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v5.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * DMA driver for Nvidia's Tegra20 APB DMA controller.
   4 *
   5 * Copyright (c) 2012-2013, NVIDIA CORPORATION.  All rights reserved.
 
 
 
 
 
 
 
 
 
 
 
 
   6 */
   7
   8#include <linux/bitops.h>
   9#include <linux/clk.h>
  10#include <linux/delay.h>
  11#include <linux/dmaengine.h>
  12#include <linux/dma-mapping.h>
  13#include <linux/err.h>
  14#include <linux/init.h>
  15#include <linux/interrupt.h>
  16#include <linux/io.h>
  17#include <linux/mm.h>
  18#include <linux/module.h>
  19#include <linux/of.h>
  20#include <linux/of_device.h>
  21#include <linux/of_dma.h>
  22#include <linux/platform_device.h>
  23#include <linux/pm.h>
  24#include <linux/pm_runtime.h>
  25#include <linux/reset.h>
  26#include <linux/slab.h>
  27
  28#include "dmaengine.h"
  29
  30#define CREATE_TRACE_POINTS
  31#include <trace/events/tegra_apb_dma.h>
  32
  33#define TEGRA_APBDMA_GENERAL			0x0
  34#define TEGRA_APBDMA_GENERAL_ENABLE		BIT(31)
  35
  36#define TEGRA_APBDMA_CONTROL			0x010
  37#define TEGRA_APBDMA_IRQ_MASK			0x01c
  38#define TEGRA_APBDMA_IRQ_MASK_SET		0x020
  39
  40/* CSR register */
  41#define TEGRA_APBDMA_CHAN_CSR			0x00
  42#define TEGRA_APBDMA_CSR_ENB			BIT(31)
  43#define TEGRA_APBDMA_CSR_IE_EOC			BIT(30)
  44#define TEGRA_APBDMA_CSR_HOLD			BIT(29)
  45#define TEGRA_APBDMA_CSR_DIR			BIT(28)
  46#define TEGRA_APBDMA_CSR_ONCE			BIT(27)
  47#define TEGRA_APBDMA_CSR_FLOW			BIT(21)
  48#define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT		16
  49#define TEGRA_APBDMA_CSR_REQ_SEL_MASK		0x1F
  50#define TEGRA_APBDMA_CSR_WCOUNT_MASK		0xFFFC
  51
  52/* STATUS register */
  53#define TEGRA_APBDMA_CHAN_STATUS		0x004
  54#define TEGRA_APBDMA_STATUS_BUSY		BIT(31)
  55#define TEGRA_APBDMA_STATUS_ISE_EOC		BIT(30)
  56#define TEGRA_APBDMA_STATUS_HALT		BIT(29)
  57#define TEGRA_APBDMA_STATUS_PING_PONG		BIT(28)
  58#define TEGRA_APBDMA_STATUS_COUNT_SHIFT		2
  59#define TEGRA_APBDMA_STATUS_COUNT_MASK		0xFFFC
  60
  61#define TEGRA_APBDMA_CHAN_CSRE			0x00C
  62#define TEGRA_APBDMA_CHAN_CSRE_PAUSE		(1 << 31)
  63
  64/* AHB memory address */
  65#define TEGRA_APBDMA_CHAN_AHBPTR		0x010
  66
  67/* AHB sequence register */
  68#define TEGRA_APBDMA_CHAN_AHBSEQ		0x14
  69#define TEGRA_APBDMA_AHBSEQ_INTR_ENB		BIT(31)
  70#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_8		(0 << 28)
  71#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_16	(1 << 28)
  72#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32	(2 << 28)
  73#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_64	(3 << 28)
  74#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_128	(4 << 28)
  75#define TEGRA_APBDMA_AHBSEQ_DATA_SWAP		BIT(27)
  76#define TEGRA_APBDMA_AHBSEQ_BURST_1		(4 << 24)
  77#define TEGRA_APBDMA_AHBSEQ_BURST_4		(5 << 24)
  78#define TEGRA_APBDMA_AHBSEQ_BURST_8		(6 << 24)
  79#define TEGRA_APBDMA_AHBSEQ_DBL_BUF		BIT(19)
  80#define TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT		16
  81#define TEGRA_APBDMA_AHBSEQ_WRAP_NONE		0
  82
  83/* APB address */
  84#define TEGRA_APBDMA_CHAN_APBPTR		0x018
  85
  86/* APB sequence register */
  87#define TEGRA_APBDMA_CHAN_APBSEQ		0x01c
  88#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8		(0 << 28)
  89#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16	(1 << 28)
  90#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32	(2 << 28)
  91#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64	(3 << 28)
  92#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_128	(4 << 28)
  93#define TEGRA_APBDMA_APBSEQ_DATA_SWAP		BIT(27)
  94#define TEGRA_APBDMA_APBSEQ_WRAP_WORD_1		(1 << 16)
  95
  96/* Tegra148 specific registers */
  97#define TEGRA_APBDMA_CHAN_WCOUNT		0x20
  98
  99#define TEGRA_APBDMA_CHAN_WORD_TRANSFER		0x24
 100
 101/*
 102 * If any burst is in flight and DMA paused then this is the time to complete
 103 * on-flight burst and update DMA status register.
 104 */
 105#define TEGRA_APBDMA_BURST_COMPLETE_TIME	20
 106
 107/* Channel base address offset from APBDMA base address */
 108#define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET	0x1000
 109
 110#define TEGRA_APBDMA_SLAVE_ID_INVALID	(TEGRA_APBDMA_CSR_REQ_SEL_MASK + 1)
 111
 112struct tegra_dma;
 113
 114/*
 115 * tegra_dma_chip_data Tegra chip specific DMA data
 116 * @nr_channels: Number of channels available in the controller.
 117 * @channel_reg_size: Channel register size/stride.
 118 * @max_dma_count: Maximum DMA transfer count supported by DMA controller.
 119 * @support_channel_pause: Support channel wise pause of dma.
 120 * @support_separate_wcount_reg: Support separate word count register.
 121 */
 122struct tegra_dma_chip_data {
 123	int nr_channels;
 124	int channel_reg_size;
 125	int max_dma_count;
 126	bool support_channel_pause;
 127	bool support_separate_wcount_reg;
 128};
 129
 130/* DMA channel registers */
 131struct tegra_dma_channel_regs {
 132	unsigned long	csr;
 133	unsigned long	ahb_ptr;
 134	unsigned long	apb_ptr;
 135	unsigned long	ahb_seq;
 136	unsigned long	apb_seq;
 137	unsigned long	wcount;
 138};
 139
 140/*
 141 * tegra_dma_sg_req: DMA request details to configure hardware. This
 142 * contains the details for one transfer to configure DMA hw.
 143 * The client's request for data transfer can be broken into multiple
 144 * sub-transfer as per requester details and hw support.
 145 * This sub transfer get added in the list of transfer and point to Tegra
 146 * DMA descriptor which manages the transfer details.
 147 */
 148struct tegra_dma_sg_req {
 149	struct tegra_dma_channel_regs	ch_regs;
 150	unsigned int			req_len;
 151	bool				configured;
 152	bool				last_sg;
 153	struct list_head		node;
 154	struct tegra_dma_desc		*dma_desc;
 155	unsigned int			words_xferred;
 156};
 157
 158/*
 159 * tegra_dma_desc: Tegra DMA descriptors which manages the client requests.
 160 * This descriptor keep track of transfer status, callbacks and request
 161 * counts etc.
 162 */
 163struct tegra_dma_desc {
 164	struct dma_async_tx_descriptor	txd;
 165	unsigned int			bytes_requested;
 166	unsigned int			bytes_transferred;
 167	enum dma_status			dma_status;
 168	struct list_head		node;
 169	struct list_head		tx_list;
 170	struct list_head		cb_node;
 171	int				cb_count;
 172};
 173
 174struct tegra_dma_channel;
 175
 176typedef void (*dma_isr_handler)(struct tegra_dma_channel *tdc,
 177				bool to_terminate);
 178
 179/* tegra_dma_channel: Channel specific information */
 180struct tegra_dma_channel {
 181	struct dma_chan		dma_chan;
 182	char			name[12];
 183	bool			config_init;
 184	int			id;
 185	int			irq;
 186	void __iomem		*chan_addr;
 187	spinlock_t		lock;
 188	bool			busy;
 189	struct tegra_dma	*tdma;
 190	bool			cyclic;
 191
 192	/* Different lists for managing the requests */
 193	struct list_head	free_sg_req;
 194	struct list_head	pending_sg_req;
 195	struct list_head	free_dma_desc;
 196	struct list_head	cb_desc;
 197
 198	/* ISR handler and tasklet for bottom half of isr handling */
 199	dma_isr_handler		isr_handler;
 200	struct tasklet_struct	tasklet;
 201
 202	/* Channel-slave specific configuration */
 203	unsigned int slave_id;
 204	struct dma_slave_config dma_sconfig;
 205	struct tegra_dma_channel_regs	channel_reg;
 206};
 207
 208/* tegra_dma: Tegra DMA specific information */
 209struct tegra_dma {
 210	struct dma_device		dma_dev;
 211	struct device			*dev;
 212	struct clk			*dma_clk;
 213	struct reset_control		*rst;
 214	spinlock_t			global_lock;
 215	void __iomem			*base_addr;
 216	const struct tegra_dma_chip_data *chip_data;
 217
 218	/*
 219	 * Counter for managing global pausing of the DMA controller.
 220	 * Only applicable for devices that don't support individual
 221	 * channel pausing.
 222	 */
 223	u32				global_pause_count;
 224
 225	/* Some register need to be cache before suspend */
 226	u32				reg_gen;
 227
 228	/* Last member of the structure */
 229	struct tegra_dma_channel channels[0];
 230};
 231
 232static inline void tdma_write(struct tegra_dma *tdma, u32 reg, u32 val)
 233{
 234	writel(val, tdma->base_addr + reg);
 235}
 236
 237static inline u32 tdma_read(struct tegra_dma *tdma, u32 reg)
 238{
 239	return readl(tdma->base_addr + reg);
 240}
 241
 242static inline void tdc_write(struct tegra_dma_channel *tdc,
 243		u32 reg, u32 val)
 244{
 245	writel(val, tdc->chan_addr + reg);
 246}
 247
 248static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
 249{
 250	return readl(tdc->chan_addr + reg);
 251}
 252
 253static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
 254{
 255	return container_of(dc, struct tegra_dma_channel, dma_chan);
 256}
 257
 258static inline struct tegra_dma_desc *txd_to_tegra_dma_desc(
 259		struct dma_async_tx_descriptor *td)
 260{
 261	return container_of(td, struct tegra_dma_desc, txd);
 262}
 263
 264static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
 265{
 266	return &tdc->dma_chan.dev->device;
 267}
 268
 269static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *tx);
 270static int tegra_dma_runtime_suspend(struct device *dev);
 271static int tegra_dma_runtime_resume(struct device *dev);
 272
 273/* Get DMA desc from free list, if not there then allocate it.  */
 274static struct tegra_dma_desc *tegra_dma_desc_get(
 275		struct tegra_dma_channel *tdc)
 276{
 277	struct tegra_dma_desc *dma_desc;
 278	unsigned long flags;
 279
 280	spin_lock_irqsave(&tdc->lock, flags);
 281
 282	/* Do not allocate if desc are waiting for ack */
 283	list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
 284		if (async_tx_test_ack(&dma_desc->txd)) {
 285			list_del(&dma_desc->node);
 286			spin_unlock_irqrestore(&tdc->lock, flags);
 287			dma_desc->txd.flags = 0;
 288			return dma_desc;
 289		}
 290	}
 291
 292	spin_unlock_irqrestore(&tdc->lock, flags);
 293
 294	/* Allocate DMA desc */
 295	dma_desc = kzalloc(sizeof(*dma_desc), GFP_NOWAIT);
 296	if (!dma_desc)
 297		return NULL;
 298
 299	dma_async_tx_descriptor_init(&dma_desc->txd, &tdc->dma_chan);
 300	dma_desc->txd.tx_submit = tegra_dma_tx_submit;
 301	dma_desc->txd.flags = 0;
 302	return dma_desc;
 303}
 304
 305static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
 306		struct tegra_dma_desc *dma_desc)
 307{
 308	unsigned long flags;
 309
 310	spin_lock_irqsave(&tdc->lock, flags);
 311	if (!list_empty(&dma_desc->tx_list))
 312		list_splice_init(&dma_desc->tx_list, &tdc->free_sg_req);
 313	list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 314	spin_unlock_irqrestore(&tdc->lock, flags);
 315}
 316
 317static struct tegra_dma_sg_req *tegra_dma_sg_req_get(
 318		struct tegra_dma_channel *tdc)
 319{
 320	struct tegra_dma_sg_req *sg_req = NULL;
 321	unsigned long flags;
 322
 323	spin_lock_irqsave(&tdc->lock, flags);
 324	if (!list_empty(&tdc->free_sg_req)) {
 325		sg_req = list_first_entry(&tdc->free_sg_req,
 326					typeof(*sg_req), node);
 327		list_del(&sg_req->node);
 328		spin_unlock_irqrestore(&tdc->lock, flags);
 329		return sg_req;
 330	}
 331	spin_unlock_irqrestore(&tdc->lock, flags);
 332
 333	sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_NOWAIT);
 334
 335	return sg_req;
 336}
 337
 338static int tegra_dma_slave_config(struct dma_chan *dc,
 339		struct dma_slave_config *sconfig)
 340{
 341	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 342
 343	if (!list_empty(&tdc->pending_sg_req)) {
 344		dev_err(tdc2dev(tdc), "Configuration not allowed\n");
 345		return -EBUSY;
 346	}
 347
 348	memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
 349	if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID &&
 350	    sconfig->device_fc) {
 351		if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK)
 352			return -EINVAL;
 353		tdc->slave_id = sconfig->slave_id;
 354	}
 355	tdc->config_init = true;
 356	return 0;
 357}
 358
 359static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
 360	bool wait_for_burst_complete)
 361{
 362	struct tegra_dma *tdma = tdc->tdma;
 363
 364	spin_lock(&tdma->global_lock);
 365
 366	if (tdc->tdma->global_pause_count == 0) {
 367		tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
 368		if (wait_for_burst_complete)
 369			udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 370	}
 371
 372	tdc->tdma->global_pause_count++;
 373
 374	spin_unlock(&tdma->global_lock);
 375}
 376
 377static void tegra_dma_global_resume(struct tegra_dma_channel *tdc)
 378{
 379	struct tegra_dma *tdma = tdc->tdma;
 380
 381	spin_lock(&tdma->global_lock);
 382
 383	if (WARN_ON(tdc->tdma->global_pause_count == 0))
 384		goto out;
 385
 386	if (--tdc->tdma->global_pause_count == 0)
 387		tdma_write(tdma, TEGRA_APBDMA_GENERAL,
 388			   TEGRA_APBDMA_GENERAL_ENABLE);
 389
 390out:
 391	spin_unlock(&tdma->global_lock);
 392}
 393
 394static void tegra_dma_pause(struct tegra_dma_channel *tdc,
 395	bool wait_for_burst_complete)
 396{
 397	struct tegra_dma *tdma = tdc->tdma;
 398
 399	if (tdma->chip_data->support_channel_pause) {
 400		tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE,
 401				TEGRA_APBDMA_CHAN_CSRE_PAUSE);
 402		if (wait_for_burst_complete)
 403			udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 404	} else {
 405		tegra_dma_global_pause(tdc, wait_for_burst_complete);
 406	}
 407}
 408
 409static void tegra_dma_resume(struct tegra_dma_channel *tdc)
 410{
 411	struct tegra_dma *tdma = tdc->tdma;
 412
 413	if (tdma->chip_data->support_channel_pause) {
 414		tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE, 0);
 415	} else {
 416		tegra_dma_global_resume(tdc);
 417	}
 418}
 419
 420static void tegra_dma_stop(struct tegra_dma_channel *tdc)
 421{
 422	u32 csr;
 423	u32 status;
 424
 425	/* Disable interrupts */
 426	csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
 427	csr &= ~TEGRA_APBDMA_CSR_IE_EOC;
 428	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
 429
 430	/* Disable DMA */
 431	csr &= ~TEGRA_APBDMA_CSR_ENB;
 432	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
 433
 434	/* Clear interrupt status if it is there */
 435	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 436	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 437		dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
 438		tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
 439	}
 440	tdc->busy = false;
 441}
 442
 443static void tegra_dma_start(struct tegra_dma_channel *tdc,
 444		struct tegra_dma_sg_req *sg_req)
 445{
 446	struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
 447
 448	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, ch_regs->csr);
 449	tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_regs->apb_seq);
 450	tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_regs->apb_ptr);
 451	tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_regs->ahb_seq);
 452	tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_regs->ahb_ptr);
 453	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 454		tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT, ch_regs->wcount);
 455
 456	/* Start DMA */
 457	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
 458				ch_regs->csr | TEGRA_APBDMA_CSR_ENB);
 459}
 460
 461static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
 462		struct tegra_dma_sg_req *nsg_req)
 463{
 464	unsigned long status;
 465
 466	/*
 467	 * The DMA controller reloads the new configuration for next transfer
 468	 * after last burst of current transfer completes.
 469	 * If there is no IEC status then this makes sure that last burst
 470	 * has not be completed. There may be case that last burst is on
 471	 * flight and so it can complete but because DMA is paused, it
 472	 * will not generates interrupt as well as not reload the new
 473	 * configuration.
 474	 * If there is already IEC status then interrupt handler need to
 475	 * load new configuration.
 476	 */
 477	tegra_dma_pause(tdc, false);
 478	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 479
 480	/*
 481	 * If interrupt is pending then do nothing as the ISR will handle
 482	 * the programing for new request.
 483	 */
 484	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 485		dev_err(tdc2dev(tdc),
 486			"Skipping new configuration as interrupt is pending\n");
 487		tegra_dma_resume(tdc);
 488		return;
 489	}
 490
 491	/* Safe to program new configuration */
 492	tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, nsg_req->ch_regs.apb_ptr);
 493	tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
 494	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 495		tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
 496						nsg_req->ch_regs.wcount);
 497	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
 498				nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
 499	nsg_req->configured = true;
 500	nsg_req->words_xferred = 0;
 501
 502	tegra_dma_resume(tdc);
 503}
 504
 505static void tdc_start_head_req(struct tegra_dma_channel *tdc)
 506{
 507	struct tegra_dma_sg_req *sg_req;
 508
 509	if (list_empty(&tdc->pending_sg_req))
 510		return;
 511
 512	sg_req = list_first_entry(&tdc->pending_sg_req,
 513					typeof(*sg_req), node);
 514	tegra_dma_start(tdc, sg_req);
 515	sg_req->configured = true;
 516	sg_req->words_xferred = 0;
 517	tdc->busy = true;
 518}
 519
 520static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
 521{
 522	struct tegra_dma_sg_req *hsgreq;
 523	struct tegra_dma_sg_req *hnsgreq;
 524
 525	if (list_empty(&tdc->pending_sg_req))
 526		return;
 527
 528	hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
 529	if (!list_is_last(&hsgreq->node, &tdc->pending_sg_req)) {
 530		hnsgreq = list_first_entry(&hsgreq->node,
 531					typeof(*hnsgreq), node);
 532		tegra_dma_configure_for_next(tdc, hnsgreq);
 533	}
 534}
 535
 536static inline int get_current_xferred_count(struct tegra_dma_channel *tdc,
 537	struct tegra_dma_sg_req *sg_req, unsigned long status)
 538{
 539	return sg_req->req_len - (status & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
 540}
 541
 542static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
 543{
 544	struct tegra_dma_sg_req *sgreq;
 545	struct tegra_dma_desc *dma_desc;
 546
 547	while (!list_empty(&tdc->pending_sg_req)) {
 548		sgreq = list_first_entry(&tdc->pending_sg_req,
 549						typeof(*sgreq), node);
 550		list_move_tail(&sgreq->node, &tdc->free_sg_req);
 551		if (sgreq->last_sg) {
 552			dma_desc = sgreq->dma_desc;
 553			dma_desc->dma_status = DMA_ERROR;
 554			list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 555
 556			/* Add in cb list if it is not there. */
 557			if (!dma_desc->cb_count)
 558				list_add_tail(&dma_desc->cb_node,
 559							&tdc->cb_desc);
 560			dma_desc->cb_count++;
 561		}
 562	}
 563	tdc->isr_handler = NULL;
 564}
 565
 566static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
 567		struct tegra_dma_sg_req *last_sg_req, bool to_terminate)
 568{
 569	struct tegra_dma_sg_req *hsgreq = NULL;
 570
 571	if (list_empty(&tdc->pending_sg_req)) {
 572		dev_err(tdc2dev(tdc), "DMA is running without req\n");
 573		tegra_dma_stop(tdc);
 574		return false;
 575	}
 576
 577	/*
 578	 * Check that head req on list should be in flight.
 579	 * If it is not in flight then abort transfer as
 580	 * looping of transfer can not continue.
 581	 */
 582	hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
 583	if (!hsgreq->configured) {
 584		tegra_dma_stop(tdc);
 585		dev_err(tdc2dev(tdc), "Error in DMA transfer, aborting DMA\n");
 586		tegra_dma_abort_all(tdc);
 587		return false;
 588	}
 589
 590	/* Configure next request */
 591	if (!to_terminate)
 592		tdc_configure_next_head_desc(tdc);
 593	return true;
 594}
 595
 596static void handle_once_dma_done(struct tegra_dma_channel *tdc,
 597	bool to_terminate)
 598{
 599	struct tegra_dma_sg_req *sgreq;
 600	struct tegra_dma_desc *dma_desc;
 601
 602	tdc->busy = false;
 603	sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
 604	dma_desc = sgreq->dma_desc;
 605	dma_desc->bytes_transferred += sgreq->req_len;
 606
 607	list_del(&sgreq->node);
 608	if (sgreq->last_sg) {
 609		dma_desc->dma_status = DMA_COMPLETE;
 610		dma_cookie_complete(&dma_desc->txd);
 611		if (!dma_desc->cb_count)
 612			list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
 613		dma_desc->cb_count++;
 614		list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 615	}
 616	list_add_tail(&sgreq->node, &tdc->free_sg_req);
 617
 618	/* Do not start DMA if it is going to be terminate */
 619	if (to_terminate || list_empty(&tdc->pending_sg_req))
 620		return;
 621
 622	tdc_start_head_req(tdc);
 623}
 624
 625static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
 626		bool to_terminate)
 627{
 628	struct tegra_dma_sg_req *sgreq;
 629	struct tegra_dma_desc *dma_desc;
 630	bool st;
 631
 632	sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
 633	dma_desc = sgreq->dma_desc;
 634	/* if we dma for long enough the transfer count will wrap */
 635	dma_desc->bytes_transferred =
 636		(dma_desc->bytes_transferred + sgreq->req_len) %
 637		dma_desc->bytes_requested;
 638
 639	/* Callback need to be call */
 640	if (!dma_desc->cb_count)
 641		list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
 642	dma_desc->cb_count++;
 643
 644	sgreq->words_xferred = 0;
 645
 646	/* If not last req then put at end of pending list */
 647	if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
 648		list_move_tail(&sgreq->node, &tdc->pending_sg_req);
 649		sgreq->configured = false;
 650		st = handle_continuous_head_request(tdc, sgreq, to_terminate);
 651		if (!st)
 652			dma_desc->dma_status = DMA_ERROR;
 653	}
 654}
 655
 656static void tegra_dma_tasklet(unsigned long data)
 657{
 658	struct tegra_dma_channel *tdc = (struct tegra_dma_channel *)data;
 659	struct dmaengine_desc_callback cb;
 660	struct tegra_dma_desc *dma_desc;
 661	unsigned long flags;
 662	int cb_count;
 663
 664	spin_lock_irqsave(&tdc->lock, flags);
 665	while (!list_empty(&tdc->cb_desc)) {
 666		dma_desc  = list_first_entry(&tdc->cb_desc,
 667					typeof(*dma_desc), cb_node);
 668		list_del(&dma_desc->cb_node);
 669		dmaengine_desc_get_callback(&dma_desc->txd, &cb);
 670		cb_count = dma_desc->cb_count;
 671		dma_desc->cb_count = 0;
 672		trace_tegra_dma_complete_cb(&tdc->dma_chan, cb_count,
 673					    cb.callback);
 674		spin_unlock_irqrestore(&tdc->lock, flags);
 675		while (cb_count--)
 676			dmaengine_desc_callback_invoke(&cb, NULL);
 677		spin_lock_irqsave(&tdc->lock, flags);
 678	}
 679	spin_unlock_irqrestore(&tdc->lock, flags);
 680}
 681
 682static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
 683{
 684	struct tegra_dma_channel *tdc = dev_id;
 685	unsigned long status;
 686	unsigned long flags;
 687
 688	spin_lock_irqsave(&tdc->lock, flags);
 689
 690	trace_tegra_dma_isr(&tdc->dma_chan, irq);
 691	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 692	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 693		tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
 694		tdc->isr_handler(tdc, false);
 695		tasklet_schedule(&tdc->tasklet);
 696		spin_unlock_irqrestore(&tdc->lock, flags);
 697		return IRQ_HANDLED;
 698	}
 699
 700	spin_unlock_irqrestore(&tdc->lock, flags);
 701	dev_info(tdc2dev(tdc),
 702		"Interrupt already served status 0x%08lx\n", status);
 703	return IRQ_NONE;
 704}
 705
 706static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *txd)
 707{
 708	struct tegra_dma_desc *dma_desc = txd_to_tegra_dma_desc(txd);
 709	struct tegra_dma_channel *tdc = to_tegra_dma_chan(txd->chan);
 710	unsigned long flags;
 711	dma_cookie_t cookie;
 712
 713	spin_lock_irqsave(&tdc->lock, flags);
 714	dma_desc->dma_status = DMA_IN_PROGRESS;
 715	cookie = dma_cookie_assign(&dma_desc->txd);
 716	list_splice_tail_init(&dma_desc->tx_list, &tdc->pending_sg_req);
 717	spin_unlock_irqrestore(&tdc->lock, flags);
 718	return cookie;
 719}
 720
 721static void tegra_dma_issue_pending(struct dma_chan *dc)
 722{
 723	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 724	unsigned long flags;
 725
 726	spin_lock_irqsave(&tdc->lock, flags);
 727	if (list_empty(&tdc->pending_sg_req)) {
 728		dev_err(tdc2dev(tdc), "No DMA request\n");
 729		goto end;
 730	}
 731	if (!tdc->busy) {
 732		tdc_start_head_req(tdc);
 733
 734		/* Continuous single mode: Configure next req */
 735		if (tdc->cyclic) {
 736			/*
 737			 * Wait for 1 burst time for configure DMA for
 738			 * next transfer.
 739			 */
 740			udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 741			tdc_configure_next_head_desc(tdc);
 742		}
 743	}
 744end:
 745	spin_unlock_irqrestore(&tdc->lock, flags);
 746}
 747
 748static int tegra_dma_terminate_all(struct dma_chan *dc)
 749{
 750	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 751	struct tegra_dma_sg_req *sgreq;
 752	struct tegra_dma_desc *dma_desc;
 753	unsigned long flags;
 754	unsigned long status;
 755	unsigned long wcount;
 756	bool was_busy;
 757
 758	spin_lock_irqsave(&tdc->lock, flags);
 759	if (list_empty(&tdc->pending_sg_req)) {
 760		spin_unlock_irqrestore(&tdc->lock, flags);
 761		return 0;
 762	}
 763
 764	if (!tdc->busy)
 765		goto skip_dma_stop;
 766
 767	/* Pause DMA before checking the queue status */
 768	tegra_dma_pause(tdc, true);
 769
 770	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 771	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 772		dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
 773		tdc->isr_handler(tdc, true);
 774		status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 775	}
 776	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 777		wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
 778	else
 779		wcount = status;
 780
 781	was_busy = tdc->busy;
 782	tegra_dma_stop(tdc);
 783
 784	if (!list_empty(&tdc->pending_sg_req) && was_busy) {
 785		sgreq = list_first_entry(&tdc->pending_sg_req,
 786					typeof(*sgreq), node);
 787		sgreq->dma_desc->bytes_transferred +=
 788				get_current_xferred_count(tdc, sgreq, wcount);
 789	}
 790	tegra_dma_resume(tdc);
 791
 792skip_dma_stop:
 793	tegra_dma_abort_all(tdc);
 794
 795	while (!list_empty(&tdc->cb_desc)) {
 796		dma_desc  = list_first_entry(&tdc->cb_desc,
 797					typeof(*dma_desc), cb_node);
 798		list_del(&dma_desc->cb_node);
 799		dma_desc->cb_count = 0;
 800	}
 801	spin_unlock_irqrestore(&tdc->lock, flags);
 802	return 0;
 803}
 804
 805static unsigned int tegra_dma_sg_bytes_xferred(struct tegra_dma_channel *tdc,
 806					       struct tegra_dma_sg_req *sg_req)
 807{
 808	unsigned long status, wcount = 0;
 809
 810	if (!list_is_first(&sg_req->node, &tdc->pending_sg_req))
 811		return 0;
 812
 813	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 814		wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
 815
 816	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 817
 818	if (!tdc->tdma->chip_data->support_separate_wcount_reg)
 819		wcount = status;
 820
 821	if (status & TEGRA_APBDMA_STATUS_ISE_EOC)
 822		return sg_req->req_len;
 823
 824	wcount = get_current_xferred_count(tdc, sg_req, wcount);
 825
 826	if (!wcount) {
 827		/*
 828		 * If wcount wasn't ever polled for this SG before, then
 829		 * simply assume that transfer hasn't started yet.
 830		 *
 831		 * Otherwise it's the end of the transfer.
 832		 *
 833		 * The alternative would be to poll the status register
 834		 * until EOC bit is set or wcount goes UP. That's so
 835		 * because EOC bit is getting set only after the last
 836		 * burst's completion and counter is less than the actual
 837		 * transfer size by 4 bytes. The counter value wraps around
 838		 * in a cyclic mode before EOC is set(!), so we can't easily
 839		 * distinguish start of transfer from its end.
 840		 */
 841		if (sg_req->words_xferred)
 842			wcount = sg_req->req_len - 4;
 843
 844	} else if (wcount < sg_req->words_xferred) {
 845		/*
 846		 * This case will never happen for a non-cyclic transfer.
 847		 *
 848		 * For a cyclic transfer, although it is possible for the
 849		 * next transfer to have already started (resetting the word
 850		 * count), this case should still not happen because we should
 851		 * have detected that the EOC bit is set and hence the transfer
 852		 * was completed.
 853		 */
 854		WARN_ON_ONCE(1);
 855
 856		wcount = sg_req->req_len - 4;
 857	} else {
 858		sg_req->words_xferred = wcount;
 859	}
 860
 861	return wcount;
 862}
 863
 864static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
 865	dma_cookie_t cookie, struct dma_tx_state *txstate)
 866{
 867	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 868	struct tegra_dma_desc *dma_desc;
 869	struct tegra_dma_sg_req *sg_req;
 870	enum dma_status ret;
 871	unsigned long flags;
 872	unsigned int residual;
 873	unsigned int bytes = 0;
 874
 875	ret = dma_cookie_status(dc, cookie, txstate);
 876	if (ret == DMA_COMPLETE)
 877		return ret;
 878
 879	spin_lock_irqsave(&tdc->lock, flags);
 880
 881	/* Check on wait_ack desc status */
 882	list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
 883		if (dma_desc->txd.cookie == cookie) {
 884			ret = dma_desc->dma_status;
 885			goto found;
 886		}
 887	}
 888
 889	/* Check in pending list */
 890	list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
 891		dma_desc = sg_req->dma_desc;
 892		if (dma_desc->txd.cookie == cookie) {
 893			bytes = tegra_dma_sg_bytes_xferred(tdc, sg_req);
 894			ret = dma_desc->dma_status;
 895			goto found;
 896		}
 897	}
 898
 899	dev_dbg(tdc2dev(tdc), "cookie %d not found\n", cookie);
 900	dma_desc = NULL;
 901
 902found:
 903	if (dma_desc && txstate) {
 904		residual = dma_desc->bytes_requested -
 905			   ((dma_desc->bytes_transferred + bytes) %
 906			    dma_desc->bytes_requested);
 907		dma_set_residue(txstate, residual);
 908	}
 909
 910	trace_tegra_dma_tx_status(&tdc->dma_chan, cookie, txstate);
 911	spin_unlock_irqrestore(&tdc->lock, flags);
 912	return ret;
 913}
 914
 915static inline int get_bus_width(struct tegra_dma_channel *tdc,
 916		enum dma_slave_buswidth slave_bw)
 917{
 918	switch (slave_bw) {
 919	case DMA_SLAVE_BUSWIDTH_1_BYTE:
 920		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8;
 921	case DMA_SLAVE_BUSWIDTH_2_BYTES:
 922		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16;
 923	case DMA_SLAVE_BUSWIDTH_4_BYTES:
 924		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
 925	case DMA_SLAVE_BUSWIDTH_8_BYTES:
 926		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64;
 927	default:
 928		dev_warn(tdc2dev(tdc),
 929			"slave bw is not supported, using 32bits\n");
 930		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
 931	}
 932}
 933
 934static inline int get_burst_size(struct tegra_dma_channel *tdc,
 935	u32 burst_size, enum dma_slave_buswidth slave_bw, int len)
 936{
 937	int burst_byte;
 938	int burst_ahb_width;
 939
 940	/*
 941	 * burst_size from client is in terms of the bus_width.
 942	 * convert them into AHB memory width which is 4 byte.
 943	 */
 944	burst_byte = burst_size * slave_bw;
 945	burst_ahb_width = burst_byte / 4;
 946
 947	/* If burst size is 0 then calculate the burst size based on length */
 948	if (!burst_ahb_width) {
 949		if (len & 0xF)
 950			return TEGRA_APBDMA_AHBSEQ_BURST_1;
 951		else if ((len >> 4) & 0x1)
 952			return TEGRA_APBDMA_AHBSEQ_BURST_4;
 953		else
 954			return TEGRA_APBDMA_AHBSEQ_BURST_8;
 955	}
 956	if (burst_ahb_width < 4)
 957		return TEGRA_APBDMA_AHBSEQ_BURST_1;
 958	else if (burst_ahb_width < 8)
 959		return TEGRA_APBDMA_AHBSEQ_BURST_4;
 960	else
 961		return TEGRA_APBDMA_AHBSEQ_BURST_8;
 962}
 963
 964static int get_transfer_param(struct tegra_dma_channel *tdc,
 965	enum dma_transfer_direction direction, unsigned long *apb_addr,
 966	unsigned long *apb_seq,	unsigned long *csr, unsigned int *burst_size,
 967	enum dma_slave_buswidth *slave_bw)
 968{
 969	switch (direction) {
 970	case DMA_MEM_TO_DEV:
 971		*apb_addr = tdc->dma_sconfig.dst_addr;
 972		*apb_seq = get_bus_width(tdc, tdc->dma_sconfig.dst_addr_width);
 973		*burst_size = tdc->dma_sconfig.dst_maxburst;
 974		*slave_bw = tdc->dma_sconfig.dst_addr_width;
 975		*csr = TEGRA_APBDMA_CSR_DIR;
 976		return 0;
 977
 978	case DMA_DEV_TO_MEM:
 979		*apb_addr = tdc->dma_sconfig.src_addr;
 980		*apb_seq = get_bus_width(tdc, tdc->dma_sconfig.src_addr_width);
 981		*burst_size = tdc->dma_sconfig.src_maxburst;
 982		*slave_bw = tdc->dma_sconfig.src_addr_width;
 983		*csr = 0;
 984		return 0;
 985
 986	default:
 987		dev_err(tdc2dev(tdc), "DMA direction is not supported\n");
 988		return -EINVAL;
 989	}
 990	return -EINVAL;
 991}
 992
 993static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
 994	struct tegra_dma_channel_regs *ch_regs, u32 len)
 995{
 996	u32 len_field = (len - 4) & 0xFFFC;
 997
 998	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 999		ch_regs->wcount = len_field;
1000	else
1001		ch_regs->csr |= len_field;
1002}
1003
1004static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
1005	struct dma_chan *dc, struct scatterlist *sgl, unsigned int sg_len,
1006	enum dma_transfer_direction direction, unsigned long flags,
1007	void *context)
1008{
1009	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1010	struct tegra_dma_desc *dma_desc;
1011	unsigned int i;
1012	struct scatterlist *sg;
1013	unsigned long csr, ahb_seq, apb_ptr, apb_seq;
1014	struct list_head req_list;
1015	struct tegra_dma_sg_req  *sg_req = NULL;
1016	u32 burst_size;
1017	enum dma_slave_buswidth slave_bw;
1018
1019	if (!tdc->config_init) {
1020		dev_err(tdc2dev(tdc), "DMA channel is not configured\n");
1021		return NULL;
1022	}
1023	if (sg_len < 1) {
1024		dev_err(tdc2dev(tdc), "Invalid segment length %d\n", sg_len);
1025		return NULL;
1026	}
1027
1028	if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
1029				&burst_size, &slave_bw) < 0)
1030		return NULL;
1031
1032	INIT_LIST_HEAD(&req_list);
1033
1034	ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
1035	ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
1036					TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
1037	ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
1038
1039	csr |= TEGRA_APBDMA_CSR_ONCE;
1040
1041	if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) {
1042		csr |= TEGRA_APBDMA_CSR_FLOW;
1043		csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
1044	}
1045
1046	if (flags & DMA_PREP_INTERRUPT) {
1047		csr |= TEGRA_APBDMA_CSR_IE_EOC;
1048	} else {
1049		WARN_ON_ONCE(1);
1050		return NULL;
1051	}
1052
1053	apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
1054
1055	dma_desc = tegra_dma_desc_get(tdc);
1056	if (!dma_desc) {
1057		dev_err(tdc2dev(tdc), "DMA descriptors not available\n");
1058		return NULL;
1059	}
1060	INIT_LIST_HEAD(&dma_desc->tx_list);
1061	INIT_LIST_HEAD(&dma_desc->cb_node);
1062	dma_desc->cb_count = 0;
1063	dma_desc->bytes_requested = 0;
1064	dma_desc->bytes_transferred = 0;
1065	dma_desc->dma_status = DMA_IN_PROGRESS;
1066
1067	/* Make transfer requests */
1068	for_each_sg(sgl, sg, sg_len, i) {
1069		u32 len, mem;
1070
1071		mem = sg_dma_address(sg);
1072		len = sg_dma_len(sg);
1073
1074		if ((len & 3) || (mem & 3) ||
1075				(len > tdc->tdma->chip_data->max_dma_count)) {
1076			dev_err(tdc2dev(tdc),
1077				"DMA length/memory address is not supported\n");
1078			tegra_dma_desc_put(tdc, dma_desc);
1079			return NULL;
1080		}
1081
1082		sg_req = tegra_dma_sg_req_get(tdc);
1083		if (!sg_req) {
1084			dev_err(tdc2dev(tdc), "DMA sg-req not available\n");
1085			tegra_dma_desc_put(tdc, dma_desc);
1086			return NULL;
1087		}
1088
1089		ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1090		dma_desc->bytes_requested += len;
1091
1092		sg_req->ch_regs.apb_ptr = apb_ptr;
1093		sg_req->ch_regs.ahb_ptr = mem;
1094		sg_req->ch_regs.csr = csr;
1095		tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1096		sg_req->ch_regs.apb_seq = apb_seq;
1097		sg_req->ch_regs.ahb_seq = ahb_seq;
1098		sg_req->configured = false;
1099		sg_req->last_sg = false;
1100		sg_req->dma_desc = dma_desc;
1101		sg_req->req_len = len;
1102
1103		list_add_tail(&sg_req->node, &dma_desc->tx_list);
1104	}
1105	sg_req->last_sg = true;
1106	if (flags & DMA_CTRL_ACK)
1107		dma_desc->txd.flags = DMA_CTRL_ACK;
1108
1109	/*
1110	 * Make sure that mode should not be conflicting with currently
1111	 * configured mode.
1112	 */
1113	if (!tdc->isr_handler) {
1114		tdc->isr_handler = handle_once_dma_done;
1115		tdc->cyclic = false;
1116	} else {
1117		if (tdc->cyclic) {
1118			dev_err(tdc2dev(tdc), "DMA configured in cyclic mode\n");
1119			tegra_dma_desc_put(tdc, dma_desc);
1120			return NULL;
1121		}
1122	}
1123
1124	return &dma_desc->txd;
1125}
1126
1127static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
1128	struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
1129	size_t period_len, enum dma_transfer_direction direction,
1130	unsigned long flags)
1131{
1132	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1133	struct tegra_dma_desc *dma_desc = NULL;
1134	struct tegra_dma_sg_req *sg_req = NULL;
1135	unsigned long csr, ahb_seq, apb_ptr, apb_seq;
1136	int len;
1137	size_t remain_len;
1138	dma_addr_t mem = buf_addr;
1139	u32 burst_size;
1140	enum dma_slave_buswidth slave_bw;
1141
1142	if (!buf_len || !period_len) {
1143		dev_err(tdc2dev(tdc), "Invalid buffer/period len\n");
1144		return NULL;
1145	}
1146
1147	if (!tdc->config_init) {
1148		dev_err(tdc2dev(tdc), "DMA slave is not configured\n");
1149		return NULL;
1150	}
1151
1152	/*
1153	 * We allow to take more number of requests till DMA is
1154	 * not started. The driver will loop over all requests.
1155	 * Once DMA is started then new requests can be queued only after
1156	 * terminating the DMA.
1157	 */
1158	if (tdc->busy) {
1159		dev_err(tdc2dev(tdc), "Request not allowed when DMA running\n");
1160		return NULL;
1161	}
1162
1163	/*
1164	 * We only support cycle transfer when buf_len is multiple of
1165	 * period_len.
1166	 */
1167	if (buf_len % period_len) {
1168		dev_err(tdc2dev(tdc), "buf_len is not multiple of period_len\n");
1169		return NULL;
1170	}
1171
1172	len = period_len;
1173	if ((len & 3) || (buf_addr & 3) ||
1174			(len > tdc->tdma->chip_data->max_dma_count)) {
1175		dev_err(tdc2dev(tdc), "Req len/mem address is not correct\n");
1176		return NULL;
1177	}
1178
1179	if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
1180				&burst_size, &slave_bw) < 0)
1181		return NULL;
1182
1183	ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
1184	ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
1185					TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
1186	ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
1187
1188	if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) {
1189		csr |= TEGRA_APBDMA_CSR_FLOW;
1190		csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
1191	}
1192
1193	if (flags & DMA_PREP_INTERRUPT) {
1194		csr |= TEGRA_APBDMA_CSR_IE_EOC;
1195	} else {
1196		WARN_ON_ONCE(1);
1197		return NULL;
1198	}
1199
1200	apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
1201
1202	dma_desc = tegra_dma_desc_get(tdc);
1203	if (!dma_desc) {
1204		dev_err(tdc2dev(tdc), "not enough descriptors available\n");
1205		return NULL;
1206	}
1207
1208	INIT_LIST_HEAD(&dma_desc->tx_list);
1209	INIT_LIST_HEAD(&dma_desc->cb_node);
1210	dma_desc->cb_count = 0;
1211
1212	dma_desc->bytes_transferred = 0;
1213	dma_desc->bytes_requested = buf_len;
1214	remain_len = buf_len;
1215
1216	/* Split transfer equal to period size */
1217	while (remain_len) {
1218		sg_req = tegra_dma_sg_req_get(tdc);
1219		if (!sg_req) {
1220			dev_err(tdc2dev(tdc), "DMA sg-req not available\n");
1221			tegra_dma_desc_put(tdc, dma_desc);
1222			return NULL;
1223		}
1224
1225		ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1226		sg_req->ch_regs.apb_ptr = apb_ptr;
1227		sg_req->ch_regs.ahb_ptr = mem;
1228		sg_req->ch_regs.csr = csr;
1229		tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1230		sg_req->ch_regs.apb_seq = apb_seq;
1231		sg_req->ch_regs.ahb_seq = ahb_seq;
1232		sg_req->configured = false;
1233		sg_req->last_sg = false;
1234		sg_req->dma_desc = dma_desc;
1235		sg_req->req_len = len;
1236
1237		list_add_tail(&sg_req->node, &dma_desc->tx_list);
1238		remain_len -= len;
1239		mem += len;
1240	}
1241	sg_req->last_sg = true;
1242	if (flags & DMA_CTRL_ACK)
1243		dma_desc->txd.flags = DMA_CTRL_ACK;
1244
1245	/*
1246	 * Make sure that mode should not be conflicting with currently
1247	 * configured mode.
1248	 */
1249	if (!tdc->isr_handler) {
1250		tdc->isr_handler = handle_cont_sngl_cycle_dma_done;
1251		tdc->cyclic = true;
1252	} else {
1253		if (!tdc->cyclic) {
1254			dev_err(tdc2dev(tdc), "DMA configuration conflict\n");
1255			tegra_dma_desc_put(tdc, dma_desc);
1256			return NULL;
1257		}
1258	}
1259
1260	return &dma_desc->txd;
1261}
1262
1263static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
1264{
1265	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1266	struct tegra_dma *tdma = tdc->tdma;
1267	int ret;
1268
1269	dma_cookie_init(&tdc->dma_chan);
1270	tdc->config_init = false;
1271
1272	ret = pm_runtime_get_sync(tdma->dev);
1273	if (ret < 0)
1274		return ret;
1275
1276	return 0;
1277}
1278
1279static void tegra_dma_free_chan_resources(struct dma_chan *dc)
1280{
1281	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1282	struct tegra_dma *tdma = tdc->tdma;
1283	struct tegra_dma_desc *dma_desc;
1284	struct tegra_dma_sg_req *sg_req;
1285	struct list_head dma_desc_list;
1286	struct list_head sg_req_list;
1287	unsigned long flags;
1288
1289	INIT_LIST_HEAD(&dma_desc_list);
1290	INIT_LIST_HEAD(&sg_req_list);
1291
1292	dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
1293
1294	if (tdc->busy)
1295		tegra_dma_terminate_all(dc);
1296
1297	spin_lock_irqsave(&tdc->lock, flags);
1298	list_splice_init(&tdc->pending_sg_req, &sg_req_list);
1299	list_splice_init(&tdc->free_sg_req, &sg_req_list);
1300	list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
1301	INIT_LIST_HEAD(&tdc->cb_desc);
1302	tdc->config_init = false;
1303	tdc->isr_handler = NULL;
1304	spin_unlock_irqrestore(&tdc->lock, flags);
1305
1306	while (!list_empty(&dma_desc_list)) {
1307		dma_desc = list_first_entry(&dma_desc_list,
1308					typeof(*dma_desc), node);
1309		list_del(&dma_desc->node);
1310		kfree(dma_desc);
1311	}
1312
1313	while (!list_empty(&sg_req_list)) {
1314		sg_req = list_first_entry(&sg_req_list, typeof(*sg_req), node);
1315		list_del(&sg_req->node);
1316		kfree(sg_req);
1317	}
1318	pm_runtime_put(tdma->dev);
1319
1320	tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1321}
1322
1323static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
1324					   struct of_dma *ofdma)
1325{
1326	struct tegra_dma *tdma = ofdma->of_dma_data;
1327	struct dma_chan *chan;
1328	struct tegra_dma_channel *tdc;
1329
1330	if (dma_spec->args[0] > TEGRA_APBDMA_CSR_REQ_SEL_MASK) {
1331		dev_err(tdma->dev, "Invalid slave id: %d\n", dma_spec->args[0]);
1332		return NULL;
1333	}
1334
1335	chan = dma_get_any_slave_channel(&tdma->dma_dev);
1336	if (!chan)
1337		return NULL;
1338
1339	tdc = to_tegra_dma_chan(chan);
1340	tdc->slave_id = dma_spec->args[0];
1341
1342	return chan;
1343}
1344
1345/* Tegra20 specific DMA controller information */
1346static const struct tegra_dma_chip_data tegra20_dma_chip_data = {
1347	.nr_channels		= 16,
1348	.channel_reg_size	= 0x20,
1349	.max_dma_count		= 1024UL * 64,
1350	.support_channel_pause	= false,
1351	.support_separate_wcount_reg = false,
1352};
1353
1354/* Tegra30 specific DMA controller information */
1355static const struct tegra_dma_chip_data tegra30_dma_chip_data = {
1356	.nr_channels		= 32,
1357	.channel_reg_size	= 0x20,
1358	.max_dma_count		= 1024UL * 64,
1359	.support_channel_pause	= false,
1360	.support_separate_wcount_reg = false,
1361};
1362
1363/* Tegra114 specific DMA controller information */
1364static const struct tegra_dma_chip_data tegra114_dma_chip_data = {
1365	.nr_channels		= 32,
1366	.channel_reg_size	= 0x20,
1367	.max_dma_count		= 1024UL * 64,
1368	.support_channel_pause	= true,
1369	.support_separate_wcount_reg = false,
1370};
1371
1372/* Tegra148 specific DMA controller information */
1373static const struct tegra_dma_chip_data tegra148_dma_chip_data = {
1374	.nr_channels		= 32,
1375	.channel_reg_size	= 0x40,
1376	.max_dma_count		= 1024UL * 64,
1377	.support_channel_pause	= true,
1378	.support_separate_wcount_reg = true,
1379};
1380
1381static int tegra_dma_probe(struct platform_device *pdev)
1382{
1383	struct resource *res;
1384	struct tegra_dma *tdma;
1385	int ret;
1386	int i;
1387	const struct tegra_dma_chip_data *cdata;
1388
1389	cdata = of_device_get_match_data(&pdev->dev);
1390	if (!cdata) {
1391		dev_err(&pdev->dev, "Error: No device match data found\n");
1392		return -ENODEV;
1393	}
1394
1395	tdma = devm_kzalloc(&pdev->dev,
1396			    struct_size(tdma, channels, cdata->nr_channels),
1397			    GFP_KERNEL);
1398	if (!tdma)
1399		return -ENOMEM;
1400
1401	tdma->dev = &pdev->dev;
1402	tdma->chip_data = cdata;
1403	platform_set_drvdata(pdev, tdma);
1404
1405	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1406	tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
1407	if (IS_ERR(tdma->base_addr))
1408		return PTR_ERR(tdma->base_addr);
1409
1410	tdma->dma_clk = devm_clk_get(&pdev->dev, NULL);
1411	if (IS_ERR(tdma->dma_clk)) {
1412		dev_err(&pdev->dev, "Error: Missing controller clock\n");
1413		return PTR_ERR(tdma->dma_clk);
1414	}
1415
1416	tdma->rst = devm_reset_control_get(&pdev->dev, "dma");
1417	if (IS_ERR(tdma->rst)) {
1418		dev_err(&pdev->dev, "Error: Missing reset\n");
1419		return PTR_ERR(tdma->rst);
1420	}
1421
1422	spin_lock_init(&tdma->global_lock);
1423
1424	pm_runtime_enable(&pdev->dev);
1425	if (!pm_runtime_enabled(&pdev->dev))
1426		ret = tegra_dma_runtime_resume(&pdev->dev);
1427	else
1428		ret = pm_runtime_get_sync(&pdev->dev);
1429
1430	if (ret < 0) {
1431		pm_runtime_disable(&pdev->dev);
1432		return ret;
1433	}
1434
1435	/* Reset DMA controller */
1436	reset_control_assert(tdma->rst);
1437	udelay(2);
1438	reset_control_deassert(tdma->rst);
1439
1440	/* Enable global DMA registers */
1441	tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
1442	tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1443	tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
1444
1445	pm_runtime_put(&pdev->dev);
1446
1447	INIT_LIST_HEAD(&tdma->dma_dev.channels);
1448	for (i = 0; i < cdata->nr_channels; i++) {
1449		struct tegra_dma_channel *tdc = &tdma->channels[i];
1450
1451		tdc->chan_addr = tdma->base_addr +
1452				 TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET +
1453				 (i * cdata->channel_reg_size);
1454
1455		res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1456		if (!res) {
1457			ret = -EINVAL;
1458			dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1459			goto err_irq;
1460		}
1461		tdc->irq = res->start;
1462		snprintf(tdc->name, sizeof(tdc->name), "apbdma.%d", i);
1463		ret = request_irq(tdc->irq, tegra_dma_isr, 0, tdc->name, tdc);
1464		if (ret) {
1465			dev_err(&pdev->dev,
1466				"request_irq failed with err %d channel %d\n",
1467				ret, i);
1468			goto err_irq;
1469		}
1470
1471		tdc->dma_chan.device = &tdma->dma_dev;
1472		dma_cookie_init(&tdc->dma_chan);
1473		list_add_tail(&tdc->dma_chan.device_node,
1474				&tdma->dma_dev.channels);
1475		tdc->tdma = tdma;
1476		tdc->id = i;
1477		tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1478
1479		tasklet_init(&tdc->tasklet, tegra_dma_tasklet,
1480				(unsigned long)tdc);
1481		spin_lock_init(&tdc->lock);
1482
1483		INIT_LIST_HEAD(&tdc->pending_sg_req);
1484		INIT_LIST_HEAD(&tdc->free_sg_req);
1485		INIT_LIST_HEAD(&tdc->free_dma_desc);
1486		INIT_LIST_HEAD(&tdc->cb_desc);
1487	}
1488
1489	dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
1490	dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
1491	dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
1492
1493	tdma->global_pause_count = 0;
1494	tdma->dma_dev.dev = &pdev->dev;
1495	tdma->dma_dev.device_alloc_chan_resources =
1496					tegra_dma_alloc_chan_resources;
1497	tdma->dma_dev.device_free_chan_resources =
1498					tegra_dma_free_chan_resources;
1499	tdma->dma_dev.device_prep_slave_sg = tegra_dma_prep_slave_sg;
1500	tdma->dma_dev.device_prep_dma_cyclic = tegra_dma_prep_dma_cyclic;
1501	tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1502		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1503		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1504		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1505	tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1506		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1507		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1508		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1509	tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1510	tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 
 
 
 
 
1511	tdma->dma_dev.device_config = tegra_dma_slave_config;
1512	tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
1513	tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
1514	tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
1515
1516	ret = dma_async_device_register(&tdma->dma_dev);
1517	if (ret < 0) {
1518		dev_err(&pdev->dev,
1519			"Tegra20 APB DMA driver registration failed %d\n", ret);
1520		goto err_irq;
1521	}
1522
1523	ret = of_dma_controller_register(pdev->dev.of_node,
1524					 tegra_dma_of_xlate, tdma);
1525	if (ret < 0) {
1526		dev_err(&pdev->dev,
1527			"Tegra20 APB DMA OF registration failed %d\n", ret);
1528		goto err_unregister_dma_dev;
1529	}
1530
1531	dev_info(&pdev->dev, "Tegra20 APB DMA driver register %d channels\n",
1532			cdata->nr_channels);
1533	return 0;
1534
1535err_unregister_dma_dev:
1536	dma_async_device_unregister(&tdma->dma_dev);
1537err_irq:
1538	while (--i >= 0) {
1539		struct tegra_dma_channel *tdc = &tdma->channels[i];
1540
1541		free_irq(tdc->irq, tdc);
1542		tasklet_kill(&tdc->tasklet);
1543	}
1544
1545	pm_runtime_disable(&pdev->dev);
1546	if (!pm_runtime_status_suspended(&pdev->dev))
1547		tegra_dma_runtime_suspend(&pdev->dev);
1548	return ret;
1549}
1550
1551static int tegra_dma_remove(struct platform_device *pdev)
1552{
1553	struct tegra_dma *tdma = platform_get_drvdata(pdev);
1554	int i;
1555	struct tegra_dma_channel *tdc;
1556
1557	dma_async_device_unregister(&tdma->dma_dev);
1558
1559	for (i = 0; i < tdma->chip_data->nr_channels; ++i) {
1560		tdc = &tdma->channels[i];
1561		free_irq(tdc->irq, tdc);
1562		tasklet_kill(&tdc->tasklet);
1563	}
1564
1565	pm_runtime_disable(&pdev->dev);
1566	if (!pm_runtime_status_suspended(&pdev->dev))
1567		tegra_dma_runtime_suspend(&pdev->dev);
1568
1569	return 0;
1570}
1571
1572static int tegra_dma_runtime_suspend(struct device *dev)
1573{
1574	struct tegra_dma *tdma = dev_get_drvdata(dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1575	int i;
 
 
 
 
 
 
1576
1577	tdma->reg_gen = tdma_read(tdma, TEGRA_APBDMA_GENERAL);
1578	for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1579		struct tegra_dma_channel *tdc = &tdma->channels[i];
1580		struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
1581
1582		/* Only save the state of DMA channels that are in use */
1583		if (!tdc->config_init)
1584			continue;
1585
1586		ch_reg->csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
1587		ch_reg->ahb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBPTR);
1588		ch_reg->apb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBPTR);
1589		ch_reg->ahb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBSEQ);
1590		ch_reg->apb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBSEQ);
1591		if (tdma->chip_data->support_separate_wcount_reg)
1592			ch_reg->wcount = tdc_read(tdc,
1593						  TEGRA_APBDMA_CHAN_WCOUNT);
1594	}
1595
1596	clk_disable_unprepare(tdma->dma_clk);
1597
1598	return 0;
1599}
1600
1601static int tegra_dma_runtime_resume(struct device *dev)
1602{
1603	struct tegra_dma *tdma = dev_get_drvdata(dev);
1604	int i, ret;
 
1605
1606	ret = clk_prepare_enable(tdma->dma_clk);
1607	if (ret < 0) {
1608		dev_err(dev, "clk_enable failed: %d\n", ret);
1609		return ret;
1610	}
1611
1612	tdma_write(tdma, TEGRA_APBDMA_GENERAL, tdma->reg_gen);
1613	tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1614	tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
1615
1616	for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1617		struct tegra_dma_channel *tdc = &tdma->channels[i];
1618		struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
1619
1620		/* Only restore the state of DMA channels that are in use */
1621		if (!tdc->config_init)
1622			continue;
1623
1624		if (tdma->chip_data->support_separate_wcount_reg)
1625			tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
1626				  ch_reg->wcount);
1627		tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_reg->apb_seq);
1628		tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_reg->apb_ptr);
1629		tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_reg->ahb_seq);
1630		tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_reg->ahb_ptr);
1631		tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
1632			(ch_reg->csr & ~TEGRA_APBDMA_CSR_ENB));
1633	}
1634
 
 
1635	return 0;
1636}
 
1637
1638static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
1639	SET_RUNTIME_PM_OPS(tegra_dma_runtime_suspend, tegra_dma_runtime_resume,
1640			   NULL)
1641	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1642				pm_runtime_force_resume)
1643};
1644
1645static const struct of_device_id tegra_dma_of_match[] = {
1646	{
1647		.compatible = "nvidia,tegra148-apbdma",
1648		.data = &tegra148_dma_chip_data,
1649	}, {
1650		.compatible = "nvidia,tegra114-apbdma",
1651		.data = &tegra114_dma_chip_data,
1652	}, {
1653		.compatible = "nvidia,tegra30-apbdma",
1654		.data = &tegra30_dma_chip_data,
1655	}, {
1656		.compatible = "nvidia,tegra20-apbdma",
1657		.data = &tegra20_dma_chip_data,
1658	}, {
1659	},
1660};
1661MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
1662
1663static struct platform_driver tegra_dmac_driver = {
1664	.driver = {
1665		.name	= "tegra-apbdma",
1666		.pm	= &tegra_dma_dev_pm_ops,
1667		.of_match_table = tegra_dma_of_match,
1668	},
1669	.probe		= tegra_dma_probe,
1670	.remove		= tegra_dma_remove,
1671};
1672
1673module_platform_driver(tegra_dmac_driver);
1674
1675MODULE_ALIAS("platform:tegra20-apbdma");
1676MODULE_DESCRIPTION("NVIDIA Tegra APB DMA Controller driver");
1677MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1678MODULE_LICENSE("GPL v2");
v4.10.11
 
   1/*
   2 * DMA driver for Nvidia's Tegra20 APB DMA controller.
   3 *
   4 * Copyright (c) 2012-2013, NVIDIA CORPORATION.  All rights reserved.
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms and conditions of the GNU General Public License,
   8 * version 2, as published by the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope it will be useful, but WITHOUT
  11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 * more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19#include <linux/bitops.h>
  20#include <linux/clk.h>
  21#include <linux/delay.h>
  22#include <linux/dmaengine.h>
  23#include <linux/dma-mapping.h>
  24#include <linux/err.h>
  25#include <linux/init.h>
  26#include <linux/interrupt.h>
  27#include <linux/io.h>
  28#include <linux/mm.h>
  29#include <linux/module.h>
  30#include <linux/of.h>
  31#include <linux/of_device.h>
  32#include <linux/of_dma.h>
  33#include <linux/platform_device.h>
  34#include <linux/pm.h>
  35#include <linux/pm_runtime.h>
  36#include <linux/reset.h>
  37#include <linux/slab.h>
  38
  39#include "dmaengine.h"
  40
 
 
 
  41#define TEGRA_APBDMA_GENERAL			0x0
  42#define TEGRA_APBDMA_GENERAL_ENABLE		BIT(31)
  43
  44#define TEGRA_APBDMA_CONTROL			0x010
  45#define TEGRA_APBDMA_IRQ_MASK			0x01c
  46#define TEGRA_APBDMA_IRQ_MASK_SET		0x020
  47
  48/* CSR register */
  49#define TEGRA_APBDMA_CHAN_CSR			0x00
  50#define TEGRA_APBDMA_CSR_ENB			BIT(31)
  51#define TEGRA_APBDMA_CSR_IE_EOC			BIT(30)
  52#define TEGRA_APBDMA_CSR_HOLD			BIT(29)
  53#define TEGRA_APBDMA_CSR_DIR			BIT(28)
  54#define TEGRA_APBDMA_CSR_ONCE			BIT(27)
  55#define TEGRA_APBDMA_CSR_FLOW			BIT(21)
  56#define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT		16
  57#define TEGRA_APBDMA_CSR_REQ_SEL_MASK		0x1F
  58#define TEGRA_APBDMA_CSR_WCOUNT_MASK		0xFFFC
  59
  60/* STATUS register */
  61#define TEGRA_APBDMA_CHAN_STATUS		0x004
  62#define TEGRA_APBDMA_STATUS_BUSY		BIT(31)
  63#define TEGRA_APBDMA_STATUS_ISE_EOC		BIT(30)
  64#define TEGRA_APBDMA_STATUS_HALT		BIT(29)
  65#define TEGRA_APBDMA_STATUS_PING_PONG		BIT(28)
  66#define TEGRA_APBDMA_STATUS_COUNT_SHIFT		2
  67#define TEGRA_APBDMA_STATUS_COUNT_MASK		0xFFFC
  68
  69#define TEGRA_APBDMA_CHAN_CSRE			0x00C
  70#define TEGRA_APBDMA_CHAN_CSRE_PAUSE		(1 << 31)
  71
  72/* AHB memory address */
  73#define TEGRA_APBDMA_CHAN_AHBPTR		0x010
  74
  75/* AHB sequence register */
  76#define TEGRA_APBDMA_CHAN_AHBSEQ		0x14
  77#define TEGRA_APBDMA_AHBSEQ_INTR_ENB		BIT(31)
  78#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_8		(0 << 28)
  79#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_16	(1 << 28)
  80#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32	(2 << 28)
  81#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_64	(3 << 28)
  82#define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_128	(4 << 28)
  83#define TEGRA_APBDMA_AHBSEQ_DATA_SWAP		BIT(27)
  84#define TEGRA_APBDMA_AHBSEQ_BURST_1		(4 << 24)
  85#define TEGRA_APBDMA_AHBSEQ_BURST_4		(5 << 24)
  86#define TEGRA_APBDMA_AHBSEQ_BURST_8		(6 << 24)
  87#define TEGRA_APBDMA_AHBSEQ_DBL_BUF		BIT(19)
  88#define TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT		16
  89#define TEGRA_APBDMA_AHBSEQ_WRAP_NONE		0
  90
  91/* APB address */
  92#define TEGRA_APBDMA_CHAN_APBPTR		0x018
  93
  94/* APB sequence register */
  95#define TEGRA_APBDMA_CHAN_APBSEQ		0x01c
  96#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8		(0 << 28)
  97#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16	(1 << 28)
  98#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32	(2 << 28)
  99#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64	(3 << 28)
 100#define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_128	(4 << 28)
 101#define TEGRA_APBDMA_APBSEQ_DATA_SWAP		BIT(27)
 102#define TEGRA_APBDMA_APBSEQ_WRAP_WORD_1		(1 << 16)
 103
 104/* Tegra148 specific registers */
 105#define TEGRA_APBDMA_CHAN_WCOUNT		0x20
 106
 107#define TEGRA_APBDMA_CHAN_WORD_TRANSFER		0x24
 108
 109/*
 110 * If any burst is in flight and DMA paused then this is the time to complete
 111 * on-flight burst and update DMA status register.
 112 */
 113#define TEGRA_APBDMA_BURST_COMPLETE_TIME	20
 114
 115/* Channel base address offset from APBDMA base address */
 116#define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET	0x1000
 117
 118#define TEGRA_APBDMA_SLAVE_ID_INVALID	(TEGRA_APBDMA_CSR_REQ_SEL_MASK + 1)
 119
 120struct tegra_dma;
 121
 122/*
 123 * tegra_dma_chip_data Tegra chip specific DMA data
 124 * @nr_channels: Number of channels available in the controller.
 125 * @channel_reg_size: Channel register size/stride.
 126 * @max_dma_count: Maximum DMA transfer count supported by DMA controller.
 127 * @support_channel_pause: Support channel wise pause of dma.
 128 * @support_separate_wcount_reg: Support separate word count register.
 129 */
 130struct tegra_dma_chip_data {
 131	int nr_channels;
 132	int channel_reg_size;
 133	int max_dma_count;
 134	bool support_channel_pause;
 135	bool support_separate_wcount_reg;
 136};
 137
 138/* DMA channel registers */
 139struct tegra_dma_channel_regs {
 140	unsigned long	csr;
 141	unsigned long	ahb_ptr;
 142	unsigned long	apb_ptr;
 143	unsigned long	ahb_seq;
 144	unsigned long	apb_seq;
 145	unsigned long	wcount;
 146};
 147
 148/*
 149 * tegra_dma_sg_req: Dma request details to configure hardware. This
 150 * contains the details for one transfer to configure DMA hw.
 151 * The client's request for data transfer can be broken into multiple
 152 * sub-transfer as per requester details and hw support.
 153 * This sub transfer get added in the list of transfer and point to Tegra
 154 * DMA descriptor which manages the transfer details.
 155 */
 156struct tegra_dma_sg_req {
 157	struct tegra_dma_channel_regs	ch_regs;
 158	int				req_len;
 159	bool				configured;
 160	bool				last_sg;
 161	struct list_head		node;
 162	struct tegra_dma_desc		*dma_desc;
 
 163};
 164
 165/*
 166 * tegra_dma_desc: Tegra DMA descriptors which manages the client requests.
 167 * This descriptor keep track of transfer status, callbacks and request
 168 * counts etc.
 169 */
 170struct tegra_dma_desc {
 171	struct dma_async_tx_descriptor	txd;
 172	int				bytes_requested;
 173	int				bytes_transferred;
 174	enum dma_status			dma_status;
 175	struct list_head		node;
 176	struct list_head		tx_list;
 177	struct list_head		cb_node;
 178	int				cb_count;
 179};
 180
 181struct tegra_dma_channel;
 182
 183typedef void (*dma_isr_handler)(struct tegra_dma_channel *tdc,
 184				bool to_terminate);
 185
 186/* tegra_dma_channel: Channel specific information */
 187struct tegra_dma_channel {
 188	struct dma_chan		dma_chan;
 189	char			name[30];
 190	bool			config_init;
 191	int			id;
 192	int			irq;
 193	void __iomem		*chan_addr;
 194	spinlock_t		lock;
 195	bool			busy;
 196	struct tegra_dma	*tdma;
 197	bool			cyclic;
 198
 199	/* Different lists for managing the requests */
 200	struct list_head	free_sg_req;
 201	struct list_head	pending_sg_req;
 202	struct list_head	free_dma_desc;
 203	struct list_head	cb_desc;
 204
 205	/* ISR handler and tasklet for bottom half of isr handling */
 206	dma_isr_handler		isr_handler;
 207	struct tasklet_struct	tasklet;
 208
 209	/* Channel-slave specific configuration */
 210	unsigned int slave_id;
 211	struct dma_slave_config dma_sconfig;
 212	struct tegra_dma_channel_regs	channel_reg;
 213};
 214
 215/* tegra_dma: Tegra DMA specific information */
 216struct tegra_dma {
 217	struct dma_device		dma_dev;
 218	struct device			*dev;
 219	struct clk			*dma_clk;
 220	struct reset_control		*rst;
 221	spinlock_t			global_lock;
 222	void __iomem			*base_addr;
 223	const struct tegra_dma_chip_data *chip_data;
 224
 225	/*
 226	 * Counter for managing global pausing of the DMA controller.
 227	 * Only applicable for devices that don't support individual
 228	 * channel pausing.
 229	 */
 230	u32				global_pause_count;
 231
 232	/* Some register need to be cache before suspend */
 233	u32				reg_gen;
 234
 235	/* Last member of the structure */
 236	struct tegra_dma_channel channels[0];
 237};
 238
 239static inline void tdma_write(struct tegra_dma *tdma, u32 reg, u32 val)
 240{
 241	writel(val, tdma->base_addr + reg);
 242}
 243
 244static inline u32 tdma_read(struct tegra_dma *tdma, u32 reg)
 245{
 246	return readl(tdma->base_addr + reg);
 247}
 248
 249static inline void tdc_write(struct tegra_dma_channel *tdc,
 250		u32 reg, u32 val)
 251{
 252	writel(val, tdc->chan_addr + reg);
 253}
 254
 255static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
 256{
 257	return readl(tdc->chan_addr + reg);
 258}
 259
 260static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
 261{
 262	return container_of(dc, struct tegra_dma_channel, dma_chan);
 263}
 264
 265static inline struct tegra_dma_desc *txd_to_tegra_dma_desc(
 266		struct dma_async_tx_descriptor *td)
 267{
 268	return container_of(td, struct tegra_dma_desc, txd);
 269}
 270
 271static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
 272{
 273	return &tdc->dma_chan.dev->device;
 274}
 275
 276static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *tx);
 277static int tegra_dma_runtime_suspend(struct device *dev);
 278static int tegra_dma_runtime_resume(struct device *dev);
 279
 280/* Get DMA desc from free list, if not there then allocate it.  */
 281static struct tegra_dma_desc *tegra_dma_desc_get(
 282		struct tegra_dma_channel *tdc)
 283{
 284	struct tegra_dma_desc *dma_desc;
 285	unsigned long flags;
 286
 287	spin_lock_irqsave(&tdc->lock, flags);
 288
 289	/* Do not allocate if desc are waiting for ack */
 290	list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
 291		if (async_tx_test_ack(&dma_desc->txd)) {
 292			list_del(&dma_desc->node);
 293			spin_unlock_irqrestore(&tdc->lock, flags);
 294			dma_desc->txd.flags = 0;
 295			return dma_desc;
 296		}
 297	}
 298
 299	spin_unlock_irqrestore(&tdc->lock, flags);
 300
 301	/* Allocate DMA desc */
 302	dma_desc = kzalloc(sizeof(*dma_desc), GFP_NOWAIT);
 303	if (!dma_desc)
 304		return NULL;
 305
 306	dma_async_tx_descriptor_init(&dma_desc->txd, &tdc->dma_chan);
 307	dma_desc->txd.tx_submit = tegra_dma_tx_submit;
 308	dma_desc->txd.flags = 0;
 309	return dma_desc;
 310}
 311
 312static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
 313		struct tegra_dma_desc *dma_desc)
 314{
 315	unsigned long flags;
 316
 317	spin_lock_irqsave(&tdc->lock, flags);
 318	if (!list_empty(&dma_desc->tx_list))
 319		list_splice_init(&dma_desc->tx_list, &tdc->free_sg_req);
 320	list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 321	spin_unlock_irqrestore(&tdc->lock, flags);
 322}
 323
 324static struct tegra_dma_sg_req *tegra_dma_sg_req_get(
 325		struct tegra_dma_channel *tdc)
 326{
 327	struct tegra_dma_sg_req *sg_req = NULL;
 328	unsigned long flags;
 329
 330	spin_lock_irqsave(&tdc->lock, flags);
 331	if (!list_empty(&tdc->free_sg_req)) {
 332		sg_req = list_first_entry(&tdc->free_sg_req,
 333					typeof(*sg_req), node);
 334		list_del(&sg_req->node);
 335		spin_unlock_irqrestore(&tdc->lock, flags);
 336		return sg_req;
 337	}
 338	spin_unlock_irqrestore(&tdc->lock, flags);
 339
 340	sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_NOWAIT);
 341
 342	return sg_req;
 343}
 344
 345static int tegra_dma_slave_config(struct dma_chan *dc,
 346		struct dma_slave_config *sconfig)
 347{
 348	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 349
 350	if (!list_empty(&tdc->pending_sg_req)) {
 351		dev_err(tdc2dev(tdc), "Configuration not allowed\n");
 352		return -EBUSY;
 353	}
 354
 355	memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
 356	if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID) {
 
 357		if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK)
 358			return -EINVAL;
 359		tdc->slave_id = sconfig->slave_id;
 360	}
 361	tdc->config_init = true;
 362	return 0;
 363}
 364
 365static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
 366	bool wait_for_burst_complete)
 367{
 368	struct tegra_dma *tdma = tdc->tdma;
 369
 370	spin_lock(&tdma->global_lock);
 371
 372	if (tdc->tdma->global_pause_count == 0) {
 373		tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
 374		if (wait_for_burst_complete)
 375			udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 376	}
 377
 378	tdc->tdma->global_pause_count++;
 379
 380	spin_unlock(&tdma->global_lock);
 381}
 382
 383static void tegra_dma_global_resume(struct tegra_dma_channel *tdc)
 384{
 385	struct tegra_dma *tdma = tdc->tdma;
 386
 387	spin_lock(&tdma->global_lock);
 388
 389	if (WARN_ON(tdc->tdma->global_pause_count == 0))
 390		goto out;
 391
 392	if (--tdc->tdma->global_pause_count == 0)
 393		tdma_write(tdma, TEGRA_APBDMA_GENERAL,
 394			   TEGRA_APBDMA_GENERAL_ENABLE);
 395
 396out:
 397	spin_unlock(&tdma->global_lock);
 398}
 399
 400static void tegra_dma_pause(struct tegra_dma_channel *tdc,
 401	bool wait_for_burst_complete)
 402{
 403	struct tegra_dma *tdma = tdc->tdma;
 404
 405	if (tdma->chip_data->support_channel_pause) {
 406		tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE,
 407				TEGRA_APBDMA_CHAN_CSRE_PAUSE);
 408		if (wait_for_burst_complete)
 409			udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 410	} else {
 411		tegra_dma_global_pause(tdc, wait_for_burst_complete);
 412	}
 413}
 414
 415static void tegra_dma_resume(struct tegra_dma_channel *tdc)
 416{
 417	struct tegra_dma *tdma = tdc->tdma;
 418
 419	if (tdma->chip_data->support_channel_pause) {
 420		tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE, 0);
 421	} else {
 422		tegra_dma_global_resume(tdc);
 423	}
 424}
 425
 426static void tegra_dma_stop(struct tegra_dma_channel *tdc)
 427{
 428	u32 csr;
 429	u32 status;
 430
 431	/* Disable interrupts */
 432	csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
 433	csr &= ~TEGRA_APBDMA_CSR_IE_EOC;
 434	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
 435
 436	/* Disable DMA */
 437	csr &= ~TEGRA_APBDMA_CSR_ENB;
 438	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
 439
 440	/* Clear interrupt status if it is there */
 441	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 442	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 443		dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
 444		tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
 445	}
 446	tdc->busy = false;
 447}
 448
 449static void tegra_dma_start(struct tegra_dma_channel *tdc,
 450		struct tegra_dma_sg_req *sg_req)
 451{
 452	struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
 453
 454	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, ch_regs->csr);
 455	tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_regs->apb_seq);
 456	tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_regs->apb_ptr);
 457	tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_regs->ahb_seq);
 458	tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_regs->ahb_ptr);
 459	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 460		tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT, ch_regs->wcount);
 461
 462	/* Start DMA */
 463	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
 464				ch_regs->csr | TEGRA_APBDMA_CSR_ENB);
 465}
 466
 467static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
 468		struct tegra_dma_sg_req *nsg_req)
 469{
 470	unsigned long status;
 471
 472	/*
 473	 * The DMA controller reloads the new configuration for next transfer
 474	 * after last burst of current transfer completes.
 475	 * If there is no IEC status then this makes sure that last burst
 476	 * has not be completed. There may be case that last burst is on
 477	 * flight and so it can complete but because DMA is paused, it
 478	 * will not generates interrupt as well as not reload the new
 479	 * configuration.
 480	 * If there is already IEC status then interrupt handler need to
 481	 * load new configuration.
 482	 */
 483	tegra_dma_pause(tdc, false);
 484	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 485
 486	/*
 487	 * If interrupt is pending then do nothing as the ISR will handle
 488	 * the programing for new request.
 489	 */
 490	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 491		dev_err(tdc2dev(tdc),
 492			"Skipping new configuration as interrupt is pending\n");
 493		tegra_dma_resume(tdc);
 494		return;
 495	}
 496
 497	/* Safe to program new configuration */
 498	tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, nsg_req->ch_regs.apb_ptr);
 499	tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
 500	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 501		tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
 502						nsg_req->ch_regs.wcount);
 503	tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
 504				nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
 505	nsg_req->configured = true;
 
 506
 507	tegra_dma_resume(tdc);
 508}
 509
 510static void tdc_start_head_req(struct tegra_dma_channel *tdc)
 511{
 512	struct tegra_dma_sg_req *sg_req;
 513
 514	if (list_empty(&tdc->pending_sg_req))
 515		return;
 516
 517	sg_req = list_first_entry(&tdc->pending_sg_req,
 518					typeof(*sg_req), node);
 519	tegra_dma_start(tdc, sg_req);
 520	sg_req->configured = true;
 
 521	tdc->busy = true;
 522}
 523
 524static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
 525{
 526	struct tegra_dma_sg_req *hsgreq;
 527	struct tegra_dma_sg_req *hnsgreq;
 528
 529	if (list_empty(&tdc->pending_sg_req))
 530		return;
 531
 532	hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
 533	if (!list_is_last(&hsgreq->node, &tdc->pending_sg_req)) {
 534		hnsgreq = list_first_entry(&hsgreq->node,
 535					typeof(*hnsgreq), node);
 536		tegra_dma_configure_for_next(tdc, hnsgreq);
 537	}
 538}
 539
 540static inline int get_current_xferred_count(struct tegra_dma_channel *tdc,
 541	struct tegra_dma_sg_req *sg_req, unsigned long status)
 542{
 543	return sg_req->req_len - (status & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
 544}
 545
 546static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
 547{
 548	struct tegra_dma_sg_req *sgreq;
 549	struct tegra_dma_desc *dma_desc;
 550
 551	while (!list_empty(&tdc->pending_sg_req)) {
 552		sgreq = list_first_entry(&tdc->pending_sg_req,
 553						typeof(*sgreq), node);
 554		list_move_tail(&sgreq->node, &tdc->free_sg_req);
 555		if (sgreq->last_sg) {
 556			dma_desc = sgreq->dma_desc;
 557			dma_desc->dma_status = DMA_ERROR;
 558			list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 559
 560			/* Add in cb list if it is not there. */
 561			if (!dma_desc->cb_count)
 562				list_add_tail(&dma_desc->cb_node,
 563							&tdc->cb_desc);
 564			dma_desc->cb_count++;
 565		}
 566	}
 567	tdc->isr_handler = NULL;
 568}
 569
 570static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
 571		struct tegra_dma_sg_req *last_sg_req, bool to_terminate)
 572{
 573	struct tegra_dma_sg_req *hsgreq = NULL;
 574
 575	if (list_empty(&tdc->pending_sg_req)) {
 576		dev_err(tdc2dev(tdc), "Dma is running without req\n");
 577		tegra_dma_stop(tdc);
 578		return false;
 579	}
 580
 581	/*
 582	 * Check that head req on list should be in flight.
 583	 * If it is not in flight then abort transfer as
 584	 * looping of transfer can not continue.
 585	 */
 586	hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
 587	if (!hsgreq->configured) {
 588		tegra_dma_stop(tdc);
 589		dev_err(tdc2dev(tdc), "Error in dma transfer, aborting dma\n");
 590		tegra_dma_abort_all(tdc);
 591		return false;
 592	}
 593
 594	/* Configure next request */
 595	if (!to_terminate)
 596		tdc_configure_next_head_desc(tdc);
 597	return true;
 598}
 599
 600static void handle_once_dma_done(struct tegra_dma_channel *tdc,
 601	bool to_terminate)
 602{
 603	struct tegra_dma_sg_req *sgreq;
 604	struct tegra_dma_desc *dma_desc;
 605
 606	tdc->busy = false;
 607	sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
 608	dma_desc = sgreq->dma_desc;
 609	dma_desc->bytes_transferred += sgreq->req_len;
 610
 611	list_del(&sgreq->node);
 612	if (sgreq->last_sg) {
 613		dma_desc->dma_status = DMA_COMPLETE;
 614		dma_cookie_complete(&dma_desc->txd);
 615		if (!dma_desc->cb_count)
 616			list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
 617		dma_desc->cb_count++;
 618		list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 619	}
 620	list_add_tail(&sgreq->node, &tdc->free_sg_req);
 621
 622	/* Do not start DMA if it is going to be terminate */
 623	if (to_terminate || list_empty(&tdc->pending_sg_req))
 624		return;
 625
 626	tdc_start_head_req(tdc);
 627}
 628
 629static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
 630		bool to_terminate)
 631{
 632	struct tegra_dma_sg_req *sgreq;
 633	struct tegra_dma_desc *dma_desc;
 634	bool st;
 635
 636	sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
 637	dma_desc = sgreq->dma_desc;
 638	dma_desc->bytes_transferred += sgreq->req_len;
 
 
 
 639
 640	/* Callback need to be call */
 641	if (!dma_desc->cb_count)
 642		list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
 643	dma_desc->cb_count++;
 644
 
 
 645	/* If not last req then put at end of pending list */
 646	if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
 647		list_move_tail(&sgreq->node, &tdc->pending_sg_req);
 648		sgreq->configured = false;
 649		st = handle_continuous_head_request(tdc, sgreq, to_terminate);
 650		if (!st)
 651			dma_desc->dma_status = DMA_ERROR;
 652	}
 653}
 654
 655static void tegra_dma_tasklet(unsigned long data)
 656{
 657	struct tegra_dma_channel *tdc = (struct tegra_dma_channel *)data;
 658	struct dmaengine_desc_callback cb;
 659	struct tegra_dma_desc *dma_desc;
 660	unsigned long flags;
 661	int cb_count;
 662
 663	spin_lock_irqsave(&tdc->lock, flags);
 664	while (!list_empty(&tdc->cb_desc)) {
 665		dma_desc  = list_first_entry(&tdc->cb_desc,
 666					typeof(*dma_desc), cb_node);
 667		list_del(&dma_desc->cb_node);
 668		dmaengine_desc_get_callback(&dma_desc->txd, &cb);
 669		cb_count = dma_desc->cb_count;
 670		dma_desc->cb_count = 0;
 
 
 671		spin_unlock_irqrestore(&tdc->lock, flags);
 672		while (cb_count--)
 673			dmaengine_desc_callback_invoke(&cb, NULL);
 674		spin_lock_irqsave(&tdc->lock, flags);
 675	}
 676	spin_unlock_irqrestore(&tdc->lock, flags);
 677}
 678
 679static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
 680{
 681	struct tegra_dma_channel *tdc = dev_id;
 682	unsigned long status;
 683	unsigned long flags;
 684
 685	spin_lock_irqsave(&tdc->lock, flags);
 686
 
 687	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 688	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 689		tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
 690		tdc->isr_handler(tdc, false);
 691		tasklet_schedule(&tdc->tasklet);
 692		spin_unlock_irqrestore(&tdc->lock, flags);
 693		return IRQ_HANDLED;
 694	}
 695
 696	spin_unlock_irqrestore(&tdc->lock, flags);
 697	dev_info(tdc2dev(tdc),
 698		"Interrupt already served status 0x%08lx\n", status);
 699	return IRQ_NONE;
 700}
 701
 702static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *txd)
 703{
 704	struct tegra_dma_desc *dma_desc = txd_to_tegra_dma_desc(txd);
 705	struct tegra_dma_channel *tdc = to_tegra_dma_chan(txd->chan);
 706	unsigned long flags;
 707	dma_cookie_t cookie;
 708
 709	spin_lock_irqsave(&tdc->lock, flags);
 710	dma_desc->dma_status = DMA_IN_PROGRESS;
 711	cookie = dma_cookie_assign(&dma_desc->txd);
 712	list_splice_tail_init(&dma_desc->tx_list, &tdc->pending_sg_req);
 713	spin_unlock_irqrestore(&tdc->lock, flags);
 714	return cookie;
 715}
 716
 717static void tegra_dma_issue_pending(struct dma_chan *dc)
 718{
 719	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 720	unsigned long flags;
 721
 722	spin_lock_irqsave(&tdc->lock, flags);
 723	if (list_empty(&tdc->pending_sg_req)) {
 724		dev_err(tdc2dev(tdc), "No DMA request\n");
 725		goto end;
 726	}
 727	if (!tdc->busy) {
 728		tdc_start_head_req(tdc);
 729
 730		/* Continuous single mode: Configure next req */
 731		if (tdc->cyclic) {
 732			/*
 733			 * Wait for 1 burst time for configure DMA for
 734			 * next transfer.
 735			 */
 736			udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 737			tdc_configure_next_head_desc(tdc);
 738		}
 739	}
 740end:
 741	spin_unlock_irqrestore(&tdc->lock, flags);
 742}
 743
 744static int tegra_dma_terminate_all(struct dma_chan *dc)
 745{
 746	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 747	struct tegra_dma_sg_req *sgreq;
 748	struct tegra_dma_desc *dma_desc;
 749	unsigned long flags;
 750	unsigned long status;
 751	unsigned long wcount;
 752	bool was_busy;
 753
 754	spin_lock_irqsave(&tdc->lock, flags);
 755	if (list_empty(&tdc->pending_sg_req)) {
 756		spin_unlock_irqrestore(&tdc->lock, flags);
 757		return 0;
 758	}
 759
 760	if (!tdc->busy)
 761		goto skip_dma_stop;
 762
 763	/* Pause DMA before checking the queue status */
 764	tegra_dma_pause(tdc, true);
 765
 766	status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 767	if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 768		dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
 769		tdc->isr_handler(tdc, true);
 770		status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 771	}
 772	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 773		wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
 774	else
 775		wcount = status;
 776
 777	was_busy = tdc->busy;
 778	tegra_dma_stop(tdc);
 779
 780	if (!list_empty(&tdc->pending_sg_req) && was_busy) {
 781		sgreq = list_first_entry(&tdc->pending_sg_req,
 782					typeof(*sgreq), node);
 783		sgreq->dma_desc->bytes_transferred +=
 784				get_current_xferred_count(tdc, sgreq, wcount);
 785	}
 786	tegra_dma_resume(tdc);
 787
 788skip_dma_stop:
 789	tegra_dma_abort_all(tdc);
 790
 791	while (!list_empty(&tdc->cb_desc)) {
 792		dma_desc  = list_first_entry(&tdc->cb_desc,
 793					typeof(*dma_desc), cb_node);
 794		list_del(&dma_desc->cb_node);
 795		dma_desc->cb_count = 0;
 796	}
 797	spin_unlock_irqrestore(&tdc->lock, flags);
 798	return 0;
 799}
 800
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 801static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
 802	dma_cookie_t cookie, struct dma_tx_state *txstate)
 803{
 804	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 805	struct tegra_dma_desc *dma_desc;
 806	struct tegra_dma_sg_req *sg_req;
 807	enum dma_status ret;
 808	unsigned long flags;
 809	unsigned int residual;
 
 810
 811	ret = dma_cookie_status(dc, cookie, txstate);
 812	if (ret == DMA_COMPLETE)
 813		return ret;
 814
 815	spin_lock_irqsave(&tdc->lock, flags);
 816
 817	/* Check on wait_ack desc status */
 818	list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
 819		if (dma_desc->txd.cookie == cookie) {
 820			ret = dma_desc->dma_status;
 821			goto found;
 822		}
 823	}
 824
 825	/* Check in pending list */
 826	list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
 827		dma_desc = sg_req->dma_desc;
 828		if (dma_desc->txd.cookie == cookie) {
 
 829			ret = dma_desc->dma_status;
 830			goto found;
 831		}
 832	}
 833
 834	dev_dbg(tdc2dev(tdc), "cookie %d not found\n", cookie);
 835	dma_desc = NULL;
 836
 837found:
 838	if (dma_desc && txstate) {
 839		residual = dma_desc->bytes_requested -
 840			   (dma_desc->bytes_transferred %
 841			    dma_desc->bytes_requested);
 842		dma_set_residue(txstate, residual);
 843	}
 844
 
 845	spin_unlock_irqrestore(&tdc->lock, flags);
 846	return ret;
 847}
 848
 849static inline int get_bus_width(struct tegra_dma_channel *tdc,
 850		enum dma_slave_buswidth slave_bw)
 851{
 852	switch (slave_bw) {
 853	case DMA_SLAVE_BUSWIDTH_1_BYTE:
 854		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8;
 855	case DMA_SLAVE_BUSWIDTH_2_BYTES:
 856		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16;
 857	case DMA_SLAVE_BUSWIDTH_4_BYTES:
 858		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
 859	case DMA_SLAVE_BUSWIDTH_8_BYTES:
 860		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64;
 861	default:
 862		dev_warn(tdc2dev(tdc),
 863			"slave bw is not supported, using 32bits\n");
 864		return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
 865	}
 866}
 867
 868static inline int get_burst_size(struct tegra_dma_channel *tdc,
 869	u32 burst_size, enum dma_slave_buswidth slave_bw, int len)
 870{
 871	int burst_byte;
 872	int burst_ahb_width;
 873
 874	/*
 875	 * burst_size from client is in terms of the bus_width.
 876	 * convert them into AHB memory width which is 4 byte.
 877	 */
 878	burst_byte = burst_size * slave_bw;
 879	burst_ahb_width = burst_byte / 4;
 880
 881	/* If burst size is 0 then calculate the burst size based on length */
 882	if (!burst_ahb_width) {
 883		if (len & 0xF)
 884			return TEGRA_APBDMA_AHBSEQ_BURST_1;
 885		else if ((len >> 4) & 0x1)
 886			return TEGRA_APBDMA_AHBSEQ_BURST_4;
 887		else
 888			return TEGRA_APBDMA_AHBSEQ_BURST_8;
 889	}
 890	if (burst_ahb_width < 4)
 891		return TEGRA_APBDMA_AHBSEQ_BURST_1;
 892	else if (burst_ahb_width < 8)
 893		return TEGRA_APBDMA_AHBSEQ_BURST_4;
 894	else
 895		return TEGRA_APBDMA_AHBSEQ_BURST_8;
 896}
 897
 898static int get_transfer_param(struct tegra_dma_channel *tdc,
 899	enum dma_transfer_direction direction, unsigned long *apb_addr,
 900	unsigned long *apb_seq,	unsigned long *csr, unsigned int *burst_size,
 901	enum dma_slave_buswidth *slave_bw)
 902{
 903	switch (direction) {
 904	case DMA_MEM_TO_DEV:
 905		*apb_addr = tdc->dma_sconfig.dst_addr;
 906		*apb_seq = get_bus_width(tdc, tdc->dma_sconfig.dst_addr_width);
 907		*burst_size = tdc->dma_sconfig.dst_maxburst;
 908		*slave_bw = tdc->dma_sconfig.dst_addr_width;
 909		*csr = TEGRA_APBDMA_CSR_DIR;
 910		return 0;
 911
 912	case DMA_DEV_TO_MEM:
 913		*apb_addr = tdc->dma_sconfig.src_addr;
 914		*apb_seq = get_bus_width(tdc, tdc->dma_sconfig.src_addr_width);
 915		*burst_size = tdc->dma_sconfig.src_maxburst;
 916		*slave_bw = tdc->dma_sconfig.src_addr_width;
 917		*csr = 0;
 918		return 0;
 919
 920	default:
 921		dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
 922		return -EINVAL;
 923	}
 924	return -EINVAL;
 925}
 926
 927static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
 928	struct tegra_dma_channel_regs *ch_regs, u32 len)
 929{
 930	u32 len_field = (len - 4) & 0xFFFC;
 931
 932	if (tdc->tdma->chip_data->support_separate_wcount_reg)
 933		ch_regs->wcount = len_field;
 934	else
 935		ch_regs->csr |= len_field;
 936}
 937
 938static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
 939	struct dma_chan *dc, struct scatterlist *sgl, unsigned int sg_len,
 940	enum dma_transfer_direction direction, unsigned long flags,
 941	void *context)
 942{
 943	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 944	struct tegra_dma_desc *dma_desc;
 945	unsigned int i;
 946	struct scatterlist *sg;
 947	unsigned long csr, ahb_seq, apb_ptr, apb_seq;
 948	struct list_head req_list;
 949	struct tegra_dma_sg_req  *sg_req = NULL;
 950	u32 burst_size;
 951	enum dma_slave_buswidth slave_bw;
 952
 953	if (!tdc->config_init) {
 954		dev_err(tdc2dev(tdc), "dma channel is not configured\n");
 955		return NULL;
 956	}
 957	if (sg_len < 1) {
 958		dev_err(tdc2dev(tdc), "Invalid segment length %d\n", sg_len);
 959		return NULL;
 960	}
 961
 962	if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
 963				&burst_size, &slave_bw) < 0)
 964		return NULL;
 965
 966	INIT_LIST_HEAD(&req_list);
 967
 968	ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
 969	ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
 970					TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
 971	ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
 972
 973	csr |= TEGRA_APBDMA_CSR_ONCE | TEGRA_APBDMA_CSR_FLOW;
 974	csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
 975	if (flags & DMA_PREP_INTERRUPT)
 
 
 
 
 
 976		csr |= TEGRA_APBDMA_CSR_IE_EOC;
 
 
 
 
 977
 978	apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
 979
 980	dma_desc = tegra_dma_desc_get(tdc);
 981	if (!dma_desc) {
 982		dev_err(tdc2dev(tdc), "Dma descriptors not available\n");
 983		return NULL;
 984	}
 985	INIT_LIST_HEAD(&dma_desc->tx_list);
 986	INIT_LIST_HEAD(&dma_desc->cb_node);
 987	dma_desc->cb_count = 0;
 988	dma_desc->bytes_requested = 0;
 989	dma_desc->bytes_transferred = 0;
 990	dma_desc->dma_status = DMA_IN_PROGRESS;
 991
 992	/* Make transfer requests */
 993	for_each_sg(sgl, sg, sg_len, i) {
 994		u32 len, mem;
 995
 996		mem = sg_dma_address(sg);
 997		len = sg_dma_len(sg);
 998
 999		if ((len & 3) || (mem & 3) ||
1000				(len > tdc->tdma->chip_data->max_dma_count)) {
1001			dev_err(tdc2dev(tdc),
1002				"Dma length/memory address is not supported\n");
1003			tegra_dma_desc_put(tdc, dma_desc);
1004			return NULL;
1005		}
1006
1007		sg_req = tegra_dma_sg_req_get(tdc);
1008		if (!sg_req) {
1009			dev_err(tdc2dev(tdc), "Dma sg-req not available\n");
1010			tegra_dma_desc_put(tdc, dma_desc);
1011			return NULL;
1012		}
1013
1014		ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1015		dma_desc->bytes_requested += len;
1016
1017		sg_req->ch_regs.apb_ptr = apb_ptr;
1018		sg_req->ch_regs.ahb_ptr = mem;
1019		sg_req->ch_regs.csr = csr;
1020		tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1021		sg_req->ch_regs.apb_seq = apb_seq;
1022		sg_req->ch_regs.ahb_seq = ahb_seq;
1023		sg_req->configured = false;
1024		sg_req->last_sg = false;
1025		sg_req->dma_desc = dma_desc;
1026		sg_req->req_len = len;
1027
1028		list_add_tail(&sg_req->node, &dma_desc->tx_list);
1029	}
1030	sg_req->last_sg = true;
1031	if (flags & DMA_CTRL_ACK)
1032		dma_desc->txd.flags = DMA_CTRL_ACK;
1033
1034	/*
1035	 * Make sure that mode should not be conflicting with currently
1036	 * configured mode.
1037	 */
1038	if (!tdc->isr_handler) {
1039		tdc->isr_handler = handle_once_dma_done;
1040		tdc->cyclic = false;
1041	} else {
1042		if (tdc->cyclic) {
1043			dev_err(tdc2dev(tdc), "DMA configured in cyclic mode\n");
1044			tegra_dma_desc_put(tdc, dma_desc);
1045			return NULL;
1046		}
1047	}
1048
1049	return &dma_desc->txd;
1050}
1051
1052static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
1053	struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
1054	size_t period_len, enum dma_transfer_direction direction,
1055	unsigned long flags)
1056{
1057	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1058	struct tegra_dma_desc *dma_desc = NULL;
1059	struct tegra_dma_sg_req *sg_req = NULL;
1060	unsigned long csr, ahb_seq, apb_ptr, apb_seq;
1061	int len;
1062	size_t remain_len;
1063	dma_addr_t mem = buf_addr;
1064	u32 burst_size;
1065	enum dma_slave_buswidth slave_bw;
1066
1067	if (!buf_len || !period_len) {
1068		dev_err(tdc2dev(tdc), "Invalid buffer/period len\n");
1069		return NULL;
1070	}
1071
1072	if (!tdc->config_init) {
1073		dev_err(tdc2dev(tdc), "DMA slave is not configured\n");
1074		return NULL;
1075	}
1076
1077	/*
1078	 * We allow to take more number of requests till DMA is
1079	 * not started. The driver will loop over all requests.
1080	 * Once DMA is started then new requests can be queued only after
1081	 * terminating the DMA.
1082	 */
1083	if (tdc->busy) {
1084		dev_err(tdc2dev(tdc), "Request not allowed when dma running\n");
1085		return NULL;
1086	}
1087
1088	/*
1089	 * We only support cycle transfer when buf_len is multiple of
1090	 * period_len.
1091	 */
1092	if (buf_len % period_len) {
1093		dev_err(tdc2dev(tdc), "buf_len is not multiple of period_len\n");
1094		return NULL;
1095	}
1096
1097	len = period_len;
1098	if ((len & 3) || (buf_addr & 3) ||
1099			(len > tdc->tdma->chip_data->max_dma_count)) {
1100		dev_err(tdc2dev(tdc), "Req len/mem address is not correct\n");
1101		return NULL;
1102	}
1103
1104	if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
1105				&burst_size, &slave_bw) < 0)
1106		return NULL;
1107
1108	ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
1109	ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
1110					TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
1111	ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
1112
1113	csr |= TEGRA_APBDMA_CSR_FLOW;
1114	if (flags & DMA_PREP_INTERRUPT)
 
 
 
 
1115		csr |= TEGRA_APBDMA_CSR_IE_EOC;
1116	csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
 
 
 
1117
1118	apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
1119
1120	dma_desc = tegra_dma_desc_get(tdc);
1121	if (!dma_desc) {
1122		dev_err(tdc2dev(tdc), "not enough descriptors available\n");
1123		return NULL;
1124	}
1125
1126	INIT_LIST_HEAD(&dma_desc->tx_list);
1127	INIT_LIST_HEAD(&dma_desc->cb_node);
1128	dma_desc->cb_count = 0;
1129
1130	dma_desc->bytes_transferred = 0;
1131	dma_desc->bytes_requested = buf_len;
1132	remain_len = buf_len;
1133
1134	/* Split transfer equal to period size */
1135	while (remain_len) {
1136		sg_req = tegra_dma_sg_req_get(tdc);
1137		if (!sg_req) {
1138			dev_err(tdc2dev(tdc), "Dma sg-req not available\n");
1139			tegra_dma_desc_put(tdc, dma_desc);
1140			return NULL;
1141		}
1142
1143		ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1144		sg_req->ch_regs.apb_ptr = apb_ptr;
1145		sg_req->ch_regs.ahb_ptr = mem;
1146		sg_req->ch_regs.csr = csr;
1147		tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1148		sg_req->ch_regs.apb_seq = apb_seq;
1149		sg_req->ch_regs.ahb_seq = ahb_seq;
1150		sg_req->configured = false;
1151		sg_req->last_sg = false;
1152		sg_req->dma_desc = dma_desc;
1153		sg_req->req_len = len;
1154
1155		list_add_tail(&sg_req->node, &dma_desc->tx_list);
1156		remain_len -= len;
1157		mem += len;
1158	}
1159	sg_req->last_sg = true;
1160	if (flags & DMA_CTRL_ACK)
1161		dma_desc->txd.flags = DMA_CTRL_ACK;
1162
1163	/*
1164	 * Make sure that mode should not be conflicting with currently
1165	 * configured mode.
1166	 */
1167	if (!tdc->isr_handler) {
1168		tdc->isr_handler = handle_cont_sngl_cycle_dma_done;
1169		tdc->cyclic = true;
1170	} else {
1171		if (!tdc->cyclic) {
1172			dev_err(tdc2dev(tdc), "DMA configuration conflict\n");
1173			tegra_dma_desc_put(tdc, dma_desc);
1174			return NULL;
1175		}
1176	}
1177
1178	return &dma_desc->txd;
1179}
1180
1181static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
1182{
1183	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1184	struct tegra_dma *tdma = tdc->tdma;
1185	int ret;
1186
1187	dma_cookie_init(&tdc->dma_chan);
1188	tdc->config_init = false;
1189
1190	ret = pm_runtime_get_sync(tdma->dev);
1191	if (ret < 0)
1192		return ret;
1193
1194	return 0;
1195}
1196
1197static void tegra_dma_free_chan_resources(struct dma_chan *dc)
1198{
1199	struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1200	struct tegra_dma *tdma = tdc->tdma;
1201	struct tegra_dma_desc *dma_desc;
1202	struct tegra_dma_sg_req *sg_req;
1203	struct list_head dma_desc_list;
1204	struct list_head sg_req_list;
1205	unsigned long flags;
1206
1207	INIT_LIST_HEAD(&dma_desc_list);
1208	INIT_LIST_HEAD(&sg_req_list);
1209
1210	dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
1211
1212	if (tdc->busy)
1213		tegra_dma_terminate_all(dc);
1214
1215	spin_lock_irqsave(&tdc->lock, flags);
1216	list_splice_init(&tdc->pending_sg_req, &sg_req_list);
1217	list_splice_init(&tdc->free_sg_req, &sg_req_list);
1218	list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
1219	INIT_LIST_HEAD(&tdc->cb_desc);
1220	tdc->config_init = false;
1221	tdc->isr_handler = NULL;
1222	spin_unlock_irqrestore(&tdc->lock, flags);
1223
1224	while (!list_empty(&dma_desc_list)) {
1225		dma_desc = list_first_entry(&dma_desc_list,
1226					typeof(*dma_desc), node);
1227		list_del(&dma_desc->node);
1228		kfree(dma_desc);
1229	}
1230
1231	while (!list_empty(&sg_req_list)) {
1232		sg_req = list_first_entry(&sg_req_list, typeof(*sg_req), node);
1233		list_del(&sg_req->node);
1234		kfree(sg_req);
1235	}
1236	pm_runtime_put(tdma->dev);
1237
1238	tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1239}
1240
1241static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
1242					   struct of_dma *ofdma)
1243{
1244	struct tegra_dma *tdma = ofdma->of_dma_data;
1245	struct dma_chan *chan;
1246	struct tegra_dma_channel *tdc;
1247
1248	if (dma_spec->args[0] > TEGRA_APBDMA_CSR_REQ_SEL_MASK) {
1249		dev_err(tdma->dev, "Invalid slave id: %d\n", dma_spec->args[0]);
1250		return NULL;
1251	}
1252
1253	chan = dma_get_any_slave_channel(&tdma->dma_dev);
1254	if (!chan)
1255		return NULL;
1256
1257	tdc = to_tegra_dma_chan(chan);
1258	tdc->slave_id = dma_spec->args[0];
1259
1260	return chan;
1261}
1262
1263/* Tegra20 specific DMA controller information */
1264static const struct tegra_dma_chip_data tegra20_dma_chip_data = {
1265	.nr_channels		= 16,
1266	.channel_reg_size	= 0x20,
1267	.max_dma_count		= 1024UL * 64,
1268	.support_channel_pause	= false,
1269	.support_separate_wcount_reg = false,
1270};
1271
1272/* Tegra30 specific DMA controller information */
1273static const struct tegra_dma_chip_data tegra30_dma_chip_data = {
1274	.nr_channels		= 32,
1275	.channel_reg_size	= 0x20,
1276	.max_dma_count		= 1024UL * 64,
1277	.support_channel_pause	= false,
1278	.support_separate_wcount_reg = false,
1279};
1280
1281/* Tegra114 specific DMA controller information */
1282static const struct tegra_dma_chip_data tegra114_dma_chip_data = {
1283	.nr_channels		= 32,
1284	.channel_reg_size	= 0x20,
1285	.max_dma_count		= 1024UL * 64,
1286	.support_channel_pause	= true,
1287	.support_separate_wcount_reg = false,
1288};
1289
1290/* Tegra148 specific DMA controller information */
1291static const struct tegra_dma_chip_data tegra148_dma_chip_data = {
1292	.nr_channels		= 32,
1293	.channel_reg_size	= 0x40,
1294	.max_dma_count		= 1024UL * 64,
1295	.support_channel_pause	= true,
1296	.support_separate_wcount_reg = true,
1297};
1298
1299static int tegra_dma_probe(struct platform_device *pdev)
1300{
1301	struct resource *res;
1302	struct tegra_dma *tdma;
1303	int ret;
1304	int i;
1305	const struct tegra_dma_chip_data *cdata;
1306
1307	cdata = of_device_get_match_data(&pdev->dev);
1308	if (!cdata) {
1309		dev_err(&pdev->dev, "Error: No device match data found\n");
1310		return -ENODEV;
1311	}
1312
1313	tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma) + cdata->nr_channels *
1314			sizeof(struct tegra_dma_channel), GFP_KERNEL);
 
1315	if (!tdma)
1316		return -ENOMEM;
1317
1318	tdma->dev = &pdev->dev;
1319	tdma->chip_data = cdata;
1320	platform_set_drvdata(pdev, tdma);
1321
1322	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1323	tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
1324	if (IS_ERR(tdma->base_addr))
1325		return PTR_ERR(tdma->base_addr);
1326
1327	tdma->dma_clk = devm_clk_get(&pdev->dev, NULL);
1328	if (IS_ERR(tdma->dma_clk)) {
1329		dev_err(&pdev->dev, "Error: Missing controller clock\n");
1330		return PTR_ERR(tdma->dma_clk);
1331	}
1332
1333	tdma->rst = devm_reset_control_get(&pdev->dev, "dma");
1334	if (IS_ERR(tdma->rst)) {
1335		dev_err(&pdev->dev, "Error: Missing reset\n");
1336		return PTR_ERR(tdma->rst);
1337	}
1338
1339	spin_lock_init(&tdma->global_lock);
1340
1341	pm_runtime_enable(&pdev->dev);
1342	if (!pm_runtime_enabled(&pdev->dev))
1343		ret = tegra_dma_runtime_resume(&pdev->dev);
1344	else
1345		ret = pm_runtime_get_sync(&pdev->dev);
1346
1347	if (ret < 0) {
1348		pm_runtime_disable(&pdev->dev);
1349		return ret;
1350	}
1351
1352	/* Reset DMA controller */
1353	reset_control_assert(tdma->rst);
1354	udelay(2);
1355	reset_control_deassert(tdma->rst);
1356
1357	/* Enable global DMA registers */
1358	tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
1359	tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1360	tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
1361
1362	pm_runtime_put(&pdev->dev);
1363
1364	INIT_LIST_HEAD(&tdma->dma_dev.channels);
1365	for (i = 0; i < cdata->nr_channels; i++) {
1366		struct tegra_dma_channel *tdc = &tdma->channels[i];
1367
1368		tdc->chan_addr = tdma->base_addr +
1369				 TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET +
1370				 (i * cdata->channel_reg_size);
1371
1372		res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1373		if (!res) {
1374			ret = -EINVAL;
1375			dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1376			goto err_irq;
1377		}
1378		tdc->irq = res->start;
1379		snprintf(tdc->name, sizeof(tdc->name), "apbdma.%d", i);
1380		ret = request_irq(tdc->irq, tegra_dma_isr, 0, tdc->name, tdc);
1381		if (ret) {
1382			dev_err(&pdev->dev,
1383				"request_irq failed with err %d channel %d\n",
1384				ret, i);
1385			goto err_irq;
1386		}
1387
1388		tdc->dma_chan.device = &tdma->dma_dev;
1389		dma_cookie_init(&tdc->dma_chan);
1390		list_add_tail(&tdc->dma_chan.device_node,
1391				&tdma->dma_dev.channels);
1392		tdc->tdma = tdma;
1393		tdc->id = i;
1394		tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1395
1396		tasklet_init(&tdc->tasklet, tegra_dma_tasklet,
1397				(unsigned long)tdc);
1398		spin_lock_init(&tdc->lock);
1399
1400		INIT_LIST_HEAD(&tdc->pending_sg_req);
1401		INIT_LIST_HEAD(&tdc->free_sg_req);
1402		INIT_LIST_HEAD(&tdc->free_dma_desc);
1403		INIT_LIST_HEAD(&tdc->cb_desc);
1404	}
1405
1406	dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
1407	dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
1408	dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
1409
1410	tdma->global_pause_count = 0;
1411	tdma->dma_dev.dev = &pdev->dev;
1412	tdma->dma_dev.device_alloc_chan_resources =
1413					tegra_dma_alloc_chan_resources;
1414	tdma->dma_dev.device_free_chan_resources =
1415					tegra_dma_free_chan_resources;
1416	tdma->dma_dev.device_prep_slave_sg = tegra_dma_prep_slave_sg;
1417	tdma->dma_dev.device_prep_dma_cyclic = tegra_dma_prep_dma_cyclic;
1418	tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1419		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1420		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1421		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1422	tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1423		BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1424		BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1425		BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1426	tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1427	/*
1428	 * XXX The hardware appears to support
1429	 * DMA_RESIDUE_GRANULARITY_BURST-level reporting, but it's
1430	 * only used by this driver during tegra_dma_terminate_all()
1431	 */
1432	tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1433	tdma->dma_dev.device_config = tegra_dma_slave_config;
1434	tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
1435	tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
1436	tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
1437
1438	ret = dma_async_device_register(&tdma->dma_dev);
1439	if (ret < 0) {
1440		dev_err(&pdev->dev,
1441			"Tegra20 APB DMA driver registration failed %d\n", ret);
1442		goto err_irq;
1443	}
1444
1445	ret = of_dma_controller_register(pdev->dev.of_node,
1446					 tegra_dma_of_xlate, tdma);
1447	if (ret < 0) {
1448		dev_err(&pdev->dev,
1449			"Tegra20 APB DMA OF registration failed %d\n", ret);
1450		goto err_unregister_dma_dev;
1451	}
1452
1453	dev_info(&pdev->dev, "Tegra20 APB DMA driver register %d channels\n",
1454			cdata->nr_channels);
1455	return 0;
1456
1457err_unregister_dma_dev:
1458	dma_async_device_unregister(&tdma->dma_dev);
1459err_irq:
1460	while (--i >= 0) {
1461		struct tegra_dma_channel *tdc = &tdma->channels[i];
1462
1463		free_irq(tdc->irq, tdc);
1464		tasklet_kill(&tdc->tasklet);
1465	}
1466
1467	pm_runtime_disable(&pdev->dev);
1468	if (!pm_runtime_status_suspended(&pdev->dev))
1469		tegra_dma_runtime_suspend(&pdev->dev);
1470	return ret;
1471}
1472
1473static int tegra_dma_remove(struct platform_device *pdev)
1474{
1475	struct tegra_dma *tdma = platform_get_drvdata(pdev);
1476	int i;
1477	struct tegra_dma_channel *tdc;
1478
1479	dma_async_device_unregister(&tdma->dma_dev);
1480
1481	for (i = 0; i < tdma->chip_data->nr_channels; ++i) {
1482		tdc = &tdma->channels[i];
1483		free_irq(tdc->irq, tdc);
1484		tasklet_kill(&tdc->tasklet);
1485	}
1486
1487	pm_runtime_disable(&pdev->dev);
1488	if (!pm_runtime_status_suspended(&pdev->dev))
1489		tegra_dma_runtime_suspend(&pdev->dev);
1490
1491	return 0;
1492}
1493
1494static int tegra_dma_runtime_suspend(struct device *dev)
1495{
1496	struct tegra_dma *tdma = dev_get_drvdata(dev);
1497
1498	clk_disable_unprepare(tdma->dma_clk);
1499	return 0;
1500}
1501
1502static int tegra_dma_runtime_resume(struct device *dev)
1503{
1504	struct tegra_dma *tdma = dev_get_drvdata(dev);
1505	int ret;
1506
1507	ret = clk_prepare_enable(tdma->dma_clk);
1508	if (ret < 0) {
1509		dev_err(dev, "clk_enable failed: %d\n", ret);
1510		return ret;
1511	}
1512	return 0;
1513}
1514
1515#ifdef CONFIG_PM_SLEEP
1516static int tegra_dma_pm_suspend(struct device *dev)
1517{
1518	struct tegra_dma *tdma = dev_get_drvdata(dev);
1519	int i;
1520	int ret;
1521
1522	/* Enable clock before accessing register */
1523	ret = pm_runtime_get_sync(dev);
1524	if (ret < 0)
1525		return ret;
1526
1527	tdma->reg_gen = tdma_read(tdma, TEGRA_APBDMA_GENERAL);
1528	for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1529		struct tegra_dma_channel *tdc = &tdma->channels[i];
1530		struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
1531
1532		/* Only save the state of DMA channels that are in use */
1533		if (!tdc->config_init)
1534			continue;
1535
1536		ch_reg->csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
1537		ch_reg->ahb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBPTR);
1538		ch_reg->apb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBPTR);
1539		ch_reg->ahb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBSEQ);
1540		ch_reg->apb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBSEQ);
1541		if (tdma->chip_data->support_separate_wcount_reg)
1542			ch_reg->wcount = tdc_read(tdc,
1543						  TEGRA_APBDMA_CHAN_WCOUNT);
1544	}
1545
1546	/* Disable clock */
1547	pm_runtime_put(dev);
1548	return 0;
1549}
1550
1551static int tegra_dma_pm_resume(struct device *dev)
1552{
1553	struct tegra_dma *tdma = dev_get_drvdata(dev);
1554	int i;
1555	int ret;
1556
1557	/* Enable clock before accessing register */
1558	ret = pm_runtime_get_sync(dev);
1559	if (ret < 0)
1560		return ret;
 
1561
1562	tdma_write(tdma, TEGRA_APBDMA_GENERAL, tdma->reg_gen);
1563	tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1564	tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
1565
1566	for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1567		struct tegra_dma_channel *tdc = &tdma->channels[i];
1568		struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
1569
1570		/* Only restore the state of DMA channels that are in use */
1571		if (!tdc->config_init)
1572			continue;
1573
1574		if (tdma->chip_data->support_separate_wcount_reg)
1575			tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
1576				  ch_reg->wcount);
1577		tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_reg->apb_seq);
1578		tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_reg->apb_ptr);
1579		tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_reg->ahb_seq);
1580		tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_reg->ahb_ptr);
1581		tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
1582			(ch_reg->csr & ~TEGRA_APBDMA_CSR_ENB));
1583	}
1584
1585	/* Disable clock */
1586	pm_runtime_put(dev);
1587	return 0;
1588}
1589#endif
1590
1591static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
1592	SET_RUNTIME_PM_OPS(tegra_dma_runtime_suspend, tegra_dma_runtime_resume,
1593			   NULL)
1594	SET_SYSTEM_SLEEP_PM_OPS(tegra_dma_pm_suspend, tegra_dma_pm_resume)
 
1595};
1596
1597static const struct of_device_id tegra_dma_of_match[] = {
1598	{
1599		.compatible = "nvidia,tegra148-apbdma",
1600		.data = &tegra148_dma_chip_data,
1601	}, {
1602		.compatible = "nvidia,tegra114-apbdma",
1603		.data = &tegra114_dma_chip_data,
1604	}, {
1605		.compatible = "nvidia,tegra30-apbdma",
1606		.data = &tegra30_dma_chip_data,
1607	}, {
1608		.compatible = "nvidia,tegra20-apbdma",
1609		.data = &tegra20_dma_chip_data,
1610	}, {
1611	},
1612};
1613MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
1614
1615static struct platform_driver tegra_dmac_driver = {
1616	.driver = {
1617		.name	= "tegra-apbdma",
1618		.pm	= &tegra_dma_dev_pm_ops,
1619		.of_match_table = tegra_dma_of_match,
1620	},
1621	.probe		= tegra_dma_probe,
1622	.remove		= tegra_dma_remove,
1623};
1624
1625module_platform_driver(tegra_dmac_driver);
1626
1627MODULE_ALIAS("platform:tegra20-apbdma");
1628MODULE_DESCRIPTION("NVIDIA Tegra APB DMA Controller driver");
1629MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1630MODULE_LICENSE("GPL v2");