linux-kernel - [PATCH 10/14 v1] usb: typec: tcpci: Implement callbacks for FRS

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Message-Id: <20200825042210.300632-11-badhri@google.com>
Date:   Mon, 24 Aug 2020 21:22:06 -0700
From:   Badhri Jagan Sridharan <badhri@...gle.com>
To:     Guenter Roeck <linux@...ck-us.net>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        Badhri Jagan Sridharan <badhri@...gle.com>
Subject: [PATCH 10/14 v1] usb: typec: tcpci: Implement callbacks for FRS

Implement tcpc.enable_frs to enable TCPC to receive
Fast role swap signal.

Additionally set the sink disconnect threshold to 4v
to prevent disconnect during Fast Role swap.

Signed-off-by: Badhri Jagan Sridharan <badhri@...gle.com>
---
 drivers/usb/typec/tcpm/tcpci.c | 17 +++++++++++++++++
 drivers/usb/typec/tcpm/tcpci.h |  8 ++++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index 89d28e3fbee8..13d2e1c2ff20 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -268,6 +268,22 @@ static int tcpci_set_vconn(struct tcpc_dev *tcpc, bool enable)
 				enable ? TCPC_POWER_CTRL_VCONN_ENABLE : 0);
 }
 
+static int tcpci_enable_frs(struct tcpc_dev *dev, bool enable)
+{
+	struct tcpci *tcpci = tcpc_to_tcpci(dev);
+	int ret;
+
+	/* To prevent disconnect during FRS, set disconnect threshold to 3.5V */
+	ret = tcpci_write16(tcpci, TCPC_VBUS_SINK_DISCONNECT_THRESH, enable ? 0 : 0x8c);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_FAST_ROLE_SWAP_EN, enable ?
+				 TCPC_FAST_ROLE_SWAP_EN : 0);
+
+	return ret;
+}
+
 static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
 {
 	struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
@@ -610,6 +626,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
 	tcpci->tcpc.set_roles = tcpci_set_roles;
 	tcpci->tcpc.pd_transmit = tcpci_pd_transmit;
 	tcpci->tcpc.set_bist_data = tcpci_set_bist_data;
+	tcpci->tcpc.enable_frs = tcpci_enable_frs;
 
 	err = tcpci_parse_config(tcpci);
 	if (err < 0)
diff --git a/drivers/usb/typec/tcpm/tcpci.h b/drivers/usb/typec/tcpm/tcpci.h
index 82f021a82456..5ef07a56d67a 100644
--- a/drivers/usb/typec/tcpm/tcpci.h
+++ b/drivers/usb/typec/tcpm/tcpci.h
@@ -16,6 +16,7 @@
 #define TCPC_PD_INT_REV			0xa
 
 #define TCPC_ALERT			0x10
+#define TCPC_ALERT_EXTND		BIT(14)
 #define TCPC_ALERT_EXTENDED_STATUS	BIT(13)
 #define TCPC_ALERT_VBUS_DISCNCT		BIT(11)
 #define TCPC_ALERT_RX_BUF_OVF		BIT(10)
@@ -37,6 +38,9 @@
 #define TCPC_EXTENDED_STATUS_MASK		0x16
 #define TCPC_EXTENDED_STATUS_MASK_VSAFE0V	BIT(0)
 
+#define TCPC_ALERT_EXTENDED_MASK	0x17
+#define TCPC_SINK_FAST_ROLE_SWAP	BIT(0)
+
 #define TCPC_CONFIG_STD_OUTPUT		0x18
 
 #define TCPC_TCPC_CTRL			0x19
@@ -63,6 +67,7 @@
 
 #define TCPC_POWER_CTRL			0x1c
 #define TCPC_POWER_CTRL_VCONN_ENABLE	BIT(0)
+#define TCPC_FAST_ROLE_SWAP_EN		BIT(7)
 
 #define TCPC_CC_STATUS			0x1d
 #define TCPC_CC_STATUS_TOGGLING		BIT(5)
@@ -74,11 +79,14 @@
 
 #define TCPC_POWER_STATUS		0x1e
 #define TCPC_POWER_STATUS_UNINIT	BIT(6)
+#define TCPC_POWER_STATUS_SOURCING_VBUS	BIT(4)
 #define TCPC_POWER_STATUS_VBUS_DET	BIT(3)
 #define TCPC_POWER_STATUS_VBUS_PRES	BIT(2)
 
 #define TCPC_FAULT_STATUS		0x1f
 
+#define TCPC_ALERT_EXTENDED		0x21
+
 #define TCPC_COMMAND			0x23
 #define TCPC_CMD_WAKE_I2C		0x11
 #define TCPC_CMD_DISABLE_VBUS_DETECT	0x22
-- 
2.28.0.297.g1956fa8f8d-goog