1// SPDX-License-Identifier: GPL-2.0+
2//
3// idma.c - I2S0 internal DMA driver
4//
5// Copyright (c) 2011 Samsung Electronics Co., Ltd.
6//		http://www.samsung.com
7
8#include <linux/interrupt.h>
9#include <linux/platform_device.h>
10#include <linux/dma-mapping.h>
11#include <linux/slab.h>
12#include <linux/module.h>
13#include <sound/pcm.h>
14#include <sound/pcm_params.h>
15#include <sound/soc.h>
16
17#include "i2s.h"
18#include "idma.h"
19#include "i2s-regs.h"
20
21#define ST_RUNNING		(1<<0)
22#define ST_OPENED		(1<<1)
23
24static const struct snd_pcm_hardware idma_hardware = {
25	.info = SNDRV_PCM_INFO_INTERLEAVED |
26		    SNDRV_PCM_INFO_BLOCK_TRANSFER |
27		    SNDRV_PCM_INFO_MMAP |
28		    SNDRV_PCM_INFO_MMAP_VALID |
29		    SNDRV_PCM_INFO_PAUSE |
30		    SNDRV_PCM_INFO_RESUME,
31	.buffer_bytes_max = MAX_IDMA_BUFFER,
32	.period_bytes_min = 128,
33	.period_bytes_max = MAX_IDMA_PERIOD,
34	.periods_min = 1,
35	.periods_max = 2,
36};
37
38struct idma_ctrl {
39	spinlock_t	lock;
40	int		state;
41	dma_addr_t	start;
42	dma_addr_t	pos;
43	dma_addr_t	end;
44	dma_addr_t	period;
45	dma_addr_t	periodsz;
46	void		*token;
47	void		(*cb)(void *dt, int bytes_xfer);
48};
49
50static struct idma_info {
51	spinlock_t	lock;
52	void		 __iomem  *regs;
53	dma_addr_t	lp_tx_addr;
54} idma;
55
56static int idma_irq;
57
58static void idma_getpos(dma_addr_t *src)
59{
60	*src = idma.lp_tx_addr +
61		(readl(idma.regs + I2STRNCNT) & 0xffffff) * 4;
62}
63
64static int idma_enqueue(struct snd_pcm_substream *substream)
65{
66	struct snd_pcm_runtime *runtime = substream->runtime;
67	struct idma_ctrl *prtd = substream->runtime->private_data;
68	u32 val;
69
70	spin_lock(&prtd->lock);
71	prtd->token = (void *) substream;
72	spin_unlock(&prtd->lock);
73
74	/* Internal DMA Level0 Interrupt Address */
75	val = idma.lp_tx_addr + prtd->periodsz;
76	writel(val, idma.regs + I2SLVL0ADDR);
77
78	/* Start address0 of I2S internal DMA operation. */
79	val = idma.lp_tx_addr;
80	writel(val, idma.regs + I2SSTR0);
81
82	/*
83	 * Transfer block size for I2S internal DMA.
84	 * Should decide transfer size before start dma operation
85	 */
86	val = readl(idma.regs + I2SSIZE);
87	val &= ~(I2SSIZE_TRNMSK << I2SSIZE_SHIFT);
88	val |= (((runtime->dma_bytes >> 2) &
89			I2SSIZE_TRNMSK) << I2SSIZE_SHIFT);
90	writel(val, idma.regs + I2SSIZE);
91
92	val = readl(idma.regs + I2SAHB);
93	val |= AHB_INTENLVL0;
94	writel(val, idma.regs + I2SAHB);
95
96	return 0;
97}
98
99static void idma_setcallbk(struct snd_pcm_substream *substream,
100				void (*cb)(void *, int))
101{
102	struct idma_ctrl *prtd = substream->runtime->private_data;
103
104	spin_lock(&prtd->lock);
105	prtd->cb = cb;
106	spin_unlock(&prtd->lock);
107}
108
109static void idma_control(int op)
110{
111	u32 val = readl(idma.regs + I2SAHB);
112
113	spin_lock(&idma.lock);
114
115	switch (op) {
116	case LPAM_DMA_START:
117		val |= (AHB_INTENLVL0 | AHB_DMAEN);
118		break;
119	case LPAM_DMA_STOP:
120		val &= ~(AHB_INTENLVL0 | AHB_DMAEN);
121		break;
122	default:
123		spin_unlock(&idma.lock);
124		return;
125	}
126
127	writel(val, idma.regs + I2SAHB);
128	spin_unlock(&idma.lock);
129}
130
131static void idma_done(void *id, int bytes_xfer)
132{
133	struct snd_pcm_substream *substream = id;
134	struct idma_ctrl *prtd = substream->runtime->private_data;
135
136	if (prtd && (prtd->state & ST_RUNNING))
137		snd_pcm_period_elapsed(substream);
138}
139
140static int idma_hw_params(struct snd_soc_component *component,
141			  struct snd_pcm_substream *substream,
142			  struct snd_pcm_hw_params *params)
143{
144	struct snd_pcm_runtime *runtime = substream->runtime;
145	struct idma_ctrl *prtd = substream->runtime->private_data;
146	u32 mod = readl(idma.regs + I2SMOD);
147	u32 ahb = readl(idma.regs + I2SAHB);
148
149	ahb |= (AHB_DMARLD | AHB_INTMASK);
150	mod |= MOD_TXS_IDMA;
151	writel(ahb, idma.regs + I2SAHB);
152	writel(mod, idma.regs + I2SMOD);
153
154	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
155	runtime->dma_bytes = params_buffer_bytes(params);
156
157	prtd->start = prtd->pos = runtime->dma_addr;
158	prtd->period = params_periods(params);
159	prtd->periodsz = params_period_bytes(params);
160	prtd->end = runtime->dma_addr + runtime->dma_bytes;
161
162	idma_setcallbk(substream, idma_done);
163
164	return 0;
165}
166
167static int idma_hw_free(struct snd_soc_component *component,
168			struct snd_pcm_substream *substream)
169{
170	snd_pcm_set_runtime_buffer(substream, NULL);
171
172	return 0;
173}
174
175static int idma_prepare(struct snd_soc_component *component,
176			struct snd_pcm_substream *substream)
177{
178	struct idma_ctrl *prtd = substream->runtime->private_data;
179
180	prtd->pos = prtd->start;
181
182	/* flush the DMA channel */
183	idma_control(LPAM_DMA_STOP);
184	idma_enqueue(substream);
185
186	return 0;
187}
188
189static int idma_trigger(struct snd_soc_component *component,
190			struct snd_pcm_substream *substream, int cmd)
191{
192	struct idma_ctrl *prtd = substream->runtime->private_data;
193	int ret = 0;
194
195	spin_lock(&prtd->lock);
196
197	switch (cmd) {
198	case SNDRV_PCM_TRIGGER_RESUME:
199	case SNDRV_PCM_TRIGGER_START:
200	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
201		prtd->state |= ST_RUNNING;
202		idma_control(LPAM_DMA_START);
203		break;
204
205	case SNDRV_PCM_TRIGGER_SUSPEND:
206	case SNDRV_PCM_TRIGGER_STOP:
207	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
208		prtd->state &= ~ST_RUNNING;
209		idma_control(LPAM_DMA_STOP);
210		break;
211
212	default:
213		ret = -EINVAL;
214		break;
215	}
216
217	spin_unlock(&prtd->lock);
218
219	return ret;
220}
221
222static snd_pcm_uframes_t
223idma_pointer(struct snd_soc_component *component,
224	     struct snd_pcm_substream *substream)
225{
226	struct snd_pcm_runtime *runtime = substream->runtime;
227	struct idma_ctrl *prtd = runtime->private_data;
228	dma_addr_t src;
229	unsigned long res;
230
231	spin_lock(&prtd->lock);
232
233	idma_getpos(&src);
234	res = src - prtd->start;
235
236	spin_unlock(&prtd->lock);
237
238	return bytes_to_frames(substream->runtime, res);
239}
240
241static int idma_mmap(struct snd_soc_component *component,
242		     struct snd_pcm_substream *substream,
243	struct vm_area_struct *vma)
244{
245	struct snd_pcm_runtime *runtime = substream->runtime;
246	unsigned long size, offset;
247
248	/* From snd_pcm_lib_mmap_iomem */
249	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
250	size = vma->vm_end - vma->vm_start;
251	offset = vma->vm_pgoff << PAGE_SHIFT;
252	return io_remap_pfn_range(vma, vma->vm_start,
253			(runtime->dma_addr + offset) >> PAGE_SHIFT,
254			size, vma->vm_page_prot);
255}
256
257static irqreturn_t iis_irq(int irqno, void *dev_id)
258{
259	struct idma_ctrl *prtd = (struct idma_ctrl *)dev_id;
260	u32 iisahb, val, addr;
261
262	iisahb  = readl(idma.regs + I2SAHB);
263
264	val = (iisahb & AHB_LVL0INT) ? AHB_CLRLVL0INT : 0;
265
266	if (val) {
267		iisahb |= val;
268		writel(iisahb, idma.regs + I2SAHB);
269
270		addr = readl(idma.regs + I2SLVL0ADDR) - idma.lp_tx_addr;
271		addr += prtd->periodsz;
272		addr %= (u32)(prtd->end - prtd->start);
273		addr += idma.lp_tx_addr;
274
275		writel(addr, idma.regs + I2SLVL0ADDR);
276
277		if (prtd->cb)
278			prtd->cb(prtd->token, prtd->period);
279	}
280
281	return IRQ_HANDLED;
282}
283
284static int idma_open(struct snd_soc_component *component,
285		     struct snd_pcm_substream *substream)
286{
287	struct snd_pcm_runtime *runtime = substream->runtime;
288	struct idma_ctrl *prtd;
289	int ret;
290
291	snd_soc_set_runtime_hwparams(substream, &idma_hardware);
292
293	prtd = kzalloc(sizeof(struct idma_ctrl), GFP_KERNEL);
294	if (prtd == NULL)
295		return -ENOMEM;
296
297	ret = request_irq(idma_irq, iis_irq, 0, "i2s", prtd);
298	if (ret < 0) {
299		pr_err("fail to claim i2s irq , ret = %d\n", ret);
300		kfree(prtd);
301		return ret;
302	}
303
304	spin_lock_init(&prtd->lock);
305
306	runtime->private_data = prtd;
307
308	return 0;
309}
310
311static int idma_close(struct snd_soc_component *component,
312		      struct snd_pcm_substream *substream)
313{
314	struct snd_pcm_runtime *runtime = substream->runtime;
315	struct idma_ctrl *prtd = runtime->private_data;
316
317	free_irq(idma_irq, prtd);
318
319	if (!prtd)
320		pr_err("idma_close called with prtd == NULL\n");
321
322	kfree(prtd);
323
324	return 0;
325}
326
327static void idma_free(struct snd_soc_component *component,
328		      struct snd_pcm *pcm)
329{
330	struct snd_pcm_substream *substream;
331	struct snd_dma_buffer *buf;
332
333	substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
334	if (!substream)
335		return;
336
337	buf = &substream->dma_buffer;
338	if (!buf->area)
339		return;
340
341	iounmap((void __iomem *)buf->area);
342
343	buf->area = NULL;
344	buf->addr = 0;
345}
346
347static int preallocate_idma_buffer(struct snd_pcm *pcm, int stream)
348{
349	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
350	struct snd_dma_buffer *buf = &substream->dma_buffer;
351
352	buf->dev.dev = pcm->card->dev;
353	buf->private_data = NULL;
354
355	/* Assign PCM buffer pointers */
356	buf->dev.type = SNDRV_DMA_TYPE_CONTINUOUS;
357	buf->addr = idma.lp_tx_addr;
358	buf->bytes = idma_hardware.buffer_bytes_max;
359	buf->area = (unsigned char * __force)ioremap(buf->addr, buf->bytes);
360	if (!buf->area)
361		return -ENOMEM;
362
363	return 0;
364}
365
366static int idma_new(struct snd_soc_component *component,
367		    struct snd_soc_pcm_runtime *rtd)
368{
369	struct snd_card *card = rtd->card->snd_card;
370	struct snd_pcm *pcm = rtd->pcm;
371	int ret;
372
373	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
374	if (ret)
375		return ret;
376
377	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
378		ret = preallocate_idma_buffer(pcm,
379				SNDRV_PCM_STREAM_PLAYBACK);
380	}
381
382	return ret;
383}
384
385void idma_reg_addr_init(void __iomem *regs, dma_addr_t addr)
386{
387	spin_lock_init(&idma.lock);
388	idma.regs = regs;
389	idma.lp_tx_addr = addr;
390}
391EXPORT_SYMBOL_GPL(idma_reg_addr_init);
392
393static const struct snd_soc_component_driver asoc_idma_platform = {
394	.open		= idma_open,
395	.close		= idma_close,
396	.trigger	= idma_trigger,
397	.pointer	= idma_pointer,
398	.mmap		= idma_mmap,
399	.hw_params	= idma_hw_params,
400	.hw_free	= idma_hw_free,
401	.prepare	= idma_prepare,
402	.pcm_construct	= idma_new,
403	.pcm_destruct	= idma_free,
404};
405
406static int asoc_idma_platform_probe(struct platform_device *pdev)
407{
408	idma_irq = platform_get_irq(pdev, 0);
409	if (idma_irq < 0)
410		return idma_irq;
411
412	return devm_snd_soc_register_component(&pdev->dev, &asoc_idma_platform,
413					       NULL, 0);
414}
415
416static struct platform_driver asoc_idma_driver = {
417	.driver = {
418		.name = "samsung-idma",
419	},
420
421	.probe = asoc_idma_platform_probe,
422};
423
424module_platform_driver(asoc_idma_driver);
425
426MODULE_AUTHOR("Jaswinder Singh, <jassisinghbrar@gmail.com>");
427MODULE_DESCRIPTION("Samsung ASoC IDMA Driver");
428MODULE_LICENSE("GPL");
429