2020-10-29 09:01:32

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 00/10] TCPM support for FRS and AutoDischarge Disconnect

Hi all,

Addressed two comments in the series
1. From Rob Herring: Maxim parts are generally named 'maxim,max[0-9]+'
https://lkml.org/lkml/2020/10/26/503
Changed all occurences of maxim,33359 to maxim,max33359.

2. Added a new patch to address warnings reported by Kernel test robot.
https://www.mail-archive.com/[email protected]/msg2354139.html
usb: typec: tcpci_maxim: Fix smatch warnings

Heikki, now that Rob has reviewed the dts patches, the following patches
are ready to be reviewed as well:
usb: typec: tcpci_maxim: Fix the compatible string
usb: typec: tcpm: Refactor logic for new-source-frs-typec-current

Greatly appreciate all of your support reviewing the code.

Thanks,
Badhri.

Badhri Jagan Sridharan (10):
dt-bindings: usb: Maxim type-c controller device tree binding document
usb: typec: tcpci_maxim: Fix the compatible string
usb: typec: tcpm: Refactor logic for new-source-frs-typec-current
usb: typec: tcpm: frs sourcing vbus callback
usb: typec: tcpci: frs sourcing vbus callback
usb: typec: tcpci_maxim: Fix vbus stuck on upon diconnecting sink
usb: typec: tcpm: Implement enabling Auto Discharge disconnect support
usb: typec: tcpci: Implement Auto discharge disconnect callbacks
usb: typec: tcpci_maxim: Enable auto discharge disconnect
usb: typec: tcpci_maxim: Fix smatch warnings

.../bindings/usb/maxim,max33359.yaml | 75 ++++++++++++++++
drivers/usb/typec/tcpm/tcpci.c | 72 ++++++++++++++-
drivers/usb/typec/tcpm/tcpci.h | 18 +++-
drivers/usb/typec/tcpm/tcpci_maxim.c | 35 ++++----
drivers/usb/typec/tcpm/tcpm.c | 87 ++++++++++++++++---
include/linux/usb/tcpm.h | 19 ++++
6 files changed, 274 insertions(+), 32 deletions(-)
create mode 100644 Documentation/devicetree/bindings/usb/maxim,max33359.yaml


base-commit: aee9ddb1d3718d3ba05b50c51622d7792ae749c9
--
2.29.1.341.ge80a0c044ae-goog


2020-10-29 09:01:48

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 06/10] usb: typec: tcpci_maxim: Fix vbus stuck on upon diconnecting sink

Occasionally, POWER_STATUS.sourcing_vbus takes a while to clear after
writing to MAX_BUCK_BOOST_OP register. This causes vbus to turn back
on while disconnecting the sink. Overcome this issue by writing into
MAX_BUCK_BOOST_OP during frs while sourcing vbu, instead of always
into the register whenever POWER_STATUS.sourcing_vbus is set.

Signed-off-by: Badhri Jagan Sridharan <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
---
v9 is the first version of this patch. Added to fix
occasional bug of vbus turning back on when disconnecting the FRS accessory
after disconnect. No changes since v9.

Changes since v10:
Added Reviewed-by: Heikki Krogerus

Changes since v11:
none
---
drivers/usb/typec/tcpm/tcpci_maxim.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim.c
index a5014c3b51d5..dd6171604362 100644
--- a/drivers/usb/typec/tcpm/tcpci_maxim.c
+++ b/drivers/usb/typec/tcpm/tcpci_maxim.c
@@ -238,23 +238,22 @@ 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 if (pwr_status & TCPC_POWER_STATUS_SOURCING_VBUS) {
+ 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 {
+ else
tcpm_vbus_change(chip->port);
- }
+}
+
+static void max_tcpci_frs_sourcing_vbus(struct tcpci *tcpci, struct tcpci_data *tdata)
+{
+ /*
+ * 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(tcpci, tdata, true, false);
}

static void process_tx(struct max_tcpci_chip *chip, u16 status)
@@ -441,6 +440,7 @@ static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id
chip->data.start_drp_toggling = max_tcpci_start_toggling;
chip->data.TX_BUF_BYTE_x_hidden = true;
chip->data.init = tcpci_init;
+ chip->data.frs_sourcing_vbus = max_tcpci_frs_sourcing_vbus;

max_tcpci_init_regs(chip);
chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
--
2.29.1.341.ge80a0c044ae-goog

2020-10-29 09:02:29

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 02/10] usb: typec: tcpci_maxim: Fix the compatible string

Changing compatible string to include the part number.

Signed-off-by: Badhri Jagan Sridharan <[email protected]>
---
V11 is the first version of the patch.
Introduced to add chip number to the compatible property to address
Rob Herring's comment on dt-binding patch.

Change since v11:
Changed compatible property from maxim,33359 to maxim,max33359
to address Rob Herring's comment
---
drivers/usb/typec/tcpm/tcpci_maxim.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim.c
index 723d7dd38f75..a5014c3b51d5 100644
--- a/drivers/usb/typec/tcpm/tcpci_maxim.c
+++ b/drivers/usb/typec/tcpm/tcpci_maxim.c
@@ -481,7 +481,7 @@ MODULE_DEVICE_TABLE(i2c, max_tcpci_id);

#ifdef CONFIG_OF
static const struct of_device_id max_tcpci_of_match[] = {
- { .compatible = "maxim,tcpc", },
+ { .compatible = "maxim,max33359", },
{},
};
MODULE_DEVICE_TABLE(of, max_tcpci_of_match);
--
2.29.1.341.ge80a0c044ae-goog

2020-10-29 09:02:29

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 10/10] usb: typec: tcpci_maxim: Fix uninitialized return variable

New smatch warnings:
drivers/usb/typec/tcpm/tcpci_maxim.c:324 max_tcpci_irq() error: uninitialized symbol 'irq_return'.
drivers/usb/typec/tcpm/tcpci_maxim.c:407 max_tcpci_probe() warn: passing zero to 'PTR_ERR'

The change fixes the above warnings by initializing irq_return
and replacing IS_ERR_OR_NULL with IS_ERR.

Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Badhri Jagan Sridharan <[email protected]>
---
v12 is the first version of the patch in this series.
---
drivers/usb/typec/tcpm/tcpci_maxim.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim.c
index 536df4a7901a..c1797239bf08 100644
--- a/drivers/usb/typec/tcpm/tcpci_maxim.c
+++ b/drivers/usb/typec/tcpm/tcpci_maxim.c
@@ -343,7 +343,7 @@ static irqreturn_t max_tcpci_irq(int irq, void *dev_id)
{
struct max_tcpci_chip *chip = dev_id;
u16 status;
- irqreturn_t irq_return;
+ irqreturn_t irq_return = IRQ_HANDLED;
int ret;

if (!chip->port)
@@ -445,7 +445,7 @@ static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id

max_tcpci_init_regs(chip);
chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
- if (IS_ERR_OR_NULL(chip->tcpci)) {
+ if (IS_ERR(chip->tcpci)) {
dev_err(&client->dev, "TCPCI port registration failed");
ret = PTR_ERR(chip->tcpci);
return PTR_ERR(chip->tcpci);
--
2.29.1.341.ge80a0c044ae-goog

2020-10-29 09:03:27

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 05/10] usb: typec: tcpci: frs sourcing vbus callback

During FRS hardware autonomously starts to source vbus. Provide
callback to perform chip specific operations.

Signed-off-by: Badhri Jagan Sridharan <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
---
v9 is the first version of this patch in the series. Added to fix
occasional bug of vbus turning back on when disconnecting the FRS accessory
after disconnect. No changes since v9.

Changes since v10:
Added Reviewed-by: Heikki Krogerus

Changes since v11:
none
---
drivers/usb/typec/tcpm/tcpci.c | 9 +++++++++
drivers/usb/typec/tcpm/tcpci.h | 4 ++++
2 files changed, 13 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index f9f0af64da5f..f91688e43991 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -284,6 +284,14 @@ static int tcpci_enable_frs(struct tcpc_dev *dev, bool enable)
return ret;
}

+static void tcpci_frs_sourcing_vbus(struct tcpc_dev *dev)
+{
+ struct tcpci *tcpci = tcpc_to_tcpci(dev);
+
+ if (tcpci->data->frs_sourcing_vbus)
+ tcpci->data->frs_sourcing_vbus(tcpci, tcpci->data);
+}
+
static int tcpci_set_bist_data(struct tcpc_dev *tcpc, bool enable)
{
struct tcpci *tcpci = tcpc_to_tcpci(tcpc);
@@ -628,6 +636,7 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
tcpci->tcpc.pd_transmit = tcpci_pd_transmit;
tcpci->tcpc.set_bist_data = tcpci_set_bist_data;
tcpci->tcpc.enable_frs = tcpci_enable_frs;
+ tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;

err = tcpci_parse_config(tcpci);
if (err < 0)
diff --git a/drivers/usb/typec/tcpm/tcpci.h b/drivers/usb/typec/tcpm/tcpci.h
index 5ef07a56d67a..b418fe11b527 100644
--- a/drivers/usb/typec/tcpm/tcpci.h
+++ b/drivers/usb/typec/tcpm/tcpci.h
@@ -143,6 +143,9 @@
/*
* @TX_BUF_BYTE_x_hidden
* optional; Set when TX_BUF_BYTE_x can only be accessed through I2C_WRITE_BYTE_COUNT.
+ * @frs_sourcing_vbus:
+ * Optional; Callback to perform chip specific operations when FRS
+ * is sourcing vbus.
*/
struct tcpci;
struct tcpci_data {
@@ -154,6 +157,7 @@ struct tcpci_data {
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);
+ void (*frs_sourcing_vbus)(struct tcpci *tcpci, struct tcpci_data *data);
};

struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data);
--
2.29.1.341.ge80a0c044ae-goog

2020-10-29 09:04:13

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 04/10] usb: typec: tcpm: frs sourcing vbus callback

During FRS hardware autonomously starts to source vbus. Provide
callback to perform chip specific operations.

Signed-off-by: Badhri Jagan Sridharan <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
---
Introduced in v9.

Changes since v10:
Added Reviewed-by: Heikki Krogerus

Changes since v11:
none
---
drivers/usb/typec/tcpm/tcpm.c | 9 +++++++++
include/linux/usb/tcpm.h | 4 ++++
2 files changed, 13 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 561480b67bce..0123d2f14c96 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4091,7 +4091,16 @@ static void _tcpm_pd_vbus_on(struct tcpm_port *port)
case SRC_TRY_DEBOUNCE:
/* Do nothing, waiting for sink detection */
break;
+ case FR_SWAP_SEND:
+ case FR_SWAP_SEND_TIMEOUT:
+ case FR_SWAP_SNK_SRC_TRANSITION_TO_OFF:
+ case FR_SWAP_SNK_SRC_SOURCE_VBUS_APPLIED:
+ if (port->tcpc->frs_sourcing_vbus)
+ port->tcpc->frs_sourcing_vbus(port->tcpc);
+ break;
case FR_SWAP_SNK_SRC_NEW_SINK_READY:
+ if (port->tcpc->frs_sourcing_vbus)
+ port->tcpc->frs_sourcing_vbus(port->tcpc);
tcpm_set_state(port, FR_SWAP_SNK_SRC_SOURCE_VBUS_APPLIED, 0);
break;

diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
index 09762d26fa0c..7303f518ba49 100644
--- a/include/linux/usb/tcpm.h
+++ b/include/linux/usb/tcpm.h
@@ -83,6 +83,9 @@ enum tcpm_transmit_type {
* Optional; Called to enable/disable PD 3.0 fast role swap.
* Enabling frs is accessory dependent as not all PD3.0
* accessories support fast role swap.
+ * @frs_sourcing_vbus:
+ * Optional; Called to notify that vbus is now being sourced.
+ * Low level drivers can perform chip specific operations, if any.
*/
struct tcpc_dev {
struct fwnode_handle *fwnode;
@@ -109,6 +112,7 @@ struct tcpc_dev {
const struct pd_message *msg);
int (*set_bist_data)(struct tcpc_dev *dev, bool on);
int (*enable_frs)(struct tcpc_dev *dev, bool enable);
+ void (*frs_sourcing_vbus)(struct tcpc_dev *dev);
};

struct tcpm_port;
--
2.29.1.341.ge80a0c044ae-goog

2020-10-29 09:05:42

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 09/10] usb: typec: tcpci_maxim: Enable auto discharge disconnect

Enable auto discharge disconnect for Maxim TCPC.

Signed-off-by: Badhri Jagan Sridharan <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
---
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 of TCPC_VBUS_SINK_DISCONNECT_THRES
register to tcpci code.

Changes since v8:
- Moved the logic to program the default values of
TCPC_VBUS_SINK_DISCONNECT_THRESH into the tcpci code.

Changes since v9:
- none.

Changes since v10:
-Added Reviewed-by: Heikki Krogerus

Changes since v11:
none
---
drivers/usb/typec/tcpm/tcpci_maxim.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim.c
index dd6171604362..536df4a7901a 100644
--- a/drivers/usb/typec/tcpm/tcpci_maxim.c
+++ b/drivers/usb/typec/tcpm/tcpci_maxim.c
@@ -441,6 +441,7 @@ static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id
chip->data.TX_BUF_BYTE_x_hidden = true;
chip->data.init = tcpci_init;
chip->data.frs_sourcing_vbus = max_tcpci_frs_sourcing_vbus;
+ chip->data.auto_discharge_disconnect = true;

max_tcpci_init_regs(chip);
chip->tcpci = tcpci_register_port(chip->dev, &chip->data);
--
2.29.1.341.ge80a0c044ae-goog

2020-10-29 09:05:47

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 07/10] usb: typec: tcpm: Implement enabling Auto Discharge disconnect support

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 <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
---
Changes since v1:
- Changing patch version to v6 to fix version number confusion.

Changes since v6:
- Fixed incorrect data_role error that I introduced by mistake in
the previous version.

Changes since v7:
- Rebase on usb-next

Changes since v8:
- Removing the call to tcpm_set_auto_vbus_discharge_threshold
in the source path.

Changes since v9:
- None

Changes since v10:
Added Reviewed-by: Heikki Krogerus

Changes since v11:
none
---
drivers/usb/typec/tcpm/tcpm.c | 60 ++++++++++++++++++++++++++++++++---
include/linux/usb/tcpm.h | 15 +++++++++
2 files changed, 71 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 0123d2f14c96..1539faf06d38 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -1706,6 +1706,24 @@ static void tcpm_handle_alert(struct tcpm_port *port, const __le32 *payload,
}
}

+static int tcpm_set_auto_vbus_discharge_threshold(struct tcpm_port *port,
+ enum typec_pwr_opmode mode, bool pps_active,
+ u32 requested_vbus_voltage)
+{
+ int ret;
+
+ if (!port->tcpc->set_auto_vbus_discharge_threshold)
+ return 0;
+
+ ret = port->tcpc->set_auto_vbus_discharge_threshold(port->tcpc, mode, pps_active,
+ requested_vbus_voltage);
+ tcpm_log_force(port,
+ "set_auto_vbus_discharge_threshold mode:%d pps_active:%c vbus:%u ret:%d",
+ mode, pps_active ? 'y' : 'n', requested_vbus_voltage, ret);
+
+ return ret;
+}
+
static void tcpm_pd_data_request(struct tcpm_port *port,
const struct pd_message *msg)
{
@@ -1876,6 +1894,10 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
port->current_limit,
port->supply_voltage);
port->explicit_contract = true;
+ tcpm_set_auto_vbus_discharge_threshold(port,
+ TYPEC_PWR_MODE_PD,
+ port->pps_data.active,
+ port->supply_voltage);
tcpm_set_state(port, SNK_READY, 0);
} else {
/*
@@ -2790,8 +2812,12 @@ static int tcpm_src_attach(struct tcpm_port *port)
if (ret < 0)
return ret;

- ret = tcpm_set_roles(port, true, TYPEC_SOURCE,
- tcpm_data_role_for_source(port));
+ if (port->tcpc->enable_auto_vbus_discharge) {
+ ret = port->tcpc->enable_auto_vbus_discharge(port->tcpc, true);
+ tcpm_log_force(port, "enable vbus discharge ret:%d", ret);
+ }
+
+ ret = tcpm_set_roles(port, true, TYPEC_SOURCE, tcpm_data_role_for_source(port));
if (ret < 0)
return ret;

@@ -2858,6 +2884,12 @@ static void tcpm_unregister_altmodes(struct tcpm_port *port)

static void tcpm_reset_port(struct tcpm_port *port)
{
+ int ret;
+
+ if (port->tcpc->enable_auto_vbus_discharge) {
+ ret = port->tcpc->enable_auto_vbus_discharge(port->tcpc, false);
+ tcpm_log_force(port, "Disable vbus discharge ret:%d", ret);
+ }
tcpm_unregister_altmodes(port);
tcpm_typec_disconnect(port);
port->attached = false;
@@ -2922,8 +2954,13 @@ static int tcpm_snk_attach(struct tcpm_port *port)
if (ret < 0)
return ret;

- ret = tcpm_set_roles(port, true, TYPEC_SINK,
- tcpm_data_role_for_sink(port));
+ if (port->tcpc->enable_auto_vbus_discharge) {
+ tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, VSAFE5V);
+ ret = port->tcpc->enable_auto_vbus_discharge(port->tcpc, true);
+ tcpm_log_force(port, "enable vbus discharge ret:%d", ret);
+ }
+
+ ret = tcpm_set_roles(port, true, TYPEC_SINK, tcpm_data_role_for_sink(port));
if (ret < 0)
return ret;

@@ -3507,6 +3544,8 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_state(port, SRC_UNATTACHED, PD_T_PS_SOURCE_ON);
break;
case SNK_HARD_RESET_SINK_OFF:
+ /* Do not discharge/disconnect during hard reseet */
+ tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, 0);
memset(&port->pps_data, 0, sizeof(port->pps_data));
tcpm_set_vconn(port, false);
if (port->pd_capable)
@@ -3549,6 +3588,7 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_charge(port, true);
}
tcpm_set_attached_state(port, true);
+ tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, VSAFE5V);
tcpm_set_state(port, SNK_STARTUP, 0);
break;

@@ -3650,6 +3690,10 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_state(port, PR_SWAP_SNK_SRC_SINK_OFF, 0);
break;
case PR_SWAP_SRC_SNK_TRANSITION_OFF:
+ /*
+ * Prevent vbus discharge circuit from turning on during PR_SWAP
+ * as this is not a disconnect.
+ */
tcpm_set_vbus(port, false);
port->explicit_contract = false;
/* allow time for Vbus discharge, must be < tSrcSwapStdby */
@@ -3678,9 +3722,17 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_state_cond(port, SNK_UNATTACHED, PD_T_PS_SOURCE_ON);
break;
case PR_SWAP_SRC_SNK_SINK_ON:
+ /* Set the vbus disconnect threshold for implicit contract */
+ tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, VSAFE5V);
tcpm_set_state(port, SNK_STARTUP, 0);
break;
case PR_SWAP_SNK_SRC_SINK_OFF:
+ /*
+ * Prevent vbus discharge circuit from turning on during PR_SWAP
+ * as this is not a disconnect.
+ */
+ tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB,
+ port->pps_data.active, 0);
tcpm_set_charge(port, false);
tcpm_set_state(port, hard_reset_state(port),
PD_T_PS_SOURCE_OFF);
diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
index 7303f518ba49..e68aaa12886f 100644
--- a/include/linux/usb/tcpm.h
+++ b/include/linux/usb/tcpm.h
@@ -86,6 +86,18 @@ enum tcpm_transmit_type {
* @frs_sourcing_vbus:
* Optional; Called to notify that vbus is now being sourced.
* Low level drivers can perform chip specific operations, if any.
+ * @enable_auto_vbus_discharge:
+ * Optional; TCPCI spec based TCPC implementations can optionally
+ * support hardware to autonomously dischrge vbus upon disconnecting
+ * as sink or source. TCPM signals TCPC to enable the mechanism upon
+ * entering connected state and signals disabling upon disconnect.
+ * @set_auto_vbus_discharge_threshold:
+ * Mandatory when enable_auto_vbus_discharge is implemented. TCPM
+ * calls this function to allow lower levels drivers to program the
+ * vbus threshold voltage below which the vbus discharge circuit
+ * will be turned on. requested_vbus_voltage is set to 0 when vbus
+ * is going to disappear knowingly i.e. during PR_SWAP and
+ * HARD_RESET etc.
*/
struct tcpc_dev {
struct fwnode_handle *fwnode;
@@ -113,6 +125,9 @@ struct tcpc_dev {
int (*set_bist_data)(struct tcpc_dev *dev, bool on);
int (*enable_frs)(struct tcpc_dev *dev, bool enable);
void (*frs_sourcing_vbus)(struct tcpc_dev *dev);
+ int (*enable_auto_vbus_discharge)(struct tcpc_dev *dev, bool enable);
+ int (*set_auto_vbus_discharge_threshold)(struct tcpc_dev *dev, enum typec_pwr_opmode mode,
+ bool pps_active, u32 requested_vbus_voltage);
};

struct tcpm_port;
--
2.29.1.341.ge80a0c044ae-goog

2020-10-29 09:05:50

by Badhri Jagan Sridharan

[permalink] [raw]
Subject: [PATCH v12 08/10] usb: typec: tcpci: Implement Auto discharge disconnect callbacks

vImplement callbacks for enabling/disabling
POWER_CONTROL.AutoDischargeDisconnect.

Programs VBUS_SINK_DISCONNECT_THRESHOLD based on the
voltage requested as sink, mode of operation.

The programmed threshold is based on vSinkDisconnect and
vSinkDisconnectPD values.

Add auto_discharge_disconnect to tdata to allow TCPC chip
level drivers enable AutoDischargeDisconnect.

Signed-off-by: Badhri Jagan Sridharan <[email protected]>
Reviewed-by: Heikki Krogerus <[email protected]>
---
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

Changes since v8:
- Removed get_auto_vbus_discharge_threshold callback and moved the logic
to program the default threshold for TCPC_VBUS_SINK_DISCONNECT_THRESH
into the TCPCI code.

Changes since v9:
- none

Changes since v10:
-Added Reviewed-by: Heikki Krogerus

Changes since v11:
none
---
drivers/usb/typec/tcpm/tcpci.c | 63 +++++++++++++++++++++++++++++++++-
drivers/usb/typec/tcpm/tcpci.h | 14 ++++++--
2 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index f91688e43991..12d983a75510 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -18,7 +18,10 @@

#include "tcpci.h"

-#define PD_RETRY_COUNT 3
+#define PD_RETRY_COUNT 3
+#define AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV 3500
+#define AUTO_DISCHARGE_PD_HEADROOM_MV 850
+#define AUTO_DISCHARGE_PPS_HEADROOM_MV 1250

struct tcpci {
struct device *dev;
@@ -268,6 +271,58 @@ 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_pwr_opmode mode,
+ bool pps_active, u32 requested_vbus_voltage_mv)
+{
+ struct tcpci *tcpci = tcpc_to_tcpci(dev);
+ unsigned int pwr_ctrl, threshold = 0;
+ int ret;
+
+ /*
+ * Indicates that vbus is going to go away due PR_SWAP, hard reset etc.
+ * Do not discharge vbus here.
+ */
+ if (requested_vbus_voltage_mv == 0)
+ goto write_thresh;
+
+ ret = regmap_read(tcpci->regmap, TCPC_POWER_CTRL, &pwr_ctrl);
+ if (ret < 0)
+ return ret;
+
+ if (pwr_ctrl & TCPC_FAST_ROLE_SWAP_EN) {
+ /* To prevent disconnect when the source is fast role swap is capable. */
+ threshold = AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV;
+ } else if (mode == TYPEC_PWR_MODE_PD) {
+ if (pps_active)
+ threshold = (95 * requested_vbus_voltage_mv / 100) -
+ AUTO_DISCHARGE_PD_HEADROOM_MV;
+ else
+ threshold = (95 * requested_vbus_voltage_mv / 100) -
+ AUTO_DISCHARGE_PPS_HEADROOM_MV;
+ } else {
+ /* 3.5V for non-pd sink */
+ threshold = AUTO_DISCHARGE_DEFAULT_THRESHOLD_MV;
+ }
+
+ threshold = threshold / TCPC_VBUS_SINK_DISCONNECT_THRESH_LSB_MV;
+
+ if (threshold > TCPC_VBUS_SINK_DISCONNECT_THRESH_MAX)
+ return -EINVAL;
+
+write_thresh:
+ return tcpci_write16(tcpci, TCPC_VBUS_SINK_DISCONNECT_THRESH, threshold);
+}
+
static int tcpci_enable_frs(struct tcpc_dev *dev, bool enable)
{
struct tcpci *tcpci = tcpc_to_tcpci(dev);
@@ -638,6 +693,12 @@ struct tcpci *tcpci_register_port(struct device *dev, struct tcpci_data *data)
tcpci->tcpc.enable_frs = tcpci_enable_frs;
tcpci->tcpc.frs_sourcing_vbus = tcpci_frs_sourcing_vbus;

+ 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 b418fe11b527..3fe313655f0c 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
@@ -140,17 +145,22 @@
/* 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.
* @frs_sourcing_vbus:
* Optional; Callback to perform chip specific operations when FRS
* is sourcing vbus.
+ * @auto_discharge_disconnect:
+ * Optional; Enables TCPC to autonously discharge vbus on disconnect.
*/
-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);
--
2.29.1.341.ge80a0c044ae-goog