root/sound/usb/power.c

DEFINITIONS

1. snd_usb_find_power_domain
2. snd_usb_power_domain_set

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *   UAC3 Power Domain state management functions
   4  */
   5 
   6 #include <linux/slab.h>
   7 #include <linux/usb.h>
   8 #include <linux/usb/audio.h>
   9 #include <linux/usb/audio-v2.h>
  10 #include <linux/usb/audio-v3.h>
  11 
  12 #include "usbaudio.h"
  13 #include "helper.h"
  14 #include "power.h"
  15 
  16 struct snd_usb_power_domain *
  17 snd_usb_find_power_domain(struct usb_host_interface *ctrl_iface,
  18                           unsigned char id)
  19 {
  20         struct snd_usb_power_domain *pd;
  21         void *p;
  22 
  23         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
  24         if (!pd)
  25                 return NULL;
  26 
  27         p = NULL;
  28         while ((p = snd_usb_find_csint_desc(ctrl_iface->extra,
  29                                             ctrl_iface->extralen,
  30                                             p, UAC3_POWER_DOMAIN)) != NULL) {
  31                 struct uac3_power_domain_descriptor *pd_desc = p;
  32                 int i;
  33 
  34                 if (!snd_usb_validate_audio_desc(p, UAC_VERSION_3))
  35                         continue;
  36                 for (i = 0; i < pd_desc->bNrEntities; i++) {
  37                         if (pd_desc->baEntityID[i] == id) {
  38                                 pd->pd_id = pd_desc->bPowerDomainID;
  39                                 pd->pd_d1d0_rec =
  40                                         le16_to_cpu(pd_desc->waRecoveryTime1);
  41                                 pd->pd_d2d0_rec =
  42                                         le16_to_cpu(pd_desc->waRecoveryTime2);
  43                                 return pd;
  44                         }
  45                 }
  46         }
  47 
  48         kfree(pd);
  49         return NULL;
  50 }
  51 
  52 int snd_usb_power_domain_set(struct snd_usb_audio *chip,
  53                              struct snd_usb_power_domain *pd,
  54                              unsigned char state)
  55 {
  56         struct usb_device *dev = chip->dev;
  57         unsigned char current_state;
  58         int err, idx;
  59 
  60         idx = snd_usb_ctrl_intf(chip) | (pd->pd_id << 8);
  61 
  62         err = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
  63                               UAC2_CS_CUR,
  64                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
  65                               UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
  66                               &current_state, sizeof(current_state));
  67         if (err < 0) {
  68                 dev_err(&dev->dev, "Can't get UAC3 power state for id %d\n",
  69                         pd->pd_id);
  70                 return err;
  71         }
  72 
  73         if (current_state == state) {
  74                 dev_dbg(&dev->dev, "UAC3 power domain id %d already in state %d\n",
  75                         pd->pd_id, state);
  76                 return 0;
  77         }
  78 
  79         err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
  80                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
  81                               UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
  82                               &state, sizeof(state));
  83         if (err < 0) {
  84                 dev_err(&dev->dev, "Can't set UAC3 power state to %d for id %d\n",
  85                         state, pd->pd_id);
  86                 return err;
  87         }
  88 
  89         if (state == UAC3_PD_STATE_D0) {
  90                 switch (current_state) {
  91                 case UAC3_PD_STATE_D2:
  92                         udelay(pd->pd_d2d0_rec * 50);
  93                         break;
  94                 case UAC3_PD_STATE_D1:
  95                         udelay(pd->pd_d1d0_rec * 50);
  96                         break;
  97                 default:
  98                         return -EINVAL;
  99                 }
 100         }
 101 
 102         dev_dbg(&dev->dev, "UAC3 power domain id %d change to state %d\n",
 103                 pd->pd_id, state);
 104 
 105         return 0;
 106 }