sn5s330: add low power mode

Add a low power mode method for PPCs behind a new config.
Implement the low power method for SN5S330 based off of TI AE
recommendation.

BRANCH=none
BUG=b:111520593,b:111006203
TEST=CL stack produce lower power during bip hibernate

Change-Id: Icd22f88a8f65c2cd5ab1c95b0750b1eb61e91923
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1166183
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Furquan Shaikh <furquan@chromium.org>

4 files changed, 106 insertions, 22 deletions

diff --git a/common/usbc_ppc.c b/common/usbc_ppc.c
index 7011309cf1..0961ba6e83 100644
--- a/common/usbc_ppc.c
+++ b/common/usbc_ppc.c
@@ -86,6 +86,19 @@ int ppc_vbus_sink_enable(int port, int enable)
 	return ppc_chips[port].drv->vbus_sink_enable(port, enable);
 }
 
+int ppc_enter_low_power_mode(int port)
+{
+	const struct ppc_config_t *const ppc = &ppc_chips[port];
+
+	if ((port < 0) || (port >= ppc_cnt))
+		return EC_ERROR_INVAL;
+
+	if (ppc->drv->enter_low_power_mode)
+		return ppc->drv->enter_low_power_mode(port);
+	else
+		return EC_ERROR_UNIMPLEMENTED;
+}
+
 int ppc_vbus_source_enable(int port, int enable)
 {
 	if ((port < 0) || (port >= ppc_cnt))
diff --git a/driver/ppc/sn5s330.c b/driver/ppc/sn5s330.c
index 9855ab1d89..904a968a03 100644
--- a/driver/ppc/sn5s330.c
+++ b/driver/ppc/sn5s330.c
@@ -514,6 +514,54 @@ static int sn5s330_discharge_vbus(int port, int enable)
 	return EC_SUCCESS;
 }
 
+static int sn5s330_enter_low_power_mode(int port)
+{
+	int rv;
+
+	/* Turn off both SRC and SNK FETs */
+	rv = clr_flags(port, SN5S330_FUNC_SET3,
+		       SN5S330_PP1_EN | SN5S330_PP2_EN);
+
+	if (rv) {
+		CPRINTS("ppc p%d: Could not disable both FETS (%d)", port, rv);
+		return rv;
+	}
+
+	/* Turn off Vconn power */
+	rv = clr_flags(port, SN5S330_FUNC_SET4, SN5S330_VCONN_EN);
+
+	if (rv) {
+		CPRINTS("ppc p%d: Could not disable Vconn (%d)", port, rv);
+		return rv;
+	}
+
+	/* Turn off SBU path */
+	rv = clr_flags(port, SN5S330_FUNC_SET2, SN5S330_SBU_EN);
+
+	if (rv) {
+		CPRINTS("ppc p%d: Could not disable SBU path (%d)", port, rv);
+		return rv;
+	}
+
+	/*
+	 * Turn off the Over Voltage Protection circuits. Needs to happen after
+	 * FETs are disabled, otherwise OVP can automatically turned back on.
+	 * Since FETs are off, any over voltage does not make it to the board
+	 * side of the PPC.
+	 */
+	rv = clr_flags(port, SN5S330_FUNC_SET9,
+		       SN5S330_FORCE_OVP_EN_SBU | SN5S330_FORCE_ON_VBUS_OVP |
+			       SN5S330_FORCE_ON_VBUS_UVP);
+
+	if (rv) {
+		CPRINTS("ppc p%d: Could not disable OVP circuit (%d)", port,
+			rv);
+		return rv;
+	}
+
+	return EC_SUCCESS;
+}
+
 #ifdef CONFIG_USBC_PPC_VCONN
 static int sn5s330_set_vconn(int port, int enable)
 {
@@ -600,17 +648,18 @@ const struct ppc_drv sn5s330_drv = {
 	.is_sourcing_vbus = &sn5s330_is_sourcing_vbus,
 	.vbus_sink_enable = &sn5s330_vbus_sink_enable,
 	.vbus_source_enable = &sn5s330_vbus_source_enable,
+	.set_vbus_source_current_limit = &sn5s330_set_vbus_source_current_limit,
+	.discharge_vbus = &sn5s330_discharge_vbus,
+	.enter_low_power_mode = &sn5s330_enter_low_power_mode,
 #ifdef CONFIG_CMD_PPC_DUMP
 	.reg_dump = &sn5s330_dump,
-#endif /* defined(CONFIG_CMD_PPC_DUMP) */
+#endif
 #ifdef CONFIG_USB_PD_VBUS_DETECT_PPC
 	.is_vbus_present = &sn5s330_is_vbus_present,
-#endif /* defined(CONFIG_USB_PD_VBUS_DETECT_PPC) */
+#endif
 #ifdef CONFIG_USBC_PPC_POLARITY
 	.set_polarity = &sn5s330_set_polarity,
 #endif
-	.set_vbus_source_current_limit = &sn5s330_set_vbus_source_current_limit,
-	.discharge_vbus = &sn5s330_discharge_vbus,
 #ifdef CONFIG_USBC_PPC_VCONN
 	.set_vconn = &sn5s330_set_vconn,
 #endif
diff --git a/driver/ppc/sn5s330.h b/driver/ppc/sn5s330.h
index 2b17a1d46a..fcb41204ef 100644
--- a/driver/ppc/sn5s330.h
+++ b/driver/ppc/sn5s330.h
@@ -86,34 +86,37 @@ enum sn5s330_pp_idx {
 #define SN5S330_ILIM_3_30  12
 
 /* FUNC_SET_2 */
-#define SN5S330_SBU_EN (1 << 4)
+#define SN5S330_SBU_EN			(1 << 4)
 
 /* FUNC_SET_3 */
-#define SN5S330_PP1_EN (1 << 0)
-#define SN5S330_PP2_EN (1 << 1)
-#define SN5S330_VBUS_DISCH_EN (1 << 2)
-#define SN5S330_SET_RCP_MODE_PP1 (1 << 5)
-#define SN5S330_SET_RCP_MODE_PP2 (1 << 6)
+#define SN5S330_PP1_EN			(1 << 0)
+#define SN5S330_PP2_EN			(1 << 1)
+#define SN5S330_VBUS_DISCH_EN		(1 << 2)
+#define SN5S330_SET_RCP_MODE_PP1	(1 << 5)
+#define SN5S330_SET_RCP_MODE_PP2	(1 << 6)
 
 /* FUNC_SET_4 */
-#define SN5S330_VCONN_EN (1 << 0)
-#define SN5S330_CC_POLARITY (1 << 1)
-#define SN5S330_CC_EN (1 << 4)
-#define SN5S330_VCONN_ILIM_SEL (1 << 5)
+#define SN5S330_VCONN_EN		(1 << 0)
+#define SN5S330_CC_POLARITY		(1 << 1)
+#define SN5S330_CC_EN			(1 << 4)
+#define SN5S330_VCONN_ILIM_SEL		(1 << 5)
 
 /* FUNC_SET_9 */
-#define SN5S330_PP2_CONFIG (1 << 2)
-#define SN5S330_OVP_EN_CC (1 << 4)
-#define SN5S330_CONFIG_UVP (1 << 5)
+#define SN5S330_FORCE_OVP_EN_SBU	(1 << 1)
+#define SN5S330_PP2_CONFIG		(1 << 2)
+#define SN5S330_OVP_EN_CC		(1 << 4)
+#define SN5S330_CONFIG_UVP		(1 << 5)
+#define SN5S330_FORCE_ON_VBUS_OVP	(1 << 6)
+#define SN5S330_FORCE_ON_VBUS_UVP	(1 << 7)
 
 /* INT_STATUS_REG3 */
-#define SN5S330_VBUS_GOOD (1 << 0)
+#define SN5S330_VBUS_GOOD		(1 << 0)
 
 /* INT_STATUS_REG4 */
-#define SN5S330_DIG_RES (1 << 0)
-#define SN5S330_DB_BOOT (1 << 1)
-#define SN5S330_VSAFE0V_STAT (1 << 2)
-#define SN5S330_VSAFE0V_MASK (1 << 3)
+#define SN5S330_DIG_RES			(1 << 0)
+#define SN5S330_DB_BOOT			(1 << 1)
+#define SN5S330_VSAFE0V_STAT		(1 << 2)
+#define SN5S330_VSAFE0V_MASK		(1 << 3)
 
 /*
  * INT_MASK_RISE/FALL_EDGE_1
diff --git a/include/usbc_ppc.h b/include/usbc_ppc.h
index d65fa79f0e..a93f7e7109 100644
--- a/include/usbc_ppc.h
+++ b/include/usbc_ppc.h
@@ -106,6 +106,15 @@ struct ppc_drv {
 	 */
 	int (*is_vbus_present)(int port);
 #endif /* defined(CONFIG_USB_PD_VBUS_DETECT_PPC) */
+
+	/**
+	 * Optional method to put the PPC into its lowest power state. In this
+	 * state it should still fire interrupts if Vbus changes etc.
+	 *
+	 * @param port: The Type-C port number.
+	 * @return EC_SUCCESS on success, error otherwise.
+	 */
+	int (*enter_low_power_mode)(int port);
 };
 
 struct ppc_config_t {
@@ -203,4 +212,14 @@ int ppc_vbus_source_enable(int port, int enable);
  */
 void board_overcurrent_event(int port);
 
+/**
+ * Put the PPC into its lowest power state. In this state it should still fire
+ * interrupts if Vbus changes etc. This is called by board-specific code when
+ * appropriate.
+ *
+ * @param port: The Type-C port number.
+ * @return EC_SUCCESS on success, error otherwise.
+ */
+int ppc_enter_low_power_mode(int port);
+
 #endif /* !defined(__CROS_EC_USBC_PPC_H) */