Quelle  power.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 *   UAC3 Power Domain state management functions
 */

#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/audio.h>
#include <linux/usb/audio-v2.h>
#include <linux/usb/audio-v3.h>

#include "usbaudio.h"
#include "helper.h"
#include "power.h"

struct snd_usb_power_domain *
snd_usb_find_power_domain(struct usb_host_interface *ctrl_iface,
     unsigned char id)
{
 struct snd_usb_power_domain *pd;
 void *p;

 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 if (!pd)
  return NULL;

 p = NULL;
 while ((p = snd_usb_find_csint_desc(ctrl_iface->extra,
         ctrl_iface->extralen,
         p, UAC3_POWER_DOMAIN)) != NULL) {
  struct uac3_power_domain_descriptor *pd_desc = p;
  int i;

  if (!snd_usb_validate_audio_desc(p, UAC_VERSION_3))
   continue;
  for (i = 0; i < pd_desc->bNrEntities; i++) {
   if (pd_desc->baEntityID[i] == id) {
    pd->pd_id = pd_desc->bPowerDomainID;
    pd->pd_d1d0_rec =
     le16_to_cpu(pd_desc->waRecoveryTime1);
    pd->pd_d2d0_rec =
     le16_to_cpu(pd_desc->waRecoveryTime2);
    pd->ctrl_iface = ctrl_iface;
    return pd;
   }
  }
 }

 kfree(pd);
 return NULL;
}

int snd_usb_power_domain_set(struct snd_usb_audio *chip,
        struct snd_usb_power_domain *pd,
        unsigned char state)
{
 struct usb_device *dev = chip->dev;
 unsigned char current_state;
 int err, idx;

 idx = snd_usb_ctrl_intf(pd->ctrl_iface) | (pd->pd_id << 8);

 err = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
         UAC2_CS_CUR,
         USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
         UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
         ¤t_state, sizeof(current_state));
 if (err < 0) {
  dev_err(&dev->dev, "Can't get UAC3 power state for id %d\n",
   pd->pd_id);
  return err;
 }

 if (current_state == state) {
  dev_dbg(&dev->dev, "UAC3 power domain id %d already in state %d\n",
   pd->pd_id, state);
  return 0;
 }

 err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
         USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
         UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
         &state, sizeof(state));
 if (err < 0) {
  dev_err(&dev->dev, "Can't set UAC3 power state to %d for id %d\n",
   state, pd->pd_id);
  return err;
 }

 if (state == UAC3_PD_STATE_D0) {
  switch (current_state) {
  case UAC3_PD_STATE_D2:
   udelay(pd->pd_d2d0_rec * 50);
   break;
  case UAC3_PD_STATE_D1:
   udelay(pd->pd_d1d0_rec * 50);
   break;
  default:
   return -EINVAL;
  }
 }

 dev_dbg(&dev->dev, "UAC3 power domain id %d change to state %d\n",
  pd->pd_id, state);

 return 0;
}