[PATCH v6 11/14] usb: typec: tcpci_maxim: Add support for Sink FRS

Badhri Jagan Sridharan
2020-09-01T03:00:01Z

Upon receiving ALERT_EXTENDED.TCPC_SINK_FAST_ROLE_SWAP signal
tcpm to start Sink fast role swap signal.

Inform when TCPM is sourcing vbus.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
Changes since v1:
- Changing patch version to v6 to fix version number confusion.
---
drivers/usb/typec/tcpm/tcpci_maxim.c | 50 +++++++++++++++++++++++++---
1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim.c
index b61f290a8f96..6ba808ad901a 100644
--- a/drivers/usb/typec/tcpm/tcpci_maxim.c
+++ b/drivers/usb/typec/tcpm/tcpci_maxim.c
@@ -106,13 +106,22 @@ static void max_tcpci_init_regs(struct max_tcpci_chip *chip)
return;
}

+ ret = max_tcpci_write8(chip, TCPC_ALERT_EXTENDED, 0xff);
+ if (ret < 0) {
+ dev_err(chip->dev, "Unable to clear TCPC_ALERT_EXTENDED ret:%d\n", ret);
+ return;
+ }
+
alert_mask = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_TX_FAILED |
TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_RX_STATUS | TCPC_ALERT_CC_STATUS |
- TCPC_ALERT_VBUS_DISCNCT | TCPC_ALERT_RX_BUF_OVF | TCPC_ALERT_POWER_STATUS;
+ TCPC_ALERT_VBUS_DISCNCT | TCPC_ALERT_RX_BUF_OVF | TCPC_ALERT_POWER_STATUS |
+ /* Enable Extended alert for detecting Fast Role Swap Signal */
+ TCPC_ALERT_EXTND;

ret = max_tcpci_write16(chip, TCPC_ALERT_MASK, alert_mask);
if (ret < 0) {
- dev_err(chip->dev, "Error writing to TCPC_ALERT_MASK ret:%d\n", ret);
+ dev_err(chip->dev,
+ "Error enabling TCPC_ALERT: TCPC_ALERT_MASK write failed ret:%d\n", ret);
return;
}

@@ -122,6 +131,10 @@ static void max_tcpci_init_regs(struct max_tcpci_chip *chip)
dev_err(chip->dev, "Error writing to TCPC_POWER_CTRL ret:%d\n", ret);
return;
}
+
+ ret = max_tcpci_write8(chip, TCPC_ALERT_EXTENDED_MASK, TCPC_SINK_FAST_ROLE_SWAP);
+ if (ret < 0)
+ return;
}

static void process_rx(struct max_tcpci_chip *chip, u16 status)
@@ -225,10 +238,23 @@ static void process_power_status(struct max_tcpci_chip *chip)
if (ret < 0)
return;

- if (pwr_status == 0xff)
+ if (pwr_status == 0xff) {
max_tcpci_init_regs(chip);
- else
+ } else if (pwr_status & TCPC_POWER_STATUS_SOURCING_VBUS) {
+ tcpm_sourcing_vbus(chip->port);
+ /*
+ * Alawys re-enable boost here.
+ * In normal case, when say an headset is attached, TCPM would
+ * have instructed to TCPC to enable boost, so the call is a
+ * no-op.
+ * But for Fast Role Swap case, Boost turns on autonomously without
+ * AP intervention, but, needs AP to enable source mode explicitly
+ * for AP to regain control.
+ */
+ max_tcpci_set_vbus(chip->tcpci, &chip->data, true, false);
+ } else {
tcpm_vbus_change(chip->port);
+ }
}

static void process_tx(struct max_tcpci_chip *chip, u16 status)
@@ -249,6 +275,7 @@ static irqreturn_t _max_tcpci_irq(struct max_tcpci_chip *chip, u16 status)
{
u16 mask;
int ret;
+ u8 reg_status;

/*
* Clear alert status for everything except RX_STATUS, which shouldn't
@@ -274,6 +301,21 @@ static irqreturn_t _max_tcpci_irq(struct max_tcpci_chip *chip, u16 status)
}
}

+ if (status & TCPC_ALERT_EXTND) {
+ ret = max_tcpci_read8(chip, TCPC_ALERT_EXTENDED, &reg_status);
+ if (ret < 0)
+ return ret;
+
+ ret = max_tcpci_write8(chip, TCPC_ALERT_EXTENDED, reg_status);
+ if (ret < 0)
+ return ret;
+
+ if (reg_status & TCPC_SINK_FAST_ROLE_SWAP) {
+ dev_info(chip->dev, "FRS Signal");
+ tcpm_sink_frs(chip->port);
+ }
+ }
+
if (status & TCPC_ALERT_RX_STATUS)
process_rx(chip, status);

--
2.28.0.402.g5ffc5be6b7-goog