Re: [PATCH v4 3/4] drivers/leds/leds-menf21bmc: introduce MEN 14F021P00 BMC LED driver

Guenter Roeck
2014-08-25T19:06:07Z

On Mon, Aug 25, 2014 at 11:53:32AM -0700, Bryan Wu wrote:
> On Wed, Aug 13, 2014 at 1:40 AM, Andreas Werner <andreas.werner@men.de> wrote:
> > Added driver to support the 14F021P00 BMC LEDs.
> > The BMC is a Board Management Controller including four LEDs which
> > can be switched on and off.
> >
> > Signed-off-by: Andreas Werner <andreas.werner@men.de>
> > ---
> > drivers/leds/Kconfig | 6 ++
> > drivers/leds/Makefile | 1 +
> > drivers/leds/leds-menf21bmc.c | 131 ++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 138 insertions(+)
> > create mode 100644 drivers/leds/leds-menf21bmc.c
> >
> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> > index 27cf0cd..d38ff3f 100644
> > --- a/drivers/leds/Kconfig
> > +++ b/drivers/leds/Kconfig
> > @@ -458,6 +458,12 @@ config LEDS_OT200
> > This option enables support for the LEDs on the Bachmann OT200.
> > Say Y to enable LEDs on the Bachmann OT200.
> >
> > +config LEDS_MENF21BMC
> > + tristate "LED support for the MEN 14F021P00 BMC"
> > + depends on LEDS_CLASS && MFD_MENF21BMC
> > + help
> > + Say Y here to include support for the MEN 14F021P00 BMC LEDs.
> > +
> > comment "LED driver for blink(1) USB RGB LED is under Special HID drivers (HID_THINGM)"
> >
> > config LEDS_BLINKM
> > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> > index 3c03666..cadc433 100644
> > --- a/drivers/leds/Makefile
> > +++ b/drivers/leds/Makefile
> > @@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_MAX8997) += leds-max8997.o
> > obj-$(CONFIG_LEDS_LM355x) += leds-lm355x.o
> > obj-$(CONFIG_LEDS_BLINKM) += leds-blinkm.o
> > obj-$(CONFIG_LEDS_VERSATILE) += leds-versatile.o
> > +obj-$(CONFIG_LEDS_MENF21BMC) += leds-menf21bmc.o
> >
> > # LED SPI Drivers
> > obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o
> > diff --git a/drivers/leds/leds-menf21bmc.c b/drivers/leds/leds-menf21bmc.c
> > new file mode 100644
> > index 0000000..4621f72
> > --- /dev/null
> > +++ b/drivers/leds/leds-menf21bmc.c
> > @@ -0,0 +1,131 @@
> > +/*
> > + * MEN 14F021P00 Board Management Controller (BMC) LEDs Driver.
> > + *
> > + * This is the core LED driver of the MEN 14F021P00 BMC.
> > + * There are four LEDs available which can be switched on and off.
> > + * STATUS LED, HOT SWAP LED, USER LED 1, USER LED 2
> > + *
> > + * 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/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/leds.h>
> > +#include <linux/i2c.h>
> > +
> > +#define BMC_CMD_LED_GET_SET 0xA0
> > +#define BMC_BIT_LED_STATUS BIT(0)
> > +#define BMC_BIT_LED_HOTSWAP BIT(1)
> > +#define BMC_BIT_LED_USER1 BIT(2)
> > +#define BMC_BIT_LED_USER2 BIT(3)
> > +
> > +struct menf21bmc_led {
> > + struct led_classdev cdev;
> > + u8 led_bit;
> > + const char *name;
> > + struct i2c_client *i2c_client;
> > +};
> > +
> > +static struct menf21bmc_led leds[] = {
> > + {
> > + .name = "menf21bmc:led_status",
> > + .led_bit = BMC_BIT_LED_STATUS,
> > + },
> > + {
> > + .name = "menf21bmc:led_hotswap",
> > + .led_bit = BMC_BIT_LED_HOTSWAP,
> > + },
> > + {
> > + .name = "menf21bmc:led_user1",
> > + .led_bit = BMC_BIT_LED_USER1,
> > + },
> > + {
> > + .name = "menf21bmc:led_user2",
> > + .led_bit = BMC_BIT_LED_USER2,
> > + }
> > +};
> > +
> > +static DEFINE_MUTEX(led_lock);
> > +
> > +static void
> > +menf21bmc_led_set(struct led_classdev *led_cdev, enum led_brightness value)
> > +{
> > + int led_val;
> > + struct menf21bmc_led *led = container_of(led_cdev,
> > + struct menf21bmc_led, cdev);
> > +
> > + mutex_lock(&led_lock);
> > + led_val = i2c_smbus_read_byte_data(led->i2c_client,
> > + BMC_CMD_LED_GET_SET);
> > + if (led_val < 0)
> > + goto err_out;
> > +
> > + if (value == LED_OFF)
> > + led_val &= ~led->led_bit;
> > + else
> > + led_val |= led->led_bit;
> > +
> > + i2c_smbus_write_byte_data(led->i2c_client,
> > + BMC_CMD_LED_GET_SET, led_val);
> > +err_out:
> > + mutex_unlock(&led_lock);
> > +}
> > +
> > +static int menf21bmc_led_probe(struct platform_device *pdev)
> > +{
> > + int i;
> > + int ret;
> > + struct i2c_client *i2c_client = to_i2c_client(pdev->dev.parent);
> > +
> > + for (i = 0; i < ARRAY_SIZE(leds); i++) {
> > + leds[i].cdev.name = leds[i].name;
> > + leds[i].cdev.brightness_set = menf21bmc_led_set;
> > + leds[i].i2c_client = i2c_client;
> > + ret = led_classdev_register(&pdev->dev, &leds[i].cdev);
> > + if (ret < 0)
> > + goto err_free_leds;
> > + }
> > + dev_info(&pdev->dev, "MEN 140F21P00 BMC LED device enabled\n");
> > +
> > + return 0;
> > +
> > +err_free_leds:
> > + dev_err(&pdev->dev, "failed to register LED device\n");
> > +
> > + for (i = i - 1; i >= 0; i--)
> > + led_classdev_unregister(&leds[i].cdev);
> > +
> > + return ret;
> > +}
> > +
> > +static int menf21bmc_led_remove(struct platform_device *pdev)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(leds); i++)
> > + led_classdev_unregister(&leds[i].cdev);
> > +
> > + return 0;
> > +}
> > +
> > +static struct platform_driver menf21bmc_led = {
> > + .probe = menf21bmc_led_probe,
> > + .remove = menf21bmc_led_remove,
> > + .driver = {
> > + .name = "menf21bmc_led",
> > + .owner = THIS_MODULE,
> > + },
> > +};
> > +
>
> I still think this driver should be an I2C driver which is simply than
> a platform driver.
> Did I miss some discussion about this in our email?
>
It is not possible to instantiate multiple drivers (watchdog, hwmon, led
in this case) with a single i2c chip.

Thanks,
Guenter