Input: atkbd - receive and use physcode->keycode mapping from FW

Allow the firmware to specify the mapping between the scan code and the
linux keycode. This takes the form of a "linux,keymap" property which is
an array of u32 values, each value specifying mapping for a key.

Signed-off-by: Rajat Jain <rajatja@google.com>
Link: https://lore.kernel.org/r/20200427210259.91330-3-rajatja@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/keyboard/atkbd.c b/drivers/input/keyboard/atkbd.c
index 358e91f..6ec2826 100644 (file)
--- 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 SCANCODE(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.
@@ -1032,6 +1035,39 @@ static unsigned int atkbd_oqo_01plus_scancode_fixup(struct atkbd *atkbd,
        return code;
 }
 
+static int atkbd_get_keymap_from_fwnode(struct atkbd *atkbd)
+{
+       struct device *dev = &atkbd->ps2dev.serio->dev;
+       int i, n;
+       u32 *ptr;
+       u16 scancode, keycode;
+
+       /* Parse "linux,keymap" property */
+       n = device_property_count_u32(dev, "linux,keymap");
+       if (n <= 0 || n > ATKBD_KEYMAP_SIZE)
+               return -ENXIO;
+
+       ptr = kcalloc(n, sizeof(u32), GFP_KERNEL);
+       if (!ptr)
+               return -ENOMEM;
+
+       if (device_property_read_u32_array(dev, "linux,keymap", ptr, n)) {
+               dev_err(dev, "problem parsing FW keymap property\n");
+               kfree(ptr);
+               return -EINVAL;
+       }
+
+       memset(atkbd->keycode, 0, sizeof(atkbd->keycode));
+       for (i = 0; i < n; i++) {
+               scancode = SCANCODE(ptr[i]);
+               keycode = KEYCODE(ptr[i]);
+               atkbd->keycode[scancode] = keycode;
+       }
+
+       kfree(ptr);
+       return 0;
+}
+
 /*
  * atkbd_set_keycode_table() initializes keyboard's keycode table
  * according to the selected scancode set
@@ -1039,13 +1075,16 @@ static unsigned int atkbd_oqo_01plus_scancode_fixup(struct atkbd *atkbd,
 
 static void atkbd_set_keycode_table(struct atkbd *atkbd)
 {
+       struct device *dev = &atkbd->ps2dev.serio->dev;
        unsigned int scancode;
        int i, j;
 
        memset(atkbd->keycode, 0, sizeof(atkbd->keycode));
        bitmap_zero(atkbd->force_release_mask, ATKBD_KEYMAP_SIZE);
 
-       if (atkbd->translated) {
+       if (!atkbd_get_keymap_from_fwnode(atkbd)) {
+               dev_dbg(dev, "Using FW keymap\n");
+       } else if (atkbd->translated) {
                for (i = 0; i < 128; i++) {
                        scancode = atkbd_unxlate_table[i];
                        atkbd->keycode[i] = atkbd_set2_keycode[scancode];