touchpad_st: integrate power control and system state

Previously, there was a static variable "enabled" in
touchpad_power_control().  Logically, this value should be same as
"SYSTEM_STATE_ACTIVE_MODE" in system_state.  And, because system_state
will be reset after touchpad reset, to make sure everything line up, we
should get "enabled" from system_state instead.

Also, when touchpad is being reset due to errors, power control should
not enable / disable scanning.

BRANCH=nocturne
BUG=None
TEST=manual on whiskers
Signed-off-by: Wei-Han Chen <stimim@chromium.org>

Change-Id: I5485422759c68769e9ad249a2903f3f796b5b068
Reviewed-on: https://chromium-review.googlesource.com/1242576
Commit-Ready: Wei-Han Chen <stimim@chromium.org>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

1 files changed, 31 insertions, 16 deletions

diff --git a/driver/touchpad_st.c b/driver/touchpad_st.c
index ddef727fe9..cde1a07edb 100644
--- a/driver/touchpad_st.c
+++ b/driver/touchpad_st.c
@@ -45,6 +45,7 @@ static int st_tp_send_ack(void);
 static int st_tp_start_scan(void);
 static int st_tp_stop_scan(void);
 static int st_tp_update_system_state(int new_state, int mask);
+static void touchpad_power_control(void);
 
 /* Global variables */
 /*
@@ -66,6 +67,8 @@ static int tp_control;
 #define TP_CONTROL_SHALL_HALT		(1 << 0)
 #define TP_CONTROL_SHALL_RESET		(1 << 1)
 #define TP_CONTROL_SHALL_INITIALIZE	(1 << 2)
+#define TP_CONTROL_RESETTING		(1 << 3)
+#define TP_CONTROL_INITIALIZING		(1 << 4)
 
 /*
  * Number of times we have reset the touchpad because of errors.
@@ -731,6 +734,8 @@ static int st_tp_reset(void)
 /* Initialize the controller ICs after reset */
 static void st_tp_init(void)
 {
+	tp_control = TP_CONTROL_RESETTING;
+
 	if (st_tp_reset())
 		return;
 	/*
@@ -740,9 +745,9 @@ static void st_tp_init(void)
 	st_tp_read_system_info(0);
 
 	system_state = 0;
-	tp_control &= ~TP_CONTROL_SHALL_RESET;
+	tp_control &= ~TP_CONTROL_RESETTING;
 
-	st_tp_start_scan();
+	touchpad_power_control();
 }
 DECLARE_DEFERRED(st_tp_init);
 
@@ -955,11 +960,10 @@ static int st_tp_write_flash(int offset, int size, const uint8_t *data)
 	return EC_SUCCESS;
 }
 
-static int st_tp_check_command_echo(const uint8_t *cmd,
-				    const size_t len)
+static int st_tp_check_command_echo(const uint8_t *cmd, const size_t len)
 {
 	int num_events, i;
-	num_events = st_tp_read_all_events(0);
+	num_events = st_tp_read_all_events(1);
 	if (num_events < 0)
 		return -num_events;
 
@@ -969,7 +973,7 @@ static int st_tp_check_command_echo(const uint8_t *cmd,
 		if (e->evt_id == ST_TP_EVENT_ID_STATUS_REPORT &&
 		    e->report.report_type == ST_TP_STATUS_CMD_ECHO &&
 		    memcmp(e->report.info, cmd, MIN(4, len)) == 0)
-			return 0;
+			return EC_SUCCESS;
 	}
 	return -EC_ERROR_BUSY;
 }
@@ -985,7 +989,7 @@ static void st_tp_full_initialize_end(void)
 	ret = st_tp_check_command_echo(tx_buf, sizeof(tx_buf));
 	if (ret == EC_SUCCESS) {
 		CPRINTS("Full panel initialization completed.");
-		tp_control &= ~TP_CONTROL_SHALL_INITIALIZE;
+		tp_control &= ~TP_CONTROL_INITIALIZING;
 		st_tp_init();
 	} else if (ret == -EC_ERROR_BUSY) {
 		hook_call_deferred(&st_tp_full_initialize_end_data, 100 * MSEC);
@@ -998,6 +1002,10 @@ static void st_tp_full_initialize_start(void)
 {
 	uint8_t tx_buf[] = { ST_TP_CMD_WRITE_SYSTEM_COMMAND, 0x00, 0x03 };
 
+	if (tp_control == TP_CONTROL_INITIALIZING)
+		return;
+
+	tp_control = TP_CONTROL_INITIALIZING;
 	st_tp_stop_scan();
 	if (st_tp_reset())
 		return;
@@ -1116,20 +1124,29 @@ void touchpad_interrupt(enum gpio_signal signal)
 	task_wake(TASK_ID_TOUCHPAD);
 }
 
-/* Make a decision on touchpad power, based on USB and tablet mode status. */
-static void touchpad_power_control(void)
+static int touchpad_should_enable(void)
 {
-	static int enabled = 1;
-	int enable = 1;
+	/* touchpad is not ready. */
+	if (tp_control)
+		return 0;
 
 #ifdef CONFIG_USB_SUSPEND
-	enable = enable &&
-		(!usb_is_suspended() || usb_is_remote_wakeup_enabled());
+	if (usb_is_suspended() && !usb_is_remote_wakeup_enabled())
+		return 0;
 #endif
 
 #ifdef CONFIG_TABLET_MODE
-	enable = enable && !tablet_get_mode();
+	if (tablet_get_mode())
+		return 0;
 #endif
+	return 1;
+}
+
+/* Make a decision on touchpad power, based on USB and tablet mode status. */
+static void touchpad_power_control(void)
+{
+	const int enabled = !!(system_state & SYSTEM_STATE_ACTIVE_MODE);
+	int enable = touchpad_should_enable();
 
 	if (enabled == enable)
 		return;
@@ -1138,8 +1155,6 @@ static void touchpad_power_control(void)
 		st_tp_start_scan();
 	else
 		st_tp_stop_scan();
-
-	enabled = enable;
 }
 
 void touchpad_task(void *u)