[PATCH v6 1/4] drivers/mfd/menf21bmc: introduce MEN 14F021P00 BMC MFD Core driver

Andreas Werner
2014-08-27T17:51:45Z

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@men.de>
---
drivers/mfd/Kconfig | 15 ++++++
drivers/mfd/Makefile | 1 +
drivers/mfd/menf21bmc.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 148 insertions(+)
create mode 100644 drivers/mfd/menf21bmc.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b8d9ca0..1020725 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -453,6 +453,21 @@ 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.
+ This driver provides common support for accessing the devices;
+ additional drivers must be enabled in order to use the
+ functionality of the BMC device.
+
+ This driver can also be built as a module. If so the module
+ will be called menf21bmc.
+
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..1c27434
--- /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 rev_major, rev_minor, rev_main;
+ int ret;
+
+ 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);
+
+ /*
+ * 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);
+ 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" },
+ { }
+};
+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,
+};
+
+module_i2c_driver(menf21bmc_driver);
+
+MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");
+MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
+MODULE_LICENSE("GPL v2");
--
2.0.4