xref: /openbmc/linux/sound/hda/hdac_bus.c (revision 3471b9f7)
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 	return 0;
50 }
51 EXPORT_SYMBOL_GPL(snd_hdac_bus_init);
52 
53 /**
54  * snd_hdac_bus_exit - clean up a HD-audio bas bus
55  * @bus: the pointer to bus object
56  */
57 void snd_hdac_bus_exit(struct hdac_bus *bus)
58 {
59 	WARN_ON(!list_empty(&bus->stream_list));
60 	WARN_ON(!list_empty(&bus->codec_list));
61 	cancel_work_sync(&bus->unsol_work);
62 }
63 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit);
64 
65 /**
66  * snd_hdac_bus_exec_verb - execute a HD-audio verb on the given bus
67  * @bus: bus object
68  * @addr: the HDAC device address
69  * @cmd: HD-audio encoded verb
70  * @res: pointer to store the response, NULL if performing asynchronously
71  *
72  * Returns 0 if successful, or a negative error code.
73  */
74 int snd_hdac_bus_exec_verb(struct hdac_bus *bus, unsigned int addr,
75 			   unsigned int cmd, unsigned int *res)
76 {
77 	int err;
78 
79 	mutex_lock(&bus->cmd_mutex);
80 	err = snd_hdac_bus_exec_verb_unlocked(bus, addr, cmd, res);
81 	mutex_unlock(&bus->cmd_mutex);
82 	return err;
83 }
84 
85 /**
86  * snd_hdac_bus_exec_verb_unlocked - unlocked version
87  * @bus: bus object
88  * @addr: the HDAC device address
89  * @cmd: HD-audio encoded verb
90  * @res: pointer to store the response, NULL if performing asynchronously
91  *
92  * Returns 0 if successful, or a negative error code.
93  */
94 int snd_hdac_bus_exec_verb_unlocked(struct hdac_bus *bus, unsigned int addr,
95 				    unsigned int cmd, unsigned int *res)
96 {
97 	unsigned int tmp;
98 	int err;
99 
100 	if (cmd == ~0)
101 		return -EINVAL;
102 
103 	if (res)
104 		*res = -1;
105 	else if (bus->sync_write)
106 		res = &tmp;
107 	for (;;) {
108 		trace_hda_send_cmd(bus, cmd);
109 		err = bus->ops->command(bus, cmd);
110 		if (err != -EAGAIN)
111 			break;
112 		/* process pending verbs */
113 		err = bus->ops->get_response(bus, addr, &tmp);
114 		if (err)
115 			break;
116 	}
117 	if (!err && res) {
118 		err = bus->ops->get_response(bus, addr, res);
119 		trace_hda_get_response(bus, addr, *res);
120 	}
121 	return err;
122 }
123 EXPORT_SYMBOL_GPL(snd_hdac_bus_exec_verb_unlocked);
124 
125 /**
126  * snd_hdac_bus_queue_event - add an unsolicited event to queue
127  * @bus: the BUS
128  * @res: unsolicited event (lower 32bit of RIRB entry)
129  * @res_ex: codec addr and flags (upper 32bit or RIRB entry)
130  *
131  * Adds the given event to the queue.  The events are processed in
132  * the workqueue asynchronously.  Call this function in the interrupt
133  * hanlder when RIRB receives an unsolicited event.
134  */
135 void snd_hdac_bus_queue_event(struct hdac_bus *bus, u32 res, u32 res_ex)
136 {
137 	unsigned int wp;
138 
139 	if (!bus)
140 		return;
141 
142 	trace_hda_unsol_event(bus, res, res_ex);
143 	wp = (bus->unsol_wp + 1) % HDA_UNSOL_QUEUE_SIZE;
144 	bus->unsol_wp = wp;
145 
146 	wp <<= 1;
147 	bus->unsol_queue[wp] = res;
148 	bus->unsol_queue[wp + 1] = res_ex;
149 
150 	schedule_work(&bus->unsol_work);
151 }
152 
153 /*
154  * process queued unsolicited events
155  */
156 static void snd_hdac_bus_process_unsol_events(struct work_struct *work)
157 {
158 	struct hdac_bus *bus = container_of(work, struct hdac_bus, unsol_work);
159 	struct hdac_device *codec;
160 	struct hdac_driver *drv;
161 	unsigned int rp, caddr, res;
162 
163 	spin_lock_irq(&bus->reg_lock);
164 	while (bus->unsol_rp != bus->unsol_wp) {
165 		rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE;
166 		bus->unsol_rp = rp;
167 		rp <<= 1;
168 		res = bus->unsol_queue[rp];
169 		caddr = bus->unsol_queue[rp + 1];
170 		if (!(caddr & (1 << 4))) /* no unsolicited event? */
171 			continue;
172 		codec = bus->caddr_tbl[caddr & 0x0f];
173 		if (!codec || !codec->dev.driver)
174 			continue;
175 		spin_unlock_irq(&bus->reg_lock);
176 		drv = drv_to_hdac_driver(codec->dev.driver);
177 		if (drv->unsol_event)
178 			drv->unsol_event(codec, res);
179 		spin_lock_irq(&bus->reg_lock);
180 	}
181 	spin_unlock_irq(&bus->reg_lock);
182 }
183 
184 /**
185  * snd_hdac_bus_add_device - Add a codec to bus
186  * @bus: HDA core bus
187  * @codec: HDA core device to add
188  *
189  * Adds the given codec to the list in the bus.  The caddr_tbl array
190  * and codec_powered bits are updated, as well.
191  * Returns zero if success, or a negative error code.
192  */
193 int snd_hdac_bus_add_device(struct hdac_bus *bus, struct hdac_device *codec)
194 {
195 	if (bus->caddr_tbl[codec->addr]) {
196 		dev_err(bus->dev, "address 0x%x is already occupied\n",
197 			codec->addr);
198 		return -EBUSY;
199 	}
200 
201 	list_add_tail(&codec->list, &bus->codec_list);
202 	bus->caddr_tbl[codec->addr] = codec;
203 	set_bit(codec->addr, &bus->codec_powered);
204 	bus->num_codecs++;
205 	return 0;
206 }
207 
208 /**
209  * snd_hdac_bus_remove_device - Remove a codec from bus
210  * @bus: HDA core bus
211  * @codec: HDA core device to remove
212  */
213 void snd_hdac_bus_remove_device(struct hdac_bus *bus,
214 				struct hdac_device *codec)
215 {
216 	WARN_ON(bus != codec->bus);
217 	if (list_empty(&codec->list))
218 		return;
219 	list_del_init(&codec->list);
220 	bus->caddr_tbl[codec->addr] = NULL;
221 	clear_bit(codec->addr, &bus->codec_powered);
222 	bus->num_codecs--;
223 	flush_work(&bus->unsol_work);
224 }
225 
226 #ifdef CONFIG_SND_HDA_ALIGNED_MMIO
227 /* Helpers for aligned read/write of mmio space, for Tegra */
228 unsigned int snd_hdac_aligned_read(void __iomem *addr, unsigned int mask)
229 {
230 	void __iomem *aligned_addr =
231 		(void __iomem *)((unsigned long)(addr) & ~0x3);
232 	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
233 	unsigned int v;
234 
235 	v = readl(aligned_addr);
236 	return (v >> shift) & mask;
237 }
238 EXPORT_SYMBOL_GPL(snd_hdac_aligned_read);
239 
240 void snd_hdac_aligned_write(unsigned int val, void __iomem *addr,
241 			    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 	v &= ~(mask << shift);
250 	v |= val << shift;
251 	writel(v, aligned_addr);
252 }
253 EXPORT_SYMBOL_GPL(snd_hdac_aligned_write);
254 #endif /* CONFIG_SND_HDA_ALIGNED_MMIO */
255