On 05/19/2014 05:43 AM, Andreas Werner wrote:
aOn Sat, May 17, 2014 at 08:47:42AM -0700, Guenter Roeck wrote:
On 05/16/2014 09:37 AM, 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

Signed-off-by: Andreas Werner <andreas.wer...@men.de>
---
  drivers/mfd/Kconfig           |  12 +++
  drivers/mfd/Makefile          |   1 +
  drivers/mfd/menf21bmc.c       | 193 ++++++++++++++++++++++++++++++++++++++++++
  include/linux/mfd/menf21bmc.h |  32 +++++++
  4 files changed, 238 insertions(+)
  create mode 100644 drivers/mfd/menf21bmc.c
  create mode 100644 include/linux/mfd/menf21bmc.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index ab5a43c..7c2e8d2 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -427,6 +427,18 @@ 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=y
+       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.
+         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 5913208..8f2be38 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -167,3 +167,4 @@ 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
diff --git a/drivers/mfd/menf21bmc.c b/drivers/mfd/menf21bmc.c
new file mode 100644
index 0000000..77de1a8
--- /dev/null
+++ b/drivers/mfd/menf21bmc.c
@@ -0,0 +1,193 @@
+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) MFD Core Driver.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ *  Author: Andreas Werner <andreas.wer...@men.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/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/menf21bmc.h>
+
+#define BMC_CMD_REV_MAJOR      0x80
+#define BMC_CMD_REV_MINOR      0x81
+#define BMC_CMD_REV_MAIN       0x82
+#define BMC_CMD_REV_BUILD      0x83
+#define BMC_CMD_REV_VERI       0x84
+
+static struct mfd_cell menf21bmc_cell[] = {
+       {
+               .name = "menf21bmc_wd",
+       },
+       {
+               .name = "menf21bmc_led",
+       },
+};
+
+static int
+menf21bmc_read_byte_data(struct i2c_client *client, u8 reg, uint8_t *val)
+{
+       int ret;
+       struct menf21bmc *data = i2c_get_clientdata(client);
+
+       mutex_lock(&data->lock);
+       ret = i2c_smbus_read_byte_data(client, reg);
+       mutex_unlock(&data->lock);
+
+       if (ret < 0) {
+               dev_err(&client->dev, "failed to read byte at 0x%02x\n", reg);
+               return ret;
+       }
+
+       *val = (uint8_t)ret;
+
+       return 0;
+}
+
I personally would prefer if you would retain the original API, which returns 
both value
and error code as return value. I don't see the benefit of changing the API as 
you did -
it just complicates the code.

Thanks,
Guenter

I think it is ok for a wrapper like this because it does not really change an 
API because
it is menf21bmc related.

I did the same in rtc-rx8581, and it was already done in rtc_ds1307.c.

I personally prefer this way because the return of the function and the return
value of the i2c_smbus_read - which is the value read from the device - are 
seperated.

If it is a no go for the mfd/wdt core i can change it back to the original 
i2c_smbus API.
If it is ok on your side for a wrapper like this, we can let it as it is.


Not my call to make; depends on the mfd maintainer. I would not accept it, as I 
see it
as unnecessary, adding complexity, and pointless. Sure, you can always find 
examples
for everything somewhere in the kernel, but that doesn't make it better.

Guenter

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to