driver: kionix: Add software reset flow for KX022

Kionix suggests that it is recommended to issue the Software Reset
command after the device was powered. This is effective against
dynamic or non-linear behavior of a power supply or unexpected
noise above normal on the power rail during a power up.

BRANCH=eve
BUG=b:62607555
TEST=kx022:
     1. press power button 10 second to power off.
     2. power on the DUT
     3. refresh + power button to cold reboot the DUT
     4. Check the g-sensor by 'ectool motionsense'
     kxcj9:
     eve: sensor kxcj9 found.

Signed-off-by: Yidi Lin <yidi.lin@mediatek.com>
Reviewed-on: https://chromium-review.googlesource.com/536723
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
(cherry picked from commit 5a52614b8c87ab1de84c461b7bbd0b4a14dc7fdb)
 Conflict in init routine in accel_kionix.c.
 By moving WHOAMI after reset, we expect the test to work the first
 time.)
Change-Id: I362f2af59253519aa35b72cfb6b666c49e425777
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/753969

2 files changed, 95 insertions, 49 deletions

diff --git a/driver/accel_kionix.c b/driver/accel_kionix.c
index b3a1cde3ab..150a050226 100644
--- a/driver/accel_kionix.c
+++ b/driver/accel_kionix.c
@@ -513,68 +513,107 @@ static int init(const struct motion_sensor_t *s)
 	int ret, val, reg, reset_field;
 	uint8_t timeout;
 
-	/* The chip can take up to 10ms to boot */
 	mutex_lock(s->mutex);
-	reg = KIONIX_WHO_AM_I(V(s));
-	timeout = 0;
-	do {
-		msleep(1);
-		/* Read WHO_AM_I to be sure the device has booted */
-		ret = raw_read8(s->port, s->addr, reg, &val);
-		if (ret == EC_SUCCESS)
-			break;
-
-		/* Check for timeout. */
-		if (timeout++ > 20) {
-			ret = EC_ERROR_TIMEOUT;
-			break;
+	if (V(s)) {
+		/* The chip can take up to 10ms to boot */
+		reg = KIONIX_WHO_AM_I(V(s));
+		timeout = 0;
+		do {
+			msleep(1);
+			/* Read WHO_AM_I to be sure the device has booted */
+			ret = raw_read8(s->port, s->addr, reg, &val);
+			if (ret == EC_SUCCESS)
+				break;
+
+			/* Check for timeout. */
+			if (timeout++ > 20) {
+				ret = EC_ERROR_TIMEOUT;
+				break;
+			}
+		} while (1);
+	} else {
+		/* Write 0x00 to the internal register for KX022 */
+		reg = KX022_INTERNAL;
+		ret = raw_write8(s->port, s->addr, reg, 0x0);
+		if (ret != EC_SUCCESS) {
+			/*
+			 * For I2C communication, if ACK was not received
+			 * from the first address, resend the command using
+			 * the second address.
+			 */
+			if (!KIONIX_IS_SPI(s->addr)) {
+				ret = raw_write8(s->port, s->addr & ~4, reg,
+						 0x0);
+			}
 		}
-	} while (1);
-	if (ret != EC_SUCCESS) {
-		mutex_unlock(s->mutex);
-		return ret;
 	}
 
+	if (ret != EC_SUCCESS)
+		goto reset_failed;
+
+	/* Issue a software reset. */
 	reg = KIONIX_CTRL2_REG(V(s));
 	reset_field = KIONIX_RESET_FIELD(V(s));
 
-	/* Issue a software reset. */
+	if (V(s)) {
+		/* Place the sensor in standby mode to make changes. */
+		ret = disable_sensor(s, &val);
+		if (ret != EC_SUCCESS)
+			goto reset_failed;
+		ret = raw_read8(s->port, s->addr, reg, &val);
+		if (ret != EC_SUCCESS)
+			goto reset_failed;
 
-	/* Place the sensor in standby mode to make changes. */
-	ret = disable_sensor(s, &val);
-	if (ret != EC_SUCCESS) {
-		mutex_unlock(s->mutex);
-		return ret;
-	}
-	ret = raw_read8(s->port, s->addr, reg, &val);
-	if (ret != EC_SUCCESS) {
-		mutex_unlock(s->mutex);
-		return ret;
-	}
-	val |= reset_field;
-	ret = raw_write8(s->port, s->addr, reg, val);
-	if (ret != EC_SUCCESS) {
-		mutex_unlock(s->mutex);
-		return ret;
+		val |= reset_field;
+	} else {
+		/* Write 0 to CTRL2 for KX022 */
+		ret = raw_write8(s->port, s->addr, reg, 0x0);
+		if (ret != EC_SUCCESS)
+			goto reset_failed;
+
+		val = reset_field;
 	}
 
-	/* The SRST will be cleared when reset is complete. */
-	timeout = 0;
-	do {
-		msleep(1);
+	ret = raw_write8(s->port, s->addr, reg, val);
+	if (ret != EC_SUCCESS)
+		goto reset_failed;
+
+	if (V(s)) {
+		/* The SRST will be cleared when reset is complete. */
+		timeout = 0;
+		do {
+			msleep(1);
+
+			ret = raw_read8(s->port, s->addr, reg, &val);
+			/* Reset complete. */
+			if ((ret == EC_SUCCESS) && !(val & reset_field))
+				break;
+			/* Check for timeout. */
+			if (timeout++ > 20) {
+				ret = EC_ERROR_TIMEOUT;
+				goto reset_failed;
+			}
+		} while (1);
+	} else {
+		/* Wait 2 milliseconds for completion of the software reset. */
+		msleep(2);
 
+		reg = KX022_COTR;
 		ret = raw_read8(s->port, s->addr, reg, &val);
-		/* Reset complete. */
-		if ((ret == EC_SUCCESS) && !(val & reset_field))
-			break;
-
-		/* Check for timeout. */
-		if (timeout++ > 20) {
-			ret = EC_ERROR_TIMEOUT;
-			mutex_unlock(s->mutex);
-			return ret;
+		if (val != KX022_COTR_VAL_DEFAULT) {
+			CPRINTF("[%s: the software reset failed]\n", s->name);
+			ret = EC_ERROR_HW_INTERNAL;
+			goto reset_failed;
 		}
-	} while (1);
+	}
+
+	reg = KIONIX_WHO_AM_I(V(s));
+	ret = raw_read8(s->port, s->addr, reg, &val);
+	if (ret != EC_SUCCESS || val != KIONIX_WHO_AM_I_VAL(V(s))) {
+		ret = EC_ERROR_HW_INTERNAL;
+		goto reset_failed;
+	}
+
 	mutex_unlock(s->mutex);
 
 	/* Initialize with the desired parameters. */
@@ -586,6 +625,10 @@ static int init(const struct motion_sensor_t *s)
 		return ret;
 
 	return sensor_init_done(s);
+
+reset_failed:
+	mutex_unlock(s->mutex);
+	return ret;
 }
 
 const struct accelgyro_drv kionix_accel_drv = {
diff --git a/driver/accel_kx022.h b/driver/accel_kx022.h
index 7fd7508395..1192881384 100644
--- a/driver/accel_kx022.h
+++ b/driver/accel_kx022.h
@@ -30,6 +30,8 @@
 #define KX022_ZOUT_L		0x0a
 #define KX022_ZOUT_H		0x0b
 #define KX022_COTR		0x0c
+#define KX022_COTR_VAL_COTC	0xAA
+#define KX022_COTR_VAL_DEFAULT	0x55
 #define KX022_WHOAMI		0x0f
 #define KX022_TSCP		0x10
 #define KX022_TSPP		0x11
@@ -70,6 +72,7 @@
 #define KX022_BUF_CLEAR	0x3e
 #define KX022_BUF_READ		0x3f
 #define KX022_SELF_TEST	0x60
+#define KX022_INTERNAL		0x7f
 
 
 #define KX022_CNTL1_PC1		(1 << 7)