honeybuns: transform into a real multi-voltage PD source

Switch it to a source-only PD device (as it is)
and add the voltage selection code.

For now, output 12V only for 20V request as the 5V->20V transition is
not monotonic, triggering disconnection detection.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=samus
BUG=chrome-os-partner:37078 chrome-os-partner:41860
TEST=connect to Samus and see it negotiate 5V then 20V,
then manually switch to 12V.

Change-Id: I4fc198245999ff9ce8fec929f305681043d72965
Reviewed-on: https://chromium-review.googlesource.com/259113
Trybot-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Alec Berg <alecaberg@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>

3 files changed, 39 insertions, 15 deletions

diff --git a/board/honeybuns/board.h b/board/honeybuns/board.h
index ec336bfd66..085c057d91 100644
--- a/board/honeybuns/board.h
+++ b/board/honeybuns/board.h
@@ -27,7 +27,7 @@
 #define CONFIG_USB_PD_ALT_MODE
 #undef CONFIG_USB_PD_ALT_MODE_DFP
 #define CONFIG_USB_PD_CUSTOM_VDM
-#define CONFIG_USB_PD_DUAL_ROLE
+#undef CONFIG_USB_PD_DUAL_ROLE
 #define CONFIG_USB_PD_INTERNAL_COMP
 #define CONFIG_USB_PD_PORT_COUNT 1
 #define CONFIG_USB_PD_TCPC
diff --git a/board/honeybuns/gpio.inc b/board/honeybuns/gpio.inc
index 94b136acfb..e18f30ff11 100644
--- a/board/honeybuns/gpio.inc
+++ b/board/honeybuns/gpio.inc
@@ -17,6 +17,7 @@ GPIO(PD_TX_DATA,        PIN(B, 4),  GPIO_OUT_LOW)
 
 /* Power and muxes control */
 GPIO(PP20000_EN,        PIN(A, 8),  GPIO_OUT_LOW)
+GPIO(PP12000_EN,        PIN(A, 14), GPIO_OUT_LOW)
 GPIO(PPVAR_VBUS_EN,     PIN(B, 12), GPIO_OUT_LOW)
 GPIO(SS_MUX_OE_L,       PIN(B, 13), GPIO_OUT_HIGH)
 GPIO(SS_MUX_SEL,        PIN(B, 14), GPIO_OUT_LOW)
@@ -40,7 +41,6 @@ GPIO(MASTER_I2C_SDA,    PIN(B, 7),  GPIO_INPUT)
 
 /* Test points */
 GPIO(TP6,               PIN(A, 13), GPIO_OUT_HIGH /*GPIO_ODR_HIGH*/)
-GPIO(TP7,               PIN(A, 14), GPIO_OUT_LOW /*GPIO_ODR_HIGH*/)
 
 /* Unimplemented signals which we need to emulate for now */
 UNIMPLEMENTED(ENTERING_RW)
diff --git a/board/honeybuns/usb_pd_policy.c b/board/honeybuns/usb_pd_policy.c
index 1debb03ed6..f9d6caf858 100644
--- a/board/honeybuns/usb_pd_policy.c
+++ b/board/honeybuns/usb_pd_policy.c
@@ -19,20 +19,24 @@
 #define CPRINTF(format, args...) cprintf(CC_USBPD, format, ## args)
 #define CPRINTS(format, args...) cprints(CC_USBPD, format, ## args)
 
-#define PDO_FIXED_FLAGS (PDO_FIXED_EXTERNAL | PDO_FIXED_DUAL_ROLE | \
-			 PDO_FIXED_DATA_SWAP)
+#define PDO_FIXED_FLAGS (PDO_FIXED_EXTERNAL | PDO_FIXED_DATA_SWAP)
 
-const uint32_t pd_src_pdo[] = {
-		PDO_FIXED(5000,  3000, PDO_FIXED_FLAGS),
-		PDO_FIXED(12000, 3000, PDO_FIXED_FLAGS),
-		PDO_FIXED(20000, 3000, PDO_FIXED_FLAGS),
+/* Voltage indexes for the PDOs */
+enum volt_idx {
+	PDO_IDX_5V  = 0,
+	PDO_IDX_12V = 1,
+	PDO_IDX_20V = 2,
+
+	PDO_IDX_COUNT
 };
-const int pd_src_pdo_cnt = ARRAY_SIZE(pd_src_pdo);
 
-const uint32_t pd_snk_pdo[] = {
-		PDO_FIXED(5000, 500, PDO_FIXED_FLAGS),
+const uint32_t pd_src_pdo[] = {
+	[PDO_IDX_5V]  = PDO_FIXED(5000,  3000, PDO_FIXED_FLAGS),
+	[PDO_IDX_12V] = PDO_FIXED(12000, 3000, PDO_FIXED_FLAGS),
+	[PDO_IDX_20V] = PDO_FIXED(20000, 3000, PDO_FIXED_FLAGS),
 };
-const int pd_snk_pdo_cnt = ARRAY_SIZE(pd_snk_pdo);
+const int pd_src_pdo_cnt = ARRAY_SIZE(pd_src_pdo);
+BUILD_ASSERT(ARRAY_SIZE(pd_src_pdo) == PDO_IDX_COUNT);
 
 /* Holds valid object position (opos) for entered mode */
 static int alt_mode[PD_AMODE_COUNT];
@@ -78,7 +82,25 @@ int pd_check_requested_voltage(uint32_t rdo)
 
 void pd_transition_voltage(int idx)
 {
-	/* No-operation: we are always 5V */
+	/* PDO index are starting from 1 */
+	switch (idx - 1) {
+	case PDO_IDX_20V:
+#if 0
+		gpio_set_level(GPIO_PPVAR_VBUS_EN, 0);
+		gpio_set_level(GPIO_PP20000_EN, 1);
+		break;
+#endif /* 20V transition is broken, putting 12V instead: fall-through */
+	case PDO_IDX_12V:
+		gpio_set_level(GPIO_PP12000_EN, 1);
+		gpio_set_level(GPIO_PP20000_EN, 0);
+		gpio_set_level(GPIO_PPVAR_VBUS_EN, 1);
+		break;
+	case PDO_IDX_5V:
+	default:
+		gpio_set_level(GPIO_PP12000_EN, 0);
+		gpio_set_level(GPIO_PP20000_EN, 0);
+		gpio_set_level(GPIO_PPVAR_VBUS_EN, 1);
+	}
 }
 
 int pd_set_power_supply_ready(int port)
@@ -92,6 +114,8 @@ void pd_power_supply_reset(int port)
 {
 	/* Kill VBUS */
 	gpio_set_level(GPIO_PPVAR_VBUS_EN, 0);
+	gpio_set_level(GPIO_PP12000_EN, 0);
+	gpio_set_level(GPIO_PP20000_EN, 0);
 }
 
 int pd_snk_is_vbus_provided(int port)
@@ -106,8 +130,8 @@ int pd_board_checks(void)
 
 int pd_check_power_swap(int port)
 {
-	/* Always allow power swap */
-	return 1;
+	/* We are source-only */
+	return 0;
 }
 
 int pd_check_data_swap(int port, int data_role)