xref: /openbmc/linux/sound/hda/hdac_bus.c (revision 6abeae2a)
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 };
21 
22 /**
23  * snd_hdac_bus_init - initialize a HD-audio bas bus
24  * @bus: the pointer to bus object
25  * @dev: device pointer
26  * @ops: bus verb operators
27  *
28  * Returns 0 if successful, or a negative error code.
29  */
30 int snd_hdac_bus_init(struct hdac_bus *bus, struct device *dev,
31 		      const struct hdac_bus_ops *ops)
32 {
33 	memset(bus, 0, sizeof(*bus));
34 	bus->dev = dev;
35 	if (ops)
36 		bus->ops = ops;
37 	else
38 		bus->ops = &default_ops;
39 	bus->dma_type = SNDRV_DMA_TYPE_DEV;
40 	INIT_LIST_HEAD(&bus->stream_list);
41 	INIT_LIST_HEAD(&bus->codec_list);
42 	INIT_WORK(&bus->unsol_work, snd_hdac_bus_process_unsol_events);
43 	spin_lock_init(&bus->reg_lock);
44 	mutex_init(&bus->cmd_mutex);
45 	mutex_init(&bus->lock);
46 	INIT_LIST_HEAD(&bus->hlink_list);
47 	init_waitqueue_head(&bus->rirb_wq);
48 	bus->irq = -1;
49 
50 	/*
51 	 * Default value of '8' is as per the HD audio specification (Rev 1.0a).
52 	 * Following relation is used to derive STRIPE control value.
53 	 *  For sample rate <= 48K:
54 	 *   { ((num_channels * bits_per_sample) / number of SDOs) >= 8 }
55 	 *  For sample rate > 48K:
56 	 *   { ((num_channels * bits_per_sample * rate/48000) /
57 	 *	number of SDOs) >= 8 }
58 	 */
59 	bus->sdo_limit = 8;
60 
61 	return 0;
62 }
63 EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
64 
65 /**
66  * snd_hdac_bus_exit - clean up a HD-audio bas bus
67  * @bus: the pointer to bus object
68  */
69 void snd_hdac_bus_exit(struct hdac_bus *bus)
70 {
71 	WARN_ON(!list_empty(&bus->stream_list));
72 	WARN_ON(!list_empty(&bus->codec_list));
73 	cancel_work_sync(&bus->unsol_work);
74 }
75 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
76 
77 /**
78  * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
79  * @bus: bus object
80  * @addr: the HDAC device address
81  * @cmd: HD-audio encoded verb
82  * @res: pointer to store the response, NULL if performing asynchronously
83  *
84  * Returns 0 if successful, or a negative error code.
85  */
86 int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
87 			   unsigned int cmd, unsigned int *res)
88 {
89 	int err;
90 
91 	mutex_lock(&bus->cmd_mutex);
92 	err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
93 	mutex_unlock(&bus->cmd_mutex);
94 	return err;
95 }
96 
97 /**
98  * snd_hdac_bus_exec_verb_unlocked - unlocked version
99  * @bus: bus object
100  * @addr: the HDAC device address
101  * @cmd: HD-audio encoded verb
102  * @res: pointer to store the response, NULL if performing asynchronously
103  *
104  * Returns 0 if successful, or a negative error code.
105  */
106 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
107 				    unsigned int cmd, unsigned int *res)
108 {
109 	unsigned int tmp;
110 	int err;
111 
112 	if (cmd == ~0)
113 		return -EINVAL;
114 
115 	if (res)
116 		*res = -1;
117 	else if (bus->sync_write)
118 		res = &tmp;
119 	for (;;) {
120 		trace_hda_send_cmd(bus, cmd);
121 		err = bus->ops->command(bus, cmd);
122 		if (err != -EAGAIN)
123 			break;
124 		/* process pending verbs */
125 		err = bus->ops->get_response(bus, addr, &tmp);
126 		if (err)
127 			break;
128 	}
129 	if (!err && res) {
130 		err = bus->ops->get_response(bus, addr, res);
131 		trace_hda_get_response(bus, addr, *res);
132 	}
133 	return err;
134 }
135 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
136 
137 /**
138  * snd_hdac_bus_queue_event - add an unsolicited event to queue
139  * @bus: the BUS
140  * @res: unsolicited event (lower 32bit of RIRB entry)
141  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
142  *
143  * Adds the given event to the queue.  The events are processed in
144  * the workqueue asynchronously.  Call this function in the interrupt
145  * hanlder when RIRB receives an unsolicited event.
146  */
147 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
148 {
149 	unsigned int wp;
150 
151 	if (!bus)
152 		return;
153 
154 	trace_hda_unsol_event(bus, res, res_ex);
155 	wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
156 	bus->unsol_wp = wp;
157 
158 	wp <<= 1;
159 	bus->unsol_queue[wp] = res;
160 	bus->unsol_queue[wp + 1] = res_ex;
161 
162 	schedule_work(&bus->unsol_work);
163 }
164 
165 /*
166  * process queued unsolicited events
167  */
168 static void snd_hdac_bus_process_unsol_events(struct work_struct *work)
169 {
170 	struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
171 	struct hdac_device *codec;
172 	struct hdac_driver *drv;
173 	unsigned int rp, caddr, res;
174 
175 	spin_lock_irq(&bus->reg_lock);
176 	while (bus->unsol_rp != bus->unsol_wp) {
177 		rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
178 		bus->unsol_rp = rp;
179 		rp <<= 1;
180 		res = bus->unsol_queue[rp];
181 		caddr = bus->unsol_queue[rp + 1];
182 		if (!(caddr & (1 << 4))) /* no unsolicited event? */
183 			continue;
184 		codec = bus->caddr_tbl[caddr & 0x0f];
185 		if (!codec || !codec->dev.driver)
186 			continue;
187 		spin_unlock_irq(&bus->reg_lock);
188 		drv = drv_to_hdac_driver(codec->dev.driver);
189 		if (drv->unsol_event)
190 			drv->unsol_event(codec, res);
191 		spin_lock_irq(&bus->reg_lock);
192 	}
193 	spin_unlock_irq(&bus->reg_lock);
194 }
195 
196 /**
197  * snd_hdac_bus_add_device - Add a codec to bus
198  * @bus: HDA core bus
199  * @codec: HDA core device to add
200  *
201  * Adds the given codec to the list in the bus.  The caddr_tbl array
202  * and codec_powered bits are updated, as well.
203  * Returns zero if success, or a negative error code.
204  */
205 int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
206 {
207 	if (bus->caddr_tbl[codec->addr]) {
208 		dev_err(bus->dev, "address 0x%x is already occupied\n",
209 			codec->addr);
210 		return -EBUSY;
211 	}
212 
213 	list_add_tail(&codec->list, &bus->codec_list);
214 	bus->caddr_tbl[codec->addr] = codec;
215 	set_bit(codec->addr, &bus->codec_powered);
216 	bus->num_codecs++;
217 	return 0;
218 }
219 
220 /**
221  * snd_hdac_bus_remove_device - Remove a codec from bus
222  * @bus: HDA core bus
223  * @codec: HDA core device to remove
224  */
225 void snd_hdac_bus_remove_device(struct hdac_bus *bus,
226 				struct hdac_device *codec)
227 {
228 	WARN_ON(bus != codec->bus);
229 	if (list_empty(&codec->list))
230 		return;
231 	list_del_init(&codec->list);
232 	bus->caddr_tbl[codec->addr] = NULL;
233 	clear_bit(codec->addr, &bus->codec_powered);
234 	bus->num_codecs--;
235 	flush_work(&bus->unsol_work);
236 }
237 
238 #ifdef CONFIG_SND_HDA_ALIGNED_MMIO
239 /* Helpers for aligned read/write of mmio space, for Tegra */
240 unsigned int snd_hdac_aligned_read(void __iomem *addr, unsigned int mask)
241 {
242 	void __iomem *aligned_addr =
243 		(void __iomem *)((unsigned long)(addr) & ~0x3);
244 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
245 	unsigned int v;
246 
247 	v = readl(aligned_addr);
248 	return (v >> shift) & mask;
249 }
250 EXPORT_SYMBOL_GPL(snd_hdac_aligned_read);
251 
252 void snd_hdac_aligned_write(unsigned int val, void __iomem *addr,
253 			    unsigned int mask)
254 {
255 	void __iomem *aligned_addr =
256 		(void __iomem *)((unsigned long)(addr) & ~0x3);
257 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
258 	unsigned int v;
259 
260 	v = readl(aligned_addr);
261 	v &= ~(mask << shift);
262 	v |= val << shift;
263 	writel(v, aligned_addr);
264 }
265 EXPORT_SYMBOL_GPL(snd_hdac_aligned_write);
266 #endif /* CONFIG_SND_HDA_ALIGNED_MMIO */
267