anx74xx: Modifed tcpm_get_cc function to fix check for 3.0 A type

When attaching a dump (not PD protocol) TypeC charger, the incorrect
charger type was being selected and therefore it was not enabling 3A
charging. I tracked this issue down to the anx74xx_tcpm_get_cc()
function returning a incorrect value. The expected value was
TYPEC_CC_VOLT_SNK_3_0, but instead it was returning
TYPEC_CC_VOLT_SNK_DEF.

The reason the incorrect cc type was being returned is because the if,
else if, construct didn't work properly for the 3A case where the
upper 2 bits are set. Modified this routine to use a case statement
and consolidated the checks for both cc1 and cc2 into one helper
function.

BRANCH=none
BUG=chrome-os-partner:58738
TEST=manual
Connected zinger and guppy chargers and verified correct cc type was
being returned. In addition tested hoho/dingdong adapters as well as
suzyq. Tested both cable orientations to verify that cc1 and cc2
returned the correct values.

With guppy connected, now see this output on ec console:
C0 HARD RST TX
C0 st5
C0 st36
C0 st37
C0 HARD RST TX
C0 st5
[1921.980074 AC on]
[1922.008140 charge_request(8688mV, 9280mA)]
C0 st6
[1922.910539 Ramp p0 st5 3000mA 3000mA]

Change-Id: I8b31c7ce366f383dfcc2f6e850b76a83340a02a1
Signed-off-by: Scott <scollyer@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/406642
Commit-Ready: Scott Collyer <scollyer@chromium.org>
Tested-by: Scott Collyer <scollyer@chromium.org>
Reviewed-by: Kevin K Wong <kevin.k.wong@intel.com>
Reviewed-by: Shawn N <shawnn@chromium.org>

2 files changed, 50 insertions, 37 deletions

diff --git a/driver/tcpm/anx74xx.c b/driver/tcpm/anx74xx.c
index 5e3681e643..e22e1a49dd 100644
--- a/driver/tcpm/anx74xx.c
+++ b/driver/tcpm/anx74xx.c
@@ -398,37 +398,54 @@ static int anx74xx_read_pd_obj(int port,
 	return rv;
 }
 
+static int anx74xx_check_cc_type(int cc_reg)
+{
+	int cc;
+
+	switch (cc_reg & ANX74XX_REG_CC_STATUS_MASK) {
+	case BIT_VALUE_OF_SRC_CC_RD:
+		cc = TYPEC_CC_VOLT_RD;
+		break;
+
+	case BIT_VALUE_OF_SRC_CC_RA:
+		cc = TYPEC_CC_VOLT_RD;
+		break;
+
+	case BIT_VALUE_OF_SNK_CC_DEFAULT:
+		cc = TYPEC_CC_VOLT_SNK_DEF;
+		break;
+
+	case BIT_VALUE_OF_SNK_CC_1_P_5:
+		cc = TYPEC_CC_VOLT_SNK_1_5;
+		break;
+
+	case BIT_VALUE_OF_SNK_CC_3_P_0:
+		cc = TYPEC_CC_VOLT_SNK_3_0;
+		break;
+
+	default:
+		/* If no bits are set, then nothing is attached */
+		cc = TYPEC_CC_VOLT_OPEN;
+	}
+
+	return cc;
+}
+
 static int anx74xx_tcpm_get_cc(int port, int *cc1, int *cc2)
 {
 	int rv = EC_SUCCESS;
 	int reg = 0;
+
+	/* Read tcpc cc status register */
 	rv |= tcpc_read(port, ANX74XX_REG_CC_STATUS, &reg);
-	/* CC1 */
-	if (reg & BIT_VALUE_OF_SNK_CC1_DEFAULT)
-		*cc1 = TYPEC_CC_VOLT_SNK_DEF;
-	else if (reg & BIT_VALUE_OF_SNK_CC1_1_P_5)
-		*cc1 = TYPEC_CC_VOLT_SNK_1_5;
-	else if (reg & BIT_VALUE_OF_SNK_CC1_3_P_0)
-		*cc1 = TYPEC_CC_VOLT_SNK_3_0;
-	else if (reg & BIT_VALUE_OF_SRC_CC1_RA)
-		*cc1 = TYPEC_CC_VOLT_RA;
-	else if (reg & BIT_VALUE_OF_SRC_CC1_RD)
-		*cc1 = TYPEC_CC_VOLT_RD;
-	else
-		*cc1 = TYPEC_CC_VOLT_OPEN;
-	/* CC2 */
-	if (reg & BIT_VALUE_OF_SNK_CC2_DEFAULT)
-		*cc2 = TYPEC_CC_VOLT_SNK_DEF;
-	else if (reg & BIT_VALUE_OF_SNK_CC2_1_P_5)
-		*cc2 = TYPEC_CC_VOLT_SNK_1_5;
-	else if (reg & BIT_VALUE_OF_SNK_CC2_3_P_0)
-		*cc2 = TYPEC_CC_VOLT_SNK_3_0;
-	else if (reg & BIT_VALUE_OF_SRC_CC2_RA)
-		*cc2 = TYPEC_CC_VOLT_RA;
-	else if (reg & BIT_VALUE_OF_SRC_CC2_RD)
-		*cc2 = TYPEC_CC_VOLT_RD;
-	else
-		*cc2 = TYPEC_CC_VOLT_OPEN;
+	/* Check for cc1 type */
+	*cc1 = anx74xx_check_cc_type(reg);
+	/*
+	 * Check for cc2 type (note cc2 bits are upper 4 of cc status
+	 * register.
+	 */
+	*cc2 = anx74xx_check_cc_type(reg >> 4);
+
 	/* clear HPD status*/
 	if (!(*cc1) && !(*cc2)) {
 		anx74xx_tcpc_clear_hpd_status(port);
@@ -439,6 +456,7 @@ static int anx74xx_tcpm_get_cc(int port, int *cc1, int *cc2)
 
 	return EC_SUCCESS;
 }
+
 static int anx74xx_rp_control(int port, int rp)
 {
 	int reg;
diff --git a/driver/tcpm/anx74xx.h b/driver/tcpm/anx74xx.h
index 6e31dbdf7d..5f0995725d 100644
--- a/driver/tcpm/anx74xx.h
+++ b/driver/tcpm/anx74xx.h
@@ -165,17 +165,12 @@
 #define ANX74XX_REG_STATUS_CC2_VRD_3P0	(1 << 2)
 
 /* defined in the inter-bock Spec: 4.2.10 CC Detect Status */
-
-#define BIT_VALUE_OF_SRC_CC1_RD      0x01
-#define BIT_VALUE_OF_SRC_CC1_RA      0x02
-#define BIT_VALUE_OF_SNK_CC1_DEFAULT 0x04
-#define BIT_VALUE_OF_SNK_CC1_1_P_5   0x08
-#define BIT_VALUE_OF_SNK_CC1_3_P_0   0x0C
-#define BIT_VALUE_OF_SRC_CC2_RD      0x10
-#define BIT_VALUE_OF_SRC_CC2_RA      0x20
-#define BIT_VALUE_OF_SNK_CC2_DEFAULT 0x40
-#define BIT_VALUE_OF_SNK_CC2_1_P_5   0x80
-#define BIT_VALUE_OF_SNK_CC2_3_P_0   0xC0
+#define ANX74XX_REG_CC_STATUS_MASK  0xf
+#define BIT_VALUE_OF_SRC_CC_RD      0x01
+#define BIT_VALUE_OF_SRC_CC_RA      0x02
+#define BIT_VALUE_OF_SNK_CC_DEFAULT 0x04
+#define BIT_VALUE_OF_SNK_CC_1_P_5   0x08
+#define BIT_VALUE_OF_SNK_CC_3_P_0   0x0C
 
 extern const struct tcpm_drv anx74xx_tcpm_drv;
 extern const struct usb_mux_driver anx74xx_tcpm_usb_mux_driver;