On 08/06/2017 07:36 AM, Hans de Goede wrote:

On 06-08-17 16:22, Guenter Roeck wrote:
On 08/06/2017 05:35 AM, Hans de Goede wrote:
The fusb302 port-controller relies on an external device doing USB2
charger-type detection.

The Intel Whiskey Cove PMIC with which the fusb302 is combined on some
X86/ACPI platforms already has a charger-type detection driver which
uses extcon to communicate the detected charger-type.

This commit uses the tcpm_get_usb2_current_limit_extcon helper to enable
USB2 charger detection on these systems. Note that the "fcs,extcon-name"
property name is only for kernel internal use by X86/ACPI platform code
and as such is NOT documented in the devicetree bindings.

Signed-off-by: Hans de Goede <hdego...@redhat.com>
  drivers/staging/typec/fusb302/fusb302.c | 16 ++++++++++++++++
  1 file changed, 16 insertions(+)

diff --git a/drivers/staging/typec/fusb302/fusb302.c 
index be454b5ff6c7..1d8c9b66df2f 100644
--- a/drivers/staging/typec/fusb302/fusb302.c
+++ b/drivers/staging/typec/fusb302/fusb302.c
@@ -1201,6 +1201,8 @@ static void init_tcpc_dev(struct tcpc_dev 
      fusb302_tcpc_dev->init = tcpm_init;
      fusb302_tcpc_dev->get_vbus = tcpm_get_vbus;
+    fusb302_tcpc_dev->get_usb2_current_limit =
+        tcpm_get_usb2_current_limit_extcon;
      fusb302_tcpc_dev->set_cc = tcpm_set_cc;
      fusb302_tcpc_dev->get_cc = tcpm_get_cc;
      fusb302_tcpc_dev->set_polarity = tcpm_set_polarity;
@@ -1685,6 +1687,7 @@ static int fusb302_probe(struct i2c_client *client,
      struct fusb302_chip *chip;
      struct i2c_adapter *adapter;
      struct device *dev = &client->dev;
+    const char *name;
      int ret = 0;
      u32 val;
@@ -1717,6 +1720,19 @@ static int fusb302_probe(struct i2c_client *client,
      if (device_property_read_u32(dev, "fcs,operating-snk-mw", &val) == 0)
          chip->tcpc_config.operating_snk_mw = val;
+    /*
+     * Devicetree platforms should get extcon via phandle (not yet
+     * supported). On ACPI platforms, we get the name from a device prop.
+     * This device prop is for kernel internal use only and is expected
+     * to be set by the platform code which also registers the i2c client
+     * for the fusb302.
+     */
+    if (device_property_read_string(dev, "fcs,extcon-name", &name) == 0) {

Those new devicetree properties need to be documented and approved by dt 

As indicated by the comment, this property should not be used in the devicetree
case, notice this is a device-property and not an of property and since it is
not intended to be used with devicetree at all (in devicetree a phandle rather
then a name would be used), it has no place under Documentation/devicetree at 

Ok. I thought device properties were supposed to unify dt and non-dt situations,
but apparently not. Oh well :-(.

Also there is no current binding documentation for the "fcs,fusb302" compatible
and the weird "fcs,int_n" gpio which really is an irq which it already uses.

Yes, one of those TODO items for moving the code out of staging. "fcs," should
possibly be "fusb302,", and int_n _is_ weird.

+        chip->tcpc_dev.usb2_extcon = extcon_get_extcon_dev(name);
+        if (!chip->tcpc_dev.usb2_extcon)

extcon_get_extcon_dev() can also return an ERR_PTR.

As before, I am not really happy typing this into tcpm via tcpc_dev.
Until we have a better solution, I would prefer for that code to stay with the 

Ok, I tried to make this all re-usable since I think other port-controller 
will need something similar, but I can kill the entire tcpm-helpers.c file in v2
and then put everything in fusb302.c. I take it that that is what you want ?

Yes, please.

Also, please copy Yueyao Zhu for the fusb302 changes in v2.


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