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9ab4d072 SS |
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 <sound/pcm.h> | |
9ab4d072 SS |
12 | #include <linux/interrupt.h> |
13 | #include <asm/io.h> | |
9ab4d072 SS |
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 | ||
4dfd7954 SS |
21 | #define DMIX_WANTS_S16 1 |
22 | ||
9ab4d072 SS |
23 | static void pcsp_start_timer(unsigned long dummy) |
24 | { | |
25 | hrtimer_start(&pcsp_chip.timer, ktime_set(0, 0), HRTIMER_MODE_REL); | |
26 | } | |
27 | ||
28 | /* | |
29 | * We need the hrtimer_start as a tasklet to avoid | |
30 | * the nasty locking problem. :( | |
31 | * The problem: | |
32 | * - The timer handler is called with the cpu_base->lock | |
33 | * already held by hrtimer code. | |
34 | * - snd_pcm_period_elapsed() takes the | |
35 | * substream->self_group.lock. | |
36 | * So far so good. | |
37 | * But the snd_pcsp_trigger() is called with the | |
38 | * substream->self_group.lock held, and it calls | |
39 | * hrtimer_start(), which takes the cpu_base->lock. | |
40 | * You see the problem. We have the code pathes | |
41 | * which take two locks in a reverse order. This | |
42 | * can deadlock and the lock validator complains. | |
43 | * The only solution I could find was to move the | |
44 | * hrtimer_start() into a tasklet. -stsp | |
45 | */ | |
a91605b8 | 46 | static DECLARE_TASKLET(pcsp_start_timer_tasklet, pcsp_start_timer, 0); |
9ab4d072 SS |
47 | |
48 | enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle) | |
49 | { | |
50 | unsigned long flags; | |
51 | unsigned char timer_cnt, val; | |
4dfd7954 | 52 | int fmt_size, periods_elapsed; |
9ab4d072 SS |
53 | u64 ns; |
54 | size_t period_bytes, buffer_bytes; | |
55 | struct snd_pcm_substream *substream; | |
56 | struct snd_pcm_runtime *runtime; | |
57 | struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer); | |
58 | ||
59 | if (chip->thalf) { | |
60 | outb(chip->val61, 0x61); | |
61 | chip->thalf = 0; | |
62 | if (!atomic_read(&chip->timer_active)) | |
63 | return HRTIMER_NORESTART; | |
64 | hrtimer_forward(&chip->timer, chip->timer.expires, | |
65 | ktime_set(0, chip->ns_rem)); | |
66 | return HRTIMER_RESTART; | |
67 | } | |
68 | ||
69 | /* hrtimer calls us from both hardirq and softirq contexts, | |
70 | * so irqsave :( */ | |
71 | spin_lock_irqsave(&chip->substream_lock, flags); | |
72 | /* Takashi Iwai says regarding this extra lock: | |
73 | ||
74 | If the irq handler handles some data on the DMA buffer, it should | |
75 | do snd_pcm_stream_lock(). | |
76 | That protects basically against all races among PCM callbacks, yes. | |
77 | However, there are two remaining issues: | |
78 | 1. The substream pointer you try to lock isn't protected _before_ | |
79 | this lock yet. | |
80 | 2. snd_pcm_period_elapsed() itself acquires the lock. | |
81 | The requirement of another lock is because of 1. When you get | |
82 | chip->playback_substream, it's not protected. | |
83 | Keeping this lock while snd_pcm_period_elapsed() assures the substream | |
84 | is still protected (at least, not released). And the other status is | |
85 | handled properly inside snd_pcm_stream_lock() in | |
86 | snd_pcm_period_elapsed(). | |
87 | ||
88 | */ | |
89 | if (!chip->playback_substream) | |
90 | goto exit_nr_unlock1; | |
91 | substream = chip->playback_substream; | |
92 | snd_pcm_stream_lock(substream); | |
93 | if (!atomic_read(&chip->timer_active)) | |
94 | goto exit_nr_unlock2; | |
95 | ||
96 | runtime = substream->runtime; | |
4dfd7954 SS |
97 | fmt_size = snd_pcm_format_physical_width(runtime->format) >> 3; |
98 | /* assume it is mono! */ | |
99 | val = runtime->dma_area[chip->playback_ptr + fmt_size - 1]; | |
100 | if (snd_pcm_format_signed(runtime->format)) | |
101 | val ^= 0x80; | |
9ab4d072 SS |
102 | timer_cnt = val * CUR_DIV() / 256; |
103 | ||
104 | if (timer_cnt && chip->enable) { | |
105 | spin_lock(&i8253_lock); | |
106 | if (!nforce_wa) { | |
107 | outb_p(chip->val61, 0x61); | |
108 | outb_p(timer_cnt, 0x42); | |
109 | outb(chip->val61 ^ 1, 0x61); | |
110 | } else { | |
111 | outb(chip->val61 ^ 2, 0x61); | |
112 | chip->thalf = 1; | |
113 | } | |
114 | spin_unlock(&i8253_lock); | |
115 | } | |
116 | ||
117 | period_bytes = snd_pcm_lib_period_bytes(substream); | |
118 | buffer_bytes = snd_pcm_lib_buffer_bytes(substream); | |
4dfd7954 | 119 | chip->playback_ptr += PCSP_INDEX_INC() * fmt_size; |
9ab4d072 SS |
120 | periods_elapsed = chip->playback_ptr - chip->period_ptr; |
121 | if (periods_elapsed < 0) { | |
122 | printk(KERN_WARNING "PCSP: playback_ptr inconsistent " | |
123 | "(%zi %zi %zi)\n", | |
124 | chip->playback_ptr, period_bytes, buffer_bytes); | |
125 | periods_elapsed += buffer_bytes; | |
126 | } | |
127 | periods_elapsed /= period_bytes; | |
128 | /* wrap the pointer _before_ calling snd_pcm_period_elapsed(), | |
129 | * or ALSA will BUG on us. */ | |
130 | chip->playback_ptr %= buffer_bytes; | |
131 | ||
132 | snd_pcm_stream_unlock(substream); | |
133 | ||
134 | if (periods_elapsed) { | |
135 | snd_pcm_period_elapsed(substream); | |
136 | chip->period_ptr += periods_elapsed * period_bytes; | |
137 | chip->period_ptr %= buffer_bytes; | |
138 | } | |
139 | ||
140 | spin_unlock_irqrestore(&chip->substream_lock, flags); | |
141 | ||
142 | if (!atomic_read(&chip->timer_active)) | |
143 | return HRTIMER_NORESTART; | |
144 | ||
145 | chip->ns_rem = PCSP_PERIOD_NS(); | |
146 | ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem); | |
147 | chip->ns_rem -= ns; | |
148 | hrtimer_forward(&chip->timer, chip->timer.expires, ktime_set(0, ns)); | |
149 | return HRTIMER_RESTART; | |
150 | ||
151 | exit_nr_unlock2: | |
152 | snd_pcm_stream_unlock(substream); | |
153 | exit_nr_unlock1: | |
154 | spin_unlock_irqrestore(&chip->substream_lock, flags); | |
155 | return HRTIMER_NORESTART; | |
156 | } | |
157 | ||
158 | static void pcsp_start_playing(struct snd_pcsp *chip) | |
159 | { | |
160 | #if PCSP_DEBUG | |
161 | printk(KERN_INFO "PCSP: start_playing called\n"); | |
162 | #endif | |
163 | if (atomic_read(&chip->timer_active)) { | |
164 | printk(KERN_ERR "PCSP: Timer already active\n"); | |
165 | return; | |
166 | } | |
167 | ||
168 | spin_lock(&i8253_lock); | |
169 | chip->val61 = inb(0x61) | 0x03; | |
170 | outb_p(0x92, 0x43); /* binary, mode 1, LSB only, ch 2 */ | |
171 | spin_unlock(&i8253_lock); | |
172 | atomic_set(&chip->timer_active, 1); | |
173 | chip->thalf = 0; | |
174 | ||
175 | tasklet_schedule(&pcsp_start_timer_tasklet); | |
176 | } | |
177 | ||
178 | static void pcsp_stop_playing(struct snd_pcsp *chip) | |
179 | { | |
180 | #if PCSP_DEBUG | |
181 | printk(KERN_INFO "PCSP: stop_playing called\n"); | |
182 | #endif | |
183 | if (!atomic_read(&chip->timer_active)) | |
184 | return; | |
185 | ||
186 | atomic_set(&chip->timer_active, 0); | |
187 | spin_lock(&i8253_lock); | |
188 | /* restore the timer */ | |
189 | outb_p(0xb6, 0x43); /* binary, mode 3, LSB/MSB, ch 2 */ | |
190 | outb(chip->val61 & 0xFC, 0x61); | |
191 | spin_unlock(&i8253_lock); | |
192 | } | |
193 | ||
194 | static int snd_pcsp_playback_close(struct snd_pcm_substream *substream) | |
195 | { | |
196 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
197 | #if PCSP_DEBUG | |
198 | printk(KERN_INFO "PCSP: close called\n"); | |
199 | #endif | |
200 | if (atomic_read(&chip->timer_active)) { | |
201 | printk(KERN_ERR "PCSP: timer still active\n"); | |
202 | pcsp_stop_playing(chip); | |
203 | } | |
204 | spin_lock_irq(&chip->substream_lock); | |
205 | chip->playback_substream = NULL; | |
206 | spin_unlock_irq(&chip->substream_lock); | |
207 | return 0; | |
208 | } | |
209 | ||
210 | static int snd_pcsp_playback_hw_params(struct snd_pcm_substream *substream, | |
211 | struct snd_pcm_hw_params *hw_params) | |
212 | { | |
213 | int err; | |
214 | err = snd_pcm_lib_malloc_pages(substream, | |
215 | params_buffer_bytes(hw_params)); | |
216 | if (err < 0) | |
217 | return err; | |
218 | return 0; | |
219 | } | |
220 | ||
221 | static int snd_pcsp_playback_hw_free(struct snd_pcm_substream *substream) | |
222 | { | |
223 | #if PCSP_DEBUG | |
224 | printk(KERN_INFO "PCSP: hw_free called\n"); | |
225 | #endif | |
226 | return snd_pcm_lib_free_pages(substream); | |
227 | } | |
228 | ||
229 | static int snd_pcsp_playback_prepare(struct snd_pcm_substream *substream) | |
230 | { | |
231 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
232 | #if PCSP_DEBUG | |
233 | printk(KERN_INFO "PCSP: prepare called, " | |
234 | "size=%zi psize=%zi f=%zi f1=%i\n", | |
235 | snd_pcm_lib_buffer_bytes(substream), | |
236 | snd_pcm_lib_period_bytes(substream), | |
237 | snd_pcm_lib_buffer_bytes(substream) / | |
238 | snd_pcm_lib_period_bytes(substream), | |
239 | substream->runtime->periods); | |
240 | #endif | |
241 | chip->playback_ptr = 0; | |
242 | chip->period_ptr = 0; | |
243 | return 0; | |
244 | } | |
245 | ||
246 | static int snd_pcsp_trigger(struct snd_pcm_substream *substream, int cmd) | |
247 | { | |
248 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
249 | #if PCSP_DEBUG | |
250 | printk(KERN_INFO "PCSP: trigger called\n"); | |
251 | #endif | |
252 | switch (cmd) { | |
253 | case SNDRV_PCM_TRIGGER_START: | |
254 | case SNDRV_PCM_TRIGGER_RESUME: | |
255 | pcsp_start_playing(chip); | |
256 | break; | |
257 | case SNDRV_PCM_TRIGGER_STOP: | |
258 | case SNDRV_PCM_TRIGGER_SUSPEND: | |
259 | pcsp_stop_playing(chip); | |
260 | break; | |
261 | default: | |
262 | return -EINVAL; | |
263 | } | |
264 | return 0; | |
265 | } | |
266 | ||
267 | static snd_pcm_uframes_t snd_pcsp_playback_pointer(struct snd_pcm_substream | |
268 | *substream) | |
269 | { | |
270 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
271 | return bytes_to_frames(substream->runtime, chip->playback_ptr); | |
272 | } | |
273 | ||
274 | static struct snd_pcm_hardware snd_pcsp_playback = { | |
275 | .info = (SNDRV_PCM_INFO_INTERLEAVED | | |
276 | SNDRV_PCM_INFO_HALF_DUPLEX | | |
277 | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID), | |
4dfd7954 SS |
278 | .formats = (SNDRV_PCM_FMTBIT_U8 |
279 | #if DMIX_WANTS_S16 | |
280 | | SNDRV_PCM_FMTBIT_S16_LE | |
281 | #endif | |
282 | ), | |
9ab4d072 SS |
283 | .rates = SNDRV_PCM_RATE_KNOT, |
284 | .rate_min = PCSP_DEFAULT_SRATE, | |
285 | .rate_max = PCSP_DEFAULT_SRATE, | |
286 | .channels_min = 1, | |
287 | .channels_max = 1, | |
288 | .buffer_bytes_max = PCSP_BUFFER_SIZE, | |
289 | .period_bytes_min = 64, | |
290 | .period_bytes_max = PCSP_MAX_PERIOD_SIZE, | |
291 | .periods_min = 2, | |
292 | .periods_max = PCSP_MAX_PERIODS, | |
293 | .fifo_size = 0, | |
294 | }; | |
295 | ||
296 | static int snd_pcsp_playback_open(struct snd_pcm_substream *substream) | |
297 | { | |
298 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
299 | struct snd_pcm_runtime *runtime = substream->runtime; | |
300 | #if PCSP_DEBUG | |
301 | printk(KERN_INFO "PCSP: open called\n"); | |
302 | #endif | |
303 | if (atomic_read(&chip->timer_active)) { | |
304 | printk(KERN_ERR "PCSP: still active!!\n"); | |
305 | return -EBUSY; | |
306 | } | |
307 | runtime->hw = snd_pcsp_playback; | |
1bc1f305 | 308 | spin_lock_irq(&chip->substream_lock); |
9ab4d072 | 309 | chip->playback_substream = substream; |
1bc1f305 | 310 | spin_unlock_irq(&chip->substream_lock); |
9ab4d072 SS |
311 | return 0; |
312 | } | |
313 | ||
314 | static struct snd_pcm_ops snd_pcsp_playback_ops = { | |
315 | .open = snd_pcsp_playback_open, | |
316 | .close = snd_pcsp_playback_close, | |
317 | .ioctl = snd_pcm_lib_ioctl, | |
318 | .hw_params = snd_pcsp_playback_hw_params, | |
319 | .hw_free = snd_pcsp_playback_hw_free, | |
320 | .prepare = snd_pcsp_playback_prepare, | |
321 | .trigger = snd_pcsp_trigger, | |
322 | .pointer = snd_pcsp_playback_pointer, | |
323 | }; | |
324 | ||
325 | int __devinit snd_pcsp_new_pcm(struct snd_pcsp *chip) | |
326 | { | |
327 | int err; | |
328 | ||
329 | err = snd_pcm_new(chip->card, "pcspeaker", 0, 1, 0, &chip->pcm); | |
330 | if (err < 0) | |
331 | return err; | |
332 | ||
333 | snd_pcm_set_ops(chip->pcm, SNDRV_PCM_STREAM_PLAYBACK, | |
334 | &snd_pcsp_playback_ops); | |
335 | ||
336 | chip->pcm->private_data = chip; | |
337 | chip->pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX; | |
338 | strcpy(chip->pcm->name, "pcsp"); | |
339 | ||
340 | snd_pcm_lib_preallocate_pages_for_all(chip->pcm, | |
341 | SNDRV_DMA_TYPE_CONTINUOUS, | |
342 | snd_dma_continuous_data | |
343 | (GFP_KERNEL), PCSP_BUFFER_SIZE, | |
344 | PCSP_BUFFER_SIZE); | |
345 | ||
346 | return 0; | |
347 | } |