Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d832c5b2 authored by Frank Schaefer's avatar Frank Schaefer Committed by Mauro Carvalho Chehab
Browse files

[media] em28xx: add helper function for reading data blocks from i2c clients 



Add a helper function for reading data blocks from i2c devices with 8 or 16 bit
address width and 8 bit register width.
This allows us to reduce the size of new code added by the following patches.
Works only for devices with activated register auto incrementation.

Signed-off-by: default avatarFrank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 87b52439

drivers/media/usb/em28xx/em28xx-i2c.c

+46 −28
Original line number Diff line number Diff line
@@ -370,51 +370,69 @@ static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits) 
	return (hash >> (32 - bits)) & 0xffffffffUL;

}



/* Helper function to read data blocks from i2c clients with 8 or 16 bit

 * address width, 8 bit register width and auto incrementation been activated */

static int em28xx_i2c_read_block(struct em28xx *dev, u16 addr, bool addr_w16,

				 u16 len, u8 *data)

{

	int remain = len, rsize, rsize_max, ret;

	u8 buf[2];



	/* Sanity check */

	if (addr + remain > (addr_w16 * 0xff00 + 0xff + 1))

		return -EINVAL;

	/* Select address */

	buf[0] = addr >> 8;

	buf[1] = addr & 0xff;

	ret = i2c_master_send(&dev->i2c_client, buf + !addr_w16, 1 + addr_w16);

	if (ret < 0)

		return ret;

	/* Read data */

	if (dev->board.is_em2800)

		rsize_max = 4;

	else

		rsize_max = 64;

	while (remain > 0) {

		if (remain > rsize_max)

			rsize = rsize_max;

		else

			rsize = remain;



		ret = i2c_master_recv(&dev->i2c_client, data, rsize);

		if (ret < 0)

			return ret;



		remain -= rsize;

		data += rsize;

	}



	return len;

}



static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned char *eedata, int len)

{

	unsigned char buf[2], *p = eedata;

	unsigned char buf, *p = eedata;

	struct em28xx_eeprom *em_eeprom = (void *)eedata;

	int i, err, size = len, block, block_max;

	int i, err;



	dev->i2c_client.addr = 0xa0 >> 1;



	/* Check if board has eeprom */

	err = i2c_master_recv(&dev->i2c_client, buf, 0);

	err = i2c_master_recv(&dev->i2c_client, &buf, 0);

	if (err < 0) {

		em28xx_info("board has no eeprom\n");

		memset(eedata, 0, len);

		return -ENODEV;

	}



	/* Select address memory address 0x00(00) */

	buf[0] = 0;

	buf[1] = 0;

	err = i2c_master_send(&dev->i2c_client, buf, 1 + dev->eeprom_addrwidth_16bit);

	if (err != 1 + dev->eeprom_addrwidth_16bit) {

	/* Read EEPROM content */

	err = em28xx_i2c_read_block(dev, 0x0000, dev->eeprom_addrwidth_16bit,

				    len, p);

	if (err != len) {

		em28xx_errdev("failed to read eeprom (err=%d)\n", err);

		return err;

	}



	/* Read eeprom content */

	if (dev->board.is_em2800)

		block_max = 4;

	else

		block_max = 64;

	while (size > 0) {

		if (size > block_max)

			block = block_max;

		else

			block = size;



		if (block !=

		    (err = i2c_master_recv(&dev->i2c_client, p, block))) {

			em28xx_errdev("i2c eeprom read error (err=%d)\n", err);

			return err;

		}

		size -= block;

		p += block;

	}



	/* Display eeprom content */

	for (i = 0; i < len; i++) {

		if (0 == (i % 16)) {