mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 02:39:48 +00:00
![Guenter Roeck](/assets/img/avatar_default.png)
Exported pmbus symbols are only supposed to be used from PMBus code. Introduce PMBUS symbol namespace to prevent misuse from other code. Signed-off-by: Guenter Roeck <linux@roeck-us.net>
190 lines
4.7 KiB
C
190 lines
4.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Hardware monitoring driver for Maxim MAX15301
|
|
*
|
|
* Copyright (c) 2021 Flextronics International Sweden AB
|
|
*
|
|
* Even though the specification does not specifically mention it,
|
|
* extensive empirical testing has revealed that auto-detection of
|
|
* limit-registers will fail in a random fashion unless the delay
|
|
* parameter is set to above about 80us. The default delay is set
|
|
* to 100us to include some safety margin.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/err.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/ktime.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/pmbus.h>
|
|
#include "pmbus.h"
|
|
|
|
static const struct i2c_device_id max15301_id[] = {
|
|
{"bmr461", 0},
|
|
{"max15301", 0},
|
|
{}
|
|
};
|
|
MODULE_DEVICE_TABLE(i2c, max15301_id);
|
|
|
|
struct max15301_data {
|
|
int id;
|
|
ktime_t access; /* Chip access time */
|
|
int delay; /* Delay between chip accesses in us */
|
|
struct pmbus_driver_info info;
|
|
};
|
|
|
|
#define to_max15301_data(x) container_of(x, struct max15301_data, info)
|
|
|
|
#define MAX15301_WAIT_TIME 100 /* us */
|
|
|
|
static ushort delay = MAX15301_WAIT_TIME;
|
|
module_param(delay, ushort, 0644);
|
|
MODULE_PARM_DESC(delay, "Delay between chip accesses in us");
|
|
|
|
static struct max15301_data max15301_data = {
|
|
.info = {
|
|
.pages = 1,
|
|
.func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
|
|
| PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
|
|
| PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
|
|
| PMBUS_HAVE_STATUS_TEMP
|
|
| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT,
|
|
}
|
|
};
|
|
|
|
/* This chip needs a delay between accesses */
|
|
static inline void max15301_wait(const struct max15301_data *data)
|
|
{
|
|
if (data->delay) {
|
|
s64 delta = ktime_us_delta(ktime_get(), data->access);
|
|
|
|
if (delta < data->delay)
|
|
udelay(data->delay - delta);
|
|
}
|
|
}
|
|
|
|
static int max15301_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 max15301_data *data = to_max15301_data(info);
|
|
int ret;
|
|
|
|
if (page > 0)
|
|
return -ENXIO;
|
|
|
|
if (reg >= PMBUS_VIRT_BASE)
|
|
return -ENXIO;
|
|
|
|
max15301_wait(data);
|
|
ret = pmbus_read_word_data(client, page, phase, reg);
|
|
data->access = ktime_get();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int max15301_read_byte_data(struct i2c_client *client, int page, int reg)
|
|
{
|
|
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
|
|
struct max15301_data *data = to_max15301_data(info);
|
|
int ret;
|
|
|
|
if (page > 0)
|
|
return -ENXIO;
|
|
|
|
max15301_wait(data);
|
|
ret = pmbus_read_byte_data(client, page, reg);
|
|
data->access = ktime_get();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int max15301_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 max15301_data *data = to_max15301_data(info);
|
|
int ret;
|
|
|
|
if (page > 0)
|
|
return -ENXIO;
|
|
|
|
if (reg >= PMBUS_VIRT_BASE)
|
|
return -ENXIO;
|
|
|
|
max15301_wait(data);
|
|
ret = pmbus_write_word_data(client, page, reg, word);
|
|
data->access = ktime_get();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int max15301_write_byte(struct i2c_client *client, int page, u8 value)
|
|
{
|
|
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
|
|
struct max15301_data *data = to_max15301_data(info);
|
|
int ret;
|
|
|
|
if (page > 0)
|
|
return -ENXIO;
|
|
|
|
max15301_wait(data);
|
|
ret = pmbus_write_byte(client, page, value);
|
|
data->access = ktime_get();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int max15301_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 = &max15301_data.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_IC_DEVICE_ID, device_id);
|
|
if (status < 0) {
|
|
dev_err(&client->dev, "Failed to read Device Id\n");
|
|
return status;
|
|
}
|
|
for (mid = max15301_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;
|
|
}
|
|
|
|
max15301_data.delay = delay;
|
|
|
|
info->read_byte_data = max15301_read_byte_data;
|
|
info->read_word_data = max15301_read_word_data;
|
|
info->write_byte = max15301_write_byte;
|
|
info->write_word_data = max15301_write_word_data;
|
|
|
|
return pmbus_do_probe(client, info);
|
|
}
|
|
|
|
static struct i2c_driver max15301_driver = {
|
|
.driver = {
|
|
.name = "max15301",
|
|
},
|
|
.probe_new = max15301_probe,
|
|
.id_table = max15301_id,
|
|
};
|
|
|
|
module_i2c_driver(max15301_driver);
|
|
|
|
MODULE_AUTHOR("Erik Rosen <erik.rosen@metormote.com>");
|
|
MODULE_DESCRIPTION("PMBus driver for Maxim MAX15301");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_IMPORT_NS(PMBUS);
|