| Message ID | 1530803657-17684-9-git-send-email-p.paillet@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/05/2018 08:14 AM, Pascal PAILLET-LME wrote: > From: pascal paillet <p.paillet@st.com> > > The stpmu1 PMIC embeds a watchdog which is disabled by default. As soon > as the watchdog is started, it must be refreshed periodically otherwise > the PMIC goes off. > > Signed-off-by: pascal paillet <p.paillet@st.com> > --- > drivers/watchdog/Kconfig | 12 +++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/stpmu1_wdt.c | 177 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 190 insertions(+) > create mode 100644 drivers/watchdog/stpmu1_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 9af07fd..2155f4d 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -796,6 +796,18 @@ config STM32_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called stm32_iwdg. > > +config STPMU1_WATCHDOG > + tristate "STPMU1 PMIC watchdog support" > + depends on MFD_STPMU1 > + select WATCHDOG_CORE > + help > + Say Y here to include watchdog support embedded into STPMU1 PMIC. > + If the watchdog timer expires, stpmu1 shut-down all its power > + supplies. > + > + To compile this driver as a module, choose M here: the > + module will be called spmu1_wdt. > + > config UNIPHIER_WATCHDOG > tristate "UniPhier watchdog support" > depends on ARCH_UNIPHIER || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 1d3c6b0..c9eba94 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -216,3 +216,4 @@ obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o > obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o > obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o > obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o > +obj-$(CONFIG_STPMU1_WATCHDOG) += stpmu1_wdt.o > diff --git a/drivers/watchdog/stpmu1_wdt.c b/drivers/watchdog/stpmu1_wdt.c > new file mode 100644 > index 0000000..57e0afa > --- /dev/null > +++ b/drivers/watchdog/stpmu1_wdt.c > @@ -0,0 +1,177 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (C) STMicroelectronics 2018 - All Rights Reserved > + * Author: Philippe Peurichard <philippe.peurichard@st.com>, > + * Pascal Paillet <p.paillet@st.com> for STMicroelectronics. > + */ > + > +#include <linux/kernel.h> > +#include <linux/mfd/stpmu1.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/of.h> > +#include <linux/regmap.h> > +#include <linux/reboot.h> > +#include <linux/slab.h> > +#include <linux/watchdog.h> > + > +/* WATCHDOG CONTROL REGISTER bit */ > +#define WDT_START BIT(0) > +#define WDT_PING BIT(1) > +#define WDT_START_MASK BIT(0) > +#define WDT_PING_MASK BIT(1) > + > +#define PMIC_WDT_MIN_TIMEOUT 1 > +#define PMIC_WDT_MAX_TIMEOUT 256 > + > +struct stpmu1_wdt { > + struct stpmu1_dev *pmic; > + struct watchdog_device wdtdev; > + struct notifier_block restart_handler; > +}; > + > +static int pmic_wdt_start(struct watchdog_device *wdd) > +{ > + struct stpmu1_wdt *wdt = watchdog_get_drvdata(wdd); > + > + return regmap_update_bits(wdt->pmic->regmap, > + WCHDG_CR, WDT_START_MASK, WDT_START); > +} > + > +static int pmic_wdt_stop(struct watchdog_device *wdd) > +{ > + struct stpmu1_wdt *wdt = watchdog_get_drvdata(wdd); > + > + return regmap_update_bits(wdt->pmic->regmap, > + WCHDG_CR, WDT_START_MASK, ~WDT_START); > +} > + > +static int pmic_wdt_ping(struct watchdog_device *wdd) > +{ > + struct stpmu1_wdt *wdt = watchdog_get_drvdata(wdd); > + int ret; > + > + return regmap_update_bits(wdt->pmic->regmap, > + WCHDG_CR, WDT_PING_MASK, WDT_PING); > + return ret; > +} > + > +static int pmic_wdt_set_timeout(struct watchdog_device *wdd, > + unsigned int timeout) > +{ > + struct stpmu1_wdt *wdt = watchdog_get_drvdata(wdd); > + int ret; > + > + ret = regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout); > + if (ret) > + dev_err(wdt->pmic->dev, > + "Failed to set watchdog timeout (err = %d)\n", ret); > + else > + wdd->timeout = PMIC_WDT_MAX_TIMEOUT; First the requested timeout is set, then the caller is notified that the timeout was set to the maximum possible value ? That doesn't make sense. If that is really intentional, I would expect a detailed explanation, and I would expect that the value written into the chip register matches the value reported back to the user. > + > + return ret; > +} > + > +static int pmic_wdt_restart_handler(struct notifier_block *this, > + unsigned long mode, void *cmd) > +{ > + struct stpmu1_wdt *wdt = container_of(this, > + struct stpmu1_wdt, > + restart_handler); > + > + dev_info(wdt->pmic->dev, > + "PMIC Watchdog Elapsed (timeout %d), shutdown of PMIC initiated\n", > + wdt->wdtdev.timeout); > + Register a restart handler just to issue a message ? That is quite pointless. A restart handler is supposed to restart the system. Besides, the message is highly misleading; there is no reason to believe that it will be called after the watchdog expired. This function should restart the system. If it doesn't, drop it. > + return NOTIFY_DONE; > +} > + > +static const struct watchdog_info pmic_watchdog_info = { > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, > + .identity = "STPMU1 PMIC Watchdog", > +}; > + > +static const struct watchdog_ops pmic_watchdog_ops = { > + .owner = THIS_MODULE, > + .start = pmic_wdt_start, > + .stop = pmic_wdt_stop, > + .ping = pmic_wdt_ping, > + .set_timeout = pmic_wdt_set_timeout, > +}; > + > +static int pmic_wdt_probe(struct platform_device *pdev) > +{ > + int ret; > + struct stpmu1_dev *pmic; > + struct stpmu1_wdt *wdt; > + > + if (!pdev->dev.parent) > + return -EINVAL; > + > + pmic = dev_get_drvdata(pdev->dev.parent); > + if (!pmic) > + return -EINVAL; > + > + wdt = devm_kzalloc(&pdev->dev, sizeof(struct stpmu1_wdt), GFP_KERNEL); > + if (!wdt) > + return -ENOMEM; > + > + wdt->pmic = pmic; > + > + wdt->wdtdev.info = &pmic_watchdog_info; > + wdt->wdtdev.ops = &pmic_watchdog_ops; > + wdt->wdtdev.min_timeout = PMIC_WDT_MIN_TIMEOUT; > + wdt->wdtdev.max_timeout = PMIC_WDT_MAX_TIMEOUT; > + wdt->wdtdev.timeout = PMIC_WDT_MAX_TIMEOUT; 256 seconds default timeout ? Unusual, just making sure that this is what you want. > + > + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; > + > + watchdog_set_drvdata(&wdt->wdtdev, wdt); > + dev_set_drvdata(&pdev->dev, wdt); > + > + ret = watchdog_register_device(&wdt->wdtdev); > + if (ret) > + return ret; > + > + wdt->restart_handler.notifier_call = pmic_wdt_restart_handler; > + wdt->restart_handler.priority = 128; > + ret = register_restart_handler(&wdt->restart_handler); Why is the restart handler provided by the watchdog core not sufficient ? > + if (ret) { > + dev_err(wdt->pmic->dev, "failed to register restart handler\n"); > + return ret; > + } > + > + dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n"); The only reasons not to use the devm_ function to register the watchdog are the restart handler, which 1) doesn't do anything and 2) should use the watchdog core, and this debug message. I would suggest to use the devm_ function to register the watchdog instead. > + return 0; > +} > + > +static int pmic_wdt_remove(struct platform_device *pdev) > +{ > + struct stpmu1_wdt *wdt = dev_get_drvdata(&pdev->dev); > + > + unregister_restart_handler(&wdt->restart_handler); > + watchdog_unregister_device(&wdt->wdtdev); > + > + return 0; > +} > + > +static const struct of_device_id of_pmic_wdt_match[] = { > + { .compatible = "st,stpmu1-wdt" }, > + { }, > +}; > + > +MODULE_DEVICE_TABLE(of, of_pmic_wdt_match); > + > +static struct platform_driver stpmu1_wdt_driver = { > + .probe = pmic_wdt_probe, > + .remove = pmic_wdt_remove, > + .driver = { > + .name = "stpmu1-wdt", > + .of_match_table = of_pmic_wdt_match, > + }, > +}; > +module_platform_driver(stpmu1_wdt_driver); > + > +MODULE_AUTHOR("philippe.peurichard@st.com>"); > +MODULE_DESCRIPTION("Watchdog driver for STPMU1 device"); > +MODULE_LICENSE("GPL"); > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 9af07fd..2155f4d 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -796,6 +796,18 @@ config STM32_WATCHDOG To compile this driver as a module, choose M here: the module will be called stm32_iwdg. +config STPMU1_WATCHDOG + tristate "STPMU1 PMIC watchdog support" + depends on MFD_STPMU1 + select WATCHDOG_CORE + help + Say Y here to include watchdog support embedded into STPMU1 PMIC. + If the watchdog timer expires, stpmu1 shut-down all its power + supplies. + + To compile this driver as a module, choose M here: the + module will be called spmu1_wdt. + config UNIPHIER_WATCHDOG tristate "UniPhier watchdog support" depends on ARCH_UNIPHIER || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 1d3c6b0..c9eba94 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -216,3 +216,4 @@ obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o +obj-$(CONFIG_STPMU1_WATCHDOG) += stpmu1_wdt.o diff --git a/drivers/watchdog/stpmu1_wdt.c b/drivers/watchdog/stpmu1_wdt.c new file mode 100644 index 0000000..57e0afa --- /dev/null +++ b/drivers/watchdog/stpmu1_wdt.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) STMicroelectronics 2018 - All Rights Reserved + * Author: Philippe Peurichard <philippe.peurichard@st.com>, + * Pascal Paillet <p.paillet@st.com> for STMicroelectronics. + */ + +#include <linux/kernel.h> +#include <linux/mfd/stpmu1.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/regmap.h> +#include <linux/reboot.h> +#include <linux/slab.h> +#include <linux/watchdog.h> + +/* WATCHDOG CONTROL REGISTER bit */ +#define WDT_START BIT(0) +#define WDT_PING BIT(1) +#define WDT_START_MASK BIT(0) +#define WDT_PING_MASK BIT(1) + +#define PMIC_WDT_MIN_TIMEOUT 1 +#define PMIC_WDT_MAX_TIMEOUT 256 + +struct stpmu1_wdt { + struct stpmu1_dev *pmic; + struct watchdog_device wdtdev; + struct notifier_block restart_handler; +}; + +static int pmic_wdt_start(struct watchdog_device *wdd) +{ + struct stpmu1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_START_MASK, WDT_START); +} + +static int pmic_wdt_stop(struct watchdog_device *wdd) +{ + struct stpmu1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_START_MASK, ~WDT_START); +} + +static int pmic_wdt_ping(struct watchdog_device *wdd) +{ + struct stpmu1_wdt *wdt = watchdog_get_drvdata(wdd); + int ret; + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_PING_MASK, WDT_PING); + return ret; +} + +static int pmic_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct stpmu1_wdt *wdt = watchdog_get_drvdata(wdd); + int ret; + + ret = regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout); + if (ret) + dev_err(wdt->pmic->dev, + "Failed to set watchdog timeout (err = %d)\n", ret); + else + wdd->timeout = PMIC_WDT_MAX_TIMEOUT; + + return ret; +} + +static int pmic_wdt_restart_handler(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + struct stpmu1_wdt *wdt = container_of(this, + struct stpmu1_wdt, + restart_handler); + + dev_info(wdt->pmic->dev, + "PMIC Watchdog Elapsed (timeout %d), shutdown of PMIC initiated\n", + wdt->wdtdev.timeout); + + return NOTIFY_DONE; +} + +static const struct watchdog_info pmic_watchdog_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "STPMU1 PMIC Watchdog", +}; + +static const struct watchdog_ops pmic_watchdog_ops = { + .owner = THIS_MODULE, + .start = pmic_wdt_start, + .stop = pmic_wdt_stop, + .ping = pmic_wdt_ping, + .set_timeout = pmic_wdt_set_timeout, +}; + +static int pmic_wdt_probe(struct platform_device *pdev) +{ + int ret; + struct stpmu1_dev *pmic; + struct stpmu1_wdt *wdt; + + if (!pdev->dev.parent) + return -EINVAL; + + pmic = dev_get_drvdata(pdev->dev.parent); + if (!pmic) + return -EINVAL; + + wdt = devm_kzalloc(&pdev->dev, sizeof(struct stpmu1_wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->pmic = pmic; + + wdt->wdtdev.info = &pmic_watchdog_info; + wdt->wdtdev.ops = &pmic_watchdog_ops; + wdt->wdtdev.min_timeout = PMIC_WDT_MIN_TIMEOUT; + wdt->wdtdev.max_timeout = PMIC_WDT_MAX_TIMEOUT; + wdt->wdtdev.timeout = PMIC_WDT_MAX_TIMEOUT; + + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; + + watchdog_set_drvdata(&wdt->wdtdev, wdt); + dev_set_drvdata(&pdev->dev, wdt); + + ret = watchdog_register_device(&wdt->wdtdev); + if (ret) + return ret; + + wdt->restart_handler.notifier_call = pmic_wdt_restart_handler; + wdt->restart_handler.priority = 128; + ret = register_restart_handler(&wdt->restart_handler); + if (ret) { + dev_err(wdt->pmic->dev, "failed to register restart handler\n"); + return ret; + } + + dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n"); + return 0; +} + +static int pmic_wdt_remove(struct platform_device *pdev) +{ + struct stpmu1_wdt *wdt = dev_get_drvdata(&pdev->dev); + + unregister_restart_handler(&wdt->restart_handler); + watchdog_unregister_device(&wdt->wdtdev); + + return 0; +} + +static const struct of_device_id of_pmic_wdt_match[] = { + { .compatible = "st,stpmu1-wdt" }, + { }, +}; + +MODULE_DEVICE_TABLE(of, of_pmic_wdt_match); + +static struct platform_driver stpmu1_wdt_driver = { + .probe = pmic_wdt_probe, + .remove = pmic_wdt_remove, + .driver = { + .name = "stpmu1-wdt", + .of_match_table = of_pmic_wdt_match, + }, +}; +module_platform_driver(stpmu1_wdt_driver); + +MODULE_AUTHOR("philippe.peurichard@st.com>"); +MODULE_DESCRIPTION("Watchdog driver for STPMU1 device"); +MODULE_LICENSE("GPL");