[U-Boot,v2,6/9] i2c: sh_i2c.c: check error in i2c_read and i2c_write

Before this patch, i2c_{read,write} always returned 0.
Check TACK in i2c_raw_{read,write} so that i2c_{read,write} return non-zero when error.

Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
---
Changes for v2:
 - new

 drivers/i2c/sh_i2c.c |   44 ++++++++++++++++++++++++++++----------------
 1 file changed, 28 insertions(+), 16 deletions(-)

On Wed, Sep 12, 2012 at 5:21 PM, Tetsuyuki Kobayashi <koba@kmckk.co.jp> wrote:
> Before this patch, i2c_{read,write} always returned 0.
> Check TACK in i2c_raw_{read,write} so that i2c_{read,write} return non-zero when error.
>
> Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
> ---
> Changes for v2:
>  - new
>
>  drivers/i2c/sh_i2c.c |   44 ++++++++++++++++++++++++++++----------------
>  1 file changed, 28 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/i2c/sh_i2c.c b/drivers/i2c/sh_i2c.c
> index 25dbc43..e3ee804 100644
> --- a/drivers/i2c/sh_i2c.c
> +++ b/drivers/i2c/sh_i2c.c
> @@ -151,29 +151,35 @@ static void i2c_finish(struct sh_i2c *base)
>         writeb(readb(&base->iccr) & ~SH_I2C_ICCR_ICE, &base->iccr);
>  }
>
> -static void i2c_raw_write(struct sh_i2c *base, u8 id, u8 reg, u8 val)
> +static int i2c_raw_write(struct sh_i2c *base, u8 id, u8 reg, u8 val)
>  {
> -       i2c_set_addr(base, id, reg, 0);
> +       if (i2c_set_addr(base, id, reg, 0) != 0)
> +               return -1;
>         udelay(10);
>
>         writeb(val, &base->icdr);
> -       irq_dte(base);
> +       if (irq_dte_with_tack(base) != 0)
> +               return -1;
>
>         writeb((SH_I2C_ICCR_ICE | SH_I2C_ICCR_RTS), &base->iccr);
> -       irq_dte(base);
> +       if (irq_dte_with_tack(base) != 0)
> +               return -1;
>         irq_busy(base);
>
>         i2c_finish(base);
> +       return 0;
>  }
>
> -static u8 i2c_raw_read(struct sh_i2c *base, u8 id, u8 reg)
> +static int i2c_raw_read(struct sh_i2c *base, u8 id, u8 reg)
>  {
> -       u8 ret;
> +       int ret;
>
>  #if defined(CONFIG_SH73A0)
> -       i2c_set_addr(base, id, reg, 0);
> +       if (i2c_set_addr(base, id, reg, 0) != 0)
> +               return -1;
>  #else
> -       i2c_set_addr(base, id, reg, 1);
> +       if (i2c_set_addr(base, id, reg, 1) != 0)
> +               return -1;
>         udelay(100);
>  #endif
>
> @@ -181,12 +187,14 @@ static u8 i2c_raw_read(struct sh_i2c *base, u8 id, u8 reg)
>         irq_dte(base);
>
>         writeb(id << 1 | 0x01, &base->icdr);
> -       irq_dte(base);
> +       if (irq_dte_with_tack(base) != 0)
> +               return -1;
>
>         writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_SCP), &base->iccr);
> -       irq_dte(base);
> +       if (irq_dte_with_tack(base) != 0)
> +               return -1;
>
> -       ret = readb(&base->icdr);
> +       ret = readb(&base->icdr) & 0xff;
>
>         writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RACK), &base->iccr);
>         readb(&base->icdr); /* Dummy read */
> @@ -303,10 +311,14 @@ void i2c_init(int speed, int slaveaddr)
>   */
>  int i2c_read(u8 chip, u32 addr, int alen, u8 *buffer, int len)
>  {
> +       int ret;
>         int i = 0;
> -       for (i = 0 ; i < len ; i++)
> -               buffer[i] = i2c_raw_read(base, chip, addr + i);
> -
> +       for (i = 0 ; i < len ; i++) {
> +               ret = i2c_raw_read(base, chip, addr + i);
> +               if (ret < 0)
> +                       return -1;
> +               buffer[i] = ret & 0xff;
> +       }
>         return 0;
>  }
>
> @@ -327,8 +339,8 @@ int i2c_write(u8 chip, u32 addr, int alen, u8 *buffer, int len)
>  {
>         int i = 0;
>         for (i = 0; i < len ; i++)
> -               i2c_raw_write(base, chip, addr + i, buffer[i]);
> -
> +               if (i2c_raw_write(base, chip, addr + i, buffer[i]) != 0)
> +                       return -1;
>         return 0;
>  }
>
> --
> 1.7.9.5
>

Acked-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>

Best regards,
  Nobuhiro