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/*
* Copyright (c) 2013 Intel Corporation. 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.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
*/
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/types.h>
#include <media/v4l2-device.h>
#include "common.h"
/*
* Read EEPROM data from the gerneral e2prom chip(eg.
* CAT24C08, CAT24C128, le24l042cs, and store
* it into a kmalloced buffer. On error return NULL.
* @size: set to the size of the returned EEPROM data.
*/
void *e2prom_otp_read(struct v4l2_subdev *sd, u8 dev_addr,
u32 start_addr, u32 size)
{
struct i2c_client *client = v4l2_get_subdevdata(sd);
unsigned int e2prom_i2c_addr = dev_addr >> 1;
static const unsigned int max_read_size = 30;
int addr;
u32 s_addr = start_addr & E2PROM_ADDR_MASK;
bool two_addr = (start_addr & E2PROM_2ADDR) >> 31;
char *buffer;
buffer = devm_kzalloc(&client->dev, size, GFP_KERNEL);
if (!buffer)
return NULL;
for (addr = s_addr; addr < size; addr += max_read_size) {
struct i2c_msg msg[2];
unsigned int i2c_addr = e2prom_i2c_addr;
u16 addr_buf;
int r;
msg[0].flags = 0;
if (two_addr) {
msg[0].addr = i2c_addr;
addr_buf = cpu_to_be16(addr & 0xFFFF);
msg[0].len = 2;
msg[0].buf = (u8 *)&addr_buf;
} else {
i2c_addr |= (addr >> 8) & 0x7;
msg[0].addr = i2c_addr;
addr_buf = addr & 0xFF;
msg[0].len = 1;
msg[0].buf = (u8 *)&addr_buf;
}
msg[1].addr = i2c_addr;
msg[1].flags = I2C_M_RD;
msg[1].len = min(max_read_size, size - addr);
msg[1].buf = &buffer[addr];
r = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
if (r != ARRAY_SIZE(msg)) {
dev_err(&client->dev, "read failed at 0x%03x\n", addr);
return NULL;
}
}
return buffer;
}
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