lkml.org 
[lkml]   [2019]   [May]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/1] usb: typec: tcpci: add functions to read the VBUS voltage
Date
Show an error when the VBUS voltage is out of range.

Signed-off-by: Angus Ainslie (Purism) <angus@akkea.ca>
---
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);
+
+ 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);
+ }
+ }
+
return IRQ_HANDLED;
}
EXPORT_SYMBOL_GPL(tcpci_irq);
--
2.17.1
\
 
 \ /
  Last update: 2019-05-08 02:41    [W:0.063 / U:0.656 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site