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				https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
				synced 2025-11-04 16:52:06 +10:00 
			
		
		
		
	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> Signed-off-by: Lee Jones <lee.jones@linaro.org>
		
			
				
	
	
		
			133 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			133 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *  MEN 14F021P00 Board Management Controller (BMC) MFD Core Driver.
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 *
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 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH
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 *
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 *  This program is free software; you can redistribute  it and/or modify it
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 *  under  the terms of  the GNU General  Public License as published by the
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 *  Free Software Foundation;  either version 2 of the  License, or (at your
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 *  option) any later version.
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 */
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/mfd/core.h>
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#define BMC_CMD_WDT_EXIT_PROD	0x18
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#define BMC_CMD_WDT_PROD_STAT	0x19
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#define BMC_CMD_REV_MAJOR	0x80
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#define BMC_CMD_REV_MINOR	0x81
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#define BMC_CMD_REV_MAIN	0x82
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static struct mfd_cell menf21bmc_cell[] = {
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	{ .name = "menf21bmc_wdt", },
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	{ .name = "menf21bmc_led", },
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	{ .name = "menf21bmc_hwmon", }
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};
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static int menf21bmc_wdt_exit_prod_mode(struct i2c_client *client)
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{
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	int val, ret;
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	val = i2c_smbus_read_byte_data(client, BMC_CMD_WDT_PROD_STAT);
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	if (val < 0)
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		return val;
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	/*
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	 * Production mode should be not active after delivery of the Board.
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	 * To be sure we check it, inform the user and exit the mode
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	 * if active.
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	 */
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	if (val == 0x00) {
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		dev_info(&client->dev,
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			"BMC in production mode. Exit production mode\n");
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		ret = i2c_smbus_write_byte(client, BMC_CMD_WDT_EXIT_PROD);
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		if (ret < 0)
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			return ret;
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	}
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	return 0;
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}
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static int
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menf21bmc_probe(struct i2c_client *client, const struct i2c_device_id *ids)
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{
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	int rev_major, rev_minor, rev_main;
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	int ret;
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	ret = i2c_check_functionality(client->adapter,
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				      I2C_FUNC_SMBUS_BYTE_DATA |
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				      I2C_FUNC_SMBUS_WORD_DATA |
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				      I2C_FUNC_SMBUS_BYTE);
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	if (!ret)
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		return -ENODEV;
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	rev_major = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAJOR);
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	if (rev_major < 0) {
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		dev_err(&client->dev, "failed to get BMC major revision\n");
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		return rev_major;
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	}
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	rev_minor = i2c_smbus_read_word_data(client, BMC_CMD_REV_MINOR);
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	if (rev_minor < 0) {
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		dev_err(&client->dev, "failed to get BMC minor revision\n");
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		return rev_minor;
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	}
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	rev_main = i2c_smbus_read_word_data(client, BMC_CMD_REV_MAIN);
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	if (rev_main < 0) {
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		dev_err(&client->dev, "failed to get BMC main revision\n");
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		return rev_main;
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	}
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	dev_info(&client->dev, "FW Revision: %02d.%02d.%02d\n",
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		 rev_major, rev_minor, rev_main);
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	/*
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	 * We have to exit the Production Mode of the BMC to activate the
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	 * Watchdog functionality and the BIOS life sign monitoring.
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	 */
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	ret = menf21bmc_wdt_exit_prod_mode(client);
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	if (ret < 0) {
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		dev_err(&client->dev, "failed to leave production mode\n");
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		return ret;
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	}
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	ret = mfd_add_devices(&client->dev, 0, menf21bmc_cell,
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			      ARRAY_SIZE(menf21bmc_cell), NULL, 0, NULL);
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	if (ret < 0) {
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		dev_err(&client->dev, "failed to add BMC sub-devices\n");
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		return ret;
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	}
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	return 0;
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}
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static int menf21bmc_remove(struct i2c_client *client)
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{
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	mfd_remove_devices(&client->dev);
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	return 0;
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}
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static const struct i2c_device_id menf21bmc_id_table[] = {
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	{ "menf21bmc" },
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	{ }
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};
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MODULE_DEVICE_TABLE(i2c, menf21bmc_id_table);
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static struct i2c_driver menf21bmc_driver = {
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	.driver.name	= "menf21bmc",
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	.id_table	= menf21bmc_id_table,
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	.probe		= menf21bmc_probe,
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	.remove		= menf21bmc_remove,
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};
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module_i2c_driver(menf21bmc_driver);
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MODULE_DESCRIPTION("MEN 14F021P00 BMC mfd core driver");
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MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
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MODULE_LICENSE("GPL v2");
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