2021-07-27 15:14:12

by Kyle Tso

[permalink] [raw]
Subject: [PATCH v2 0/2] TCPM non-pd mode

The reason for this patch is to let the device/system policy decide
whether PD is going to be supported using devicetree properties.

A new dt property "pd-supported" is introduced and TCPM uses this
property as a flag to decide whether PD is supported. If the flag is
false, the RX functionality of the low-level driver will not be enabled.
The power negotiation related states will be skipped as well. If the
flag is true, everything is as what it was before.

If "pd-supported" is not present, and the port is SRC or DRP, another
existing dt property "typec-power-opmode" needs to be specified to
indicate which Rp value should be used when the port is SRC.

changes since v1:
- revise the patch to use dt properties

Kyle Tso (2):
dt-bindings: connector: Add pd-supported property
usb: typec: tcpm: Support non-PD mode

.../bindings/connector/usb-connector.yaml | 5 +
drivers/usb/typec/tcpm/tcpm.c | 108 +++++++++++++-----
2 files changed, 84 insertions(+), 29 deletions(-)

--
2.32.0.432.gabb21c7263-goog



2021-07-27 15:14:33

by Kyle Tso

[permalink] [raw]
Subject: [PATCH v2 2/2] usb: typec: tcpm: Support non-PD mode

Even if the Type-C controller supports PD, it is doable to disable PD
capabilities with the current state machine in TCPM. Without enabling RX
in low-level drivers and with skipping the power negotiation, the port
is eligible to be a non-PD Type-C port. Use new flags whose values are
populated from the device tree to decide the port PD capability. Adding
"pd-supported" property in device tree indicates that the port supports
PD. If "pd-supported" is not found, "typec-power-opmode" shall be added
to specify the advertised Rp value if the port supports SRC role.

Signed-off-by: Kyle Tso <[email protected]>
---
changes since v1:
- Revised the patch to use dt properties
- Added back the checks of callbacks set_pd_rx and pd_transmit
- Added src_rp to indicate which Rp value should be used in SRC. This
variable is derived from dt property "typec-power-opmode"

drivers/usb/typec/tcpm/tcpm.c | 108 +++++++++++++++++++++++++---------
1 file changed, 79 insertions(+), 29 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 5b22a1c931a9..4cf77c787f54 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -316,6 +316,7 @@ struct tcpm_port {
struct typec_partner *partner;

enum typec_cc_status cc_req;
+ enum typec_cc_status src_rp; /* work only if pd_supported == false */

enum typec_cc_status cc1;
enum typec_cc_status cc2;
@@ -323,6 +324,7 @@ struct tcpm_port {

bool attached;
bool connected;
+ bool pd_supported;
enum typec_port_type port_type;

/*
@@ -804,6 +806,7 @@ static void tcpm_apply_rc(struct tcpm_port *port)
}
}

+
/*
* Determine RP value to set based on maximum current supported
* by a port if configured as source.
@@ -815,6 +818,9 @@ static enum typec_cc_status tcpm_rp_cc(struct tcpm_port *port)
int nr_pdo = port->nr_src_pdo;
int i;

+ if (!port->pd_supported)
+ return port->src_rp;
+
/*
* Search for first entry with matching voltage.
* It should report the maximum supported current.
@@ -3568,9 +3574,11 @@ static int tcpm_src_attach(struct tcpm_port *port)
if (ret < 0)
return ret;

- ret = port->tcpc->set_pd_rx(port->tcpc, true);
- if (ret < 0)
- goto out_disable_mux;
+ if (port->pd_supported) {
+ ret = port->tcpc->set_pd_rx(port->tcpc, true);
+ if (ret < 0)
+ goto out_disable_mux;
+ }

/*
* USB Type-C specification, version 1.2,
@@ -3600,7 +3608,8 @@ static int tcpm_src_attach(struct tcpm_port *port)
out_disable_vconn:
tcpm_set_vconn(port, false);
out_disable_pd:
- port->tcpc->set_pd_rx(port->tcpc, false);
+ if (port->pd_supported)
+ port->tcpc->set_pd_rx(port->tcpc, false);
out_disable_mux:
tcpm_mux_set(port, TYPEC_STATE_SAFE, USB_ROLE_NONE,
TYPEC_ORIENTATION_NONE);
@@ -3804,6 +3813,20 @@ static enum typec_pwr_opmode tcpm_get_pwr_opmode(enum typec_cc_status cc)
}
}

+static enum typec_cc_status tcpm_pwr_opmode_to_rp(enum typec_pwr_opmode opmode)
+{
+ switch (opmode) {
+ case TYPEC_PWR_MODE_USB:
+ return TYPEC_CC_RP_DEF;
+ case TYPEC_PWR_MODE_1_5A:
+ return TYPEC_CC_RP_1_5;
+ case TYPEC_PWR_MODE_3_0A:
+ case TYPEC_PWR_MODE_PD:
+ default:
+ return TYPEC_CC_RP_3_0;
+ }
+}
+
static void run_state_machine(struct tcpm_port *port)
{
int ret;
@@ -3914,6 +3937,10 @@ static void run_state_machine(struct tcpm_port *port)
if (port->ams == POWER_ROLE_SWAP ||
port->ams == FAST_ROLE_SWAP)
tcpm_ams_finish(port);
+ if (!port->pd_supported) {
+ tcpm_set_state(port, SRC_READY, 0);
+ break;
+ }
port->upcoming_state = SRC_SEND_CAPABILITIES;
tcpm_ams_start(port, POWER_NEGOTIATION);
break;
@@ -4161,7 +4188,10 @@ static void run_state_machine(struct tcpm_port *port)
current_lim = PD_P_SNK_STDBY_MW / 5;
tcpm_set_current_limit(port, current_lim, 5000);
tcpm_set_charge(port, true);
- tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
+ if (!port->pd_supported)
+ tcpm_set_state(port, SNK_READY, 0);
+ else
+ tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
break;
}
/*
@@ -4389,7 +4419,8 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_vbus(port, true);
if (port->ams == HARD_RESET)
tcpm_ams_finish(port);
- port->tcpc->set_pd_rx(port->tcpc, true);
+ if (port->pd_supported)
+ port->tcpc->set_pd_rx(port->tcpc, true);
tcpm_set_attached_state(port, true);
tcpm_set_state(port, SRC_UNATTACHED, PD_T_PS_SOURCE_ON);
break;
@@ -5898,6 +5929,7 @@ EXPORT_SYMBOL_GPL(tcpm_tcpc_reset);
static int tcpm_fw_get_caps(struct tcpm_port *port,
struct fwnode_handle *fwnode)
{
+ const char *opmode_str;
const char *cap_str;
int ret;
u32 mw, frs_current;
@@ -5932,22 +5964,36 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
return ret;
port->typec_caps.type = ret;
port->port_type = port->typec_caps.type;
+ port->pd_supported = fwnode_property_read_bool(fwnode, "pd-supported");

port->slow_charger_loop = fwnode_property_read_bool(fwnode, "slow-charger-loop");
if (port->port_type == TYPEC_PORT_SNK)
goto sink;

/* Get source pdos */
- ret = fwnode_property_count_u32(fwnode, "source-pdos");
- if (ret <= 0)
- return -EINVAL;
+ if (port->pd_supported) {
+ ret = fwnode_property_count_u32(fwnode, "source-pdos");
+ if (ret <= 0)
+ return -EINVAL;

- port->nr_src_pdo = min(ret, PDO_MAX_OBJECTS);
- ret = fwnode_property_read_u32_array(fwnode, "source-pdos",
- port->src_pdo, port->nr_src_pdo);
- if ((ret < 0) || tcpm_validate_caps(port, port->src_pdo,
- port->nr_src_pdo))
- return -EINVAL;
+ port->nr_src_pdo = min(ret, PDO_MAX_OBJECTS);
+ ret = fwnode_property_read_u32_array(fwnode, "source-pdos",
+ port->src_pdo, port->nr_src_pdo);
+ if ((ret < 0) || tcpm_validate_caps(port, port->src_pdo,
+ port->nr_src_pdo))
+ return -EINVAL;
+ } else {
+ port->nr_src_pdo = 0;
+ ret = fwnode_property_read_string(fwnode, "typec-power-opmode", &opmode_str);
+ if (ret == 0) {
+ ret = typec_find_pwr_opmode(opmode_str);
+ if (ret < 0)
+ return ret;
+ port->src_rp = tcpm_pwr_opmode_to_rp(ret);
+ } else {
+ return ret;
+ }
+ }

if (port->port_type == TYPEC_PORT_SRC)
return 0;
@@ -5962,25 +6008,29 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
return -EINVAL;
sink:
/* Get sink pdos */
- ret = fwnode_property_count_u32(fwnode, "sink-pdos");
- if (ret <= 0)
- return -EINVAL;
+ if (port->pd_supported) {
+ ret = fwnode_property_count_u32(fwnode, "sink-pdos");
+ if (ret <= 0)
+ return -EINVAL;

- port->nr_snk_pdo = min(ret, PDO_MAX_OBJECTS);
- ret = fwnode_property_read_u32_array(fwnode, "sink-pdos",
- port->snk_pdo, port->nr_snk_pdo);
- if ((ret < 0) || tcpm_validate_caps(port, port->snk_pdo,
- port->nr_snk_pdo))
- return -EINVAL;
+ port->nr_snk_pdo = min(ret, PDO_MAX_OBJECTS);
+ ret = fwnode_property_read_u32_array(fwnode, "sink-pdos",
+ port->snk_pdo, port->nr_snk_pdo);
+ if ((ret < 0) || tcpm_validate_caps(port, port->snk_pdo,
+ port->nr_snk_pdo))
+ return -EINVAL;

- if (fwnode_property_read_u32(fwnode, "op-sink-microwatt", &mw) < 0)
- return -EINVAL;
- port->operating_snk_mw = mw / 1000;
+ if (fwnode_property_read_u32(fwnode, "op-sink-microwatt", &mw) < 0)
+ return -EINVAL;
+ port->operating_snk_mw = mw / 1000;
+ } else {
+ port->nr_snk_pdo = 0;
+ }

port->self_powered = fwnode_property_read_bool(fwnode, "self-powered");

- /* FRS can only be supported byb DRP ports */
- if (port->port_type == TYPEC_PORT_DRP) {
+ /* FRS can only be supported by DRP ports */
+ if (port->port_type == TYPEC_PORT_DRP && port->pd_supported) {
ret = fwnode_property_read_u32(fwnode, "new-source-frs-typec-current",
&frs_current);
if (ret >= 0 && frs_current <= FRS_5V_3A)
--
2.32.0.432.gabb21c7263-goog


2021-07-27 15:15:49

by Kyle Tso

[permalink] [raw]
Subject: [PATCH v2 1/2] dt-bindings: connector: Add pd-supported property

Set pd-supported property if the Type-C connector has power delivery
support.

Signed-off-by: Kyle Tso <[email protected]>
---
.../devicetree/bindings/connector/usb-connector.yaml | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml
index 92b49bc37939..8ed271feea08 100644
--- a/Documentation/devicetree/bindings/connector/usb-connector.yaml
+++ b/Documentation/devicetree/bindings/connector/usb-connector.yaml
@@ -111,6 +111,10 @@ properties:
- 1.5A
- 3.0A

+ pd-supported:
+ description: Set this property if the Type-C connector has power delivery support.
+ type: boolean
+
# The following are optional properties for "usb-c-connector" with power
# delivery support.
source-pdos:
@@ -312,6 +316,7 @@ examples:
label = "USB-C";
power-role = "dual";
try-power-role = "sink";
+ pd-supported;
source-pdos = <PDO_FIXED(5000, 2000, PDO_FIXED_USB_COMM)>;
sink-pdos = <PDO_FIXED(5000, 2000, PDO_FIXED_USB_COMM)
PDO_VAR(5000, 12000, 2000)>;
--
2.32.0.432.gabb21c7263-goog


2021-07-27 16:30:39

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] dt-bindings: connector: Add pd-supported property

On 7/27/21 8:13 AM, Kyle Tso wrote:
> Set pd-supported property if the Type-C connector has power delivery
> support.
>
> Signed-off-by: Kyle Tso <[email protected]>
> ---
> .../devicetree/bindings/connector/usb-connector.yaml | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml
> index 92b49bc37939..8ed271feea08 100644
> --- a/Documentation/devicetree/bindings/connector/usb-connector.yaml
> +++ b/Documentation/devicetree/bindings/connector/usb-connector.yaml
> @@ -111,6 +111,10 @@ properties:
> - 1.5A
> - 3.0A
>
> + pd-supported:

I think that would have to be a property indicating that pd is _not_
supported, for compatibility reasons. Otherwise all existing bindings
would indicate that pd is not supported.

> + description: Set this property if the Type-C connector has power delivery support.
> + type: boolean
> +
> # The following are optional properties for "usb-c-connector" with power
> # delivery support.
> source-pdos:
> @@ -312,6 +316,7 @@ examples:
> label = "USB-C";
> power-role = "dual";
> try-power-role = "sink";
> + pd-supported;
> source-pdos = <PDO_FIXED(5000, 2000, PDO_FIXED_USB_COMM)>;
> sink-pdos = <PDO_FIXED(5000, 2000, PDO_FIXED_USB_COMM)
> PDO_VAR(5000, 12000, 2000)>;
>


2021-07-27 22:48:04

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] usb: typec: tcpm: Support non-PD mode

On 7/27/21 8:13 AM, Kyle Tso wrote:
> Even if the Type-C controller supports PD, it is doable to disable PD
> capabilities with the current state machine in TCPM. Without enabling RX
> in low-level drivers and with skipping the power negotiation, the port
> is eligible to be a non-PD Type-C port. Use new flags whose values are
> populated from the device tree to decide the port PD capability. Adding
> "pd-supported" property in device tree indicates that the port supports
> PD. If "pd-supported" is not found, "typec-power-opmode" shall be added
> to specify the advertised Rp value if the port supports SRC role.
>
> Signed-off-by: Kyle Tso <[email protected]>
> ---
> changes since v1:
> - Revised the patch to use dt properties
> - Added back the checks of callbacks set_pd_rx and pd_transmit
> - Added src_rp to indicate which Rp value should be used in SRC. This
> variable is derived from dt property "typec-power-opmode"
>
> drivers/usb/typec/tcpm/tcpm.c | 108 +++++++++++++++++++++++++---------
> 1 file changed, 79 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 5b22a1c931a9..4cf77c787f54 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -316,6 +316,7 @@ struct tcpm_port {
> struct typec_partner *partner;
>
> enum typec_cc_status cc_req;
> + enum typec_cc_status src_rp; /* work only if pd_supported == false */
>
> enum typec_cc_status cc1;
> enum typec_cc_status cc2;
> @@ -323,6 +324,7 @@ struct tcpm_port {
>
> bool attached;
> bool connected;
> + bool pd_supported;
> enum typec_port_type port_type;
>
> /*
> @@ -804,6 +806,7 @@ static void tcpm_apply_rc(struct tcpm_port *port)
> }
> }
>
> +
> /*
> * Determine RP value to set based on maximum current supported
> * by a port if configured as source.
> @@ -815,6 +818,9 @@ static enum typec_cc_status tcpm_rp_cc(struct tcpm_port *port)
> int nr_pdo = port->nr_src_pdo;
> int i;
>
> + if (!port->pd_supported)
> + return port->src_rp;
> +
> /*
> * Search for first entry with matching voltage.
> * It should report the maximum supported current.
> @@ -3568,9 +3574,11 @@ static int tcpm_src_attach(struct tcpm_port *port)
> if (ret < 0)
> return ret;
>
> - ret = port->tcpc->set_pd_rx(port->tcpc, true);
> - if (ret < 0)
> - goto out_disable_mux;
> + if (port->pd_supported) {
> + ret = port->tcpc->set_pd_rx(port->tcpc, true);
> + if (ret < 0)
> + goto out_disable_mux;
> + }
>
> /*
> * USB Type-C specification, version 1.2,
> @@ -3600,7 +3608,8 @@ static int tcpm_src_attach(struct tcpm_port *port)
> out_disable_vconn:
> tcpm_set_vconn(port, false);
> out_disable_pd:
> - port->tcpc->set_pd_rx(port->tcpc, false);
> + if (port->pd_supported)
> + port->tcpc->set_pd_rx(port->tcpc, false);
> out_disable_mux:
> tcpm_mux_set(port, TYPEC_STATE_SAFE, USB_ROLE_NONE,
> TYPEC_ORIENTATION_NONE);
> @@ -3804,6 +3813,20 @@ static enum typec_pwr_opmode tcpm_get_pwr_opmode(enum typec_cc_status cc)
> }
> }
>
> +static enum typec_cc_status tcpm_pwr_opmode_to_rp(enum typec_pwr_opmode opmode)
> +{
> + switch (opmode) {
> + case TYPEC_PWR_MODE_USB:
> + return TYPEC_CC_RP_DEF;
> + case TYPEC_PWR_MODE_1_5A:
> + return TYPEC_CC_RP_1_5;
> + case TYPEC_PWR_MODE_3_0A:
> + case TYPEC_PWR_MODE_PD:
> + default:
> + return TYPEC_CC_RP_3_0;
> + }
> +}
> +
> static void run_state_machine(struct tcpm_port *port)
> {
> int ret;
> @@ -3914,6 +3937,10 @@ static void run_state_machine(struct tcpm_port *port)
> if (port->ams == POWER_ROLE_SWAP ||
> port->ams == FAST_ROLE_SWAP)
> tcpm_ams_finish(port);
> + if (!port->pd_supported) {
> + tcpm_set_state(port, SRC_READY, 0);
> + break;
> + }
> port->upcoming_state = SRC_SEND_CAPABILITIES;
> tcpm_ams_start(port, POWER_NEGOTIATION);
> break;
> @@ -4161,7 +4188,10 @@ static void run_state_machine(struct tcpm_port *port)
> current_lim = PD_P_SNK_STDBY_MW / 5;
> tcpm_set_current_limit(port, current_lim, 5000);
> tcpm_set_charge(port, true);
> - tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
> + if (!port->pd_supported)
> + tcpm_set_state(port, SNK_READY, 0);
> + else
> + tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
> break;
> }
> /*
> @@ -4389,7 +4419,8 @@ static void run_state_machine(struct tcpm_port *port)
> tcpm_set_vbus(port, true);
> if (port->ams == HARD_RESET)
> tcpm_ams_finish(port);
> - port->tcpc->set_pd_rx(port->tcpc, true);
> + if (port->pd_supported)
> + port->tcpc->set_pd_rx(port->tcpc, true);
> tcpm_set_attached_state(port, true);
> tcpm_set_state(port, SRC_UNATTACHED, PD_T_PS_SOURCE_ON);
> break;
> @@ -5898,6 +5929,7 @@ EXPORT_SYMBOL_GPL(tcpm_tcpc_reset);
> static int tcpm_fw_get_caps(struct tcpm_port *port,
> struct fwnode_handle *fwnode)
> {
> + const char *opmode_str;
> const char *cap_str;
> int ret;
> u32 mw, frs_current;
> @@ -5932,22 +5964,36 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
> return ret;
> port->typec_caps.type = ret;
> port->port_type = port->typec_caps.type;
> + port->pd_supported = fwnode_property_read_bool(fwnode, "pd-supported");
>

As mentioned in the other patch, I think this needs to be negated.
Not the variable itself, but the meaning of the property.

> port->slow_charger_loop = fwnode_property_read_bool(fwnode, "slow-charger-loop");

It might make sense to move the properties needed with !pd_supported to here
and return immediately after they are read. This would reduce the number of
required changes and avoid trying to read irrelevant properties.
Something like

if (port->port_type != TYPEC_PORT_SRC)
port->self_powered = fwnode_property_read_bool(fwnode, "self-powered");

if (!port->pd_supported)
return 0;

> if (port->port_type == TYPEC_PORT_SNK)
> goto sink;
>
> /* Get source pdos */
> - ret = fwnode_property_count_u32(fwnode, "source-pdos");
> - if (ret <= 0)
> - return -EINVAL;
> + if (port->pd_supported) {
> + ret = fwnode_property_count_u32(fwnode, "source-pdos");
> + if (ret <= 0)
> + return -EINVAL;
>
> - port->nr_src_pdo = min(ret, PDO_MAX_OBJECTS);
> - ret = fwnode_property_read_u32_array(fwnode, "source-pdos",
> - port->src_pdo, port->nr_src_pdo);
> - if ((ret < 0) || tcpm_validate_caps(port, port->src_pdo,
> - port->nr_src_pdo))
> - return -EINVAL;
> + port->nr_src_pdo = min(ret, PDO_MAX_OBJECTS);
> + ret = fwnode_property_read_u32_array(fwnode, "source-pdos",
> + port->src_pdo, port->nr_src_pdo);
> + if ((ret < 0) || tcpm_validate_caps(port, port->src_pdo,
> + port->nr_src_pdo))
> + return -EINVAL;
> + } else {
> + port->nr_src_pdo = 0;
> + ret = fwnode_property_read_string(fwnode, "typec-power-opmode", &opmode_str);
> + if (ret == 0) {
> + ret = typec_find_pwr_opmode(opmode_str);
> + if (ret < 0)
> + return ret;
> + port->src_rp = tcpm_pwr_opmode_to_rp(ret);
> + } else {
> + return ret;
> + }
> + }
>
> if (port->port_type == TYPEC_PORT_SRC)
> return 0;
> @@ -5962,25 +6008,29 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
> return -EINVAL;
> sink:
> /* Get sink pdos */
> - ret = fwnode_property_count_u32(fwnode, "sink-pdos");
> - if (ret <= 0)
> - return -EINVAL;
> + if (port->pd_supported) {
> + ret = fwnode_property_count_u32(fwnode, "sink-pdos");
> + if (ret <= 0)
> + return -EINVAL;
>
> - port->nr_snk_pdo = min(ret, PDO_MAX_OBJECTS);
> - ret = fwnode_property_read_u32_array(fwnode, "sink-pdos",
> - port->snk_pdo, port->nr_snk_pdo);
> - if ((ret < 0) || tcpm_validate_caps(port, port->snk_pdo,
> - port->nr_snk_pdo))
> - return -EINVAL;
> + port->nr_snk_pdo = min(ret, PDO_MAX_OBJECTS);
> + ret = fwnode_property_read_u32_array(fwnode, "sink-pdos",
> + port->snk_pdo, port->nr_snk_pdo);
> + if ((ret < 0) || tcpm_validate_caps(port, port->snk_pdo,
> + port->nr_snk_pdo))
> + return -EINVAL;
>
> - if (fwnode_property_read_u32(fwnode, "op-sink-microwatt", &mw) < 0)
> - return -EINVAL;
> - port->operating_snk_mw = mw / 1000;
> + if (fwnode_property_read_u32(fwnode, "op-sink-microwatt", &mw) < 0)
> + return -EINVAL;
> + port->operating_snk_mw = mw / 1000;
> + } else {
> + port->nr_snk_pdo = 0;
> + }
>
> port->self_powered = fwnode_property_read_bool(fwnode, "self-powered");
>
> - /* FRS can only be supported byb DRP ports */
> - if (port->port_type == TYPEC_PORT_DRP) {
> + /* FRS can only be supported by DRP ports */
> + if (port->port_type == TYPEC_PORT_DRP && port->pd_supported) {
> ret = fwnode_property_read_u32(fwnode, "new-source-frs-typec-current",
> &frs_current);
> if (ret >= 0 && frs_current <= FRS_5V_3A)
>


2021-07-28 02:12:52

by Kyle Tso

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] usb: typec: tcpm: Support non-PD mode

On Wed, Jul 28, 2021 at 6:46 AM Guenter Roeck <[email protected]> wrote:
>
> On 7/27/21 8:13 AM, Kyle Tso wrote:
> > Even if the Type-C controller supports PD, it is doable to disable PD
> > capabilities with the current state machine in TCPM. Without enabling RX
> > in low-level drivers and with skipping the power negotiation, the port
> > is eligible to be a non-PD Type-C port. Use new flags whose values are
> > populated from the device tree to decide the port PD capability. Adding
> > "pd-supported" property in device tree indicates that the port supports
> > PD. If "pd-supported" is not found, "typec-power-opmode" shall be added
> > to specify the advertised Rp value if the port supports SRC role.
> >
> > Signed-off-by: Kyle Tso <[email protected]>
> > ---
> > changes since v1:
> > - Revised the patch to use dt properties
> > - Added back the checks of callbacks set_pd_rx and pd_transmit
> > - Added src_rp to indicate which Rp value should be used in SRC. This
> > variable is derived from dt property "typec-power-opmode"
> >
> > drivers/usb/typec/tcpm/tcpm.c | 108 +++++++++++++++++++++++++---------
> > 1 file changed, 79 insertions(+), 29 deletions(-)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > index 5b22a1c931a9..4cf77c787f54 100644
> > --- a/drivers/usb/typec/tcpm/tcpm.c
> > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > @@ -316,6 +316,7 @@ struct tcpm_port {
> > struct typec_partner *partner;
> >
> > enum typec_cc_status cc_req;
> > + enum typec_cc_status src_rp; /* work only if pd_supported == false */
> >
> > enum typec_cc_status cc1;
> > enum typec_cc_status cc2;
> > @@ -323,6 +324,7 @@ struct tcpm_port {
> >
> > bool attached;
> > bool connected;
> > + bool pd_supported;
> > enum typec_port_type port_type;
> >
> > /*
> > @@ -804,6 +806,7 @@ static void tcpm_apply_rc(struct tcpm_port *port)
> > }
> > }
> >
> > +
> > /*
> > * Determine RP value to set based on maximum current supported
> > * by a port if configured as source.
> > @@ -815,6 +818,9 @@ static enum typec_cc_status tcpm_rp_cc(struct tcpm_port *port)
> > int nr_pdo = port->nr_src_pdo;
> > int i;
> >
> > + if (!port->pd_supported)
> > + return port->src_rp;
> > +
> > /*
> > * Search for first entry with matching voltage.
> > * It should report the maximum supported current.
> > @@ -3568,9 +3574,11 @@ static int tcpm_src_attach(struct tcpm_port *port)
> > if (ret < 0)
> > return ret;
> >
> > - ret = port->tcpc->set_pd_rx(port->tcpc, true);
> > - if (ret < 0)
> > - goto out_disable_mux;
> > + if (port->pd_supported) {
> > + ret = port->tcpc->set_pd_rx(port->tcpc, true);
> > + if (ret < 0)
> > + goto out_disable_mux;
> > + }
> >
> > /*
> > * USB Type-C specification, version 1.2,
> > @@ -3600,7 +3608,8 @@ static int tcpm_src_attach(struct tcpm_port *port)
> > out_disable_vconn:
> > tcpm_set_vconn(port, false);
> > out_disable_pd:
> > - port->tcpc->set_pd_rx(port->tcpc, false);
> > + if (port->pd_supported)
> > + port->tcpc->set_pd_rx(port->tcpc, false);
> > out_disable_mux:
> > tcpm_mux_set(port, TYPEC_STATE_SAFE, USB_ROLE_NONE,
> > TYPEC_ORIENTATION_NONE);
> > @@ -3804,6 +3813,20 @@ static enum typec_pwr_opmode tcpm_get_pwr_opmode(enum typec_cc_status cc)
> > }
> > }
> >
> > +static enum typec_cc_status tcpm_pwr_opmode_to_rp(enum typec_pwr_opmode opmode)
> > +{
> > + switch (opmode) {
> > + case TYPEC_PWR_MODE_USB:
> > + return TYPEC_CC_RP_DEF;
> > + case TYPEC_PWR_MODE_1_5A:
> > + return TYPEC_CC_RP_1_5;
> > + case TYPEC_PWR_MODE_3_0A:
> > + case TYPEC_PWR_MODE_PD:
> > + default:
> > + return TYPEC_CC_RP_3_0;
> > + }
> > +}
> > +
> > static void run_state_machine(struct tcpm_port *port)
> > {
> > int ret;
> > @@ -3914,6 +3937,10 @@ static void run_state_machine(struct tcpm_port *port)
> > if (port->ams == POWER_ROLE_SWAP ||
> > port->ams == FAST_ROLE_SWAP)
> > tcpm_ams_finish(port);
> > + if (!port->pd_supported) {
> > + tcpm_set_state(port, SRC_READY, 0);
> > + break;
> > + }
> > port->upcoming_state = SRC_SEND_CAPABILITIES;
> > tcpm_ams_start(port, POWER_NEGOTIATION);
> > break;
> > @@ -4161,7 +4188,10 @@ static void run_state_machine(struct tcpm_port *port)
> > current_lim = PD_P_SNK_STDBY_MW / 5;
> > tcpm_set_current_limit(port, current_lim, 5000);
> > tcpm_set_charge(port, true);
> > - tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
> > + if (!port->pd_supported)
> > + tcpm_set_state(port, SNK_READY, 0);
> > + else
> > + tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0);
> > break;
> > }
> > /*
> > @@ -4389,7 +4419,8 @@ static void run_state_machine(struct tcpm_port *port)
> > tcpm_set_vbus(port, true);
> > if (port->ams == HARD_RESET)
> > tcpm_ams_finish(port);
> > - port->tcpc->set_pd_rx(port->tcpc, true);
> > + if (port->pd_supported)
> > + port->tcpc->set_pd_rx(port->tcpc, true);
> > tcpm_set_attached_state(port, true);
> > tcpm_set_state(port, SRC_UNATTACHED, PD_T_PS_SOURCE_ON);
> > break;
> > @@ -5898,6 +5929,7 @@ EXPORT_SYMBOL_GPL(tcpm_tcpc_reset);
> > static int tcpm_fw_get_caps(struct tcpm_port *port,
> > struct fwnode_handle *fwnode)
> > {
> > + const char *opmode_str;
> > const char *cap_str;
> > int ret;
> > u32 mw, frs_current;
> > @@ -5932,22 +5964,36 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
> > return ret;
> > port->typec_caps.type = ret;
> > port->port_type = port->typec_caps.type;
> > + port->pd_supported = fwnode_property_read_bool(fwnode, "pd-supported");
> >
>
> As mentioned in the other patch, I think this needs to be negated.
> Not the variable itself, but the meaning of the property.
>

Makes sense. I will send another patch.

> > port->slow_charger_loop = fwnode_property_read_bool(fwnode, "slow-charger-loop");
>
> It might make sense to move the properties needed with !pd_supported to here
> and return immediately after they are read. This would reduce the number of
> required changes and avoid trying to read irrelevant properties.
> Something like
>
> if (port->port_type != TYPEC_PORT_SRC)
> port->self_powered = fwnode_property_read_bool(fwnode, "self-powered");
>
> if (!port->pd_supported)
> return 0;
>

I will try to modify the flow control as well.

thanks,
Kyle

> > if (port->port_type == TYPEC_PORT_SNK)
> > goto sink;
> >
> > /* Get source pdos */
> > - ret = fwnode_property_count_u32(fwnode, "source-pdos");
> > - if (ret <= 0)
> > - return -EINVAL;
> > + if (port->pd_supported) {
> > + ret = fwnode_property_count_u32(fwnode, "source-pdos");
> > + if (ret <= 0)
> > + return -EINVAL;
> >
> > - port->nr_src_pdo = min(ret, PDO_MAX_OBJECTS);
> > - ret = fwnode_property_read_u32_array(fwnode, "source-pdos",
> > - port->src_pdo, port->nr_src_pdo);
> > - if ((ret < 0) || tcpm_validate_caps(port, port->src_pdo,
> > - port->nr_src_pdo))
> > - return -EINVAL;
> > + port->nr_src_pdo = min(ret, PDO_MAX_OBJECTS);
> > + ret = fwnode_property_read_u32_array(fwnode, "source-pdos",
> > + port->src_pdo, port->nr_src_pdo);
> > + if ((ret < 0) || tcpm_validate_caps(port, port->src_pdo,
> > + port->nr_src_pdo))
> > + return -EINVAL;
> > + } else {
> > + port->nr_src_pdo = 0;
> > + ret = fwnode_property_read_string(fwnode, "typec-power-opmode", &opmode_str);
> > + if (ret == 0) {
> > + ret = typec_find_pwr_opmode(opmode_str);
> > + if (ret < 0)
> > + return ret;
> > + port->src_rp = tcpm_pwr_opmode_to_rp(ret);
> > + } else {
> > + return ret;
> > + }
> > + }
> >
> > if (port->port_type == TYPEC_PORT_SRC)
> > return 0;
> > @@ -5962,25 +6008,29 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
> > return -EINVAL;
> > sink:
> > /* Get sink pdos */
> > - ret = fwnode_property_count_u32(fwnode, "sink-pdos");
> > - if (ret <= 0)
> > - return -EINVAL;
> > + if (port->pd_supported) {
> > + ret = fwnode_property_count_u32(fwnode, "sink-pdos");
> > + if (ret <= 0)
> > + return -EINVAL;
> >
> > - port->nr_snk_pdo = min(ret, PDO_MAX_OBJECTS);
> > - ret = fwnode_property_read_u32_array(fwnode, "sink-pdos",
> > - port->snk_pdo, port->nr_snk_pdo);
> > - if ((ret < 0) || tcpm_validate_caps(port, port->snk_pdo,
> > - port->nr_snk_pdo))
> > - return -EINVAL;
> > + port->nr_snk_pdo = min(ret, PDO_MAX_OBJECTS);
> > + ret = fwnode_property_read_u32_array(fwnode, "sink-pdos",
> > + port->snk_pdo, port->nr_snk_pdo);
> > + if ((ret < 0) || tcpm_validate_caps(port, port->snk_pdo,
> > + port->nr_snk_pdo))
> > + return -EINVAL;
> >
> > - if (fwnode_property_read_u32(fwnode, "op-sink-microwatt", &mw) < 0)
> > - return -EINVAL;
> > - port->operating_snk_mw = mw / 1000;
> > + if (fwnode_property_read_u32(fwnode, "op-sink-microwatt", &mw) < 0)
> > + return -EINVAL;
> > + port->operating_snk_mw = mw / 1000;
> > + } else {
> > + port->nr_snk_pdo = 0;
> > + }
> >
> > port->self_powered = fwnode_property_read_bool(fwnode, "self-powered");
> >
> > - /* FRS can only be supported byb DRP ports */
> > - if (port->port_type == TYPEC_PORT_DRP) {
> > + /* FRS can only be supported by DRP ports */
> > + if (port->port_type == TYPEC_PORT_DRP && port->pd_supported) {
> > ret = fwnode_property_read_u32(fwnode, "new-source-frs-typec-current",
> > &frs_current);
> > if (ret >= 0 && frs_current <= FRS_5V_3A)
> >
>