| Message ID | 1536325173-16617-9-git-send-email-p.paillet@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce STPMIC1 PMIC Driver | expand |
On 09/07/2018 05:59 AM, Pascal PAILLET-LME wrote: > From: pascal paillet <p.paillet@st.com> > > The stpmic1 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> > --- > changes in v2: > * the hardware component has been renamed from stpmu1 to stpmic1 ! > * change headers > * handle remarks from Guenter Hmm ... as if I would remember what those were. > * fix set timeout > > drivers/watchdog/Kconfig | 12 ++++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/stpmic1_wdt.c | 130 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 143 insertions(+) > create mode 100644 drivers/watchdog/stpmic1_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 9af07fd..11c5937 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 STPMIC1_WATCHDOG > + tristate "STPMIC1 PMIC watchdog support" > + depends on MFD_STPMIC1 > + select WATCHDOG_CORE > + help > + Say Y here to include watchdog support embedded into STPMIC1 PMIC. > + If the watchdog timer expires, stpmic1 shut-down all its power > + supplies. > + > + To compile this driver as a module, choose M here: the > + module will be called spmic1_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..a898d8f 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_STPMIC1_WATCHDOG) += stpmic1_wdt.o > diff --git a/drivers/watchdog/stpmic1_wdt.c b/drivers/watchdog/stpmic1_wdt.c > new file mode 100644 > index 0000000..391e544 > --- /dev/null > +++ b/drivers/watchdog/stpmic1_wdt.c > @@ -0,0 +1,130 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// Copyright (C) STMicroelectronics 2018 > +// Author: Pascal Paillet <p.paillet@st.com> for STMicroelectronics. > + > +#include <linux/kernel.h> > +#include <linux/mfd/stpmic1.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 stpmic1_wdt { > + struct stpmic1_dev *pmic; > + struct watchdog_device wdtdev; > +}; > + > +static int pmic_wdt_start(struct watchdog_device *wdd) > +{ > + struct stpmic1_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 stpmic1_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 stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); > + > + return regmap_update_bits(wdt->pmic->regmap, > + WCHDG_CR, WDT_PING_MASK, WDT_PING); > +} > + > +static int pmic_wdt_set_timeout(struct watchdog_device *wdd, > + unsigned int timeout) > +{ > + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); > + > + return regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout - 1); What happens if the configured timeout is 1 ? Does that translate to a 1-second timeout ? This function also has to set wdd->timeout. > +} > + > +static const struct watchdog_info pmic_watchdog_info = { > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, No WDIOF_MAGICCLOSE ? > + .identity = "STPMIC1 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 stpmic1_dev *pmic; > + struct stpmic1_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 stpmic1_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_MIN_TIMEOUT; Are you sure about that ? A timeout of 1 second may be a cause for unexpected reboots if user space is busy. Personally I find it better to set a larger default and let userspace configure a tighter value if so desired. Also, watchdog_init_timeout(&wdt->wdtdev, 0, &pdev->dev); might be desirable if you want to be able to specify the timeout in the devicetree file. > + > + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; > + > + watchdog_set_drvdata(&wdt->wdtdev, wdt); > + dev_set_drvdata(&pdev->dev, wdt); Unless I am missing something this should not be needed. > + > + ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev); > + if (ret) > + return ret; > + > + dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n"); > + return 0; > +} > + > +static const struct of_device_id of_pmic_wdt_match[] = { > + { .compatible = "st,stpmic1-wdt" }, > + { }, > +}; > + > +MODULE_DEVICE_TABLE(of, of_pmic_wdt_match); > + > +static struct platform_driver stpmic1_wdt_driver = { > + .probe = pmic_wdt_probe, > + .driver = { > + .name = "stpmic1-wdt", > + .of_match_table = of_pmic_wdt_match, > + }, > +}; > +module_platform_driver(stpmic1_wdt_driver); > + > +MODULE_DESCRIPTION("Watchdog driver for STPMIC1 device"); > +MODULE_AUTHOR("Pascal Paillet"); > +MODULE_LICENSE("GPL v2"); >
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 9af07fd..11c5937 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 STPMIC1_WATCHDOG + tristate "STPMIC1 PMIC watchdog support" + depends on MFD_STPMIC1 + select WATCHDOG_CORE + help + Say Y here to include watchdog support embedded into STPMIC1 PMIC. + If the watchdog timer expires, stpmic1 shut-down all its power + supplies. + + To compile this driver as a module, choose M here: the + module will be called spmic1_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..a898d8f 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_STPMIC1_WATCHDOG) += stpmic1_wdt.o diff --git a/drivers/watchdog/stpmic1_wdt.c b/drivers/watchdog/stpmic1_wdt.c new file mode 100644 index 0000000..391e544 --- /dev/null +++ b/drivers/watchdog/stpmic1_wdt.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) STMicroelectronics 2018 +// Author: Pascal Paillet <p.paillet@st.com> for STMicroelectronics. + +#include <linux/kernel.h> +#include <linux/mfd/stpmic1.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 stpmic1_wdt { + struct stpmic1_dev *pmic; + struct watchdog_device wdtdev; +}; + +static int pmic_wdt_start(struct watchdog_device *wdd) +{ + struct stpmic1_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 stpmic1_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 stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_PING_MASK, WDT_PING); +} + +static int pmic_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout - 1); +} + +static const struct watchdog_info pmic_watchdog_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "STPMIC1 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 stpmic1_dev *pmic; + struct stpmic1_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 stpmic1_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_MIN_TIMEOUT; + + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; + + watchdog_set_drvdata(&wdt->wdtdev, wdt); + dev_set_drvdata(&pdev->dev, wdt); + + ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev); + if (ret) + return ret; + + dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n"); + return 0; +} + +static const struct of_device_id of_pmic_wdt_match[] = { + { .compatible = "st,stpmic1-wdt" }, + { }, +}; + +MODULE_DEVICE_TABLE(of, of_pmic_wdt_match); + +static struct platform_driver stpmic1_wdt_driver = { + .probe = pmic_wdt_probe, + .driver = { + .name = "stpmic1-wdt", + .of_match_table = of_pmic_wdt_match, + }, +}; +module_platform_driver(stpmic1_wdt_driver); + +MODULE_DESCRIPTION("Watchdog driver for STPMIC1 device"); +MODULE_AUTHOR("Pascal Paillet"); +MODULE_LICENSE("GPL v2");