sound/usb/power.c

   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                                 pd->ctrl_iface = ctrl_iface;
  44                                 return pd;
  45                         }
  46                 }
  47         }
  48
  49         kfree(pd);
  50         return NULL;
  51 }
  52
  53 int snd_usb_power_domain_set(struct snd_usb_audio *chip,
  54                              struct snd_usb_power_domain *pd,
  55                              unsigned char state)
  56 {
  57         struct usb_device *dev = chip->dev;
  58         unsigned char current_state;
  59         int err, idx;
  60
  61         idx = snd_usb_ctrl_intf(pd->ctrl_iface) | (pd->pd_id << 8);
  62
  63         err = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
  64                               UAC2_CS_CUR,
  65                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
  66                               UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
  67                               &current_state, sizeof(current_state));
  68         if (err < 0) {
  69                 dev_err(&dev->dev, "Can't get UAC3 power state for id %d\n",
  70                         pd->pd_id);
  71                 return err;
  72         }
  73
  74         if (current_state == state) {
  75                 dev_dbg(&dev->dev, "UAC3 power domain id %d already in state %d\n",
  76                         pd->pd_id, state);
  77                 return 0;
  78         }
  79
  80         err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
  81                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
  82                               UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
  83                               &state, sizeof(state));
  84         if (err < 0) {
  85                 dev_err(&dev->dev, "Can't set UAC3 power state to %d for id %d\n",
  86                         state, pd->pd_id);
  87                 return err;
  88         }
  89
  90         if (state == UAC3_PD_STATE_D0) {
  91                 switch (current_state) {
  92                 case UAC3_PD_STATE_D2:
  93                         udelay(pd->pd_d2d0_rec * 50);
  94                         break;
  95                 case UAC3_PD_STATE_D1:
  96                         udelay(pd->pd_d1d0_rec * 50);
  97                         break;
  98                 default:
  99                         return -EINVAL;
 100                 }
 101         }
 102
 103         dev_dbg(&dev->dev, "UAC3 power domain id %d change to state %d\n",
 104                 pd->pd_id, state);
 105
 106         return 0;
 107 }