Re: [PATCH v2 4/5] Input: atkbd: Receive and use physcode->keycode mapping from FW

Dmitry Torokhov
2020-03-26T21:20:32Z

Hi Rajat,

On Tue, Mar 24, 2020 at 05:35:17AM -0700, Rajat Jain wrote:
> Allow the firmware to specify the mapping between the physical
> code and the linux keycode. This takes the form of a "keymap"
> property which is an array of u32 values, each value specifying
> mapping for a key.
>
> Signed-off-by: Rajat Jain <rajatja@google.com>
> ---
> v2: Remove the Change-Id from the commit log
>
> drivers/input/keyboard/atkbd.c | 39 ++++++++++++++++++++++++++++++++--
> 1 file changed, 37 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/keyboard/atkbd.c b/drivers/input/keyboard/atkbd.c
> index 7623eebef2593..c8017a5707581 100644
> --- a/drivers/input/keyboard/atkbd.c
> +++ b/drivers/input/keyboard/atkbd.c
> @@ -66,6 +66,9 @@ MODULE_PARM_DESC(terminal, "Enable break codes on an IBM Terminal keyboard conne
>
> #define MAX_FUNCTION_ROW_KEYS 24
>
> +#define PHYSCODE(keymap) ((keymap >> 16) & 0xFFFF)
> +#define KEYCODE(keymap) (keymap & 0xFFFF)
> +
> /*
> * Scancode to keycode tables. These are just the default setting, and
> * are loadable via a userland utility.
> @@ -236,6 +239,9 @@ struct atkbd {
>
> u16 function_row_physmap[MAX_FUNCTION_ROW_KEYS];
> int num_function_row_keys;
> +
> + unsigned short fw_keymap[ATKBD_KEYMAP_SIZE];
> + bool use_fw_keymap;

Why do we need to keep firmware-provided keymap in atkbd instance? It is
not going anywhere and can be accessed via device_property_* API
whenever we decide to refresh the keymap.

> };
>
> /*
> @@ -1045,7 +1051,10 @@ static void atkbd_set_keycode_table(struct atkbd *atkbd)
> memset(atkbd->keycode, 0, sizeof(atkbd->keycode));
> bitmap_zero(atkbd->force_release_mask, ATKBD_KEYMAP_SIZE);
>
> - if (atkbd->translated) {
> + if (atkbd->use_fw_keymap) {
> + memcpy(atkbd->keycode, atkbd->fw_keymap,
> + sizeof(atkbd->keycode));
> + } else if (atkbd->translated) {
> for (i = 0; i < 128; i++) {
> scancode = atkbd_unxlate_table[i];
> atkbd->keycode[i] = atkbd_set2_keycode[scancode];
> @@ -1163,7 +1172,9 @@ static void atkbd_parse_fwnode_data(struct serio *serio)
> {
> struct atkbd *atkbd = serio_get_drvdata(serio);
> struct device *dev = &serio->dev;
> - int n;
> + int i, n;
> + u32 *ptr;
> + u16 physcode, keycode;
>
> if (!dev_fwnode(dev))
> return;
> @@ -1176,6 +1187,30 @@ static void atkbd_parse_fwnode_data(struct serio *serio)
> atkbd->num_function_row_keys = n;
> dev_info(dev, "FW reported %d function-row key locations\n", n);
> }
> +
> + /* Parse "keymap" property */
> + n = device_property_count_u32(dev, "keymap");
> + if (n > 0 && n <= ATKBD_KEYMAP_SIZE) {
> +
> + ptr = kcalloc(n, sizeof(u32), GFP_KERNEL);
> + if (!ptr)
> + return;
> +
> + if (device_property_read_u32_array(dev, "keymap", ptr, n)) {
> + dev_err(dev, "problem parsing FW keymap property\n");
> + kfree(ptr);
> + return;
> + }
> +
> + for (i = 0; i < n; i++) {
> + physcode = PHYSCODE(ptr[i]);
> + keycode = KEYCODE(ptr[i]);
> + atkbd->fw_keymap[physcode] = keycode;
> + }
> + dev_info(dev, "Using FW keymap (%d keys)\n", n);

This should be dev_dbg().

> + atkbd->use_fw_keymap = true;
> + kfree(ptr);
> + }
> }
>
> /*
> --
> 2.25.1.696.g5e7596f4ac-goog
>

Thanks.

--
Dmitry