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Message-Id: <20200921195555.1050731-10-badhri@google.com>
Date: Mon, 21 Sep 2020 12:55:54 -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>,
Rob Herring <robh+dt@...nel.org>,
Lee Jones <lee.jones@...aro.org>,
Mark Brown <broonie@...nel.org>,
Maxime Ripard <mripard@...nel.org>,
Alexandre Belloni <alexandre.belloni@...tlin.com>,
Thierry Reding <treding@...dia.com>,
Prashant Malani <pmalani@...omium.org>,
Badhri Jagan Sridharan <badhri@...gle.com>
Cc: devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-usb@...r.kernel.org
Subject: [PATCH v8 10/11] usb: typec: tcpci: Implement Auto discharge
disconnect callbacks
Implement callbacks for enabling/disabling
POWER_CONTROL.AutoDischargeDisconnect.
TCPCI spec allows TCPC hardware to autonomously discharge the vbus
capacitance upon disconnect. The expectation is that the TCPM enables
AutoDischargeDisconnect while entering SNK/SRC_ATTACHED states. Hardware
then automously discharges vbus when the vbus falls below a certain
threshold i.e. VBUS_SINK_DISCONNECT_THRESHOLD.
Apart from enabling the vbus discharge circuit, AutoDischargeDisconnect
is also used a flag to move TCPCI based TCPC implementations into
Attached.Snk/Attached.Src state as mentioned in
Figure 4-15. TCPC State Diagram before a Connection of the
USB Type-C Port Controller Interface Specification.
In such TCPC implementations, setting AutoDischargeDisconnect would
prevent TCPC into entering "Connection_Invalid" state as well.
Signed-off-by: Badhri Jagan Sridharan <badhri@...gle.com>
---
Changes since v1:
- Changing patch version to v6 to fix version number confusion.
Changes since v6:
- Rebase on usb-next.
Changes since v7:
Heikki's suggestion:
- Moved the actual write to TCPC_VBUS_SINK_DISCONNECT_THRESH
as it's common to all chip drivers.
- Renaming the tcpci_data callback as
get_auto_vbus_discharge_threshold
---
drivers/usb/typec/tcpm/tcpci.c | 48 ++++++++++++++++++++++++++++++++++
drivers/usb/typec/tcpm/tcpci.h | 22 ++++++++++++++--
2 files changed, 68 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index f9f0af64da5f..dca21cd5873e 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -268,6 +268,48 @@ static int tcpci_set_vconn(struct tcpc_dev *tcpc, bool enable)
enable ? TCPC_POWER_CTRL_VCONN_ENABLE : 0);
}
+static int tcpci_enable_auto_vbus_discharge(struct tcpc_dev *dev, bool enable)
+{
+ struct tcpci *tcpci = tcpc_to_tcpci(dev);
+ int ret;
+
+ ret = regmap_update_bits(tcpci->regmap, TCPC_POWER_CTRL, TCPC_POWER_CTRL_AUTO_DISCHARGE,
+ enable ? TCPC_POWER_CTRL_AUTO_DISCHARGE : 0);
+ return ret;
+}
+
+static int tcpci_set_auto_vbus_discharge_threshold(struct tcpc_dev *dev, enum typec_role port_role,
+ enum typec_pwr_opmode mode, bool pps_active,
+ u32 requested_vbus_voltage_mv)
+{
+ struct tcpci *tcpci = tcpc_to_tcpci(dev);
+ u32 (*get_auto_vbus_threshold)(struct tcpci *tcpci, struct tcpci_data *data,
+ enum typec_role port_role, enum typec_pwr_opmode mode,
+ bool pps_active, u32 requested_vbus_voltage_mv);
+
+ get_auto_vbus_threshold = tcpci->data->get_auto_vbus_discharge_threshold;
+ if (get_auto_vbus_threshold) {
+ u32 threshold;
+ u16 val;
+
+ /*
+ * Indicates that vbus is going to go away due PR_SWAP, hard reset etc.
+ * Do not discharge vbus here.
+ */
+ threshold = requested_vbus_voltage_mv ?
+ get_auto_vbus_threshold(tcpci, tcpci->data, port_role, mode, pps_active,
+ requested_vbus_voltage_mv) : 0;
+
+ val = threshold / TCPC_VBUS_SINK_DISCONNECT_THRESH_LSB_MV;
+ if (val > TCPC_VBUS_SINK_DISCONNECT_THRESH_MAX)
+ return -EINVAL;
+
+ return tcpci_write16(tcpci, TCPC_VBUS_SINK_DISCONNECT_THRESH, val);
+ }
+
+ return 0;
+}
+
static int tcpci_enable_frs(struct tcpc_dev *dev, bool enable)
{
struct tcpci *tcpci = tcpc_to_tcpci(dev);
@@ -629,6 +671,12 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
tcpci->tcpc.set_bist_data = tcpci_set_bist_data;
tcpci->tcpc.enable_frs = tcpci_enable_frs;
+ if (tcpci->data->auto_discharge_disconnect) {
+ tcpci->tcpc.enable_auto_vbus_discharge = tcpci_enable_auto_vbus_discharge;
+ tcpci->tcpc.set_auto_vbus_discharge_threshold =
+ tcpci_set_auto_vbus_discharge_threshold;
+ }
+
err = tcpci_parse_config(tcpci);
if (err < 0)
return ERR_PTR(err);
diff --git a/drivers/usb/typec/tcpm/tcpci.h b/drivers/usb/typec/tcpm/tcpci.h
index 5ef07a56d67a..406dfb53f492 100644
--- a/drivers/usb/typec/tcpm/tcpci.h
+++ b/drivers/usb/typec/tcpm/tcpci.h
@@ -8,6 +8,8 @@
#ifndef __LINUX_USB_TCPCI_H
#define __LINUX_USB_TCPCI_H
+#include <linux/usb/typec.h>
+
#define TCPC_VENDOR_ID 0x0
#define TCPC_PRODUCT_ID 0x2
#define TCPC_BCD_DEV 0x4
@@ -67,6 +69,7 @@
#define TCPC_POWER_CTRL 0x1c
#define TCPC_POWER_CTRL_VCONN_ENABLE BIT(0)
+#define TCPC_POWER_CTRL_AUTO_DISCHARGE BIT(4)
#define TCPC_FAST_ROLE_SWAP_EN BIT(7)
#define TCPC_CC_STATUS 0x1d
@@ -133,6 +136,8 @@
#define TCPC_VBUS_VOLTAGE 0x70
#define TCPC_VBUS_SINK_DISCONNECT_THRESH 0x72
+#define TCPC_VBUS_SINK_DISCONNECT_THRESH_LSB_MV 25
+#define TCPC_VBUS_SINK_DISCONNECT_THRESH_MAX 0x3ff
#define TCPC_VBUS_STOP_DISCHARGE_THRESH 0x74
#define TCPC_VBUS_VOLTAGE_ALARM_HI_CFG 0x76
#define TCPC_VBUS_VOLTAGE_ALARM_LO_CFG 0x78
@@ -140,20 +145,33 @@
/* I2C_WRITE_BYTE_COUNT + 1 when TX_BUF_BYTE_x is only accessible I2C_WRITE_BYTE_COUNT */
#define TCPC_TRANSMIT_BUFFER_MAX_LEN 31
+struct tcpci;
+
/*
- * @TX_BUF_BYTE_x_hidden
+ * @TX_BUF_BYTE_x_hidden:
* optional; Set when TX_BUF_BYTE_x can only be accessed through I2C_WRITE_BYTE_COUNT.
+ * @auto_discharge_disconnect:
+ * Optional; Enables TCPC to autonously discharge vbus on disconnect.
+ * @set_auto_vbus_discharge_threshold:
+ * Mandatory when @auto_discharge_disconnect is sets. Allows
+ * programming the voltage threshold of vbus below which TCPC
+ * enables the vbus discharge circuit.
*/
-struct tcpci;
struct tcpci_data {
struct regmap *regmap;
unsigned char TX_BUF_BYTE_x_hidden:1;
+ unsigned char auto_discharge_disconnect:1;
+
int (*init)(struct tcpci *tcpci, struct tcpci_data *data);
int (*set_vconn)(struct tcpci *tcpci, struct tcpci_data *data,
bool enable);
int (*start_drp_toggling)(struct tcpci *tcpci, struct tcpci_data *data,
enum typec_cc_status cc);
int (*set_vbus)(struct tcpci *tcpci, struct tcpci_data *data, bool source, bool sink);
+ u32 (*get_auto_vbus_discharge_threshold)(struct tcpci *tcpci, struct tcpci_data *data,
+ enum typec_role port_role,
+ enum typec_pwr_opmode mode, bool pps_active,
+ u32 requested_vbus_voltage);
};
struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);
--
2.28.0.681.g6f77f65b4e-goog
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