target/linux/bcm27xx/patches-5.15/950-0240-media-irs1125-Using-i2c_transfer-for-ic2-reads.patch

   1 From 26c02ccf6302ec39a6fb344de0fe2d6cbda5d655 Mon Sep 17 00:00:00 2001
   2 From: Markus Proeller <markus.proeller@pieye.org>
   3 Date: Tue, 16 Jun 2020 13:24:31 +0200
   4 Subject: [PATCH] media: irs1125: Using i2c_transfer for ic2 reads
   5
   6 Reading data over i2c is done by using i2c_transfer to ensure that this
   7 operation can't be interrupted.
   8
   9 Signed-off-by: Markus Proeller <markus.proeller@pieye.org>
  10 ---
  11  drivers/media/i2c/irs1125.c | 37 ++++++++++++++++++++++---------------
  12  1 file changed, 22 insertions(+), 15 deletions(-)
  13
  14 --- a/drivers/media/i2c/irs1125.c
  15 +++ b/drivers/media/i2c/irs1125.c
  16 @@ -248,27 +248,34 @@ static int irs1125_write(struct v4l2_sub
  17
  18  static int irs1125_read(struct v4l2_subdev *sd, u16 reg, u16 *val)
  19  {
  20 -       int ret;
  21 -       unsigned char data_w[2] = { reg >> 8, reg & 0xff };
  22 -       char rdval[2];
  23 -
  24         struct i2c_client *client = v4l2_get_subdevdata(sd);
  25 +       struct i2c_msg msgs[2];
  26 +       u8 addr_buf[2] = { reg >> 8, reg & 0xff };
  27 +       u8 data_buf[2] = { 0, };
  28 +       int ret;
  29
  30 -       ret = i2c_master_send(client, data_w, 2);
  31 -       if (ret < 0) {
  32 -               dev_dbg(&client->dev, "%s: i2c write error, reg: %x\n",
  33 -                       __func__, reg);
  34 +       /* Write register address */
  35 +       msgs[0].addr = client->addr;
  36 +       msgs[0].flags = 0;
  37 +       msgs[0].len = ARRAY_SIZE(addr_buf);
  38 +       msgs[0].buf = addr_buf;
  39 +
  40 +       /* Read data from register */
  41 +       msgs[1].addr = client->addr;
  42 +       msgs[1].flags = I2C_M_RD;
  43 +       msgs[1].len = 2;
  44 +       msgs[1].buf = data_buf;
  45 +
  46 +       ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
  47 +       if (ret != ARRAY_SIZE(msgs)) {
  48 +               if (ret >= 0)
  49 +                       ret = -EIO;
  50                 return ret;
  51         }
  52
  53 -       ret = i2c_master_recv(client, rdval, 2);
  54 -       if (ret < 0)
  55 -               dev_err(&client->dev, "%s: i2c read error, reg: %x\n",
  56 -                       __func__, reg);
  57 -
  58 -       *val = rdval[1] | (rdval[0] << 8);
  59 +       *val = data_buf[1] | (data_buf[0] << 8);
  60
  61 -       return ret;
  62 +       return 0;
  63  }
  64
  65  static int irs1125_write_array(struct v4l2_subdev *sd,