touchpad_st: refactor to support panel initialization

After ST firmware update, there are two ways of initialization:

1. Panel initialization
2. Full panel initialization

Full panel initialization is only required if CX table format is
changed.  In the future, we will track versions of CX table format, and
only request full initialization if required.

BRANCH=nocturne
BUG=b:117203130
TEST=on whiskers
Signed-off-by: Wei-Han Chen <stimim@chromium.org>

Change-Id: I05dc2203213606addb27fd03f1c9ff937e4941f0
Reviewed-on: https://chromium-review.googlesource.com/1258691
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

1 files changed, 24 insertions, 20 deletions

diff --git a/driver/touchpad_st.c b/driver/touchpad_st.c
index e724972974..020f46f5b8 100644
--- a/driver/touchpad_st.c
+++ b/driver/touchpad_st.c
@@ -39,7 +39,7 @@ BUILD_ASSERT(sizeof(struct st_tp_event_t) == 8);
 BUILD_ASSERT(BYTES_PER_PIXEL == 1);
 
 /* Function prototypes */
-static int st_tp_full_initialize(void);
+static int st_tp_panel_init(int full);
 static int st_tp_read_all_events(int suppress_error);
 static int st_tp_read_host_buffer_header(void);
 static int st_tp_send_ack(void);
@@ -67,9 +67,10 @@ 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_SHALL_INIT		(1 << 2)
 #define TP_CONTROL_RESETTING		(1 << 3)
-#define TP_CONTROL_INITIALIZING		(1 << 4)
+#define TP_CONTROL_INIT			(1 << 4)
+#define TP_CONTROL_INIT_FULL		(1 << 5)
 
 /*
  * Number of times we have reset the touchpad because of errors.
@@ -641,7 +642,7 @@ static int st_tp_handle_error(uint8_t error_type)
 	 * Corrupted panel configuration, a full initialization should fix it.
 	 */
 	if (error_type >= 0x28 && error_type <= 0x2A) {
-		tp_control |= TP_CONTROL_SHALL_INITIALIZE;
+		tp_control |= TP_CONTROL_SHALL_INIT;
 		return 1;
 	}
 
@@ -1044,28 +1045,31 @@ static int st_tp_check_command_echo(const uint8_t *cmd, const size_t len)
 }
 
 /*
- * Perform full panel initialization.
+ * Perform panel initialization.
  *
  * This function will wait until the initialization is done, or 10 second
  * timeout is reached.
  *
+ * @param full: perform "full" panel initialization.
  * @return EC_SUCCESS or error code.
  */
-static int st_tp_full_initialize(void)
+static int st_tp_panel_init(int full)
 {
-	uint8_t tx_buf[] = { ST_TP_CMD_WRITE_SYSTEM_COMMAND, 0x00, 0x03 };
+	const uint8_t tx_buf[] = {
+		ST_TP_CMD_WRITE_SYSTEM_COMMAND, 0x00, full ? 0x03 : 0x02
+	};
 	int ret, retry;
 
-	if (tp_control == TP_CONTROL_INITIALIZING)
+	if (tp_control & (TP_CONTROL_INIT | TP_CONTROL_INIT_FULL))
 		return EC_ERROR_BUSY;
 
-	tp_control = TP_CONTROL_INITIALIZING;
+	tp_control = full ? TP_CONTROL_INIT_FULL : TP_CONTROL_INIT;
 	st_tp_stop_scan();
 	ret = st_tp_reset();
 	if (ret)
 		return ret;
 
-	CPRINTS("Start full initialization");
+	CPRINTS("Start panel initialization (full=%d)", full);
 	spi_transaction(SPI, tx_buf, sizeof(tx_buf), NULL, 0);
 
 	retry = 100;
@@ -1075,14 +1079,14 @@ static int st_tp_full_initialize(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_INITIALIZING;
+			CPRINTS("Panel initialization completed.");
+			tp_control &= ~(TP_CONTROL_INIT | TP_CONTROL_INIT_FULL);
 			st_tp_init();
 			return EC_SUCCESS;
 		} else if (ret == -EC_ERROR_BUSY) {
-			CPRINTS("Full panel initialization ongoing...");
+			CPRINTS("Panel initialization on going...");
 		} else {
-			CPRINTS("Full Panel initialization failed: %x", -ret);
+			CPRINTS("Panel initialization failed: %x", -ret);
 			return -ret;
 		}
 	}
@@ -1124,7 +1128,7 @@ int touchpad_update_write(int offset, int size, const uint8_t *data)
 	if (offset + size == CONFIG_TOUCHPAD_VIRTUAL_SIZE) {
 		CPRINTS("%s: End update, wait for reset.", __func__);
 
-		return st_tp_full_initialize();
+		return st_tp_panel_init(1);
 	}
 
 	return EC_SUCCESS;
@@ -1150,7 +1154,7 @@ int touchpad_debug(const uint8_t *param, unsigned int param_size,
 		/* no return value */
 		*data = NULL;
 		*data_size = 0;
-		st_tp_full_initialize();
+		st_tp_panel_init(1);
 		return EC_SUCCESS;
 	case ST_TP_DEBUG_CMD_START_SCAN:
 		*data = NULL;
@@ -1343,10 +1347,10 @@ void touchpad_task(void *u)
 		/*
 		 * React on touchpad errors.
 		 */
-		if (tp_control & TP_CONTROL_SHALL_INITIALIZE) {
+		if (tp_control & TP_CONTROL_SHALL_INIT) {
 			/* suppress other handlers */
-			tp_control = TP_CONTROL_SHALL_INITIALIZE;
-			st_tp_full_initialize();
+			tp_control = TP_CONTROL_SHALL_INIT;
+			st_tp_panel_init(1);
 		} else if (tp_control & TP_CONTROL_SHALL_RESET) {
 			/* suppress other handlers */
 			tp_control = TP_CONTROL_SHALL_RESET;
@@ -1711,7 +1715,7 @@ static int command_touchpad_st(int argc, char **argv)
 		st_tp_read_system_info(1);
 		return EC_SUCCESS;
 	} else if (strcasecmp(argv[1], "calibrate") == 0) {
-		st_tp_full_initialize();
+		st_tp_panel_init(1);
 		return EC_SUCCESS;
 	} else if (strcasecmp(argv[1], "enable") == 0) {
 #ifdef CONFIG_USB_ISOCHRONOUS