driver: tcs3400: Check for device status only once

Since ASIEN (interrupt on ALS saturation) and ALS threshold interrupts
are disabled, we can only get interrupt on RBGC cycle read.

Therefore, when using the interrupt, not need to check if RGB data is
ready in post_events(). Only check while in force mode.
Remove recheck when accounting for saturation.

BUG=b:177860358
BRANCH=kukui,hatch,puff,volteer
TEST=compile

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Change-Id: I7fc419a98828b9b188849e04a15cfefaf9e96c8a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2572739
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>

1 files changed, 31 insertions, 28 deletions

diff --git a/driver/als_tcs3400.c b/driver/als_tcs3400.c
index fa4a665df9..4de2bf2c61 100644
--- a/driver/als_tcs3400.c
+++ b/driver/als_tcs3400.c
@@ -156,7 +156,8 @@ static int tcs3400_rgb_read(const struct motion_sensor_t *s, intv3_t v)
 static int
 tcs3400_adjust_sensor_for_saturation(struct motion_sensor_t *s,
 				     uint16_t cur_lux,
-				     uint16_t *crgb_data)
+				     uint16_t *crgb_data,
+				     uint32_t status)
 {
 	struct tcs_saturation_t *sat_p =
 			&TCS3400_RGB_DRV_DATA(s+1)->saturation;
@@ -164,14 +165,9 @@ tcs3400_adjust_sensor_for_saturation(struct motion_sensor_t *s,
 	const uint8_t save_atime = sat_p->atime;
 	uint16_t max_val =  0;
 	int ret;
-	int status = 0;
 	int percent_left = 0;
 
 	/* Adjust for saturation if needed */
-	ret = tcs3400_i2c_read8(s, TCS_I2C_STATUS, &status);
-	if (ret)
-		return ret;
-
 	if (!(status & TCS_I2C_STATUS_RGBC_VALID))
 		return EC_SUCCESS;
 
@@ -382,7 +378,9 @@ static bool is_spoof(struct motion_sensor_t *s)
 	       (s->flags & MOTIONSENSE_FLAG_IN_SPOOF_MODE);
 }
 
-static int tcs3400_post_events(struct motion_sensor_t *s, uint32_t last_ts)
+static int tcs3400_post_events(struct motion_sensor_t *s,
+			       uint32_t last_ts,
+			       uint32_t status)
 {
 	/*
 	 * Rule says RGB sensor is right after ALS sensor.
@@ -396,22 +394,29 @@ static int tcs3400_post_events(struct motion_sensor_t *s, uint32_t last_ts)
 	int32_t xyz_data[3] = { 0, 0, 0 };
 	uint16_t raw_data[CRGB_COUNT]; /* holds raw CRGB assembled from buf[] */
 	int *last_v;
-	int32_t lux, data = 0;
-	int i, ret;
+	int32_t lux = 0;
+	int ret;
 
-	i = 20;	/* 400ms max */
-	while (i--) {
-		/* Make sure data is valid */
-		ret = tcs3400_i2c_read8(s, TCS_I2C_STATUS, &data);
-		if (ret)
-			return ret;
-		if (data & TCS_I2C_STATUS_RGBC_VALID)
-			break;
-		msleep(20);
-	}
-	if (i < 0) {
-		CPRINTS("RGBC invalid (0x%x)", data);
-		return EC_ERROR_UNCHANGED;
+	if (IS_ENABLED(CONFIG_ALS_TCS3400_EMULATED_IRQ_EVENT)) {
+		int i = 5;	/* 100ms max */
+
+		while (i--) {
+			/* Make sure data is valid */
+			if (status & TCS_I2C_STATUS_RGBC_VALID)
+				break;
+			msleep(20);
+			/*
+			 * When not in interrupt mode, we could have scheduled
+			 * the handler too early.
+			 */
+			ret = tcs3400_i2c_read8(s, TCS_I2C_STATUS, &status);
+			if (ret)
+				return ret;
+		}
+		if (i < 0) {
+			CPRINTS("RGBC invalid (0x%x)", status);
+			return EC_ERROR_UNCHANGED;
+		}
 	}
 
 	/* Read the light registers */
@@ -481,7 +486,7 @@ static int tcs3400_post_events(struct motion_sensor_t *s, uint32_t last_ts)
 
 	if (!is_calibration)
 		ret = tcs3400_adjust_sensor_for_saturation(s, xyz_data[Y],
-							   raw_data);
+							   raw_data, status);
 
 	return ret;
 }
@@ -506,7 +511,7 @@ void tcs3400_interrupt(enum gpio_signal signal)
  */
 static int tcs3400_irq_handler(struct motion_sensor_t *s, uint32_t *event)
 {
-	int status = 0;
+	uint32_t status = 0;
 	int ret = EC_SUCCESS;
 
 	if (!(*event & CONFIG_ALS_TCS3400_INT_EVENT))
@@ -522,10 +527,8 @@ static int tcs3400_irq_handler(struct motion_sensor_t *s, uint32_t *event)
 		return ret;
 
 	if ((status & TCS_I2C_STATUS_RGBC_VALID) ||
-			((status & TCS_I2C_STATUS_ALS_IRQ) &&
-			(status & TCS_I2C_STATUS_ALS_SATURATED)) ||
-			IS_ENABLED(CONFIG_ALS_TCS3400_EMULATED_IRQ_EVENT)) {
-		ret = tcs3400_post_events(s, last_interrupt_timestamp);
+	    IS_ENABLED(CONFIG_ALS_TCS3400_EMULATED_IRQ_EVENT)) {
+		ret = tcs3400_post_events(s, last_interrupt_timestamp, status);
 		if (ret)
 			return ret;
 	}