409 lines
11 KiB
C
409 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
||
/*
|
||
* Hardware monitoring driver for MPS Multi-phase Digital VR Controllers
|
||
*
|
||
* Copyright (C) 2020 Nvidia Technologies Ltd.
|
||
*/
|
||
|
||
#include <linux/err.h>
|
||
#include <linux/i2c.h>
|
||
#include <linux/init.h>
|
||
#include <linux/kernel.h>
|
||
#include <linux/module.h>
|
||
#include "pmbus.h"
|
||
|
||
/* Vendor specific registers. */
|
||
#define MP2888_MFR_SYS_CONFIG 0x44
|
||
#define MP2888_MFR_READ_CS1_2 0x73
|
||
#define MP2888_MFR_READ_CS3_4 0x74
|
||
#define MP2888_MFR_READ_CS5_6 0x75
|
||
#define MP2888_MFR_READ_CS7_8 0x76
|
||
#define MP2888_MFR_READ_CS9_10 0x77
|
||
#define MP2888_MFR_VR_CONFIG1 0xe1
|
||
|
||
#define MP2888_TOTAL_CURRENT_RESOLUTION BIT(3)
|
||
#define MP2888_PHASE_CURRENT_RESOLUTION BIT(4)
|
||
#define MP2888_DRMOS_KCS GENMASK(2, 0)
|
||
#define MP2888_TEMP_UNIT 10
|
||
#define MP2888_MAX_PHASE 10
|
||
|
||
struct mp2888_data {
|
||
struct pmbus_driver_info info;
|
||
int total_curr_resolution;
|
||
int phase_curr_resolution;
|
||
int curr_sense_gain;
|
||
};
|
||
|
||
#define to_mp2888_data(x) container_of(x, struct mp2888_data, info)
|
||
|
||
static int mp2888_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
|
||
mp2888_current_sense_gain_and_resolution_get(struct i2c_client *client, struct mp2888_data *data)
|
||
{
|
||
int ret;
|
||
|
||
/*
|
||
* Obtain DrMOS current sense gain of power stage from the register
|
||
* , bits 0-2. The value is selected as below:
|
||
* 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A. Other
|
||
* values are reserved.
|
||
*/
|
||
ret = i2c_smbus_read_word_data(client, MP2888_MFR_SYS_CONFIG);
|
||
if (ret < 0)
|
||
return ret;
|
||
|
||
switch (ret & MP2888_DRMOS_KCS) {
|
||
case 0:
|
||
data->curr_sense_gain = 85;
|
||
break;
|
||
case 1:
|
||
data->curr_sense_gain = 97;
|
||
break;
|
||
case 2:
|
||
data->curr_sense_gain = 100;
|
||
break;
|
||
case 3:
|
||
data->curr_sense_gain = 50;
|
||
break;
|
||
default:
|
||
return -EINVAL;
|
||
}
|
||
|
||
/*
|
||
* Obtain resolution selector for total and phase current report and protection.
|
||
* 0: original resolution; 1: half resolution (in such case phase current value should
|
||
* be doubled.
|
||
*/
|
||
data->total_curr_resolution = (ret & MP2888_TOTAL_CURRENT_RESOLUTION) >> 3;
|
||
data->phase_curr_resolution = (ret & MP2888_PHASE_CURRENT_RESOLUTION) >> 4;
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int
|
||
mp2888_read_phase(struct i2c_client *client, struct mp2888_data *data, int page, int phase, u8 reg)
|
||
{
|
||
int ret;
|
||
|
||
ret = pmbus_read_word_data(client, page, phase, reg);
|
||
if (ret < 0)
|
||
return ret;
|
||
|
||
if (!((phase + 1) % 2))
|
||
ret >>= 8;
|
||
ret &= 0xff;
|
||
|
||
/*
|
||
* Output value is calculated as: (READ_CSx / 80 – 1.23) / (Kcs * Rcs)
|
||
* where:
|
||
* - Kcs is the DrMOS current sense gain of power stage, which is obtained from the
|
||
* register MP2888_MFR_VR_CONFIG1, bits 13-12 with the following selection of DrMOS
|
||
* (data->curr_sense_gain):
|
||
* 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A.
|
||
* - Rcs is the internal phase current sense resistor. This parameter depends on hardware
|
||
* assembly. By default it is set to 1kΩ. In case of different assembly, user should
|
||
* scale this parameter by dividing it by Rcs.
|
||
* If phase current resolution bit is set to 1, READ_CSx value should be doubled.
|
||
* Note, that current phase sensing, providing by the device is not accurate. This is
|
||
* because sampling of current occurrence of bit weight has a big deviation, especially for
|
||
* light load.
|
||
*/
|
||
ret = DIV_ROUND_CLOSEST(ret * 100 - 9800, data->curr_sense_gain);
|
||
ret = (data->phase_curr_resolution) ? ret * 2 : ret;
|
||
/* Scale according to total current resolution. */
|
||
ret = (data->total_curr_resolution) ? ret * 8 : ret * 4;
|
||
return ret;
|
||
}
|
||
|
||
static int
|
||
mp2888_read_phases(struct i2c_client *client, struct mp2888_data *data, int page, int phase)
|
||
{
|
||
int ret;
|
||
|
||
switch (phase) {
|
||
case 0 ... 1:
|
||
ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS1_2);
|
||
break;
|
||
case 2 ... 3:
|
||
ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS3_4);
|
||
break;
|
||
case 4 ... 5:
|
||
ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS5_6);
|
||
break;
|
||
case 6 ... 7:
|
||
ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS7_8);
|
||
break;
|
||
case 8 ... 9:
|
||
ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS9_10);
|
||
break;
|
||
default:
|
||
return -ENODATA;
|
||
}
|
||
return ret;
|
||
}
|
||
|
||
static int mp2888_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 mp2888_data *data = to_mp2888_data(info);
|
||
int ret;
|
||
|
||
switch (reg) {
|
||
case PMBUS_READ_VIN:
|
||
ret = pmbus_read_word_data(client, page, phase, reg);
|
||
if (ret <= 0)
|
||
return ret;
|
||
|
||
/*
|
||
* READ_VIN requires fixup to scale it to linear11 format. Register data format
|
||
* provides 10 bits for mantissa and 6 bits for exponent. Bits 15:10 are set with
|
||
* the fixed value 111011b.
|
||
*/
|
||
ret = (ret & GENMASK(9, 0)) | ((ret & GENMASK(31, 10)) << 1);
|
||
break;
|
||
case PMBUS_OT_WARN_LIMIT:
|
||
ret = pmbus_read_word_data(client, page, phase, reg);
|
||
if (ret < 0)
|
||
return ret;
|
||
/*
|
||
* Chip reports limits in degrees C, but the actual temperature in 10th of
|
||
* degrees C - scaling is needed to match both.
|
||
*/
|
||
ret *= MP2888_TEMP_UNIT;
|
||
break;
|
||
case PMBUS_READ_IOUT:
|
||
if (phase != 0xff)
|
||
return mp2888_read_phases(client, data, page, phase);
|
||
|
||
ret = pmbus_read_word_data(client, page, phase, reg);
|
||
if (ret < 0)
|
||
return ret;
|
||
/*
|
||
* READ_IOUT register has unused bits 15:12 with fixed value 1110b. Clear these
|
||
* bits and scale with total current resolution. Data is provided in direct format.
|
||
*/
|
||
ret &= GENMASK(11, 0);
|
||
ret = data->total_curr_resolution ? ret * 2 : ret;
|
||
break;
|
||
case PMBUS_IOUT_OC_WARN_LIMIT:
|
||
ret = pmbus_read_word_data(client, page, phase, reg);
|
||
if (ret < 0)
|
||
return ret;
|
||
ret &= GENMASK(9, 0);
|
||
/*
|
||
* Chip reports limits with resolution 1A or 2A, if total current resolution bit is
|
||
* set 1. Actual current is reported with 0.25A or respectively 0.5A resolution.
|
||
* Scaling is needed to match both.
|
||
*/
|
||
ret = data->total_curr_resolution ? ret * 8 : ret * 4;
|
||
break;
|
||
case PMBUS_READ_POUT:
|
||
case PMBUS_READ_PIN:
|
||
ret = pmbus_read_word_data(client, page, phase, reg);
|
||
if (ret < 0)
|
||
return ret;
|
||
ret = data->total_curr_resolution ? ret * 2 : ret;
|
||
break;
|
||
case PMBUS_POUT_OP_WARN_LIMIT:
|
||
ret = pmbus_read_word_data(client, page, phase, reg);
|
||
if (ret < 0)
|
||
return ret;
|
||
/*
|
||
* Chip reports limits with resolution 1W or 2W, if total current resolution bit is
|
||
* set 1. Actual power is reported with 0.5W or 1W respectively resolution. Scaling
|
||
* is needed to match both.
|
||
*/
|
||
ret = data->total_curr_resolution ? ret * 4 : ret * 2;
|
||
break;
|
||
/*
|
||
* The below registers are not implemented by device or implemented not according to the
|
||
* spec. Skip all of them to avoid exposing non-relevant inputs to sysfs.
|
||
*/
|
||
case PMBUS_OT_FAULT_LIMIT:
|
||
case PMBUS_UT_WARN_LIMIT:
|
||
case PMBUS_UT_FAULT_LIMIT:
|
||
case PMBUS_VIN_UV_FAULT_LIMIT:
|
||
case PMBUS_VOUT_UV_WARN_LIMIT:
|
||
case PMBUS_VOUT_OV_WARN_LIMIT:
|
||
case PMBUS_VOUT_UV_FAULT_LIMIT:
|
||
case PMBUS_VOUT_OV_FAULT_LIMIT:
|
||
case PMBUS_VIN_OV_WARN_LIMIT:
|
||
case PMBUS_IOUT_OC_LV_FAULT_LIMIT:
|
||
case PMBUS_IOUT_OC_FAULT_LIMIT:
|
||
case PMBUS_POUT_MAX:
|
||
case PMBUS_IOUT_UC_FAULT_LIMIT:
|
||
case PMBUS_POUT_OP_FAULT_LIMIT:
|
||
case PMBUS_PIN_OP_WARN_LIMIT:
|
||
case PMBUS_MFR_VIN_MIN:
|
||
case PMBUS_MFR_VOUT_MIN:
|
||
case PMBUS_MFR_VIN_MAX:
|
||
case PMBUS_MFR_VOUT_MAX:
|
||
case PMBUS_MFR_IIN_MAX:
|
||
case PMBUS_MFR_IOUT_MAX:
|
||
case PMBUS_MFR_PIN_MAX:
|
||
case PMBUS_MFR_POUT_MAX:
|
||
case PMBUS_MFR_MAX_TEMP_1:
|
||
return -ENXIO;
|
||
default:
|
||
return -ENODATA;
|
||
}
|
||
|
||
return ret;
|
||
}
|
||
|
||
static int mp2888_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 mp2888_data *data = to_mp2888_data(info);
|
||
|
||
switch (reg) {
|
||
case PMBUS_OT_WARN_LIMIT:
|
||
word = DIV_ROUND_CLOSEST(word, MP2888_TEMP_UNIT);
|
||
/* Drop unused bits 15:8. */
|
||
word = clamp_val(word, 0, GENMASK(7, 0));
|
||
break;
|
||
case PMBUS_IOUT_OC_WARN_LIMIT:
|
||
/* Fix limit according to total curent resolution. */
|
||
word = data->total_curr_resolution ? DIV_ROUND_CLOSEST(word, 8) :
|
||
DIV_ROUND_CLOSEST(word, 4);
|
||
/* Drop unused bits 15:10. */
|
||
word = clamp_val(word, 0, GENMASK(9, 0));
|
||
break;
|
||
case PMBUS_POUT_OP_WARN_LIMIT:
|
||
/* Fix limit according to total curent resolution. */
|
||
word = data->total_curr_resolution ? DIV_ROUND_CLOSEST(word, 4) :
|
||
DIV_ROUND_CLOSEST(word, 2);
|
||
/* Drop unused bits 15:10. */
|
||
word = clamp_val(word, 0, GENMASK(9, 0));
|
||
break;
|
||
default:
|
||
return -ENODATA;
|
||
}
|
||
return pmbus_write_word_data(client, page, reg, word);
|
||
}
|
||
|
||
static int
|
||
mp2888_identify_multiphase(struct i2c_client *client, struct mp2888_data *data,
|
||
struct pmbus_driver_info *info)
|
||
{
|
||
int ret;
|
||
|
||
ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
|
||
if (ret < 0)
|
||
return ret;
|
||
|
||
/* Identify multiphase number - could be from 1 to 10. */
|
||
ret = i2c_smbus_read_word_data(client, MP2888_MFR_VR_CONFIG1);
|
||
if (ret <= 0)
|
||
return ret;
|
||
|
||
info->phases[0] = ret & GENMASK(3, 0);
|
||
|
||
/*
|
||
* The device provides a total of 10 PWM pins, and can be configured to different phase
|
||
* count applications for rail.
|
||
*/
|
||
if (info->phases[0] > MP2888_MAX_PHASE)
|
||
return -EINVAL;
|
||
|
||
return 0;
|
||
}
|
||
|
||
static struct pmbus_driver_info mp2888_info = {
|
||
.pages = 1,
|
||
.format[PSC_VOLTAGE_IN] = linear,
|
||
.format[PSC_VOLTAGE_OUT] = direct,
|
||
.format[PSC_TEMPERATURE] = direct,
|
||
.format[PSC_CURRENT_IN] = linear,
|
||
.format[PSC_CURRENT_OUT] = direct,
|
||
.format[PSC_POWER] = direct,
|
||
.m[PSC_TEMPERATURE] = 1,
|
||
.R[PSC_TEMPERATURE] = 1,
|
||
.m[PSC_VOLTAGE_OUT] = 1,
|
||
.R[PSC_VOLTAGE_OUT] = 3,
|
||
.m[PSC_CURRENT_OUT] = 4,
|
||
.m[PSC_POWER] = 1,
|
||
.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_IOUT |
|
||
PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |
|
||
PMBUS_HAVE_POUT | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT |
|
||
PMBUS_PHASE_VIRTUAL,
|
||
.pfunc[0] = PMBUS_HAVE_IOUT,
|
||
.pfunc[1] = PMBUS_HAVE_IOUT,
|
||
.pfunc[2] = PMBUS_HAVE_IOUT,
|
||
.pfunc[3] = PMBUS_HAVE_IOUT,
|
||
.pfunc[4] = PMBUS_HAVE_IOUT,
|
||
.pfunc[5] = PMBUS_HAVE_IOUT,
|
||
.pfunc[6] = PMBUS_HAVE_IOUT,
|
||
.pfunc[7] = PMBUS_HAVE_IOUT,
|
||
.pfunc[8] = PMBUS_HAVE_IOUT,
|
||
.pfunc[9] = PMBUS_HAVE_IOUT,
|
||
.read_byte_data = mp2888_read_byte_data,
|
||
.read_word_data = mp2888_read_word_data,
|
||
.write_word_data = mp2888_write_word_data,
|
||
};
|
||
|
||
static int mp2888_probe(struct i2c_client *client)
|
||
{
|
||
struct pmbus_driver_info *info;
|
||
struct mp2888_data *data;
|
||
int ret;
|
||
|
||
data = devm_kzalloc(&client->dev, sizeof(struct mp2888_data), GFP_KERNEL);
|
||
if (!data)
|
||
return -ENOMEM;
|
||
|
||
memcpy(&data->info, &mp2888_info, sizeof(*info));
|
||
info = &data->info;
|
||
|
||
/* Identify multiphase configuration. */
|
||
ret = mp2888_identify_multiphase(client, data, info);
|
||
if (ret)
|
||
return ret;
|
||
|
||
/* Obtain current sense gain of power stage and current resolution. */
|
||
ret = mp2888_current_sense_gain_and_resolution_get(client, data);
|
||
if (ret)
|
||
return ret;
|
||
|
||
return pmbus_do_probe(client, info);
|
||
}
|
||
|
||
static const struct i2c_device_id mp2888_id[] = {
|
||
{"mp2888", 0},
|
||
{}
|
||
};
|
||
|
||
MODULE_DEVICE_TABLE(i2c, mp2888_id);
|
||
|
||
static const struct of_device_id __maybe_unused mp2888_of_match[] = {
|
||
{.compatible = "mps,mp2888"},
|
||
{}
|
||
};
|
||
MODULE_DEVICE_TABLE(of, mp2888_of_match);
|
||
|
||
static struct i2c_driver mp2888_driver = {
|
||
.driver = {
|
||
.name = "mp2888",
|
||
.of_match_table = of_match_ptr(mp2888_of_match),
|
||
},
|
||
.probe_new = mp2888_probe,
|
||
.id_table = mp2888_id,
|
||
};
|
||
|
||
module_i2c_driver(mp2888_driver);
|
||
|
||
MODULE_AUTHOR("Vadim Pasternak <vadimp@nvidia.com>");
|
||
MODULE_DESCRIPTION("PMBus driver for MPS MP2888 device");
|
||
MODULE_LICENSE("GPL");
|
||
MODULE_IMPORT_NS(PMBUS);
|