Input: nomadik-ske-keypad - add multi key press support

Added the multi key press support for SKE keypad by modifying the irq
function for handling the two different keys on the same column and also
pressing the two different keys of different columns on the same ASR
register.
Signed-off-by: Naveen Kumar Gaddipati <naveen.gaddipati@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/nomadik-ske-keypad.c

@@ -135,12 +135,37 @@ static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
 	return 0;
 }
 
-static void ske_keypad_read_data(struct ske_keypad *keypad)
+static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
 {
+	int row = 0, code, pos;
 	struct input_dev *input = keypad->input;
-	u16 status;
-	int col = 0, row = 0, code;
-	int ske_asr, ske_ris, key_pressed, i;
+	u32 ske_ris;
+	int key_pressed;
+	int num_of_rows;
+
+	/* find out the row */
+	num_of_rows = hweight8(status);
+	do {
+		pos = __ffs(status);
+		row = pos;
+		status &= ~(1 << pos);
+
+		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
+		ske_ris = readl(keypad->reg_base + SKE_RIS);
+		key_pressed = ske_ris & SKE_KPRISA;
+
+		input_event(input, EV_MSC, MSC_SCAN, code);
+		input_report_key(input, keypad->keymap[code], key_pressed);
+		input_sync(input);
+		num_of_rows--;
+	} while (num_of_rows);
+}
+
+static void ske_keypad_read_data(struct ske_keypad *keypad)
+{
+	u8 status;
+	int col = 0;
+	int ske_asr, i;
 
 	/*
 	 * Read the auto scan registers
@@ -154,25 +179,17 @@ static void ske_keypad_read_data(struct ske_keypad *keypad)
 		if (!ske_asr)
 			continue;
 
-		/* now that ASRx is zero, find out the column x and row y*/
-		if (ske_asr & 0xff) {
+		/* now that ASRx is zero, find out the coloumn x and row y */
+		status = ske_asr & 0xff;
+		if (status) {
 			col = i * 2;
-			status = ske_asr & 0xff;
-		} else {
+			ske_keypad_report(keypad, status, col);
+		}
+		status = (ske_asr & 0xff00) >> 8;
+		if (status) {
 			col = (i * 2) + 1;
-			status = (ske_asr & 0xff00) >> 8;
+			ske_keypad_report(keypad, status, col);
 		}
-
-		/* find out the row */
-		row = __ffs(status);
-
-		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
-		ske_ris = readl(keypad->reg_base + SKE_RIS);
-		key_pressed = ske_ris & SKE_KPRISA;
-
-		input_event(input, EV_MSC, MSC_SCAN, code);
-		input_report_key(input, keypad->keymap[code], key_pressed);
-		input_sync(input);
 	}
 }
 
@@ -186,12 +203,10 @@ static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
 
 	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --retries)
-		msleep(5);
+		cpu_relax();
 
-	if (retries) {
-		/* SKEx registers are stable and can be read */
-		ske_keypad_read_data(keypad);
-	}
+	/* SKEx registers are stable and can be read */
+	ske_keypad_read_data(keypad);
 
 	/* enable auto scan interrupts */
 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);