blob: be9076dcc2dbf224427c1f4909c7372ce817f31a [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Hardware monitoring driver for the STPDDC60 controller
*
* Copyright (c) 2021 Flextronics International Sweden AB.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/pmbus.h>
#include "pmbus.h"
#define STPDDC60_MFR_READ_VOUT 0xd2
#define STPDDC60_MFR_OV_LIMIT_OFFSET 0xe5
#define STPDDC60_MFR_UV_LIMIT_OFFSET 0xe6
static const struct i2c_device_id stpddc60_id[] = {
{"stpddc60", 0},
{"bmr481", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, stpddc60_id);
static struct pmbus_driver_info stpddc60_info = {
.pages = 1,
.func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
| PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
| PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
| PMBUS_HAVE_POUT,
};
/*
* Calculate the closest absolute offset between commanded vout value
* and limit value in steps of 50mv in the range 0 (50mv) to 7 (400mv).
* Return 0 if the upper limit is lower than vout or if the lower limit
* is higher than vout.
*/
static u8 stpddc60_get_offset(int vout, u16 limit, bool over)
{
int offset;
long v, l;
v = 250 + (vout - 1) * 5; /* Convert VID to mv */
l = (limit * 1000L) >> 8; /* Convert LINEAR to mv */
if (over == (l < v))
return 0;
offset = DIV_ROUND_CLOSEST(abs(l - v), 50);
if (offset > 0)
offset--;
return clamp_val(offset, 0, 7);
}
/*
* Adjust the linear format word to use the given fixed exponent.
*/
static u16 stpddc60_adjust_linear(u16 word, s16 fixed)
{
s16 e, m, d;
e = ((s16)word) >> 11;
m = ((s16)((word & 0x7ff) << 5)) >> 5;
d = e - fixed;
if (d >= 0)
m <<= d;
else
m >>= -d;
return clamp_val(m, 0, 0x3ff) | ((fixed << 11) & 0xf800);
}
/*
* The VOUT_COMMAND register uses the VID format but the vout alarm limit
* registers use the LINEAR format so we override VOUT_MODE here to force
* LINEAR format for all registers.
*/
static int stpddc60_read_byte_data(struct i2c_client *client, int page, int reg)
{
int ret;
if (page > 0)
return -ENXIO;
switch (reg) {
case PMBUS_VOUT_MODE:
ret = 0x18;
break;
default:
ret = -ENODATA;
break;
}
return ret;
}
/*
* The vout related registers return values in LINEAR11 format when LINEAR16
* is expected. Clear the top 5 bits to set the exponent part to zero to
* convert the value to LINEAR16 format.
*/
static int stpddc60_read_word_data(struct i2c_client *client, int page,
int phase, int reg)
{
int ret;
if (page > 0)
return -ENXIO;
switch (reg) {
case PMBUS_READ_VOUT:
ret = pmbus_read_word_data(client, page, phase,
STPDDC60_MFR_READ_VOUT);
if (ret < 0)
return ret;
ret &= 0x7ff;
break;
case PMBUS_VOUT_OV_FAULT_LIMIT:
case PMBUS_VOUT_UV_FAULT_LIMIT:
ret = pmbus_read_word_data(client, page, phase, reg);
if (ret < 0)
return ret;
ret &= 0x7ff;
break;
default:
ret = -ENODATA;
break;
}
return ret;
}
/*
* The vout under- and over-voltage limits are set as an offset relative to
* the commanded vout voltage. The vin, iout, pout and temp limits must use
* the same fixed exponent the chip uses to encode the data when read.
*/
static int stpddc60_write_word_data(struct i2c_client *client, int page,
int reg, u16 word)
{
int ret;
u8 offset;
if (page > 0)
return -ENXIO;
switch (reg) {
case PMBUS_VOUT_OV_FAULT_LIMIT:
ret = pmbus_read_word_data(client, page, 0xff,
PMBUS_VOUT_COMMAND);
if (ret < 0)
return ret;
offset = stpddc60_get_offset(ret, word, true);
ret = pmbus_write_byte_data(client, page,
STPDDC60_MFR_OV_LIMIT_OFFSET,
offset);
break;
case PMBUS_VOUT_UV_FAULT_LIMIT:
ret = pmbus_read_word_data(client, page, 0xff,
PMBUS_VOUT_COMMAND);
if (ret < 0)
return ret;
offset = stpddc60_get_offset(ret, word, false);
ret = pmbus_write_byte_data(client, page,
STPDDC60_MFR_UV_LIMIT_OFFSET,
offset);
break;
case PMBUS_VIN_OV_FAULT_LIMIT:
case PMBUS_VIN_UV_FAULT_LIMIT:
case PMBUS_OT_FAULT_LIMIT:
case PMBUS_OT_WARN_LIMIT:
case PMBUS_IOUT_OC_FAULT_LIMIT:
case PMBUS_IOUT_OC_WARN_LIMIT:
case PMBUS_POUT_OP_FAULT_LIMIT:
ret = pmbus_read_word_data(client, page, 0xff, reg);
if (ret < 0)
return ret;
word = stpddc60_adjust_linear(word, ret >> 11);
ret = pmbus_write_word_data(client, page, reg, word);
break;
default:
ret = -ENODATA;
break;
}
return ret;
}
static int stpddc60_probe(struct i2c_client *client)
{
int status;
u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
const struct i2c_device_id *mid;
struct pmbus_driver_info *info = &stpddc60_info;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_BYTE_DATA
| I2C_FUNC_SMBUS_BLOCK_DATA))
return -ENODEV;
status = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, device_id);
if (status < 0) {
dev_err(&client->dev, "Failed to read Manufacturer Model\n");
return status;
}
for (mid = stpddc60_id; mid->name[0]; mid++) {
if (!strncasecmp(mid->name, device_id, strlen(mid->name)))
break;
}
if (!mid->name[0]) {
dev_err(&client->dev, "Unsupported device\n");
return -ENODEV;
}
info->read_byte_data = stpddc60_read_byte_data;
info->read_word_data = stpddc60_read_word_data;
info->write_word_data = stpddc60_write_word_data;
status = pmbus_do_probe(client, info);
if (status < 0)
return status;
pmbus_set_update(client, PMBUS_VOUT_OV_FAULT_LIMIT, true);
pmbus_set_update(client, PMBUS_VOUT_UV_FAULT_LIMIT, true);
return 0;
}
static struct i2c_driver stpddc60_driver = {
.driver = {
.name = "stpddc60",
},
.probe = stpddc60_probe,
.id_table = stpddc60_id,
};
module_i2c_driver(stpddc60_driver);
MODULE_AUTHOR("Erik Rosen <erik.rosen@metormote.com>");
MODULE_DESCRIPTION("PMBus driver for ST STPDDC60");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(PMBUS);