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

From: Andreas Werner
Date: Wed Aug 27 2014 - 05:44:53 EST


On Wed, Aug 27, 2014 at 08:26:33AM +0100, Lee Jones wrote:
> 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.
>

Forgot to run checkpatch on Kconfig since the last change. Will fix it.

> > + 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?

No problem.

>
> > + 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?
>

yes

> > + /*
> > + * 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 '('.
>

ok

> > + 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.
>

ok

> > + { }
> > +};
> > +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
> Follow Linaro: Facebook | Twitter | Blog
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