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_dma.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/reset.h>
25 #include <linux/slab.h>
26 #include <linux/wait.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 BIT(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
112 struct 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 */
122 struct tegra_dma_chip_data {
123 unsigned int nr_channels;
124 unsigned int channel_reg_size;
125 unsigned int max_dma_count;
126 bool support_channel_pause;
127 bool support_separate_wcount_reg;
128 };
129
130 /* DMA channel registers */
131 struct tegra_dma_channel_regs {
132 u32 csr;
133 u32 ahb_ptr;
134 u32 apb_ptr;
135 u32 ahb_seq;
136 u32 apb_seq;
137 u32 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 */
148 struct 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 */
163 struct 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 unsigned int cb_count;
172 };
173
174 struct tegra_dma_channel;
175
176 typedef void (*dma_isr_handler)(struct tegra_dma_channel *tdc,
177 bool to_terminate);
178
179 /* tegra_dma_channel: Channel specific information */
180 struct tegra_dma_channel {
181 struct dma_chan dma_chan;
182 char name[12];
183 bool config_init;
184 unsigned int id;
185 void __iomem *chan_addr;
186 spinlock_t lock;
187 bool busy;
188 struct tegra_dma *tdma;
189 bool cyclic;
190
191 /* Different lists for managing the requests */
192 struct list_head free_sg_req;
193 struct list_head pending_sg_req;
194 struct list_head free_dma_desc;
195 struct list_head cb_desc;
196
197 /* ISR handler and tasklet for bottom half of isr handling */
198 dma_isr_handler isr_handler;
199 struct tasklet_struct tasklet;
200
201 /* Channel-slave specific configuration */
202 unsigned int slave_id;
203 struct dma_slave_config dma_sconfig;
204 struct tegra_dma_channel_regs channel_reg;
205
206 struct wait_queue_head wq;
207 };
208
209 /* tegra_dma: Tegra DMA specific information */
210 struct tegra_dma {
211 struct dma_device dma_dev;
212 struct device *dev;
213 struct clk *dma_clk;
214 struct reset_control *rst;
215 spinlock_t global_lock;
216 void __iomem *base_addr;
217 const struct tegra_dma_chip_data *chip_data;
218
219 /*
220 * Counter for managing global pausing of the DMA controller.
221 * Only applicable for devices that don't support individual
222 * channel pausing.
223 */
224 u32 global_pause_count;
225
226 /* Last member of the structure */
227 struct tegra_dma_channel channels[];
228 };
229
tdma_write(struct tegra_dma * tdma,u32 reg,u32 val)230 static inline void tdma_write(struct tegra_dma *tdma, u32 reg, u32 val)
231 {
232 writel(val, tdma->base_addr + reg);
233 }
234
tdc_write(struct tegra_dma_channel * tdc,u32 reg,u32 val)235 static inline void tdc_write(struct tegra_dma_channel *tdc,
236 u32 reg, u32 val)
237 {
238 writel(val, tdc->chan_addr + reg);
239 }
240
tdc_read(struct tegra_dma_channel * tdc,u32 reg)241 static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
242 {
243 return readl(tdc->chan_addr + reg);
244 }
245
to_tegra_dma_chan(struct dma_chan * dc)246 static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
247 {
248 return container_of(dc, struct tegra_dma_channel, dma_chan);
249 }
250
251 static inline struct tegra_dma_desc *
txd_to_tegra_dma_desc(struct dma_async_tx_descriptor * td)252 txd_to_tegra_dma_desc(struct dma_async_tx_descriptor *td)
253 {
254 return container_of(td, struct tegra_dma_desc, txd);
255 }
256
tdc2dev(struct tegra_dma_channel * tdc)257 static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
258 {
259 return &tdc->dma_chan.dev->device;
260 }
261
262 static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *tx);
263
264 /* Get DMA desc from free list, if not there then allocate it. */
tegra_dma_desc_get(struct tegra_dma_channel * tdc)265 static struct tegra_dma_desc *tegra_dma_desc_get(struct tegra_dma_channel *tdc)
266 {
267 struct tegra_dma_desc *dma_desc;
268 unsigned long flags;
269
270 spin_lock_irqsave(&tdc->lock, flags);
271
272 /* Do not allocate if desc are waiting for ack */
273 list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
274 if (async_tx_test_ack(&dma_desc->txd) && !dma_desc->cb_count) {
275 list_del(&dma_desc->node);
276 spin_unlock_irqrestore(&tdc->lock, flags);
277 dma_desc->txd.flags = 0;
278 return dma_desc;
279 }
280 }
281
282 spin_unlock_irqrestore(&tdc->lock, flags);
283
284 /* Allocate DMA desc */
285 dma_desc = kzalloc(sizeof(*dma_desc), GFP_NOWAIT);
286 if (!dma_desc)
287 return NULL;
288
289 dma_async_tx_descriptor_init(&dma_desc->txd, &tdc->dma_chan);
290 dma_desc->txd.tx_submit = tegra_dma_tx_submit;
291 dma_desc->txd.flags = 0;
292
293 return dma_desc;
294 }
295
tegra_dma_desc_put(struct tegra_dma_channel * tdc,struct tegra_dma_desc * dma_desc)296 static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
297 struct tegra_dma_desc *dma_desc)
298 {
299 unsigned long flags;
300
301 spin_lock_irqsave(&tdc->lock, flags);
302 if (!list_empty(&dma_desc->tx_list))
303 list_splice_init(&dma_desc->tx_list, &tdc->free_sg_req);
304 list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
305 spin_unlock_irqrestore(&tdc->lock, flags);
306 }
307
308 static struct tegra_dma_sg_req *
tegra_dma_sg_req_get(struct tegra_dma_channel * tdc)309 tegra_dma_sg_req_get(struct tegra_dma_channel *tdc)
310 {
311 struct tegra_dma_sg_req *sg_req;
312 unsigned long flags;
313
314 spin_lock_irqsave(&tdc->lock, flags);
315 if (!list_empty(&tdc->free_sg_req)) {
316 sg_req = list_first_entry(&tdc->free_sg_req, typeof(*sg_req),
317 node);
318 list_del(&sg_req->node);
319 spin_unlock_irqrestore(&tdc->lock, flags);
320 return sg_req;
321 }
322 spin_unlock_irqrestore(&tdc->lock, flags);
323
324 sg_req = kzalloc(sizeof(*sg_req), GFP_NOWAIT);
325
326 return sg_req;
327 }
328
tegra_dma_slave_config(struct dma_chan * dc,struct dma_slave_config * sconfig)329 static int tegra_dma_slave_config(struct dma_chan *dc,
330 struct dma_slave_config *sconfig)
331 {
332 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
333
334 if (!list_empty(&tdc->pending_sg_req)) {
335 dev_err(tdc2dev(tdc), "Configuration not allowed\n");
336 return -EBUSY;
337 }
338
339 memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
340 tdc->config_init = true;
341
342 return 0;
343 }
344
tegra_dma_global_pause(struct tegra_dma_channel * tdc,bool wait_for_burst_complete)345 static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
346 bool wait_for_burst_complete)
347 {
348 struct tegra_dma *tdma = tdc->tdma;
349
350 spin_lock(&tdma->global_lock);
351
352 if (tdc->tdma->global_pause_count == 0) {
353 tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
354 if (wait_for_burst_complete)
355 udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
356 }
357
358 tdc->tdma->global_pause_count++;
359
360 spin_unlock(&tdma->global_lock);
361 }
362
tegra_dma_global_resume(struct tegra_dma_channel * tdc)363 static void tegra_dma_global_resume(struct tegra_dma_channel *tdc)
364 {
365 struct tegra_dma *tdma = tdc->tdma;
366
367 spin_lock(&tdma->global_lock);
368
369 if (WARN_ON(tdc->tdma->global_pause_count == 0))
370 goto out;
371
372 if (--tdc->tdma->global_pause_count == 0)
373 tdma_write(tdma, TEGRA_APBDMA_GENERAL,
374 TEGRA_APBDMA_GENERAL_ENABLE);
375
376 out:
377 spin_unlock(&tdma->global_lock);
378 }
379
tegra_dma_pause(struct tegra_dma_channel * tdc,bool wait_for_burst_complete)380 static void tegra_dma_pause(struct tegra_dma_channel *tdc,
381 bool wait_for_burst_complete)
382 {
383 struct tegra_dma *tdma = tdc->tdma;
384
385 if (tdma->chip_data->support_channel_pause) {
386 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE,
387 TEGRA_APBDMA_CHAN_CSRE_PAUSE);
388 if (wait_for_burst_complete)
389 udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
390 } else {
391 tegra_dma_global_pause(tdc, wait_for_burst_complete);
392 }
393 }
394
tegra_dma_resume(struct tegra_dma_channel * tdc)395 static void tegra_dma_resume(struct tegra_dma_channel *tdc)
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, 0);
401 else
402 tegra_dma_global_resume(tdc);
403 }
404
tegra_dma_stop(struct tegra_dma_channel * tdc)405 static void tegra_dma_stop(struct tegra_dma_channel *tdc)
406 {
407 u32 csr, status;
408
409 /* Disable interrupts */
410 csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
411 csr &= ~TEGRA_APBDMA_CSR_IE_EOC;
412 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
413
414 /* Disable DMA */
415 csr &= ~TEGRA_APBDMA_CSR_ENB;
416 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
417
418 /* Clear interrupt status if it is there */
419 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
420 if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
421 dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
422 tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
423 }
424 tdc->busy = false;
425 }
426
tegra_dma_start(struct tegra_dma_channel * tdc,struct tegra_dma_sg_req * sg_req)427 static void tegra_dma_start(struct tegra_dma_channel *tdc,
428 struct tegra_dma_sg_req *sg_req)
429 {
430 struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
431
432 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, ch_regs->csr);
433 tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_regs->apb_seq);
434 tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_regs->apb_ptr);
435 tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_regs->ahb_seq);
436 tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_regs->ahb_ptr);
437 if (tdc->tdma->chip_data->support_separate_wcount_reg)
438 tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT, ch_regs->wcount);
439
440 /* Start DMA */
441 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
442 ch_regs->csr | TEGRA_APBDMA_CSR_ENB);
443 }
444
tegra_dma_configure_for_next(struct tegra_dma_channel * tdc,struct tegra_dma_sg_req * nsg_req)445 static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
446 struct tegra_dma_sg_req *nsg_req)
447 {
448 unsigned long status;
449
450 /*
451 * The DMA controller reloads the new configuration for next transfer
452 * after last burst of current transfer completes.
453 * If there is no IEC status then this makes sure that last burst
454 * has not be completed. There may be case that last burst is on
455 * flight and so it can complete but because DMA is paused, it
456 * will not generates interrupt as well as not reload the new
457 * configuration.
458 * If there is already IEC status then interrupt handler need to
459 * load new configuration.
460 */
461 tegra_dma_pause(tdc, false);
462 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
463
464 /*
465 * If interrupt is pending then do nothing as the ISR will handle
466 * the programing for new request.
467 */
468 if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
469 dev_err(tdc2dev(tdc),
470 "Skipping new configuration as interrupt is pending\n");
471 tegra_dma_resume(tdc);
472 return;
473 }
474
475 /* Safe to program new configuration */
476 tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, nsg_req->ch_regs.apb_ptr);
477 tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
478 if (tdc->tdma->chip_data->support_separate_wcount_reg)
479 tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
480 nsg_req->ch_regs.wcount);
481 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
482 nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
483 nsg_req->configured = true;
484 nsg_req->words_xferred = 0;
485
486 tegra_dma_resume(tdc);
487 }
488
tdc_start_head_req(struct tegra_dma_channel * tdc)489 static void tdc_start_head_req(struct tegra_dma_channel *tdc)
490 {
491 struct tegra_dma_sg_req *sg_req;
492
493 sg_req = list_first_entry(&tdc->pending_sg_req, typeof(*sg_req), node);
494 tegra_dma_start(tdc, sg_req);
495 sg_req->configured = true;
496 sg_req->words_xferred = 0;
497 tdc->busy = true;
498 }
499
tdc_configure_next_head_desc(struct tegra_dma_channel * tdc)500 static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
501 {
502 struct tegra_dma_sg_req *hsgreq, *hnsgreq;
503
504 hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
505 if (!list_is_last(&hsgreq->node, &tdc->pending_sg_req)) {
506 hnsgreq = list_first_entry(&hsgreq->node, typeof(*hnsgreq),
507 node);
508 tegra_dma_configure_for_next(tdc, hnsgreq);
509 }
510 }
511
512 static inline unsigned int
get_current_xferred_count(struct tegra_dma_channel * tdc,struct tegra_dma_sg_req * sg_req,unsigned long status)513 get_current_xferred_count(struct tegra_dma_channel *tdc,
514 struct tegra_dma_sg_req *sg_req,
515 unsigned long status)
516 {
517 return sg_req->req_len - (status & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
518 }
519
tegra_dma_abort_all(struct tegra_dma_channel * tdc)520 static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
521 {
522 struct tegra_dma_desc *dma_desc;
523 struct tegra_dma_sg_req *sgreq;
524
525 while (!list_empty(&tdc->pending_sg_req)) {
526 sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq),
527 node);
528 list_move_tail(&sgreq->node, &tdc->free_sg_req);
529 if (sgreq->last_sg) {
530 dma_desc = sgreq->dma_desc;
531 dma_desc->dma_status = DMA_ERROR;
532 list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
533
534 /* Add in cb list if it is not there. */
535 if (!dma_desc->cb_count)
536 list_add_tail(&dma_desc->cb_node,
537 &tdc->cb_desc);
538 dma_desc->cb_count++;
539 }
540 }
541 tdc->isr_handler = NULL;
542 }
543
handle_continuous_head_request(struct tegra_dma_channel * tdc,bool to_terminate)544 static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
545 bool to_terminate)
546 {
547 struct tegra_dma_sg_req *hsgreq;
548
549 /*
550 * Check that head req on list should be in flight.
551 * If it is not in flight then abort transfer as
552 * looping of transfer can not continue.
553 */
554 hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
555 if (!hsgreq->configured) {
556 tegra_dma_stop(tdc);
557 pm_runtime_put(tdc->tdma->dev);
558 dev_err(tdc2dev(tdc), "DMA transfer underflow, aborting DMA\n");
559 tegra_dma_abort_all(tdc);
560 return false;
561 }
562
563 /* Configure next request */
564 if (!to_terminate)
565 tdc_configure_next_head_desc(tdc);
566
567 return true;
568 }
569
handle_once_dma_done(struct tegra_dma_channel * tdc,bool to_terminate)570 static void handle_once_dma_done(struct tegra_dma_channel *tdc,
571 bool to_terminate)
572 {
573 struct tegra_dma_desc *dma_desc;
574 struct tegra_dma_sg_req *sgreq;
575
576 tdc->busy = false;
577 sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
578 dma_desc = sgreq->dma_desc;
579 dma_desc->bytes_transferred += sgreq->req_len;
580
581 list_del(&sgreq->node);
582 if (sgreq->last_sg) {
583 dma_desc->dma_status = DMA_COMPLETE;
584 dma_cookie_complete(&dma_desc->txd);
585 if (!dma_desc->cb_count)
586 list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
587 dma_desc->cb_count++;
588 list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
589 }
590 list_add_tail(&sgreq->node, &tdc->free_sg_req);
591
592 /* Do not start DMA if it is going to be terminate */
593 if (to_terminate)
594 return;
595
596 if (list_empty(&tdc->pending_sg_req)) {
597 pm_runtime_put(tdc->tdma->dev);
598 return;
599 }
600
601 tdc_start_head_req(tdc);
602 }
603
handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel * tdc,bool to_terminate)604 static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
605 bool to_terminate)
606 {
607 struct tegra_dma_desc *dma_desc;
608 struct tegra_dma_sg_req *sgreq;
609 bool st;
610
611 sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
612 dma_desc = sgreq->dma_desc;
613 /* if we dma for long enough the transfer count will wrap */
614 dma_desc->bytes_transferred =
615 (dma_desc->bytes_transferred + sgreq->req_len) %
616 dma_desc->bytes_requested;
617
618 /* Callback need to be call */
619 if (!dma_desc->cb_count)
620 list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
621 dma_desc->cb_count++;
622
623 sgreq->words_xferred = 0;
624
625 /* If not last req then put at end of pending list */
626 if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
627 list_move_tail(&sgreq->node, &tdc->pending_sg_req);
628 sgreq->configured = false;
629 st = handle_continuous_head_request(tdc, to_terminate);
630 if (!st)
631 dma_desc->dma_status = DMA_ERROR;
632 }
633 }
634
tegra_dma_tasklet(struct tasklet_struct * t)635 static void tegra_dma_tasklet(struct tasklet_struct *t)
636 {
637 struct tegra_dma_channel *tdc = from_tasklet(tdc, t, tasklet);
638 struct dmaengine_desc_callback cb;
639 struct tegra_dma_desc *dma_desc;
640 unsigned int cb_count;
641 unsigned long flags;
642
643 spin_lock_irqsave(&tdc->lock, flags);
644 while (!list_empty(&tdc->cb_desc)) {
645 dma_desc = list_first_entry(&tdc->cb_desc, typeof(*dma_desc),
646 cb_node);
647 list_del(&dma_desc->cb_node);
648 dmaengine_desc_get_callback(&dma_desc->txd, &cb);
649 cb_count = dma_desc->cb_count;
650 dma_desc->cb_count = 0;
651 trace_tegra_dma_complete_cb(&tdc->dma_chan, cb_count,
652 cb.callback);
653 spin_unlock_irqrestore(&tdc->lock, flags);
654 while (cb_count--)
655 dmaengine_desc_callback_invoke(&cb, NULL);
656 spin_lock_irqsave(&tdc->lock, flags);
657 }
658 spin_unlock_irqrestore(&tdc->lock, flags);
659 }
660
tegra_dma_isr(int irq,void * dev_id)661 static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
662 {
663 struct tegra_dma_channel *tdc = dev_id;
664 u32 status;
665
666 spin_lock(&tdc->lock);
667
668 trace_tegra_dma_isr(&tdc->dma_chan, irq);
669 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
670 if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
671 tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
672 tdc->isr_handler(tdc, false);
673 tasklet_schedule(&tdc->tasklet);
674 wake_up_all(&tdc->wq);
675 spin_unlock(&tdc->lock);
676 return IRQ_HANDLED;
677 }
678
679 spin_unlock(&tdc->lock);
680 dev_info(tdc2dev(tdc), "Interrupt already served status 0x%08x\n",
681 status);
682
683 return IRQ_NONE;
684 }
685
tegra_dma_tx_submit(struct dma_async_tx_descriptor * txd)686 static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *txd)
687 {
688 struct tegra_dma_desc *dma_desc = txd_to_tegra_dma_desc(txd);
689 struct tegra_dma_channel *tdc = to_tegra_dma_chan(txd->chan);
690 unsigned long flags;
691 dma_cookie_t cookie;
692
693 spin_lock_irqsave(&tdc->lock, flags);
694 dma_desc->dma_status = DMA_IN_PROGRESS;
695 cookie = dma_cookie_assign(&dma_desc->txd);
696 list_splice_tail_init(&dma_desc->tx_list, &tdc->pending_sg_req);
697 spin_unlock_irqrestore(&tdc->lock, flags);
698
699 return cookie;
700 }
701
tegra_dma_issue_pending(struct dma_chan * dc)702 static void tegra_dma_issue_pending(struct dma_chan *dc)
703 {
704 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
705 unsigned long flags;
706 int err;
707
708 spin_lock_irqsave(&tdc->lock, flags);
709 if (list_empty(&tdc->pending_sg_req)) {
710 dev_err(tdc2dev(tdc), "No DMA request\n");
711 goto end;
712 }
713 if (!tdc->busy) {
714 err = pm_runtime_resume_and_get(tdc->tdma->dev);
715 if (err < 0) {
716 dev_err(tdc2dev(tdc), "Failed to enable DMA\n");
717 goto end;
718 }
719
720 tdc_start_head_req(tdc);
721
722 /* Continuous single mode: Configure next req */
723 if (tdc->cyclic) {
724 /*
725 * Wait for 1 burst time for configure DMA for
726 * next transfer.
727 */
728 udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
729 tdc_configure_next_head_desc(tdc);
730 }
731 }
732 end:
733 spin_unlock_irqrestore(&tdc->lock, flags);
734 }
735
tegra_dma_terminate_all(struct dma_chan * dc)736 static int tegra_dma_terminate_all(struct dma_chan *dc)
737 {
738 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
739 struct tegra_dma_desc *dma_desc;
740 struct tegra_dma_sg_req *sgreq;
741 unsigned long flags;
742 u32 status, wcount;
743 bool was_busy;
744
745 spin_lock_irqsave(&tdc->lock, flags);
746
747 if (!tdc->busy)
748 goto skip_dma_stop;
749
750 /* Pause DMA before checking the queue status */
751 tegra_dma_pause(tdc, true);
752
753 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
754 if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
755 dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
756 tdc->isr_handler(tdc, true);
757 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
758 }
759 if (tdc->tdma->chip_data->support_separate_wcount_reg)
760 wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
761 else
762 wcount = status;
763
764 was_busy = tdc->busy;
765 tegra_dma_stop(tdc);
766
767 if (!list_empty(&tdc->pending_sg_req) && was_busy) {
768 sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq),
769 node);
770 sgreq->dma_desc->bytes_transferred +=
771 get_current_xferred_count(tdc, sgreq, wcount);
772 }
773 tegra_dma_resume(tdc);
774
775 pm_runtime_put(tdc->tdma->dev);
776 wake_up_all(&tdc->wq);
777
778 skip_dma_stop:
779 tegra_dma_abort_all(tdc);
780
781 while (!list_empty(&tdc->cb_desc)) {
782 dma_desc = list_first_entry(&tdc->cb_desc, typeof(*dma_desc),
783 cb_node);
784 list_del(&dma_desc->cb_node);
785 dma_desc->cb_count = 0;
786 }
787 spin_unlock_irqrestore(&tdc->lock, flags);
788
789 return 0;
790 }
791
tegra_dma_eoc_interrupt_deasserted(struct tegra_dma_channel * tdc)792 static bool tegra_dma_eoc_interrupt_deasserted(struct tegra_dma_channel *tdc)
793 {
794 unsigned long flags;
795 u32 status;
796
797 spin_lock_irqsave(&tdc->lock, flags);
798 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
799 spin_unlock_irqrestore(&tdc->lock, flags);
800
801 return !(status & TEGRA_APBDMA_STATUS_ISE_EOC);
802 }
803
tegra_dma_synchronize(struct dma_chan * dc)804 static void tegra_dma_synchronize(struct dma_chan *dc)
805 {
806 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
807 int err;
808
809 err = pm_runtime_resume_and_get(tdc->tdma->dev);
810 if (err < 0) {
811 dev_err(tdc2dev(tdc), "Failed to synchronize DMA: %d\n", err);
812 return;
813 }
814
815 /*
816 * CPU, which handles interrupt, could be busy in
817 * uninterruptible state, in this case sibling CPU
818 * should wait until interrupt is handled.
819 */
820 wait_event(tdc->wq, tegra_dma_eoc_interrupt_deasserted(tdc));
821
822 tasklet_kill(&tdc->tasklet);
823
824 pm_runtime_put(tdc->tdma->dev);
825 }
826
tegra_dma_sg_bytes_xferred(struct tegra_dma_channel * tdc,struct tegra_dma_sg_req * sg_req)827 static unsigned int tegra_dma_sg_bytes_xferred(struct tegra_dma_channel *tdc,
828 struct tegra_dma_sg_req *sg_req)
829 {
830 u32 status, wcount = 0;
831
832 if (!list_is_first(&sg_req->node, &tdc->pending_sg_req))
833 return 0;
834
835 if (tdc->tdma->chip_data->support_separate_wcount_reg)
836 wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
837
838 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
839
840 if (!tdc->tdma->chip_data->support_separate_wcount_reg)
841 wcount = status;
842
843 if (status & TEGRA_APBDMA_STATUS_ISE_EOC)
844 return sg_req->req_len;
845
846 wcount = get_current_xferred_count(tdc, sg_req, wcount);
847
848 if (!wcount) {
849 /*
850 * If wcount wasn't ever polled for this SG before, then
851 * simply assume that transfer hasn't started yet.
852 *
853 * Otherwise it's the end of the transfer.
854 *
855 * The alternative would be to poll the status register
856 * until EOC bit is set or wcount goes UP. That's so
857 * because EOC bit is getting set only after the last
858 * burst's completion and counter is less than the actual
859 * transfer size by 4 bytes. The counter value wraps around
860 * in a cyclic mode before EOC is set(!), so we can't easily
861 * distinguish start of transfer from its end.
862 */
863 if (sg_req->words_xferred)
864 wcount = sg_req->req_len - 4;
865
866 } else if (wcount < sg_req->words_xferred) {
867 /*
868 * This case will never happen for a non-cyclic transfer.
869 *
870 * For a cyclic transfer, although it is possible for the
871 * next transfer to have already started (resetting the word
872 * count), this case should still not happen because we should
873 * have detected that the EOC bit is set and hence the transfer
874 * was completed.
875 */
876 WARN_ON_ONCE(1);
877
878 wcount = sg_req->req_len - 4;
879 } else {
880 sg_req->words_xferred = wcount;
881 }
882
883 return wcount;
884 }
885
tegra_dma_tx_status(struct dma_chan * dc,dma_cookie_t cookie,struct dma_tx_state * txstate)886 static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
887 dma_cookie_t cookie,
888 struct dma_tx_state *txstate)
889 {
890 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
891 struct tegra_dma_desc *dma_desc;
892 struct tegra_dma_sg_req *sg_req;
893 enum dma_status ret;
894 unsigned long flags;
895 unsigned int residual;
896 unsigned int bytes = 0;
897
898 ret = dma_cookie_status(dc, cookie, txstate);
899 if (ret == DMA_COMPLETE)
900 return ret;
901
902 spin_lock_irqsave(&tdc->lock, flags);
903
904 /* Check on wait_ack desc status */
905 list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
906 if (dma_desc->txd.cookie == cookie) {
907 ret = dma_desc->dma_status;
908 goto found;
909 }
910 }
911
912 /* Check in pending list */
913 list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
914 dma_desc = sg_req->dma_desc;
915 if (dma_desc->txd.cookie == cookie) {
916 bytes = tegra_dma_sg_bytes_xferred(tdc, sg_req);
917 ret = dma_desc->dma_status;
918 goto found;
919 }
920 }
921
922 dev_dbg(tdc2dev(tdc), "cookie %d not found\n", cookie);
923 dma_desc = NULL;
924
925 found:
926 if (dma_desc && txstate) {
927 residual = dma_desc->bytes_requested -
928 ((dma_desc->bytes_transferred + bytes) %
929 dma_desc->bytes_requested);
930 dma_set_residue(txstate, residual);
931 }
932
933 trace_tegra_dma_tx_status(&tdc->dma_chan, cookie, txstate);
934 spin_unlock_irqrestore(&tdc->lock, flags);
935
936 return ret;
937 }
938
get_bus_width(struct tegra_dma_channel * tdc,enum dma_slave_buswidth slave_bw)939 static inline unsigned int get_bus_width(struct tegra_dma_channel *tdc,
940 enum dma_slave_buswidth slave_bw)
941 {
942 switch (slave_bw) {
943 case DMA_SLAVE_BUSWIDTH_1_BYTE:
944 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8;
945 case DMA_SLAVE_BUSWIDTH_2_BYTES:
946 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16;
947 case DMA_SLAVE_BUSWIDTH_4_BYTES:
948 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
949 case DMA_SLAVE_BUSWIDTH_8_BYTES:
950 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64;
951 default:
952 dev_warn(tdc2dev(tdc),
953 "slave bw is not supported, using 32bits\n");
954 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
955 }
956 }
957
get_burst_size(struct tegra_dma_channel * tdc,u32 burst_size,enum dma_slave_buswidth slave_bw,u32 len)958 static inline unsigned int get_burst_size(struct tegra_dma_channel *tdc,
959 u32 burst_size,
960 enum dma_slave_buswidth slave_bw,
961 u32 len)
962 {
963 unsigned int burst_byte, burst_ahb_width;
964
965 /*
966 * burst_size from client is in terms of the bus_width.
967 * convert them into AHB memory width which is 4 byte.
968 */
969 burst_byte = burst_size * slave_bw;
970 burst_ahb_width = burst_byte / 4;
971
972 /* If burst size is 0 then calculate the burst size based on length */
973 if (!burst_ahb_width) {
974 if (len & 0xF)
975 return TEGRA_APBDMA_AHBSEQ_BURST_1;
976 else if ((len >> 4) & 0x1)
977 return TEGRA_APBDMA_AHBSEQ_BURST_4;
978 else
979 return TEGRA_APBDMA_AHBSEQ_BURST_8;
980 }
981 if (burst_ahb_width < 4)
982 return TEGRA_APBDMA_AHBSEQ_BURST_1;
983 else if (burst_ahb_width < 8)
984 return TEGRA_APBDMA_AHBSEQ_BURST_4;
985 else
986 return TEGRA_APBDMA_AHBSEQ_BURST_8;
987 }
988
get_transfer_param(struct tegra_dma_channel * tdc,enum dma_transfer_direction direction,u32 * apb_addr,u32 * apb_seq,u32 * csr,unsigned int * burst_size,enum dma_slave_buswidth * slave_bw)989 static int get_transfer_param(struct tegra_dma_channel *tdc,
990 enum dma_transfer_direction direction,
991 u32 *apb_addr,
992 u32 *apb_seq,
993 u32 *csr,
994 unsigned int *burst_size,
995 enum dma_slave_buswidth *slave_bw)
996 {
997 switch (direction) {
998 case DMA_MEM_TO_DEV:
999 *apb_addr = tdc->dma_sconfig.dst_addr;
1000 *apb_seq = get_bus_width(tdc, tdc->dma_sconfig.dst_addr_width);
1001 *burst_size = tdc->dma_sconfig.dst_maxburst;
1002 *slave_bw = tdc->dma_sconfig.dst_addr_width;
1003 *csr = TEGRA_APBDMA_CSR_DIR;
1004 return 0;
1005
1006 case DMA_DEV_TO_MEM:
1007 *apb_addr = tdc->dma_sconfig.src_addr;
1008 *apb_seq = get_bus_width(tdc, tdc->dma_sconfig.src_addr_width);
1009 *burst_size = tdc->dma_sconfig.src_maxburst;
1010 *slave_bw = tdc->dma_sconfig.src_addr_width;
1011 *csr = 0;
1012 return 0;
1013
1014 default:
1015 dev_err(tdc2dev(tdc), "DMA direction is not supported\n");
1016 break;
1017 }
1018
1019 return -EINVAL;
1020 }
1021
tegra_dma_prep_wcount(struct tegra_dma_channel * tdc,struct tegra_dma_channel_regs * ch_regs,u32 len)1022 static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
1023 struct tegra_dma_channel_regs *ch_regs,
1024 u32 len)
1025 {
1026 u32 len_field = (len - 4) & 0xFFFC;
1027
1028 if (tdc->tdma->chip_data->support_separate_wcount_reg)
1029 ch_regs->wcount = len_field;
1030 else
1031 ch_regs->csr |= len_field;
1032 }
1033
1034 static struct dma_async_tx_descriptor *
tegra_dma_prep_slave_sg(struct dma_chan * dc,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction direction,unsigned long flags,void * context)1035 tegra_dma_prep_slave_sg(struct dma_chan *dc,
1036 struct scatterlist *sgl,
1037 unsigned int sg_len,
1038 enum dma_transfer_direction direction,
1039 unsigned long flags,
1040 void *context)
1041 {
1042 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1043 struct tegra_dma_sg_req *sg_req = NULL;
1044 u32 csr, ahb_seq, apb_ptr, apb_seq;
1045 enum dma_slave_buswidth slave_bw;
1046 struct tegra_dma_desc *dma_desc;
1047 struct list_head req_list;
1048 struct scatterlist *sg;
1049 unsigned int burst_size;
1050 unsigned int i;
1051
1052 if (!tdc->config_init) {
1053 dev_err(tdc2dev(tdc), "DMA channel is not configured\n");
1054 return NULL;
1055 }
1056 if (sg_len < 1) {
1057 dev_err(tdc2dev(tdc), "Invalid segment length %d\n", sg_len);
1058 return NULL;
1059 }
1060
1061 if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
1062 &burst_size, &slave_bw) < 0)
1063 return NULL;
1064
1065 INIT_LIST_HEAD(&req_list);
1066
1067 ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
1068 ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
1069 TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
1070 ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
1071
1072 csr |= TEGRA_APBDMA_CSR_ONCE;
1073
1074 if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) {
1075 csr |= TEGRA_APBDMA_CSR_FLOW;
1076 csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
1077 }
1078
1079 if (flags & DMA_PREP_INTERRUPT) {
1080 csr |= TEGRA_APBDMA_CSR_IE_EOC;
1081 } else {
1082 WARN_ON_ONCE(1);
1083 return NULL;
1084 }
1085
1086 apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
1087
1088 dma_desc = tegra_dma_desc_get(tdc);
1089 if (!dma_desc) {
1090 dev_err(tdc2dev(tdc), "DMA descriptors not available\n");
1091 return NULL;
1092 }
1093 INIT_LIST_HEAD(&dma_desc->tx_list);
1094 INIT_LIST_HEAD(&dma_desc->cb_node);
1095 dma_desc->cb_count = 0;
1096 dma_desc->bytes_requested = 0;
1097 dma_desc->bytes_transferred = 0;
1098 dma_desc->dma_status = DMA_IN_PROGRESS;
1099
1100 /* Make transfer requests */
1101 for_each_sg(sgl, sg, sg_len, i) {
1102 u32 len, mem;
1103
1104 mem = sg_dma_address(sg);
1105 len = sg_dma_len(sg);
1106
1107 if ((len & 3) || (mem & 3) ||
1108 len > tdc->tdma->chip_data->max_dma_count) {
1109 dev_err(tdc2dev(tdc),
1110 "DMA length/memory address is not supported\n");
1111 tegra_dma_desc_put(tdc, dma_desc);
1112 return NULL;
1113 }
1114
1115 sg_req = tegra_dma_sg_req_get(tdc);
1116 if (!sg_req) {
1117 dev_err(tdc2dev(tdc), "DMA sg-req not available\n");
1118 tegra_dma_desc_put(tdc, dma_desc);
1119 return NULL;
1120 }
1121
1122 ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1123 dma_desc->bytes_requested += len;
1124
1125 sg_req->ch_regs.apb_ptr = apb_ptr;
1126 sg_req->ch_regs.ahb_ptr = mem;
1127 sg_req->ch_regs.csr = csr;
1128 tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1129 sg_req->ch_regs.apb_seq = apb_seq;
1130 sg_req->ch_regs.ahb_seq = ahb_seq;
1131 sg_req->configured = false;
1132 sg_req->last_sg = false;
1133 sg_req->dma_desc = dma_desc;
1134 sg_req->req_len = len;
1135
1136 list_add_tail(&sg_req->node, &dma_desc->tx_list);
1137 }
1138 sg_req->last_sg = true;
1139 if (flags & DMA_CTRL_ACK)
1140 dma_desc->txd.flags = DMA_CTRL_ACK;
1141
1142 /*
1143 * Make sure that mode should not be conflicting with currently
1144 * configured mode.
1145 */
1146 if (!tdc->isr_handler) {
1147 tdc->isr_handler = handle_once_dma_done;
1148 tdc->cyclic = false;
1149 } else {
1150 if (tdc->cyclic) {
1151 dev_err(tdc2dev(tdc), "DMA configured in cyclic mode\n");
1152 tegra_dma_desc_put(tdc, dma_desc);
1153 return NULL;
1154 }
1155 }
1156
1157 return &dma_desc->txd;
1158 }
1159
1160 static struct dma_async_tx_descriptor *
tegra_dma_prep_dma_cyclic(struct dma_chan * dc,dma_addr_t buf_addr,size_t buf_len,size_t period_len,enum dma_transfer_direction direction,unsigned long flags)1161 tegra_dma_prep_dma_cyclic(struct dma_chan *dc, dma_addr_t buf_addr,
1162 size_t buf_len,
1163 size_t period_len,
1164 enum dma_transfer_direction direction,
1165 unsigned long flags)
1166 {
1167 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1168 struct tegra_dma_sg_req *sg_req = NULL;
1169 u32 csr, ahb_seq, apb_ptr, apb_seq;
1170 enum dma_slave_buswidth slave_bw;
1171 struct tegra_dma_desc *dma_desc;
1172 dma_addr_t mem = buf_addr;
1173 unsigned int burst_size;
1174 size_t len, remain_len;
1175
1176 if (!buf_len || !period_len) {
1177 dev_err(tdc2dev(tdc), "Invalid buffer/period len\n");
1178 return NULL;
1179 }
1180
1181 if (!tdc->config_init) {
1182 dev_err(tdc2dev(tdc), "DMA slave is not configured\n");
1183 return NULL;
1184 }
1185
1186 /*
1187 * We allow to take more number of requests till DMA is
1188 * not started. The driver will loop over all requests.
1189 * Once DMA is started then new requests can be queued only after
1190 * terminating the DMA.
1191 */
1192 if (tdc->busy) {
1193 dev_err(tdc2dev(tdc), "Request not allowed when DMA running\n");
1194 return NULL;
1195 }
1196
1197 /*
1198 * We only support cycle transfer when buf_len is multiple of
1199 * period_len.
1200 */
1201 if (buf_len % period_len) {
1202 dev_err(tdc2dev(tdc), "buf_len is not multiple of period_len\n");
1203 return NULL;
1204 }
1205
1206 len = period_len;
1207 if ((len & 3) || (buf_addr & 3) ||
1208 len > tdc->tdma->chip_data->max_dma_count) {
1209 dev_err(tdc2dev(tdc), "Req len/mem address is not correct\n");
1210 return NULL;
1211 }
1212
1213 if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
1214 &burst_size, &slave_bw) < 0)
1215 return NULL;
1216
1217 ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
1218 ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
1219 TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
1220 ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
1221
1222 if (tdc->slave_id != TEGRA_APBDMA_SLAVE_ID_INVALID) {
1223 csr |= TEGRA_APBDMA_CSR_FLOW;
1224 csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
1225 }
1226
1227 if (flags & DMA_PREP_INTERRUPT) {
1228 csr |= TEGRA_APBDMA_CSR_IE_EOC;
1229 } else {
1230 WARN_ON_ONCE(1);
1231 return NULL;
1232 }
1233
1234 apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
1235
1236 dma_desc = tegra_dma_desc_get(tdc);
1237 if (!dma_desc) {
1238 dev_err(tdc2dev(tdc), "not enough descriptors available\n");
1239 return NULL;
1240 }
1241
1242 INIT_LIST_HEAD(&dma_desc->tx_list);
1243 INIT_LIST_HEAD(&dma_desc->cb_node);
1244 dma_desc->cb_count = 0;
1245
1246 dma_desc->bytes_transferred = 0;
1247 dma_desc->bytes_requested = buf_len;
1248 remain_len = buf_len;
1249
1250 /* Split transfer equal to period size */
1251 while (remain_len) {
1252 sg_req = tegra_dma_sg_req_get(tdc);
1253 if (!sg_req) {
1254 dev_err(tdc2dev(tdc), "DMA sg-req not available\n");
1255 tegra_dma_desc_put(tdc, dma_desc);
1256 return NULL;
1257 }
1258
1259 ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1260 sg_req->ch_regs.apb_ptr = apb_ptr;
1261 sg_req->ch_regs.ahb_ptr = mem;
1262 sg_req->ch_regs.csr = csr;
1263 tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1264 sg_req->ch_regs.apb_seq = apb_seq;
1265 sg_req->ch_regs.ahb_seq = ahb_seq;
1266 sg_req->configured = false;
1267 sg_req->last_sg = false;
1268 sg_req->dma_desc = dma_desc;
1269 sg_req->req_len = len;
1270
1271 list_add_tail(&sg_req->node, &dma_desc->tx_list);
1272 remain_len -= len;
1273 mem += len;
1274 }
1275 sg_req->last_sg = true;
1276 if (flags & DMA_CTRL_ACK)
1277 dma_desc->txd.flags = DMA_CTRL_ACK;
1278
1279 /*
1280 * Make sure that mode should not be conflicting with currently
1281 * configured mode.
1282 */
1283 if (!tdc->isr_handler) {
1284 tdc->isr_handler = handle_cont_sngl_cycle_dma_done;
1285 tdc->cyclic = true;
1286 } else {
1287 if (!tdc->cyclic) {
1288 dev_err(tdc2dev(tdc), "DMA configuration conflict\n");
1289 tegra_dma_desc_put(tdc, dma_desc);
1290 return NULL;
1291 }
1292 }
1293
1294 return &dma_desc->txd;
1295 }
1296
tegra_dma_alloc_chan_resources(struct dma_chan * dc)1297 static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
1298 {
1299 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1300
1301 dma_cookie_init(&tdc->dma_chan);
1302
1303 return 0;
1304 }
1305
tegra_dma_free_chan_resources(struct dma_chan * dc)1306 static void tegra_dma_free_chan_resources(struct dma_chan *dc)
1307 {
1308 struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1309 struct tegra_dma_desc *dma_desc;
1310 struct tegra_dma_sg_req *sg_req;
1311 struct list_head dma_desc_list;
1312 struct list_head sg_req_list;
1313
1314 INIT_LIST_HEAD(&dma_desc_list);
1315 INIT_LIST_HEAD(&sg_req_list);
1316
1317 dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
1318
1319 tegra_dma_terminate_all(dc);
1320 tasklet_kill(&tdc->tasklet);
1321
1322 list_splice_init(&tdc->pending_sg_req, &sg_req_list);
1323 list_splice_init(&tdc->free_sg_req, &sg_req_list);
1324 list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
1325 INIT_LIST_HEAD(&tdc->cb_desc);
1326 tdc->config_init = false;
1327 tdc->isr_handler = NULL;
1328
1329 while (!list_empty(&dma_desc_list)) {
1330 dma_desc = list_first_entry(&dma_desc_list, typeof(*dma_desc),
1331 node);
1332 list_del(&dma_desc->node);
1333 kfree(dma_desc);
1334 }
1335
1336 while (!list_empty(&sg_req_list)) {
1337 sg_req = list_first_entry(&sg_req_list, typeof(*sg_req), node);
1338 list_del(&sg_req->node);
1339 kfree(sg_req);
1340 }
1341
1342 tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1343 }
1344
tegra_dma_of_xlate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)1345 static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
1346 struct of_dma *ofdma)
1347 {
1348 struct tegra_dma *tdma = ofdma->of_dma_data;
1349 struct tegra_dma_channel *tdc;
1350 struct dma_chan *chan;
1351
1352 if (dma_spec->args[0] > TEGRA_APBDMA_CSR_REQ_SEL_MASK) {
1353 dev_err(tdma->dev, "Invalid slave id: %d\n", dma_spec->args[0]);
1354 return NULL;
1355 }
1356
1357 chan = dma_get_any_slave_channel(&tdma->dma_dev);
1358 if (!chan)
1359 return NULL;
1360
1361 tdc = to_tegra_dma_chan(chan);
1362 tdc->slave_id = dma_spec->args[0];
1363
1364 return chan;
1365 }
1366
1367 /* Tegra20 specific DMA controller information */
1368 static const struct tegra_dma_chip_data tegra20_dma_chip_data = {
1369 .nr_channels = 16,
1370 .channel_reg_size = 0x20,
1371 .max_dma_count = 1024UL * 64,
1372 .support_channel_pause = false,
1373 .support_separate_wcount_reg = false,
1374 };
1375
1376 /* Tegra30 specific DMA controller information */
1377 static const struct tegra_dma_chip_data tegra30_dma_chip_data = {
1378 .nr_channels = 32,
1379 .channel_reg_size = 0x20,
1380 .max_dma_count = 1024UL * 64,
1381 .support_channel_pause = false,
1382 .support_separate_wcount_reg = false,
1383 };
1384
1385 /* Tegra114 specific DMA controller information */
1386 static const struct tegra_dma_chip_data tegra114_dma_chip_data = {
1387 .nr_channels = 32,
1388 .channel_reg_size = 0x20,
1389 .max_dma_count = 1024UL * 64,
1390 .support_channel_pause = true,
1391 .support_separate_wcount_reg = false,
1392 };
1393
1394 /* Tegra148 specific DMA controller information */
1395 static const struct tegra_dma_chip_data tegra148_dma_chip_data = {
1396 .nr_channels = 32,
1397 .channel_reg_size = 0x40,
1398 .max_dma_count = 1024UL * 64,
1399 .support_channel_pause = true,
1400 .support_separate_wcount_reg = true,
1401 };
1402
tegra_dma_init_hw(struct tegra_dma * tdma)1403 static int tegra_dma_init_hw(struct tegra_dma *tdma)
1404 {
1405 int err;
1406
1407 err = reset_control_assert(tdma->rst);
1408 if (err) {
1409 dev_err(tdma->dev, "failed to assert reset: %d\n", err);
1410 return err;
1411 }
1412
1413 err = clk_enable(tdma->dma_clk);
1414 if (err) {
1415 dev_err(tdma->dev, "failed to enable clk: %d\n", err);
1416 return err;
1417 }
1418
1419 /* reset DMA controller */
1420 udelay(2);
1421 reset_control_deassert(tdma->rst);
1422
1423 /* enable global DMA registers */
1424 tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
1425 tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1426 tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFF);
1427
1428 clk_disable(tdma->dma_clk);
1429
1430 return 0;
1431 }
1432
tegra_dma_probe(struct platform_device * pdev)1433 static int tegra_dma_probe(struct platform_device *pdev)
1434 {
1435 const struct tegra_dma_chip_data *cdata;
1436 struct tegra_dma *tdma;
1437 unsigned int i;
1438 size_t size;
1439 int ret;
1440
1441 cdata = of_device_get_match_data(&pdev->dev);
1442 size = struct_size(tdma, channels, cdata->nr_channels);
1443
1444 tdma = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
1445 if (!tdma)
1446 return -ENOMEM;
1447
1448 tdma->dev = &pdev->dev;
1449 tdma->chip_data = cdata;
1450 platform_set_drvdata(pdev, tdma);
1451
1452 tdma->base_addr = devm_platform_ioremap_resource(pdev, 0);
1453 if (IS_ERR(tdma->base_addr))
1454 return PTR_ERR(tdma->base_addr);
1455
1456 tdma->dma_clk = devm_clk_get(&pdev->dev, NULL);
1457 if (IS_ERR(tdma->dma_clk)) {
1458 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1459 return PTR_ERR(tdma->dma_clk);
1460 }
1461
1462 tdma->rst = devm_reset_control_get(&pdev->dev, "dma");
1463 if (IS_ERR(tdma->rst)) {
1464 dev_err(&pdev->dev, "Error: Missing reset\n");
1465 return PTR_ERR(tdma->rst);
1466 }
1467
1468 spin_lock_init(&tdma->global_lock);
1469
1470 ret = clk_prepare(tdma->dma_clk);
1471 if (ret)
1472 return ret;
1473
1474 ret = tegra_dma_init_hw(tdma);
1475 if (ret)
1476 goto err_clk_unprepare;
1477
1478 pm_runtime_irq_safe(&pdev->dev);
1479 pm_runtime_enable(&pdev->dev);
1480
1481 INIT_LIST_HEAD(&tdma->dma_dev.channels);
1482 for (i = 0; i < cdata->nr_channels; i++) {
1483 struct tegra_dma_channel *tdc = &tdma->channels[i];
1484 int irq;
1485
1486 tdc->chan_addr = tdma->base_addr +
1487 TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET +
1488 (i * cdata->channel_reg_size);
1489
1490 irq = platform_get_irq(pdev, i);
1491 if (irq < 0) {
1492 ret = irq;
1493 goto err_pm_disable;
1494 }
1495
1496 snprintf(tdc->name, sizeof(tdc->name), "apbdma.%d", i);
1497 ret = devm_request_irq(&pdev->dev, irq, tegra_dma_isr, 0,
1498 tdc->name, tdc);
1499 if (ret) {
1500 dev_err(&pdev->dev,
1501 "request_irq failed with err %d channel %d\n",
1502 ret, i);
1503 goto err_pm_disable;
1504 }
1505
1506 tdc->dma_chan.device = &tdma->dma_dev;
1507 dma_cookie_init(&tdc->dma_chan);
1508 list_add_tail(&tdc->dma_chan.device_node,
1509 &tdma->dma_dev.channels);
1510 tdc->tdma = tdma;
1511 tdc->id = i;
1512 tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1513
1514 tasklet_setup(&tdc->tasklet, tegra_dma_tasklet);
1515 spin_lock_init(&tdc->lock);
1516 init_waitqueue_head(&tdc->wq);
1517
1518 INIT_LIST_HEAD(&tdc->pending_sg_req);
1519 INIT_LIST_HEAD(&tdc->free_sg_req);
1520 INIT_LIST_HEAD(&tdc->free_dma_desc);
1521 INIT_LIST_HEAD(&tdc->cb_desc);
1522 }
1523
1524 dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
1525 dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
1526 dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
1527
1528 tdma->global_pause_count = 0;
1529 tdma->dma_dev.dev = &pdev->dev;
1530 tdma->dma_dev.device_alloc_chan_resources =
1531 tegra_dma_alloc_chan_resources;
1532 tdma->dma_dev.device_free_chan_resources =
1533 tegra_dma_free_chan_resources;
1534 tdma->dma_dev.device_prep_slave_sg = tegra_dma_prep_slave_sg;
1535 tdma->dma_dev.device_prep_dma_cyclic = tegra_dma_prep_dma_cyclic;
1536 tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1537 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1538 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1539 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1540 tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1541 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1542 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1543 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1544 tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1545 tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
1546 tdma->dma_dev.device_config = tegra_dma_slave_config;
1547 tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
1548 tdma->dma_dev.device_synchronize = tegra_dma_synchronize;
1549 tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
1550 tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
1551
1552 ret = dma_async_device_register(&tdma->dma_dev);
1553 if (ret < 0) {
1554 dev_err(&pdev->dev,
1555 "Tegra20 APB DMA driver registration failed %d\n", ret);
1556 goto err_pm_disable;
1557 }
1558
1559 ret = of_dma_controller_register(pdev->dev.of_node,
1560 tegra_dma_of_xlate, tdma);
1561 if (ret < 0) {
1562 dev_err(&pdev->dev,
1563 "Tegra20 APB DMA OF registration failed %d\n", ret);
1564 goto err_unregister_dma_dev;
1565 }
1566
1567 dev_info(&pdev->dev, "Tegra20 APB DMA driver registered %u channels\n",
1568 cdata->nr_channels);
1569
1570 return 0;
1571
1572 err_unregister_dma_dev:
1573 dma_async_device_unregister(&tdma->dma_dev);
1574
1575 err_pm_disable:
1576 pm_runtime_disable(&pdev->dev);
1577
1578 err_clk_unprepare:
1579 clk_unprepare(tdma->dma_clk);
1580
1581 return ret;
1582 }
1583
tegra_dma_remove(struct platform_device * pdev)1584 static int tegra_dma_remove(struct platform_device *pdev)
1585 {
1586 struct tegra_dma *tdma = platform_get_drvdata(pdev);
1587
1588 of_dma_controller_free(pdev->dev.of_node);
1589 dma_async_device_unregister(&tdma->dma_dev);
1590 pm_runtime_disable(&pdev->dev);
1591 clk_unprepare(tdma->dma_clk);
1592
1593 return 0;
1594 }
1595
tegra_dma_runtime_suspend(struct device * dev)1596 static int __maybe_unused tegra_dma_runtime_suspend(struct device *dev)
1597 {
1598 struct tegra_dma *tdma = dev_get_drvdata(dev);
1599
1600 clk_disable(tdma->dma_clk);
1601
1602 return 0;
1603 }
1604
tegra_dma_runtime_resume(struct device * dev)1605 static int __maybe_unused tegra_dma_runtime_resume(struct device *dev)
1606 {
1607 struct tegra_dma *tdma = dev_get_drvdata(dev);
1608
1609 return clk_enable(tdma->dma_clk);
1610 }
1611
tegra_dma_dev_suspend(struct device * dev)1612 static int __maybe_unused tegra_dma_dev_suspend(struct device *dev)
1613 {
1614 struct tegra_dma *tdma = dev_get_drvdata(dev);
1615 unsigned long flags;
1616 unsigned int i;
1617 bool busy;
1618
1619 for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1620 struct tegra_dma_channel *tdc = &tdma->channels[i];
1621
1622 tasklet_kill(&tdc->tasklet);
1623
1624 spin_lock_irqsave(&tdc->lock, flags);
1625 busy = tdc->busy;
1626 spin_unlock_irqrestore(&tdc->lock, flags);
1627
1628 if (busy) {
1629 dev_err(tdma->dev, "channel %u busy\n", i);
1630 return -EBUSY;
1631 }
1632 }
1633
1634 return pm_runtime_force_suspend(dev);
1635 }
1636
tegra_dma_dev_resume(struct device * dev)1637 static int __maybe_unused tegra_dma_dev_resume(struct device *dev)
1638 {
1639 struct tegra_dma *tdma = dev_get_drvdata(dev);
1640 int err;
1641
1642 err = tegra_dma_init_hw(tdma);
1643 if (err)
1644 return err;
1645
1646 return pm_runtime_force_resume(dev);
1647 }
1648
1649 static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
1650 SET_RUNTIME_PM_OPS(tegra_dma_runtime_suspend, tegra_dma_runtime_resume,
1651 NULL)
1652 SET_SYSTEM_SLEEP_PM_OPS(tegra_dma_dev_suspend, tegra_dma_dev_resume)
1653 };
1654
1655 static const struct of_device_id tegra_dma_of_match[] = {
1656 {
1657 .compatible = "nvidia,tegra148-apbdma",
1658 .data = &tegra148_dma_chip_data,
1659 }, {
1660 .compatible = "nvidia,tegra114-apbdma",
1661 .data = &tegra114_dma_chip_data,
1662 }, {
1663 .compatible = "nvidia,tegra30-apbdma",
1664 .data = &tegra30_dma_chip_data,
1665 }, {
1666 .compatible = "nvidia,tegra20-apbdma",
1667 .data = &tegra20_dma_chip_data,
1668 }, {
1669 },
1670 };
1671 MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
1672
1673 static struct platform_driver tegra_dmac_driver = {
1674 .driver = {
1675 .name = "tegra-apbdma",
1676 .pm = &tegra_dma_dev_pm_ops,
1677 .of_match_table = tegra_dma_of_match,
1678 },
1679 .probe = tegra_dma_probe,
1680 .remove = tegra_dma_remove,
1681 };
1682
1683 module_platform_driver(tegra_dmac_driver);
1684
1685 MODULE_DESCRIPTION("NVIDIA Tegra APB DMA Controller driver");
1686 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1687 MODULE_LICENSE("GPL v2");
1688
