diff options
Diffstat (limited to 'drivers/staging/media/atomisp/i2c/imx/otp_e2prom.c')
| -rw-r--r-- | drivers/staging/media/atomisp/i2c/imx/otp_e2prom.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/drivers/staging/media/atomisp/i2c/imx/otp_e2prom.c b/drivers/staging/media/atomisp/i2c/imx/otp_e2prom.c new file mode 100644 index 0000000..73d041f --- /dev/null +++ b/drivers/staging/media/atomisp/i2c/imx/otp_e2prom.c @@ -0,0 +1,89 @@ +/* + * 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; +} + + |
