xref: /linux/sound/hda/core/bus.c (revision 05a54fa773284d1a7923cdfdd8f0c8dabb98bd26)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * HD-audio core bus driver
4  */
5 
6 #include <linux/init.h>
7 #include <linux/io.h>
8 #include <linux/device.h>
9 #include <linux/module.h>
10 #include <linux/export.h>
11 #include <sound/hdaudio.h>
12 #include "local.h"
13 #include "trace.h"
14 
15 static void snd_hdac_bus_process_unsol_events(struct work_struct *work);
16 
17 static const struct hdac_bus_ops default_ops = {
18 	.command = snd_hdac_bus_send_cmd,
19 	.get_response = snd_hdac_bus_get_response,
20 	.link_power = snd_hdac_bus_link_power,
21 };
22 
23 /**
24  * snd_hdac_bus_init - initialize a HD-audio bas bus
25  * @bus: the pointer to bus object
26  * @dev: device pointer
27  * @ops: bus verb operators
28  *
29  * Returns 0 if successful, or a negative error code.
30  */
31 int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
32 		      const struct hdac_bus_ops *ops)
33 {
34 	memset(bus, 0, sizeof(*bus));
35 	bus->dev = dev;
36 	if (ops)
37 		bus->ops = ops;
38 	else
39 		bus->ops = &default_ops;
40 	bus->dma_type = SNDRV_DMA_TYPE_DEV;
41 	INIT_LIST_HEAD(&bus->stream_list);
42 	INIT_LIST_HEAD(&bus->codec_list);
43 	INIT_WORK(&bus->unsol_work, snd_hdac_bus_process_unsol_events);
44 	spin_lock_init(&bus->reg_lock);
45 	mutex_init(&bus->cmd_mutex);
46 	mutex_init(&bus->lock);
47 	INIT_LIST_HEAD(&bus->hlink_list);
48 	init_waitqueue_head(&bus->rirb_wq);
49 	bus->irq = -1;
50 
51 	/*
52 	 * Default value of '8' is as per the HD audio specification (Rev 1.0a).
53 	 * Following relation is used to derive STRIPE control value.
54 	 *  For sample rate <= 48K:
55 	 *   { ((num_channels * bits_per_sample) / number of SDOs) >= 8 }
56 	 *  For sample rate > 48K:
57 	 *   { ((num_channels * bits_per_sample * rate/48000) /
58 	 *	number of SDOs) >= 8 }
59 	 */
60 	bus->sdo_limit = 8;
61 
62 	return 0;
63 }
64 EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
65 
66 /**
67  * snd_hdac_bus_exit - clean up a HD-audio bas bus
68  * @bus: the pointer to bus object
69  */
70 void snd_hdac_bus_exit(struct hdac_bus *bus)
71 {
72 	WARN_ON(!list_empty(&bus->stream_list));
73 	WARN_ON(!list_empty(&bus->codec_list));
74 	cancel_work_sync(&bus->unsol_work);
75 }
76 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
77 
78 /**
79  * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
80  * @bus: bus object
81  * @addr: the HDAC device address
82  * @cmd: HD-audio encoded verb
83  * @res: pointer to store the response, NULL if performing asynchronously
84  *
85  * Returns 0 if successful, or a negative error code.
86  */
87 int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
88 			   unsigned int cmd, unsigned int *res)
89 {
90 	guard(mutex)(&bus->cmd_mutex);
91 	return snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
92 }
93 
94 /**
95  * snd_hdac_bus_exec_verb_unlocked - unlocked version
96  * @bus: bus object
97  * @addr: the HDAC device address
98  * @cmd: HD-audio encoded verb
99  * @res: pointer to store the response, NULL if performing asynchronously
100  *
101  * Returns 0 if successful, or a negative error code.
102  */
103 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
104 				    unsigned int cmd, unsigned int *res)
105 {
106 	unsigned int tmp;
107 	int err;
108 
109 	if (cmd == ~0)
110 		return -EINVAL;
111 
112 	if (res)
113 		*res = -1;
114 	else if (bus->sync_write)
115 		res = &tmp;
116 	for (;;) {
117 		trace_hda_send_cmd(bus, cmd);
118 		err = bus->ops->command(bus, cmd);
119 		if (err != -EAGAIN)
120 			break;
121 		/* process pending verbs */
122 		err = bus->ops->get_response(bus, addr, &tmp);
123 		if (err)
124 			break;
125 	}
126 	if (!err && res) {
127 		err = bus->ops->get_response(bus, addr, res);
128 		trace_hda_get_response(bus, addr, *res);
129 	}
130 	return err;
131 }
132 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
133 
134 /**
135  * snd_hdac_bus_queue_event - add an unsolicited event to queue
136  * @bus: the BUS
137  * @res: unsolicited event (lower 32bit of RIRB entry)
138  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
139  *
140  * Adds the given event to the queue.  The events are processed in
141  * the workqueue asynchronously.  Call this function in the interrupt
142  * hanlder when RIRB receives an unsolicited event.
143  */
144 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
145 {
146 	unsigned int wp;
147 
148 	if (!bus)
149 		return;
150 
151 	trace_hda_unsol_event(bus, res, res_ex);
152 	wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
153 	bus->unsol_wp = wp;
154 
155 	wp <<= 1;
156 	bus->unsol_queue[wp] = res;
157 	bus->unsol_queue[wp + 1] = res_ex;
158 
159 	schedule_work(&bus->unsol_work);
160 }
161 
162 /*
163  * process queued unsolicited events
164  */
165 static void snd_hdac_bus_process_unsol_events(struct work_struct *work)
166 {
167 	struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
168 	struct hdac_device *codec;
169 	struct hdac_driver *drv;
170 	unsigned int rp, caddr, res;
171 
172 	spin_lock_irq(&bus->reg_lock);
173 	while (bus->unsol_rp != bus->unsol_wp) {
174 		rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
175 		bus->unsol_rp = rp;
176 		rp <<= 1;
177 		res = bus->unsol_queue[rp];
178 		caddr = bus->unsol_queue[rp + 1];
179 		if (!(caddr & (1 << 4))) /* no unsolicited event? */
180 			continue;
181 		codec = bus->caddr_tbl[caddr & 0x0f];
182 		if (!codec || !codec->registered)
183 			continue;
184 		spin_unlock_irq(&bus->reg_lock);
185 		drv = drv_to_hdac_driver(codec->dev.driver);
186 		if (drv->unsol_event)
187 			drv->unsol_event(codec, res);
188 		spin_lock_irq(&bus->reg_lock);
189 	}
190 	spin_unlock_irq(&bus->reg_lock);
191 }
192 
193 /**
194  * snd_hdac_bus_add_device - Add a codec to bus
195  * @bus: HDA core bus
196  * @codec: HDA core device to add
197  *
198  * Adds the given codec to the list in the bus.  The caddr_tbl array
199  * and codec_powered bits are updated, as well.
200  * Returns zero if success, or a negative error code.
201  */
202 int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
203 {
204 	if (bus->caddr_tbl[codec->addr]) {
205 		dev_err(bus->dev, "address 0x%x is already occupied\n",
206 			codec->addr);
207 		return -EBUSY;
208 	}
209 
210 	list_add_tail(&codec->list, &bus->codec_list);
211 	bus->caddr_tbl[codec->addr] = codec;
212 	set_bit(codec->addr, &bus->codec_powered);
213 	bus->num_codecs++;
214 	return 0;
215 }
216 
217 /**
218  * snd_hdac_bus_remove_device - Remove a codec from bus
219  * @bus: HDA core bus
220  * @codec: HDA core device to remove
221  */
222 void snd_hdac_bus_remove_device(struct hdac_bus *bus,
223 				struct hdac_device *codec)
224 {
225 	WARN_ON(bus != codec->bus);
226 	if (list_empty(&codec->list))
227 		return;
228 	list_del_init(&codec->list);
229 	bus->caddr_tbl[codec->addr] = NULL;
230 	clear_bit(codec->addr, &bus->codec_powered);
231 	bus->num_codecs--;
232 	flush_work(&bus->unsol_work);
233 }
234 
235 #ifdef CONFIG_SND_HDA_ALIGNED_MMIO
236 /* Helpers for aligned read/write of mmio space, for Tegra */
237 unsigned int snd_hdac_aligned_read(void __iomem *addr, unsigned int mask)
238 {
239 	void __iomem *aligned_addr =
240 		(void __iomem *)((unsigned long)(addr) & ~0x3);
241 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
242 	unsigned int v;
243 
244 	v = readl(aligned_addr);
245 	return (v >> shift) & mask;
246 }
247 EXPORT_SYMBOL_GPL(snd_hdac_aligned_read);
248 
249 void snd_hdac_aligned_write(unsigned int val, void __iomem *addr,
250 			    unsigned int mask)
251 {
252 	void __iomem *aligned_addr =
253 		(void __iomem *)((unsigned long)(addr) & ~0x3);
254 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
255 	unsigned int v;
256 
257 	v = readl(aligned_addr);
258 	v &= ~(mask << shift);
259 	v |= val << shift;
260 	writel(v, aligned_addr);
261 }
262 EXPORT_SYMBOL_GPL(snd_hdac_aligned_write);
263 #endif /* CONFIG_SND_HDA_ALIGNED_MMIO */
264 
265 void snd_hdac_codec_link_up(struct hdac_device *codec)
266 {
267 	struct hdac_bus *bus = codec->bus;
268 
269 	if (bus->ops->link_power)
270 		bus->ops->link_power(codec, true);
271 	else
272 		snd_hdac_bus_link_power(codec, true);
273 }
274 EXPORT_SYMBOL_GPL(snd_hdac_codec_link_up);
275 
276 void snd_hdac_codec_link_down(struct hdac_device *codec)
277 {
278 	struct hdac_bus *bus = codec->bus;
279 
280 	if (bus->ops->link_power)
281 		bus->ops->link_power(codec, false);
282 	else
283 		snd_hdac_bus_link_power(codec, false);
284 }
285 EXPORT_SYMBOL_GPL(snd_hdac_codec_link_down);
286