bus.c

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