[PATCH v4 2/4] drivers/watchdog/menf21bmc_wdt: introduce MEN 14F021P00 BMC Watchdog driver

Andreas Werner
2014-08-13T07:48:09Z

Added driver to support the 14F021P00 BMC Watchdog.
The BMC is a Board Management Controller including watchdog functionality.

Signed-off-by: Andreas Werner <andreas.werner@men.de>
---
drivers/watchdog/Kconfig | 7 ++
drivers/watchdog/Makefile | 1 +
drivers/watchdog/menf21bmc_wdt.c | 203 +++++++++++++++++++++++++++++++++++++++
3 files changed, 211 insertions(+)
create mode 100644 drivers/watchdog/menf21bmc_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 76dd541..f96431d 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -95,6 +95,13 @@ config GPIO_WATCHDOG
If you say yes here you get support for watchdog device
controlled through GPIO-line.

+config MENF21BMC_WATCHDOG
+ tristate "MEN 14F021P00 BMC Watchdog"
+ depends on MFD_MENF21BMC
+ select WATCHDOG_CORE
+ help
+ Say Y here to include support for the MEN 14F021P00 BMC Watchdog.
+
config WM831X_WATCHDOG
tristate "WM831x watchdog"
depends on MFD_WM831X
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 468c320..de17014 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -178,3 +178,4 @@ obj-$(CONFIG_WM831X_WATCHDOG) += wm831x_wdt.o
obj-$(CONFIG_WM8350_WATCHDOG) += wm8350_wdt.o
obj-$(CONFIG_MAX63XX_WATCHDOG) += max63xx_wdt.o
obj-$(CONFIG_SOFT_WATCHDOG) += softdog.o
+obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o
diff --git a/drivers/watchdog/menf21bmc_wdt.c b/drivers/watchdog/menf21bmc_wdt.c
new file mode 100644
index 0000000..604824d
--- /dev/null
+++ b/drivers/watchdog/menf21bmc_wdt.c
@@ -0,0 +1,203 @@
+/*
+ * MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
+ *
+ * Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+
+#define DEVNAME "menf21bmc_wdt"
+
+#define BMC_CMD_WD_ON 0x11
+#define BMC_CMD_WD_OFF 0x12
+#define BMC_CMD_WD_TRIG 0x13
+#define BMC_CMD_WD_TIME 0x14
+#define BMC_CMD_WD_STATE 0x17
+#define BMC_WD_OFF_VAL 0x69
+#define BMC_CMD_RST_RSN 0x92
+
+#define BMC_WD_TIMEOUT_MIN 1 /* in sec */
+#define BMC_WD_TIMEOUT_MAX 6553 /* in sec */
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct menf21bmc_wdt {
+ struct watchdog_device wdt;
+ struct i2c_client *i2c_client;
+};
+
+static int menf21bmc_wdt_set_bootstatus(struct menf21bmc_wdt *data)
+{
+ int rst_rsn;
+
+ rst_rsn = i2c_smbus_read_byte_data(data->i2c_client, BMC_CMD_RST_RSN);
+ if (rst_rsn < 0)
+ return rst_rsn;
+
+ if (rst_rsn == 0x02)
+ data->wdt.bootstatus |= WDIOF_CARDRESET;
+ else if (rst_rsn == 0x05)
+ data->wdt.bootstatus |= WDIOF_EXTERN1;
+ else if (rst_rsn == 0x06)
+ data->wdt.bootstatus |= WDIOF_EXTERN2;
+ else if (rst_rsn == 0x0A)
+ data->wdt.bootstatus |= WDIOF_POWERUNDER;
+
+ return 0;
+}
+
+static int menf21bmc_wdt_start(struct watchdog_device *wdt)
+{
+ struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+ return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_ON);
+}
+
+static int menf21bmc_wdt_stop(struct watchdog_device *wdt)
+{
+ struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+ return i2c_smbus_write_byte_data(drv_data->i2c_client,
+ BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
+}
+
+static int
+menf21bmc_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)
+{
+ int ret;
+ struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+ /*
+ * BMC Watchdog does have a resolution of 100ms.
+ * Watchdog API defines the timeout in seconds, so we have to
+ * multiply the value.
+ */
+ ret = i2c_smbus_write_word_data(drv_data->i2c_client,
+ BMC_CMD_WD_TIME, timeout * 10);
+ if (ret < 0)
+ return ret;
+
+ wdt->timeout = timeout;
+
+ return 0;
+}
+
+static int menf21bmc_wdt_ping(struct watchdog_device *wdt)
+{
+ struct menf21bmc_wdt *drv_data = watchdog_get_drvdata(wdt);
+
+ return i2c_smbus_write_byte(drv_data->i2c_client, BMC_CMD_WD_TRIG);
+}
+
+static const struct watchdog_info menf21bmc_wdt_info = {
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+ .identity = DEVNAME,
+};
+
+static const struct watchdog_ops menf21bmc_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = menf21bmc_wdt_start,
+ .stop = menf21bmc_wdt_stop,
+ .ping = menf21bmc_wdt_ping,
+ .set_timeout = menf21bmc_wdt_settimeout,
+};
+
+static int menf21bmc_wdt_probe(struct platform_device *pdev)
+{
+ int ret, bmc_timeout;
+ struct menf21bmc_wdt *drv_data;
+ struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
+
+ drv_data = devm_kzalloc(&pdev->dev,
+ sizeof(struct menf21bmc_wdt), GFP_KERNEL);
+ if (!drv_data)
+ return -ENOMEM;
+
+ drv_data->wdt.ops = &menf21bmc_wdt_ops;
+ drv_data->wdt.info = &menf21bmc_wdt_info;
+ drv_data->wdt.min_timeout = BMC_WD_TIMEOUT_MIN;
+ drv_data->wdt.max_timeout = BMC_WD_TIMEOUT_MAX;
+ drv_data->i2c_client = i2c_client;
+
+ /*
+ * Get the current wdt timeout value from the BMC because
+ * the BMC will save the value set before if the system restarts.
+ */
+ bmc_timeout = i2c_smbus_read_word_data(drv_data->i2c_client,
+ BMC_CMD_WD_TIME);
+ if (bmc_timeout < 0) {
+ dev_err(&pdev->dev, "failed to get current WDT timeout\n");
+ return bmc_timeout;
+ }
+
+ watchdog_init_timeout(&drv_data->wdt, bmc_timeout / 10, &pdev->dev);
+ watchdog_set_nowayout(&drv_data->wdt, nowayout);
+ watchdog_set_drvdata(&drv_data->wdt, drv_data);
+ platform_set_drvdata(pdev, drv_data);
+
+ ret = menf21bmc_wdt_set_bootstatus(drv_data);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n");
+ return ret;
+ }
+
+ ret = watchdog_register_device(&drv_data->wdt);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to register Watchdog device\n");
+ return ret;
+ }
+
+ dev_info(&pdev->dev, "MEN 14F021P00 BMC Watchdog device enabled\n");
+
+ return 0;
+}
+
+static int menf21bmc_wdt_remove(struct platform_device *pdev)
+{
+ struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
+
+ dev_warn(&pdev->dev,
+ "Unregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
+
+ watchdog_unregister_device(&drv_data->wdt);
+
+ return 0;
+}
+
+static void menf21bmc_wdt_shutdown(struct platform_device *pdev)
+{
+ struct menf21bmc_wdt *drv_data = platform_get_drvdata(pdev);
+
+ i2c_smbus_write_word_data(drv_data->i2c_client,
+ BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
+}
+
+static struct platform_driver menf21bmc_wdt = {
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DEVNAME,
+ },
+ .probe = menf21bmc_wdt_probe,
+ .remove = menf21bmc_wdt_remove,
+ .shutdown = menf21bmc_wdt_shutdown,
+};
+
+module_platform_driver(menf21bmc_wdt);
+
+MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:menf21bmc_wdt");
--
2.0.4