usb: gadget: function: f_uac1: implement get_alt()

After commit 7e4da3fcf7c9 ("usb: gadget: composite:
Test get_alt() presence instead of set_alt()") f_uac1
function became broken because it doesn't have
get_alt() callback implementation and composite
framework never set altsetting 1 for audiostreaming
interface. On host site it looks like:

 [424339.017711] 21:1:1: usb_set_interface failed (-32)

Since host can't set altsetting 1, it can't start
playing audio.

In order to fix it implemented get_alt along with
minor improvements (error conditions checking)
similar to what existing f_uac2 has.

Cc: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/gadget/function/f_uac1.c b/drivers/usb/gadget/function/f_uac1.c
index f2ac0cb..5dfc94b 100644 (file)
--- a/drivers/usb/gadget/function/f_uac1.c
+++ b/drivers/usb/gadget/function/f_uac1.c
@@ -277,6 +277,9 @@ static void f_audio_buffer_free(struct f_audio_buf *audio_buf)
 struct f_audio {
        struct gaudio                   card;
 
+       u8 ac_intf, ac_alt;
+       u8 as_intf, as_alt;
+
        /* endpoints handle full and/or high speeds */
        struct usb_ep                   *out_ep;
 
@@ -586,7 +589,20 @@ static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
        req_count = opts->req_count;
        audio_buf_size = opts->audio_buf_size;
 
-       if (intf == 1) {
+       /* No i/f has more than 2 alt settings */
+       if (alt > 1) {
+               ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
+               return -EINVAL;
+       }
+
+       if (intf == audio->ac_intf) {
+               /* Control I/f has only 1 AltSetting - 0 */
+               if (alt) {
+                       ERROR(cdev, "%s:%d Error!\n", __func__, __LINE__);
+                       return -EINVAL;
+               }
+               return 0;
+       } else if (intf == audio->as_intf) {
                if (alt == 1) {
                        err = config_ep_by_speed(cdev->gadget, f, out_ep);
                        if (err)
@@ -631,11 +647,28 @@ static int f_audio_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
                                schedule_work(&audio->playback_work);
                        }
                }
+               audio->as_alt = alt;
        }
 
        return err;
 }
 
+static int f_audio_get_alt(struct usb_function *f, unsigned intf)
+{
+       struct f_audio          *audio = func_to_audio(f);
+       struct usb_composite_dev *cdev = f->config->cdev;
+
+       if (intf == audio->ac_intf)
+               return audio->ac_alt;
+       else if (intf == audio->as_intf)
+               return audio->as_alt;
+       else
+               ERROR(cdev, "%s:%d Invalid Interface %d!\n",
+                     __func__, __LINE__, intf);
+
+       return -EINVAL;
+}
+
 static void f_audio_disable(struct usb_function *f)
 {
        return;
@@ -702,12 +735,16 @@ f_audio_bind(struct usb_configuration *c, struct usb_function *f)
        if (status < 0)
                goto fail;
        ac_interface_desc.bInterfaceNumber = status;
+       audio->ac_intf = status;
+       audio->ac_alt = 0;
 
        status = usb_interface_id(c, f);
        if (status < 0)
                goto fail;
        as_interface_alt_0_desc.bInterfaceNumber = status;
        as_interface_alt_1_desc.bInterfaceNumber = status;
+       audio->as_intf = status;
+       audio->as_alt = 0;
 
        status = -ENODEV;
 
@@ -966,6 +1003,7 @@ static struct usb_function *f_audio_alloc(struct usb_function_instance *fi)
        audio->card.func.bind = f_audio_bind;
        audio->card.func.unbind = f_audio_unbind;
        audio->card.func.set_alt = f_audio_set_alt;
+       audio->card.func.get_alt = f_audio_get_alt;
        audio->card.func.setup = f_audio_setup;
        audio->card.func.disable = f_audio_disable;
        audio->card.func.free_func = f_audio_free;