sound/usb/power.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *   UAC3 Power Domain state management functions
0004  */
0005
0006 #include <linux/slab.h>
0007 #include <linux/usb.h>
0008 #include <linux/usb/audio.h>
0009 #include <linux/usb/audio-v2.h>
0010 #include <linux/usb/audio-v3.h>
0011
0012 #include "usbaudio.h"
0013 #include "helper.h"
0014 #include "power.h"
0015
0016 struct snd_usb_power_domain *
0017 snd_usb_find_power_domain(struct usb_host_interface *ctrl_iface,
0018               unsigned char id)
0019 {
0020     struct snd_usb_power_domain *pd;
0021     void *p;
0022
0023     pd = kzalloc(sizeof(*pd), GFP_KERNEL);
0024     if (!pd)
0025         return NULL;
0026
0027     p = NULL;
0028     while ((p = snd_usb_find_csint_desc(ctrl_iface->extra,
0029                         ctrl_iface->extralen,
0030                         p, UAC3_POWER_DOMAIN)) != NULL) {
0031         struct uac3_power_domain_descriptor *pd_desc = p;
0032         int i;
0033
0034         if (!snd_usb_validate_audio_desc(p, UAC_VERSION_3))
0035             continue;
0036         for (i = 0; i < pd_desc->bNrEntities; i++) {
0037             if (pd_desc->baEntityID[i] == id) {
0038                 pd->pd_id = pd_desc->bPowerDomainID;
0039                 pd->pd_d1d0_rec =
0040                     le16_to_cpu(pd_desc->waRecoveryTime1);
0041                 pd->pd_d2d0_rec =
0042                     le16_to_cpu(pd_desc->waRecoveryTime2);
0043                 return pd;
0044             }
0045         }
0046     }
0047
0048     kfree(pd);
0049     return NULL;
0050 }
0051
0052 int snd_usb_power_domain_set(struct snd_usb_audio *chip,
0053                  struct snd_usb_power_domain *pd,
0054                  unsigned char state)
0055 {
0056     struct usb_device *dev = chip->dev;
0057     unsigned char current_state;
0058     int err, idx;
0059
0060     idx = snd_usb_ctrl_intf(chip) | (pd->pd_id << 8);
0061
0062     err = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0),
0063                   UAC2_CS_CUR,
0064                   USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
0065                   UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
0066                   &current_state, sizeof(current_state));
0067     if (err < 0) {
0068         dev_err(&dev->dev, "Can't get UAC3 power state for id %d\n",
0069             pd->pd_id);
0070         return err;
0071     }
0072
0073     if (current_state == state) {
0074         dev_dbg(&dev->dev, "UAC3 power domain id %d already in state %d\n",
0075             pd->pd_id, state);
0076         return 0;
0077     }
0078
0079     err = snd_usb_ctl_msg(chip->dev, usb_sndctrlpipe(chip->dev, 0), UAC2_CS_CUR,
0080                   USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
0081                   UAC3_AC_POWER_DOMAIN_CONTROL << 8, idx,
0082                   &state, sizeof(state));
0083     if (err < 0) {
0084         dev_err(&dev->dev, "Can't set UAC3 power state to %d for id %d\n",
0085             state, pd->pd_id);
0086         return err;
0087     }
0088
0089     if (state == UAC3_PD_STATE_D0) {
0090         switch (current_state) {
0091         case UAC3_PD_STATE_D2:
0092             udelay(pd->pd_d2d0_rec * 50);
0093             break;
0094         case UAC3_PD_STATE_D1:
0095             udelay(pd->pd_d1d0_rec * 50);
0096             break;
0097         default:
0098             return -EINVAL;
0099         }
0100     }
0101
0102     dev_dbg(&dev->dev, "UAC3 power domain id %d change to state %d\n",
0103         pd->pd_id, state);
0104
0105     return 0;
0106 }