Message ID | 1418834727-1602-7-git-send-email-lee.jones@linaro.org |
---|---|
State | Superseded |
Headers | show |
On Wed, Dec 17, 2014 at 04:45:25PM +0000, Lee Jones wrote: > Signed-off-by: David Paris <david.paris@st.com> > Signed-off-by: Lee Jones <lee.jones@linaro.org> Hi Lee and David, I still have a couple of comments below. Sorry I didn't catch those earlier. Thanks, Guenter > --- > drivers/watchdog/Kconfig | 13 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/st_wdt.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 337 insertions(+) > create mode 100644 drivers/watchdog/st_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index f57312f..5a538af 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -432,6 +432,19 @@ config SIRFSOC_WATCHDOG > Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When > the watchdog triggers the system will be reset. > > +config ST_WATCHDOG > + tristate "STMicroelectronics LPC Watchdog" > + depends on ARCH_STI > + depends on OF > + select WATCHDOG_CORE > + select MFD_ST_LPC > + help > + Say Y here to include STMicroelectronics Low Power Controller > + (LPC) based Watchdog timer support. > + > + To compile this driver as a module, choose M here: the > + module will be called st_wdt. > + > config TEGRA_WATCHDOG > tristate "Tegra watchdog" > depends on ARCH_TEGRA || COMPILE_TEST > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 468c320..eb19937 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -57,6 +57,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o > obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o > obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o > obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o > +obj-$(CONFIG_ST_WATCHDOG) += st_wdt.o > obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o > obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o > > diff --git a/drivers/watchdog/st_wdt.c b/drivers/watchdog/st_wdt.c > new file mode 100644 > index 0000000..cf3a4f7 > --- /dev/null > +++ b/drivers/watchdog/st_wdt.c > @@ -0,0 +1,323 @@ > +/* > + * st-wdt.c - ST's LPC Watchdog > + * > + * Copyright (C) 2014 STMicroelectronics -- All Rights Reserved > + * > + * Author: David Paris <david.paris@st.com> for STMicroelectronics > + * Lee Jones <lee.jones@linaro.org> for STMicroelectronics > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of the GNU General Public Licence > + * as published by the Free Software Foundation; either version > + * 2 of the Licence, or (at your option) any later version. > + */ > + > +#include <linux/clk.h> > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > +#include <linux/mfd/syscon.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_platform.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/watchdog.h> > + > +#include <dt-bindings/mfd/st-lpc.h> > + > +/* Low Power Alarm */ > +#define LPC_LPA_LSB_OFF 0x410 > +#define LPC_LPA_START_OFF 0x418 > + > +/* LPC as WDT */ > +#define LPC_WDT_OFF 0x510 > + > +static struct watchdog_device st_wdog_dev; > + > +struct st_wdog_syscfg { > + struct regmap *regmap; > + unsigned int reset_type_reg; > + unsigned int reset_type_mask; > + unsigned int enable_reg; > + unsigned int enable_mask; > +}; > + > +struct st_wdog { > + void __iomem *base; > + struct device *dev; > + struct st_wdog_syscfg *syscfg; > + struct clk *clk; > + unsigned long clkrate; > + bool warm_reset; > +}; > + > +static struct st_wdog_syscfg stid127_syscfg = { > + .reset_type_reg = 0x004, > + .reset_type_mask = BIT(2), > + .enable_reg = 0x000, > + .enable_mask = BIT(2), > +}; > + > +static struct st_wdog_syscfg stih415_syscfg = { > + .reset_type_reg = 0x0B8, > + .reset_type_mask = BIT(6), > + .enable_reg = 0x0B4, > + .enable_mask = BIT(7), > +}; > + > +static struct st_wdog_syscfg stih416_syscfg = { > + .reset_type_reg = 0x88C, > + .reset_type_mask = BIT(6), > + .enable_reg = 0x888, > + .enable_mask = BIT(7), > +}; > + > +static struct st_wdog_syscfg stih407_syscfg = { > + .enable_reg = 0x204, > + .enable_mask = BIT(19), > +}; > + > +static struct of_device_id st_wdog_match[] = { > + { > + .compatible = "st,stih407-lpc", > + .data = (void *)&stih407_syscfg, Nitpick: typecast to and from void * is not necessary. > + }, > + { > + .compatible = "st,stih416-lpc", > + .data = (void *)&stih416_syscfg, > + }, > + { > + .compatible = "st,stih415-lpc", > + .data = (void *)&stih415_syscfg, > + }, > + { > + .compatible = "st,stid127-lpc", > + .data = (void *)&stid127_syscfg, > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, st_wdog_match); > + > +static void st_wdog_setup(struct st_wdog *st_wdog, bool enable) > +{ > + /* Type of watchdog reset - 0: Cold 1: Warm */ > + if (st_wdog->syscfg->reset_type_reg) > + regmap_update_bits(st_wdog->syscfg->regmap, > + st_wdog->syscfg->reset_type_reg, > + st_wdog->syscfg->reset_type_mask, > + st_wdog->warm_reset); > + > + /* Mask/unmask watchdog reset */ > + regmap_update_bits(st_wdog->syscfg->regmap, > + st_wdog->syscfg->enable_reg, > + st_wdog->syscfg->enable_mask, > + enable ? 0 : st_wdog->syscfg->enable_mask); > +} > + > +static void st_wdog_load_timer(struct st_wdog *st_wdog, unsigned int timeout) > +{ > + unsigned long clkrate = st_wdog->clkrate; > + > + writel_relaxed(timeout * clkrate, st_wdog->base + LPC_LPA_LSB_OFF); > + writel_relaxed(1, st_wdog->base + LPC_LPA_START_OFF); > +} > + > +static int st_wdog_start(struct watchdog_device *wdd) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); > + > + writel_relaxed(1, st_wdog->base + LPC_WDT_OFF); > + > + return 0; > +} > + > +static int st_wdog_stop(struct watchdog_device *wdd) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); > + > + writel_relaxed(0, st_wdog->base + LPC_WDT_OFF); > + > + return 0; > +} > + > +static int st_wdog_set_timeout(struct watchdog_device *wdd, > + unsigned int timeout) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); > + > + wdd->timeout = timeout; > + st_wdog_load_timer(st_wdog, timeout); > + > + return 0; > +} > + > +static int st_wdog_keepalive(struct watchdog_device *wdd) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); > + > + st_wdog_load_timer(st_wdog, wdd->timeout); > + > + return 0; > +} > + > +static const struct watchdog_info st_wdog_info = { > + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, > + .identity = "ST LPC WDT", > +}; > + > +static const struct watchdog_ops st_wdog_ops = { > + .owner = THIS_MODULE, > + .start = st_wdog_start, > + .stop = st_wdog_stop, > + .ping = st_wdog_keepalive, > + .set_timeout = st_wdog_set_timeout, > +}; > + > +static struct watchdog_device st_wdog_dev = { > + .info = &st_wdog_info, > + .ops = &st_wdog_ops, > +}; > + > +static int st_wdog_probe(struct platform_device *pdev) > +{ > + const struct of_device_id *match; > + struct device_node *np = pdev->dev.of_node; > + struct st_wdog *st_wdog; > + struct regmap *regmap; > + struct resource *res; > + struct clk *clk; > + void __iomem *base; > + uint32_t mode; > + int ret; > + > + ret = of_property_read_u32(np, "st,lpc-mode", &mode); > + if (ret) { > + dev_err(&pdev->dev, "An LPC mode must be provided\n"); > + return -EINVAL; > + } > + > + /* LPC can either run in RTC or WDT mode */ > + if (mode != ST_LPC_MODE_WDT) > + return -ENODEV; > + > + st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL); > + if (!st_wdog) > + return -ENOMEM; > + > + match = of_match_device(st_wdog_match, &pdev->dev); > + if (!match) { > + dev_err(&pdev->dev, "Couldn't match device\n"); > + return -ENODEV; > + } > + st_wdog->syscfg = (struct st_wdog_syscfg *)match->data; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(base)) { > + dev_err(&pdev->dev, "Failed to ioremap base\n"); > + return PTR_ERR(base); > + } > + > + regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); > + if (IS_ERR(regmap)) { > + dev_err(&pdev->dev, "No syscfg phandle specified\n"); > + return PTR_ERR(regmap); > + } > + > + clk = clk_get(&pdev->dev, NULL); > + if (IS_ERR(clk)) { > + dev_err(&pdev->dev, "Unable to request clock\n"); > + return PTR_ERR(clk); > + } > + clk_prepare_enable(st_wdog->clk); How does this work ? st_wdog->clk isn't set yet. > + > + st_wdog->dev = &pdev->dev; > + st_wdog->base = base; > + st_wdog->clk = clk; > + st_wdog->syscfg->regmap = regmap; > + st_wdog->warm_reset = of_property_read_bool(np, "st,warm_reset"); > + st_wdog->clkrate = clk_get_rate(st_wdog->clk); > + > + if (!st_wdog->clkrate) { > + dev_err(&pdev->dev, "Unable to fetch clock rate\n"); I think this is missing clk_disable_unprepare(); clk_put(); Same for the rest of the error path handling below. > + return -EINVAL; > + } > + st_wdog_dev.max_timeout = 0xFFFFFFFF / st_wdog->clkrate; > + > + watchdog_set_drvdata(&st_wdog_dev, st_wdog); > + watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT); > + > + /* Init Watchdog timeout with value in DT */ > + ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev); > + if (ret) { > + dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n"); > + return ret; > + } > + > + ret = watchdog_register_device(&st_wdog_dev); > + if (ret) { > + dev_err(&pdev->dev, "Unable to register watchdog\n"); > + clk_disable_unprepare(clk); > + return ret; > + } > + > + st_wdog_setup(st_wdog, true); > + > + dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s", > + st_wdog->warm_reset ? "warm" : "cold"); > + > + return ret; > +} > + > +static int st_wdog_remove(struct platform_device *pdev) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); > + > + st_wdog_setup(st_wdog, false); > + watchdog_unregister_device(&st_wdog_dev); > + clk_disable_unprepare(st_wdog->clk); > + clk_put() ? > + return 0; > +} > + > +#ifdef CONFIG_PM I think this needs to be CONFIG_PM_SLEEP. Another option might be to drop the #ifdef entirely and use __maybe_unused instead. > +static int st_wdog_suspend(struct device *dev) > +{ > + if (watchdog_active(&st_wdog_dev)) > + st_wdog_stop(&st_wdog_dev); > + > + return 0; > +} > + > +static int st_wdog_resume(struct device *dev) > +{ > + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); > + > + if (watchdog_active(&st_wdog_dev)) { > + st_wdog_load_timer(st_wdog, st_wdog_dev.timeout); > + st_wdog_start(&st_wdog_dev); > + } > + > + return 0; > +} > +#endif > + > +static SIMPLE_DEV_PM_OPS(st_wdog_pm_ops, > + st_wdog_suspend, > + st_wdog_resume); > + > +static struct platform_driver st_wdog_driver = { > + .driver = { > + .name = "st-lpc-wdt", > + .pm = &st_wdog_pm_ops, > + .of_match_table = st_wdog_match, > + }, > + .probe = st_wdog_probe, > + .remove = st_wdog_remove, > +}; > +module_platform_driver(st_wdog_driver); > + > +MODULE_AUTHOR("David Paris <david.paris@st.com>"); > +MODULE_DESCRIPTION("ST LPC Watchdog Driver"); > +MODULE_LICENSE("GPL v2"); > -- > 1.9.1 >
On Wed, 17 Dec 2014, Guenter Roeck wrote: > On Wed, Dec 17, 2014 at 04:45:25PM +0000, Lee Jones wrote: > > Signed-off-by: David Paris <david.paris@st.com> > > Signed-off-by: Lee Jones <lee.jones@linaro.org> > > Hi Lee and David, > > I still have a couple of comments below. Sorry I didn't catch those earlier. > > Thanks, > Guenter > > > --- > > drivers/watchdog/Kconfig | 13 ++ > > drivers/watchdog/Makefile | 1 + > > drivers/watchdog/st_wdt.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 337 insertions(+) > > create mode 100644 drivers/watchdog/st_wdt.c Chopping all the crud. [...] > > +static struct of_device_id st_wdog_match[] = { > > + { > > + .compatible = "st,stih407-lpc", > > + .data = (void *)&stih407_syscfg, > > Nitpick: typecast to and from void * is not necessary. Actually that's not true, but it is superfluous in this case. I will fix-up. [...] > > +static int st_wdog_probe(struct platform_device *pdev) > > +{ > > + const struct of_device_id *match; > > + struct device_node *np = pdev->dev.of_node; > > + struct st_wdog *st_wdog; > > + struct regmap *regmap; > > + struct resource *res; > > + struct clk *clk; > > + void __iomem *base; > > + uint32_t mode; > > + int ret; [...] > > + clk = clk_get(&pdev->dev, NULL); > > + if (IS_ERR(clk)) { > > + dev_err(&pdev->dev, "Unable to request clock\n"); > > + return PTR_ERR(clk); > > + } > > + clk_prepare_enable(st_wdog->clk); > > How does this work ? st_wdog->clk isn't set yet. Great spot. That should be 'clk'. It works because the LPC clk is already on. > > + > > + st_wdog->dev = &pdev->dev; > > + st_wdog->base = base; > > + st_wdog->clk = clk; > > + st_wdog->syscfg->regmap = regmap; > > + st_wdog->warm_reset = of_property_read_bool(np, "st,warm_reset"); > > + st_wdog->clkrate = clk_get_rate(st_wdog->clk); > > + > > + if (!st_wdog->clkrate) { > > + dev_err(&pdev->dev, "Unable to fetch clock rate\n"); > > I think this is missing > clk_disable_unprepare(); > clk_put(); > > Same for the rest of the error path handling below. Actually instead of clk_put we should be using s/clk_get/devm_clk_get/. You're right about the error paths. I will enforce a better one. Thanks. [...] > > +#ifdef CONFIG_PM > > I think this needs to be CONFIG_PM_SLEEP. > Another option might be to drop the #ifdef entirely and use > __maybe_unused instead. Hmmm... what version is this? [2 mins pass] Oh rubbish. I've been a silly boy! [spoiler alert: take a look at the end of the RTC driver patch] Will be fixed in v3. [...]
Hi Lee, On Wed, 17 Dec 2014, Lee Jones wrote: > Signed-off-by: David Paris <david.paris@st.com> > Signed-off-by: Lee Jones <lee.jones@linaro.org> > --- > drivers/watchdog/Kconfig | 13 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/st_wdt.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++ You don't have a patch which adds the new files created in this series into the STI section of the MAINTAINERS file? regards, Peter.
On Thu, 18 Dec 2014, Peter Griffin wrote: > Hi Lee, > > On Wed, 17 Dec 2014, Lee Jones wrote: > > > Signed-off-by: David Paris <david.paris@st.com> > > Signed-off-by: Lee Jones <lee.jones@linaro.org> > > --- > > drivers/watchdog/Kconfig | 13 ++ > > drivers/watchdog/Makefile | 1 + > > drivers/watchdog/st_wdt.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++ > > You don't have a patch which adds the new files created in this series into > the STI section of the MAINTAINERS file? Very true. I will supply one, thanks.
On Thu, Dec 18, 2014 at 08:26:52AM +0000, Lee Jones wrote: > On Wed, 17 Dec 2014, Guenter Roeck wrote: > > On Wed, Dec 17, 2014 at 04:45:25PM +0000, Lee Jones wrote: > > > Signed-off-by: David Paris <david.paris@st.com> > > > Signed-off-by: Lee Jones <lee.jones@linaro.org> > > > > Hi Lee and David, > > > > I still have a couple of comments below. Sorry I didn't catch those earlier. > > > > Thanks, > > Guenter > > > > > --- > > > drivers/watchdog/Kconfig | 13 ++ > > > drivers/watchdog/Makefile | 1 + > > > drivers/watchdog/st_wdt.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++ > > > 3 files changed, 337 insertions(+) > > > create mode 100644 drivers/watchdog/st_wdt.c > > Chopping all the crud. > > [...] > > > > +static struct of_device_id st_wdog_match[] = { > > > + { > > > + .compatible = "st,stih407-lpc", > > > + .data = (void *)&stih407_syscfg, > > > > Nitpick: typecast to and from void * is not necessary. > > Actually that's not true, but it is superfluous in this case. > Point taken. Would you agree to a more detailed "typecasting a pointer to and from void * is not necessary" ? Guenter
On Thu, 18 Dec 2014, Guenter Roeck wrote: > On Thu, Dec 18, 2014 at 08:26:52AM +0000, Lee Jones wrote: > > On Wed, 17 Dec 2014, Guenter Roeck wrote: > > > On Wed, Dec 17, 2014 at 04:45:25PM +0000, Lee Jones wrote: > > > > Signed-off-by: David Paris <david.paris@st.com> > > > > Signed-off-by: Lee Jones <lee.jones@linaro.org> > > > > > > Hi Lee and David, > > > > > > I still have a couple of comments below. Sorry I didn't catch those earlier. > > > > > > Thanks, > > > Guenter > > > > > > > --- > > > > drivers/watchdog/Kconfig | 13 ++ > > > > drivers/watchdog/Makefile | 1 + > > > > drivers/watchdog/st_wdt.c | 323 ++++++++++++++++++++++++++++++++++++++++++++++ > > > > 3 files changed, 337 insertions(+) > > > > create mode 100644 drivers/watchdog/st_wdt.c > > > > Chopping all the crud. > > > > [...] > > > > > > +static struct of_device_id st_wdog_match[] = { > > > > + { > > > > + .compatible = "st,stih407-lpc", > > > > + .data = (void *)&stih407_syscfg, > > > > > > Nitpick: typecast to and from void * is not necessary. > > > > Actually that's not true, but it is superfluous in this case. > > > Point taken. Would you agree to a more detailed "typecasting a pointer > to and from void * is not necessary" ? Sure, why not? ;)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index f57312f..5a538af 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -432,6 +432,19 @@ config SIRFSOC_WATCHDOG Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When the watchdog triggers the system will be reset. +config ST_WATCHDOG + tristate "STMicroelectronics LPC Watchdog" + depends on ARCH_STI + depends on OF + select WATCHDOG_CORE + select MFD_ST_LPC + help + Say Y here to include STMicroelectronics Low Power Controller + (LPC) based Watchdog timer support. + + To compile this driver as a module, choose M here: the + module will be called st_wdt. + config TEGRA_WATCHDOG tristate "Tegra watchdog" depends on ARCH_TEGRA || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 468c320..eb19937 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -57,6 +57,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o +obj-$(CONFIG_ST_WATCHDOG) += st_wdt.o obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o diff --git a/drivers/watchdog/st_wdt.c b/drivers/watchdog/st_wdt.c new file mode 100644 index 0000000..cf3a4f7 --- /dev/null +++ b/drivers/watchdog/st_wdt.c @@ -0,0 +1,323 @@ +/* + * st-wdt.c - ST's LPC Watchdog + * + * Copyright (C) 2014 STMicroelectronics -- All Rights Reserved + * + * Author: David Paris <david.paris@st.com> for STMicroelectronics + * Lee Jones <lee.jones@linaro.org> for STMicroelectronics + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include <linux/clk.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/watchdog.h> + +#include <dt-bindings/mfd/st-lpc.h> + +/* Low Power Alarm */ +#define LPC_LPA_LSB_OFF 0x410 +#define LPC_LPA_START_OFF 0x418 + +/* LPC as WDT */ +#define LPC_WDT_OFF 0x510 + +static struct watchdog_device st_wdog_dev; + +struct st_wdog_syscfg { + struct regmap *regmap; + unsigned int reset_type_reg; + unsigned int reset_type_mask; + unsigned int enable_reg; + unsigned int enable_mask; +}; + +struct st_wdog { + void __iomem *base; + struct device *dev; + struct st_wdog_syscfg *syscfg; + struct clk *clk; + unsigned long clkrate; + bool warm_reset; +}; + +static struct st_wdog_syscfg stid127_syscfg = { + .reset_type_reg = 0x004, + .reset_type_mask = BIT(2), + .enable_reg = 0x000, + .enable_mask = BIT(2), +}; + +static struct st_wdog_syscfg stih415_syscfg = { + .reset_type_reg = 0x0B8, + .reset_type_mask = BIT(6), + .enable_reg = 0x0B4, + .enable_mask = BIT(7), +}; + +static struct st_wdog_syscfg stih416_syscfg = { + .reset_type_reg = 0x88C, + .reset_type_mask = BIT(6), + .enable_reg = 0x888, + .enable_mask = BIT(7), +}; + +static struct st_wdog_syscfg stih407_syscfg = { + .enable_reg = 0x204, + .enable_mask = BIT(19), +}; + +static struct of_device_id st_wdog_match[] = { + { + .compatible = "st,stih407-lpc", + .data = (void *)&stih407_syscfg, + }, + { + .compatible = "st,stih416-lpc", + .data = (void *)&stih416_syscfg, + }, + { + .compatible = "st,stih415-lpc", + .data = (void *)&stih415_syscfg, + }, + { + .compatible = "st,stid127-lpc", + .data = (void *)&stid127_syscfg, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, st_wdog_match); + +static void st_wdog_setup(struct st_wdog *st_wdog, bool enable) +{ + /* Type of watchdog reset - 0: Cold 1: Warm */ + if (st_wdog->syscfg->reset_type_reg) + regmap_update_bits(st_wdog->syscfg->regmap, + st_wdog->syscfg->reset_type_reg, + st_wdog->syscfg->reset_type_mask, + st_wdog->warm_reset); + + /* Mask/unmask watchdog reset */ + regmap_update_bits(st_wdog->syscfg->regmap, + st_wdog->syscfg->enable_reg, + st_wdog->syscfg->enable_mask, + enable ? 0 : st_wdog->syscfg->enable_mask); +} + +static void st_wdog_load_timer(struct st_wdog *st_wdog, unsigned int timeout) +{ + unsigned long clkrate = st_wdog->clkrate; + + writel_relaxed(timeout * clkrate, st_wdog->base + LPC_LPA_LSB_OFF); + writel_relaxed(1, st_wdog->base + LPC_LPA_START_OFF); +} + +static int st_wdog_start(struct watchdog_device *wdd) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); + + writel_relaxed(1, st_wdog->base + LPC_WDT_OFF); + + return 0; +} + +static int st_wdog_stop(struct watchdog_device *wdd) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); + + writel_relaxed(0, st_wdog->base + LPC_WDT_OFF); + + return 0; +} + +static int st_wdog_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); + + wdd->timeout = timeout; + st_wdog_load_timer(st_wdog, timeout); + + return 0; +} + +static int st_wdog_keepalive(struct watchdog_device *wdd) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); + + st_wdog_load_timer(st_wdog, wdd->timeout); + + return 0; +} + +static const struct watchdog_info st_wdog_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "ST LPC WDT", +}; + +static const struct watchdog_ops st_wdog_ops = { + .owner = THIS_MODULE, + .start = st_wdog_start, + .stop = st_wdog_stop, + .ping = st_wdog_keepalive, + .set_timeout = st_wdog_set_timeout, +}; + +static struct watchdog_device st_wdog_dev = { + .info = &st_wdog_info, + .ops = &st_wdog_ops, +}; + +static int st_wdog_probe(struct platform_device *pdev) +{ + const struct of_device_id *match; + struct device_node *np = pdev->dev.of_node; + struct st_wdog *st_wdog; + struct regmap *regmap; + struct resource *res; + struct clk *clk; + void __iomem *base; + uint32_t mode; + int ret; + + ret = of_property_read_u32(np, "st,lpc-mode", &mode); + if (ret) { + dev_err(&pdev->dev, "An LPC mode must be provided\n"); + return -EINVAL; + } + + /* LPC can either run in RTC or WDT mode */ + if (mode != ST_LPC_MODE_WDT) + return -ENODEV; + + st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL); + if (!st_wdog) + return -ENOMEM; + + match = of_match_device(st_wdog_match, &pdev->dev); + if (!match) { + dev_err(&pdev->dev, "Couldn't match device\n"); + return -ENODEV; + } + st_wdog->syscfg = (struct st_wdog_syscfg *)match->data; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) { + dev_err(&pdev->dev, "Failed to ioremap base\n"); + return PTR_ERR(base); + } + + regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); + if (IS_ERR(regmap)) { + dev_err(&pdev->dev, "No syscfg phandle specified\n"); + return PTR_ERR(regmap); + } + + clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) { + dev_err(&pdev->dev, "Unable to request clock\n"); + return PTR_ERR(clk); + } + clk_prepare_enable(st_wdog->clk); + + st_wdog->dev = &pdev->dev; + st_wdog->base = base; + st_wdog->clk = clk; + st_wdog->syscfg->regmap = regmap; + st_wdog->warm_reset = of_property_read_bool(np, "st,warm_reset"); + st_wdog->clkrate = clk_get_rate(st_wdog->clk); + + if (!st_wdog->clkrate) { + dev_err(&pdev->dev, "Unable to fetch clock rate\n"); + return -EINVAL; + } + st_wdog_dev.max_timeout = 0xFFFFFFFF / st_wdog->clkrate; + + watchdog_set_drvdata(&st_wdog_dev, st_wdog); + watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT); + + /* Init Watchdog timeout with value in DT */ + ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev); + if (ret) { + dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n"); + return ret; + } + + ret = watchdog_register_device(&st_wdog_dev); + if (ret) { + dev_err(&pdev->dev, "Unable to register watchdog\n"); + clk_disable_unprepare(clk); + return ret; + } + + st_wdog_setup(st_wdog, true); + + dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s", + st_wdog->warm_reset ? "warm" : "cold"); + + return ret; +} + +static int st_wdog_remove(struct platform_device *pdev) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); + + st_wdog_setup(st_wdog, false); + watchdog_unregister_device(&st_wdog_dev); + clk_disable_unprepare(st_wdog->clk); + + return 0; +} + +#ifdef CONFIG_PM +static int st_wdog_suspend(struct device *dev) +{ + if (watchdog_active(&st_wdog_dev)) + st_wdog_stop(&st_wdog_dev); + + return 0; +} + +static int st_wdog_resume(struct device *dev) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); + + if (watchdog_active(&st_wdog_dev)) { + st_wdog_load_timer(st_wdog, st_wdog_dev.timeout); + st_wdog_start(&st_wdog_dev); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(st_wdog_pm_ops, + st_wdog_suspend, + st_wdog_resume); + +static struct platform_driver st_wdog_driver = { + .driver = { + .name = "st-lpc-wdt", + .pm = &st_wdog_pm_ops, + .of_match_table = st_wdog_match, + }, + .probe = st_wdog_probe, + .remove = st_wdog_remove, +}; +module_platform_driver(st_wdog_driver); + +MODULE_AUTHOR("David Paris <david.paris@st.com>"); +MODULE_DESCRIPTION("ST LPC Watchdog Driver"); +MODULE_LICENSE("GPL v2");