/*
* Hardware monitoring driver for ZL6100 and compatibles
*
* Copyright (c) 2011 Ericsson AB.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#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 "pmbus.h"
enum chips { zl2004, zl2005, zl2006, zl2008, zl2105, zl2106, zl6100, zl6105 };
struct zl6100_data {
int id;
ktime_t access; /* chip access time */
struct pmbus_driver_info info;
};
#define to_zl6100_data(x) container_of(x, struct zl6100_data, info)
#define ZL6100_MFR_CONFIG 0xd0
#define ZL6100_DEVICE_ID 0xe4
#define ZL6100_MFR_XTEMP_ENABLE (1 << 7)
#define ZL6100_WAIT_TIME 1000 /* uS */
static ushort delay = ZL6100_WAIT_TIME;
module_param(delay, ushort, 0644);
MODULE_PARM_DESC(delay, "Delay between chip accesses in uS");
/* Some chips need a delay between accesses */
static inline void zl6100_wait(const struct zl6100_data *data)
{
if (delay) {
s64 delta = ktime_us_delta(ktime_get(), data->access);
if (delta < delay)
udelay(delay - delta);
}
}
static int zl6100_read_word_data(struct i2c_client *client, int page, int reg)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct zl6100_data *data = to_zl6100_data(info);
int ret;
if (page || reg >= PMBUS_VIRT_BASE)
return -ENXIO;
if (data->id == zl2005) {
/*
* Limit register detection is not reliable on ZL2005.
* Make sure registers are not erroneously detected.
*/
switch (reg) {
case PMBUS_VOUT_OV_WARN_LIMIT:
case PMBUS_VOUT_UV_WARN_LIMIT:
case PMBUS_IOUT_OC_WARN_LIMIT:
return -ENXIO;
}
}
zl6100_wait(data);
ret = pmbus_read_word_data(client, page, reg);
data->access = ktime_get();
return ret;
}
static int zl6100_read_byte_data(struct i2c_client *client, int page, int reg)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct zl6100_data *data = to_zl6100_data(info);
int ret;
if (page > 0)
return -ENXIO;
zl6100_wait(data);
ret = pmbus_read_byte_data(client, page, reg);
data->access = ktime_get();
return ret;
}
static int zl6100_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 zl6100_data *data = to_zl6100_data(info);
int ret;
if (page || reg >= PMBUS_VIRT_BASE)
return -ENXIO;
zl6100_wait(data);
ret = pmbus_write_word_data(client, page, reg, word);
data->access = ktime_get();
return ret;
}
static int zl6100_write_byte(struct i2c_client *client, int page, u8 value)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
struct zl6100_data *data = to_zl6100_data(info);
int ret;
if (page > 0)
return -ENXIO;
zl6100_wait(data);
ret = pmbus_write_byte(client, page, value);
data->access = ktime_get();
return ret;
}
static const struct i2c_device_id zl6100_id[] = {
{"bmr450", zl2005},
{"bmr451", zl2005},
{"bmr462", zl2008},
{"bmr463", zl2008},
{"bmr464", zl2008},
{"zl2004", zl2004},
{"zl2005", zl2005},
{"zl2006", zl2006},
{"zl2008", zl2008},
{"zl2105", zl2105},
{"zl2106", zl2106},
{"zl6100", zl6100},
{"zl6105", zl6105},
{ }
};
MODULE_DEVICE_TABLE(i2c, zl6100_id);
static int zl6100_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct zl6100_data *data;
struct pmbus_driver_info *info;
u8 device_id[I2C_SMBUS_BLOCK_MAX + 1];
const struct i2c_device_id *mid;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_WORD_DATA
| I2C_FUNC_SMBUS_READ_BLOCK_DATA))
return -ENODEV;
ret = i2c_smbus_read_block_data(client, ZL6100_DEVICE_ID,
device_id);
if (ret < 0) {
dev_err(&client->dev, "Failed to read device ID\n");
return ret;
}
device_id[ret] = '\0';
dev_info(&client->dev, "Device ID %s\n", device_id);
mid = NULL;
for (mid = zl6100_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;
}
if (id->driver_data != mid->driver_data)
dev_notice(&client->dev,
"Device mismatch: Configured %s, detected %s\n",
id->name, mid->name);
data = kzalloc(sizeof(struct zl6100_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->id = mid->driver_data;
/*
* ZL2005, ZL2008, ZL2105, and ZL6100 are known to require a wait time
* between I2C accesses. ZL2004 and ZL6105 are known to be safe.
* Other chips have not yet been tested.
*
* Only clear the wait time for chips known to be safe. The wait time
* can be cleared later for additional chips if tests show that it
* is not needed (in other words, better be safe than sorry).
*/
if (data->id == zl2004 || data->id == zl6105)
delay = 0;
/*
* Since there was a direct I2C device access above, wait before
* accessing the chip again.
*/
data->access = ktime_get();
zl6100_wait(data);
info = &data->info;
info->pages = 1;
info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
| PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
| PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
ret = i2c_smbus_read_word_data(client, ZL6100_MFR_CONFIG);
if (ret < 0)
goto err_mem;
if (ret & ZL6100_MFR_XTEMP_ENABLE)
info->func[0] |= PMBUS_HAVE_TEMP2;
data->access = ktime_get();
zl6100_wait(data);
info->read_word_data = zl6100_read_word_data;
info->read_byte_data = zl6100_read_byte_data;
info->write_word_data = zl6100_write_word_data;
info->write_byte = zl6100_write_byte;
ret = pmbus_do_probe(client, mid, info);
if (ret)
goto err_mem;
return 0;
err_mem:
kfree(data);
return ret;
}
static int zl6100_remove(struct i2c_client *client)
{
const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
const struct zl6100_data *data = to_zl6100_data(info);
pmbus_do_remove(client);
kfree(data);
return 0;
}
static struct i2c_driver zl6100_driver = {
.driver = {
.name = "zl6100",
},
.probe = zl6100_probe,
.remove = zl6100_remove,
.id_table = zl6100_id,
};
static int __init zl6100_init(void)
{
return i2c_add_driver(&zl6100_driver);
}
static void __exit zl6100_exit(void)
{
i2c_del_driver(&zl6100_driver);
}
MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for ZL6100 and compatibles");
MODULE_LICENSE("GPL");
module_init(zl6100_init);
module_exit(zl6100_exit);
