| Message ID | 20211019145919.7327-9-luca@lucaceresoli.net |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | Add MAX77714 PMIC minimal driver (RTC and watchdog only) | expand |
On 10/19/21 7:59 AM, Luca Ceresoli wrote: > Add a simple driver to support the watchdog embedded in the Maxim MAX77714 > PMIC. > > Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net> Acked-by: Guenter Roeck <linux@roeck-us.net> The driver needs the include file introduced with the mfd driver, so I assume it will be submitted through the mfd branch. Thanks, Guenter > > --- > > Changes in v2: > - fix Kconfig help indentation (Randy Dunlap) > - make max77714_margin_value static const (Guenter Roeck) > - fix platform module instantiation > --- > MAINTAINERS | 1 + > drivers/watchdog/Kconfig | 9 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/max77714_wdt.c | 179 ++++++++++++++++++++++++++++++++ > 4 files changed, 190 insertions(+) > create mode 100644 drivers/watchdog/max77714_wdt.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index abd9de8a9d99..71c3d8513ba0 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11391,6 +11391,7 @@ M: Luca Ceresoli <luca@lucaceresoli.net> > S: Maintained > F: Documentation/devicetree/bindings/mfd/maxim,max77714.yaml > F: drivers/mfd/max77714.c > +F: drivers/watchdog/max77714_wdt.c > F: include/linux/mfd/max77714.h > > MAXIM MAX77802 PMIC REGULATOR DEVICE DRIVER > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index a24385099a91..b9b575acd690 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -699,6 +699,15 @@ config MAX77620_WATCHDOG > MAX77620 chips. To compile this driver as a module, > choose M here: the module will be called max77620_wdt. > > +config MAX77714_WATCHDOG > + tristate "Maxim MAX77714 Watchdog Timer" > + depends on MFD_MAX77714 || COMPILE_TEST > + help > + This is the driver for watchdog timer in the MAX77714 PMIC. > + Say 'Y' here to enable the watchdog timer support for MAX77714 > + chips. To compile this driver as a module, choose M here: the > + module will be called max77714_wdt. > + > config IMX2_WDT > tristate "IMX2+ Watchdog" > depends on ARCH_MXC || ARCH_LAYERSCAPE || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 1bd2d6f37c53..268a942311a0 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -215,6 +215,7 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o > obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o > obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o > obj-$(CONFIG_MAX77620_WATCHDOG) += max77620_wdt.o > +obj-$(CONFIG_MAX77714_WATCHDOG) += max77714_wdt.o > obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o > obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o > obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o > diff --git a/drivers/watchdog/max77714_wdt.c b/drivers/watchdog/max77714_wdt.c > new file mode 100644 > index 000000000000..cce6c13d76eb > --- /dev/null > +++ b/drivers/watchdog/max77714_wdt.c > @@ -0,0 +1,179 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Maxim MAX77714 Watchdog Driver > + * > + * Copyright (C) 2021 Luca Ceresoli > + * Author: Luca Ceresoli <luca@lucaceresoli.net> > + */ > + > +#include <linux/err.h> > +#include <linux/kernel.h> > +#include <linux/mfd/max77714.h> > +#include <linux/mod_devicetable.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/watchdog.h> > + > +struct max77714_wdt { > + struct device *dev; > + struct regmap *rmap; > + struct watchdog_device wd_dev; > +}; > + > +/* Timeout in seconds, indexed by TWD bits of CNFG_GLBL2 register */ > +static const unsigned int max77714_margin_value[] = { 2, 16, 64, 128 }; > + > +static int max77714_wdt_start(struct watchdog_device *wd_dev) > +{ > + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); > + > + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, > + MAX77714_WDTEN, MAX77714_WDTEN); > +} > + > +static int max77714_wdt_stop(struct watchdog_device *wd_dev) > +{ > + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); > + > + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, > + MAX77714_WDTEN, 0); > +} > + > +static int max77714_wdt_ping(struct watchdog_device *wd_dev) > +{ > + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); > + > + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL3, > + MAX77714_WDTC, 1); > +} > + > +static int max77714_wdt_set_timeout(struct watchdog_device *wd_dev, > + unsigned int timeout) > +{ > + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); > + unsigned int new_timeout, new_twd; > + int err; > + > + for (new_twd = 0; new_twd < ARRAY_SIZE(max77714_margin_value) - 1; new_twd++) > + if (timeout <= max77714_margin_value[new_twd]) > + break; > + > + /* new_wdt is not out of bounds here due to the "- 1" in the for loop */ > + new_timeout = max77714_margin_value[new_twd]; > + > + /* > + * "If the value of TWD needs to be changed, clear the system > + * watchdog timer first [...], then change the value of TWD." > + * (MAX77714 datasheet) > + */ > + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL3, > + MAX77714_WDTC, 1); > + if (err) > + return err; > + > + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, > + MAX77714_TWD_MASK, new_twd); > + if (err) > + return err; > + > + wd_dev->timeout = new_timeout; > + > + dev_dbg(wdt->dev, "New timeout = %u s (WDT = 0x%x)", new_timeout, new_twd); > + > + return 0; > +} > + > +static const struct watchdog_info max77714_wdt_info = { > + .identity = "max77714-watchdog", > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, > +}; > + > +static const struct watchdog_ops max77714_wdt_ops = { > + .start = max77714_wdt_start, > + .stop = max77714_wdt_stop, > + .ping = max77714_wdt_ping, > + .set_timeout = max77714_wdt_set_timeout, > +}; > + > +static int max77714_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct max77714_wdt *wdt; > + struct watchdog_device *wd_dev; > + unsigned int regval; > + int err; > + > + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); > + if (!wdt) > + return -ENOMEM; > + > + wdt->dev = dev; > + > + wd_dev = &wdt->wd_dev; > + wd_dev->info = &max77714_wdt_info; > + wd_dev->ops = &max77714_wdt_ops; > + wd_dev->min_timeout = 2; > + wd_dev->max_timeout = 128; > + > + platform_set_drvdata(pdev, wdt); > + watchdog_set_drvdata(wd_dev, wdt); > + > + wdt->rmap = dev_get_regmap(dev->parent, NULL); > + if (!wdt->rmap) > + return dev_err_probe(wdt->dev, -ENODEV, "Failed to get parent regmap\n"); > + > + /* WD_RST_WK: if 1 wdog restarts; if 0 wdog shuts down */ > + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG2_ONOFF, > + MAX77714_WD_RST_WK, MAX77714_WD_RST_WK); > + if (err) > + return dev_err_probe(wdt->dev, err, "Error updating CNFG2_ONOFF\n"); > + > + err = regmap_read(wdt->rmap, MAX77714_CNFG_GLBL2, ®val); > + if (err) > + return dev_err_probe(wdt->dev, err, "Error reading CNFG_GLBL2\n"); > + > + /* enable watchdog | enable auto-clear in sleep state */ > + regval |= (MAX77714_WDTEN | MAX77714_WDTSLPC); > + > + err = regmap_write(wdt->rmap, MAX77714_CNFG_GLBL2, regval); > + if (err) > + return dev_err_probe(wdt->dev, err, "Error writing CNFG_GLBL2\n"); > + > + wd_dev->timeout = max77714_margin_value[regval & MAX77714_TWD_MASK]; > + > + dev_dbg(wdt->dev, "Timeout = %u s (WDT = 0x%x)", > + wd_dev->timeout, regval & MAX77714_TWD_MASK); > + > + set_bit(WDOG_HW_RUNNING, &wd_dev->status); > + > + watchdog_stop_on_unregister(wd_dev); > + > + err = devm_watchdog_register_device(dev, wd_dev); > + if (err) > + return dev_err_probe(dev, err, "Cannot register watchdog device\n"); > + > + dev_info(dev, "registered as /dev/watchdog%d\n", wd_dev->id); > + > + return 0; > +} > + > +static const struct platform_device_id max77714_wdt_platform_id[] = { > + { .name = "max77714-watchdog", }, > + { }, > +}; > +MODULE_DEVICE_TABLE(platform, max77714_wdt_platform_id); > + > +static struct platform_driver max77714_wdt_driver = { > + .driver = { > + .name = "max77714-watchdog", > + }, > + .probe = max77714_wdt_probe, > + .id_table = max77714_wdt_platform_id, > +}; > + > +module_platform_driver(max77714_wdt_driver); > + > +MODULE_DESCRIPTION("MAX77714 watchdog timer driver"); > +MODULE_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>"); > +MODULE_LICENSE("GPL v2"); >
diff --git a/MAINTAINERS b/MAINTAINERS index abd9de8a9d99..71c3d8513ba0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11391,6 +11391,7 @@ M: Luca Ceresoli <luca@lucaceresoli.net> S: Maintained F: Documentation/devicetree/bindings/mfd/maxim,max77714.yaml F: drivers/mfd/max77714.c +F: drivers/watchdog/max77714_wdt.c F: include/linux/mfd/max77714.h MAXIM MAX77802 PMIC REGULATOR DEVICE DRIVER diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index a24385099a91..b9b575acd690 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -699,6 +699,15 @@ config MAX77620_WATCHDOG MAX77620 chips. To compile this driver as a module, choose M here: the module will be called max77620_wdt. +config MAX77714_WATCHDOG + tristate "Maxim MAX77714 Watchdog Timer" + depends on MFD_MAX77714 || COMPILE_TEST + help + This is the driver for watchdog timer in the MAX77714 PMIC. + Say 'Y' here to enable the watchdog timer support for MAX77714 + chips. To compile this driver as a module, choose M here: the + module will be called max77714_wdt. + config IMX2_WDT tristate "IMX2+ Watchdog" depends on ARCH_MXC || ARCH_LAYERSCAPE || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 1bd2d6f37c53..268a942311a0 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -215,6 +215,7 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o obj-$(CONFIG_MAX77620_WATCHDOG) += max77620_wdt.o +obj-$(CONFIG_MAX77714_WATCHDOG) += max77714_wdt.o obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o diff --git a/drivers/watchdog/max77714_wdt.c b/drivers/watchdog/max77714_wdt.c new file mode 100644 index 000000000000..cce6c13d76eb --- /dev/null +++ b/drivers/watchdog/max77714_wdt.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Maxim MAX77714 Watchdog Driver + * + * Copyright (C) 2021 Luca Ceresoli + * Author: Luca Ceresoli <luca@lucaceresoli.net> + */ + +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/mfd/max77714.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/watchdog.h> + +struct max77714_wdt { + struct device *dev; + struct regmap *rmap; + struct watchdog_device wd_dev; +}; + +/* Timeout in seconds, indexed by TWD bits of CNFG_GLBL2 register */ +static const unsigned int max77714_margin_value[] = { 2, 16, 64, 128 }; + +static int max77714_wdt_start(struct watchdog_device *wd_dev) +{ + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); + + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, + MAX77714_WDTEN, MAX77714_WDTEN); +} + +static int max77714_wdt_stop(struct watchdog_device *wd_dev) +{ + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); + + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, + MAX77714_WDTEN, 0); +} + +static int max77714_wdt_ping(struct watchdog_device *wd_dev) +{ + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); + + return regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL3, + MAX77714_WDTC, 1); +} + +static int max77714_wdt_set_timeout(struct watchdog_device *wd_dev, + unsigned int timeout) +{ + struct max77714_wdt *wdt = watchdog_get_drvdata(wd_dev); + unsigned int new_timeout, new_twd; + int err; + + for (new_twd = 0; new_twd < ARRAY_SIZE(max77714_margin_value) - 1; new_twd++) + if (timeout <= max77714_margin_value[new_twd]) + break; + + /* new_wdt is not out of bounds here due to the "- 1" in the for loop */ + new_timeout = max77714_margin_value[new_twd]; + + /* + * "If the value of TWD needs to be changed, clear the system + * watchdog timer first [...], then change the value of TWD." + * (MAX77714 datasheet) + */ + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL3, + MAX77714_WDTC, 1); + if (err) + return err; + + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG_GLBL2, + MAX77714_TWD_MASK, new_twd); + if (err) + return err; + + wd_dev->timeout = new_timeout; + + dev_dbg(wdt->dev, "New timeout = %u s (WDT = 0x%x)", new_timeout, new_twd); + + return 0; +} + +static const struct watchdog_info max77714_wdt_info = { + .identity = "max77714-watchdog", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops max77714_wdt_ops = { + .start = max77714_wdt_start, + .stop = max77714_wdt_stop, + .ping = max77714_wdt_ping, + .set_timeout = max77714_wdt_set_timeout, +}; + +static int max77714_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct max77714_wdt *wdt; + struct watchdog_device *wd_dev; + unsigned int regval; + int err; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->dev = dev; + + wd_dev = &wdt->wd_dev; + wd_dev->info = &max77714_wdt_info; + wd_dev->ops = &max77714_wdt_ops; + wd_dev->min_timeout = 2; + wd_dev->max_timeout = 128; + + platform_set_drvdata(pdev, wdt); + watchdog_set_drvdata(wd_dev, wdt); + + wdt->rmap = dev_get_regmap(dev->parent, NULL); + if (!wdt->rmap) + return dev_err_probe(wdt->dev, -ENODEV, "Failed to get parent regmap\n"); + + /* WD_RST_WK: if 1 wdog restarts; if 0 wdog shuts down */ + err = regmap_update_bits(wdt->rmap, MAX77714_CNFG2_ONOFF, + MAX77714_WD_RST_WK, MAX77714_WD_RST_WK); + if (err) + return dev_err_probe(wdt->dev, err, "Error updating CNFG2_ONOFF\n"); + + err = regmap_read(wdt->rmap, MAX77714_CNFG_GLBL2, ®val); + if (err) + return dev_err_probe(wdt->dev, err, "Error reading CNFG_GLBL2\n"); + + /* enable watchdog | enable auto-clear in sleep state */ + regval |= (MAX77714_WDTEN | MAX77714_WDTSLPC); + + err = regmap_write(wdt->rmap, MAX77714_CNFG_GLBL2, regval); + if (err) + return dev_err_probe(wdt->dev, err, "Error writing CNFG_GLBL2\n"); + + wd_dev->timeout = max77714_margin_value[regval & MAX77714_TWD_MASK]; + + dev_dbg(wdt->dev, "Timeout = %u s (WDT = 0x%x)", + wd_dev->timeout, regval & MAX77714_TWD_MASK); + + set_bit(WDOG_HW_RUNNING, &wd_dev->status); + + watchdog_stop_on_unregister(wd_dev); + + err = devm_watchdog_register_device(dev, wd_dev); + if (err) + return dev_err_probe(dev, err, "Cannot register watchdog device\n"); + + dev_info(dev, "registered as /dev/watchdog%d\n", wd_dev->id); + + return 0; +} + +static const struct platform_device_id max77714_wdt_platform_id[] = { + { .name = "max77714-watchdog", }, + { }, +}; +MODULE_DEVICE_TABLE(platform, max77714_wdt_platform_id); + +static struct platform_driver max77714_wdt_driver = { + .driver = { + .name = "max77714-watchdog", + }, + .probe = max77714_wdt_probe, + .id_table = max77714_wdt_platform_id, +}; + +module_platform_driver(max77714_wdt_driver); + +MODULE_DESCRIPTION("MAX77714 watchdog timer driver"); +MODULE_AUTHOR("Luca Ceresoli <luca@lucaceresoli.net>"); +MODULE_LICENSE("GPL v2");
Add a simple driver to support the watchdog embedded in the Maxim MAX77714 PMIC. Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net> --- Changes in v2: - fix Kconfig help indentation (Randy Dunlap) - make max77714_margin_value static const (Guenter Roeck) - fix platform module instantiation --- MAINTAINERS | 1 + drivers/watchdog/Kconfig | 9 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/max77714_wdt.c | 179 ++++++++++++++++++++++++++++++++ 4 files changed, 190 insertions(+) create mode 100644 drivers/watchdog/max77714_wdt.c