Re: [PATCH v6 2/2] input: joystick: driver for Adafruit Seesaw Gamepad

Oct 31, 2023 03:10:50 Anshul Dalal [off-list ref]:

Hello Thomas,

Thanks for the review! The requested changes will be addressed in the
next patch version though I had a few comments below:

On 10/27/23 11:44, Thomas Weißschuh wrote:

quoted

Hi Anshul,

thanks for the reworks!

Some more comments inline.

On 2023-10-27 10:48:11+0530, Anshul Dalal wrote:

[..]

quoted

quoted

+struct seesaw_button_description {
+   unsigned int code;
+   unsigned int bit;
+};
+
+static const struct seesaw_button_description seesaw_buttons[] = {
+   {
+       .code = BTN_EAST,
+       .bit = SEESAW_BUTTON_A,
+   },
+   {
+       .code = BTN_SOUTH,
+       .bit = SEESAW_BUTTON_B,
+   },
+   {
+       .code = BTN_NORTH,
+       .bit = SEESAW_BUTTON_X,
+   },
+   {
+       .code = BTN_WEST,
+       .bit = SEESAW_BUTTON_Y,
+   },
+   {
+       .code = BTN_START,
+       .bit = SEESAW_BUTTON_START,
+   },
+   {
+       .code = BTN_SELECT,
+       .bit = SEESAW_BUTTON_SELECT,
+   },
+};

This looks very much like a sparse keymap which can be implemented with
the helpers from <linux/input/sparse-keymap.h>.

When going through the API provided by sparse-keymap, I could only see
the use for sparse_keymap_report_entry here. Which leads to the
following refactored code:

static const struct key_entry seesaw_buttons_new[] = {
    {KE_KEY, SEESAW_BUTTON_A, {BTN_SOUTH}},
    {KE_KEY, SEESAW_BUTTON_B, {BTN_EAST}},

No braces I think.

    ...
};

for (i = 0; i < ARRAY_SIZE(seesaw_buttons_new); i++) {
    sparse_keymap_report_entry(input, &seesaw_buttons_new[i],
        data.button_state & BIT(seesaw_buttons_new[i].code),
        false);
}

I don't think this significantly improves the code unless you had some
other way to use the API in mind.

I thought about sparse_keymap_setup() and sparse_keymap_report_event().

It does not significantly change the code but would be a standard API.

Thomas