Re: [PATCH v3 2/2] usb: typec: tcpm: Support non-PD mode
From: Guenter Roeck <linux@roeck-us.net>
Date: 2021-07-28 14:31:38
Also in:
linux-devicetree, lkml
On 7/28/21 2:29 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-unsupported" property in device tree indicates that the port does not support PD. If "pd-unsupported" is not found, "typec-power-opmode"
"is not found" -> "is found" (based on previous revision) I think "If PD is not supported, ..." might be a better wording and avoid the use of a property name here.
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shall be added to specify the advertised Rp value if the port supports SRC role. Signed-off-by: Kyle Tso <redacted> --- changes since v2: - Changed the control flow if the port is SNK or DRP. Return directly if the flag is false (PD not supported). Read "self-powered" before that. drivers/usb/typec/tcpm/tcpm.c | 88 ++++++++++++++++++++++++++++------- 1 file changed, 70 insertions(+), 18 deletions(-)diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 5b22a1c931a9..d8d6ef8c6282 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) } } +
stray empty line
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/* * 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 +5964,37 @@ 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-unsupported"); port->slow_charger_loop = fwnode_property_read_bool(fwnode, "slow-charger-loop"); +
Unnecessary whitespace change
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))Since we are changing this code, might as well get rid of the unnecessary () around 'ret < 0'. Or, even better, if (ret) return ret; ret = tcpm_validate_caps(port, port->src_pdo, port->nr_src_pdo); if (ret) return ret; because that avoids overwriting the error return code from fwnode_property_read_u32_array().
+ return -EINVAL;
+ } else {
+ port->nr_src_pdo = 0;That should be unnecessary.
+ 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;
+ }I prefer 'normal' error handling. if (ret) return ret; ret = typec_find_pwr_opmode(opmode_str); ...
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+ } if (port->port_type == TYPEC_PORT_SRC) return 0;@@ -5961,6 +6008,13 @@ static int tcpm_fw_get_caps(struct tcpm_port *port, if (port->typec_caps.prefer_role < 0) return -EINVAL; sink: + port->self_powered = fwnode_property_read_bool(fwnode, "self-powered"); + + if (!port->pd_supported) { + port->nr_snk_pdo = 0;
Should be unnecessary.
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+ return 0; + } + /* Get sink pdos */ ret = fwnode_property_count_u32(fwnode, "sink-pdos"); if (ret <= 0)@@ -5977,9 +6031,7 @@ static int tcpm_fw_get_caps(struct tcpm_port *port, return -EINVAL; port->operating_snk_mw = mw / 1000; - port->self_powered = fwnode_property_read_bool(fwnode, "self-powered"); - - /* FRS can only be supported byb DRP ports */ + /* FRS can only be supported by DRP ports */ if (port->port_type == TYPEC_PORT_DRP) { ret = fwnode_property_read_u32(fwnode, "new-source-frs-typec-current", &frs_current);