Re: [PATCH V2 8/8] watchdog: stpmic1: add stpmic1 watchdog driver
From: Guenter Roeck <linux@roeck-us.net>
Date: 2018-09-07 13:48:08
Also in:
linux-devicetree, linux-watchdog, lkml
On 09/07/2018 05:59 AM, Pascal PAILLET-LME wrote:
From: pascal paillet <redacted> The stpmic1 PMIC embeds a watchdog which is disabled by default. As soon as the watchdog is started, it must be refreshed periodically otherwise the PMIC goes off. Signed-off-by: pascal paillet <redacted> --- changes in v2: * the hardware component has been renamed from stpmu1 to stpmic1 ! * change headers * handle remarks from Guenter
Hmm ... as if I would remember what those were.
quoted hunk ↗ jump to hunk
* fix set timeout drivers/watchdog/Kconfig | 12 ++++ drivers/watchdog/Makefile | 1 + drivers/watchdog/stpmic1_wdt.c | 130 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 143 insertions(+) create mode 100644 drivers/watchdog/stpmic1_wdt.cdiff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 9af07fd..11c5937 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig@@ -796,6 +796,18 @@ config STM32_WATCHDOG To compile this driver as a module, choose M here: the module will be called stm32_iwdg. +config STPMIC1_WATCHDOG + tristate "STPMIC1 PMIC watchdog support" + depends on MFD_STPMIC1 + select WATCHDOG_CORE + help + Say Y here to include watchdog support embedded into STPMIC1 PMIC. + If the watchdog timer expires, stpmic1 shut-down all its power + supplies. + + To compile this driver as a module, choose M here: the + module will be called spmic1_wdt. + config UNIPHIER_WATCHDOG tristate "UniPhier watchdog support" depends on ARCH_UNIPHIER || COMPILE_TESTdiff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 1d3c6b0..a898d8f 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile@@ -216,3 +216,4 @@ obj-$(CONFIG_ZIIRAVE_WATCHDOG) += ziirave_wdt.o obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o +obj-$(CONFIG_STPMIC1_WATCHDOG) += stpmic1_wdt.odiff --git a/drivers/watchdog/stpmic1_wdt.c b/drivers/watchdog/stpmic1_wdt.c new file mode 100644 index 0000000..391e544 --- /dev/null +++ b/drivers/watchdog/stpmic1_wdt.c@@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) STMicroelectronics 2018 +// Author: Pascal Paillet <p.paillet@st.com> for STMicroelectronics. + > +#include <linux/kernel.h> +#include <linux/mfd/stpmic1.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/regmap.h> +#include <linux/reboot.h> +#include <linux/slab.h> +#include <linux/watchdog.h> + +/* WATCHDOG CONTROL REGISTER bit */ +#define WDT_START BIT(0) +#define WDT_PING BIT(1) +#define WDT_START_MASK BIT(0) +#define WDT_PING_MASK BIT(1) + +#define PMIC_WDT_MIN_TIMEOUT 1 +#define PMIC_WDT_MAX_TIMEOUT 256 + +struct stpmic1_wdt { + struct stpmic1_dev *pmic; + struct watchdog_device wdtdev; +}; + +static int pmic_wdt_start(struct watchdog_device *wdd) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_START_MASK, WDT_START); +} + +static int pmic_wdt_stop(struct watchdog_device *wdd) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_START_MASK, ~WDT_START); +} + +static int pmic_wdt_ping(struct watchdog_device *wdd) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_update_bits(wdt->pmic->regmap, + WCHDG_CR, WDT_PING_MASK, WDT_PING); +} + +static int pmic_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct stpmic1_wdt *wdt = watchdog_get_drvdata(wdd); + + return regmap_write(wdt->pmic->regmap, WCHDG_TIMER_CR, timeout - 1);
What happens if the configured timeout is 1 ? Does that translate to a 1-second timeout ? This function also has to set wdd->timeout.
+}
+
+static const struct watchdog_info pmic_watchdog_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,No WDIOF_MAGICCLOSE ?
+ .identity = "STPMIC1 PMIC Watchdog",
+};
+
+static const struct watchdog_ops pmic_watchdog_ops = {
+ .owner = THIS_MODULE,
+ .start = pmic_wdt_start,
+ .stop = pmic_wdt_stop,
+ .ping = pmic_wdt_ping,
+ .set_timeout = pmic_wdt_set_timeout,
+};
+
+static int pmic_wdt_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct stpmic1_dev *pmic;
+ struct stpmic1_wdt *wdt;
+
+ if (!pdev->dev.parent)
+ return -EINVAL;
+
+ pmic = dev_get_drvdata(pdev->dev.parent);
+ if (!pmic)
+ return -EINVAL;
+
+ wdt = devm_kzalloc(&pdev->dev, sizeof(struct stpmic1_wdt), GFP_KERNEL);
+ if (!wdt)
+ return -ENOMEM;
+
+ wdt->pmic = pmic;
+
+ wdt->wdtdev.info = &pmic_watchdog_info;
+ wdt->wdtdev.ops = &pmic_watchdog_ops;
+ wdt->wdtdev.min_timeout = PMIC_WDT_MIN_TIMEOUT;
+ wdt->wdtdev.max_timeout = PMIC_WDT_MAX_TIMEOUT;
+ wdt->wdtdev.timeout = PMIC_WDT_MIN_TIMEOUT;Are you sure about that ? A timeout of 1 second may be a cause for unexpected reboots if user space is busy. Personally I find it better to set a larger default and let userspace configure a tighter value if so desired. Also, watchdog_init_timeout(&wdt->wdtdev, 0, &pdev->dev); might be desirable if you want to be able to specify the timeout in the devicetree file.
+ + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; + + watchdog_set_drvdata(&wdt->wdtdev, wdt); + dev_set_drvdata(&pdev->dev, wdt);
Unless I am missing something this should not be needed.
+
+ ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev);
+ if (ret)
+ return ret;
+
+ dev_dbg(wdt->pmic->dev, "PMIC Watchdog driver probed\n");
+ return 0;
+}
+
+static const struct of_device_id of_pmic_wdt_match[] = {
+ { .compatible = "st,stpmic1-wdt" },
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, of_pmic_wdt_match);
+
+static struct platform_driver stpmic1_wdt_driver = {
+ .probe = pmic_wdt_probe,
+ .driver = {
+ .name = "stpmic1-wdt",
+ .of_match_table = of_pmic_wdt_match,
+ },
+};
+module_platform_driver(stpmic1_wdt_driver);
+
+MODULE_DESCRIPTION("Watchdog driver for STPMIC1 device");
+MODULE_AUTHOR("Pascal Paillet");
+MODULE_LICENSE("GPL v2");