1 files changed, 121 insertions, 0 deletions
diff --git a/drivers/mfd/menf21bmc.c b/drivers/mfd/menf21bmc.c
new file mode 100644
index 0000000000..1d36095155
--- /dev/null
+++ b/drivers/mfd/menf21bmc.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  MEN 14F021P00 Board Management Controller (BMC) MFD Core Driver.
+ *
+ *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
+ */
+
+#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)
+{
+	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 = devm_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 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,
+};
+
+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");