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/*
* 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 <i2c/twl4030.h>
#define DRIVERNAME "twl4030"
#define to_twl4030(a) container_of(a, struct twl4030, cdev)
static struct twl4030 *twl_dev;
struct twl4030 *twl4030_get(void)
{
if (!twl_dev)
return NULL;
return twl_dev;
}
EXPORT_SYMBOL(twl4030_get);
int twl4030_reg_read(struct twl4030 *twl4030, 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 = twl4030->client->addr + (reg / 0x100);
/* [MSG1] fill the register address data */
msg = &xfer_msg[0];
msg->addr = i2c_addr;
msg->len = 1;
msg->flags = 0; /* Read the register value */
msg->buf = &buf;
/* [MSG2] fill the data rx buffer */
msg = &xfer_msg[1];
msg->addr = i2c_addr;
msg->flags = I2C_M_RD; /* Read the register value */
msg->len = 1; /* only n bytes */
msg->buf = val;
ret = i2c_transfer(twl4030->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(twl4030_reg_read)
int twl4030_reg_write(struct twl4030 *twl4030, 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 = twl4030->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(twl4030->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(twl4030_reg_write)
int twl4030_set_bits(struct twl4030 *twl4030, enum twl4030_reg reg, u32 mask, u32 val)
{
u32 tmp;
int err;
err = twl4030_reg_read(twl4030, reg, &tmp);
tmp = (tmp & ~mask) | val;
if (!err)
err = twl4030_reg_write(twl4030, reg, tmp);
return err;
}
EXPORT_SYMBOL(twl4030_set_bits);
static ssize_t twl_read(struct cdev *cdev, void *_buf, size_t count, ulong offset, ulong flags)
{
struct twl4030 *priv = to_twl4030(cdev);
u8 *buf = _buf;
size_t i = count;
int err;
while (i) {
err = twl4030_reg_read(priv, offset, buf);
if (err)
return (ssize_t)err;
buf++;
i--;
offset++;
}
return count;
}
static ssize_t twl_write(struct cdev *cdev, const void *_buf, size_t count, ulong offset, ulong flags)
{
struct twl4030 *twl4030 = to_twl4030(cdev);
const u8 *buf = _buf;
size_t i = count;
int err;
while (i) {
err = twl4030_reg_write(twl4030, offset, *buf);
if (err)
return (ssize_t)err;
buf++;
i--;
offset++;
}
return count;
}
static struct file_operations twl_fops = {
.lseek = dev_lseek_default,
.read = twl_read,
.write = twl_write,
};
static int twl_probe(struct device_d *dev)
{
if (twl_dev)
return -EBUSY;
twl_dev = xzalloc(sizeof(struct twl4030));
twl_dev->cdev.name = DRIVERNAME;
twl_dev->client = to_i2c_client(dev);
twl_dev->cdev.size = 1024;
twl_dev->cdev.dev = dev;
twl_dev->cdev.ops = &twl_fops;
devfs_create(&twl_dev->cdev);
return 0;
}
static struct driver_d twl_driver = {
.name = DRIVERNAME,
.probe = twl_probe,
};
static int twl_init(void)
{
register_driver(&twl_driver);
return 0;
}
device_initcall(twl_init);
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