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/*
* driver for S5C73M3 SPI
*
* Copyright (c) 2011, Samsung Electronics. All rights reserved
*
* 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.
*
* 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.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
static struct spi_device *g_spi;
static inline
int spi_xmit(const u8 *addr, const int len)
{
int ret;
struct spi_message msg;
struct spi_transfer xfer = {
.len = len,
.tx_buf = addr,
};
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
ret = spi_sync(g_spi, &msg);
if (ret < 0)
dev_err(&g_spi->dev, "%s - error %d\n",
__func__, ret);
return ret;
}
static inline
int spi_xmit_rx(u8 *in_buf, size_t len)
{
int ret;
u8 read_out_buf[2];
struct spi_message msg;
struct spi_transfer xfer = {
.tx_buf = read_out_buf,
.rx_buf = in_buf,
.len = len,
.cs_change = 0,
};
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
ret = spi_sync(g_spi, &msg);
if (ret < 0)
dev_err(&g_spi->dev, "%s - error %d\n",
__func__, ret);
return ret;
}
int s5c73m3_spi_read(u8 *buf, size_t len, const int rxSize)
{
int k;
int ret = 0;
int z = 0;
u8 paddingData[32];
u32 count = len/rxSize;
u32 extra = len%rxSize;
for (k = 0; k < count; k++) {
ret = spi_xmit_rx(&buf[rxSize*k], rxSize);
if (ret < 0)
return -EINVAL;
}
if (extra != 0) {
ret = spi_xmit_rx(&buf[rxSize*k], extra);
if (ret < 0)
return -EINVAL;
}
return 0;
}
int s5c73m3_spi_write(const u8 *addr, const int len, const int txSize)
{
int i, j = 0;
int ret = 0;
u8 paddingData[32];
u32 count = len/txSize;
u32 extra = len%txSize;
memset(paddingData, 0, sizeof(paddingData));
for (i = 0 ; i < count ; i++) {
ret = spi_xmit(&addr[j], txSize);
j += txSize;
if (ret < 0)
goto exit_err;
}
if (extra) {
ret = spi_xmit(&addr[j], extra);
if (ret < 0)
goto exit_err;
}
ret = spi_xmit(paddingData, 32);
if (ret < 0)
goto exit_err;
exit_err:
return ret;
}
static
int __devinit s5c73m3_spi_probe(struct spi_device *spi)
{
int ret;
spi->bits_per_word = 32;
if (spi_setup(spi)) {
pr_err("failed to setup spi for s5c73m3_spi\n");
ret = -EINVAL;
goto err_setup;
}
g_spi = spi;
pr_err("s5c73m3_spi successfully probed\n");
return 0;
err_setup:
return ret;
}
static
int __devexit s5c73m3_spi_remove(struct spi_device *spi)
{
return 0;
}
static
struct spi_driver s5c73m3_spi_driver = {
.driver = {
.name = "s5c73m3_spi",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = s5c73m3_spi_probe,
.remove = __devexit_p(s5c73m3_spi_remove),
};
static
int __init s5c73m3_spi_init(void)
{
int ret;
pr_err("%s\n", __func__);
ret = spi_register_driver(&s5c73m3_spi_driver);
if (ret)
pr_err("failed to register s5c73mc fw - %x\n", ret);
return ret;
}
static
void __exit s5c73m3_spi_exit(void)
{
spi_unregister_driver(&s5c73m3_spi_driver);
}
module_init(s5c73m3_spi_init);
module_exit(s5c73m3_spi_exit);
MODULE_DESCRIPTION("S5C73M3 SPI driver");
MODULE_LICENSE("GPL");
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