sn5s330: Add support for SBU FET control.

The SN5S330 has FETs for the SBU lines which need to be controlled by
the TCPM.  This commit adds a function to control the SBU FETs and
enables them when configuring the USB mux.

This commit also fixes a bug with the external VBUS current limit
setting by setting it appropriately to a min of ~3A.

BUG=b:114340064
BRANCH=firmware-nocturne-10984.B
TEST=Flash nocturne; plug in hoho; verify that external display is
shown. Bounce thru S5, verify that external display still works.
TEST=Repeat above with superspeed hub instead.

Change-Id: I931f7a47d4eb28e8d9e3cb188601ce0889a44f8d
Signed-off-by: Aseda Aboagye <aaboagye@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1244382
Commit-Queue: Aseda Aboagye <aaboagye@chromium.org>
Tested-by: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1530125
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Edward Hill <ecgh@chromium.org>
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

5 files changed, 59 insertions, 1 deletions

diff --git a/common/usbc_ppc.c b/common/usbc_ppc.c
index 9ec33a3ec1..54da1f22b4 100644
--- a/common/usbc_ppc.c
+++ b/common/usbc_ppc.c
@@ -140,6 +140,16 @@ int ppc_is_port_latched_off(int port)
 	return oc_event_cnt_tbl[port] >= PPC_OC_CNT_THRESH;
 }
 
+#ifdef CONFIG_USBC_PPC_SBU
+int ppc_set_sbu(int port, int enable)
+{
+	if ((port < 0) || (port >= ppc_cnt))
+		return EC_ERROR_INVAL;
+
+	return ppc_chips[port].drv->set_sbu(port, enable);
+}
+#endif /* defined(CONFIG_USBC_PPC_SBU) */
+
 #ifdef CONFIG_USBC_PPC_VCONN
 int ppc_set_vconn(int port, int enable)
 {
diff --git a/driver/ppc/sn5s330.c b/driver/ppc/sn5s330.c
index 6b48c8650b..c73182ca81 100644
--- a/driver/ppc/sn5s330.c
+++ b/driver/ppc/sn5s330.c
@@ -246,7 +246,7 @@ static int sn5s330_init(int port)
 	}
 
 	/* Enable SBU Fets and set PP2 current limit to ~3A. */
-	regval = SN5S330_SBU_EN | 0xf;
+	regval = SN5S330_SBU_EN | 0x8;
 	status = i2c_write8(i2c_port, i2c_addr, SN5S330_FUNC_SET2, regval);
 	if (status) {
 		CPRINTS("ppc p%d: Failed to set FUNC_SET2!", port);
@@ -667,6 +667,20 @@ static void sn5s330_handle_interrupt(int port)
 	}
 }
 
+#ifdef CONFIG_USBC_PPC_SBU
+static int sn5s330_set_sbu(int port, int enable)
+{
+	int rv;
+
+	if (enable)
+		rv = set_flags(port, SN5S330_FUNC_SET2, SN5S330_SBU_EN);
+	else
+		rv = clr_flags(port, SN5S330_FUNC_SET2, SN5S330_SBU_EN);
+
+	return rv;
+}
+#endif /* CONFIG_USBC_PPC_SBU */
+
 static void sn5s330_irq_deferred(void)
 {
 	int i;
@@ -701,6 +715,9 @@ const struct ppc_drv sn5s330_drv = {
 #ifdef CONFIG_USBC_PPC_POLARITY
 	.set_polarity = &sn5s330_set_polarity,
 #endif
+#ifdef CONFIG_USBC_PPC_SBU
+	.set_sbu = &sn5s330_set_sbu,
+#endif /* defined(CONFIG_USBC_PPC_SBU) */
 #ifdef CONFIG_USBC_PPC_VCONN
 	.set_vconn = &sn5s330_set_vconn,
 #endif
diff --git a/driver/usb_mux.c b/driver/usb_mux.c
index 5ef11d7ac1..2b94dede60 100644
--- a/driver/usb_mux.c
+++ b/driver/usb_mux.c
@@ -9,6 +9,7 @@
 #include "console.h"
 #include "host_command.h"
 #include "usb_mux.h"
+#include "usbc_ppc.h"
 #include "util.h"
 
 #define CPRINTS(format, args...) cprints(CC_USBCHARGE, format, ## args)
@@ -97,6 +98,14 @@ void usb_mux_set(int port, enum typec_mux mux_mode,
 	usb_charger_set_switches(port, usb_mode);
 #endif
 
+#ifdef CONFIG_USBC_PPC_SBU
+	/* Make sure to disable/enable the SBU FETs if needed. */
+	if (mux_mode == TYPEC_MUX_NONE)
+		ppc_set_sbu(port, 0);
+	else
+		ppc_set_sbu(port, 1);
+#endif /* CONFIG_USBC_PPC_SBU */
+
 	/*
 	 * Don't wake device up just to put it back to sleep. Low power mode
 	 * flag is only set if the mux set() operation succeeded previously for
diff --git a/include/config.h b/include/config.h
index b53c48cfc1..5607fecde2 100644
--- a/include/config.h
+++ b/include/config.h
@@ -3463,6 +3463,9 @@
 #undef CONFIG_USBC_PPC_SN5S330
 #undef CONFIG_USBC_PPC_SYV682X
 
+/* PPC is capable of gating the SBU lines. */
+#undef CONFIG_USBC_PPC_SBU
+
 /* PPC is capable of providing VCONN */
 #undef CONFIG_USBC_PPC_VCONN
 
@@ -4028,6 +4031,7 @@
 /* The TI SN5S330 supports VCONN and needs to be informed of CC polarity */
 #if defined(CONFIG_USBC_PPC_SN5S330)
 #define CONFIG_USBC_PPC_POLARITY
+#define CONFIG_USBC_PPC_SBU
 #define CONFIG_USBC_PPC_VCONN
 #endif
 
diff --git a/include/usbc_ppc.h b/include/usbc_ppc.h
index a502ebe91e..fbd4385afc 100644
--- a/include/usbc_ppc.h
+++ b/include/usbc_ppc.h
@@ -89,6 +89,16 @@ struct ppc_drv {
 	 */
 	int (*discharge_vbus)(int port, int enable);
 
+#ifdef CONFIG_USBC_PPC_SBU
+	/**
+	 * Turn on/off the SBU FETs.
+	 *
+	 * @param port: The Type-C port number.
+	 * @param enable: 1: enable SBU FETs 0: disable SBU FETs.
+	 */
+	int (*set_sbu)(int port, int enable);
+#endif /* CONFIG_USBC_PPC_SBU */
+
 #ifdef CONFIG_USBC_PPC_VCONN
 	/**
 	 * Turn on/off the VCONN FET.
@@ -225,6 +235,14 @@ int ppc_set_polarity(int port, int polarity);
 int ppc_set_vbus_source_current_limit(int port, enum tcpc_rp_value rp);
 
 /**
+ * Turn on/off the SBU FETs.
+ *
+ * @param port: The Type-C port number.
+ * @param enable: 1: enable SBU FETs 0: disable SBU FETs.
+ */
+int ppc_set_sbu(int port, int enable);
+
+/**
  * Turn on/off the VCONN FET.
  *
  * @param port: The Type-C port number.