On 5/7/19 5:40 PM, Angus Ainslie (Purism) wrote:
Show an error when the VBUS voltage is out of range.
Signed-off-by: Angus Ainslie (Purism) <angus@xxxxxxxx>
---
drivers/usb/typec/tcpm/tcpci.c | 35 ++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index a5746657b190..223941e11ef3 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -261,6 +261,26 @@ static int tcpci_set_pd_rx(struct tcpc_dev *tcpc, bool enable)
return 0;
}
+static int tcpci_get_vbus_voltage(struct tcpc_dev *tcpc)
+{
+ struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
+ u16 vbus_reg;
+ unsigned int vbus_voltage;
+ int ret, scale;
+
+ ret = tcpci_read16(tcpci, TCPC_VBUS_VOLTAGE, &vbus_reg);
+ if (ret < 0)
+ return ret;
+
+ vbus_voltage = vbus_reg & 0x3f;
+
+ scale = (vbus_reg >> 10) & 3;
+ if (scale == 3)
+ return -EIO;
+
+ return (vbus_voltage << scale) * 25;
+}
+
static int tcpci_get_vbus(struct tcpc_dev *tcpc)
{
struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
@@ -401,6 +421,7 @@ static int tcpci_init(struct tcpc_dev *tcpc)
irqreturn_t tcpci_irq(struct tcpci *tcpci)
{
u16 status;
+ int ret;
tcpci_read16(tcpci, TCPC_ALERT, &status);
@@ -474,6 +495,20 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci)
tcpci_write16(tcpci, TCPC_FAULT_STATUS, fault_status);
}
+ if (status & (TCPC_ALERT_V_ALARM_LO | TCPC_ALERT_V_ALARM_HI)) {
+ ret = tcpci_get_vbus_voltage(&tcpci->tcpc);
+
Extra empty line.
+ if (ret >= 0) {
+ if (status & TCPC_ALERT_V_ALARM_LO)
+ dev_err(tcpci->dev, "Low VBUS voltage %d mV\n",
+ ret);
+
+ if (status & TCPC_ALERT_V_ALARM_HI)
+ dev_err(tcpci->dev, "High VBUS voltage %d mV\n",
+ ret);
+ }
This doesn't report anything if reading the VBUS voltage
returns an error.
Also, per TCPCI specification, you probably want to check
POWER_CONTROL.VBUS_VOLTAGE Monitor to see if it is enabled
in the first place.
On a higher level, the driver doesn't currently set limits for low
and high voltage alarms, and it doesn't enable those alarms. As such,
I wonder if/how you can get those alerts. Can you clarify ?
Thanks,
Guenter
+ }
+
return IRQ_HANDLED;
}
EXPORT_SYMBOL_GPL(tcpci_irq);
