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   1/*
   2 * Copyright (C) 2013-2014 Allwinner Tech Co., Ltd
   3 * Author: Sugar <shuge@allwinnertech.com>
   4 *
   5 * Copyright (C) 2014 Maxime Ripard
   6 * Maxime Ripard <maxime.ripard@free-electrons.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 */
  13
  14#include <linux/clk.h>
  15#include <linux/delay.h>
  16#include <linux/dmaengine.h>
  17#include <linux/dmapool.h>
  18#include <linux/interrupt.h>
  19#include <linux/module.h>
  20#include <linux/of_dma.h>
  21#include <linux/of_device.h>
  22#include <linux/platform_device.h>
  23#include <linux/reset.h>
  24#include <linux/slab.h>
  25#include <linux/types.h>
  26
  27#include "virt-dma.h"
  28
  29/*
  30 * Common registers
  31 */
  32#define DMA_IRQ_EN(x)		((x) * 0x04)
  33#define DMA_IRQ_HALF			BIT(0)
  34#define DMA_IRQ_PKG			BIT(1)
  35#define DMA_IRQ_QUEUE			BIT(2)
  36
  37#define DMA_IRQ_CHAN_NR			8
  38#define DMA_IRQ_CHAN_WIDTH		4
  39
  40
  41#define DMA_IRQ_STAT(x)		((x) * 0x04 + 0x10)
  42
  43#define DMA_STAT		0x30
  44
  45/*
  46 * sun8i specific registers
  47 */
  48#define SUN8I_DMA_GATE		0x20
  49#define SUN8I_DMA_GATE_ENABLE	0x4
  50
  51/*
  52 * Channels specific registers
  53 */
  54#define DMA_CHAN_ENABLE		0x00
  55#define DMA_CHAN_ENABLE_START		BIT(0)
  56#define DMA_CHAN_ENABLE_STOP		0
  57
  58#define DMA_CHAN_PAUSE		0x04
  59#define DMA_CHAN_PAUSE_PAUSE		BIT(1)
  60#define DMA_CHAN_PAUSE_RESUME		0
  61
  62#define DMA_CHAN_LLI_ADDR	0x08
  63
  64#define DMA_CHAN_CUR_CFG	0x0c
  65#define DMA_CHAN_CFG_SRC_DRQ(x)		((x) & 0x1f)
  66#define DMA_CHAN_CFG_SRC_IO_MODE	BIT(5)
  67#define DMA_CHAN_CFG_SRC_LINEAR_MODE	(0 << 5)
  68#define DMA_CHAN_CFG_SRC_BURST(x)	(((x) & 0x3) << 7)
  69#define DMA_CHAN_CFG_SRC_WIDTH(x)	(((x) & 0x3) << 9)
  70
  71#define DMA_CHAN_CFG_DST_DRQ(x)		(DMA_CHAN_CFG_SRC_DRQ(x) << 16)
  72#define DMA_CHAN_CFG_DST_IO_MODE	(DMA_CHAN_CFG_SRC_IO_MODE << 16)
  73#define DMA_CHAN_CFG_DST_LINEAR_MODE	(DMA_CHAN_CFG_SRC_LINEAR_MODE << 16)
  74#define DMA_CHAN_CFG_DST_BURST(x)	(DMA_CHAN_CFG_SRC_BURST(x) << 16)
  75#define DMA_CHAN_CFG_DST_WIDTH(x)	(DMA_CHAN_CFG_SRC_WIDTH(x) << 16)
  76
  77#define DMA_CHAN_CUR_SRC	0x10
  78
  79#define DMA_CHAN_CUR_DST	0x14
  80
  81#define DMA_CHAN_CUR_CNT	0x18
  82
  83#define DMA_CHAN_CUR_PARA	0x1c
  84
  85
  86/*
  87 * Various hardware related defines
  88 */
  89#define LLI_LAST_ITEM	0xfffff800
  90#define NORMAL_WAIT	8
  91#define DRQ_SDRAM	1
  92
  93/*
  94 * Hardware channels / ports representation
  95 *
  96 * The hardware is used in several SoCs, with differing numbers
  97 * of channels and endpoints. This structure ties those numbers
  98 * to a certain compatible string.
  99 */
 100struct sun6i_dma_config {
 101	u32 nr_max_channels;
 102	u32 nr_max_requests;
 103	u32 nr_max_vchans;
 104};
 105
 106/*
 107 * Hardware representation of the LLI
 108 *
 109 * The hardware will be fed the physical address of this structure,
 110 * and read its content in order to start the transfer.
 111 */
 112struct sun6i_dma_lli {
 113	u32			cfg;
 114	u32			src;
 115	u32			dst;
 116	u32			len;
 117	u32			para;
 118	u32			p_lli_next;
 119
 120	/*
 121	 * This field is not used by the DMA controller, but will be
 122	 * used by the CPU to go through the list (mostly for dumping
 123	 * or freeing it).
 124	 */
 125	struct sun6i_dma_lli	*v_lli_next;
 126};
 127
 128
 129struct sun6i_desc {
 130	struct virt_dma_desc	vd;
 131	dma_addr_t		p_lli;
 132	struct sun6i_dma_lli	*v_lli;
 133};
 134
 135struct sun6i_pchan {
 136	u32			idx;
 137	void __iomem		*base;
 138	struct sun6i_vchan	*vchan;
 139	struct sun6i_desc	*desc;
 140	struct sun6i_desc	*done;
 141};
 142
 143struct sun6i_vchan {
 144	struct virt_dma_chan	vc;
 145	struct list_head	node;
 146	struct dma_slave_config	cfg;
 147	struct sun6i_pchan	*phy;
 148	u8			port;
 149};
 150
 151struct sun6i_dma_dev {
 152	struct dma_device	slave;
 153	void __iomem		*base;
 154	struct clk		*clk;
 155	int			irq;
 156	spinlock_t		lock;
 157	struct reset_control	*rstc;
 158	struct tasklet_struct	task;
 159	atomic_t		tasklet_shutdown;
 160	struct list_head	pending;
 161	struct dma_pool		*pool;
 162	struct sun6i_pchan	*pchans;
 163	struct sun6i_vchan	*vchans;
 164	const struct sun6i_dma_config *cfg;
 165};
 166
 167static struct device *chan2dev(struct dma_chan *chan)
 168{
 169	return &chan->dev->device;
 170}
 171
 172static inline struct sun6i_dma_dev *to_sun6i_dma_dev(struct dma_device *d)
 173{
 174	return container_of(d, struct sun6i_dma_dev, slave);
 175}
 176
 177static inline struct sun6i_vchan *to_sun6i_vchan(struct dma_chan *chan)
 178{
 179	return container_of(chan, struct sun6i_vchan, vc.chan);
 180}
 181
 182static inline struct sun6i_desc *
 183to_sun6i_desc(struct dma_async_tx_descriptor *tx)
 184{
 185	return container_of(tx, struct sun6i_desc, vd.tx);
 186}
 187
 188static inline void sun6i_dma_dump_com_regs(struct sun6i_dma_dev *sdev)
 189{
 190	dev_dbg(sdev->slave.dev, "Common register:\n"
 191		"\tmask0(%04x): 0x%08x\n"
 192		"\tmask1(%04x): 0x%08x\n"
 193		"\tpend0(%04x): 0x%08x\n"
 194		"\tpend1(%04x): 0x%08x\n"
 195		"\tstats(%04x): 0x%08x\n",
 196		DMA_IRQ_EN(0), readl(sdev->base + DMA_IRQ_EN(0)),
 197		DMA_IRQ_EN(1), readl(sdev->base + DMA_IRQ_EN(1)),
 198		DMA_IRQ_STAT(0), readl(sdev->base + DMA_IRQ_STAT(0)),
 199		DMA_IRQ_STAT(1), readl(sdev->base + DMA_IRQ_STAT(1)),
 200		DMA_STAT, readl(sdev->base + DMA_STAT));
 201}
 202
 203static inline void sun6i_dma_dump_chan_regs(struct sun6i_dma_dev *sdev,
 204					    struct sun6i_pchan *pchan)
 205{
 206	phys_addr_t reg = virt_to_phys(pchan->base);
 207
 208	dev_dbg(sdev->slave.dev, "Chan %d reg: %pa\n"
 209		"\t___en(%04x): \t0x%08x\n"
 210		"\tpause(%04x): \t0x%08x\n"
 211		"\tstart(%04x): \t0x%08x\n"
 212		"\t__cfg(%04x): \t0x%08x\n"
 213		"\t__src(%04x): \t0x%08x\n"
 214		"\t__dst(%04x): \t0x%08x\n"
 215		"\tcount(%04x): \t0x%08x\n"
 216		"\t_para(%04x): \t0x%08x\n\n",
 217		pchan->idx, &reg,
 218		DMA_CHAN_ENABLE,
 219		readl(pchan->base + DMA_CHAN_ENABLE),
 220		DMA_CHAN_PAUSE,
 221		readl(pchan->base + DMA_CHAN_PAUSE),
 222		DMA_CHAN_LLI_ADDR,
 223		readl(pchan->base + DMA_CHAN_LLI_ADDR),
 224		DMA_CHAN_CUR_CFG,
 225		readl(pchan->base + DMA_CHAN_CUR_CFG),
 226		DMA_CHAN_CUR_SRC,
 227		readl(pchan->base + DMA_CHAN_CUR_SRC),
 228		DMA_CHAN_CUR_DST,
 229		readl(pchan->base + DMA_CHAN_CUR_DST),
 230		DMA_CHAN_CUR_CNT,
 231		readl(pchan->base + DMA_CHAN_CUR_CNT),
 232		DMA_CHAN_CUR_PARA,
 233		readl(pchan->base + DMA_CHAN_CUR_PARA));
 234}
 235
 236static inline s8 convert_burst(u32 maxburst)
 237{
 238	switch (maxburst) {
 239	case 1:
 240		return 0;
 241	case 8:
 242		return 2;
 243	default:
 244		return -EINVAL;
 245	}
 246}
 247
 248static inline s8 convert_buswidth(enum dma_slave_buswidth addr_width)
 249{
 250	if ((addr_width < DMA_SLAVE_BUSWIDTH_1_BYTE) ||
 251	    (addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES))
 252		return -EINVAL;
 253
 254	return addr_width >> 1;
 255}
 256
 257static void *sun6i_dma_lli_add(struct sun6i_dma_lli *prev,
 258			       struct sun6i_dma_lli *next,
 259			       dma_addr_t next_phy,
 260			       struct sun6i_desc *txd)
 261{
 262	if ((!prev && !txd) || !next)
 263		return NULL;
 264
 265	if (!prev) {
 266		txd->p_lli = next_phy;
 267		txd->v_lli = next;
 268	} else {
 269		prev->p_lli_next = next_phy;
 270		prev->v_lli_next = next;
 271	}
 272
 273	next->p_lli_next = LLI_LAST_ITEM;
 274	next->v_lli_next = NULL;
 275
 276	return next;
 277}
 278
 279static inline int sun6i_dma_cfg_lli(struct sun6i_dma_lli *lli,
 280				    dma_addr_t src,
 281				    dma_addr_t dst, u32 len,
 282				    struct dma_slave_config *config)
 283{
 284	u8 src_width, dst_width, src_burst, dst_burst;
 285
 286	if (!config)
 287		return -EINVAL;
 288
 289	src_burst = convert_burst(config->src_maxburst);
 290	if (src_burst)
 291		return src_burst;
 292
 293	dst_burst = convert_burst(config->dst_maxburst);
 294	if (dst_burst)
 295		return dst_burst;
 296
 297	src_width = convert_buswidth(config->src_addr_width);
 298	if (src_width)
 299		return src_width;
 300
 301	dst_width = convert_buswidth(config->dst_addr_width);
 302	if (dst_width)
 303		return dst_width;
 304
 305	lli->cfg = DMA_CHAN_CFG_SRC_BURST(src_burst) |
 306		DMA_CHAN_CFG_SRC_WIDTH(src_width) |
 307		DMA_CHAN_CFG_DST_BURST(dst_burst) |
 308		DMA_CHAN_CFG_DST_WIDTH(dst_width);
 309
 310	lli->src = src;
 311	lli->dst = dst;
 312	lli->len = len;
 313	lli->para = NORMAL_WAIT;
 314
 315	return 0;
 316}
 317
 318static inline void sun6i_dma_dump_lli(struct sun6i_vchan *vchan,
 319				      struct sun6i_dma_lli *lli)
 320{
 321	phys_addr_t p_lli = virt_to_phys(lli);
 322
 323	dev_dbg(chan2dev(&vchan->vc.chan),
 324		"\n\tdesc:   p - %pa v - 0x%p\n"
 325		"\t\tc - 0x%08x s - 0x%08x d - 0x%08x\n"
 326		"\t\tl - 0x%08x p - 0x%08x n - 0x%08x\n",
 327		&p_lli, lli,
 328		lli->cfg, lli->src, lli->dst,
 329		lli->len, lli->para, lli->p_lli_next);
 330}
 331
 332static void sun6i_dma_free_desc(struct virt_dma_desc *vd)
 333{
 334	struct sun6i_desc *txd = to_sun6i_desc(&vd->tx);
 335	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vd->tx.chan->device);
 336	struct sun6i_dma_lli *v_lli, *v_next;
 337	dma_addr_t p_lli, p_next;
 338
 339	if (unlikely(!txd))
 340		return;
 341
 342	p_lli = txd->p_lli;
 343	v_lli = txd->v_lli;
 344
 345	while (v_lli) {
 346		v_next = v_lli->v_lli_next;
 347		p_next = v_lli->p_lli_next;
 348
 349		dma_pool_free(sdev->pool, v_lli, p_lli);
 350
 351		v_lli = v_next;
 352		p_lli = p_next;
 353	}
 354
 355	kfree(txd);
 356}
 357
 358static int sun6i_dma_start_desc(struct sun6i_vchan *vchan)
 359{
 360	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(vchan->vc.chan.device);
 361	struct virt_dma_desc *desc = vchan_next_desc(&vchan->vc);
 362	struct sun6i_pchan *pchan = vchan->phy;
 363	u32 irq_val, irq_reg, irq_offset;
 364
 365	if (!pchan)
 366		return -EAGAIN;
 367
 368	if (!desc) {
 369		pchan->desc = NULL;
 370		pchan->done = NULL;
 371		return -EAGAIN;
 372	}
 373
 374	list_del(&desc->node);
 375
 376	pchan->desc = to_sun6i_desc(&desc->tx);
 377	pchan->done = NULL;
 378
 379	sun6i_dma_dump_lli(vchan, pchan->desc->v_lli);
 380
 381	irq_reg = pchan->idx / DMA_IRQ_CHAN_NR;
 382	irq_offset = pchan->idx % DMA_IRQ_CHAN_NR;
 383
 384	irq_val = readl(sdev->base + DMA_IRQ_EN(irq_offset));
 385	irq_val |= DMA_IRQ_QUEUE << (irq_offset * DMA_IRQ_CHAN_WIDTH);
 386	writel(irq_val, sdev->base + DMA_IRQ_EN(irq_offset));
 387
 388	writel(pchan->desc->p_lli, pchan->base + DMA_CHAN_LLI_ADDR);
 389	writel(DMA_CHAN_ENABLE_START, pchan->base + DMA_CHAN_ENABLE);
 390
 391	sun6i_dma_dump_com_regs(sdev);
 392	sun6i_dma_dump_chan_regs(sdev, pchan);
 393
 394	return 0;
 395}
 396
 397static void sun6i_dma_tasklet(unsigned long data)
 398{
 399	struct sun6i_dma_dev *sdev = (struct sun6i_dma_dev *)data;
 400	const struct sun6i_dma_config *cfg = sdev->cfg;
 401	struct sun6i_vchan *vchan;
 402	struct sun6i_pchan *pchan;
 403	unsigned int pchan_alloc = 0;
 404	unsigned int pchan_idx;
 405
 406	list_for_each_entry(vchan, &sdev->slave.channels, vc.chan.device_node) {
 407		spin_lock_irq(&vchan->vc.lock);
 408
 409		pchan = vchan->phy;
 410
 411		if (pchan && pchan->done) {
 412			if (sun6i_dma_start_desc(vchan)) {
 413				/*
 414				 * No current txd associated with this channel
 415				 */
 416				dev_dbg(sdev->slave.dev, "pchan %u: free\n",
 417					pchan->idx);
 418
 419				/* Mark this channel free */
 420				vchan->phy = NULL;
 421				pchan->vchan = NULL;
 422			}
 423		}
 424		spin_unlock_irq(&vchan->vc.lock);
 425	}
 426
 427	spin_lock_irq(&sdev->lock);
 428	for (pchan_idx = 0; pchan_idx < cfg->nr_max_channels; pchan_idx++) {
 429		pchan = &sdev->pchans[pchan_idx];
 430
 431		if (pchan->vchan || list_empty(&sdev->pending))
 432			continue;
 433
 434		vchan = list_first_entry(&sdev->pending,
 435					 struct sun6i_vchan, node);
 436
 437		/* Remove from pending channels */
 438		list_del_init(&vchan->node);
 439		pchan_alloc |= BIT(pchan_idx);
 440
 441		/* Mark this channel allocated */
 442		pchan->vchan = vchan;
 443		vchan->phy = pchan;
 444		dev_dbg(sdev->slave.dev, "pchan %u: alloc vchan %p\n",
 445			pchan->idx, &vchan->vc);
 446	}
 447	spin_unlock_irq(&sdev->lock);
 448
 449	for (pchan_idx = 0; pchan_idx < cfg->nr_max_channels; pchan_idx++) {
 450		if (!(pchan_alloc & BIT(pchan_idx)))
 451			continue;
 452
 453		pchan = sdev->pchans + pchan_idx;
 454		vchan = pchan->vchan;
 455		if (vchan) {
 456			spin_lock_irq(&vchan->vc.lock);
 457			sun6i_dma_start_desc(vchan);
 458			spin_unlock_irq(&vchan->vc.lock);
 459		}
 460	}
 461}
 462
 463static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
 464{
 465	struct sun6i_dma_dev *sdev = dev_id;
 466	struct sun6i_vchan *vchan;
 467	struct sun6i_pchan *pchan;
 468	int i, j, ret = IRQ_NONE;
 469	u32 status;
 470
 471	for (i = 0; i < sdev->cfg->nr_max_channels / DMA_IRQ_CHAN_NR; i++) {
 472		status = readl(sdev->base + DMA_IRQ_STAT(i));
 473		if (!status)
 474			continue;
 475
 476		dev_dbg(sdev->slave.dev, "DMA irq status %s: 0x%x\n",
 477			i ? "high" : "low", status);
 478
 479		writel(status, sdev->base + DMA_IRQ_STAT(i));
 480
 481		for (j = 0; (j < DMA_IRQ_CHAN_NR) && status; j++) {
 482			if (status & DMA_IRQ_QUEUE) {
 483				pchan = sdev->pchans + j;
 484				vchan = pchan->vchan;
 485
 486				if (vchan) {
 487					spin_lock(&vchan->vc.lock);
 488					vchan_cookie_complete(&pchan->desc->vd);
 489					pchan->done = pchan->desc;
 490					spin_unlock(&vchan->vc.lock);
 491				}
 492			}
 493
 494			status = status >> DMA_IRQ_CHAN_WIDTH;
 495		}
 496
 497		if (!atomic_read(&sdev->tasklet_shutdown))
 498			tasklet_schedule(&sdev->task);
 499		ret = IRQ_HANDLED;
 500	}
 501
 502	return ret;
 503}
 504
 505static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy(
 506		struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 507		size_t len, unsigned long flags)
 508{
 509	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 510	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 511	struct sun6i_dma_lli *v_lli;
 512	struct sun6i_desc *txd;
 513	dma_addr_t p_lli;
 514	s8 burst, width;
 515
 516	dev_dbg(chan2dev(chan),
 517		"%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n",
 518		__func__, vchan->vc.chan.chan_id, &dest, &src, len, flags);
 519
 520	if (!len)
 521		return NULL;
 522
 523	txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
 524	if (!txd)
 525		return NULL;
 526
 527	v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
 528	if (!v_lli) {
 529		dev_err(sdev->slave.dev, "Failed to alloc lli memory\n");
 530		goto err_txd_free;
 531	}
 532
 533	v_lli->src = src;
 534	v_lli->dst = dest;
 535	v_lli->len = len;
 536	v_lli->para = NORMAL_WAIT;
 537
 538	burst = convert_burst(8);
 539	width = convert_buswidth(DMA_SLAVE_BUSWIDTH_4_BYTES);
 540	v_lli->cfg |= DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
 541		DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
 542		DMA_CHAN_CFG_DST_LINEAR_MODE |
 543		DMA_CHAN_CFG_SRC_LINEAR_MODE |
 544		DMA_CHAN_CFG_SRC_BURST(burst) |
 545		DMA_CHAN_CFG_SRC_WIDTH(width) |
 546		DMA_CHAN_CFG_DST_BURST(burst) |
 547		DMA_CHAN_CFG_DST_WIDTH(width);
 548
 549	sun6i_dma_lli_add(NULL, v_lli, p_lli, txd);
 550
 551	sun6i_dma_dump_lli(vchan, v_lli);
 552
 553	return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
 554
 555err_txd_free:
 556	kfree(txd);
 557	return NULL;
 558}
 559
 560static struct dma_async_tx_descriptor *sun6i_dma_prep_slave_sg(
 561		struct dma_chan *chan, struct scatterlist *sgl,
 562		unsigned int sg_len, enum dma_transfer_direction dir,
 563		unsigned long flags, void *context)
 564{
 565	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 566	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 567	struct dma_slave_config *sconfig = &vchan->cfg;
 568	struct sun6i_dma_lli *v_lli, *prev = NULL;
 569	struct sun6i_desc *txd;
 570	struct scatterlist *sg;
 571	dma_addr_t p_lli;
 572	int i, ret;
 573
 574	if (!sgl)
 575		return NULL;
 576
 577	if (!is_slave_direction(dir)) {
 578		dev_err(chan2dev(chan), "Invalid DMA direction\n");
 579		return NULL;
 580	}
 581
 582	txd = kzalloc(sizeof(*txd), GFP_NOWAIT);
 583	if (!txd)
 584		return NULL;
 585
 586	for_each_sg(sgl, sg, sg_len, i) {
 587		v_lli = dma_pool_alloc(sdev->pool, GFP_NOWAIT, &p_lli);
 588		if (!v_lli)
 589			goto err_lli_free;
 590
 591		if (dir == DMA_MEM_TO_DEV) {
 592			ret = sun6i_dma_cfg_lli(v_lli, sg_dma_address(sg),
 593						sconfig->dst_addr, sg_dma_len(sg),
 594						sconfig);
 595			if (ret)
 596				goto err_cur_lli_free;
 597
 598			v_lli->cfg |= DMA_CHAN_CFG_DST_IO_MODE |
 599				DMA_CHAN_CFG_SRC_LINEAR_MODE |
 600				DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) |
 601				DMA_CHAN_CFG_DST_DRQ(vchan->port);
 602
 603			dev_dbg(chan2dev(chan),
 604				"%s; chan: %d, dest: %pad, src: %pad, len: %u. flags: 0x%08lx\n",
 605				__func__, vchan->vc.chan.chan_id,
 606				&sconfig->dst_addr, &sg_dma_address(sg),
 607				sg_dma_len(sg), flags);
 608
 609		} else {
 610			ret = sun6i_dma_cfg_lli(v_lli, sconfig->src_addr,
 611						sg_dma_address(sg), sg_dma_len(sg),
 612						sconfig);
 613			if (ret)
 614				goto err_cur_lli_free;
 615
 616			v_lli->cfg |= DMA_CHAN_CFG_DST_LINEAR_MODE |
 617				DMA_CHAN_CFG_SRC_IO_MODE |
 618				DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) |
 619				DMA_CHAN_CFG_SRC_DRQ(vchan->port);
 620
 621			dev_dbg(chan2dev(chan),
 622				"%s; chan: %d, dest: %pad, src: %pad, len: %u. flags: 0x%08lx\n",
 623				__func__, vchan->vc.chan.chan_id,
 624				&sg_dma_address(sg), &sconfig->src_addr,
 625				sg_dma_len(sg), flags);
 626		}
 627
 628		prev = sun6i_dma_lli_add(prev, v_lli, p_lli, txd);
 629	}
 630
 631	dev_dbg(chan2dev(chan), "First: %pad\n", &txd->p_lli);
 632	for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
 633		sun6i_dma_dump_lli(vchan, prev);
 634
 635	return vchan_tx_prep(&vchan->vc, &txd->vd, flags);
 636
 637err_cur_lli_free:
 638	dma_pool_free(sdev->pool, v_lli, p_lli);
 639err_lli_free:
 640	for (prev = txd->v_lli; prev; prev = prev->v_lli_next)
 641		dma_pool_free(sdev->pool, prev, virt_to_phys(prev));
 642	kfree(txd);
 643	return NULL;
 644}
 645
 646static int sun6i_dma_config(struct dma_chan *chan,
 647			    struct dma_slave_config *config)
 648{
 649	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 650
 651	memcpy(&vchan->cfg, config, sizeof(*config));
 652
 653	return 0;
 654}
 655
 656static int sun6i_dma_pause(struct dma_chan *chan)
 657{
 658	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 659	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 660	struct sun6i_pchan *pchan = vchan->phy;
 661
 662	dev_dbg(chan2dev(chan), "vchan %p: pause\n", &vchan->vc);
 663
 664	if (pchan) {
 665		writel(DMA_CHAN_PAUSE_PAUSE,
 666		       pchan->base + DMA_CHAN_PAUSE);
 667	} else {
 668		spin_lock(&sdev->lock);
 669		list_del_init(&vchan->node);
 670		spin_unlock(&sdev->lock);
 671	}
 672
 673	return 0;
 674}
 675
 676static int sun6i_dma_resume(struct dma_chan *chan)
 677{
 678	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 679	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 680	struct sun6i_pchan *pchan = vchan->phy;
 681	unsigned long flags;
 682
 683	dev_dbg(chan2dev(chan), "vchan %p: resume\n", &vchan->vc);
 684
 685	spin_lock_irqsave(&vchan->vc.lock, flags);
 686
 687	if (pchan) {
 688		writel(DMA_CHAN_PAUSE_RESUME,
 689		       pchan->base + DMA_CHAN_PAUSE);
 690	} else if (!list_empty(&vchan->vc.desc_issued)) {
 691		spin_lock(&sdev->lock);
 692		list_add_tail(&vchan->node, &sdev->pending);
 693		spin_unlock(&sdev->lock);
 694	}
 695
 696	spin_unlock_irqrestore(&vchan->vc.lock, flags);
 697
 698	return 0;
 699}
 700
 701static int sun6i_dma_terminate_all(struct dma_chan *chan)
 702{
 703	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 704	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 705	struct sun6i_pchan *pchan = vchan->phy;
 706	unsigned long flags;
 707	LIST_HEAD(head);
 708
 709	spin_lock(&sdev->lock);
 710	list_del_init(&vchan->node);
 711	spin_unlock(&sdev->lock);
 712
 713	spin_lock_irqsave(&vchan->vc.lock, flags);
 714
 715	vchan_get_all_descriptors(&vchan->vc, &head);
 716
 717	if (pchan) {
 718		writel(DMA_CHAN_ENABLE_STOP, pchan->base + DMA_CHAN_ENABLE);
 719		writel(DMA_CHAN_PAUSE_RESUME, pchan->base + DMA_CHAN_PAUSE);
 720
 721		vchan->phy = NULL;
 722		pchan->vchan = NULL;
 723		pchan->desc = NULL;
 724		pchan->done = NULL;
 725	}
 726
 727	spin_unlock_irqrestore(&vchan->vc.lock, flags);
 728
 729	vchan_dma_desc_free_list(&vchan->vc, &head);
 730
 731	return 0;
 732}
 733
 734static enum dma_status sun6i_dma_tx_status(struct dma_chan *chan,
 735					   dma_cookie_t cookie,
 736					   struct dma_tx_state *state)
 737{
 738	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 739	struct sun6i_pchan *pchan = vchan->phy;
 740	struct sun6i_dma_lli *lli;
 741	struct virt_dma_desc *vd;
 742	struct sun6i_desc *txd;
 743	enum dma_status ret;
 744	unsigned long flags;
 745	size_t bytes = 0;
 746
 747	ret = dma_cookie_status(chan, cookie, state);
 748	if (ret == DMA_COMPLETE)
 749		return ret;
 750
 751	spin_lock_irqsave(&vchan->vc.lock, flags);
 752
 753	vd = vchan_find_desc(&vchan->vc, cookie);
 754	txd = to_sun6i_desc(&vd->tx);
 755
 756	if (vd) {
 757		for (lli = txd->v_lli; lli != NULL; lli = lli->v_lli_next)
 758			bytes += lli->len;
 759	} else if (!pchan || !pchan->desc) {
 760		bytes = 0;
 761	} else {
 762		bytes = readl(pchan->base + DMA_CHAN_CUR_CNT);
 763	}
 764
 765	spin_unlock_irqrestore(&vchan->vc.lock, flags);
 766
 767	dma_set_residue(state, bytes);
 768
 769	return ret;
 770}
 771
 772static void sun6i_dma_issue_pending(struct dma_chan *chan)
 773{
 774	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 775	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 776	unsigned long flags;
 777
 778	spin_lock_irqsave(&vchan->vc.lock, flags);
 779
 780	if (vchan_issue_pending(&vchan->vc)) {
 781		spin_lock(&sdev->lock);
 782
 783		if (!vchan->phy && list_empty(&vchan->node)) {
 784			list_add_tail(&vchan->node, &sdev->pending);
 785			tasklet_schedule(&sdev->task);
 786			dev_dbg(chan2dev(chan), "vchan %p: issued\n",
 787				&vchan->vc);
 788		}
 789
 790		spin_unlock(&sdev->lock);
 791	} else {
 792		dev_dbg(chan2dev(chan), "vchan %p: nothing to issue\n",
 793			&vchan->vc);
 794	}
 795
 796	spin_unlock_irqrestore(&vchan->vc.lock, flags);
 797}
 798
 799static void sun6i_dma_free_chan_resources(struct dma_chan *chan)
 800{
 801	struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device);
 802	struct sun6i_vchan *vchan = to_sun6i_vchan(chan);
 803	unsigned long flags;
 804
 805	spin_lock_irqsave(&sdev->lock, flags);
 806	list_del_init(&vchan->node);
 807	spin_unlock_irqrestore(&sdev->lock, flags);
 808
 809	vchan_free_chan_resources(&vchan->vc);
 810}
 811
 812static struct dma_chan *sun6i_dma_of_xlate(struct of_phandle_args *dma_spec,
 813					   struct of_dma *ofdma)
 814{
 815	struct sun6i_dma_dev *sdev = ofdma->of_dma_data;
 816	struct sun6i_vchan *vchan;
 817	struct dma_chan *chan;
 818	u8 port = dma_spec->args[0];
 819
 820	if (port > sdev->cfg->nr_max_requests)
 821		return NULL;
 822
 823	chan = dma_get_any_slave_channel(&sdev->slave);
 824	if (!chan)
 825		return NULL;
 826
 827	vchan = to_sun6i_vchan(chan);
 828	vchan->port = port;
 829
 830	return chan;
 831}
 832
 833static inline void sun6i_kill_tasklet(struct sun6i_dma_dev *sdev)
 834{
 835	/* Disable all interrupts from DMA */
 836	writel(0, sdev->base + DMA_IRQ_EN(0));
 837	writel(0, sdev->base + DMA_IRQ_EN(1));
 838
 839	/* Prevent spurious interrupts from scheduling the tasklet */
 840	atomic_inc(&sdev->tasklet_shutdown);
 841
 842	/* Make sure we won't have any further interrupts */
 843	devm_free_irq(sdev->slave.dev, sdev->irq, sdev);
 844
 845	/* Actually prevent the tasklet from being scheduled */
 846	tasklet_kill(&sdev->task);
 847}
 848
 849static inline void sun6i_dma_free(struct sun6i_dma_dev *sdev)
 850{
 851	int i;
 852
 853	for (i = 0; i < sdev->cfg->nr_max_vchans; i++) {
 854		struct sun6i_vchan *vchan = &sdev->vchans[i];
 855
 856		list_del(&vchan->vc.chan.device_node);
 857		tasklet_kill(&vchan->vc.task);
 858	}
 859}
 860
 861/*
 862 * For A31:
 863 *
 864 * There's 16 physical channels that can work in parallel.
 865 *
 866 * However we have 30 different endpoints for our requests.
 867 *
 868 * Since the channels are able to handle only an unidirectional
 869 * transfer, we need to allocate more virtual channels so that
 870 * everyone can grab one channel.
 871 *
 872 * Some devices can't work in both direction (mostly because it
 873 * wouldn't make sense), so we have a bit fewer virtual channels than
 874 * 2 channels per endpoints.
 875 */
 876
 877static struct sun6i_dma_config sun6i_a31_dma_cfg = {
 878	.nr_max_channels = 16,
 879	.nr_max_requests = 30,
 880	.nr_max_vchans   = 53,
 881};
 882
 883/*
 884 * The A23 only has 8 physical channels, a maximum DRQ port id of 24,
 885 * and a total of 37 usable source and destination endpoints.
 886 */
 887
 888static struct sun6i_dma_config sun8i_a23_dma_cfg = {
 889	.nr_max_channels = 8,
 890	.nr_max_requests = 24,
 891	.nr_max_vchans   = 37,
 892};
 893
 894/*
 895 * The H3 has 12 physical channels, a maximum DRQ port id of 27,
 896 * and a total of 34 usable source and destination endpoints.
 897 */
 898
 899static struct sun6i_dma_config sun8i_h3_dma_cfg = {
 900	.nr_max_channels = 12,
 901	.nr_max_requests = 27,
 902	.nr_max_vchans   = 34,
 903};
 904
 905static const struct of_device_id sun6i_dma_match[] = {
 906	{ .compatible = "allwinner,sun6i-a31-dma", .data = &sun6i_a31_dma_cfg },
 907	{ .compatible = "allwinner,sun8i-a23-dma", .data = &sun8i_a23_dma_cfg },
 908	{ .compatible = "allwinner,sun8i-h3-dma", .data = &sun8i_h3_dma_cfg },
 909	{ /* sentinel */ }
 910};
 911MODULE_DEVICE_TABLE(of, sun6i_dma_match);
 912
 913static int sun6i_dma_probe(struct platform_device *pdev)
 914{
 915	const struct of_device_id *device;
 916	struct sun6i_dma_dev *sdc;
 917	struct resource *res;
 918	int ret, i;
 919
 920	sdc = devm_kzalloc(&pdev->dev, sizeof(*sdc), GFP_KERNEL);
 921	if (!sdc)
 922		return -ENOMEM;
 923
 924	device = of_match_device(sun6i_dma_match, &pdev->dev);
 925	if (!device)
 926		return -ENODEV;
 927	sdc->cfg = device->data;
 928
 929	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 930	sdc->base = devm_ioremap_resource(&pdev->dev, res);
 931	if (IS_ERR(sdc->base))
 932		return PTR_ERR(sdc->base);
 933
 934	sdc->irq = platform_get_irq(pdev, 0);
 935	if (sdc->irq < 0) {
 936		dev_err(&pdev->dev, "Cannot claim IRQ\n");
 937		return sdc->irq;
 938	}
 939
 940	sdc->clk = devm_clk_get(&pdev->dev, NULL);
 941	if (IS_ERR(sdc->clk)) {
 942		dev_err(&pdev->dev, "No clock specified\n");
 943		return PTR_ERR(sdc->clk);
 944	}
 945
 946	sdc->rstc = devm_reset_control_get(&pdev->dev, NULL);
 947	if (IS_ERR(sdc->rstc)) {
 948		dev_err(&pdev->dev, "No reset controller specified\n");
 949		return PTR_ERR(sdc->rstc);
 950	}
 951
 952	sdc->pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
 953				     sizeof(struct sun6i_dma_lli), 4, 0);
 954	if (!sdc->pool) {
 955		dev_err(&pdev->dev, "No memory for descriptors dma pool\n");
 956		return -ENOMEM;
 957	}
 958
 959	platform_set_drvdata(pdev, sdc);
 960	INIT_LIST_HEAD(&sdc->pending);
 961	spin_lock_init(&sdc->lock);
 962
 963	dma_cap_set(DMA_PRIVATE, sdc->slave.cap_mask);
 964	dma_cap_set(DMA_MEMCPY, sdc->slave.cap_mask);
 965	dma_cap_set(DMA_SLAVE, sdc->slave.cap_mask);
 966
 967	INIT_LIST_HEAD(&sdc->slave.channels);
 968	sdc->slave.device_free_chan_resources	= sun6i_dma_free_chan_resources;
 969	sdc->slave.device_tx_status		= sun6i_dma_tx_status;
 970	sdc->slave.device_issue_pending		= sun6i_dma_issue_pending;
 971	sdc->slave.device_prep_slave_sg		= sun6i_dma_prep_slave_sg;
 972	sdc->slave.device_prep_dma_memcpy	= sun6i_dma_prep_dma_memcpy;
 973	sdc->slave.copy_align			= DMAENGINE_ALIGN_4_BYTES;
 974	sdc->slave.device_config		= sun6i_dma_config;
 975	sdc->slave.device_pause			= sun6i_dma_pause;
 976	sdc->slave.device_resume		= sun6i_dma_resume;
 977	sdc->slave.device_terminate_all		= sun6i_dma_terminate_all;
 978	sdc->slave.src_addr_widths		= BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
 979						  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
 980						  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 981	sdc->slave.dst_addr_widths		= BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
 982						  BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
 983						  BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
 984	sdc->slave.directions			= BIT(DMA_DEV_TO_MEM) |
 985						  BIT(DMA_MEM_TO_DEV);
 986	sdc->slave.residue_granularity		= DMA_RESIDUE_GRANULARITY_BURST;
 987	sdc->slave.dev = &pdev->dev;
 988
 989	sdc->pchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_channels,
 990				   sizeof(struct sun6i_pchan), GFP_KERNEL);
 991	if (!sdc->pchans)
 992		return -ENOMEM;
 993
 994	sdc->vchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_vchans,
 995				   sizeof(struct sun6i_vchan), GFP_KERNEL);
 996	if (!sdc->vchans)
 997		return -ENOMEM;
 998
 999	tasklet_init(&sdc->task, sun6i_dma_tasklet, (unsigned long)sdc);
1000
1001	for (i = 0; i < sdc->cfg->nr_max_channels; i++) {
1002		struct sun6i_pchan *pchan = &sdc->pchans[i];
1003
1004		pchan->idx = i;
1005		pchan->base = sdc->base + 0x100 + i * 0x40;
1006	}
1007
1008	for (i = 0; i < sdc->cfg->nr_max_vchans; i++) {
1009		struct sun6i_vchan *vchan = &sdc->vchans[i];
1010
1011		INIT_LIST_HEAD(&vchan->node);
1012		vchan->vc.desc_free = sun6i_dma_free_desc;
1013		vchan_init(&vchan->vc, &sdc->slave);
1014	}
1015
1016	ret = reset_control_deassert(sdc->rstc);
1017	if (ret) {
1018		dev_err(&pdev->dev, "Couldn't deassert the device from reset\n");
1019		goto err_chan_free;
1020	}
1021
1022	ret = clk_prepare_enable(sdc->clk);
1023	if (ret) {
1024		dev_err(&pdev->dev, "Couldn't enable the clock\n");
1025		goto err_reset_assert;
1026	}
1027
1028	ret = devm_request_irq(&pdev->dev, sdc->irq, sun6i_dma_interrupt, 0,
1029			       dev_name(&pdev->dev), sdc);
1030	if (ret) {
1031		dev_err(&pdev->dev, "Cannot request IRQ\n");
1032		goto err_clk_disable;
1033	}
1034
1035	ret = dma_async_device_register(&sdc->slave);
1036	if (ret) {
1037		dev_warn(&pdev->dev, "Failed to register DMA engine device\n");
1038		goto err_irq_disable;
1039	}
1040
1041	ret = of_dma_controller_register(pdev->dev.of_node, sun6i_dma_of_xlate,
1042					 sdc);
1043	if (ret) {
1044		dev_err(&pdev->dev, "of_dma_controller_register failed\n");
1045		goto err_dma_unregister;
1046	}
1047
1048	/*
1049	 * sun8i variant requires us to toggle a dma gating register,
1050	 * as seen in Allwinner's SDK. This register is not documented
1051	 * in the A23 user manual.
1052	 */
1053	if (of_device_is_compatible(pdev->dev.of_node,
1054				    "allwinner,sun8i-a23-dma"))
1055		writel(SUN8I_DMA_GATE_ENABLE, sdc->base + SUN8I_DMA_GATE);
1056
1057	return 0;
1058
1059err_dma_unregister:
1060	dma_async_device_unregister(&sdc->slave);
1061err_irq_disable:
1062	sun6i_kill_tasklet(sdc);
1063err_clk_disable:
1064	clk_disable_unprepare(sdc->clk);
1065err_reset_assert:
1066	reset_control_assert(sdc->rstc);
1067err_chan_free:
1068	sun6i_dma_free(sdc);
1069	return ret;
1070}
1071
1072static int sun6i_dma_remove(struct platform_device *pdev)
1073{
1074	struct sun6i_dma_dev *sdc = platform_get_drvdata(pdev);
1075
1076	of_dma_controller_free(pdev->dev.of_node);
1077	dma_async_device_unregister(&sdc->slave);
1078
1079	sun6i_kill_tasklet(sdc);
1080
1081	clk_disable_unprepare(sdc->clk);
1082	reset_control_assert(sdc->rstc);
1083
1084	sun6i_dma_free(sdc);
1085
1086	return 0;
1087}
1088
1089static struct platform_driver sun6i_dma_driver = {
1090	.probe		= sun6i_dma_probe,
1091	.remove		= sun6i_dma_remove,
1092	.driver = {
1093		.name		= "sun6i-dma",
1094		.of_match_table	= sun6i_dma_match,
1095	},
1096};
1097module_platform_driver(sun6i_dma_driver);
1098
1099MODULE_DESCRIPTION("Allwinner A31 DMA Controller Driver");
1100MODULE_AUTHOR("Sugar <shuge@allwinnertech.com>");
1101MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
1102MODULE_LICENSE("GPL");