mcdp28x0: Use custom appstest command for get_info

Firmware's original get_info command always returns the same values
for family, chipid, irom & fw despite indeed having different
versions.

Currently its:
  family:000e chipid:0001 irom:1.0.0 fw:0.0.0

As we have a new stepping of the chip ('BB') and a corresponding new
firmware (>=0.74) we need a mechanism to verify and log this change.

CL uses the newly hatched appstest command (0x12) message 0x28 to
surface information that properly reflects both hardware and firmware
running.

Signed-off-by: Todd Broch <tbroch@chromium.org>

BRANCH=samus
BUG=chrome-os-partner:35939
TEST=manual,

For devices running 0.54 | 0.74 fw see gpio MCDP_READY asserted.

With CONFIG_CMD_MCDP in board/hoho/board.h see the following responses
when executing 'mcdp info'

Stepping | FW   | Response
--------------------------------------------------------------------
'BA'       0.53   fails as expected
'BA'       0.54   family:0010 chipid:2850 irom:2.0.0 fw:0.54.0
'BB'       0.73   fails as expected
'BB'       0.74   family:0010 chipid:2850 irom:2.1.0 fw:0.74.0

Change-Id: I2c36393a298c617f903389dab24da631b60ec574
Reviewed-on: https://chromium-review.googlesource.com/274049
Reviewed-by: Scott Collyer <scollyer@chromium.org>
Commit-Queue: Todd Broch <tbroch@chromium.org>
Tested-by: Todd Broch <tbroch@chromium.org>

2 files changed, 18 insertions, 15 deletions

diff --git a/board/hoho/board.c b/board/hoho/board.c
index 8e0a370bf3..56484bc0a7 100644
--- a/board/hoho/board.c
+++ b/board/hoho/board.c
@@ -141,8 +141,8 @@ static void factory_validation_deferred(void)
 	mcdp_enable();
 
 	/* test mcdp via serial to validate function */
-	if (!mcdp_get_info(&info) && (MCDP_FAMILY(info.family) == 0xe) &&
-	    (MCDP_CHIPID(info.chipid) == 0x1)) {
+	if (!mcdp_get_info(&info) && (MCDP_FAMILY(info.family) == 0x0010) &&
+	(MCDP_CHIPID(info.chipid) == 0x2850)) {
 		gpio_set_level(GPIO_MCDP_READY, 1);
 		pd_log_event(PD_EVENT_VIDEO_CODEC,
 			     PD_LOG_PORT_SIZE(0, sizeof(info)),
diff --git a/driver/mcdp28x0.c b/driver/mcdp28x0.c
index a7d9681c96..d5d37e1bed 100644
--- a/driver/mcdp28x0.c
+++ b/driver/mcdp28x0.c
@@ -139,6 +139,17 @@ static int rx_serial(uint8_t *msg, int cnt)
 	return !(read == cnt);
 }
 
+static int rx_serial_ack(void)
+{
+	if (rx_serial(mcdp_inbuf, 3))
+		return EC_ERROR_UNKNOWN;
+
+	if (mcdp_inbuf[1] != MCDP_CMD_ACK)
+		return EC_ERROR_UNKNOWN;
+
+	return EC_SUCCESS;
+}
+
 void mcdp_enable(void)
 {
 	usart_init(&usart_mcdp);
@@ -151,31 +162,23 @@ void mcdp_disable(void)
 
 int mcdp_get_info(struct mcdp_info  *info)
 {
-	const uint8_t msg[2] = {MCDP_CMD_GETINFO, 0x00}; /* cmd + msg type */
+	const uint8_t msg[2] = {MCDP_CMD_APPSTEST, 0x28};
 
 	if (tx_serial(msg, sizeof(msg)))
 		return EC_ERROR_UNKNOWN;
 
-	if (rx_serial(mcdp_inbuf, MCDP_RSP_LEN(MCDP_LEN_GETINFO)))
+	if (rx_serial_ack())
 		return EC_ERROR_UNKNOWN;
 
+	/* chksum is unreliable ... don't check */
+	rx_serial(mcdp_inbuf, MCDP_RSP_LEN(MCDP_LEN_GETINFO));
+
 	memcpy(info, &mcdp_inbuf[2], MCDP_LEN_GETINFO);
 
 	return EC_SUCCESS;
 }
 
 #ifdef CONFIG_CMD_MCDP
-static int rx_serial_ack(void)
-{
-	if (rx_serial(mcdp_inbuf, 3))
-		return EC_ERROR_UNKNOWN;
-
-	if (mcdp_inbuf[1] != MCDP_CMD_ACK)
-		return EC_ERROR_UNKNOWN;
-
-	return EC_SUCCESS;
-}
-
 static int mcdp_get_dev_id(char *dev, uint8_t dev_id, int dev_cnt)
 {
 	uint8_t msg[2];