staging: typec: tcpm: Add get_current_limit tcpc_dev callback

A Rp signalling the default current limit indicates that we're possibly
connected to an USB2 power-source. In some cases the type-c port-controller
may provide the capability to detect the current-limit in this case,
through e.g. BC1.2 detection.

This commit adds an optional get_current_limit tcpc_dev callback which
allows the port-controller to provide current-limit detection for when
the CC pin is pulled up with Rp.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index 2ce02aba039ae16ca3acaab5cc76ad538ab6f6d1..8af62e74d54c6319678f315a48e302a761dbb71c 100644 (file)
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -685,7 +685,10 @@ static u32 tcpm_get_current_limit(struct tcpm_port *port)
                break;
        case TYPEC_CC_RP_DEF:
        default:
-               limit = 0;
+               if (port->tcpc->get_current_limit)
+                       limit = port->tcpc->get_current_limit(port->tcpc);
+               else
+                       limit = 0;
                break;
        }
 

diff --git a/drivers/staging/typec/tcpm.h b/drivers/staging/typec/tcpm.h
index 374cea44a84a778f15c4b7e45c061807a0d5a0d4..7e9a6b7b5cd6be4bb8e7b253c119a509b464929e 100644 (file)
--- a/drivers/staging/typec/tcpm.h
+++ b/drivers/staging/typec/tcpm.h
@@ -109,6 +109,13 @@ struct tcpc_dev {
 
        int (*init)(struct tcpc_dev *dev);
        int (*get_vbus)(struct tcpc_dev *dev);
+       /*
+        * This optional callback gets called by the tcpm core when configured
+        * as a snk and cc=Rp-def. This allows the tcpm to provide a fallback
+        * current-limit detection method for the cc=Rp-def case. E.g. some
+        * tcpcs may include BC1.2 charger detection and use that in this case.
+        */
+       int (*get_current_limit)(struct tcpc_dev *dev);
        int (*set_cc)(struct tcpc_dev *dev, enum typec_cc_status cc);
        int (*get_cc)(struct tcpc_dev *dev, enum typec_cc_status *cc1,
                      enum typec_cc_status *cc2);