usb: typec: ucsi: psy: Set current max to 100mA for BC 1.2 and Default

ucsi_psy_get_current_max would return 0mA as the maximum current if
UCSI detected a BC or a Default USB Power sporce.

The comment in this function is true that we can't tell the difference
between DCP/CDP or SDP chargers, but we can guarantee that at least 1-unit
of USB 1.1/2.0 power is available, which is 100mA, which is a better
fallback value than 0, which causes some userspaces, including the ChromeOS
power manager, to regard this as a power source that is not providing
any power.

In reality, 100mA is guaranteed from all sources in these classes.

Signed-off-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Jameson Thies <jthies@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20250717200805.3710473-1-bleung@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/ucsi/psy.c b/drivers/usb/typec/ucsi/psy.c
index 62ac69730405029498107904dddef9741d923225..62a9d68bb66d21bc805035c29db9b30936d5c802 100644 (file)
--- a/drivers/usb/typec/ucsi/psy.c
+++ b/drivers/usb/typec/ucsi/psy.c
@@ -164,7 +164,7 @@ static int ucsi_psy_get_current_max(struct ucsi_connector *con,
        case UCSI_CONSTAT_PWR_OPMODE_DEFAULT:
        /* UCSI can't tell b/w DCP/CDP or USB2/3x1/3x2 SDP chargers */
        default:
-               val->intval = 0;
+               val->intval = UCSI_TYPEC_DEFAULT_CURRENT * 1000;
                break;
        }
        return 0;

diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index b711e1ecc3785eeb34e407e58df939f2d29bdb38..ebd7c27c2cc766d5e3778baa91e85d2dbffa789f 100644 (file)
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -483,9 +483,10 @@ struct ucsi {
 #define UCSI_MAX_SVID          5
 #define UCSI_MAX_ALTMODES      (UCSI_MAX_SVID * 6)
 
-#define UCSI_TYPEC_VSAFE5V     5000
-#define UCSI_TYPEC_1_5_CURRENT 1500
-#define UCSI_TYPEC_3_0_CURRENT 3000
+#define UCSI_TYPEC_VSAFE5V             5000
+#define UCSI_TYPEC_DEFAULT_CURRENT      100
+#define UCSI_TYPEC_1_5_CURRENT         1500
+#define UCSI_TYPEC_3_0_CURRENT         3000
 
 struct ucsi_connector {
        int num;