linux_dsm_epyc7002/drivers/mfd/88pm860x-i2c.c
Peter Rosin 8c8f74f327 mfd: 88pm860x-i2c: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
Locking the root adapter for __i2c_transfer will deadlock if the
device sits behind a mux-locked I2C mux. Switch to the finer-grained
i2c_lock_bus with the I2C_LOCK_SEGMENT flag. If the device does not
sit behind a mux-locked mux, the two locking variants are equivalent.

Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-07-13 00:09:36 +02:00

178 lines
4.3 KiB
C

/*
* I2C driver for Marvell 88PM860x
*
* Copyright (C) 2009 Marvell International Ltd.
*
* Author: Haojian Zhuang <haojian.zhuang@marvell.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/mfd/88pm860x.h>
int pm860x_reg_read(struct i2c_client *i2c, int reg)
{
struct pm860x_chip *chip = i2c_get_clientdata(i2c);
struct regmap *map = (i2c == chip->client) ? chip->regmap
: chip->regmap_companion;
unsigned int data;
int ret;
ret = regmap_read(map, reg, &data);
if (ret < 0)
return ret;
else
return (int)data;
}
EXPORT_SYMBOL(pm860x_reg_read);
int pm860x_reg_write(struct i2c_client *i2c, int reg,
unsigned char data)
{
struct pm860x_chip *chip = i2c_get_clientdata(i2c);
struct regmap *map = (i2c == chip->client) ? chip->regmap
: chip->regmap_companion;
int ret;
ret = regmap_write(map, reg, data);
return ret;
}
EXPORT_SYMBOL(pm860x_reg_write);
int pm860x_bulk_read(struct i2c_client *i2c, int reg,
int count, unsigned char *buf)
{
struct pm860x_chip *chip = i2c_get_clientdata(i2c);
struct regmap *map = (i2c == chip->client) ? chip->regmap
: chip->regmap_companion;
int ret;
ret = regmap_raw_read(map, reg, buf, count);
return ret;
}
EXPORT_SYMBOL(pm860x_bulk_read);
int pm860x_bulk_write(struct i2c_client *i2c, int reg,
int count, unsigned char *buf)
{
struct pm860x_chip *chip = i2c_get_clientdata(i2c);
struct regmap *map = (i2c == chip->client) ? chip->regmap
: chip->regmap_companion;
int ret;
ret = regmap_raw_write(map, reg, buf, count);
return ret;
}
EXPORT_SYMBOL(pm860x_bulk_write);
int pm860x_set_bits(struct i2c_client *i2c, int reg,
unsigned char mask, unsigned char data)
{
struct pm860x_chip *chip = i2c_get_clientdata(i2c);
struct regmap *map = (i2c == chip->client) ? chip->regmap
: chip->regmap_companion;
int ret;
ret = regmap_update_bits(map, reg, mask, data);
return ret;
}
EXPORT_SYMBOL(pm860x_set_bits);
static int read_device(struct i2c_client *i2c, int reg,
int bytes, void *dest)
{
unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX + 3];
unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX + 2];
struct i2c_adapter *adap = i2c->adapter;
struct i2c_msg msg[2] = {
{
.addr = i2c->addr,
.flags = 0,
.len = 1,
.buf = msgbuf0
},
{ .addr = i2c->addr,
.flags = I2C_M_RD,
.len = 0,
.buf = msgbuf1
},
};
int num = 1, ret = 0;
if (dest == NULL)
return -EINVAL;
msgbuf0[0] = (unsigned char)reg; /* command */
msg[1].len = bytes;
/* if data needs to read back, num should be 2 */
if (bytes > 0)
num = 2;
ret = adap->algo->master_xfer(adap, msg, num);
memcpy(dest, msgbuf1, bytes);
if (ret < 0)
return ret;
return 0;
}
static int write_device(struct i2c_client *i2c, int reg,
int bytes, void *src)
{
unsigned char buf[2];
struct i2c_adapter *adap = i2c->adapter;
struct i2c_msg msg;
int ret;
buf[0] = (unsigned char)reg;
memcpy(&buf[1], src, bytes);
msg.addr = i2c->addr;
msg.flags = 0;
msg.len = bytes + 1;
msg.buf = buf;
ret = adap->algo->master_xfer(adap, &msg, 1);
if (ret < 0)
return ret;
return 0;
}
int pm860x_page_reg_write(struct i2c_client *i2c, int reg,
unsigned char data)
{
unsigned char zero;
int ret;
i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
read_device(i2c, 0xFA, 0, &zero);
read_device(i2c, 0xFB, 0, &zero);
read_device(i2c, 0xFF, 0, &zero);
ret = write_device(i2c, reg, 1, &data);
read_device(i2c, 0xFE, 0, &zero);
read_device(i2c, 0xFC, 0, &zero);
i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
return ret;
}
EXPORT_SYMBOL(pm860x_page_reg_write);
int pm860x_page_bulk_read(struct i2c_client *i2c, int reg,
int count, unsigned char *buf)
{
unsigned char zero = 0;
int ret;
i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
read_device(i2c, 0xfa, 0, &zero);
read_device(i2c, 0xfb, 0, &zero);
read_device(i2c, 0xff, 0, &zero);
ret = read_device(i2c, reg, count, buf);
read_device(i2c, 0xFE, 0, &zero);
read_device(i2c, 0xFC, 0, &zero);
i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
return ret;
}
EXPORT_SYMBOL(pm860x_page_bulk_read);