[U-Boot] [PATCH v2 15/28] input: Add a function to add a keycode to the existing set

[Bin Meng]

Hi Simon,

On Mon, Oct 19, 2015 at 11:17 AM, Simon Glass <sjg at chromium.org> wrote:
> Most keyboards can be scanned to produce a list of the keycodes which are
> depressed. With the i8042 keyboard this scanning is done internally and
> only the processed results are returned.
>
> In this case, when a key is pressed, a 'make' code is sent. When the key
> is released an 'unmake' code is sent. This means that the driver needs to

nits: 'unmake' -> 'break'

> keep track of which keys are pressed. It also means that any protocol error
> can lead to stuck keys.
>
> In order to support this type of keyboard, add a function when can be used
> to provide a single keycode and either add it to the list of what is pressed
> or remove it from the list. Then the normal input_send_keycodes() function
> can be used to actually do the decoding work.
>
> Add debugging to display the ASCII characters written to the input queue
> also.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---

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

>
> Changes in v2: None
>
>  drivers/input/input.c | 46 ++++++++++++++++++++++++++++++++++++++++++----
>  include/input.h       | 20 ++++++++++++++++++++
>  2 files changed, 62 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/input/input.c b/drivers/input/input.c
> index e65942e..530bf51 100644
> --- a/drivers/input/input.c
> +++ b/drivers/input/input.c
> @@ -107,6 +107,7 @@ static int input_queue_ascii(struct input_config *config, int ch)
>                         return -1; /* buffer full */
>                 config->fifo_in++;
>         }
> +       debug(" {%02x} ", ch);
>         config->fifo[config->fifo_in] = (uchar)ch;
>
>         return 0;
> @@ -394,8 +395,8 @@ static int input_keycodes_to_ascii(struct input_config *config,
>         return ch_count;
>  }
>
> -int input_send_keycodes(struct input_config *config,
> -                       int keycode[], int num_keycodes)
> +static int _input_send_keycodes(struct input_config *config, int keycode[],
> +                               int num_keycodes, bool do_send)
>  {
>         char ch[num_keycodes * ANSI_CHAR_MAX];
>         int count, i, same = 0;
> @@ -420,8 +421,10 @@ int input_send_keycodes(struct input_config *config,
>
>         count = input_keycodes_to_ascii(config, keycode, num_keycodes,
>                                         ch, sizeof(ch), is_repeat ? 0 : same);
> -       for (i = 0; i < count; i++)
> -               input_queue_ascii(config, ch[i]);
> +       if (do_send) {
> +               for (i = 0; i < count; i++)
> +                       input_queue_ascii(config, ch[i]);
> +       }
>         delay_ms = is_repeat ?
>                         config->repeat_rate_ms :
>                         config->repeat_delay_ms;
> @@ -431,6 +434,41 @@ int input_send_keycodes(struct input_config *config,
>         return count;
>  }
>
> +int input_send_keycodes(struct input_config *config, int keycode[],
> +                       int num_keycodes)
> +{
> +       return _input_send_keycodes(config, keycode, num_keycodes, true);
> +}
> +
> +int input_add_keycode(struct input_config *config, int new_keycode,
> +                     bool release)
> +{
> +       int keycode[INPUT_MAX_MODIFIERS + 1];
> +       int count, i;
> +
> +       /* Add the old keycodes which are not removed by this new one */
> +       for (i = 0, count = 0; i < config->num_prev_keycodes; i++) {
> +               int code = config->prev_keycodes[i];
> +
> +               if (new_keycode == code) {
> +                       if (release)
> +                               continue;
> +                       new_keycode = -1;
> +               }
> +               keycode[count++] = code;
> +       }
> +
> +       if (!release && new_keycode != -1)
> +               keycode[count++] = new_keycode;
> +       debug("\ncodes for %02x/%d: ", new_keycode, release);
> +       for (i = 0; i < count; i++)
> +               debug("%02x ", keycode[i]);
> +       debug("\n");
> +
> +       /* Don't output any ASCII characters if this is a key release */
> +       return _input_send_keycodes(config, keycode, count, !release);
> +}
> +
>  int input_add_table(struct input_config *config, int left_keycode,
>                     int right_keycode, const uchar *xlate, int num_entries)
>  {
> diff --git a/include/input.h b/include/input.h
> index 71f3538..9942d6f 100644
> --- a/include/input.h
> +++ b/include/input.h
> @@ -76,6 +76,26 @@ struct stdio_dev;
>  int input_send_keycodes(struct input_config *config, int keycode[], int count);
>
>  /**
> + * Add a new keycode to an existing list of keycodes
> + *
> + * This can be used to handle keyboards which do their own scanning. An
> + * internal list of depressed keys is maintained by the input library. Then
> + * this function is called to add a new key to the list (when a 'make code' is
> + * received), or remove a key (when a 'break code' is received).
> + *
> + * This function looks after maintenance of the list of active keys, and calls
> + * input_send_keycodes() with its updated list.
> + *
> + * @param config       Input state
> + * @param new_keycode  New keycode to add/remove
> + * @param release      true if this key was released, false if depressed
> + * @return number of ascii characters sent, or 0 if none, or -1 for an
> + *     internal error
> + */
> +int input_add_keycode(struct input_config *config, int new_keycode,
> +                     bool release);
> +
> +/**
>   * Add a new key translation table to the input
>   *
>   * @param config       Input state
> --

Regards,
Bin