xref: /openbmc/linux/sound/usb/power.c (revision fe0a5788)
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 }
107