Re: [PATCH 2/3] usb: chipidea: Hook into mux framework to toggle usb switch

Quoting Peter Rosin (2017-07-11 23:45:24)

On 2017-07-12 03:02, Stephen Boyd wrote:

quoted

@@ -102,4 +107,7 @@ Example:
              rx-burst-size-dword = <0x10>;
              extcon = <0>, <&usb_id>;
              phy-clkgate-delay-us = <400>;
+             mux-controls = <&usb_switch>;
+             mux-control-names = "usb_switch";
+             usb-switch-states = <0>, <1>;

I don't see the need for usb-switch-states? Just assume states 0/1 and
if someone later needs some other states, make them add a property that
overrides the defaults. Just document that 0 is host and 1 is device.

Fine by me. Rob H do you agree?

quoted

diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index 18cb8e46262d..9fd23ecc2da3 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c

@@ -25,6 +25,7 @@
 #include <linux/usb/hcd.h>
 #include <linux/usb/chipidea.h>
 #include <linux/regulator/consumer.h>
+#include <linux/mux/consumer.h>
 
 #include "../host/ehci.h"
 

@@ -123,6 +124,13 @@ static int host_start(struct ci_hdrc *ci)
      if (usb_disabled())
              return -ENODEV;
 
+     if (!IS_ERR(ci->platdata->usb_switch.mux)) {
+             ret = mux_control_select(ci->platdata->usb_switch.mux,
+                                      ci->platdata->usb_switch.host);
+             if (ret)
+                     return ret;
+     }
+

You *must* call mux_control_deselect to clean up if there is a failure
later in host_start. Is that handled in some non-obvious way?

Good catch. Thanks. I'll add in the unwinding on the error path.