| Message ID | cover.1601366711.git.matti.vaittinen@fi.rohmeurope.com |
|---|---|
| Headers | show |
| Series | Support ROHM BD9576MUF and BD9573MUF PMICs | expand |
On Tue, Sep 29, 2020 at 11:17:07AM +0300, Matti Vaittinen wrote: > Add Watchdog support for ROHM BD9576MUF and BD9573MUF PMICs which are > mainly used to power the R-Car series processors. The watchdog is > pinged using a GPIO and enabled using another GPIO. Additionally > watchdog time-out can be configured to HW prior starting the watchdog. > Watchdog timeout can be configured to detect only delayed ping or in > a window mode where also too fast pings are detected. > > Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > > Changes from v2: > - Replace bindings hw_margin_ms and rohm,hw-margin-min-ms with > rohm,hw-timeout-ms > > drivers/watchdog/Kconfig | 13 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/bd9576_wdt.c | 290 ++++++++++++++++++++++++++++++++++ > 3 files changed, 304 insertions(+) > create mode 100644 drivers/watchdog/bd9576_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index ab7aad5a1e69..d042a517a946 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -172,6 +172,19 @@ config BD70528_WATCHDOG > Alternatively say M to compile the driver as a module, > which will be called bd70528_wdt. > > +config BD957XMUF_WATCHDOG > + tristate "ROHM BD9576MUF and BD9573MUF PMIC Watchdog" > + depends on MFD_ROHM_BD957XMUF > + select WATCHDOG_CORE > + help > + Support for the watchdog in the ROHM BD9576 and BD9573 PMICs. > + These PMIC ICs contain watchdog block which can be configured > + to toggle reset line if SoC fails to ping watchdog via GPIO. > + > + Say Y here to include support for the ROHM BD9576 or BD9573 > + watchdog. Alternatively say M to compile the driver as a module, > + which will be called bd9576_wdt. > + > config DA9052_WATCHDOG > tristate "Dialog DA9052 Watchdog" > depends on PMIC_DA9052 || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 97bed1d3d97c..14d75f98e3df 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -208,6 +208,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o > > # Architecture Independent > obj-$(CONFIG_BD70528_WATCHDOG) += bd70528_wdt.o > +obj-$(CONFIG_BD957XMUF_WATCHDOG) += bd9576_wdt.o > obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o > obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o > obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o > diff --git a/drivers/watchdog/bd9576_wdt.c b/drivers/watchdog/bd9576_wdt.c > new file mode 100644 > index 000000000000..afef19ce01be > --- /dev/null > +++ b/drivers/watchdog/bd9576_wdt.c > @@ -0,0 +1,290 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Copyright (C) 2020 ROHM Semiconductors > + * > + * ROHM BD9576MUF and BD9573MUF Watchdog driver > + */ > + > +#include <linux/err.h> > +#include <linux/gpio/consumer.h> > +#include <linux/mfd/rohm-bd957x.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/watchdog.h> > + > +static bool nowayout; > +module_param(nowayout, bool, 0); > +MODULE_PARM_DESC(nowayout, > + "Watchdog cannot be stopped once started (default=\"false\")"); > + > +#define HW_MARGIN_MIN 2 > +#define HW_MARGIN_MAX 4416 > +#define BD957X_WDT_DEFAULT_MARGIN 4416 > + > +struct bd9576_wdt_priv { > + struct gpio_desc *gpiod_ping; > + struct gpio_desc *gpiod_en; > + struct device *dev; > + struct regmap *regmap; > + bool always_running; > + struct watchdog_device wdd; > +}; > + > +static void bd9576_wdt_disable(struct bd9576_wdt_priv *priv) > +{ > + gpiod_set_value_cansleep(priv->gpiod_en, 0); > +} > + > +static int bd9576_wdt_ping(struct watchdog_device *wdd) > +{ > + struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd); > + > + /* Pulse */ > + gpiod_set_value_cansleep(priv->gpiod_ping, 1); > + gpiod_set_value_cansleep(priv->gpiod_ping, 0); > + > + return 0; > +} > + > +static int bd9576_wdt_start(struct watchdog_device *wdd) > +{ > + struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd); > + > + gpiod_set_value_cansleep(priv->gpiod_en, 1); > + > + return bd9576_wdt_ping(wdd); > +} > + > +static int bd9576_wdt_stop(struct watchdog_device *wdd) > +{ > + struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd); > + > + if (!priv->always_running) > + bd9576_wdt_disable(priv); > + else > + set_bit(WDOG_HW_RUNNING, &wdd->status); > + > + return 0; > +} > + > +static const struct watchdog_info bd957x_wdt_ident = { > + .options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING | > + WDIOF_SETTIMEOUT, > + .identity = "BD957x Watchdog", > +}; > + > +static const struct watchdog_ops bd957x_wdt_ops = { > + .owner = THIS_MODULE, > + .start = bd9576_wdt_start, > + .stop = bd9576_wdt_stop, > + .ping = bd9576_wdt_ping, > +}; > + > +/* Unit is hundreds of uS */ > +#define FASTNG_MIN 23 > + > +static int find_closest_fast(int target, int *sel, int *val) > +{ > + int i; > + int window = FASTNG_MIN; > + > + for (i = 0; i < 8 && window < target; i++) > + window <<= 1; > + > + *val = window; > + *sel = i; > + > + if (i == 8) > + return -EINVAL; > + > + return 0; > + > +} > + > +static int find_closest_slow_by_fast(int fast_val, int target, int *slowsel) > +{ > + int sel; > + static const int multipliers[] = {2, 3, 7, 15}; > + > + for (sel = 0; sel < ARRAY_SIZE(multipliers) && > + multipliers[sel] * fast_val < target; sel++) > + ; > + > + if (sel == ARRAY_SIZE(multipliers)) > + return -EINVAL; > + > + *slowsel = sel; > + > + return 0; > +} > + > +static int find_closest_slow(int target, int *slow_sel, int *fast_sel) > +{ > + static const int multipliers[] = {2, 3, 7, 15}; > + int i, j; > + int val = 0; > + int window = FASTNG_MIN; > + > + for (i = 0; i < 8; i++) { > + for (j = 0; j < ARRAY_SIZE(multipliers); j++) { > + int slow; > + > + slow = window * multipliers[j]; > + if (slow >= target && (!val || slow < val)) { > + val = slow; > + *fast_sel = i; > + *slow_sel = j; > + } > + } > + window <<= 1; > + } > + if (!val) > + return -EINVAL; > + > + return 0; > +} > + > +#define BD957X_WDG_TYPE_WINDOW BIT(5) > +#define BD957X_WDG_TYPE_SLOW 0 > +#define BD957X_WDG_TYPE_MASK BIT(5) > +#define BD957X_WDG_NG_RATIO_MASK 0x18 > +#define BD957X_WDG_FASTNG_MASK 0x7 > + > +static int bd957x_set_wdt_mode(struct bd9576_wdt_priv *priv, int hw_margin, > + int hw_margin_min) > +{ > + int ret, fastng, slowng, type, reg, mask; > + struct device *dev = priv->dev; > + > + /* convert to 100uS */ > + hw_margin *= 10; > + hw_margin_min *= 10; > + if (hw_margin_min) { > + int min; > + > + type = BD957X_WDG_TYPE_WINDOW; > + dev_dbg(dev, "Setting type WINDOW 0x%x\n", type); > + ret = find_closest_fast(hw_margin_min, &fastng, &min); > + if (ret) { > + dev_err(dev, "bad WDT window for fast timeout\n"); > + return ret; > + } > + > + ret = find_closest_slow_by_fast(min, hw_margin, &slowng); > + if (ret) { > + dev_err(dev, "bad WDT window\n"); > + return ret; > + } > + > + } else { > + type = BD957X_WDG_TYPE_SLOW; > + dev_dbg(dev, "Setting type SLOW 0x%x\n", type); > + ret = find_closest_slow(hw_margin, &slowng, &fastng); > + if (ret) { > + dev_err(dev, "bad WDT window\n"); > + return ret; > + } > + } > + > + slowng <<= ffs(BD957X_WDG_NG_RATIO_MASK) - 1; > + reg = type | slowng | fastng; > + mask = BD957X_WDG_TYPE_MASK | BD957X_WDG_NG_RATIO_MASK | > + BD957X_WDG_FASTNG_MASK; > + ret = regmap_update_bits(priv->regmap, BD957X_REG_WDT_CONF, > + mask, reg); > + > + return ret; > +} > + > +static int bd9576_wdt_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct device_node *np = dev->parent->of_node; > + struct bd9576_wdt_priv *priv; > + u32 hw_margin[2]; > + u32 hw_margin_max = BD957X_WDT_DEFAULT_MARGIN, hw_margin_min = 0; > + int ret; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + platform_set_drvdata(pdev, priv); > + > + priv->dev = dev; > + priv->regmap = dev_get_regmap(dev->parent, NULL); > + if (!priv->regmap) { > + dev_err(dev, "No regmap found\n"); > + return -ENODEV; > + } > + > + priv->gpiod_en = devm_gpiod_get_from_of_node(dev, dev->parent->of_node, > + "rohm,watchdog-enable-gpios", > + 0, GPIOD_OUT_LOW, > + "watchdog-enable"); > + if (IS_ERR(priv->gpiod_en)) > + return dev_err_probe(dev, PTR_ERR(priv->gpiod_en), > + "getting watchdog-enable GPIO failed\n"); > + > + priv->gpiod_ping = devm_gpiod_get_from_of_node(dev, dev->parent->of_node, > + "rohm,watchdog-ping-gpios", > + 0, GPIOD_OUT_LOW, > + "watchdog-ping"); > + if (IS_ERR(priv->gpiod_ping)) > + return dev_err_probe(dev, PTR_ERR(priv->gpiod_ping), > + "getting watchdog-ping GPIO failed\n"); > + > + ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-ms", > + &hw_margin[0], 1, 2); > + if (ret < 0 && ret != -EINVAL) > + return ret; > + > + if (ret == 1) > + hw_margin_max = hw_margin[0]; > + > + if (ret == 2) { > + hw_margin_max = hw_margin[1]; > + hw_margin_min = hw_margin[0]; > + } > + > + ret = bd957x_set_wdt_mode(priv, hw_margin_max, hw_margin_min); > + if (ret) > + return ret; > + > + priv->always_running = of_property_read_bool(np, "always-running"); > + > + watchdog_set_drvdata(&priv->wdd, priv); > + > + priv->wdd.info = &bd957x_wdt_ident; > + priv->wdd.ops = &bd957x_wdt_ops; > + priv->wdd.min_hw_heartbeat_ms = hw_margin_min; > + priv->wdd.max_hw_heartbeat_ms = hw_margin_max; > + priv->wdd.parent = dev; > + priv->wdd.timeout = (hw_margin_max / 2) * 1000; > + > + watchdog_init_timeout(&priv->wdd, 0, dev); > + watchdog_set_nowayout(&priv->wdd, nowayout); > + > + watchdog_stop_on_reboot(&priv->wdd); > + > + if (priv->always_running) > + bd9576_wdt_start(&priv->wdd); > + > + return devm_watchdog_register_device(dev, &priv->wdd); > +} > + > +static struct platform_driver bd9576_wdt_driver = { > + .driver = { > + .name = "bd9576-wdt", > + }, > + .probe = bd9576_wdt_probe, > +}; > + > +module_platform_driver(bd9576_wdt_driver); > + > +MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>"); > +MODULE_DESCRIPTION("ROHM BD9576/BD9573 Watchdog driver"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("platform:bd9576-wdt"); > -- > 2.21.0 > > > -- > Matti Vaittinen, Linux device drivers > ROHM Semiconductors, Finland SWDC > Kiviharjunlenkki 1E > 90220 OULU > FINLAND > > ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~ > Simon says - in Latin please. > ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~ > Thanks to Simon Glass for the translation =]