xref: /openbmc/linux/sound/soc/fsl/imx-pcm-fiq.c (revision 95e9fd10)
1 /*
2  * imx-pcm-fiq.c  --  ALSA Soc Audio Layer
3  *
4  * Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
5  *
6  * This code is based on code copyrighted by Freescale,
7  * Liam Girdwood, Javier Martin and probably others.
8  *
9  *  This program is free software; you can redistribute  it and/or modify it
10  *  under  the terms of  the GNU General  Public License as published by the
11  *  Free Software Foundation;  either version 2 of the  License, or (at your
12  *  option) any later version.
13  */
14 #include <linux/clk.h>
15 #include <linux/delay.h>
16 #include <linux/device.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/init.h>
19 #include <linux/interrupt.h>
20 #include <linux/module.h>
21 #include <linux/platform_device.h>
22 #include <linux/slab.h>
23 
24 #include <sound/core.h>
25 #include <sound/initval.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
28 #include <sound/soc.h>
29 
30 #include <asm/fiq.h>
31 
32 #include <mach/irqs.h>
33 #include <mach/ssi.h>
34 
35 #include "imx-ssi.h"
36 
37 struct imx_pcm_runtime_data {
38 	int period;
39 	int periods;
40 	unsigned long offset;
41 	unsigned long last_offset;
42 	unsigned long size;
43 	struct hrtimer hrt;
44 	int poll_time_ns;
45 	struct snd_pcm_substream *substream;
46 	atomic_t running;
47 };
48 
49 static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt)
50 {
51 	struct imx_pcm_runtime_data *iprtd =
52 		container_of(hrt, struct imx_pcm_runtime_data, hrt);
53 	struct snd_pcm_substream *substream = iprtd->substream;
54 	struct snd_pcm_runtime *runtime = substream->runtime;
55 	struct pt_regs regs;
56 	unsigned long delta;
57 
58 	if (!atomic_read(&iprtd->running))
59 		return HRTIMER_NORESTART;
60 
61 	get_fiq_regs(&regs);
62 
63 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
64 		iprtd->offset = regs.ARM_r8 & 0xffff;
65 	else
66 		iprtd->offset = regs.ARM_r9 & 0xffff;
67 
68 	/* How much data have we transferred since the last period report? */
69 	if (iprtd->offset >= iprtd->last_offset)
70 		delta = iprtd->offset - iprtd->last_offset;
71 	else
72 		delta = runtime->buffer_size + iprtd->offset
73 			- iprtd->last_offset;
74 
75 	/* If we've transferred at least a period then report it and
76 	 * reset our poll time */
77 	if (delta >= iprtd->period) {
78 		snd_pcm_period_elapsed(substream);
79 		iprtd->last_offset = iprtd->offset;
80 	}
81 
82 	hrtimer_forward_now(hrt, ns_to_ktime(iprtd->poll_time_ns));
83 
84 	return HRTIMER_RESTART;
85 }
86 
87 static struct fiq_handler fh = {
88 	.name		= DRV_NAME,
89 };
90 
91 static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
92 				struct snd_pcm_hw_params *params)
93 {
94 	struct snd_pcm_runtime *runtime = substream->runtime;
95 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
96 
97 	iprtd->size = params_buffer_bytes(params);
98 	iprtd->periods = params_periods(params);
99 	iprtd->period = params_period_bytes(params) ;
100 	iprtd->offset = 0;
101 	iprtd->last_offset = 0;
102 	iprtd->poll_time_ns = 1000000000 / params_rate(params) *
103 				params_period_size(params);
104 	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
105 
106 	return 0;
107 }
108 
109 static int snd_imx_pcm_prepare(struct snd_pcm_substream *substream)
110 {
111 	struct snd_pcm_runtime *runtime = substream->runtime;
112 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
113 	struct pt_regs regs;
114 
115 	get_fiq_regs(&regs);
116 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
117 		regs.ARM_r8 = (iprtd->period * iprtd->periods - 1) << 16;
118 	else
119 		regs.ARM_r9 = (iprtd->period * iprtd->periods - 1) << 16;
120 
121 	set_fiq_regs(&regs);
122 
123 	return 0;
124 }
125 
126 static int fiq_enable;
127 static int imx_pcm_fiq;
128 
129 static int snd_imx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
130 {
131 	struct snd_pcm_runtime *runtime = substream->runtime;
132 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
133 
134 	switch (cmd) {
135 	case SNDRV_PCM_TRIGGER_START:
136 	case SNDRV_PCM_TRIGGER_RESUME:
137 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
138 		atomic_set(&iprtd->running, 1);
139 		hrtimer_start(&iprtd->hrt, ns_to_ktime(iprtd->poll_time_ns),
140 		      HRTIMER_MODE_REL);
141 		if (++fiq_enable == 1)
142 			enable_fiq(imx_pcm_fiq);
143 
144 		break;
145 
146 	case SNDRV_PCM_TRIGGER_STOP:
147 	case SNDRV_PCM_TRIGGER_SUSPEND:
148 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
149 		atomic_set(&iprtd->running, 0);
150 
151 		if (--fiq_enable == 0)
152 			disable_fiq(imx_pcm_fiq);
153 
154 		break;
155 	default:
156 		return -EINVAL;
157 	}
158 
159 	return 0;
160 }
161 
162 static snd_pcm_uframes_t snd_imx_pcm_pointer(struct snd_pcm_substream *substream)
163 {
164 	struct snd_pcm_runtime *runtime = substream->runtime;
165 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
166 
167 	return bytes_to_frames(substream->runtime, iprtd->offset);
168 }
169 
170 static struct snd_pcm_hardware snd_imx_hardware = {
171 	.info = SNDRV_PCM_INFO_INTERLEAVED |
172 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
173 		SNDRV_PCM_INFO_MMAP |
174 		SNDRV_PCM_INFO_MMAP_VALID |
175 		SNDRV_PCM_INFO_PAUSE |
176 		SNDRV_PCM_INFO_RESUME,
177 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
178 	.rate_min = 8000,
179 	.channels_min = 2,
180 	.channels_max = 2,
181 	.buffer_bytes_max = IMX_SSI_DMABUF_SIZE,
182 	.period_bytes_min = 128,
183 	.period_bytes_max = 16 * 1024,
184 	.periods_min = 4,
185 	.periods_max = 255,
186 	.fifo_size = 0,
187 };
188 
189 static int snd_imx_open(struct snd_pcm_substream *substream)
190 {
191 	struct snd_pcm_runtime *runtime = substream->runtime;
192 	struct imx_pcm_runtime_data *iprtd;
193 	int ret;
194 
195 	iprtd = kzalloc(sizeof(*iprtd), GFP_KERNEL);
196 	if (iprtd == NULL)
197 		return -ENOMEM;
198 	runtime->private_data = iprtd;
199 
200 	iprtd->substream = substream;
201 
202 	atomic_set(&iprtd->running, 0);
203 	hrtimer_init(&iprtd->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
204 	iprtd->hrt.function = snd_hrtimer_callback;
205 
206 	ret = snd_pcm_hw_constraint_integer(substream->runtime,
207 			SNDRV_PCM_HW_PARAM_PERIODS);
208 	if (ret < 0) {
209 		kfree(iprtd);
210 		return ret;
211 	}
212 
213 	snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
214 	return 0;
215 }
216 
217 static int snd_imx_close(struct snd_pcm_substream *substream)
218 {
219 	struct snd_pcm_runtime *runtime = substream->runtime;
220 	struct imx_pcm_runtime_data *iprtd = runtime->private_data;
221 
222 	hrtimer_cancel(&iprtd->hrt);
223 
224 	kfree(iprtd);
225 
226 	return 0;
227 }
228 
229 static struct snd_pcm_ops imx_pcm_ops = {
230 	.open		= snd_imx_open,
231 	.close		= snd_imx_close,
232 	.ioctl		= snd_pcm_lib_ioctl,
233 	.hw_params	= snd_imx_pcm_hw_params,
234 	.prepare	= snd_imx_pcm_prepare,
235 	.trigger	= snd_imx_pcm_trigger,
236 	.pointer	= snd_imx_pcm_pointer,
237 	.mmap		= snd_imx_pcm_mmap,
238 };
239 
240 static int ssi_irq = 0;
241 
242 static int imx_pcm_fiq_new(struct snd_soc_pcm_runtime *rtd)
243 {
244 	struct snd_pcm *pcm = rtd->pcm;
245 	struct snd_pcm_substream *substream;
246 	int ret;
247 
248 	ret = imx_pcm_new(rtd);
249 	if (ret)
250 		return ret;
251 
252 	substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
253 	if (substream) {
254 		struct snd_dma_buffer *buf = &substream->dma_buffer;
255 
256 		imx_ssi_fiq_tx_buffer = (unsigned long)buf->area;
257 	}
258 
259 	substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
260 	if (substream) {
261 		struct snd_dma_buffer *buf = &substream->dma_buffer;
262 
263 		imx_ssi_fiq_rx_buffer = (unsigned long)buf->area;
264 	}
265 
266 	set_fiq_handler(&imx_ssi_fiq_start,
267 		&imx_ssi_fiq_end - &imx_ssi_fiq_start);
268 
269 	return 0;
270 }
271 
272 static void imx_pcm_fiq_free(struct snd_pcm *pcm)
273 {
274 	mxc_set_irq_fiq(ssi_irq, 0);
275 	release_fiq(&fh);
276 	imx_pcm_free(pcm);
277 }
278 
279 static struct snd_soc_platform_driver imx_soc_platform_fiq = {
280 	.ops		= &imx_pcm_ops,
281 	.pcm_new	= imx_pcm_fiq_new,
282 	.pcm_free	= imx_pcm_fiq_free,
283 };
284 
285 static int __devinit imx_soc_platform_probe(struct platform_device *pdev)
286 {
287 	struct imx_ssi *ssi = platform_get_drvdata(pdev);
288 	int ret;
289 
290 	ret = claim_fiq(&fh);
291 	if (ret) {
292 		dev_err(&pdev->dev, "failed to claim fiq: %d", ret);
293 		return ret;
294 	}
295 
296 	mxc_set_irq_fiq(ssi->irq, 1);
297 	ssi_irq = ssi->irq;
298 
299 	imx_pcm_fiq = ssi->irq;
300 
301 	imx_ssi_fiq_base = (unsigned long)ssi->base;
302 
303 	ssi->dma_params_tx.burstsize = 4;
304 	ssi->dma_params_rx.burstsize = 6;
305 
306 	ret = snd_soc_register_platform(&pdev->dev, &imx_soc_platform_fiq);
307 	if (ret)
308 		goto failed_register;
309 
310 	return 0;
311 
312 failed_register:
313 	mxc_set_irq_fiq(ssi_irq, 0);
314 	release_fiq(&fh);
315 
316 	return ret;
317 }
318 
319 static int __devexit imx_soc_platform_remove(struct platform_device *pdev)
320 {
321 	snd_soc_unregister_platform(&pdev->dev);
322 	return 0;
323 }
324 
325 static struct platform_driver imx_pcm_driver = {
326 	.driver = {
327 			.name = "imx-fiq-pcm-audio",
328 			.owner = THIS_MODULE,
329 	},
330 
331 	.probe = imx_soc_platform_probe,
332 	.remove = __devexit_p(imx_soc_platform_remove),
333 };
334 
335 module_platform_driver(imx_pcm_driver);
336 
337 MODULE_LICENSE("GPL");
338