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/*
* Copyright (C) 2011 Alexander Aring <a.aring@phytec.de>
*
* Based on:
* Copyright (C) 2010 Michael Grzeschik <mgr@pengutronix.de>
*
* This file is released under the GPLv2
*
*/
#include <common.h>
#include <init.h>
#include <driver.h>
#include <xfuncs.h>
#include <errno.h>
#include <i2c/i2c.h>
#include <mfd/twl-core.h>
#define to_twlcore(a) container_of(a, struct twlcore, cdev)
static struct twlcore *twl_dev;
struct twlcore *twlcore_get(void)
{
return twl_dev;
}
EXPORT_SYMBOL(twlcore_get);
int twlcore_reg_read(struct twlcore *twlcore, u16 reg, u8 *val)
{
int ret;
struct i2c_msg xfer_msg[2];
struct i2c_msg *msg;
int i2c_addr;
unsigned char buf = reg & 0xff;
i2c_addr = twlcore->client->addr + (reg / 0x100);
/* [MSG1] fill the register address data */
msg = &xfer_msg[0];
msg->addr = i2c_addr;
msg->len = 1;
msg->flags = 0;
msg->buf = &buf;
/* [MSG2] fill the data rx buffer */
msg = &xfer_msg[1];
msg->addr = i2c_addr;
msg->flags = I2C_M_RD;
msg->len = 1; /* only n bytes */
msg->buf = val;
ret = i2c_transfer(twlcore->client->adapter, xfer_msg, 2);
/* i2c_transfer returns number of messages transferred */
if (ret < 0) {
pr_err("%s: failed to transfer all messages: %s\n",
__func__, strerror(-ret));
return ret;
}
return 0;
}
EXPORT_SYMBOL(twlcore_reg_read);
int twlcore_reg_write(struct twlcore *twlcore, u16 reg, u8 val)
{
int ret;
struct i2c_msg xfer_msg[1];
struct i2c_msg *msg;
int i2c_addr;
u8 buf[2];
buf[0] = reg & 0xff;
buf[1] = val;
i2c_addr = twlcore->client->addr + (reg / 0x100);
/*
* [MSG1]: fill the register address data
* fill the data Tx buffer
*/
msg = xfer_msg;
msg->addr = i2c_addr;
msg->len = 2;
msg->flags = 0;
msg->buf = buf;
/* over write the first byte of buffer with the register address */
ret = i2c_transfer(twlcore->client->adapter, xfer_msg, 1);
/* i2c_transfer returns number of messages transferred */
if (ret < 0) {
pr_err("%s: failed to transfer all messages: %s\n",
__func__, strerror(-ret));
return ret;
}
return 0;
}
EXPORT_SYMBOL(twlcore_reg_write);
int twlcore_set_bits(struct twlcore *twlcore, u16 reg, u8 mask, u8 val)
{
u8 tmp;
int ret;
ret = twlcore_reg_read(twlcore, reg, &tmp);
tmp = (tmp & ~mask) | val;
if (ret)
ret = twlcore_reg_write(twlcore, reg, tmp);
return ret;
}
EXPORT_SYMBOL(twlcore_set_bits);
static ssize_t twl_read(struct cdev *cdev, void *_buf, size_t count,
loff_t offset, ulong flags)
{
struct twlcore *priv = to_twlcore(cdev);
u8 *buf = _buf;
size_t i;
int ret;
for (i = 0; i < count; i++) {
ret = twlcore_reg_read(priv, offset, buf);
if (ret)
return (ssize_t)ret;
buf++;
offset++;
}
return count;
}
static ssize_t twl_write(struct cdev *cdev, const void *_buf, size_t count,
loff_t offset, ulong flags)
{
struct twlcore *twlcore = to_twlcore(cdev);
const u8 *buf = _buf;
size_t i;
int ret;
for (i = 0; i < count; i++) {
ret = twlcore_reg_write(twlcore, offset, *buf);
if (ret)
return (ssize_t)ret;
buf++;
offset++;
}
return count;
}
struct cdev_operations twl_fops = {
.read = twl_read,
.write = twl_write,
};
EXPORT_SYMBOL(twl_fops);
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