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

[Rajat Jain <rajatja@xxxxxxxxxx>]

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