Re: [PATCH v2 1/4] mfd: menf21bmc: Remove auto exiting of production mode and add sysfs interface

From: Lee Jones
Date: Mon Jan 25 2016 - 11:09:36 EST


On Mon, 11 Jan 2016, Andreas Werner wrote:

> Changed "exit production mode" from automatic exiting to
> manually using the sysfs interface.
>
> If the driver exit the production mode automatically, the board will
> not start anymore if the bootloader does not already have the "BIOS life sign"
> feature.
>
> This patch remove the auto mechanism and add a sysfs interface to manually
> exiting the production e.g. during the EOL test of the board.
>
> Signed-off-by: Andreas Werner <andreas.werner@xxxxxx>
> ---
> drivers/mfd/menf21bmc.c | 65 +++++++++++++++++++++++++++++++++----------------
> 1 file changed, 44 insertions(+), 21 deletions(-)

Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>

> diff --git a/drivers/mfd/menf21bmc.c b/drivers/mfd/menf21bmc.c
> index 1c27434..b11bd6b 100644
> --- a/drivers/mfd/menf21bmc.c
> +++ b/drivers/mfd/menf21bmc.c
> @@ -27,31 +27,57 @@ static struct mfd_cell menf21bmc_cell[] = {
> { .name = "menf21bmc_hwmon", }
> };
>
> -static int menf21bmc_wdt_exit_prod_mode(struct i2c_client *client)
> +static ssize_t menf21bmc_mode_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> {
> - int val, ret;
> + struct i2c_client *client = to_i2c_client(dev);
> + int val;
>
> val = i2c_smbus_read_byte_data(client, BMC_CMD_WDT_PROD_STAT);
> if (val < 0)
> return val;
>
> + return sprintf(buf, "%d\n", val);
> +}
> +
> +static ssize_t menf21bmc_mode_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t size)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + unsigned long mode_val;
> + int ret;
> +
> + if (kstrtoul(buf, 0, &mode_val))
> + return -EINVAL;
> +
> /*
> - * Production mode should be not active after delivery of the Board.
> - * To be sure we check it, inform the user and exit the mode
> - * if active.
> + * We cannot set the production mode (0).
> + * This is the default mode. If exited once,
> + * it cannot be set anymore.
> */
> - if (val == 0x00) {
> - dev_info(&client->dev,
> - "BMC in production mode. Exit production mode\n");
> + if (!mode_val)
> + return -EINVAL;
>
> - ret = i2c_smbus_write_byte(client, BMC_CMD_WDT_EXIT_PROD);
> - if (ret < 0)
> - return ret;
> - }
> + ret = i2c_smbus_write_byte(client, BMC_CMD_WDT_EXIT_PROD);
> + if (ret < 0)
> + return ret;
>
> - return 0;
> + return size;
> }
>
> +static DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, menf21bmc_mode_show,
> + menf21bmc_mode_store);
> +
> +static struct attribute *menf21bmc_attributes[] = {
> + &dev_attr_mode.attr,
> + NULL
> +};
> +
> +static const struct attribute_group menf21bmc_attr_group = {
> + .attrs = menf21bmc_attributes,
> +};
> +
> static int
> menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
> {
> @@ -86,20 +112,15 @@ menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
> dev_info(&client->dev, "FW Revision: %02d.%02d.%02d\n",
> rev_major, rev_minor, rev_main);
>
> - /*
> - * We have to exit the Production Mode of the BMC to activate the
> - * Watchdog functionality and the BIOS life sign monitoring.
> - */
> - ret = menf21bmc_wdt_exit_prod_mode(client);
> - if (ret < 0) {
> - dev_err(&client->dev, "failed to leave production mode\n");
> + ret = sysfs_create_group(&client->dev.kobj, &menf21bmc_attr_group);
> + if (ret)
> return ret;
> - }
>
> ret = mfd_add_devices(&client->dev, 0, menf21bmc_cell,
> ARRAY_SIZE(menf21bmc_cell), NULL, 0, NULL);
> if (ret < 0) {
> dev_err(&client->dev, "failed to add BMC sub-devices\n");
> + sysfs_remove_group(&client->dev.kobj, &menf21bmc_attr_group);
> return ret;
> }
>
> @@ -108,7 +129,9 @@ menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
>
> static int menf21bmc_remove(struct i2c_client *client)
> {
> + sysfs_remove_group(&client->dev.kobj, &menf21bmc_attr_group);
> mfd_remove_devices(&client->dev);
> +
> return 0;
> }
>

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog