linux/include/media/ov_16bit_addr_reg_helpers.h
Hans de Goede 65b3974173 media: core: add ov_16bit_addr_reg_helpers.h
The following drivers under drivers/media/i2c: ov08x40.c, ov13858.c,
ov13b10.c, ov2680.c, ov2685.c, ov2740.c, ov4689.c, ov5670.c,
ov5675.c, ov5695.c, ov8856.c, ov9282.c and ov9734.c,

as well as various "atomisp" sensor drivers in drivers/staging, *all*
use register access helpers with the following function prototypes:

int ovxxxx_read_reg(struct ovxxxx_dev *sensor, u16 reg,
                    unsigned int len, u32 *val);

int ovxxxx_write_reg(struct ovxxxx_dev *sensor, u16 reg,
                     unsigned int len, u32 val);

To read/write registers on Omnivision OVxxxx image sensors wich expect
a 16 bit register address in big-endian format and which have 1-3 byte
wide registers, in big-endian format (for the higher width registers).

Add a new ov_16bit_addr_reg_helpers.h header file with static inline
versions of these register access helpers, so that this code duplication
can be removed.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
2023-02-08 08:23:50 +01:00

93 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* I2C register access helpers for Omnivision OVxxxx image sensors which expect
* a 16 bit register address in big-endian format and which have 1-3 byte
* wide registers, in big-endian format (for the higher width registers).
*
* Based on the register helpers from drivers/media/i2c/ov2680.c which is:
* Copyright (C) 2018 Linaro Ltd
*/
#ifndef __OV_16BIT_ADDR_REG_HELPERS_H
#define __OV_16BIT_ADDR_REG_HELPERS_H
#include <asm/unaligned.h>
#include <linux/dev_printk.h>
#include <linux/i2c.h>
static inline int ov_read_reg(struct i2c_client *client, u16 reg,
unsigned int len, u32 *val)
{
u8 addr_buf[2], data_buf[4] = { };
struct i2c_msg msgs[2];
int ret;
if (len > 4)
return -EINVAL;
put_unaligned_be16(reg, addr_buf);
msgs[0].addr = client->addr;
msgs[0].flags = 0;
msgs[0].len = ARRAY_SIZE(addr_buf);
msgs[0].buf = addr_buf;
msgs[1].addr = client->addr;
msgs[1].flags = I2C_M_RD;
msgs[1].len = len;
msgs[1].buf = &data_buf[4 - len];
ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (ret != ARRAY_SIZE(msgs)) {
dev_err(&client->dev, "read error: reg=0x%4x: %d\n", reg, ret);
return -EIO;
}
*val = get_unaligned_be32(data_buf);
return 0;
}
#define ov_read_reg8(s, r, v) ov_read_reg(s, r, 1, v)
#define ov_read_reg16(s, r, v) ov_read_reg(s, r, 2, v)
#define ov_read_reg24(s, r, v) ov_read_reg(s, r, 3, v)
static inline int ov_write_reg(struct i2c_client *client, u16 reg,
unsigned int len, u32 val)
{
u8 buf[6];
int ret;
if (len > 4)
return -EINVAL;
put_unaligned_be16(reg, buf);
put_unaligned_be32(val << (8 * (4 - len)), buf + 2);
ret = i2c_master_send(client, buf, len + 2);
if (ret != len + 2) {
dev_err(&client->dev, "write error: reg=0x%4x: %d\n", reg, ret);
return -EIO;
}
return 0;
}
#define ov_write_reg8(s, r, v) ov_write_reg(s, r, 1, v)
#define ov_write_reg16(s, r, v) ov_write_reg(s, r, 2, v)
#define ov_write_reg24(s, r, v) ov_write_reg(s, r, 3, v)
static inline int ov_update_reg(struct i2c_client *client, u16 reg, u8 mask, u8 val)
{
u32 readval;
int ret;
ret = ov_read_reg8(client, reg, &readval);
if (ret < 0)
return ret;
val = (readval & ~mask) | (val & mask);
return ov_write_reg8(client, reg, val);
}
#endif