Hi,

On 06-08-17 16:18, Guenter Roeck wrote:
On 08/06/2017 05:35 AM, Hans de Goede wrote:
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
for USB2 power-sources (through e.g. BC1.2 detection).

This commit adds an optional get_usb2_current_limit tcpc_dev callback
which allows the port-controller to return the detected current-limit
if the CC pin is pulled up with Rp.

Signed-off-by: Hans de Goede <hdego...@redhat.com>
---
  drivers/staging/typec/tcpm.c | 5 ++++-
  drivers/staging/typec/tcpm.h | 1 +
  2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index 20eb4ebcf8c3..9f5adace4309 100644
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -660,7 +660,10 @@ static u32 tcpm_get_current_limit(struct tcpm_port *port)
          break;
      case TYPEC_CC_RP_DEF:
      default:
-        limit = 0;
+        if (port->tcpc->get_usb2_current_limit)

I think this callback should just be get_current_limit.

This is only used in the Rp-def case, which usually indicates being connected
with an A->C cable to a USB-2 device and the intend is for the callback to
implement some USB-2 specific method to detect the supported current-limit,
hence the name. If you prefer to name it just get_current_limit I can
change it for v2, but IMHO the usb2 part of the name is important as this
will not get called when USB-PD negotiation is used, nor when Rp has the Rp15
or Rp30 values.

Regards,

Hans




+            limit = port->tcpc->get_usb2_current_limit(port->tcpc);
+        else
+            limit = 0;
          break;
      }
diff --git a/drivers/staging/typec/tcpm.h b/drivers/staging/typec/tcpm.h
index 19c307d31a5a..01b7d89379a3 100644
--- a/drivers/staging/typec/tcpm.h
+++ b/drivers/staging/typec/tcpm.h
@@ -108,6 +108,7 @@ struct tcpc_dev {
      int (*init)(struct tcpc_dev *dev);
      int (*get_vbus)(struct tcpc_dev *dev);
+    int (*get_usb2_current_limit)(struct tcpc_dev *dev); /* Optional */
      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);


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