hwmon: (pmbus) Add support for MPS Multi-phase mp2856/mp2857 controller

   mcp3021

   menf21bmc

   mlxreg-fan

   mp2856

   mp2888

   mp2975

   mp5023

.. SPDX-License-Identifier: GPL-2.0

Kernel driver mp2856

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

Supported chips:

  * MPS MP2856

    Prefix: 'mp2856'

  * MPS MP2857

    Prefix: 'mp2857'

Author:

	Peter Yin <peter.yin@quantatw.com>

Description

-----------

This driver implements support for Monolithic Power Systems, Inc. (MPS)

vendor dual-loop, digital, multi-phase controller MP2856/MP2857

This device:

- Supports up to two power rail.

- Supports two pages 0 and 1 for and also pages 2 for configuration.

- Can configured VOUT readout in direct or VID format and allows

  setting of different formats on rails 1 and 2. For VID the following

  protocols are available: AMD SVI3 mode with 5-mV/LSB.

Device supports:

- SVID interface.

- AVSBus interface.

Device compliant with:

- PMBus rev 1.3 interface.

Device supports direct format for reading output current, output voltage,

input and output power and temperature.

Device supports linear format for reading input voltage and input power.

Device supports VID and direct formats for reading output voltage.

The below VID modes are supported: AMD SVI3.

The driver provides the following sysfs attributes for current measurements:

- indexes 1  for "iin";

- indexes 2, 3 for "iout";

**curr[1-3]_alarm**

**curr[1-3]_input**

**curr[1-3]_label**

The driver provides the following sysfs attributes for voltage measurements.

- indexes 1 for "vin";

- indexes 2, 3 for "vout";

**in[1-3]_crit**

**in[1-3]_crit_alarm**

**in[1-3]_input**

**in[1-3]_label**

**in[1-3]_lcrit**

**in[1-3]_lcrit_alarm**

The driver provides the following sysfs attributes for power measurements.

- indexes 1 for "pin";

- indexes 2, 3 for "pout";

**power[1-3]_alarm**

**power[1-3]_input**

**power[1-3]_label**

The driver provides the following sysfs attributes for temperature measurements.

**temp[1-2]_crit**

**temp[1-2]_crit_alarm**

**temp[1-2]_input**

**temp[1-2]_max**

**temp[1-2]_max_alarm**

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

	  be called max8688.

config SENSORS_MP2856

	tristate "MPS MP2856"

	help

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

	  MP2856 MP2857 Dual Loop Digital Multi-Phase Controller.

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

	  be called mp2856.

config SENSORS_MP2888

	tristate "MPS MP2888"

	help

obj-$(CONFIG_SENSORS_MAX31785)	+= max31785.o

obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o

obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o

obj-$(CONFIG_SENSORS_MP2856)	+= mp2856.o

obj-$(CONFIG_SENSORS_MP2888)	+= mp2888.o

obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o

obj-$(CONFIG_SENSORS_MP5023)	+= mp5023.o

// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * Hardware monitoring driver for MPS2856/2857

 * Monolithic Power Systems VR Controllers

 *

 * Copyright (C) 2023 Quanta Computer lnc.

 */

#include <linux/err.h>

#include <linux/i2c.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/pmbus.h>

#include "pmbus.h"

/* Vendor specific registers. */

#define MP2856_MFR_VR_MULTI_CONFIG_R1	0x0d

#define MP2856_MFR_VR_MULTI_CONFIG_R2	0x1d

#define MP2856_MUL1_BOOT_SR_R2		0x10

#define MP2856_VR_ACTIVE		BIT(15)

#define MP2856_MFR_VR_CONFIG2		0x5e

#define MP2856_VOUT_MODE		BIT(11)

#define MP2856_MFR_VR_CONFIG1		0x68

#define MP2856_DRMOS_KCS		GENMASK(13, 12)

#define MP2856_MFR_READ_CS1_2_R1	0x82

#define MP2856_MFR_READ_CS3_4_R1	0x83

#define MP2856_MFR_READ_CS5_6_R1	0x84

#define MP2856_MFR_READ_CS7_8_R1	0x85

#define MP2856_MFR_READ_CS9_10_R1	0x86

#define MP2856_MFR_READ_CS11_12_R1	0x87

#define MP2856_MFR_READ_CS1_2_R2	0x85

#define MP2856_MFR_READ_CS3_4_R2	0x86

#define MP2856_MFR_READ_CS5_6_R2	0x87

#define MP2856_MAX_PHASE_RAIL1		8

#define MP2856_MAX_PHASE_RAIL2		4

#define MP2857_MAX_PHASE_RAIL1		12

#define MP2857_MAX_PHASE_RAIL2		4

#define MP2856_PAGE_NUM			2

enum chips { mp2856 = 1, mp2857 };

static const int mp2856_max_phases[][MP2856_PAGE_NUM] = {

	[mp2856] = { MP2856_MAX_PHASE_RAIL1, MP2856_MAX_PHASE_RAIL2 },

	[mp2857] = { MP2857_MAX_PHASE_RAIL1, MP2857_MAX_PHASE_RAIL2 },

};

static const struct i2c_device_id mp2856_id[] = {

	{"mp2856", mp2856},

	{"mp2857", mp2857},

	{}

};

MODULE_DEVICE_TABLE(i2c, mp2856_id);

struct mp2856_data {

	struct pmbus_driver_info info;

	int vout_format[MP2856_PAGE_NUM];

	int curr_sense_gain[MP2856_PAGE_NUM];

	int max_phases[MP2856_PAGE_NUM];

	enum chips chip_id;

};

#define to_mp2856_data(x)	container_of(x, struct mp2856_data, info)

#define MAX_LIN_MANTISSA	(1023 * 1000)

#define MIN_LIN_MANTISSA	(511 * 1000)

static u16 val2linear11(s64 val)

{

	s16 exponent = 0, mantissa;

	bool negative = false;

	if (val == 0)

		return 0;

	if (val < 0) {

		negative = true;

		val = -val;

	}

	/* Reduce large mantissa until it fits into 10 bit */

	while (val >= MAX_LIN_MANTISSA && exponent < 15) {

		exponent++;

		val >>= 1;

	}

	/* Increase small mantissa to improve precision */

	while (val < MIN_LIN_MANTISSA && exponent > -15) {

		exponent--;

		val <<= 1;

	}

	/* Convert mantissa from milli-units to units */

	mantissa = clamp_val(DIV_ROUND_CLOSEST_ULL(val, 1000), 0, 0x3ff);

	/* restore sign */

	if (negative)

		mantissa = -mantissa;

	/* Convert to 5 bit exponent, 11 bit mantissa */

	return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);

}

static int

mp2856_read_word_helper(struct i2c_client *client, int page, int phase, u8 reg,

			u16 mask)

{

	int ret = pmbus_read_word_data(client, page, phase, reg);

	return (ret > 0) ? ret & mask : ret;

}

static int

mp2856_read_vout(struct i2c_client *client, struct mp2856_data *data, int page,

		 int phase, u8 reg)

{

	int ret;

	ret = mp2856_read_word_helper(client, page, phase, reg,

				      GENMASK(9, 0));

	if (ret < 0)

		return ret;

	/* convert vout result to direct format */

	ret = (data->vout_format[page] == vid) ?

		((ret + 49) * 5) : ((ret * 1000) >> 8);

	return ret;

}

static int

mp2856_read_phase(struct i2c_client *client, struct mp2856_data *data,

		  int page, int phase, u8 reg)

{

	int ret;

	int val;

	ret = pmbus_read_word_data(client, page, phase, reg);

	if (ret < 0)

		return ret;

	if (!((phase + 1) % MP2856_PAGE_NUM))

		ret >>= 8;

	ret &= 0xff;

	/*

	 * Output value is calculated as: (READ_CSx * 12.5mV - 1.23V) / (Kcs * Rcs)

	 */

	val = (ret * 125) - 12300;

	return val2linear11(val);

}

static int

mp2856_read_phases(struct i2c_client *client, struct mp2856_data *data,

		   int page, int phase)

{

	int ret;

	if (page == 0) {

		switch (phase) {

		case 0 ... 1:

			ret = mp2856_read_phase(client, data, page, phase,

						MP2856_MFR_READ_CS1_2_R1);

			break;

		case 2 ... 3:

			ret = mp2856_read_phase(client, data, page, phase,

						MP2856_MFR_READ_CS3_4_R1);

			break;

		case 4 ... 5:

			ret = mp2856_read_phase(client, data, page, phase,

						MP2856_MFR_READ_CS5_6_R1);

			break;

		case 6 ... 7:

			ret = mp2856_read_phase(client, data, page, phase,

						MP2856_MFR_READ_CS7_8_R1);

			break;

		default:

			return -ENODATA;

		}

	} else {

		switch (phase) {

		case 0 ... 1:

			ret = mp2856_read_phase(client, data, page, phase,

						MP2856_MFR_READ_CS1_2_R2);

			break;

		case 2 ... 3:

			ret = mp2856_read_phase(client, data, page, phase,

						MP2856_MFR_READ_CS1_2_R2);

			break;

		default:

			return -ENODATA;

		}

	}

	return ret;

}

static int

mp2856_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 mp2856_data *data = to_mp2856_data(info);

	int ret;

	switch (reg) {

	case PMBUS_READ_VOUT:

		ret = mp2856_read_vout(client, data, page, phase, reg);

		break;

	case PMBUS_READ_IOUT:

		if (phase != 0xff)

			ret = mp2856_read_phases(client, data, page, phase);

		else

			ret = pmbus_read_word_data(client, page, phase, reg);

		break;

	default:

		return -ENODATA;

	}

	return ret;

}

static int

mp2856_read_byte_data(struct i2c_client *client, int page, int reg)

{

	switch (reg) {

	case PMBUS_VOUT_MODE:

		/* Enforce VOUT direct format. */

		return PB_VOUT_MODE_DIRECT;

	default:

		return -ENODATA;

	}

}

static int

mp2856_identify_multiphase(struct i2c_client *client, u8 reg, u8 max_phase,

			   u16 mask)

{

	int ret;

	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);

	if (ret < 0)

		return ret;

	ret = i2c_smbus_read_word_data(client, reg);

	if (ret < 0)

		return ret;

	ret &= mask;

	return (ret >= max_phase) ? max_phase : ret;

}

static int

mp2856_identify_multiphase_rail1(struct i2c_client *client,

				 struct mp2856_data *data)

{

	int ret, i;

	ret = mp2856_identify_multiphase(client, MP2856_MFR_VR_MULTI_CONFIG_R1,

					 MP2856_MAX_PHASE_RAIL1, GENMASK(3, 0));

	if (ret < 0)

		return ret;

	data->info.phases[0] = (ret > data->max_phases[0]) ?

				data->max_phases[0] : ret;

	for (i = 0 ; i < data->info.phases[0]; i++)

		data->info.pfunc[i] |= PMBUS_HAVE_IOUT;

	return 0;

}

static int

mp2856_identify_multiphase_rail2(struct i2c_client *client,

				 struct mp2856_data *data)

{

	int ret, i;

	ret = mp2856_identify_multiphase(client, MP2856_MFR_VR_MULTI_CONFIG_R2,

					 MP2856_MAX_PHASE_RAIL2, GENMASK(2, 0));

	if (ret < 0)

		return ret;

	data->info.phases[1] = (ret > data->max_phases[1]) ?

				data->max_phases[1] : ret;

	for (i = 0 ; i < data->info.phases[0]; i++)

		data->info.pfunc[i] |= PMBUS_HAVE_IOUT;

	return 0;

}

static int

mp2856_current_sense_gain_get(struct i2c_client *client,

			      struct mp2856_data *data)

{

	int i, ret;

	/*

	 * Obtain DrMOS current sense gain of power stage from the register

	 * MP2856_MFR_VR_CONFIG1, bits 13-12. The value is selected as below:

	 * 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A. Other

	 * values are invalid.

	 */

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

		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);

		if (ret < 0)

			return ret;

		ret = i2c_smbus_read_word_data(client,

					       MP2856_MFR_VR_CONFIG1);

		if (ret < 0)

			return ret;

		switch ((ret & MP2856_DRMOS_KCS) >> 12) {

		case 0:

			data->curr_sense_gain[i] = 50;

			break;

		case 1:

			data->curr_sense_gain[i] = 85;

			break;

		case 2:

			data->curr_sense_gain[i] = 97;

			break;

		default:

			data->curr_sense_gain[i] = 100;

			break;

		}

	}

	return 0;

}

static int

mp2856_identify_vout_format(struct i2c_client *client,

			    struct mp2856_data *data)

{

	int i, ret;

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

		ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, i);

		if (ret < 0)

			return ret;

		ret = i2c_smbus_read_word_data(client, MP2856_MFR_VR_CONFIG2);

		if (ret < 0)

			return ret;

		data->vout_format[i] = (ret & MP2856_VOUT_MODE) ? linear : vid;

	}

	return 0;

}

static bool

mp2856_is_rail2_active(struct i2c_client *client)

{

	int ret;

	ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 2);

	if (ret < 0)

		return true;

	ret = i2c_smbus_read_word_data(client, MP2856_MUL1_BOOT_SR_R2);

	if (ret < 0)

		return true;

	return (ret & MP2856_VR_ACTIVE) ? true : false;

}

static struct pmbus_driver_info mp2856_info = {

	.pages = MP2856_PAGE_NUM,

	.format[PSC_VOLTAGE_IN] = linear,

	.format[PSC_VOLTAGE_OUT] = direct,

	.format[PSC_TEMPERATURE] = linear,

	.format[PSC_CURRENT_IN] = linear,

	.format[PSC_CURRENT_OUT] = linear,

	.format[PSC_POWER] = linear,

	.m[PSC_VOLTAGE_OUT] = 1,

	.R[PSC_VOLTAGE_OUT] = 3,

	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |

		PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |

		PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT |

		PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT,

	.func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_IOUT |

		PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP,

	.read_byte_data = mp2856_read_byte_data,

	.read_word_data = mp2856_read_word_data,

};

static int mp2856_probe(struct i2c_client *client)

{

	struct pmbus_driver_info *info;

	struct mp2856_data *data;

	int ret;

	data = devm_kzalloc(&client->dev, sizeof(struct mp2856_data),

			    GFP_KERNEL);

	if (!data)

		return -ENOMEM;

	data->chip_id = (enum chips)(uintptr_t)i2c_get_match_data(client);

	memcpy(data->max_phases, mp2856_max_phases[data->chip_id],

	       sizeof(data->max_phases));

	memcpy(&data->info, &mp2856_info, sizeof(*info));

	info = &data->info;

	/* Identify multiphase configuration. */

	ret = mp2856_identify_multiphase_rail1(client, data);

	if (ret < 0)

		return ret;

	if (mp2856_is_rail2_active(client)) {

		ret = mp2856_identify_multiphase_rail2(client, data);

		if (ret < 0)

			return ret;

	} else {

		/* rail2 is not active */

		info->pages = 1;

	}

	/* Obtain current sense gain of power stage. */

	ret = mp2856_current_sense_gain_get(client, data);

	if (ret)

		return ret;

	/* Identify vout format. */

	ret = mp2856_identify_vout_format(client, data);

	if (ret)

		return ret;

	/* set the device to page 0 */

	i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);

	return pmbus_do_probe(client, info);

}

static const struct of_device_id __maybe_unused mp2856_of_match[] = {

	{.compatible = "mps,mp2856", .data = (void *)mp2856},

	{.compatible = "mps,mp2857", .data = (void *)mp2857},

	{}

};

MODULE_DEVICE_TABLE(of, mp2856_of_match);

static struct i2c_driver mp2856_driver = {

	.driver = {

		.name = "mp2856",

		.of_match_table = mp2856_of_match,

	},

	.probe = mp2856_probe,

	.id_table = mp2856_id,

};

module_i2c_driver(mp2856_driver);

MODULE_AUTHOR("Peter Yin <peter.yin@quantatw.com>");

MODULE_DESCRIPTION("PMBus driver for MPS MP2856/MP2857 device");

MODULE_LICENSE("GPL");

MODULE_IMPORT_NS(PMBUS);