Re: [PATCH v5 1/4] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver

From: Lee Jones
Date: Wed Aug 27 2014 - 03:26:45 EST


On Tue, 26 Aug 2014, Andreas Werner wrote:
> The MEN 14F021P00 Board Management Controller provides an
> I2C interface to the host to access the feature implemented in the BMC.
> The BMC is a PIC Microntroller assembled on CPCI Card from MEN Mikroelektronik
> and on a few Box/Display Computer.
>
> Added MFD Core driver, supporting the I2C communication to the device.
>
> The MFD driver currently supports the following features:
> - Watchdog
> - LEDs
> - Hwmon (voltage monitoring)
>
> Signed-off-by: Andreas Werner <andreas.werner@xxxxxx>
> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
> drivers/mfd/Kconfig | 12 +++++
> drivers/mfd/Makefile | 1 +
> drivers/mfd/menf21bmc.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 145 insertions(+)
> create mode 100644 drivers/mfd/menf21bmc.c
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index b8d9ca0..6a9f101 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -453,6 +453,18 @@ config MFD_MAX8998
> additional drivers must be enabled in order to use the functionality
> of the device.
>
> +config MFD_MENF21BMC
> + tristate "MEN 14F021P00 Board Management Controller Support"
> + depends on I2C
> + select MFD_CORE
> + help
> + Say yes here to add support for the MEN 14F021P00 BMC
> + which is a Board Management Controller connected to the I2C bus.
> + The device supports multiple sub-devices like LED, HWMON and WDT.

Nit: Whitespace error.

> + This driver provides common support for accessing the devices;
> + additional drivers must be enabled in order to use the
> + functionality of the BMC device.
> +
> config EZX_PCAP
> bool "Motorola EZXPCAP Support"
> depends on SPI_MASTER
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 4e2bc25..37bf336 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -169,6 +169,7 @@ obj-$(CONFIG_MFD_AS3711) += as3711.o
> obj-$(CONFIG_MFD_AS3722) += as3722.o
> obj-$(CONFIG_MFD_STW481X) += stw481x.o
> obj-$(CONFIG_MFD_IPAQ_MICRO) += ipaq-micro.o
> +obj-$(CONFIG_MFD_MENF21BMC) += menf21bmc.o
>
> intel-soc-pmic-objs := intel_soc_pmic_core.o intel_soc_pmic_crc.o
> obj-$(CONFIG_INTEL_SOC_PMIC) += intel-soc-pmic.o
> diff --git a/drivers/mfd/menf21bmc.c b/drivers/mfd/menf21bmc.c
> new file mode 100644
> index 0000000..a6eb03f
> --- /dev/null
> +++ b/drivers/mfd/menf21bmc.c
> @@ -0,0 +1,132 @@
> +/*
> + * MEN 14F021P00 Board Management Controller (BMC) MFD Core 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/i2c.h>
> +#include <linux/mfd/core.h>
> +
> +#define BMC_CMD_WDT_EXIT_PROD 0x18
> +#define BMC_CMD_WDT_PROD_STAT 0x19
> +#define BMC_CMD_REV_MAJOR 0x80
> +#define BMC_CMD_REV_MINOR 0x81
> +#define BMC_CMD_REV_MAIN 0x82
> +
> +static struct mfd_cell menf21bmc_cell[] = {
> + { .name = "menf21bmc_wdt", },
> + { .name = "menf21bmc_led", },
> + { .name = "menf21bmc_hwmon", }
> +};
> +
> +static int menf21bmc_wdt_exit_prod_mode(struct i2c_client *client)
> +{
> + int val, ret;
> +
> + val = i2c_smbus_read_byte_data(client, BMC_CMD_WDT_PROD_STAT);
> + if (val < 0)
> + return val;
> +
> + /*
> + * 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.
> + */
> + if (val == 0x00) {
> + dev_info(&client->dev,
> + "BMC in production mode. Exit production mode\n");
> +
> + ret = i2c_smbus_write_byte(client, BMC_CMD_WDT_EXIT_PROD);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int
> +menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
> +{
> + int ret;
> + int rev_major, rev_minor, rev_main;

Really small nit (as you have to fix the whitespace err anyway):
Can you change the order of the two lines above please?

> + ret = i2c_check_functionality(client->adapter,
> + I2C_FUNC_SMBUS_BYTE_DATA |
> + I2C_FUNC_SMBUS_WORD_DATA |
> + I2C_FUNC_SMBUS_BYTE);
> + if (!ret)
> + return -ENODEV;
> +
> + rev_major = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAJOR);
> + if (rev_major < 0) {
> + dev_err(&client->dev, "failed to get BMC major revision\n");
> + return rev_major;
> + }
> +
> + rev_minor = i2c_smbus_read_word_data(client, BMC_CMD_REV_MINOR);
> + if (rev_minor < 0) {
> + dev_err(&client->dev, "failed to get BMC minor revision\n");
> + return rev_minor;
> + }
> +
> + rev_main = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAIN);
> + if (rev_main < 0) {
> + dev_err(&client->dev, "failed to get BMC main revision\n");
> + return rev_main;
> + }
> +
> + dev_info(&client->dev, "FW Revision: %02d.%02d.%02d\n",
> + rev_major, rev_minor, rev_main);

You enforced a 'line > 80 chars' warning in your other driver just so
you can 'do the right thing' and line up against the '('. :)

Can you do that here please?

> + /*
> + * 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");
> + return ret;
> + }
> +
> + ret = mfd_add_devices(&client->dev, 0, menf21bmc_cell,
> + ARRAY_SIZE(menf21bmc_cell), NULL, 0, NULL);

Line up to to '('.

> + if (ret < 0) {
> + dev_err(&client->dev, "failed to add BMC sub-devices\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int menf21bmc_remove(struct i2c_client *client)
> +{
> + mfd_remove_devices(&client->dev);
> + return 0;
> +}
> +
> +static const struct i2c_device_id menf21bmc_id_table[] = {
> + { "menf21bmc", 0 },

The second attribute is unused in this driver, please remove it.

> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, menf21bmc_id_table);
> +
> +static struct i2c_driver menf21bmc_driver = {
> + .driver.name = "menf21bmc",
> + .id_table = menf21bmc_id_table,
> + .probe = menf21bmc_probe,
> + .remove = menf21bmc_remove,
> +};

No DT support?

> +module_i2c_driver(menf21bmc_driver);
> +
> +MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");

s/mfd/MFD

> +MODULE_AUTHOR("Andreas Werner <andreas.werner@xxxxxx>");
> +MODULE_LICENSE("GPL v2");

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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