drivers/hwmon/pmbus/mp2891.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers(MP2891)
  */

 #include <linux/bitfield.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include "pmbus.h"

 /*
  * Vender specific registers, the register MFR_SVI3_IOUT_PRT(0x65),
  * MFR_VOUT_LOOP_CTRL(0xBD), READ_PIN_EST(0x94)and READ_IIN_EST(0x95)
  * redefine the standard PMBUS register. The MFR_SVI3_IOUT_PRT(0x65)
  * is used to identify the iout scale and the MFR_VOUT_LOOP_CTRL(0xBD)
  * is used to identify the vout scale. The READ_PIN_EST(0x94) is used
  * to read input power per rail. The MP2891 does not have standard
  * READ_IIN register(0x89), the iin telemetry can be obtained through
  * the vendor redefined register READ_IIN_EST(0x95).
  */
 #define MFR_VOUT_LOOP_CTRL	0xBD
 #define READ_PIN_EST	0x94
 #define READ_IIN_EST	0x95
 #define MFR_SVI3_IOUT_PRT	0x65

 #define MP2891_TEMP_LIMIT_OFFSET	40
 #define MP2891_PIN_LIMIT_UINT	2
 #define MP2891_IOUT_LIMIT_UINT	8
 #define MP2891_IOUT_SCALE_DIV	32
 #define MP2891_VOUT_SCALE_DIV	100
 #define MP2891_OVUV_DELTA_SCALE	50
 #define MP2891_OV_LIMIT_SCALE	20
 #define MP2891_UV_LIMIT_SCALE	5

 #define MP2891_PAGE_NUM	2

 #define MP2891_RAIL1_FUNC	(PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | \
 							PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP | \
 							PMBUS_HAVE_POUT | PMBUS_HAVE_PIN | \
 							PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_VOUT | \
 							PMBUS_HAVE_STATUS_IOUT | \
 							PMBUS_HAVE_STATUS_INPUT | \
 							PMBUS_HAVE_STATUS_TEMP)

 #define MP2891_RAIL2_FUNC	(PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | \
 							PMBUS_HAVE_TEMP | PMBUS_HAVE_POUT | \
 							PMBUS_HAVE_PIN | PMBUS_HAVE_IIN | \
 							PMBUS_HAVE_STATUS_VOUT | \
 							PMBUS_HAVE_STATUS_IOUT | \
 							PMBUS_HAVE_STATUS_INPUT | \
 							PMBUS_HAVE_STATUS_TEMP)

 struct mp2891_data {
 	struct pmbus_driver_info info;
 	int vout_scale[MP2891_PAGE_NUM];
 	int iout_scale[MP2891_PAGE_NUM];
 };

 #define to_mp2891_data(x) container_of(x, struct mp2891_data, info)

 /* Converts a LINEAR11 value to DIRECT format */
 static u16 mp2891_reg2data_linear11(u16 word)
 {
 	s16 exponent;
 	s32 mantissa;
 	s64 val;

 	exponent = ((s16)word) >> 11;
 	mantissa = ((s16)((word & 0x7ff) << 5)) >> 5;
 	val = mantissa;

 	if (exponent >= 0)
 		val <<= exponent;
 	else
 		val >>= -exponent;

 	return val;
 }

 static int
 mp2891_identify_vout_scale(struct i2c_client *client, struct pmbus_driver_info *info,
 			   int page)
 {
 	struct mp2891_data *data = to_mp2891_data(info);
 	int ret;

 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
 	if (ret < 0)
 		return ret;

 	ret = i2c_smbus_read_word_data(client, MFR_VOUT_LOOP_CTRL);
 	if (ret < 0)
 		return ret;

 	/*
 	 * The output voltage is equal to the READ_VOUT(0x8B) register value multiplied
 	 * by vout_scale.
 	 * Obtain vout scale from the register MFR_VOUT_LOOP_CTRL, bits 15-14,bit 13.
 	 * If MFR_VOUT_LOOP_CTRL[13] = 1, the vout scale is below:
 	 * 2.5mV/LSB
 	 * If MFR_VOUT_LOOP_CTRL[13] = 0, the vout scale is decided by
 	 * MFR_VOUT_LOOP_CTRL[15:14]:
 	 * 00b - 6.25mV/LSB, 01b - 5mV/LSB, 10b - 2mV/LSB, 11b - 1mV
 	 */
 	if (ret & GENMASK(13, 13)) {
 		data->vout_scale[page] = 250;
 	} else {
 		ret = FIELD_GET(GENMASK(15, 14), ret);
 		if (ret == 0)
 			data->vout_scale[page] = 625;
 		else if (ret == 1)
 			data->vout_scale[page] = 500;
 		else if (ret == 2)
 			data->vout_scale[page] = 200;
 		else
 			data->vout_scale[page] = 100;
 	}

 	return 0;
 }

 static int
 mp2891_identify_iout_scale(struct i2c_client *client, struct pmbus_driver_info *info,
 			   int page)
 {
 	struct mp2891_data *data = to_mp2891_data(info);
 	int ret;

 	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
 	if (ret < 0)
 		return ret;

 	ret = i2c_smbus_read_word_data(client, MFR_SVI3_IOUT_PRT);
 	if (ret < 0)
 		return ret;

 	/*
 	 * The output current is equal to the READ_IOUT(0x8C) register value
 	 * multiplied by iout_scale.
 	 * Obtain iout_scale from the register MFR_SVI3_IOUT_PRT[2:0].
 	 * The value is selected as below:
 	 * 000b - 1A/LSB, 001b - (1/32)A/LSB, 010b - (1/16)A/LSB,
 	 * 011b - (1/8)A/LSB, 100b - (1/4)A/LSB, 101b - (1/2)A/LSB
 	 * 110b - 1A/LSB, 111b - 2A/LSB
 	 */
 	switch (ret & GENMASK(2, 0)) {
 	case 0:
 	case 6:
 		data->iout_scale[page] = 32;
 		break;
 	case 1:
 		data->iout_scale[page] = 1;
 		break;
 	case 2:
 		data->iout_scale[page] = 2;
 		break;
 	case 3:
 		data->iout_scale[page] = 4;
 		break;
 	case 4:
 		data->iout_scale[page] = 8;
 		break;
 	case 5:
 		data->iout_scale[page] = 16;
 		break;
 	default:
 		data->iout_scale[page] = 64;
 		break;
 	}

 	return 0;
 }

 static int mp2891_identify(struct i2c_client *client, struct pmbus_driver_info *info)
 {
 	int ret;

 	/* Identify vout scale for rail 1. */
 	ret = mp2891_identify_vout_scale(client, info, 0);
 	if (ret < 0)
 		return ret;

 	/* Identify vout scale for rail 2. */
 	ret = mp2891_identify_vout_scale(client, info, 1);
 	if (ret < 0)
 		return ret;

 	/* Identify iout scale for rail 1. */
 	ret = mp2891_identify_iout_scale(client, info, 0);
 	if (ret < 0)
 		return ret;

 	/* Identify iout scale for rail 2. */
 	return mp2891_identify_iout_scale(client, info, 1);
 }

 static int mp2891_read_byte_data(struct i2c_client *client, int page, int reg)
 {
 	int ret;

 	switch (reg) {
 	case PMBUS_VOUT_MODE:
 		/*
 		 * The MP2891 does not follow standard PMBus protocol completely, the
 		 * PMBUS_VOUT_MODE(0x20) in MP2891 is reserved and 0x00 is always
 		 * returned when the register is read. But the calculation of vout in
 		 * this driver is based on direct format. As a result, the format of
 		 * vout is enforced to direct.
 		 */
 		ret = PB_VOUT_MODE_DIRECT;
 		break;
 	default:
 		ret = -ENODATA;
 		break;
 	}

 	return ret;
 }

 static int mp2891_read_word_data(struct i2c_client *client, int page,
 				 int phase, int reg)
 {
 	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 	struct mp2891_data *data = to_mp2891_data(info);
 	int ret;

 	switch (reg) {
 	case PMBUS_READ_VIN:
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = ret & GENMASK(9, 0);
 		break;
 	case PMBUS_READ_IIN:
 		/*
 		 * The MP2891 does not have standard PMBUS_READ_IIN register(0x89),
 		 * the iin telemetry can be obtained through the vender redefined
 		 * register READ_IIN_EST(0x95). The MP2891 PMBUS_READ_IIN register
 		 * is linear11 format, But the pout scale is set to 1A/Lsb(using
 		 * r/m/b scale). As a result, the iin read from MP2891 should be
 		 * calculated to A, then return the result to pmbus core.
 		 */
 		ret = pmbus_read_word_data(client, page, phase, READ_IIN_EST);
 		if (ret < 0)
 			return ret;

 		ret = mp2891_reg2data_linear11(ret);
 		break;
 	case PMBUS_READ_PIN:
 		/*
 		 * The MP2891 has standard PMBUS_READ_PIN register(0x97), but this
 		 * is not used to read the input power per rail. The input power
 		 * per rail is read through the vender redefined register
 		 * READ_PIN_EST(0x94). The MP2891 PMBUS_READ_PIN register is linear11
 		 * format, But the pout scale is set to 1W/Lsb(using r/m/b scale).
 		 * As a result, the pin read from MP2891 should be calculated to W,
 		 * then return the result to pmbus core.
 		 */
 		ret = pmbus_read_word_data(client, page, phase, READ_PIN_EST);
 		if (ret < 0)
 			return ret;

 		ret = mp2891_reg2data_linear11(ret);
 		break;
 	case PMBUS_READ_POUT:
 		/*
 		 * The MP2891 PMBUS_READ_POUT register is linear11 format, and the
 		 * exponent is not a constant value. But the pout scale is set to
 		 * 1W/Lsb(using r/m/b scale). As a result, the pout read from MP2891
 		 * should be calculated to W, then return the result to pmbus core.
 		 */
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = mp2891_reg2data_linear11(ret);
 		break;
 	case PMBUS_READ_VOUT:
 	case PMBUS_VOUT_UV_WARN_LIMIT:
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = DIV_ROUND_CLOSEST(ret * data->vout_scale[page], MP2891_VOUT_SCALE_DIV);
 		break;
 	case PMBUS_READ_IOUT:
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = DIV_ROUND_CLOSEST((ret & GENMASK(10, 0)) * data->iout_scale[page],
 					MP2891_IOUT_SCALE_DIV);
 		break;
 	case PMBUS_OT_FAULT_LIMIT:
 	case PMBUS_OT_WARN_LIMIT:
 		/*
 		 * The scale of MP2891 PMBUS_OT_FAULT_LIMIT and PMBUS_OT_WARN_LIMIT
 		 * is 1°C/LSB and they have 40°C offset.
 		 */
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = (ret & GENMASK(7, 0)) - MP2891_TEMP_LIMIT_OFFSET;
 		break;
 	case PMBUS_VIN_OV_FAULT_LIMIT:
 		/*
 		 * The MP2891 PMBUS_VIN_OV_FAULT_LIMIT scale is 125mV/Lsb.
 		 * but the vin scale is set to 31.25mV/Lsb(using r/m/b scale).
 		 * As a result, the limit value should be multiplied by 4.
 		 */
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = (ret & GENMASK(7, 0)) * 4;
 		break;
 	case PMBUS_VOUT_UV_FAULT_LIMIT:
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		if (FIELD_GET(GENMASK(11, 8), ret))
 			ret = FIELD_GET(GENMASK(7, 0), ret) * MP2891_UV_LIMIT_SCALE -
 				(FIELD_GET(GENMASK(11, 8), ret) + 1) * MP2891_OVUV_DELTA_SCALE;
 		else
 			ret = FIELD_GET(GENMASK(7, 0), ret) * MP2891_UV_LIMIT_SCALE;

 		ret = ret < 0 ? 0 : ret;
 		break;
 	case PMBUS_VOUT_OV_FAULT_LIMIT:
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		if (FIELD_GET(GENMASK(11, 8), ret))
 			ret = FIELD_GET(GENMASK(7, 0), ret) * MP2891_OV_LIMIT_SCALE +
 				(FIELD_GET(GENMASK(11, 8), ret) + 1) * MP2891_OVUV_DELTA_SCALE;
 		else
 			ret = FIELD_GET(GENMASK(7, 0), ret) * MP2891_OV_LIMIT_SCALE;
 		break;
 	case PMBUS_IOUT_OC_WARN_LIMIT:
 	case PMBUS_IOUT_OC_FAULT_LIMIT:
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = DIV_ROUND_CLOSEST((ret & GENMASK(7, 0)) * data->iout_scale[page] *
 						MP2891_IOUT_LIMIT_UINT, MP2891_IOUT_SCALE_DIV);
 		break;
 	case PMBUS_IIN_OC_WARN_LIMIT:
 		/*
 		 * The scale of PMBUS_IIN_OC_WARN_LIMIT is 0.5A/Lsb, but the iin scale
 		 * is set to 1A/Lsb(using r/m/b scale), so the word data should be
 		 * divided by 2.
 		 */
 		ret = pmbus_read_word_data(client, 0, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = DIV_ROUND_CLOSEST((ret & GENMASK(9, 0)), 2);
 		break;
 	case PMBUS_PIN_OP_WARN_LIMIT:
 		/*
 		 * The scale of PMBUS_PIN_OP_WARN_LIMIT is 2W/Lsb, but the pin scale
 		 * is set to 1W/Lsb(using r/m/b scale), so the word data should be
 		 * multiplied by 2.
 		 */
 		ret = pmbus_read_word_data(client, 0, phase, reg);
 		if (ret < 0)
 			return ret;

 		ret = (ret & GENMASK(9, 0)) * MP2891_PIN_LIMIT_UINT;
 		break;
 	case PMBUS_READ_TEMPERATURE_1:
 	case PMBUS_VIN_UV_FAULT_LIMIT:
 	case PMBUS_VIN_UV_WARN_LIMIT:
 		ret = -ENODATA;
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	return ret;
 }

 static int mp2891_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 mp2891_data *data = to_mp2891_data(info);
 	int ret;

 	switch (reg) {
 	case PMBUS_VOUT_UV_WARN_LIMIT:
 		ret = pmbus_write_word_data(client, page, reg,
 					    DIV_ROUND_CLOSEST(word * MP2891_VOUT_SCALE_DIV,
 							      data->vout_scale[page]));
 		break;
 	case PMBUS_VOUT_UV_FAULT_LIMIT:
 		/*
 		 * The PMBUS_VOUT_UV_FAULT_LIMIT[7:0] is the limit value, and bit8-bit15
 		 * should not be changed.
 		 */
 		ret = pmbus_read_word_data(client, page, 0xff, reg);
 		if (ret < 0)
 			return ret;

 		if (FIELD_GET(GENMASK(11, 8), ret))
 			ret = pmbus_write_word_data(client, page, reg,
 						    (ret & ~GENMASK(7, 0)) |
 							FIELD_PREP(GENMASK(7, 0),
 								   DIV_ROUND_CLOSEST(word +
 							(FIELD_GET(GENMASK(11, 8), ret) + 1) *
 								MP2891_OVUV_DELTA_SCALE,
 								MP2891_UV_LIMIT_SCALE)));
 		else
 			ret = pmbus_write_word_data(client, page, reg,
 						    (ret & ~GENMASK(7, 0)) |
 					FIELD_PREP(GENMASK(7, 0),
 						   DIV_ROUND_CLOSEST(word,
 								     MP2891_UV_LIMIT_SCALE)));
 		break;
 	case PMBUS_VOUT_OV_FAULT_LIMIT:
 		/*
 		 * The PMBUS_VOUT_OV_FAULT_LIMIT[7:0] is the limit value, and bit8-bit15
 		 * should not be changed.
 		 */
 		ret = pmbus_read_word_data(client, page, 0xff, reg);
 		if (ret < 0)
 			return ret;

 		if (FIELD_GET(GENMASK(11, 8), ret))
 			ret = pmbus_write_word_data(client, page, reg,
 						    (ret & ~GENMASK(7, 0)) |
 							FIELD_PREP(GENMASK(7, 0),
 								   DIV_ROUND_CLOSEST(word -
 							(FIELD_GET(GENMASK(11, 8), ret) + 1) *
 								MP2891_OVUV_DELTA_SCALE,
 								MP2891_OV_LIMIT_SCALE)));
 		else
 			ret = pmbus_write_word_data(client, page, reg,
 						    (ret & ~GENMASK(7, 0)) |
 					FIELD_PREP(GENMASK(7, 0),
 						   DIV_ROUND_CLOSEST(word,
 								     MP2891_OV_LIMIT_SCALE)));
 		break;
 	case PMBUS_VIN_OV_FAULT_LIMIT:
 		/*
 		 * The PMBUS_VIN_OV_FAULT_LIMIT[7:0] is the limit value, and bit8-bit15
 		 * should not be changed. The scale of PMBUS_VIN_OV_FAULT_LIMIT is 125mV/Lsb,
 		 * but the vin scale is set to 31.25mV/Lsb(using r/m/b scale), so the word data
 		 * should be divided by 4.
 		 */
 		ret = pmbus_read_word_data(client, page, 0xff, reg);
 		if (ret < 0)
 			return ret;

 		ret = pmbus_write_word_data(client, page, reg,
 					    (ret & ~GENMASK(7, 0)) |
 						FIELD_PREP(GENMASK(7, 0),
 							   DIV_ROUND_CLOSEST(word, 4)));
 		break;
 	case PMBUS_OT_FAULT_LIMIT:
 	case PMBUS_OT_WARN_LIMIT:
 		/*
 		 * The scale of MP2891 PMBUS_OT_FAULT_LIMIT and PMBUS_OT_WARN_LIMIT
 		 * have 40°C offset. The bit0-bit7 is the limit value, and bit8-bit15
 		 * should not be changed.
 		 */
 		ret = pmbus_read_word_data(client, page, 0xff, reg);
 		if (ret < 0)
 			return ret;

 		ret = pmbus_write_word_data(client, page, reg,
 					    (ret & ~GENMASK(7, 0)) |
 				FIELD_PREP(GENMASK(7, 0), word + MP2891_TEMP_LIMIT_OFFSET));
 		break;
 	case PMBUS_IOUT_OC_WARN_LIMIT:
 	case PMBUS_IOUT_OC_FAULT_LIMIT:
 		ret = pmbus_write_word_data(client, page, reg,
 					    DIV_ROUND_CLOSEST(word * MP2891_IOUT_SCALE_DIV,
 							      MP2891_IOUT_LIMIT_UINT *
 								  data->iout_scale[page]));
 		break;
 	case PMBUS_IIN_OC_WARN_LIMIT:
 		/*
 		 * The scale of PMBUS_IIN_OC_WARN_LIMIT is 0.5A/Lsb, but the iin scale
 		 * is set to 1A/Lsb(using r/m/b scale), so the word data should be
 		 * multiplied by 2.
 		 */
 		ret = pmbus_write_word_data(client, page, reg, word * 2);
 		break;
 	case PMBUS_PIN_OP_WARN_LIMIT:
 		/*
 		 * The scale of PMBUS_PIN_OP_WARN_LIMIT is 2W/Lsb, but the pin scale
 		 * is set to 1W/Lsb(using r/m/b scale), so the word data should be
 		 * divided by 2.
 		 */
 		ret = pmbus_write_word_data(client, page, reg,
 					    DIV_ROUND_CLOSEST(word, MP2891_PIN_LIMIT_UINT));
 		break;
 	case PMBUS_VIN_UV_FAULT_LIMIT:
 	case PMBUS_VIN_UV_WARN_LIMIT:
 		ret = -ENODATA;
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	return ret;
 }

 static const struct pmbus_driver_info mp2891_info = {
 	.pages = MP2891_PAGE_NUM,
 	.format[PSC_VOLTAGE_IN] = direct,
 	.format[PSC_CURRENT_IN] = direct,
 	.format[PSC_CURRENT_OUT] = direct,
 	.format[PSC_TEMPERATURE] = direct,
 	.format[PSC_POWER] = direct,
 	.format[PSC_VOLTAGE_OUT] = direct,

 	/* set vin scale 31.25mV/Lsb */
 	.m[PSC_VOLTAGE_IN] = 32,
 	.R[PSC_VOLTAGE_IN] = 0,
 	.b[PSC_VOLTAGE_IN] = 0,

 	/* set temp scale 1000m°C/Lsb */
 	.m[PSC_TEMPERATURE] = 1,
 	.R[PSC_TEMPERATURE] = 0,
 	.b[PSC_TEMPERATURE] = 0,

 	.m[PSC_CURRENT_IN] = 1,
 	.R[PSC_CURRENT_IN] = 0,
 	.b[PSC_CURRENT_IN] = 0,

 	.m[PSC_CURRENT_OUT] = 1,
 	.R[PSC_CURRENT_OUT] = 0,
 	.b[PSC_CURRENT_OUT] = 0,

 	.m[PSC_POWER] = 1,
 	.R[PSC_POWER] = 0,
 	.b[PSC_POWER] = 0,

 	.m[PSC_VOLTAGE_OUT] = 1,
 	.R[PSC_VOLTAGE_OUT] = 3,
 	.b[PSC_VOLTAGE_OUT] = 0,

 	.func[0] = MP2891_RAIL1_FUNC,
 	.func[1] = MP2891_RAIL2_FUNC,
 	.read_word_data = mp2891_read_word_data,
 	.write_word_data = mp2891_write_word_data,
 	.read_byte_data = mp2891_read_byte_data,
 	.identify = mp2891_identify,
 };

 static int mp2891_probe(struct i2c_client *client)
 {
 	struct mp2891_data *data;

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

 	memcpy(&data->info, &mp2891_info, sizeof(mp2891_info));

 	return pmbus_do_probe(client, &data->info);
 }

 static const struct i2c_device_id mp2891_id[] = {
 	{"mp2891", 0},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, mp2891_id);

 static const struct of_device_id __maybe_unused mp2891_of_match[] = {
 	{.compatible = "mps,mp2891"},
 	{}
 };
 MODULE_DEVICE_TABLE(of, mp2891_of_match);

 static struct i2c_driver mp2891_driver = {
 	.driver = {
 		.name = "mp2891",
 		.of_match_table = mp2891_of_match,
 	},
 	.probe = mp2891_probe,
 	.id_table = mp2891_id,
 };

 module_i2c_driver(mp2891_driver);

 MODULE_AUTHOR("Noah Wang <noahwang.wang@outlook.com>");
 MODULE_DESCRIPTION("PMBus driver for MPS MP2891");
 MODULE_LICENSE("GPL");
 MODULE_IMPORT_NS(PMBUS);
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Hardware monitoring driver for MPS Multi-phase Digital VR Controllers(MP2891)
	*/

	#include <linux/bitfield.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include "pmbus.h"

	/*
	* Vender specific registers, the register MFR_SVI3_IOUT_PRT(0x65),
	* MFR_VOUT_LOOP_CTRL(0xBD), READ_PIN_EST(0x94)and READ_IIN_EST(0x95)
	* redefine the standard PMBUS register. The MFR_SVI3_IOUT_PRT(0x65)
	* is used to identify the iout scale and the MFR_VOUT_LOOP_CTRL(0xBD)
	* is used to identify the vout scale. The READ_PIN_EST(0x94) is used
	* to read input power per rail. The MP2891 does not have standard
	* READ_IIN register(0x89), the iin telemetry can be obtained through
	* the vendor redefined register READ_IIN_EST(0x95).
	*/
	#define MFR_VOUT_LOOP_CTRL 0xBD
	#define READ_PIN_EST 0x94
	#define READ_IIN_EST 0x95
	#define MFR_SVI3_IOUT_PRT 0x65

	#define MP2891_TEMP_LIMIT_OFFSET 40
	#define MP2891_PIN_LIMIT_UINT 2
	#define MP2891_IOUT_LIMIT_UINT 8
	#define MP2891_IOUT_SCALE_DIV 32
	#define MP2891_VOUT_SCALE_DIV 100
	#define MP2891_OVUV_DELTA_SCALE 50
	#define MP2891_OV_LIMIT_SCALE 20
	#define MP2891_UV_LIMIT_SCALE 5

	#define MP2891_PAGE_NUM 2

	#define MP2891_RAIL1_FUNC (PMBUS_HAVE_VIN \| PMBUS_HAVE_VOUT \| \
	PMBUS_HAVE_IOUT \| PMBUS_HAVE_TEMP \| \
	PMBUS_HAVE_POUT \| PMBUS_HAVE_PIN \| \
	PMBUS_HAVE_IIN \| PMBUS_HAVE_STATUS_VOUT \| \
	PMBUS_HAVE_STATUS_IOUT \| \
	PMBUS_HAVE_STATUS_INPUT \| \
	PMBUS_HAVE_STATUS_TEMP)

	#define MP2891_RAIL2_FUNC (PMBUS_HAVE_VOUT \| PMBUS_HAVE_IOUT \| \
	PMBUS_HAVE_TEMP \| PMBUS_HAVE_POUT \| \
	PMBUS_HAVE_PIN \| PMBUS_HAVE_IIN \| \
	PMBUS_HAVE_STATUS_VOUT \| \
	PMBUS_HAVE_STATUS_IOUT \| \
	PMBUS_HAVE_STATUS_INPUT \| \
	PMBUS_HAVE_STATUS_TEMP)

	struct mp2891_data {
	struct pmbus_driver_info info;
	int vout_scale[MP2891_PAGE_NUM];
	int iout_scale[MP2891_PAGE_NUM];
	};

	#define to_mp2891_data(x) container_of(x, struct mp2891_data, info)

	/* Converts a LINEAR11 value to DIRECT format */
	static u16 mp2891_reg2data_linear11(u16 word)
	{
	s16 exponent;
	s32 mantissa;
	s64 val;

	exponent = ((s16)word) >> 11;
	mantissa = ((s16)((word & 0x7ff) << 5)) >> 5;
	val = mantissa;

	if (exponent >= 0)
	val <<= exponent;
	else
	val >>= -exponent;

	return val;
	}

	static int
	mp2891_identify_vout_scale(struct i2c_client client, struct pmbus_driver_info info,
	int page)
	{
	struct mp2891_data *data = to_mp2891_data(info);
	int ret;

	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
	if (ret < 0)
	return ret;

	ret = i2c_smbus_read_word_data(client, MFR_VOUT_LOOP_CTRL);
	if (ret < 0)
	return ret;

	/*
	* The output voltage is equal to the READ_VOUT(0x8B) register value multiplied
	* by vout_scale.
	* Obtain vout scale from the register MFR_VOUT_LOOP_CTRL, bits 15-14,bit 13.
	* If MFR_VOUT_LOOP_CTRL[13] = 1, the vout scale is below:
	* 2.5mV/LSB
	* If MFR_VOUT_LOOP_CTRL[13] = 0, the vout scale is decided by
	* MFR_VOUT_LOOP_CTRL[15:14]:
	* 00b - 6.25mV/LSB, 01b - 5mV/LSB, 10b - 2mV/LSB, 11b - 1mV
	*/
	if (ret & GENMASK(13, 13)) {
	data->vout_scale[page] = 250;
	} else {
	ret = FIELD_GET(GENMASK(15, 14), ret);
	if (ret == 0)
	data->vout_scale[page] = 625;
	else if (ret == 1)
	data->vout_scale[page] = 500;
	else if (ret == 2)
	data->vout_scale[page] = 200;
	else
	data->vout_scale[page] = 100;
	}

	return 0;
	}

	static int
	mp2891_identify_iout_scale(struct i2c_client client, struct pmbus_driver_info info,
	int page)
	{
	struct mp2891_data *data = to_mp2891_data(info);
	int ret;

	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
	if (ret < 0)
	return ret;

	ret = i2c_smbus_read_word_data(client, MFR_SVI3_IOUT_PRT);
	if (ret < 0)
	return ret;

	/*
	* The output current is equal to the READ_IOUT(0x8C) register value
	* multiplied by iout_scale.
	* Obtain iout_scale from the register MFR_SVI3_IOUT_PRT[2:0].
	* The value is selected as below:
	* 000b - 1A/LSB, 001b - (1/32)A/LSB, 010b - (1/16)A/LSB,
	* 011b - (1/8)A/LSB, 100b - (1/4)A/LSB, 101b - (1/2)A/LSB
	* 110b - 1A/LSB, 111b - 2A/LSB
	*/
	switch (ret & GENMASK(2, 0)) {
	case 0:
	case 6:
	data->iout_scale[page] = 32;
	break;
	case 1:
	data->iout_scale[page] = 1;
	break;
	case 2:
	data->iout_scale[page] = 2;
	break;
	case 3:
	data->iout_scale[page] = 4;
	break;
	case 4:
	data->iout_scale[page] = 8;
	break;
	case 5:
	data->iout_scale[page] = 16;
	break;
	default:
	data->iout_scale[page] = 64;
	break;
	}

	return 0;
	}

	static int mp2891_identify(struct i2c_client client, struct pmbus_driver_info info)
	{
	int ret;

	/* Identify vout scale for rail 1. */
	ret = mp2891_identify_vout_scale(client, info, 0);
	if (ret < 0)
	return ret;

	/* Identify vout scale for rail 2. */
	ret = mp2891_identify_vout_scale(client, info, 1);
	if (ret < 0)
	return ret;

	/* Identify iout scale for rail 1. */
	ret = mp2891_identify_iout_scale(client, info, 0);
	if (ret < 0)
	return ret;

	/* Identify iout scale for rail 2. */
	return mp2891_identify_iout_scale(client, info, 1);
	}

	static int mp2891_read_byte_data(struct i2c_client *client, int page, int reg)
	{
	int ret;

	switch (reg) {
	case PMBUS_VOUT_MODE:
	/*
	* The MP2891 does not follow standard PMBus protocol completely, the
	* PMBUS_VOUT_MODE(0x20) in MP2891 is reserved and 0x00 is always
	* returned when the register is read. But the calculation of vout in
	* this driver is based on direct format. As a result, the format of
	* vout is enforced to direct.
	*/
	ret = PB_VOUT_MODE_DIRECT;
	break;
	default:
	ret = -ENODATA;
	break;
	}

	return ret;
	}

	static int mp2891_read_word_data(struct i2c_client *client, int page,
	int phase, int reg)
	{
	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
	struct mp2891_data *data = to_mp2891_data(info);
	int ret;

	switch (reg) {
	case PMBUS_READ_VIN:
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	ret = ret & GENMASK(9, 0);
	break;
	case PMBUS_READ_IIN:
	/*
	* The MP2891 does not have standard PMBUS_READ_IIN register(0x89),
	* the iin telemetry can be obtained through the vender redefined
	* register READ_IIN_EST(0x95). The MP2891 PMBUS_READ_IIN register
	* is linear11 format, But the pout scale is set to 1A/Lsb(using
	* r/m/b scale). As a result, the iin read from MP2891 should be
	* calculated to A, then return the result to pmbus core.
	*/
	ret = pmbus_read_word_data(client, page, phase, READ_IIN_EST);
	if (ret < 0)
	return ret;

	ret = mp2891_reg2data_linear11(ret);
	break;
	case PMBUS_READ_PIN:
	/*
	* The MP2891 has standard PMBUS_READ_PIN register(0x97), but this
	* is not used to read the input power per rail. The input power
	* per rail is read through the vender redefined register
	* READ_PIN_EST(0x94). The MP2891 PMBUS_READ_PIN register is linear11
	* format, But the pout scale is set to 1W/Lsb(using r/m/b scale).
	* As a result, the pin read from MP2891 should be calculated to W,
	* then return the result to pmbus core.
	*/
	ret = pmbus_read_word_data(client, page, phase, READ_PIN_EST);
	if (ret < 0)
	return ret;

	ret = mp2891_reg2data_linear11(ret);
	break;
	case PMBUS_READ_POUT:
	/*
	* The MP2891 PMBUS_READ_POUT register is linear11 format, and the
	* exponent is not a constant value. But the pout scale is set to
	* 1W/Lsb(using r/m/b scale). As a result, the pout read from MP2891
	* should be calculated to W, then return the result to pmbus core.
	*/
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	ret = mp2891_reg2data_linear11(ret);
	break;
	case PMBUS_READ_VOUT:
	case PMBUS_VOUT_UV_WARN_LIMIT:
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	ret = DIV_ROUND_CLOSEST(ret * data->vout_scale[page], MP2891_VOUT_SCALE_DIV);
	break;
	case PMBUS_READ_IOUT:
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	ret = DIV_ROUND_CLOSEST((ret & GENMASK(10, 0)) * data->iout_scale[page],
	MP2891_IOUT_SCALE_DIV);
	break;
	case PMBUS_OT_FAULT_LIMIT:
	case PMBUS_OT_WARN_LIMIT:
	/*
	* The scale of MP2891 PMBUS_OT_FAULT_LIMIT and PMBUS_OT_WARN_LIMIT
	* is 1°C/LSB and they have 40°C offset.
	*/
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	ret = (ret & GENMASK(7, 0)) - MP2891_TEMP_LIMIT_OFFSET;
	break;
	case PMBUS_VIN_OV_FAULT_LIMIT:
	/*
	* The MP2891 PMBUS_VIN_OV_FAULT_LIMIT scale is 125mV/Lsb.
	* but the vin scale is set to 31.25mV/Lsb(using r/m/b scale).
	* As a result, the limit value should be multiplied by 4.
	*/
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	ret = (ret & GENMASK(7, 0)) * 4;
	break;
	case PMBUS_VOUT_UV_FAULT_LIMIT:
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	if (FIELD_GET(GENMASK(11, 8), ret))
	ret = FIELD_GET(GENMASK(7, 0), ret) * MP2891_UV_LIMIT_SCALE -
	(FIELD_GET(GENMASK(11, 8), ret) + 1) * MP2891_OVUV_DELTA_SCALE;
	else
	ret = FIELD_GET(GENMASK(7, 0), ret) * MP2891_UV_LIMIT_SCALE;

	ret = ret < 0 ? 0 : ret;
	break;
	case PMBUS_VOUT_OV_FAULT_LIMIT:
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	if (FIELD_GET(GENMASK(11, 8), ret))
	ret = FIELD_GET(GENMASK(7, 0), ret) * MP2891_OV_LIMIT_SCALE +
	(FIELD_GET(GENMASK(11, 8), ret) + 1) * MP2891_OVUV_DELTA_SCALE;
	else
	ret = FIELD_GET(GENMASK(7, 0), ret) * MP2891_OV_LIMIT_SCALE;
	break;
	case PMBUS_IOUT_OC_WARN_LIMIT:
	case PMBUS_IOUT_OC_FAULT_LIMIT:
	ret = pmbus_read_word_data(client, page, phase, reg);
	if (ret < 0)
	return ret;

	ret = DIV_ROUND_CLOSEST((ret & GENMASK(7, 0)) * data->iout_scale[page] *
	MP2891_IOUT_LIMIT_UINT, MP2891_IOUT_SCALE_DIV);
	break;
	case PMBUS_IIN_OC_WARN_LIMIT:
	/*
	* The scale of PMBUS_IIN_OC_WARN_LIMIT is 0.5A/Lsb, but the iin scale
	* is set to 1A/Lsb(using r/m/b scale), so the word data should be
	* divided by 2.
	*/
	ret = pmbus_read_word_data(client, 0, phase, reg);
	if (ret < 0)
	return ret;

	ret = DIV_ROUND_CLOSEST((ret & GENMASK(9, 0)), 2);
	break;
	case PMBUS_PIN_OP_WARN_LIMIT:
	/*
	* The scale of PMBUS_PIN_OP_WARN_LIMIT is 2W/Lsb, but the pin scale
	* is set to 1W/Lsb(using r/m/b scale), so the word data should be
	* multiplied by 2.
	*/
	ret = pmbus_read_word_data(client, 0, phase, reg);
	if (ret < 0)
	return ret;

	ret = (ret & GENMASK(9, 0)) * MP2891_PIN_LIMIT_UINT;
	break;
	case PMBUS_READ_TEMPERATURE_1:
	case PMBUS_VIN_UV_FAULT_LIMIT:
	case PMBUS_VIN_UV_WARN_LIMIT:
	ret = -ENODATA;
	break;
	default:
	ret = -EINVAL;
	break;
	}

	return ret;
	}

	static int mp2891_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 mp2891_data *data = to_mp2891_data(info);
	int ret;

	switch (reg) {
	case PMBUS_VOUT_UV_WARN_LIMIT:
	ret = pmbus_write_word_data(client, page, reg,
	DIV_ROUND_CLOSEST(word * MP2891_VOUT_SCALE_DIV,
	data->vout_scale[page]));
	break;
	case PMBUS_VOUT_UV_FAULT_LIMIT:
	/*
	* The PMBUS_VOUT_UV_FAULT_LIMIT[7:0] is the limit value, and bit8-bit15
	* should not be changed.
	*/
	ret = pmbus_read_word_data(client, page, 0xff, reg);
	if (ret < 0)
	return ret;

	if (FIELD_GET(GENMASK(11, 8), ret))
	ret = pmbus_write_word_data(client, page, reg,
	(ret & ~GENMASK(7, 0)) \|
	FIELD_PREP(GENMASK(7, 0),
	DIV_ROUND_CLOSEST(word +
	(FIELD_GET(GENMASK(11, 8), ret) + 1) *
	MP2891_OVUV_DELTA_SCALE,
	MP2891_UV_LIMIT_SCALE)));
	else
	ret = pmbus_write_word_data(client, page, reg,
	(ret & ~GENMASK(7, 0)) \|
	FIELD_PREP(GENMASK(7, 0),
	DIV_ROUND_CLOSEST(word,
	MP2891_UV_LIMIT_SCALE)));
	break;
	case PMBUS_VOUT_OV_FAULT_LIMIT:
	/*
	* The PMBUS_VOUT_OV_FAULT_LIMIT[7:0] is the limit value, and bit8-bit15
	* should not be changed.
	*/
	ret = pmbus_read_word_data(client, page, 0xff, reg);
	if (ret < 0)
	return ret;

	if (FIELD_GET(GENMASK(11, 8), ret))
	ret = pmbus_write_word_data(client, page, reg,
	(ret & ~GENMASK(7, 0)) \|
	FIELD_PREP(GENMASK(7, 0),
	DIV_ROUND_CLOSEST(word -
	(FIELD_GET(GENMASK(11, 8), ret) + 1) *
	MP2891_OVUV_DELTA_SCALE,
	MP2891_OV_LIMIT_SCALE)));
	else
	ret = pmbus_write_word_data(client, page, reg,
	(ret & ~GENMASK(7, 0)) \|
	FIELD_PREP(GENMASK(7, 0),
	DIV_ROUND_CLOSEST(word,
	MP2891_OV_LIMIT_SCALE)));
	break;
	case PMBUS_VIN_OV_FAULT_LIMIT:
	/*
	* The PMBUS_VIN_OV_FAULT_LIMIT[7:0] is the limit value, and bit8-bit15
	* should not be changed. The scale of PMBUS_VIN_OV_FAULT_LIMIT is 125mV/Lsb,
	* but the vin scale is set to 31.25mV/Lsb(using r/m/b scale), so the word data
	* should be divided by 4.
	*/
	ret = pmbus_read_word_data(client, page, 0xff, reg);
	if (ret < 0)
	return ret;

	ret = pmbus_write_word_data(client, page, reg,
	(ret & ~GENMASK(7, 0)) \|
	FIELD_PREP(GENMASK(7, 0),
	DIV_ROUND_CLOSEST(word, 4)));
	break;
	case PMBUS_OT_FAULT_LIMIT:
	case PMBUS_OT_WARN_LIMIT:
	/*
	* The scale of MP2891 PMBUS_OT_FAULT_LIMIT and PMBUS_OT_WARN_LIMIT
	* have 40°C offset. The bit0-bit7 is the limit value, and bit8-bit15
	* should not be changed.
	*/
	ret = pmbus_read_word_data(client, page, 0xff, reg);
	if (ret < 0)
	return ret;

	ret = pmbus_write_word_data(client, page, reg,
	(ret & ~GENMASK(7, 0)) \|
	FIELD_PREP(GENMASK(7, 0), word + MP2891_TEMP_LIMIT_OFFSET));
	break;
	case PMBUS_IOUT_OC_WARN_LIMIT:
	case PMBUS_IOUT_OC_FAULT_LIMIT:
	ret = pmbus_write_word_data(client, page, reg,
	DIV_ROUND_CLOSEST(word * MP2891_IOUT_SCALE_DIV,
	MP2891_IOUT_LIMIT_UINT *
	data->iout_scale[page]));
	break;
	case PMBUS_IIN_OC_WARN_LIMIT:
	/*
	* The scale of PMBUS_IIN_OC_WARN_LIMIT is 0.5A/Lsb, but the iin scale
	* is set to 1A/Lsb(using r/m/b scale), so the word data should be
	* multiplied by 2.
	*/
	ret = pmbus_write_word_data(client, page, reg, word * 2);
	break;
	case PMBUS_PIN_OP_WARN_LIMIT:
	/*
	* The scale of PMBUS_PIN_OP_WARN_LIMIT is 2W/Lsb, but the pin scale
	* is set to 1W/Lsb(using r/m/b scale), so the word data should be
	* divided by 2.
	*/
	ret = pmbus_write_word_data(client, page, reg,
	DIV_ROUND_CLOSEST(word, MP2891_PIN_LIMIT_UINT));
	break;
	case PMBUS_VIN_UV_FAULT_LIMIT:
	case PMBUS_VIN_UV_WARN_LIMIT:
	ret = -ENODATA;
	break;
	default:
	ret = -EINVAL;
	break;
	}

	return ret;
	}

	static const struct pmbus_driver_info mp2891_info = {
	.pages = MP2891_PAGE_NUM,
	.format[PSC_VOLTAGE_IN] = direct,
	.format[PSC_CURRENT_IN] = direct,
	.format[PSC_CURRENT_OUT] = direct,
	.format[PSC_TEMPERATURE] = direct,
	.format[PSC_POWER] = direct,
	.format[PSC_VOLTAGE_OUT] = direct,

	/* set vin scale 31.25mV/Lsb */
	.m[PSC_VOLTAGE_IN] = 32,
	.R[PSC_VOLTAGE_IN] = 0,
	.b[PSC_VOLTAGE_IN] = 0,

	/* set temp scale 1000m°C/Lsb */
	.m[PSC_TEMPERATURE] = 1,
	.R[PSC_TEMPERATURE] = 0,
	.b[PSC_TEMPERATURE] = 0,

	.m[PSC_CURRENT_IN] = 1,
	.R[PSC_CURRENT_IN] = 0,
	.b[PSC_CURRENT_IN] = 0,

	.m[PSC_CURRENT_OUT] = 1,
	.R[PSC_CURRENT_OUT] = 0,
	.b[PSC_CURRENT_OUT] = 0,

	.m[PSC_POWER] = 1,
	.R[PSC_POWER] = 0,
	.b[PSC_POWER] = 0,

	.m[PSC_VOLTAGE_OUT] = 1,
	.R[PSC_VOLTAGE_OUT] = 3,
	.b[PSC_VOLTAGE_OUT] = 0,

	.func[0] = MP2891_RAIL1_FUNC,
	.func[1] = MP2891_RAIL2_FUNC,
	.read_word_data = mp2891_read_word_data,
	.write_word_data = mp2891_write_word_data,
	.read_byte_data = mp2891_read_byte_data,
	.identify = mp2891_identify,
	};

	static int mp2891_probe(struct i2c_client *client)
	{
	struct mp2891_data *data;

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

	memcpy(&data->info, &mp2891_info, sizeof(mp2891_info));

	return pmbus_do_probe(client, &data->info);
	}

	static const struct i2c_device_id mp2891_id[] = {
	{"mp2891", 0},
	{}
	};
	MODULE_DEVICE_TABLE(i2c, mp2891_id);

	static const struct of_device_id __maybe_unused mp2891_of_match[] = {
	{.compatible = "mps,mp2891"},
	{}
	};
	MODULE_DEVICE_TABLE(of, mp2891_of_match);

	static struct i2c_driver mp2891_driver = {
	.driver = {
	.name = "mp2891",
	.of_match_table = mp2891_of_match,
	},
	.probe = mp2891_probe,
	.id_table = mp2891_id,
	};

	module_i2c_driver(mp2891_driver);

	MODULE_AUTHOR("Noah Wang <noahwang.wang@outlook.com>");
	MODULE_DESCRIPTION("PMBus driver for MPS MP2891");
	MODULE_LICENSE("GPL");
	MODULE_IMPORT_NS(PMBUS);