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                 for (i = 0; i < pd_desc->bNrEntities; i++) {
  35                         if (pd_desc->baEntityID[i] == id) {
  36                                 pd->pd_id = pd_desc->bPowerDomainID;
  37                                 pd->pd_d1d0_rec =
  38                                         le16_to_cpu(pd_desc->waRecoveryTime1);
  39                                 pd->pd_d2d0_rec =
  40                                         le16_to_cpu(pd_desc->waRecoveryTime2);
  41                                 return pd;
  42                         }
  43                 }
  44         }
  45
  46         kfree(pd);
  47         return NULL;
  48 }
  49
  50 int snd_usb_power_domain_set(struct snd_usb_audio *chip,
  51                              struct snd_usb_power_domain *pd,
  52                              unsigned char state)
  53 {
  54         struct usb_device *dev = chip->dev;
  55         unsigned char current_state;
  56         int err, idx;
  57
  58         idx = snd_usb_ctrl_intf(chip) | (pd->pd_id << 8);
  59
  60         err = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
  61                               UAC2_CS_CUR,
  62                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
  63                               UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
  64                               &current_state, sizeof(current_state));
  65         if (err < 0) {
  66                 dev_err(&dev->dev, "Can't get UAC3 power state for id %d\n",
  67                         pd->pd_id);
  68                 return err;
  69         }
  70
  71         if (current_state == state) {
  72                 dev_dbg(&dev->dev, "UAC3 power domain id %d already in state %d\n",
  73                         pd->pd_id, state);
  74                 return 0;
  75         }
  76
  77         err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
  78                               USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
  79                               UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
  80                               &state, sizeof(state));
  81         if (err < 0) {
  82                 dev_err(&dev->dev, "Can't set UAC3 power state to %d for id %d\n",
  83                         state, pd->pd_id);
  84                 return err;
  85         }
  86
  87         if (state == UAC3_PD_STATE_D0) {
  88                 switch (current_state) {
  89                 case UAC3_PD_STATE_D2:
  90                         udelay(pd->pd_d2d0_rec * 50);
  91                         break;
  92                 case UAC3_PD_STATE_D1:
  93                         udelay(pd->pd_d1d0_rec * 50);
  94                         break;
  95                 default:
  96                         return -EINVAL;
  97                 }
  98         }
  99
 100         dev_dbg(&dev->dev, "UAC3 power domain id %d change to state %d\n",
 101                 pd->pd_id, state);
 102
 103         return 0;
 104 }