xref: /openbmc/linux/sound/drivers/pcsp/pcsp_lib.c (revision 588b48ca)
1 /*
2  * PC-Speaker driver for Linux
3  *
4  * Copyright (C) 1993-1997  Michael Beck
5  * Copyright (C) 1997-2001  David Woodhouse
6  * Copyright (C) 2001-2008  Stas Sergeev
7  */
8 
9 #include <linux/module.h>
10 #include <linux/gfp.h>
11 #include <linux/moduleparam.h>
12 #include <linux/interrupt.h>
13 #include <sound/pcm.h>
14 #include <asm/io.h>
15 #include "pcsp.h"
16 
17 static bool nforce_wa;
18 module_param(nforce_wa, bool, 0444);
19 MODULE_PARM_DESC(nforce_wa, "Apply NForce chipset workaround "
20 		"(expect bad sound)");
21 
22 #define DMIX_WANTS_S16	1
23 
24 /*
25  * Call snd_pcm_period_elapsed in a tasklet
26  * This avoids spinlock messes and long-running irq contexts
27  */
28 static void pcsp_call_pcm_elapsed(unsigned long priv)
29 {
30 	if (atomic_read(&pcsp_chip.timer_active)) {
31 		struct snd_pcm_substream *substream;
32 		substream = pcsp_chip.playback_substream;
33 		if (substream)
34 			snd_pcm_period_elapsed(substream);
35 	}
36 }
37 
38 static DECLARE_TASKLET(pcsp_pcm_tasklet, pcsp_call_pcm_elapsed, 0);
39 
40 /* write the port and returns the next expire time in ns;
41  * called at the trigger-start and in hrtimer callback
42  */
43 static u64 pcsp_timer_update(struct snd_pcsp *chip)
44 {
45 	unsigned char timer_cnt, val;
46 	u64 ns;
47 	struct snd_pcm_substream *substream;
48 	struct snd_pcm_runtime *runtime;
49 	unsigned long flags;
50 
51 	if (chip->thalf) {
52 		outb(chip->val61, 0x61);
53 		chip->thalf = 0;
54 		return chip->ns_rem;
55 	}
56 
57 	substream = chip->playback_substream;
58 	if (!substream)
59 		return 0;
60 
61 	runtime = substream->runtime;
62 	/* assume it is mono! */
63 	val = runtime->dma_area[chip->playback_ptr + chip->fmt_size - 1];
64 	if (chip->is_signed)
65 		val ^= 0x80;
66 	timer_cnt = val * CUR_DIV() / 256;
67 
68 	if (timer_cnt && chip->enable) {
69 		raw_spin_lock_irqsave(&i8253_lock, flags);
70 		if (!nforce_wa) {
71 			outb_p(chip->val61, 0x61);
72 			outb_p(timer_cnt, 0x42);
73 			outb(chip->val61 ^ 1, 0x61);
74 		} else {
75 			outb(chip->val61 ^ 2, 0x61);
76 			chip->thalf = 1;
77 		}
78 		raw_spin_unlock_irqrestore(&i8253_lock, flags);
79 	}
80 
81 	chip->ns_rem = PCSP_PERIOD_NS();
82 	ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem);
83 	chip->ns_rem -= ns;
84 	return ns;
85 }
86 
87 static void pcsp_pointer_update(struct snd_pcsp *chip)
88 {
89 	struct snd_pcm_substream *substream;
90 	size_t period_bytes, buffer_bytes;
91 	int periods_elapsed;
92 	unsigned long flags;
93 
94 	/* update the playback position */
95 	substream = chip->playback_substream;
96 	if (!substream)
97 		return;
98 
99 	period_bytes = snd_pcm_lib_period_bytes(substream);
100 	buffer_bytes = snd_pcm_lib_buffer_bytes(substream);
101 
102 	spin_lock_irqsave(&chip->substream_lock, flags);
103 	chip->playback_ptr += PCSP_INDEX_INC() * chip->fmt_size;
104 	periods_elapsed = chip->playback_ptr - chip->period_ptr;
105 	if (periods_elapsed < 0) {
106 #if PCSP_DEBUG
107 		printk(KERN_INFO "PCSP: buffer_bytes mod period_bytes != 0 ? "
108 			"(%zi %zi %zi)\n",
109 			chip->playback_ptr, period_bytes, buffer_bytes);
110 #endif
111 		periods_elapsed += buffer_bytes;
112 	}
113 	periods_elapsed /= period_bytes;
114 	/* wrap the pointer _before_ calling snd_pcm_period_elapsed(),
115 	 * or ALSA will BUG on us. */
116 	chip->playback_ptr %= buffer_bytes;
117 
118 	if (periods_elapsed) {
119 		chip->period_ptr += periods_elapsed * period_bytes;
120 		chip->period_ptr %= buffer_bytes;
121 	}
122 	spin_unlock_irqrestore(&chip->substream_lock, flags);
123 
124 	if (periods_elapsed)
125 		tasklet_schedule(&pcsp_pcm_tasklet);
126 }
127 
128 enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)
129 {
130 	struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer);
131 	int pointer_update;
132 	u64 ns;
133 
134 	if (!atomic_read(&chip->timer_active) || !chip->playback_substream)
135 		return HRTIMER_NORESTART;
136 
137 	pointer_update = !chip->thalf;
138 	ns = pcsp_timer_update(chip);
139 	if (!ns) {
140 		printk(KERN_WARNING "PCSP: unexpected stop\n");
141 		return HRTIMER_NORESTART;
142 	}
143 
144 	if (pointer_update)
145 		pcsp_pointer_update(chip);
146 
147 	hrtimer_forward(handle, hrtimer_get_expires(handle), ns_to_ktime(ns));
148 
149 	return HRTIMER_RESTART;
150 }
151 
152 static int pcsp_start_playing(struct snd_pcsp *chip)
153 {
154 #if PCSP_DEBUG
155 	printk(KERN_INFO "PCSP: start_playing called\n");
156 #endif
157 	if (atomic_read(&chip->timer_active)) {
158 		printk(KERN_ERR "PCSP: Timer already active\n");
159 		return -EIO;
160 	}
161 
162 	raw_spin_lock(&i8253_lock);
163 	chip->val61 = inb(0x61) | 0x03;
164 	outb_p(0x92, 0x43);	/* binary, mode 1, LSB only, ch 2 */
165 	raw_spin_unlock(&i8253_lock);
166 	atomic_set(&chip->timer_active, 1);
167 	chip->thalf = 0;
168 
169 	hrtimer_start(&pcsp_chip.timer, ktime_set(0, 0), HRTIMER_MODE_REL);
170 	return 0;
171 }
172 
173 static void pcsp_stop_playing(struct snd_pcsp *chip)
174 {
175 #if PCSP_DEBUG
176 	printk(KERN_INFO "PCSP: stop_playing called\n");
177 #endif
178 	if (!atomic_read(&chip->timer_active))
179 		return;
180 
181 	atomic_set(&chip->timer_active, 0);
182 	raw_spin_lock(&i8253_lock);
183 	/* restore the timer */
184 	outb_p(0xb6, 0x43);	/* binary, mode 3, LSB/MSB, ch 2 */
185 	outb(chip->val61 & 0xFC, 0x61);
186 	raw_spin_unlock(&i8253_lock);
187 }
188 
189 /*
190  * Force to stop and sync the stream
191  */
192 void pcsp_sync_stop(struct snd_pcsp *chip)
193 {
194 	local_irq_disable();
195 	pcsp_stop_playing(chip);
196 	local_irq_enable();
197 	hrtimer_cancel(&chip->timer);
198 	tasklet_kill(&pcsp_pcm_tasklet);
199 }
200 
201 static int snd_pcsp_playback_close(struct snd_pcm_substream *substream)
202 {
203 	struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
204 #if PCSP_DEBUG
205 	printk(KERN_INFO "PCSP: close called\n");
206 #endif
207 	pcsp_sync_stop(chip);
208 	chip->playback_substream = NULL;
209 	return 0;
210 }
211 
212 static int snd_pcsp_playback_hw_params(struct snd_pcm_substream *substream,
213 				       struct snd_pcm_hw_params *hw_params)
214 {
215 	struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
216 	int err;
217 	pcsp_sync_stop(chip);
218 	err = snd_pcm_lib_malloc_pages(substream,
219 				      params_buffer_bytes(hw_params));
220 	if (err < 0)
221 		return err;
222 	return 0;
223 }
224 
225 static int snd_pcsp_playback_hw_free(struct snd_pcm_substream *substream)
226 {
227 	struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
228 #if PCSP_DEBUG
229 	printk(KERN_INFO "PCSP: hw_free called\n");
230 #endif
231 	pcsp_sync_stop(chip);
232 	return snd_pcm_lib_free_pages(substream);
233 }
234 
235 static int snd_pcsp_playback_prepare(struct snd_pcm_substream *substream)
236 {
237 	struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
238 	pcsp_sync_stop(chip);
239 	chip->playback_ptr = 0;
240 	chip->period_ptr = 0;
241 	chip->fmt_size =
242 		snd_pcm_format_physical_width(substream->runtime->format) >> 3;
243 	chip->is_signed = snd_pcm_format_signed(substream->runtime->format);
244 #if PCSP_DEBUG
245 	printk(KERN_INFO "PCSP: prepare called, "
246 			"size=%zi psize=%zi f=%zi f1=%i fsize=%i\n",
247 			snd_pcm_lib_buffer_bytes(substream),
248 			snd_pcm_lib_period_bytes(substream),
249 			snd_pcm_lib_buffer_bytes(substream) /
250 			snd_pcm_lib_period_bytes(substream),
251 			substream->runtime->periods,
252 			chip->fmt_size);
253 #endif
254 	return 0;
255 }
256 
257 static int snd_pcsp_trigger(struct snd_pcm_substream *substream, int cmd)
258 {
259 	struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
260 #if PCSP_DEBUG
261 	printk(KERN_INFO "PCSP: trigger called\n");
262 #endif
263 	switch (cmd) {
264 	case SNDRV_PCM_TRIGGER_START:
265 	case SNDRV_PCM_TRIGGER_RESUME:
266 		return pcsp_start_playing(chip);
267 	case SNDRV_PCM_TRIGGER_STOP:
268 	case SNDRV_PCM_TRIGGER_SUSPEND:
269 		pcsp_stop_playing(chip);
270 		break;
271 	default:
272 		return -EINVAL;
273 	}
274 	return 0;
275 }
276 
277 static snd_pcm_uframes_t snd_pcsp_playback_pointer(struct snd_pcm_substream
278 						   *substream)
279 {
280 	struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
281 	unsigned int pos;
282 	spin_lock(&chip->substream_lock);
283 	pos = chip->playback_ptr;
284 	spin_unlock(&chip->substream_lock);
285 	return bytes_to_frames(substream->runtime, pos);
286 }
287 
288 static struct snd_pcm_hardware snd_pcsp_playback = {
289 	.info = (SNDRV_PCM_INFO_INTERLEAVED |
290 		 SNDRV_PCM_INFO_HALF_DUPLEX |
291 		 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID),
292 	.formats = (SNDRV_PCM_FMTBIT_U8
293 #if DMIX_WANTS_S16
294 		    | SNDRV_PCM_FMTBIT_S16_LE
295 #endif
296 	    ),
297 	.rates = SNDRV_PCM_RATE_KNOT,
298 	.rate_min = PCSP_DEFAULT_SRATE,
299 	.rate_max = PCSP_DEFAULT_SRATE,
300 	.channels_min = 1,
301 	.channels_max = 1,
302 	.buffer_bytes_max = PCSP_BUFFER_SIZE,
303 	.period_bytes_min = 64,
304 	.period_bytes_max = PCSP_MAX_PERIOD_SIZE,
305 	.periods_min = 2,
306 	.periods_max = PCSP_MAX_PERIODS,
307 	.fifo_size = 0,
308 };
309 
310 static int snd_pcsp_playback_open(struct snd_pcm_substream *substream)
311 {
312 	struct snd_pcsp *chip = snd_pcm_substream_chip(substream);
313 	struct snd_pcm_runtime *runtime = substream->runtime;
314 #if PCSP_DEBUG
315 	printk(KERN_INFO "PCSP: open called\n");
316 #endif
317 	if (atomic_read(&chip->timer_active)) {
318 		printk(KERN_ERR "PCSP: still active!!\n");
319 		return -EBUSY;
320 	}
321 	runtime->hw = snd_pcsp_playback;
322 	chip->playback_substream = substream;
323 	return 0;
324 }
325 
326 static struct snd_pcm_ops snd_pcsp_playback_ops = {
327 	.open = snd_pcsp_playback_open,
328 	.close = snd_pcsp_playback_close,
329 	.ioctl = snd_pcm_lib_ioctl,
330 	.hw_params = snd_pcsp_playback_hw_params,
331 	.hw_free = snd_pcsp_playback_hw_free,
332 	.prepare = snd_pcsp_playback_prepare,
333 	.trigger = snd_pcsp_trigger,
334 	.pointer = snd_pcsp_playback_pointer,
335 };
336 
337 int snd_pcsp_new_pcm(struct snd_pcsp *chip)
338 {
339 	int err;
340 
341 	err = snd_pcm_new(chip->card, "pcspeaker", 0, 1, 0, &chip->pcm);
342 	if (err < 0)
343 		return err;
344 
345 	snd_pcm_set_ops(chip->pcm, SNDRV_PCM_STREAM_PLAYBACK,
346 			&snd_pcsp_playback_ops);
347 
348 	chip->pcm->private_data = chip;
349 	chip->pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX;
350 	strcpy(chip->pcm->name, "pcsp");
351 
352 	snd_pcm_lib_preallocate_pages_for_all(chip->pcm,
353 					      SNDRV_DMA_TYPE_CONTINUOUS,
354 					      snd_dma_continuous_data
355 					      (GFP_KERNEL), PCSP_BUFFER_SIZE,
356 					      PCSP_BUFFER_SIZE);
357 
358 	return 0;
359 }
360