[U-Boot] [PATCH v3 1/2] i2c: sh_i2c: bugfix: i2c probe command does not work

[Nobuhiro Iwamatsu]

Applied, thanks for your this fix!

Best regards,
  Nobuhiro

2014-04-14 17:13 GMT+09:00 Tetsuyuki Kobayashi <koba at kmckk.co.jp>:
> This is regression of commit 2035d77d i2c: sh_i2c: Update to new CONFIG_SYS_I2C framework
>
> Before commit 2035d77d, i2c probe command works properly on kzm9g board.
>
> KZM-A9-GT# i2c probe
> Valid chip addresses: 0C 12 1D 32 39 3D 40 60
>
> After commit 2035d77d, i2c probe command does not work.
>
> KZM-A9-GT# i2c probe
> Valid chip addresses: 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F
>
> sh_i2c_probe() calls sh_i2c_read(), but read length is 0. So acutally it does not read device at all. This patch prepares dummy buffer and read data into it.
>
> Signed-off-by: Tetsuyuki Kobayashi <koba at kmckk.co.jp>
> ---
> Changes for v2:
>   - correct typo in commit message.
>
> Changes for v3:
>   - prepare dummy data buffer and use it to avoid NULL access.
>
>  drivers/i2c/sh_i2c.c |    4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/sh_i2c.c b/drivers/i2c/sh_i2c.c
> index cc19100..e7e9692 100644
> --- a/drivers/i2c/sh_i2c.c
> +++ b/drivers/i2c/sh_i2c.c
> @@ -269,7 +269,9 @@ static int sh_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
>  static int
>  sh_i2c_probe(struct i2c_adapter *adap, u8 dev)
>  {
> -       return sh_i2c_read(adap, dev, 0, 0, NULL, 0);
> +       u8 dummy[1];
> +
> +       return sh_i2c_read(adap, dev, 0, 0, dummy, sizeof dummy);
>  }
>
>  static unsigned int sh_i2c_set_bus_speed(struct i2c_adapter *adap,
> --
> 1.7.9.5
>



-- 
Nobuhiro Iwamatsu
   iwamatsu at {nigauri.org / debian.org}
   GPG ID: 40AD1FA6