1/*
2 * sound/soc/samsung/idma.c
3 *
4 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
5 *		http://www.samsung.com
6 *
7 * I2S0's Internal DMA driver
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/interrupt.h>
15#include <linux/platform_device.h>
16#include <linux/dma-mapping.h>
17#include <linux/slab.h>
18#include <linux/module.h>
19#include <sound/pcm.h>
20#include <sound/pcm_params.h>
21#include <sound/soc.h>
22
23#include "i2s.h"
24#include "idma.h"
25#include "dma.h"
26#include "i2s-regs.h"
27
28#define ST_RUNNING		(1<<0)
29#define ST_OPENED		(1<<1)
30
31static const struct snd_pcm_hardware idma_hardware = {
32	.info = SNDRV_PCM_INFO_INTERLEAVED |
33		    SNDRV_PCM_INFO_BLOCK_TRANSFER |
34		    SNDRV_PCM_INFO_MMAP |
35		    SNDRV_PCM_INFO_MMAP_VALID |
36		    SNDRV_PCM_INFO_PAUSE |
37		    SNDRV_PCM_INFO_RESUME,
38	.buffer_bytes_max = MAX_IDMA_BUFFER,
39	.period_bytes_min = 128,
40	.period_bytes_max = MAX_IDMA_PERIOD,
41	.periods_min = 1,
42	.periods_max = 2,
43};
44
45struct idma_ctrl {
46	spinlock_t	lock;
47	int		state;
48	dma_addr_t	start;
49	dma_addr_t	pos;
50	dma_addr_t	end;
51	dma_addr_t	period;
52	dma_addr_t	periodsz;
53	void		*token;
54	void		(*cb)(void *dt, int bytes_xfer);
55};
56
57static struct idma_info {
58	spinlock_t	lock;
59	void		 __iomem  *regs;
60	dma_addr_t	lp_tx_addr;
61} idma;
62
63static int idma_irq;
64
65static void idma_getpos(dma_addr_t *src)
66{
67	*src = idma.lp_tx_addr +
68		(readl(idma.regs + I2STRNCNT) & 0xffffff) * 4;
69}
70
71static int idma_enqueue(struct snd_pcm_substream *substream)
72{
73	struct snd_pcm_runtime *runtime = substream->runtime;
74	struct idma_ctrl *prtd = substream->runtime->private_data;
75	u32 val;
76
77	spin_lock(&prtd->lock);
78	prtd->token = (void *) substream;
79	spin_unlock(&prtd->lock);
80
81	/* Internal DMA Level0 Interrupt Address */
82	val = idma.lp_tx_addr + prtd->periodsz;
83	writel(val, idma.regs + I2SLVL0ADDR);
84
85	/* Start address0 of I2S internal DMA operation. */
86	val = idma.lp_tx_addr;
87	writel(val, idma.regs + I2SSTR0);
88
89	/*
90	 * Transfer block size for I2S internal DMA.
91	 * Should decide transfer size before start dma operation
92	 */
93	val = readl(idma.regs + I2SSIZE);
94	val &= ~(I2SSIZE_TRNMSK << I2SSIZE_SHIFT);
95	val |= (((runtime->dma_bytes >> 2) &
96			I2SSIZE_TRNMSK) << I2SSIZE_SHIFT);
97	writel(val, idma.regs + I2SSIZE);
98
99	val = readl(idma.regs + I2SAHB);
100	val |= AHB_INTENLVL0;
101	writel(val, idma.regs + I2SAHB);
102
103	return 0;
104}
105
106static void idma_setcallbk(struct snd_pcm_substream *substream,
107				void (*cb)(void *, int))
108{
109	struct idma_ctrl *prtd = substream->runtime->private_data;
110
111	spin_lock(&prtd->lock);
112	prtd->cb = cb;
113	spin_unlock(&prtd->lock);
114}
115
116static void idma_control(int op)
117{
118	u32 val = readl(idma.regs + I2SAHB);
119
120	spin_lock(&idma.lock);
121
122	switch (op) {
123	case LPAM_DMA_START:
124		val |= (AHB_INTENLVL0 | AHB_DMAEN);
125		break;
126	case LPAM_DMA_STOP:
127		val &= ~(AHB_INTENLVL0 | AHB_DMAEN);
128		break;
129	default:
130		spin_unlock(&idma.lock);
131		return;
132	}
133
134	writel(val, idma.regs + I2SAHB);
135	spin_unlock(&idma.lock);
136}
137
138static void idma_done(void *id, int bytes_xfer)
139{
140	struct snd_pcm_substream *substream = id;
141	struct idma_ctrl *prtd = substream->runtime->private_data;
142
143	if (prtd && (prtd->state & ST_RUNNING))
144		snd_pcm_period_elapsed(substream);
145}
146
147static int idma_hw_params(struct snd_pcm_substream *substream,
148				struct snd_pcm_hw_params *params)
149{
150	struct snd_pcm_runtime *runtime = substream->runtime;
151	struct idma_ctrl *prtd = substream->runtime->private_data;
152	u32 mod = readl(idma.regs + I2SMOD);
153	u32 ahb = readl(idma.regs + I2SAHB);
154
155	ahb |= (AHB_DMARLD | AHB_INTMASK);
156	mod |= MOD_TXS_IDMA;
157	writel(ahb, idma.regs + I2SAHB);
158	writel(mod, idma.regs + I2SMOD);
159
160	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
161	runtime->dma_bytes = params_buffer_bytes(params);
162
163	prtd->start = prtd->pos = runtime->dma_addr;
164	prtd->period = params_periods(params);
165	prtd->periodsz = params_period_bytes(params);
166	prtd->end = runtime->dma_addr + runtime->dma_bytes;
167
168	idma_setcallbk(substream, idma_done);
169
170	return 0;
171}
172
173static int idma_hw_free(struct snd_pcm_substream *substream)
174{
175	snd_pcm_set_runtime_buffer(substream, NULL);
176
177	return 0;
178}
179
180static int idma_prepare(struct snd_pcm_substream *substream)
181{
182	struct idma_ctrl *prtd = substream->runtime->private_data;
183
184	prtd->pos = prtd->start;
185
186	/* flush the DMA channel */
187	idma_control(LPAM_DMA_STOP);
188	idma_enqueue(substream);
189
190	return 0;
191}
192
193static int idma_trigger(struct snd_pcm_substream *substream, int cmd)
194{
195	struct idma_ctrl *prtd = substream->runtime->private_data;
196	int ret = 0;
197
198	spin_lock(&prtd->lock);
199
200	switch (cmd) {
201	case SNDRV_PCM_TRIGGER_RESUME:
202	case SNDRV_PCM_TRIGGER_START:
203	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
204		prtd->state |= ST_RUNNING;
205		idma_control(LPAM_DMA_START);
206		break;
207
208	case SNDRV_PCM_TRIGGER_SUSPEND:
209	case SNDRV_PCM_TRIGGER_STOP:
210	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
211		prtd->state &= ~ST_RUNNING;
212		idma_control(LPAM_DMA_STOP);
213		break;
214
215	default:
216		ret = -EINVAL;
217		break;
218	}
219
220	spin_unlock(&prtd->lock);
221
222	return ret;
223}
224
225static snd_pcm_uframes_t
226	idma_pointer(struct snd_pcm_substream *substream)
227{
228	struct snd_pcm_runtime *runtime = substream->runtime;
229	struct idma_ctrl *prtd = runtime->private_data;
230	dma_addr_t src;
231	unsigned long res;
232
233	spin_lock(&prtd->lock);
234
235	idma_getpos(&src);
236	res = src - prtd->start;
237
238	spin_unlock(&prtd->lock);
239
240	return bytes_to_frames(substream->runtime, res);
241}
242
243static int idma_mmap(struct snd_pcm_substream *substream,
244	struct vm_area_struct *vma)
245{
246	struct snd_pcm_runtime *runtime = substream->runtime;
247	unsigned long size, offset;
248	int ret;
249
250	/* From snd_pcm_lib_mmap_iomem */
251	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
252	size = vma->vm_end - vma->vm_start;
253	offset = vma->vm_pgoff << PAGE_SHIFT;
254	ret = io_remap_pfn_range(vma, vma->vm_start,
255			(runtime->dma_addr + offset) >> PAGE_SHIFT,
256			size, vma->vm_page_prot);
257
258	return ret;
259}
260
261static irqreturn_t iis_irq(int irqno, void *dev_id)
262{
263	struct idma_ctrl *prtd = (struct idma_ctrl *)dev_id;
264	u32 iisahb, val, addr;
265
266	iisahb  = readl(idma.regs + I2SAHB);
267
268	val = (iisahb & AHB_LVL0INT) ? AHB_CLRLVL0INT : 0;
269
270	if (val) {
271		iisahb |= val;
272		writel(iisahb, idma.regs + I2SAHB);
273
274		addr = readl(idma.regs + I2SLVL0ADDR) - idma.lp_tx_addr;
275		addr += prtd->periodsz;
276		addr %= (u32)(prtd->end - prtd->start);
277		addr += idma.lp_tx_addr;
278
279		writel(addr, idma.regs + I2SLVL0ADDR);
280
281		if (prtd->cb)
282			prtd->cb(prtd->token, prtd->period);
283	}
284
285	return IRQ_HANDLED;
286}
287
288static int idma_open(struct snd_pcm_substream *substream)
289{
290	struct snd_pcm_runtime *runtime = substream->runtime;
291	struct idma_ctrl *prtd;
292	int ret;
293
294	snd_soc_set_runtime_hwparams(substream, &idma_hardware);
295
296	prtd = kzalloc(sizeof(struct idma_ctrl), GFP_KERNEL);
297	if (prtd == NULL)
298		return -ENOMEM;
299
300	ret = request_irq(idma_irq, iis_irq, 0, "i2s", prtd);
301	if (ret < 0) {
302		pr_err("fail to claim i2s irq , ret = %d\n", ret);
303		kfree(prtd);
304		return ret;
305	}
306
307	spin_lock_init(&prtd->lock);
308
309	runtime->private_data = prtd;
310
311	return 0;
312}
313
314static int idma_close(struct snd_pcm_substream *substream)
315{
316	struct snd_pcm_runtime *runtime = substream->runtime;
317	struct idma_ctrl *prtd = runtime->private_data;
318
319	free_irq(idma_irq, prtd);
320
321	if (!prtd)
322		pr_err("idma_close called with prtd == NULL\n");
323
324	kfree(prtd);
325
326	return 0;
327}
328
329static struct snd_pcm_ops idma_ops = {
330	.open		= idma_open,
331	.close		= idma_close,
332	.ioctl		= snd_pcm_lib_ioctl,
333	.trigger	= idma_trigger,
334	.pointer	= idma_pointer,
335	.mmap		= idma_mmap,
336	.hw_params	= idma_hw_params,
337	.hw_free	= idma_hw_free,
338	.prepare	= idma_prepare,
339};
340
341static void idma_free(struct snd_pcm *pcm)
342{
343	struct snd_pcm_substream *substream;
344	struct snd_dma_buffer *buf;
345
346	substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
347	if (!substream)
348		return;
349
350	buf = &substream->dma_buffer;
351	if (!buf->area)
352		return;
353
354	iounmap((void __iomem *)buf->area);
355
356	buf->area = NULL;
357	buf->addr = 0;
358}
359
360static int preallocate_idma_buffer(struct snd_pcm *pcm, int stream)
361{
362	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
363	struct snd_dma_buffer *buf = &substream->dma_buffer;
364
365	buf->dev.dev = pcm->card->dev;
366	buf->private_data = NULL;
367
368	/* Assign PCM buffer pointers */
369	buf->dev.type = SNDRV_DMA_TYPE_CONTINUOUS;
370	buf->addr = idma.lp_tx_addr;
371	buf->bytes = idma_hardware.buffer_bytes_max;
372	buf->area = (unsigned char * __force)ioremap(buf->addr, buf->bytes);
373
374	return 0;
375}
376
377static int idma_new(struct snd_soc_pcm_runtime *rtd)
378{
379	struct snd_card *card = rtd->card->snd_card;
380	struct snd_pcm *pcm = rtd->pcm;
381	int ret;
382
383	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
384	if (ret)
385		return ret;
386
387	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
388		ret = preallocate_idma_buffer(pcm,
389				SNDRV_PCM_STREAM_PLAYBACK);
390	}
391
392	return ret;
393}
394
395void idma_reg_addr_init(void __iomem *regs, dma_addr_t addr)
396{
397	spin_lock_init(&idma.lock);
398	idma.regs = regs;
399	idma.lp_tx_addr = addr;
400}
401EXPORT_SYMBOL_GPL(idma_reg_addr_init);
402
403static struct snd_soc_platform_driver asoc_idma_platform = {
404	.ops = &idma_ops,
405	.pcm_new = idma_new,
406	.pcm_free = idma_free,
407};
408
409static int asoc_idma_platform_probe(struct platform_device *pdev)
410{
411	idma_irq = platform_get_irq(pdev, 0);
412	if (idma_irq < 0)
413		return idma_irq;
414
415	return devm_snd_soc_register_platform(&pdev->dev, &asoc_idma_platform);
416}
417
418static struct platform_driver asoc_idma_driver = {
419	.driver = {
420		.name = "samsung-idma",
421	},
422
423	.probe = asoc_idma_platform_probe,
424};
425
426module_platform_driver(asoc_idma_driver);
427
428MODULE_AUTHOR("Jaswinder Singh, <jassisinghbrar@gmail.com>");
429MODULE_DESCRIPTION("Samsung ASoC IDMA Driver");
430MODULE_LICENSE("GPL");
431