blob: 72a7c261ef068db4166591bbad3cbbb3f9c98d0d [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Hardware monitoring driver for FSP 3Y-Power PSUs
*
* Copyright (c) 2021 Václav Kubernát, CESNET
*
* This driver is mostly reverse engineered with the help of a tool called pmbus_peek written by
* David Brownell (and later adopted by Jan Kundrát). The device has some sort of a timing issue
* when switching pages, details are explained in the code. The driver support is limited. It
* exposes only the values, that have been tested to work correctly. Unsupported values either
* aren't supported by the devices or their encondings are unknown.
*/
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include "pmbus.h"
#define YM2151_PAGE_12V_LOG 0x00
#define YM2151_PAGE_12V_REAL 0x00
#define YM2151_PAGE_5VSB_LOG 0x01
#define YM2151_PAGE_5VSB_REAL 0x20
#define YH5151E_PAGE_12V_LOG 0x00
#define YH5151E_PAGE_12V_REAL 0x00
#define YH5151E_PAGE_5V_LOG 0x01
#define YH5151E_PAGE_5V_REAL 0x10
#define YH5151E_PAGE_3V3_LOG 0x02
#define YH5151E_PAGE_3V3_REAL 0x11
enum chips {
ym2151e,
yh5151e
};
struct fsp3y_data {
struct pmbus_driver_info info;
int chip;
int page;
bool vout_linear_11;
};
#define to_fsp3y_data(x) container_of(x, struct fsp3y_data, info)
static int page_log_to_page_real(int page_log, enum chips chip)
{
switch (chip) {
case ym2151e:
switch (page_log) {
case YM2151_PAGE_12V_LOG:
return YM2151_PAGE_12V_REAL;
case YM2151_PAGE_5VSB_LOG:
return YM2151_PAGE_5VSB_REAL;
}
return -EINVAL;
case yh5151e:
switch (page_log) {
case YH5151E_PAGE_12V_LOG:
return YH5151E_PAGE_12V_REAL;
case YH5151E_PAGE_5V_LOG:
return YH5151E_PAGE_5V_REAL;
case YH5151E_PAGE_3V3_LOG:
return YH5151E_PAGE_3V3_REAL;
}
return -EINVAL;
}
return -EINVAL;
}
static int set_page(struct i2c_client *client, int page_log)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct fsp3y_data *data = to_fsp3y_data(info);
int rv;
int page_real;
if (page_log < 0)
return 0;
page_real = page_log_to_page_real(page_log, data->chip);
if (page_real < 0)
return page_real;
if (data->page != page_real) {
rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page_real);
if (rv < 0)
return rv;
data->page = page_real;
/*
* Testing showed that the device has a timing issue. After
* setting a page, it takes a while, before the device actually
* gives the correct values from the correct page. 20 ms was
* tested to be enough to not give wrong values (15 ms wasn't
* enough).
*/
usleep_range(20000, 30000);
}
return 0;
}
static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct fsp3y_data *data = to_fsp3y_data(info);
int rv;
/*
* Inject an exponent for non-compliant YH5151-E.
*/
if (data->vout_linear_11 && reg == PMBUS_VOUT_MODE)
return 0x1A;
rv = set_page(client, page);
if (rv < 0)
return rv;
return i2c_smbus_read_byte_data(client, reg);
}
static int fsp3y_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 fsp3y_data *data = to_fsp3y_data(info);
int rv;
/*
* This masks commands which weren't tested to work correctly. Some of
* the masked commands return 0xFFFF. These would probably get tagged as
* invalid by pmbus_core. Other ones do return values which might be
* useful (that is, they are not 0xFFFF), but their encoding is unknown,
* and so they are unsupported.
*/
switch (reg) {
case PMBUS_READ_FAN_SPEED_1:
case PMBUS_READ_IIN:
case PMBUS_READ_IOUT:
case PMBUS_READ_PIN:
case PMBUS_READ_POUT:
case PMBUS_READ_TEMPERATURE_1:
case PMBUS_READ_TEMPERATURE_2:
case PMBUS_READ_TEMPERATURE_3:
case PMBUS_READ_VIN:
case PMBUS_READ_VOUT:
case PMBUS_STATUS_WORD:
break;
default:
return -ENXIO;
}
rv = set_page(client, page);
if (rv < 0)
return rv;
rv = i2c_smbus_read_word_data(client, reg);
if (rv < 0)
return rv;
/*
* Handle YH-5151E non-compliant linear11 vout voltage.
*/
if (data->vout_linear_11 && reg == PMBUS_READ_VOUT)
rv = sign_extend32(rv, 10) & 0xffff;
return rv;
}
static struct pmbus_driver_info fsp3y_info[] = {
[ym2151e] = {
.pages = 2,
.func[YM2151_PAGE_12V_LOG] =
PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
PMBUS_HAVE_VIN | PMBUS_HAVE_IIN |
PMBUS_HAVE_FAN12,
.func[YM2151_PAGE_5VSB_LOG] =
PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT,
.read_word_data = fsp3y_read_word_data,
.read_byte_data = fsp3y_read_byte_data,
},
[yh5151e] = {
.pages = 3,
.func[YH5151E_PAGE_12V_LOG] =
PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
PMBUS_HAVE_POUT |
PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3,
.func[YH5151E_PAGE_5V_LOG] =
PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
PMBUS_HAVE_POUT,
.func[YH5151E_PAGE_3V3_LOG] =
PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
PMBUS_HAVE_POUT,
.read_word_data = fsp3y_read_word_data,
.read_byte_data = fsp3y_read_byte_data,
}
};
static int fsp3y_detect(struct i2c_client *client)
{
int rv;
u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
rv = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
if (rv < 0)
return rv;
buf[rv] = '\0';
if (rv == 8) {
if (!strcmp(buf, "YM-2151E"))
return ym2151e;
else if (!strcmp(buf, "YH-5151E"))
return yh5151e;
}
dev_err(&client->dev, "Unsupported model %.*s\n", rv, buf);
return -ENODEV;
}
static const struct i2c_device_id fsp3y_id[] = {
{"ym2151e", ym2151e},
{"yh5151e", yh5151e},
{ }
};
static int fsp3y_probe(struct i2c_client *client)
{
struct fsp3y_data *data;
const struct i2c_device_id *id;
int rv;
data = devm_kzalloc(&client->dev, sizeof(struct fsp3y_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->chip = fsp3y_detect(client);
if (data->chip < 0)
return data->chip;
id = i2c_match_id(fsp3y_id, client);
if (data->chip != id->driver_data)
dev_warn(&client->dev, "Device mismatch: Configured %s (%d), detected %d\n",
id->name, (int)id->driver_data, data->chip);
rv = i2c_smbus_read_byte_data(client, PMBUS_PAGE);
if (rv < 0)
return rv;
data->page = rv;
data->info = fsp3y_info[data->chip];
/*
* YH-5151E sometimes reports vout in linear11 and sometimes in
* linear16. This depends on the exact individual piece of hardware. One
* YH-5151E can use linear16 and another might use linear11 instead.
*
* The format can be recognized by reading VOUT_MODE - if it doesn't
* report a valid exponent, then vout uses linear11. Otherwise, the
* device is compliant and uses linear16.
*/
data->vout_linear_11 = false;
if (data->chip == yh5151e) {
rv = i2c_smbus_read_byte_data(client, PMBUS_VOUT_MODE);
if (rv < 0)
return rv;
if (rv == 0xFF)
data->vout_linear_11 = true;
}
return pmbus_do_probe(client, &data->info);
}
MODULE_DEVICE_TABLE(i2c, fsp3y_id);
static struct i2c_driver fsp3y_driver = {
.driver = {
.name = "fsp3y",
},
.probe = fsp3y_probe,
.id_table = fsp3y_id
};
module_i2c_driver(fsp3y_driver);
MODULE_AUTHOR("Václav Kubernát");
MODULE_DESCRIPTION("PMBus driver for FSP/3Y-Power power supplies");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(PMBUS);