hwmon: (pmbus) Add support for TI UCD9200 series of PWM System Controllers

Kernel driver ucd9200

=====================

Supported chips:

  * TI UCD9220, UCD9222, UCD9224, UCD9240, UCD9244, UCD9246, and UCD9248

    Prefixes: 'ucd9220', 'ucd9222', 'ucd9224', 'ucd9240', 'ucd9244', 'ucd9246',

	'ucd9248'

    Addresses scanned: -

    Datasheets:

	http://focus.ti.com/lit/ds/symlink/ucd9220.pdf

	http://focus.ti.com/lit/ds/symlink/ucd9222.pdf

	http://focus.ti.com/lit/ds/symlink/ucd9224.pdf

	http://focus.ti.com/lit/ds/symlink/ucd9240.pdf

	http://focus.ti.com/lit/ds/symlink/ucd9244.pdf

	http://focus.ti.com/lit/ds/symlink/ucd9246.pdf

	http://focus.ti.com/lit/ds/symlink/ucd9248.pdf

Author: Guenter Roeck <guenter.roeck@ericsson.com>

Description

-----------

[From datasheets] UCD9220, UCD9222, UCD9224, UCD9240, UCD9244, UCD9246, and

UCD9248 are multi-rail, multi-phase synchronous buck digital PWM controllers

designed for non-isolated DC/DC power applications. The devices integrate

dedicated circuitry for DC/DC loop management with flash memory and a serial

interface to support configuration, monitoring and management.

This driver is a client driver to the core PMBus driver. Please see

Documentation/hwmon/pmbus for details on PMBus client drivers.

Usage Notes

-----------

This driver does not auto-detect devices. You will have to instantiate the

devices explicitly. Please see Documentation/i2c/instantiating-devices for

details.

Platform data support

---------------------

The driver supports standard PMBus driver platform data. Please see

Documentation/hwmon/pmbus for details.

Sysfs entries

-------------

The following attributes are supported. Limits are read-write; all other

attributes are read-only.

in1_label		"vin".

in1_input		Measured voltage. From READ_VIN register.

in1_min			Minumum Voltage. From VIN_UV_WARN_LIMIT register.

in1_max			Maximum voltage. From VIN_OV_WARN_LIMIT register.

in1_lcrit		Critical minumum Voltage. VIN_UV_FAULT_LIMIT register.

in1_crit		Critical maximum voltage. From VIN_OV_FAULT_LIMIT register.

in1_min_alarm		Voltage low alarm. From VIN_UV_WARNING status.

in1_max_alarm		Voltage high alarm. From VIN_OV_WARNING status.

in1_lcrit_alarm		Voltage critical low alarm. From VIN_UV_FAULT status.

in1_crit_alarm		Voltage critical high alarm. From VIN_OV_FAULT status.

in[2-5]_label		"vout[1-4]".

in[2-5]_input		Measured voltage. From READ_VOUT register.

in[2-5]_min		Minumum Voltage. From VOUT_UV_WARN_LIMIT register.

in[2-5]_max		Maximum voltage. From VOUT_OV_WARN_LIMIT register.

in[2-5]_lcrit		Critical minumum Voltage. VOUT_UV_FAULT_LIMIT register.

in[2-5]_crit		Critical maximum voltage. From VOUT_OV_FAULT_LIMIT register.

in[2-5]_min_alarm	Voltage low alarm. From VOLTAGE_UV_WARNING status.

in[2-5]_max_alarm	Voltage high alarm. From VOLTAGE_OV_WARNING status.

in[2-5]_lcrit_alarm	Voltage critical low alarm. From VOLTAGE_UV_FAULT status.

in[2-5]_crit_alarm	Voltage critical high alarm. From VOLTAGE_OV_FAULT status.

curr1_label		"iin".

curr1_input		Measured current. From READ_IIN register.

curr[2-5]_label		"iout[1-4]".

curr[2-5]_input		Measured current. From READ_IOUT register.

curr[2-5]_max		Maximum current. From IOUT_OC_WARN_LIMIT register.

curr[2-5]_lcrit		Critical minumum output current. From IOUT_UC_FAULT_LIMIT

			register.

curr[2-5]_crit		Critical maximum current. From IOUT_OC_FAULT_LIMIT register.

curr[2-5]_max_alarm	Current high alarm. From IOUT_OC_WARNING status.

curr[2-5]_crit_alarm	Current critical high alarm. From IOUT_OC_FAULT status.

power1_input		Measured input power. From READ_PIN register.

power1_label		"pin"

power[2-5]_input	Measured output power. From READ_POUT register.

power[2-5]_label	"pout[1-4]"

			The number of output voltage, current, and power

			attribute sets is determined by the number of enabled

			rails. See chip datasheets for details.

temp[1-5]_input		Measured temperatures. From READ_TEMPERATURE_1 and

		        READ_TEMPERATURE_2 registers.

			temp1 is the chip internal temperature. temp[2-5] are

			rail temperatures.  temp[2-5] attributes are only

			created for enabled rails. See chip datasheets for

			details.

temp[1-5]_max		Maximum temperature. From OT_WARN_LIMIT register.

temp[1-5]_crit		Critical high temperature. From OT_FAULT_LIMIT register.

temp[1-5]_max_alarm	Temperature high alarm.

temp[1-5]_crit_alarm	Temperature critical high alarm.

fan1_input		Fan RPM. ucd9240 only.

fan1_alarm		Fan alarm. ucd9240 only.

fan1_fault		Fan fault. ucd9240 only.

	  This driver can also be built as a module. If so, the module will

	  be called max8688.

config SENSORS_UCD9200

	tristate "TI UCD9220, UCD9222, UCD9224, UCD9240, UCD9244, UCD9246, UCD9248"

	default n

	help

	  If you say yes here you get hardware monitoring support for TI

	  UCD9220, UCD9222, UCD9224, UCD9240, UCD9244, UCD9246, and UCD9248.

	  This driver can also be built as a module. If so, the module will

	  be called ucd9200.

endif # PMBUS

config SENSORS_SHT15

obj-$(CONFIG_SENSORS_MAX16064)	+= max16064.o

obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o

obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o

obj-$(CONFIG_SENSORS_UCD9200)	+= ucd9200.o

ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG

/*

 * Hardware monitoring driver for ucd9200 series Digital PWM System Controllers

 *

 * Copyright (C) 2011 Ericsson AB.

 *

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/err.h>

#include <linux/slab.h>

#include <linux/i2c.h>

#include <linux/i2c/pmbus.h>

#include "pmbus.h"

#define UCD9200_PHASE_INFO	0xd2

#define UCD9200_DEVICE_ID	0xfd

enum chips { ucd9200, ucd9220, ucd9222, ucd9224, ucd9240, ucd9244, ucd9246,

	     ucd9248 };

static const struct i2c_device_id ucd9200_id[] = {

	{"ucd9200", ucd9200},

	{"ucd9220", ucd9220},

	{"ucd9222", ucd9222},

	{"ucd9224", ucd9224},

	{"ucd9240", ucd9240},

	{"ucd9244", ucd9244},

	{"ucd9246", ucd9246},

	{"ucd9248", ucd9248},

	{}

};

MODULE_DEVICE_TABLE(i2c, ucd9200_id);

static int ucd9200_probe(struct i2c_client *client,

			 const struct i2c_device_id *id)

{

	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];

	struct pmbus_driver_info *info;

	const struct i2c_device_id *mid;

	int i, j, ret;

	if (!i2c_check_functionality(client->adapter,

				     I2C_FUNC_SMBUS_BYTE_DATA |

				     I2C_FUNC_SMBUS_BLOCK_DATA))

		return -ENODEV;

	ret = i2c_smbus_read_block_data(client, UCD9200_DEVICE_ID,

					block_buffer);

	if (ret < 0) {

		dev_err(&client->dev, "Failed to read device ID\n");

		return ret;

	}

	block_buffer[ret] = '\0';

	dev_info(&client->dev, "Device ID %s\n", block_buffer);

	mid = NULL;

	for (i = 0; i < ARRAY_SIZE(ucd9200_id); i++) {

		mid = &ucd9200_id[i];

		if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))

			break;

	}

	if (!mid || !strlen(mid->name)) {

		dev_err(&client->dev, "Unsupported device\n");

		return -ENODEV;

	}

	if (id->driver_data != ucd9200 && id->driver_data != mid->driver_data)

		dev_notice(&client->dev,

			   "Device mismatch: Configured %s, detected %s\n",

			   id->name, mid->name);

	info = kzalloc(sizeof(struct pmbus_driver_info), GFP_KERNEL);

	if (!info)

		return -ENOMEM;

	ret = i2c_smbus_read_block_data(client, UCD9200_PHASE_INFO,

					block_buffer);

	if (ret < 0) {

		dev_err(&client->dev, "Failed to read phase information\n");

		goto out;

	}

	/*

	 * Calculate number of configured pages (rails) from PHASE_INFO

	 * register.

	 * Rails have to be sequential, so we can abort after finding

	 * the first unconfigured rail.

	 */

	info->pages = 0;

	for (i = 0; i < ret; i++) {

		if (!block_buffer[i])

			break;

		info->pages++;

	}

	if (!info->pages) {

		dev_err(&client->dev, "No rails configured\n");

		ret = -ENODEV;

		goto out;

	}

	dev_info(&client->dev, "%d rails configured\n", info->pages);

	/*

	 * Set PHASE registers on all pages to 0xff to ensure that phase

	 * specific commands will apply to all phases of a given page (rail).

	 * This only affects the READ_IOUT and READ_TEMPERATURE2 registers.

	 * READ_IOUT will return the sum of currents of all phases of a rail,

	 * and READ_TEMPERATURE2 will return the maximum temperature detected

	 * for the the phases of the rail.

	 */

	for (i = 0; i < info->pages; i++) {

		/*

		 * Setting PAGE & PHASE fails once in a while for no obvious

		 * reason, so we need to retry a couple of times.

		 */

		for (j = 0; j < 3; j++) {

			ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);

			if (ret < 0)

				continue;

			ret = i2c_smbus_write_byte_data(client, PMBUS_PHASE,

							0xff);

			if (ret < 0)

				continue;

			break;

		}

		if (ret < 0) {

			dev_err(&client->dev,

				"Failed to initialize PHASE registers\n");

			goto out;

		}

	}

	if (info->pages > 1)

		i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);

	info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |

			PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |

			PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |

			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |

			PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP |

			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;

	for (i = 1; i < info->pages; i++)

		info->func[i] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |

			PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |

			PMBUS_HAVE_POUT |

			PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;

	/* ucd9240 supports a single fan */

	if (mid->driver_data == ucd9240)

		info->func[0] |= PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12;

	ret = pmbus_do_probe(client, mid, info);

	if (ret < 0)

		goto out;

	return 0;

out:

	kfree(info);

	return ret;

}

static int ucd9200_remove(struct i2c_client *client)

{

	int ret;

	const struct pmbus_driver_info *info;

	info = pmbus_get_driver_info(client);

	ret = pmbus_do_remove(client);

	kfree(info);

	return ret;

}

/* This is the driver that will be inserted */

static struct i2c_driver ucd9200_driver = {

	.driver = {

		.name = "ucd9200",

	},

	.probe = ucd9200_probe,

	.remove = ucd9200_remove,

	.id_table = ucd9200_id,

};

static int __init ucd9200_init(void)

{

	return i2c_add_driver(&ucd9200_driver);

}

static void __exit ucd9200_exit(void)

{

	i2c_del_driver(&ucd9200_driver);

}

MODULE_AUTHOR("Guenter Roeck");

MODULE_DESCRIPTION("PMBus driver for TI UCD922x, UCD924x");

MODULE_LICENSE("GPL");

module_init(ucd9200_init);

module_exit(ucd9200_exit);