Revert "stm32: Update keyboard_scan to use run-time configuration"

This reverts commit 86a3b439b6f831e26cc588a3ed219afab36a87ad.

do not re-write the keyboard code in the released branch

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=snow
BUG=chrome-os-partner:12179
TEST=None

Change-Id: Iddc936977fe6b8cb53fe5e9f5098365d7c7c9798
Reviewed-on: https://gerrit.chromium.org/gerrit/35051
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 41 insertions, 75 deletions

diff --git a/chip/stm32/keyboard_scan.c b/chip/stm32/keyboard_scan.c
index 91c6d0b1b9..1705528a90 100644
--- a/chip/stm32/keyboard_scan.c
+++ b/chip/stm32/keyboard_scan.c
@@ -33,6 +33,9 @@ enum COL_INDEX {
 	/* 0 ~ 12 for the corresponding column */
 };
 
+#define POLLING_MODE_TIMEOUT 100000   /* 100 ms */
+#define SCAN_LOOP_DELAY 10000         /*  10 ms */
+
 /* 15:14, 12:8, 2 */
 #define IRQ_MASK 0xdf04
 
@@ -83,23 +86,6 @@ static uint32_t kb_fifo_end;			/* last entry */
 static uint32_t kb_fifo_entries;	/* number of existing entries */
 static uint8_t kb_fifo[KB_FIFO_DEPTH][KB_OUTPUTS];
 
-/*
- * Our configuration. The debounce parameters are not yet supported.
- */
-static struct ec_mkbp_config config = {
-	.valid_mask = EC_MKBP_VALID_SCAN_PERIOD | EC_MKBP_VALID_POLL_TIMEOUT |
-		EC_MKBP_VALID_MIN_POST_SCAN_DELAY |
-		EC_MKBP_VALID_OUTPUT_SETTLE | EC_MKBP_VALID_DEBOUNCE_DOWN |
-		EC_MKBP_VALID_DEBOUNCE_UP | EC_MKBP_VALID_FIFO_MAX_DEPTH,
-	.valid_flags = EC_MKBP_FLAGS_ENABLE,
-	.flags = EC_MKBP_FLAGS_ENABLE,
-	.scan_period_us = 10000,
-	.poll_timeout_us = 100 * 1000,
-	.min_post_scan_delay_us = 1000,
-	.output_settle_us = 50,
-	.fifo_max_depth = KB_FIFO_DEPTH,
-};
-
 /* clear keyboard state variables */
 void keyboard_clear_state(void)
 {
@@ -122,9 +108,8 @@ static int kb_fifo_add(uint8_t *buffp)
 {
 	int ret = EC_SUCCESS;
 
-	if (kb_fifo_entries >= config.fifo_max_depth) {
-		CPRINTF("%s: FIFO depth %d reached\n", __func__,
-			config.fifo_max_depth);
+	if (kb_fifo_entries == KB_FIFO_DEPTH) {
+		CPRINTF("%s: FIFO depth reached\n", __func__);
 		ret = EC_ERROR_OVERFLOW;
 		goto kb_fifo_push_done;
 	}
@@ -206,8 +191,8 @@ static void select_column(int col)
 	}
 }
 
-/* Set up columns so that we will get an interrupt when any key changed */
-void setup_interrupts(void)
+
+void wait_for_interrupt(void)
 {
 	uint32_t pr_before, pr_after;
 
@@ -252,7 +237,7 @@ static int check_keys_changed(void)
 
 		/* Select column, then wait a bit for it to settle */
 		select_column(c);
-		udelay(config.output_settle_us);
+		udelay(50);
 
 		r = 0;
 		tmp = STM32_GPIO_IDR(C);
@@ -377,56 +362,12 @@ int keyboard_scan_init(void)
 	return EC_SUCCESS;
 }
 
-/* Scan the keyboard until all keys are released */
-static void scan_keyboard(void)
-{
-	timestamp_t poll_deadline, start;
-	int keys_changed = 1;
-
-	mutex_lock(&scanning_enabled);
-	setup_interrupts();
-	mutex_unlock(&scanning_enabled);
-
-	/* Wait until we get an interrupt */
-	task_wait_event(-1);
-
-	enter_polling_mode();
-
-	/* Busy polling keyboard state. */
-	while (1) {
-		int wait_time;
-
-		if (!(config.flags & EC_MKBP_FLAGS_ENABLE))
-			break;
-
-		/* If we saw any keys pressed, reset deadline */
-		start = get_time();
-		if (keys_changed)
-			poll_deadline.val = start.val + config.poll_timeout_us;
-		else if (timestamp_expired(poll_deadline, &start))
-			break;
-
-		/* Scan immediately, with no delay */
-		mutex_lock(&scanning_enabled);
-		keys_changed = check_keys_changed();
-		mutex_unlock(&scanning_enabled);
-
-		/* Wait a bit before scanning again */
-		wait_time = config.scan_period_us -
-				(get_time().val - start.val);
-		if (wait_time < config.min_post_scan_delay_us)
-			wait_time = config.min_post_scan_delay_us;
-		task_wait_event(wait_time);
-	}
-	/*
-	 * TODO: (crosbug.com/p/7484) A race condition here.
-	 *       If a key state is changed here (before interrupt is
-	 *       enabled), it will be lost.
-	 */
-}
 
 void keyboard_scan_task(void)
 {
+	int key_press_timer = 0;
+	uint8_t keys_changed = 0;
+
 	/* Enable interrupts for keyboard matrix inputs */
 	gpio_enable_interrupt(GPIO_KB_IN00);
 	gpio_enable_interrupt(GPIO_KB_IN01);
@@ -438,12 +379,37 @@ void keyboard_scan_task(void)
 	gpio_enable_interrupt(GPIO_KB_IN07);
 
 	while (1) {
-		if (config.flags & EC_MKBP_FLAGS_ENABLE) {
-			scan_keyboard();
-		} else {
-			select_column(COL_TRI_STATE_ALL);
-			task_wait_event(-1);
+		mutex_lock(&scanning_enabled);
+		wait_for_interrupt();
+		mutex_unlock(&scanning_enabled);
+
+		task_wait_event(-1);
+
+		enter_polling_mode();
+		/* Busy polling keyboard state. */
+		while (1) {
+			/* sleep for debounce. */
+			usleep(SCAN_LOOP_DELAY);
+			/* Check for keys down */
+
+			mutex_lock(&scanning_enabled);
+			keys_changed = check_keys_changed();
+			mutex_unlock(&scanning_enabled);
+
+			if (keys_changed) {
+				key_press_timer = 0;
+			} else {
+				if (++key_press_timer >=
+				    (POLLING_MODE_TIMEOUT / SCAN_LOOP_DELAY)) {
+					key_press_timer = 0;
+					break;  /* exit the while loop */
+				}
+			}
 		}
+		/* TODO: (crosbug.com/p/7484) A race condition here.
+		 *       If a key state is changed here (before interrupt is
+		 *       enabled), it will be lost.
+		 */
 	}
 }