Commit | Line | Data |
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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 | ||
9ab4d072 SS |
21 | static void pcsp_start_timer(unsigned long dummy) |
22 | { | |
23 | hrtimer_start(&pcsp_chip.timer, ktime_set(0, 0), HRTIMER_MODE_REL); | |
24 | } | |
25 | ||
26 | /* | |
27 | * We need the hrtimer_start as a tasklet to avoid | |
28 | * the nasty locking problem. :( | |
29 | * The problem: | |
30 | * - The timer handler is called with the cpu_base->lock | |
31 | * already held by hrtimer code. | |
32 | * - snd_pcm_period_elapsed() takes the | |
33 | * substream->self_group.lock. | |
34 | * So far so good. | |
35 | * But the snd_pcsp_trigger() is called with the | |
36 | * substream->self_group.lock held, and it calls | |
37 | * hrtimer_start(), which takes the cpu_base->lock. | |
38 | * You see the problem. We have the code pathes | |
39 | * which take two locks in a reverse order. This | |
40 | * can deadlock and the lock validator complains. | |
41 | * The only solution I could find was to move the | |
42 | * hrtimer_start() into a tasklet. -stsp | |
43 | */ | |
a91605b8 | 44 | static DECLARE_TASKLET(pcsp_start_timer_tasklet, pcsp_start_timer, 0); |
9ab4d072 SS |
45 | |
46 | enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle) | |
47 | { | |
48 | unsigned long flags; | |
49 | unsigned char timer_cnt, val; | |
c81d80cb | 50 | int periods_elapsed; |
9ab4d072 SS |
51 | u64 ns; |
52 | size_t period_bytes, buffer_bytes; | |
53 | struct snd_pcm_substream *substream; | |
54 | struct snd_pcm_runtime *runtime; | |
55 | struct snd_pcsp *chip = container_of(handle, struct snd_pcsp, timer); | |
56 | ||
57 | if (chip->thalf) { | |
58 | outb(chip->val61, 0x61); | |
59 | chip->thalf = 0; | |
60 | if (!atomic_read(&chip->timer_active)) | |
61 | return HRTIMER_NORESTART; | |
62 | hrtimer_forward(&chip->timer, chip->timer.expires, | |
63 | ktime_set(0, chip->ns_rem)); | |
64 | return HRTIMER_RESTART; | |
65 | } | |
66 | ||
67 | /* hrtimer calls us from both hardirq and softirq contexts, | |
68 | * so irqsave :( */ | |
69 | spin_lock_irqsave(&chip->substream_lock, flags); | |
70 | /* Takashi Iwai says regarding this extra lock: | |
71 | ||
72 | If the irq handler handles some data on the DMA buffer, it should | |
73 | do snd_pcm_stream_lock(). | |
74 | That protects basically against all races among PCM callbacks, yes. | |
75 | However, there are two remaining issues: | |
76 | 1. The substream pointer you try to lock isn't protected _before_ | |
77 | this lock yet. | |
78 | 2. snd_pcm_period_elapsed() itself acquires the lock. | |
79 | The requirement of another lock is because of 1. When you get | |
80 | chip->playback_substream, it's not protected. | |
81 | Keeping this lock while snd_pcm_period_elapsed() assures the substream | |
82 | is still protected (at least, not released). And the other status is | |
83 | handled properly inside snd_pcm_stream_lock() in | |
84 | snd_pcm_period_elapsed(). | |
85 | ||
86 | */ | |
87 | if (!chip->playback_substream) | |
88 | goto exit_nr_unlock1; | |
89 | substream = chip->playback_substream; | |
90 | snd_pcm_stream_lock(substream); | |
91 | if (!atomic_read(&chip->timer_active)) | |
92 | goto exit_nr_unlock2; | |
93 | ||
94 | runtime = substream->runtime; | |
c81d80cb SS |
95 | /* assume it is u8 mono */ |
96 | val = runtime->dma_area[chip->playback_ptr]; | |
9ab4d072 SS |
97 | timer_cnt = val * CUR_DIV() / 256; |
98 | ||
99 | if (timer_cnt && chip->enable) { | |
100 | spin_lock(&i8253_lock); | |
101 | if (!nforce_wa) { | |
102 | outb_p(chip->val61, 0x61); | |
103 | outb_p(timer_cnt, 0x42); | |
104 | outb(chip->val61 ^ 1, 0x61); | |
105 | } else { | |
106 | outb(chip->val61 ^ 2, 0x61); | |
107 | chip->thalf = 1; | |
108 | } | |
109 | spin_unlock(&i8253_lock); | |
110 | } | |
111 | ||
112 | period_bytes = snd_pcm_lib_period_bytes(substream); | |
113 | buffer_bytes = snd_pcm_lib_buffer_bytes(substream); | |
c81d80cb | 114 | chip->playback_ptr += PCSP_INDEX_INC(); |
9ab4d072 SS |
115 | periods_elapsed = chip->playback_ptr - chip->period_ptr; |
116 | if (periods_elapsed < 0) { | |
117 | printk(KERN_WARNING "PCSP: playback_ptr inconsistent " | |
118 | "(%zi %zi %zi)\n", | |
119 | chip->playback_ptr, period_bytes, buffer_bytes); | |
120 | periods_elapsed += buffer_bytes; | |
121 | } | |
122 | periods_elapsed /= period_bytes; | |
123 | /* wrap the pointer _before_ calling snd_pcm_period_elapsed(), | |
124 | * or ALSA will BUG on us. */ | |
125 | chip->playback_ptr %= buffer_bytes; | |
126 | ||
127 | snd_pcm_stream_unlock(substream); | |
128 | ||
129 | if (periods_elapsed) { | |
130 | snd_pcm_period_elapsed(substream); | |
131 | chip->period_ptr += periods_elapsed * period_bytes; | |
132 | chip->period_ptr %= buffer_bytes; | |
133 | } | |
134 | ||
135 | spin_unlock_irqrestore(&chip->substream_lock, flags); | |
136 | ||
137 | if (!atomic_read(&chip->timer_active)) | |
138 | return HRTIMER_NORESTART; | |
139 | ||
140 | chip->ns_rem = PCSP_PERIOD_NS(); | |
141 | ns = (chip->thalf ? PCSP_CALC_NS(timer_cnt) : chip->ns_rem); | |
142 | chip->ns_rem -= ns; | |
143 | hrtimer_forward(&chip->timer, chip->timer.expires, ktime_set(0, ns)); | |
144 | return HRTIMER_RESTART; | |
145 | ||
146 | exit_nr_unlock2: | |
147 | snd_pcm_stream_unlock(substream); | |
148 | exit_nr_unlock1: | |
149 | spin_unlock_irqrestore(&chip->substream_lock, flags); | |
150 | return HRTIMER_NORESTART; | |
151 | } | |
152 | ||
153 | static void pcsp_start_playing(struct snd_pcsp *chip) | |
154 | { | |
155 | #if PCSP_DEBUG | |
156 | printk(KERN_INFO "PCSP: start_playing called\n"); | |
157 | #endif | |
158 | if (atomic_read(&chip->timer_active)) { | |
159 | printk(KERN_ERR "PCSP: Timer already active\n"); | |
160 | return; | |
161 | } | |
162 | ||
163 | spin_lock(&i8253_lock); | |
164 | chip->val61 = inb(0x61) | 0x03; | |
165 | outb_p(0x92, 0x43); /* binary, mode 1, LSB only, ch 2 */ | |
166 | spin_unlock(&i8253_lock); | |
167 | atomic_set(&chip->timer_active, 1); | |
168 | chip->thalf = 0; | |
169 | ||
170 | tasklet_schedule(&pcsp_start_timer_tasklet); | |
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 | 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 | spin_unlock(&i8253_lock); | |
187 | } | |
188 | ||
189 | static int snd_pcsp_playback_close(struct snd_pcm_substream *substream) | |
190 | { | |
191 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
192 | #if PCSP_DEBUG | |
193 | printk(KERN_INFO "PCSP: close called\n"); | |
194 | #endif | |
195 | if (atomic_read(&chip->timer_active)) { | |
196 | printk(KERN_ERR "PCSP: timer still active\n"); | |
197 | pcsp_stop_playing(chip); | |
198 | } | |
199 | spin_lock_irq(&chip->substream_lock); | |
200 | chip->playback_substream = NULL; | |
201 | spin_unlock_irq(&chip->substream_lock); | |
202 | return 0; | |
203 | } | |
204 | ||
205 | static int snd_pcsp_playback_hw_params(struct snd_pcm_substream *substream, | |
206 | struct snd_pcm_hw_params *hw_params) | |
207 | { | |
208 | int err; | |
209 | err = snd_pcm_lib_malloc_pages(substream, | |
210 | params_buffer_bytes(hw_params)); | |
211 | if (err < 0) | |
212 | return err; | |
213 | return 0; | |
214 | } | |
215 | ||
216 | static int snd_pcsp_playback_hw_free(struct snd_pcm_substream *substream) | |
217 | { | |
218 | #if PCSP_DEBUG | |
219 | printk(KERN_INFO "PCSP: hw_free called\n"); | |
220 | #endif | |
221 | return snd_pcm_lib_free_pages(substream); | |
222 | } | |
223 | ||
224 | static int snd_pcsp_playback_prepare(struct snd_pcm_substream *substream) | |
225 | { | |
226 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
227 | #if PCSP_DEBUG | |
228 | printk(KERN_INFO "PCSP: prepare called, " | |
229 | "size=%zi psize=%zi f=%zi f1=%i\n", | |
230 | snd_pcm_lib_buffer_bytes(substream), | |
231 | snd_pcm_lib_period_bytes(substream), | |
232 | snd_pcm_lib_buffer_bytes(substream) / | |
233 | snd_pcm_lib_period_bytes(substream), | |
234 | substream->runtime->periods); | |
235 | #endif | |
236 | chip->playback_ptr = 0; | |
237 | chip->period_ptr = 0; | |
238 | return 0; | |
239 | } | |
240 | ||
241 | static int snd_pcsp_trigger(struct snd_pcm_substream *substream, int cmd) | |
242 | { | |
243 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
244 | #if PCSP_DEBUG | |
245 | printk(KERN_INFO "PCSP: trigger called\n"); | |
246 | #endif | |
247 | switch (cmd) { | |
248 | case SNDRV_PCM_TRIGGER_START: | |
249 | case SNDRV_PCM_TRIGGER_RESUME: | |
250 | pcsp_start_playing(chip); | |
251 | break; | |
252 | case SNDRV_PCM_TRIGGER_STOP: | |
253 | case SNDRV_PCM_TRIGGER_SUSPEND: | |
254 | pcsp_stop_playing(chip); | |
255 | break; | |
256 | default: | |
257 | return -EINVAL; | |
258 | } | |
259 | return 0; | |
260 | } | |
261 | ||
262 | static snd_pcm_uframes_t snd_pcsp_playback_pointer(struct snd_pcm_substream | |
263 | *substream) | |
264 | { | |
265 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
266 | return bytes_to_frames(substream->runtime, chip->playback_ptr); | |
267 | } | |
268 | ||
269 | static struct snd_pcm_hardware snd_pcsp_playback = { | |
270 | .info = (SNDRV_PCM_INFO_INTERLEAVED | | |
271 | SNDRV_PCM_INFO_HALF_DUPLEX | | |
272 | SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID), | |
c81d80cb | 273 | .formats = SNDRV_PCM_FMTBIT_U8, |
9ab4d072 SS |
274 | .rates = SNDRV_PCM_RATE_KNOT, |
275 | .rate_min = PCSP_DEFAULT_SRATE, | |
276 | .rate_max = PCSP_DEFAULT_SRATE, | |
277 | .channels_min = 1, | |
278 | .channels_max = 1, | |
279 | .buffer_bytes_max = PCSP_BUFFER_SIZE, | |
280 | .period_bytes_min = 64, | |
281 | .period_bytes_max = PCSP_MAX_PERIOD_SIZE, | |
282 | .periods_min = 2, | |
283 | .periods_max = PCSP_MAX_PERIODS, | |
284 | .fifo_size = 0, | |
285 | }; | |
286 | ||
287 | static int snd_pcsp_playback_open(struct snd_pcm_substream *substream) | |
288 | { | |
289 | struct snd_pcsp *chip = snd_pcm_substream_chip(substream); | |
290 | struct snd_pcm_runtime *runtime = substream->runtime; | |
291 | #if PCSP_DEBUG | |
292 | printk(KERN_INFO "PCSP: open called\n"); | |
293 | #endif | |
294 | if (atomic_read(&chip->timer_active)) { | |
295 | printk(KERN_ERR "PCSP: still active!!\n"); | |
296 | return -EBUSY; | |
297 | } | |
298 | runtime->hw = snd_pcsp_playback; | |
1bc1f305 | 299 | spin_lock_irq(&chip->substream_lock); |
9ab4d072 | 300 | chip->playback_substream = substream; |
1bc1f305 | 301 | spin_unlock_irq(&chip->substream_lock); |
9ab4d072 SS |
302 | return 0; |
303 | } | |
304 | ||
305 | static struct snd_pcm_ops snd_pcsp_playback_ops = { | |
306 | .open = snd_pcsp_playback_open, | |
307 | .close = snd_pcsp_playback_close, | |
308 | .ioctl = snd_pcm_lib_ioctl, | |
309 | .hw_params = snd_pcsp_playback_hw_params, | |
310 | .hw_free = snd_pcsp_playback_hw_free, | |
311 | .prepare = snd_pcsp_playback_prepare, | |
312 | .trigger = snd_pcsp_trigger, | |
313 | .pointer = snd_pcsp_playback_pointer, | |
314 | }; | |
315 | ||
316 | int __devinit snd_pcsp_new_pcm(struct snd_pcsp *chip) | |
317 | { | |
318 | int err; | |
319 | ||
320 | err = snd_pcm_new(chip->card, "pcspeaker", 0, 1, 0, &chip->pcm); | |
321 | if (err < 0) | |
322 | return err; | |
323 | ||
324 | snd_pcm_set_ops(chip->pcm, SNDRV_PCM_STREAM_PLAYBACK, | |
325 | &snd_pcsp_playback_ops); | |
326 | ||
327 | chip->pcm->private_data = chip; | |
328 | chip->pcm->info_flags = SNDRV_PCM_INFO_HALF_DUPLEX; | |
329 | strcpy(chip->pcm->name, "pcsp"); | |
330 | ||
331 | snd_pcm_lib_preallocate_pages_for_all(chip->pcm, | |
332 | SNDRV_DMA_TYPE_CONTINUOUS, | |
333 | snd_dma_continuous_data | |
334 | (GFP_KERNEL), PCSP_BUFFER_SIZE, | |
335 | PCSP_BUFFER_SIZE); | |
336 | ||
337 | return 0; | |
338 | } |