[deliverable/linux.git] / drivers / hwmon / pmbus / ltc2978.c

/*
 * Hardware monitoring driver for LTC2978 and LTC3880
 *
 * 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 "pmbus.h"

enum chips { ltc2978, ltc3880 };

/* LTC2978 and LTC3880 */
#define LTC2978_MFR_VOUT_PEAK		0xdd
#define LTC2978_MFR_VIN_PEAK		0xde
#define LTC2978_MFR_TEMPERATURE_PEAK	0xdf
#define LTC2978_MFR_SPECIAL_ID		0xe7

/* LTC2978 only */
#define LTC2978_MFR_VOUT_MIN		0xfb
#define LTC2978_MFR_VIN_MIN		0xfc
#define LTC2978_MFR_TEMPERATURE_MIN	0xfd

/* LTC3880 only */
#define LTC3880_MFR_IOUT_PEAK		0xd7
#define LTC3880_MFR_CLEAR_PEAKS		0xe3
#define LTC3880_MFR_TEMPERATURE2_PEAK	0xf4

#define LTC2978_ID_REV1			0x0121
#define LTC2978_ID_REV2			0x0122
#define LTC3880_ID			0x4000
#define LTC3880_ID_MASK			0xff00

/*
 * LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which
 * happens pretty much each time chip data is updated. Raw peak data therefore
 * does not provide much value. To be able to provide useful peak data, keep an
 * internal cache of measured peak data, which is only cleared if an explicit
 * "clear peak" command is executed for the sensor in question.
 */
struct ltc2978_data {
	enum chips id;
	int vin_min, vin_max;
	int temp_min, temp_max[2];
	int vout_min[8], vout_max[8];
	int iout_max[2];
	int temp2_max;
	struct pmbus_driver_info info;
};

#define to_ltc2978_data(x)  container_of(x, struct ltc2978_data, info)

static inline int lin11_to_val(int data)
{
	s16 e = ((s16)data) >> 11;
	s32 m = (((s16)(data << 5)) >> 5);

	/*
	 * mantissa is 10 bit + sign, exponent adds up to 15 bit.
	 * Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31).
	 */
	e += 6;
	return (e < 0 ? m >> -e : m << e);
}

static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
					 int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_VIN_MAX:
		ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_PEAK);
		if (ret >= 0) {
			if (lin11_to_val(ret) > lin11_to_val(data->vin_max))
				data->vin_max = ret;
			ret = data->vin_max;
		}
		break;
	case PMBUS_VIRT_READ_VOUT_MAX:
		ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_PEAK);
		if (ret >= 0) {
			/*
			 * VOUT is 16 bit unsigned with fixed exponent,
			 * so we can compare it directly
			 */
			if (ret > data->vout_max[page])
				data->vout_max[page] = ret;
			ret = data->vout_max[page];
		}
		break;
	case PMBUS_VIRT_READ_TEMP_MAX:
		ret = pmbus_read_word_data(client, page,
					   LTC2978_MFR_TEMPERATURE_PEAK);
		if (ret >= 0) {
			if (lin11_to_val(ret)
			    > lin11_to_val(data->temp_max[page]))
				data->temp_max[page] = ret;
			ret = data->temp_max[page];
		}
		break;
	case PMBUS_VIRT_RESET_VOUT_HISTORY:
	case PMBUS_VIRT_RESET_VIN_HISTORY:
	case PMBUS_VIRT_RESET_TEMP_HISTORY:
		ret = 0;
		break;
	default:
		ret = -ENODATA;
		break;
	}
	return ret;
}

static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_VIN_MIN:
		ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_MIN);
		if (ret >= 0) {
			if (lin11_to_val(ret) < lin11_to_val(data->vin_min))
				data->vin_min = ret;
			ret = data->vin_min;
		}
		break;
	case PMBUS_VIRT_READ_VOUT_MIN:
		ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_MIN);
		if (ret >= 0) {
			/*
			 * VOUT_MIN is known to not be supported on some lots
			 * of LTC2978 revision 1, and will return the maximum
			 * possible voltage if read. If VOUT_MAX is valid and
			 * lower than the reading of VOUT_MIN, use it instead.
			 */
			if (data->vout_max[page] && ret > data->vout_max[page])
				ret = data->vout_max[page];
			if (ret < data->vout_min[page])
				data->vout_min[page] = ret;
			ret = data->vout_min[page];
		}
		break;
	case PMBUS_VIRT_READ_TEMP_MIN:
		ret = pmbus_read_word_data(client, page,
					   LTC2978_MFR_TEMPERATURE_MIN);
		if (ret >= 0) {
			if (lin11_to_val(ret)
			    < lin11_to_val(data->temp_min))
				data->temp_min = ret;
			ret = data->temp_min;
		}
		break;
	case PMBUS_VIRT_READ_IOUT_MAX:
	case PMBUS_VIRT_RESET_IOUT_HISTORY:
	case PMBUS_VIRT_READ_TEMP2_MAX:
	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
		ret = -ENXIO;
		break;
	default:
		ret = ltc2978_read_word_data_common(client, page, reg);
		break;
	}
	return ret;
}

static int ltc3880_read_word_data(struct i2c_client *client, int page, int reg)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_READ_IOUT_MAX:
		ret = pmbus_read_word_data(client, page, LTC3880_MFR_IOUT_PEAK);
		if (ret >= 0) {
			if (lin11_to_val(ret)
			    > lin11_to_val(data->iout_max[page]))
				data->iout_max[page] = ret;
			ret = data->iout_max[page];
		}
		break;
	case PMBUS_VIRT_READ_TEMP2_MAX:
		ret = pmbus_read_word_data(client, page,
					   LTC3880_MFR_TEMPERATURE2_PEAK);
		if (ret >= 0) {
			if (lin11_to_val(ret) > lin11_to_val(data->temp2_max))
				data->temp2_max = ret;
			ret = data->temp2_max;
		}
		break;
	case PMBUS_VIRT_READ_VIN_MIN:
	case PMBUS_VIRT_READ_VOUT_MIN:
	case PMBUS_VIRT_READ_TEMP_MIN:
		ret = -ENXIO;
		break;
	case PMBUS_VIRT_RESET_IOUT_HISTORY:
	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
		ret = 0;
		break;
	default:
		ret = ltc2978_read_word_data_common(client, page, reg);
		break;
	}
	return ret;
}

static int ltc2978_clear_peaks(struct i2c_client *client, int page,
			       enum chips id)
{
	int ret;

	if (id == ltc2978)
		ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
	else
		ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);

	return ret;
}

static int ltc2978_write_word_data(struct i2c_client *client, int page,
				    int reg, u16 word)
{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct ltc2978_data *data = to_ltc2978_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VIRT_RESET_IOUT_HISTORY:
		data->iout_max[page] = 0x7c00;
		ret = ltc2978_clear_peaks(client, page, data->id);
		break;
	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
		data->temp2_max = 0x7c00;
		ret = ltc2978_clear_peaks(client, page, data->id);
		break;
	case PMBUS_VIRT_RESET_VOUT_HISTORY:
		data->vout_min[page] = 0xffff;
		data->vout_max[page] = 0;
		ret = ltc2978_clear_peaks(client, page, data->id);
		break;
	case PMBUS_VIRT_RESET_VIN_HISTORY:
		data->vin_min = 0x7bff;
		data->vin_max = 0x7c00;
		ret = ltc2978_clear_peaks(client, page, data->id);
		break;
	case PMBUS_VIRT_RESET_TEMP_HISTORY:
		data->temp_min = 0x7bff;
		data->temp_max[page] = 0x7c00;
		ret = ltc2978_clear_peaks(client, page, data->id);
		break;
	default:
		ret = -ENODATA;
		break;
	}
	return ret;
}

static const struct i2c_device_id ltc2978_id[] = {
	{"ltc2978", ltc2978},
	{"ltc3880", ltc3880},
	{}
};
MODULE_DEVICE_TABLE(i2c, ltc2978_id);

static int ltc2978_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	int chip_id, i;
	struct ltc2978_data *data;
	struct pmbus_driver_info *info;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_READ_WORD_DATA))
		return -ENODEV;

	data = devm_kzalloc(&client->dev, sizeof(struct ltc2978_data),
			    GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
	if (chip_id < 0)
		return chip_id;

	if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2) {
		data->id = ltc2978;
	} else if ((chip_id & LTC3880_ID_MASK) == LTC3880_ID) {
		data->id = ltc3880;
	} else {
		dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
		return -ENODEV;
	}
	if (data->id != id->driver_data)
		dev_warn(&client->dev,
			 "Device mismatch: Configured %s, detected %s\n",
			 id->name,
			 ltc2978_id[data->id].name);

	info = &data->info;
	info->write_word_data = ltc2978_write_word_data;

	data->vin_min = 0x7bff;
	data->vin_max = 0x7c00;
	data->temp_min = 0x7bff;
	for (i = 0; i < ARRAY_SIZE(data->temp_max); i++)
		data->temp_max[i] = 0x7c00;
	data->temp2_max = 0x7c00;

	switch (data->id) {
	case ltc2978:
		info->read_word_data = ltc2978_read_word_data;
		info->pages = 8;
		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
		  | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
		for (i = 1; i < 8; i++) {
			info->func[i] = PMBUS_HAVE_VOUT
			  | PMBUS_HAVE_STATUS_VOUT;
		}
		break;
	case ltc3880:
		info->read_word_data = ltc3880_read_word_data;
		info->pages = 2;
		info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
		  | PMBUS_HAVE_STATUS_INPUT
		  | 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;
		info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
		  | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
		  | PMBUS_HAVE_POUT
		  | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
		data->iout_max[0] = 0x7c00;
		data->iout_max[1] = 0x7c00;
		break;
	default:
		return -ENODEV;
	}
	for (i = 0; i < info->pages; i++)
		data->vout_min[i] = 0xffff;

	return pmbus_do_probe(client, id, info);
}

/* This is the driver that will be inserted */
static struct i2c_driver ltc2978_driver = {
	.driver = {
		   .name = "ltc2978",
		   },
	.probe = ltc2978_probe,
	.remove = pmbus_do_remove,
	.id_table = ltc2978_id,
};

module_i2c_driver(ltc2978_driver);

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for LTC2978 and LTC3880");
MODULE_LICENSE("GPL");
Commit	Line	Data
c3ff9a67	1	/*
ddfb41ca	2	* Hardware monitoring driver for LTC2978 and LTC3880
c3ff9a67 GR	3	*
	4	* Copyright (c) 2011 Ericsson AB.
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*/
	20
	21	#include <linux/kernel.h>
	22	#include <linux/module.h>
	23	#include <linux/init.h>
	24	#include <linux/err.h>
	25	#include <linux/slab.h>
	26	#include <linux/i2c.h>
	27	#include "pmbus.h"
	28
ddfb41ca	29	enum chips { ltc2978, ltc3880 };
c3ff9a67	30
ddfb41ca	31	/* LTC2978 and LTC3880 */
c3ff9a67 GR	32	#define LTC2978_MFR_VOUT_PEAK 0xdd
	33	#define LTC2978_MFR_VIN_PEAK 0xde
	34	#define LTC2978_MFR_TEMPERATURE_PEAK 0xdf
	35	#define LTC2978_MFR_SPECIAL_ID 0xe7
	36
ddfb41ca	37	/* LTC2978 only */
c3ff9a67 GR	38	#define LTC2978_MFR_VOUT_MIN 0xfb
	39	#define LTC2978_MFR_VIN_MIN 0xfc
	40	#define LTC2978_MFR_TEMPERATURE_MIN 0xfd
	41
ddfb41ca GR	42	/* LTC3880 only */
	43	#define LTC3880_MFR_IOUT_PEAK 0xd7
	44	#define LTC3880_MFR_CLEAR_PEAKS 0xe3
	45	#define LTC3880_MFR_TEMPERATURE2_PEAK 0xf4
	46
c3ff9a67 GR	47	#define LTC2978_ID_REV1 0x0121
c3ff9a67 GR	48	#define LTC2978_ID_REV2 0x0122
ddfb41ca GR	49	#define LTC3880_ID 0x4000
ddfb41ca GR	50	#define LTC3880_ID_MASK 0xff00
c3ff9a67 GR	51
	52	/*
	53	* LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which
	54	* happens pretty much each time chip data is updated. Raw peak data therefore
	55	* does not provide much value. To be able to provide useful peak data, keep an
	56	* internal cache of measured peak data, which is only cleared if an explicit
	57	* "clear peak" command is executed for the sensor in question.
	58	*/
	59	struct ltc2978_data {
	60	enum chips id;
	61	int vin_min, vin_max;
8c958c70	62	int temp_min, temp_max[2];
c3ff9a67	63	int vout_min[8], vout_max[8];
ddfb41ca	64	int iout_max[2];
dbd712c2	65	int temp2_max;
c3ff9a67 GR	66	struct pmbus_driver_info info;
	67	};
	68
	69	#define to_ltc2978_data(x) container_of(x, struct ltc2978_data, info)
	70
	71	static inline int lin11_to_val(int data)
	72	{
	73	s16 e = ((s16)data) >> 11;
	74	s32 m = (((s16)(data << 5)) >> 5);
	75
	76	/*
	77	* mantissa is 10 bit + sign, exponent adds up to 15 bit.
	78	* Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31).
	79	*/
	80	e += 6;
	81	return (e < 0 ? m >> -e : m << e);
	82	}
	83
ddfb41ca GR	84	static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
ddfb41ca GR	85	int reg)
c3ff9a67 GR	86	{
	87	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	88	struct ltc2978_data *data = to_ltc2978_data(info);
	89	int ret;
	90
	91	switch (reg) {
	92	case PMBUS_VIRT_READ_VIN_MAX:
	93	ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_PEAK);
	94	if (ret >= 0) {
	95	if (lin11_to_val(ret) > lin11_to_val(data->vin_max))
	96	data->vin_max = ret;
	97	ret = data->vin_max;
	98	}
	99	break;
	100	case PMBUS_VIRT_READ_VOUT_MAX:
	101	ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_PEAK);
	102	if (ret >= 0) {
	103	/*
	104	* VOUT is 16 bit unsigned with fixed exponent,
	105	* so we can compare it directly
	106	*/
	107	if (ret > data->vout_max[page])
	108	data->vout_max[page] = ret;
	109	ret = data->vout_max[page];
	110	}
	111	break;
	112	case PMBUS_VIRT_READ_TEMP_MAX:
	113	ret = pmbus_read_word_data(client, page,
	114	LTC2978_MFR_TEMPERATURE_PEAK);
	115	if (ret >= 0) {
8c958c70 GR	116	if (lin11_to_val(ret)
	117	> lin11_to_val(data->temp_max[page]))
	118	data->temp_max[page] = ret;
	119	ret = data->temp_max[page];
c3ff9a67 GR	120	}
c3ff9a67 GR	121	break;
ddfb41ca GR	122	case PMBUS_VIRT_RESET_VOUT_HISTORY:
	123	case PMBUS_VIRT_RESET_VIN_HISTORY:
	124	case PMBUS_VIRT_RESET_TEMP_HISTORY:
	125	ret = 0;
	126	break;
	127	default:
	128	ret = -ENODATA;
	129	break;
	130	}
	131	return ret;
	132	}
	133
	134	static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
	135	{
	136	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	137	struct ltc2978_data *data = to_ltc2978_data(info);
	138	int ret;
	139
	140	switch (reg) {
c3ff9a67 GR	141	case PMBUS_VIRT_READ_VIN_MIN:
	142	ret = pmbus_read_word_data(client, page, LTC2978_MFR_VIN_MIN);
	143	if (ret >= 0) {
	144	if (lin11_to_val(ret) < lin11_to_val(data->vin_min))
	145	data->vin_min = ret;
	146	ret = data->vin_min;
	147	}
	148	break;
	149	case PMBUS_VIRT_READ_VOUT_MIN:
	150	ret = pmbus_read_word_data(client, page, LTC2978_MFR_VOUT_MIN);
	151	if (ret >= 0) {
	152	/*
	153	* VOUT_MIN is known to not be supported on some lots
	154	* of LTC2978 revision 1, and will return the maximum
	155	* possible voltage if read. If VOUT_MAX is valid and
	156	* lower than the reading of VOUT_MIN, use it instead.
	157	*/
	158	if (data->vout_max[page] && ret > data->vout_max[page])
	159	ret = data->vout_max[page];
	160	if (ret < data->vout_min[page])
	161	data->vout_min[page] = ret;
	162	ret = data->vout_min[page];
	163	}
	164	break;
	165	case PMBUS_VIRT_READ_TEMP_MIN:
	166	ret = pmbus_read_word_data(client, page,
	167	LTC2978_MFR_TEMPERATURE_MIN);
	168	if (ret >= 0) {
	169	if (lin11_to_val(ret)
	170	< lin11_to_val(data->temp_min))
	171	data->temp_min = ret;
	172	ret = data->temp_min;
	173	}
	174	break;
ddfb41ca GR	175	case PMBUS_VIRT_READ_IOUT_MAX:
	176	case PMBUS_VIRT_RESET_IOUT_HISTORY:
	177	case PMBUS_VIRT_READ_TEMP2_MAX:
	178	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
	179	ret = -ENXIO;
	180	break;
	181	default:
	182	ret = ltc2978_read_word_data_common(client, page, reg);
	183	break;
	184	}
	185	return ret;
	186	}
	187
	188	static int ltc3880_read_word_data(struct i2c_client *client, int page, int reg)
	189	{
	190	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	191	struct ltc2978_data *data = to_ltc2978_data(info);
	192	int ret;
	193
	194	switch (reg) {
	195	case PMBUS_VIRT_READ_IOUT_MAX:
	196	ret = pmbus_read_word_data(client, page, LTC3880_MFR_IOUT_PEAK);
	197	if (ret >= 0) {
	198	if (lin11_to_val(ret)
	199	> lin11_to_val(data->iout_max[page]))
	200	data->iout_max[page] = ret;
	201	ret = data->iout_max[page];
	202	}
	203	break;
	204	case PMBUS_VIRT_READ_TEMP2_MAX:
	205	ret = pmbus_read_word_data(client, page,
	206	LTC3880_MFR_TEMPERATURE2_PEAK);
	207	if (ret >= 0) {
dbd712c2 GR	208	if (lin11_to_val(ret) > lin11_to_val(data->temp2_max))
	209	data->temp2_max = ret;
	210	ret = data->temp2_max;
ddfb41ca GR	211	}
	212	break;
	213	case PMBUS_VIRT_READ_VIN_MIN:
	214	case PMBUS_VIRT_READ_VOUT_MIN:
	215	case PMBUS_VIRT_READ_TEMP_MIN:
	216	ret = -ENXIO;
	217	break;
	218	case PMBUS_VIRT_RESET_IOUT_HISTORY:
	219	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
c3ff9a67 GR	220	ret = 0;
	221	break;
	222	default:
ddfb41ca	223	ret = ltc2978_read_word_data_common(client, page, reg);
c3ff9a67 GR	224	break;
	225	}
	226	return ret;
	227	}
	228
ddfb41ca GR	229	static int ltc2978_clear_peaks(struct i2c_client *client, int page,
	230	enum chips id)
	231	{
	232	int ret;
	233
	234	if (id == ltc2978)
	235	ret = pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
	236	else
	237	ret = pmbus_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
	238
	239	return ret;
	240	}
	241
c3ff9a67 GR	242	static int ltc2978_write_word_data(struct i2c_client *client, int page,
	243	int reg, u16 word)
	244	{
	245	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	246	struct ltc2978_data *data = to_ltc2978_data(info);
	247	int ret;
	248
	249	switch (reg) {
ddfb41ca	250	case PMBUS_VIRT_RESET_IOUT_HISTORY:
dbd712c2	251	data->iout_max[page] = 0x7c00;
ddfb41ca GR	252	ret = ltc2978_clear_peaks(client, page, data->id);
	253	break;
	254	case PMBUS_VIRT_RESET_TEMP2_HISTORY:
dbd712c2	255	data->temp2_max = 0x7c00;
ddfb41ca GR	256	ret = ltc2978_clear_peaks(client, page, data->id);
ddfb41ca GR	257	break;
c3ff9a67 GR	258	case PMBUS_VIRT_RESET_VOUT_HISTORY:
	259	data->vout_min[page] = 0xffff;
	260	data->vout_max[page] = 0;
ddfb41ca	261	ret = ltc2978_clear_peaks(client, page, data->id);
c3ff9a67 GR	262	break;
	263	case PMBUS_VIRT_RESET_VIN_HISTORY:
	264	data->vin_min = 0x7bff;
dbd712c2	265	data->vin_max = 0x7c00;
ddfb41ca	266	ret = ltc2978_clear_peaks(client, page, data->id);
c3ff9a67 GR	267	break;
	268	case PMBUS_VIRT_RESET_TEMP_HISTORY:
	269	data->temp_min = 0x7bff;
8c958c70	270	data->temp_max[page] = 0x7c00;
ddfb41ca	271	ret = ltc2978_clear_peaks(client, page, data->id);
c3ff9a67 GR	272	break;
	273	default:
	274	ret = -ENODATA;
	275	break;
	276	}
	277	return ret;
	278	}
	279
	280	static const struct i2c_device_id ltc2978_id[] = {
	281	{"ltc2978", ltc2978},
ddfb41ca	282	{"ltc3880", ltc3880},
c3ff9a67 GR	283	{}
	284	};
	285	MODULE_DEVICE_TABLE(i2c, ltc2978_id);
	286
	287	static int ltc2978_probe(struct i2c_client *client,
	288	const struct i2c_device_id *id)
	289	{
8b313ca7	290	int chip_id, i;
c3ff9a67 GR	291	struct ltc2978_data *data;
	292	struct pmbus_driver_info *info;
	293
	294	if (!i2c_check_functionality(client->adapter,
	295	I2C_FUNC_SMBUS_READ_WORD_DATA))
	296	return -ENODEV;
	297
8b313ca7 GR	298	data = devm_kzalloc(&client->dev, sizeof(struct ltc2978_data),
8b313ca7 GR	299	GFP_KERNEL);
c3ff9a67 GR	300	if (!data)
	301	return -ENOMEM;
	302
	303	chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
8b313ca7 GR	304	if (chip_id < 0)
8b313ca7 GR	305	return chip_id;
c3ff9a67 GR	306
	307	if (chip_id == LTC2978_ID_REV1 \|\| chip_id == LTC2978_ID_REV2) {
	308	data->id = ltc2978;
ddfb41ca GR	309	} else if ((chip_id & LTC3880_ID_MASK) == LTC3880_ID) {
ddfb41ca GR	310	data->id = ltc3880;
c3ff9a67 GR	311	} else {
c3ff9a67 GR	312	dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
8b313ca7	313	return -ENODEV;
c3ff9a67 GR	314	}
	315	if (data->id != id->driver_data)
	316	dev_warn(&client->dev,
	317	"Device mismatch: Configured %s, detected %s\n",
	318	id->name,
	319	ltc2978_id[data->id].name);
	320
	321	info = &data->info;
c3ff9a67 GR	322	info->write_word_data = ltc2978_write_word_data;
c3ff9a67 GR	323
c3ff9a67	324	data->vin_min = 0x7bff;
dbd712c2	325	data->vin_max = 0x7c00;
c3ff9a67	326	data->temp_min = 0x7bff;
8c958c70 GR	327	for (i = 0; i < ARRAY_SIZE(data->temp_max); i++)
8c958c70 GR	328	data->temp_max[i] = 0x7c00;
dbd712c2	329	data->temp2_max = 0x7c00;
c3ff9a67	330
f366fccd	331	switch (data->id) {
c3ff9a67	332	case ltc2978:
ddfb41ca	333	info->read_word_data = ltc2978_read_word_data;
c3ff9a67 GR	334	info->pages = 8;
	335	info->func[0] = PMBUS_HAVE_VIN \| PMBUS_HAVE_STATUS_INPUT
	336	\| PMBUS_HAVE_VOUT \| PMBUS_HAVE_STATUS_VOUT
	337	\| PMBUS_HAVE_TEMP \| PMBUS_HAVE_STATUS_TEMP;
	338	for (i = 1; i < 8; i++) {
	339	info->func[i] = PMBUS_HAVE_VOUT
	340	\| PMBUS_HAVE_STATUS_VOUT;
c3ff9a67 GR	341	}
c3ff9a67 GR	342	break;
ddfb41ca GR	343	case ltc3880:
	344	info->read_word_data = ltc3880_read_word_data;
	345	info->pages = 2;
	346	info->func[0] = PMBUS_HAVE_VIN \| PMBUS_HAVE_IIN
	347	\| PMBUS_HAVE_STATUS_INPUT
	348	\| PMBUS_HAVE_VOUT \| PMBUS_HAVE_STATUS_VOUT
	349	\| PMBUS_HAVE_IOUT \| PMBUS_HAVE_STATUS_IOUT
	350	\| PMBUS_HAVE_POUT \| PMBUS_HAVE_TEMP
	351	\| PMBUS_HAVE_TEMP2 \| PMBUS_HAVE_STATUS_TEMP;
	352	info->func[1] = PMBUS_HAVE_VOUT \| PMBUS_HAVE_STATUS_VOUT
	353	\| PMBUS_HAVE_IOUT \| PMBUS_HAVE_STATUS_IOUT
	354	\| PMBUS_HAVE_POUT
	355	\| PMBUS_HAVE_TEMP \| PMBUS_HAVE_STATUS_TEMP;
dbd712c2 GR	356	data->iout_max[0] = 0x7c00;
dbd712c2 GR	357	data->iout_max[1] = 0x7c00;
ddfb41ca	358	break;
c3ff9a67	359	default:
8b313ca7	360	return -ENODEV;
c3ff9a67	361	}
dbd712c2 GR	362	for (i = 0; i < info->pages; i++)
dbd712c2 GR	363	data->vout_min[i] = 0xffff;
c3ff9a67	364
8b313ca7	365	return pmbus_do_probe(client, id, info);
c3ff9a67 GR	366	}
c3ff9a67 GR	367
c3ff9a67 GR	368	/* This is the driver that will be inserted */
	369	static struct i2c_driver ltc2978_driver = {
	370	.driver = {
	371	.name = "ltc2978",
	372	},
	373	.probe = ltc2978_probe,
dd285ad7	374	.remove = pmbus_do_remove,
c3ff9a67 GR	375	.id_table = ltc2978_id,
	376	};
	377
f0967eea	378	module_i2c_driver(ltc2978_driver);
c3ff9a67 GR	379
c3ff9a67 GR	380	MODULE_AUTHOR("Guenter Roeck");
ddfb41ca	381	MODULE_DESCRIPTION("PMBus driver for LTC2978 and LTC3880");
c3ff9a67	382	MODULE_LICENSE("GPL");