| Message ID | 1418642738-17407-7-git-send-email-lee.jones@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
Hi Lee,
1. During resume stage the st_wdog_setup should be called again to
reconfigure LPC RTC as watchdog.
2. For Suspend/resume API, is CONFIG_PM necessary, CONFIG_PM_SLEEP
is enough as no PM_RUNTIME in this driver ! This will results in a
compilation warning if CONFIG_PM_SLEEP is unset for PM_RUNTIME not.
David
On 12/15/2014 12:25 PM, 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 | 312 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 326 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..7e06f15
> --- /dev/null
> +++ b/drivers/watchdog/st_wdt.c
> @@ -0,0 +1,312 @@
> +/*
> + * 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>
> +
> +/* Low Power Alarm */
> +#define LPC_LPA_LSB_OFF 0x410
> +#define LPC_LPA_START_OFF 0x418
> +
> +/* LPC as WDT */
> +#define LPC_WDT_OFF 0x510
> +
> +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;
> + int 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 = clk_get_rate(st_wdog->clk);
> + unsigned int maxtimeout = 0xFFFFFFFF / clkrate;
> +
> + if (timeout > maxtimeout) {
> + dev_warn(st_wdog->dev,
> + "timer overrun detected at current freq (%luHz)\n"
> + "wdog timeout set for %ds instead of requested %uis",
> + clkrate, maxtimeout, timeout);
> + timeout = maxtimeout;
> + }
> + timeout *= clkrate;
> +
> + writel_relaxed(timeout, 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;
> + struct st_wdog *st_wdog;
> + struct regmap *regmap;
> + struct resource *res;
> + struct clk *clk;
> + void __iomem *base;
> + int ret;
> +
> + /* This is a single node MFD device. */
> + np = pdev->dev.of_node = pdev->dev.parent->of_node;
> +
> + 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");
> +
> + 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,
> + },
> + .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");
Hi Lee,
Something I didn't pointed out before, this driver is only supposed
to support LPC_0 for stih407. The enable mask is only coded for LPC_0.
Is it a wanted behavior ?
In our current implementation here in ST is that LPC_0 is for A9
Watchdog and LPC_1 for A9 global timer. This has been translated in the
driver by hardcoding enable mask of LPC watchdog to only support LPC_0.
But do we want to have a more generic driver to be applicable both for
LPC_0 and LPC_1 ?
David
On 12/15/2014 12:25 PM, 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 | 312 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 326 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..7e06f15
> --- /dev/null
> +++ b/drivers/watchdog/st_wdt.c
> @@ -0,0 +1,312 @@
> +/*
> + * 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>
> +
> +/* Low Power Alarm */
> +#define LPC_LPA_LSB_OFF 0x410
> +#define LPC_LPA_START_OFF 0x418
> +
> +/* LPC as WDT */
> +#define LPC_WDT_OFF 0x510
> +
> +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;
> + int 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 = clk_get_rate(st_wdog->clk);
> + unsigned int maxtimeout = 0xFFFFFFFF / clkrate;
> +
> + if (timeout > maxtimeout) {
> + dev_warn(st_wdog->dev,
> + "timer overrun detected at current freq (%luHz)\n"
> + "wdog timeout set for %ds instead of requested %uis",
> + clkrate, maxtimeout, timeout);
> + timeout = maxtimeout;
> + }
> + timeout *= clkrate;
> +
> + writel_relaxed(timeout, 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;
> + struct st_wdog *st_wdog;
> + struct regmap *regmap;
> + struct resource *res;
> + struct clk *clk;
> + void __iomem *base;
> + int ret;
> +
> + /* This is a single node MFD device. */
> + np = pdev->dev.of_node = pdev->dev.parent->of_node;
> +
> + 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");
> +
> + 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,
> + },
> + .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");
On 12/15/2014 03:25 AM, 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 | 312 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 326 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..7e06f15 > --- /dev/null > +++ b/drivers/watchdog/st_wdt.c > @@ -0,0 +1,312 @@ > +/* > + * 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> > + > +/* Low Power Alarm */ > +#define LPC_LPA_LSB_OFF 0x410 > +#define LPC_LPA_START_OFF 0x418 > + > +/* LPC as WDT */ > +#define LPC_WDT_OFF 0x510 > + > +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; > + int 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 = clk_get_rate(st_wdog->clk); > + unsigned int maxtimeout = 0xFFFFFFFF / clkrate; > + > + if (timeout > maxtimeout) { > + dev_warn(st_wdog->dev, > + "timer overrun detected at current freq (%luHz)\n" > + "wdog timeout set for %ds instead of requested %uis", > + clkrate, maxtimeout, timeout); This warning will be repeated each time the watchdog is pinged and thus has zero value except for filling up the console log. > + timeout = maxtimeout; > + } > + timeout *= clkrate; > + > + writel_relaxed(timeout, 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); > + You should set the valid limits in the watchdog_device variable to have the infrastructure enforce it. Accepting all timeouts and then dumping a warning on the console each time the watchdog is pinged will create a lot of unnecessary console noise. Guenter > + 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; > + struct st_wdog *st_wdog; > + struct regmap *regmap; > + struct resource *res; > + struct clk *clk; > + void __iomem *base; > + int ret; > + > + /* This is a single node MFD device. */ > + np = pdev->dev.of_node = pdev->dev.parent->of_node; > + > + 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"); > + > + 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, > + }, > + .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"); >
On Mon, Dec 15, 2014 at 11:25:36AM +0000, 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 | 312 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 326 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..7e06f15 > --- /dev/null > +++ b/drivers/watchdog/st_wdt.c > @@ -0,0 +1,312 @@ > +/* > + * 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> > + > +/* Low Power Alarm */ > +#define LPC_LPA_LSB_OFF 0x410 > +#define LPC_LPA_START_OFF 0x418 > + > +/* LPC as WDT */ > +#define LPC_WDT_OFF 0x510 > + > +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; > + int 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 = clk_get_rate(st_wdog->clk); > + unsigned int maxtimeout = 0xFFFFFFFF / clkrate; > + Wondering ... is this re-calculation for each keepalive really necessary ? If yes (ie if the clock rate can change) that may be problematic, since a clock rate change might happen right after a keepalive, and the watchdog might time out if the clock rate increased. Not really sure if / how that problem could be solved unless it is possible to register a callback associated with clocks. If the clock rate does not change, it might be better to retrieve it once in probe, calculate maxtimeout there, and store it in the watchdog_device structure. Similar, clkrate can be stored in struct st_wdog (or just store timeout * clkrate so it doesn't have to be recalculated unnecessarily). Also, clk_get_rate can return 0, at least on some architectures/platforms. It might make sense to check its return value in the probe function. Thanks, Guenter > + if (timeout > maxtimeout) { > + dev_warn(st_wdog->dev, > + "timer overrun detected at current freq (%luHz)\n" > + "wdog timeout set for %ds instead of requested %uis", > + clkrate, maxtimeout, timeout); > + timeout = maxtimeout; > + } > + timeout *= clkrate; > + > + writel_relaxed(timeout, 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; > + struct st_wdog *st_wdog; > + struct regmap *regmap; > + struct resource *res; > + struct clk *clk; > + void __iomem *base; > + int ret; > + > + /* This is a single node MFD device. */ > + np = pdev->dev.of_node = pdev->dev.parent->of_node; > + > + 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"); > + > + 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, > + }, > + .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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-watchdog" 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 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..7e06f15 --- /dev/null +++ b/drivers/watchdog/st_wdt.c @@ -0,0 +1,312 @@ +/* + * 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> + +/* Low Power Alarm */ +#define LPC_LPA_LSB_OFF 0x410 +#define LPC_LPA_START_OFF 0x418 + +/* LPC as WDT */ +#define LPC_WDT_OFF 0x510 + +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; + int 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 = clk_get_rate(st_wdog->clk); + unsigned int maxtimeout = 0xFFFFFFFF / clkrate; + + if (timeout > maxtimeout) { + dev_warn(st_wdog->dev, + "timer overrun detected at current freq (%luHz)\n" + "wdog timeout set for %ds instead of requested %uis", + clkrate, maxtimeout, timeout); + timeout = maxtimeout; + } + timeout *= clkrate; + + writel_relaxed(timeout, 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; + struct st_wdog *st_wdog; + struct regmap *regmap; + struct resource *res; + struct clk *clk; + void __iomem *base; + int ret; + + /* This is a single node MFD device. */ + np = pdev->dev.of_node = pdev->dev.parent->of_node; + + 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"); + + 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, + }, + .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");