[PATCH v4 7/7] usb: typec: tcpci_rt1711h: Fix CC PHY noise filter of voltage level

[Gene Chen]

From: Gene Chen <gene_chen@xxxxxxxxxxx>

Fix CC PHY noise filter of voltage level according to
current cc voltage level

Signed-off-by: Gene Chen <gene_chen@xxxxxxxxxxx>
Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
 drivers/usb/typec/tcpm/tcpci_rt1711h.c | 58 +++++++++++++++++++++++++++++++++-
 1 file changed, 57 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpci_rt1711h.c b/drivers/usb/typec/tcpm/tcpci_rt1711h.c
index ff7deae..5dc34f9 100644
--- a/drivers/usb/typec/tcpm/tcpci_rt1711h.c
+++ b/drivers/usb/typec/tcpm/tcpci_rt1711h.c
@@ -24,8 +24,11 @@
 #define RT1711H_PHYCTRL1	0x80
 #define RT1711H_PHYCTRL2	0x81
 
-#define RT1711H_RTCTRL8		0x9B
+#define RT1711H_RTCTRL4		0x93
+/* rx threshold of rd/rp: 1b0 for level 0.4V/0.7V, 1b1 for 0.35V/0.75V */
+#define RT1711H_BMCIO_RXDZSEL	BIT(0)
 
+#define RT1711H_RTCTRL8		0x9B
 /* Autoidle timeout = (tout * 2 + 1) * 6.4ms */
 #define RT1711H_RTCTRL8_SET(ck300, ship_off, auto_idle, tout) \
 			    (((ck300) << 7) | ((ship_off) << 5) | \
@@ -44,6 +47,10 @@
 #define RT1711H_RTCTRL15	0xA2
 #define RT1711H_RTCTRL16	0xA3
 
+#define RT1711H_RTCTRL18	0xAF
+/* 1b0 as fixed rx threshold of rd/rp 0.55V, 1b1 depends on RTCRTL4[0] */
+#define BMCIO_RXDZEN	BIT(0)
+
 struct rt1711h_chip {
 	struct tcpci_data data;
 	struct tcpci *tcpci;
@@ -164,6 +171,53 @@ static int rt1711h_set_vconn(struct tcpci *tcpci, struct tcpci_data *tdata,
 				  RT1711H_AUTOIDLEEN, enable ? 0 : RT1711H_AUTOIDLEEN);
 }
 
+/*
+ * Selects the CC PHY noise filter voltage level according to the remote current
+ * CC voltage level.
+ *
+ * @status: The port's current cc status read from IC
+ * Return 0 if writes succeed; failure code otherwise
+ */
+static inline int rt1711h_init_cc_params(struct rt1711h_chip *chip, u8 status)
+{
+	int ret, cc1, cc2;
+	u8 role = 0;
+	u32 rxdz_en, rxdz_sel;
+
+	ret = rt1711h_read8(chip, TCPC_ROLE_CTRL, &role);
+	if (ret < 0)
+		return ret;
+
+	cc1 = tcpci_to_typec_cc((status >> TCPC_CC_STATUS_CC1_SHIFT) &
+				TCPC_CC_STATUS_CC1_MASK,
+				status & TCPC_CC_STATUS_TERM ||
+				tcpc_presenting_rd(role, CC1));
+	cc2 = tcpci_to_typec_cc((status >> TCPC_CC_STATUS_CC2_SHIFT) &
+				TCPC_CC_STATUS_CC2_MASK,
+				status & TCPC_CC_STATUS_TERM ||
+				tcpc_presenting_rd(role, CC2));
+
+	if ((cc1 >= TYPEC_CC_RP_1_5 && cc2 < TYPEC_CC_RP_DEF) ||
+	    (cc2 >= TYPEC_CC_RP_1_5 && cc1 < TYPEC_CC_RP_DEF)) {
+		rxdz_en = BMCIO_RXDZEN;
+		if (chip->did == RT1715_DID)
+			rxdz_sel = RT1711H_BMCIO_RXDZSEL;
+		else
+			rxdz_sel = 0;
+	} else {
+		rxdz_en = 0;
+		rxdz_sel = RT1711H_BMCIO_RXDZSEL;
+	}
+
+	ret = regmap_update_bits(chip->data.regmap, RT1711H_RTCTRL18,
+				 BMCIO_RXDZEN, rxdz_en);
+	if (ret < 0)
+		return ret;
+
+	return regmap_update_bits(chip->data.regmap, RT1711H_RTCTRL4,
+				  RT1711H_BMCIO_RXDZSEL, rxdz_sel);
+}
+
 static int rt1711h_start_drp_toggling(struct tcpci *tcpci,
 				      struct tcpci_data *tdata,
 				      enum typec_cc_status cc)
@@ -224,6 +278,8 @@ static irqreturn_t rt1711h_irq(int irq, void *dev_id)
 		/* Clear cc change event triggered by starting toggling */
 		if (status & TCPC_CC_STATUS_TOGGLING)
 			rt1711h_write8(chip, TCPC_ALERT, TCPC_ALERT_CC_STATUS);
+		else
+			rt1711h_init_cc_params(chip, status);
 	}
 
 out:
-- 
2.7.4