blob: 6969350f5d7d498ef74caceca5fa8e553b1f338a [file] [log] [blame]
// 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);