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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190508004027.16558-2-angus@akkea.ca> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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) > --- > 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); >