xref: /openbmc/linux/sound/hda/hdac_bus.c (revision e40573a4)
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 	int err;
91 
92 	mutex_lock(&bus->cmd_mutex);
93 	err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
94 	mutex_unlock(&bus->cmd_mutex);
95 	return err;
96 }
97 
98 /**
99  * snd_hdac_bus_exec_verb_unlocked - unlocked version
100  * @bus: bus object
101  * @addr: the HDAC device address
102  * @cmd: HD-audio encoded verb
103  * @res: pointer to store the response, NULL if performing asynchronously
104  *
105  * Returns 0 if successful, or a negative error code.
106  */
107 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
108 				    unsigned int cmd, unsigned int *res)
109 {
110 	unsigned int tmp;
111 	int err;
112 
113 	if (cmd == ~0)
114 		return -EINVAL;
115 
116 	if (res)
117 		*res = -1;
118 	else if (bus->sync_write)
119 		res = &tmp;
120 	for (;;) {
121 		trace_hda_send_cmd(bus, cmd);
122 		err = bus->ops->command(bus, cmd);
123 		if (err != -EAGAIN)
124 			break;
125 		/* process pending verbs */
126 		err = bus->ops->get_response(bus, addr, &tmp);
127 		if (err)
128 			break;
129 	}
130 	if (!err && res) {
131 		err = bus->ops->get_response(bus, addr, res);
132 		trace_hda_get_response(bus, addr, *res);
133 	}
134 	return err;
135 }
136 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
137 
138 /**
139  * snd_hdac_bus_queue_event - add an unsolicited event to queue
140  * @bus: the BUS
141  * @res: unsolicited event (lower 32bit of RIRB entry)
142  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
143  *
144  * Adds the given event to the queue.  The events are processed in
145  * the workqueue asynchronously.  Call this function in the interrupt
146  * hanlder when RIRB receives an unsolicited event.
147  */
148 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
149 {
150 	unsigned int wp;
151 
152 	if (!bus)
153 		return;
154 
155 	trace_hda_unsol_event(bus, res, res_ex);
156 	wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
157 	bus->unsol_wp = wp;
158 
159 	wp <<= 1;
160 	bus->unsol_queue[wp] = res;
161 	bus->unsol_queue[wp + 1] = res_ex;
162 
163 	schedule_work(&bus->unsol_work);
164 }
165 
166 /*
167  * process queued unsolicited events
168  */
169 static void snd_hdac_bus_process_unsol_events(struct work_struct *work)
170 {
171 	struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
172 	struct hdac_device *codec;
173 	struct hdac_driver *drv;
174 	unsigned int rp, caddr, res;
175 
176 	spin_lock_irq(&bus->reg_lock);
177 	while (bus->unsol_rp != bus->unsol_wp) {
178 		rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
179 		bus->unsol_rp = rp;
180 		rp <<= 1;
181 		res = bus->unsol_queue[rp];
182 		caddr = bus->unsol_queue[rp + 1];
183 		if (!(caddr & (1 << 4))) /* no unsolicited event? */
184 			continue;
185 		codec = bus->caddr_tbl[caddr & 0x0f];
186 		if (!codec || !codec->registered)
187 			continue;
188 		spin_unlock_irq(&bus->reg_lock);
189 		drv = drv_to_hdac_driver(codec->dev.driver);
190 		if (drv->unsol_event)
191 			drv->unsol_event(codec, res);
192 		spin_lock_irq(&bus->reg_lock);
193 	}
194 	spin_unlock_irq(&bus->reg_lock);
195 }
196 
197 /**
198  * snd_hdac_bus_add_device - Add a codec to bus
199  * @bus: HDA core bus
200  * @codec: HDA core device to add
201  *
202  * Adds the given codec to the list in the bus.  The caddr_tbl array
203  * and codec_powered bits are updated, as well.
204  * Returns zero if success, or a negative error code.
205  */
206 int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
207 {
208 	if (bus->caddr_tbl[codec->addr]) {
209 		dev_err(bus->dev, "address 0x%x is already occupied\n",
210 			codec->addr);
211 		return -EBUSY;
212 	}
213 
214 	list_add_tail(&codec->list, &bus->codec_list);
215 	bus->caddr_tbl[codec->addr] = codec;
216 	set_bit(codec->addr, &bus->codec_powered);
217 	bus->num_codecs++;
218 	return 0;
219 }
220 
221 /**
222  * snd_hdac_bus_remove_device - Remove a codec from bus
223  * @bus: HDA core bus
224  * @codec: HDA core device to remove
225  */
226 void snd_hdac_bus_remove_device(struct hdac_bus *bus,
227 				struct hdac_device *codec)
228 {
229 	WARN_ON(bus != codec->bus);
230 	if (list_empty(&codec->list))
231 		return;
232 	list_del_init(&codec->list);
233 	bus->caddr_tbl[codec->addr] = NULL;
234 	clear_bit(codec->addr, &bus->codec_powered);
235 	bus->num_codecs--;
236 	flush_work(&bus->unsol_work);
237 }
238 
239 #ifdef CONFIG_SND_HDA_ALIGNED_MMIO
240 /* Helpers for aligned read/write of mmio space, for Tegra */
241 unsigned int snd_hdac_aligned_read(void __iomem *addr, unsigned int mask)
242 {
243 	void __iomem *aligned_addr =
244 		(void __iomem *)((unsigned long)(addr) & ~0x3);
245 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
246 	unsigned int v;
247 
248 	v = readl(aligned_addr);
249 	return (v >> shift) & mask;
250 }
251 EXPORT_SYMBOL_GPL(snd_hdac_aligned_read);
252 
253 void snd_hdac_aligned_write(unsigned int val, void __iomem *addr,
254 			    unsigned int mask)
255 {
256 	void __iomem *aligned_addr =
257 		(void __iomem *)((unsigned long)(addr) & ~0x3);
258 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
259 	unsigned int v;
260 
261 	v = readl(aligned_addr);
262 	v &= ~(mask << shift);
263 	v |= val << shift;
264 	writel(v, aligned_addr);
265 }
266 EXPORT_SYMBOL_GPL(snd_hdac_aligned_write);
267 #endif /* CONFIG_SND_HDA_ALIGNED_MMIO */
268 
269 void snd_hdac_codec_link_up(struct hdac_device *codec)
270 {
271 	struct hdac_bus *bus = codec->bus;
272 
273 	if (bus->ops->link_power)
274 		bus->ops->link_power(codec, true);
275 	else
276 		snd_hdac_bus_link_power(codec, true);
277 }
278 EXPORT_SYMBOL_GPL(snd_hdac_codec_link_up);
279 
280 void snd_hdac_codec_link_down(struct hdac_device *codec)
281 {
282 	struct hdac_bus *bus = codec->bus;
283 
284 	if (bus->ops->link_power)
285 		bus->ops->link_power(codec, false);
286 	else
287 		snd_hdac_bus_link_power(codec, false);
288 }
289 EXPORT_SYMBOL_GPL(snd_hdac_codec_link_down);
290