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