[U-Boot] [PATCH 10/28] i8042: Use functions to handle register access

[Bin Meng]

On Wed, Sep 9, 2015 at 12:32 PM, Simon Glass <sjg at chromium.org> wrote:
> At present the register access in kbd_reset() is quite primitive. This makes
> it hard to follow.
>
> Create functions to read and write data, both to a single register, and via
> the command/data approach.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
>  drivers/input/i8042.c | 75 ++++++++++++++++++++++++++++++---------------------
>  1 file changed, 44 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/input/i8042.c b/drivers/input/i8042.c
> index 7b95b21..dbd4b00 100644
> --- a/drivers/input/i8042.c
> +++ b/drivers/input/i8042.c
> @@ -446,53 +446,66 @@ static void kbd_conv_char(unsigned char scan_code)
>         return;
>  }
>
> -static int kbd_reset(void)
> +static int kbd_write(int reg, int value)
>  {
> -       u8 config;
> -
> -       /* controller self test */
> -       if (kbd_input_empty() == 0)
> -               return -1;
> -       out8(I8042_CMD_REG, CMD_SELF_TEST);
> -       if (kbd_output_full() == 0)
> -               return -1;
> -       if (in8(I8042_DATA_REG) != KBC_TEST_OK)
> +       if (!kbd_input_empty())
>                 return -1;
> +       out8(reg, value);
>
> -       /* keyboard reset */
> -       if (kbd_input_empty() == 0)
> +       return 0;
> +}
> +
> +static int kbd_read(int reg)
> +{
> +       if (!kbd_output_full())
>                 return -1;
> -       out8(I8042_DATA_REG, CMD_RESET_KBD);
> -       if (kbd_output_full() == 0)
> +
> +       return in8(reg);
> +}
> +
> +static int kbd_cmd_read(int cmd)
> +{
> +       if (kbd_write(I8042_CMD_REG, cmd))
>                 return -1;
> -       if (in8(I8042_DATA_REG) != KBD_ACK)
> +
> +       return kbd_read(I8042_DATA_REG);
> +}
> +
> +static int kbd_cmd_write(int cmd, int data)
> +{
> +       if (kbd_write(I8042_CMD_REG, cmd))
>                 return -1;
> -       if (kbd_output_full() == 0)
> +
> +       return kbd_write(I8042_DATA_REG, data);
> +}
> +
> +static int kbd_reset(void)
> +{
> +       int config;
> +
> +       /* controller self test */
> +       if (kbd_cmd_read(CMD_SELF_TEST) != KBC_TEST_OK)
>                 return -1;
> -       if (in8(I8042_DATA_REG) != KBD_POR)
> +
> +       /* keyboard reset */
> +       if (kbd_write(I8042_DATA_REG, CMD_RESET_KBD) ||
> +           kbd_read(I8042_DATA_REG) != KBD_ACK ||
> +           kbd_read(I8042_DATA_REG) != KBD_POR)
>                 return -1;
>
>         /* set AT translation and disable irq */
> -       if (kbd_input_empty() == 0)
> -               return -1;
> -       out8(I8042_CMD_REG, CMD_RD_CONFIG);
> -       if (kbd_output_full() == 0)
> +       config = kbd_cmd_read(CMD_RD_CONFIG);
> +       if (config == -1)
>                 return -1;
> -       config = in8(I8042_DATA_REG);
> +
>         config |= CONFIG_AT_TRANS;
>         config &= ~(CONFIG_KIRQ_EN | CONFIG_MIRQ_EN);
> -       if (kbd_input_empty() == 0)
> +       if (kbd_cmd_write(CMD_WR_CONFIG, config))
>                 return -1;
> -       out8(I8042_CMD_REG, CMD_WR_CONFIG);
> -       if (kbd_input_empty() == 0)
> -               return -1;
> -       out8(I8042_DATA_REG, config);
>
>         /* enable keyboard */
> -       if (kbd_input_empty() == 0)
> -               return -1;
> -       out8(I8042_CMD_REG, CMD_KBD_EN);
> -       if (kbd_input_empty() == 0)
> +       if (kbd_write(I8042_CMD_REG, CMD_KBD_EN) ||
> +           !kbd_input_empty())
>                 return -1;
>
>         return 0;
> --

Reviewed-by: Bin Meng <bmeng.cn at gmail.com>

Tested on Intel Crown Bay and QEMU
Tested-by: Bin Meng <bmeng.cn at gmail.com>