + return -EINVAL; + } + + wdt->clk_rate_khz = clk_rate / 1000; + wdt->wdtdev.info = &rzn1_wdt_info, + wdt->wdtdev.ops = &rzn1_wdt_ops, + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS, + wdt->wdtdev.parent = dev; + /* + * The period of the watchdog cannot be changed once set + * and is limited to a very short period. + * Configure it for a 1s period once and for all, and + * rely on the heart-beat provided by the watchdog core + * to make this usable by the user-space. + */ + wdt->wdtdev.max_hw_heartbeat_ms = max_heart_beat_ms(wdt->clk_rate_khz); + if (wdt->wdtdev.max_hw_heartbeat_ms > 1000) + wdt->wdtdev.max_hw_heartbeat_ms = 1000; + + wdt->wdtdev.timeout = DEFAULT_TIMEOUT; + ret = watchdog_init_timeout(&wdt->wdtdev, 0, dev); + if (ret) + return ret; + + watchdog_set_drvdata(&wdt->wdtdev, wdt); + + return devm_watchdog_register_device(dev, &wdt->wdtdev); +} + + +static const struct of_device_id rzn1_wdt_match[] = { + { .compatible = "renesas,rzn1-wdt" }, + {}, +}; +MODULE_DEVICE_TABLE(of, rzn1_wdt_match); + +static struct platform_driver rzn1_wdt_driver = { + .probe = rzn1_wdt_probe, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = rzn1_wdt_match, + }, +}; + +module_platform_driver(rzn1_wdt_driver); + +MODULE_DESCRIPTION("Renesas RZ/N1 hardware watchdog"); +MODULE_AUTHOR("Phil Edworthy <phil.edworthy@renesas.com>"); +MODULE_LICENSE("GPL");