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Date: Sat, 17 May 2014 08:57:27 -0700
From: Guenter Roeck <linux@...ck-us.net>
To: Andreas Werner <andreas.werner@....de>,
linux-kernel@...r.kernel.org
CC: sameo@...ux.intel.com, lee.jones@...aro.org, wim@...ana.be,
linux-watchdog@...r.kernel.org, cooloney@...il.com,
rpurdie@...ys.net, linux-leds@...r.kernel.org,
johannes.thumshirn@....de, thomas.schnuerer@....de,
wernerandy@....de
Subject: Re: [PATCH 2/3] drivers/watchdog/menf21bmc_wd: introduce MEN 14F021P00
BMC Watchdog driver
On 05/16/2014 09:37 AM, Andreas Werner wrote:
> Added driver to support the 14F021P00 BMC Watchdog.
> The BMC is a Board Management Controller including watchdog functionality.
>
> This driver use the I2C interface to the BMC using the menf21bmc MFD Core driver.
>
> Signed-off-by: Andreas Werner <andreas.werner@....de>
> ---
> drivers/watchdog/Kconfig | 7 ++
> drivers/watchdog/Makefile | 1 +
> drivers/watchdog/menf21bmc_wd.c | 263 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 271 insertions(+)
> create mode 100644 drivers/watchdog/menf21bmc_wd.c
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 2b4c1fc..ede3201 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 1b5f3d5..0a5465d 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_wd.o
> diff --git a/drivers/watchdog/menf21bmc_wd.c b/drivers/watchdog/menf21bmc_wd.c
> new file mode 100644
> index 0000000..31ccea8
> --- /dev/null
> +++ b/drivers/watchdog/menf21bmc_wd.c
> @@ -0,0 +1,263 @@
> +/*
> + * MEN 14F021P00 Board Management Controller (BMC) Watchdog Driver.
> + *
> + * Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
> + * Author: Andreas Werner <andreas.werner@....de>
> + * All rights reserved.
> + *
> + * 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/mfd/menf21bmc.h>
> +
> +#define DEVNAME "menf21bmc_wd"
> +
> +#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_CMD_WD_ARM_SET 0x18
> +#define BMC_CMD_WD_ARM_GET 0x19
> +#define BMC_CMD_ARM_STATE 0x19
> +#define BMC_WD_OFF_VAL 0x69
> +#define BMC_CMD_RST_RSN 0x92
> +
> +#define BMC_WD_TIMEOUT_MIN 1 /* in sec -> BMC min = 0.1 s */
I find the comment a bit confusing. The timeout is in seconds. The BMC minimum
timeout may be 0.1s, but that is not reflected in the define. Maybe replace
the comment with something like
/* in sec (BMC min = 0.1 s) */
> +#define BMC_WD_TIMEOUT_MAX 6553 /* in sec -> BMC max = 6553,5 s */
> +
> +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_wd_data {
> + struct watchdog_device wdt;
> + struct menf21bmc *menf21bmc;
> +};
> +
> +static int menf21bmc_wd_set_bootstatus(struct menf21bmc_wd_data *data)
> +{
> + u8 rst_rsn;
> + int ret;
> + struct menf21bmc *menf21bmc = data->menf21bmc;
> +
> + ret = menf21bmc->read_byte_data(menf21bmc->client,
> + BMC_CMD_RST_RSN, &rst_rsn);
> + if (ret < 0)
> + return -EIO;
> +
Please return the original error.
> + 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_wd_leave_prod_mode(struct platform_device *pdev)
> +{
> + int ret;
> + uint8_t val;
> + struct menf21bmc_wd_data *data = platform_get_drvdata(pdev);
> + struct menf21bmc *menf21bmc = data->menf21bmc;
> +
> + ret = menf21bmc->read_byte_data(menf21bmc->client,
> + BMC_CMD_WD_ARM_GET, &val);
> + if (ret < 0)
> + return -EIO;
> +
Please return the original error.
> + /*
> + * Production mode should be not active after delivery of the Board.
> + * To be sure we check it, inform the user and leave the mode
> + * if active.
> + */
> + if (val == 0x00) {
> + dev_info(&pdev->dev,
> + "BMC in production mode. Leave production mode\n");
> +
> + ret = menf21bmc->write_byte(menf21bmc->client,
> + BMC_CMD_WD_ARM_SET);
> + if (ret < 0)
> + return -EIO;
Please return the original error.
> + }
> +
> + return 0;
> +}
> +
> +static int menf21bmc_wd_start(struct watchdog_device *wdt)
> +{
> + struct menf21bmc_wd_data *data = watchdog_get_drvdata(wdt);
> + struct menf21bmc *menf21bmc = data->menf21bmc;
> +
> + return menf21bmc->write_byte(menf21bmc->client, BMC_CMD_WD_ON);
> +}
> +
> +static int menf21bmc_wd_stop(struct watchdog_device *wdt)
> +{
> + struct menf21bmc_wd_data *data = watchdog_get_drvdata(wdt);
> + struct menf21bmc *menf21bmc = data->menf21bmc;
> +
> + return menf21bmc->write_byte_data(menf21bmc->client,
> + BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
> +}
> +
> +static int
> +menf21bmc_wd_settimeout(struct watchdog_device *wdt, unsigned int timeout)
> +{
> + int ret;
> + struct menf21bmc_wd_data *data = watchdog_get_drvdata(wdt);
> + struct menf21bmc *menf21bmc = data->menf21bmc;
> +
> + /*
> + * BMC Watchdog does have a resolution of 100ms.
> + * Watchdog API defines the timeout in seconds, so we have to
> + * multiply the value.
> + */
> + ret = menf21bmc->write_word_data(menf21bmc->client,
> + BMC_CMD_WD_TIME, timeout * 10);
> + if (ret < 0)
> + return -EIO;
> +
Please return the original error.
> + wdt->timeout = timeout;
> +
> + return 0;
> +}
> +
> +static int menf21bmc_wd_ping(struct watchdog_device *wdt)
> +{
> + struct menf21bmc_wd_data *data = watchdog_get_drvdata(wdt);
> + struct menf21bmc *menf21bmc = data->menf21bmc;
> +
> + return menf21bmc->write_byte(menf21bmc->client, BMC_CMD_WD_TRIG);
> +}
> +
> +static const struct watchdog_info menf21bmc_wd_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
> + .identity = DEVNAME,
> +};
> +
> +static const struct watchdog_ops menf21bmc_wd_ops = {
> + .owner = THIS_MODULE,
> + .start = menf21bmc_wd_start,
> + .stop = menf21bmc_wd_stop,
> + .ping = menf21bmc_wd_ping,
> + .set_timeout = menf21bmc_wd_settimeout,
> +};
> +
> +static int menf21bmc_wd_probe(struct platform_device *pdev)
> +{
> + int ret;
> + uint16_t bmc_timeout;
> + struct menf21bmc_wd_data *driver_data;
> + struct watchdog_device *menf21bmc_wd;
> + struct menf21bmc *menf21bmc = dev_get_drvdata(pdev->dev.parent);
> +
> + driver_data = devm_kzalloc(&pdev->dev,
> + sizeof(struct menf21bmc_wd_data), GFP_KERNEL);
> + if (!driver_data)
> + return -ENOMEM;
> +
> + driver_data->menf21bmc = menf21bmc;
> +
> + menf21bmc_wd = &driver_data->wdt;
> + menf21bmc_wd->ops = &menf21bmc_wd_ops;
> + menf21bmc_wd->info = &menf21bmc_wd_info;
> + menf21bmc_wd->min_timeout = BMC_WD_TIMEOUT_MIN;
> + menf21bmc_wd->max_timeout = BMC_WD_TIMEOUT_MAX;
> +
> +
Please no more than one empty line.
> + /*
> + * Get the current wdt timeout value from the BMC because
> + * the BMC will save the value set before if the system restarts.
> + */
> + ret = menf21bmc->read_word_data(menf21bmc->client,
> + BMC_CMD_WD_TIME, &bmc_timeout);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to get current WDT timeout\n");
> + return ret;
> + }
> +
> + watchdog_init_timeout(menf21bmc_wd, bmc_timeout / 10, &pdev->dev);
> +
> + watchdog_set_nowayout(menf21bmc_wd, nowayout);
> + watchdog_set_drvdata(menf21bmc_wd, driver_data);
> + platform_set_drvdata(pdev, driver_data);
> +
> + /*
> + * We have to leave the Production Mode of the BMC to activate the
> + * Watchdog functionality.
> + */
> + ret = menf21bmc_wd_leave_prod_mode(pdev);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to leave production mode\n");
> + return ret;
> + }
> +
Shouldn't this be in the mfd code ?
> + ret = menf21bmc_wd_set_bootstatus(driver_data);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to set Watchdog bootstatus\n");
> + return ret;
> + }
> +
> + ret = watchdog_register_device(&driver_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_wd_remove(struct platform_device *pdev)
> +{
> + struct menf21bmc_wd_data *data = platform_get_drvdata(pdev);
> +
> + dev_warn(&pdev->dev,
> + "Untregister MEN 14F021P00 BMC Watchdog device, board may reset\n");
> +
> + watchdog_unregister_device(&data->wdt);
> +
> + return 0;
> +}
> +
> +static void menf21bmc_wd_shutdown(struct platform_device *pdev)
> +{
> + struct menf21bmc_wd_data *data = platform_get_drvdata(pdev);
> + struct menf21bmc *menf21bmc = data->menf21bmc;
> +
> + menf21bmc->write_word_data(menf21bmc->client,
> + BMC_CMD_WD_OFF, BMC_WD_OFF_VAL);
> +}
> +
> +static struct platform_driver menf21bmc_wd = {
> + .driver = {
> + .owner = THIS_MODULE,
> + .name = DEVNAME,
> + },
> + .probe = menf21bmc_wd_probe,
> + .remove = menf21bmc_wd_remove,
> + .shutdown = menf21bmc_wd_shutdown,
> +};
> +
> +module_platform_driver(menf21bmc_wd);
> +
> +MODULE_DESCRIPTION("MEN 14F021P00 BMC Watchdog driver");
> +MODULE_AUTHOR("Andreas Werner <andreas.werner@....de>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:menf21bmc_wd");
>
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