1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Topcliff PCH DMA controller driver
4 * Copyright (c) 2010 Intel Corporation
5 * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
6 */
7
8#include <linux/dmaengine.h>
9#include <linux/dma-mapping.h>
10#include <linux/init.h>
11#include <linux/pci.h>
12#include <linux/slab.h>
13#include <linux/interrupt.h>
14#include <linux/module.h>
15#include <linux/pch_dma.h>
16
17#include "dmaengine.h"
18
19#define DRV_NAME "pch-dma"
20
21#define DMA_CTL0_DISABLE 0x0
22#define DMA_CTL0_SG 0x1
23#define DMA_CTL0_ONESHOT 0x2
24#define DMA_CTL0_MODE_MASK_BITS 0x3
25#define DMA_CTL0_DIR_SHIFT_BITS 2
26#define DMA_CTL0_BITS_PER_CH 4
27
28#define DMA_CTL2_START_SHIFT_BITS 8
29#define DMA_CTL2_IRQ_ENABLE_MASK ((1UL << DMA_CTL2_START_SHIFT_BITS) - 1)
30
31#define DMA_STATUS_IDLE 0x0
32#define DMA_STATUS_DESC_READ 0x1
33#define DMA_STATUS_WAIT 0x2
34#define DMA_STATUS_ACCESS 0x3
35#define DMA_STATUS_BITS_PER_CH 2
36#define DMA_STATUS_MASK_BITS 0x3
37#define DMA_STATUS_SHIFT_BITS 16
38#define DMA_STATUS_IRQ(x) (0x1 << (x))
39#define DMA_STATUS0_ERR(x) (0x1 << ((x) + 8))
40#define DMA_STATUS2_ERR(x) (0x1 << (x))
41
42#define DMA_DESC_WIDTH_SHIFT_BITS 12
43#define DMA_DESC_WIDTH_1_BYTE (0x3 << DMA_DESC_WIDTH_SHIFT_BITS)
44#define DMA_DESC_WIDTH_2_BYTES (0x2 << DMA_DESC_WIDTH_SHIFT_BITS)
45#define DMA_DESC_WIDTH_4_BYTES (0x0 << DMA_DESC_WIDTH_SHIFT_BITS)
46#define DMA_DESC_MAX_COUNT_1_BYTE 0x3FF
47#define DMA_DESC_MAX_COUNT_2_BYTES 0x3FF
48#define DMA_DESC_MAX_COUNT_4_BYTES 0x7FF
49#define DMA_DESC_END_WITHOUT_IRQ 0x0
50#define DMA_DESC_END_WITH_IRQ 0x1
51#define DMA_DESC_FOLLOW_WITHOUT_IRQ 0x2
52#define DMA_DESC_FOLLOW_WITH_IRQ 0x3
53
54#define MAX_CHAN_NR 12
55
56#define DMA_MASK_CTL0_MODE 0x33333333
57#define DMA_MASK_CTL2_MODE 0x00003333
58
59static unsigned int init_nr_desc_per_channel = 64;
60module_param(init_nr_desc_per_channel, uint, 0644);
61MODULE_PARM_DESC(init_nr_desc_per_channel,
62 "initial descriptors per channel (default: 64)");
63
64struct pch_dma_desc_regs {
65 u32 dev_addr;
66 u32 mem_addr;
67 u32 size;
68 u32 next;
69};
70
71struct pch_dma_regs {
72 u32 dma_ctl0;
73 u32 dma_ctl1;
74 u32 dma_ctl2;
75 u32 dma_ctl3;
76 u32 dma_sts0;
77 u32 dma_sts1;
78 u32 dma_sts2;
79 u32 reserved3;
80 struct pch_dma_desc_regs desc[MAX_CHAN_NR];
81};
82
83struct pch_dma_desc {
84 struct pch_dma_desc_regs regs;
85 struct dma_async_tx_descriptor txd;
86 struct list_head desc_node;
87 struct list_head tx_list;
88};
89
90struct pch_dma_chan {
91 struct dma_chan chan;
92 void __iomem *membase;
93 enum dma_transfer_direction dir;
94 struct tasklet_struct tasklet;
95 unsigned long err_status;
96
97 spinlock_t lock;
98
99 struct list_head active_list;
100 struct list_head queue;
101 struct list_head free_list;
102 unsigned int descs_allocated;
103};
104
105#define PDC_DEV_ADDR 0x00
106#define PDC_MEM_ADDR 0x04
107#define PDC_SIZE 0x08
108#define PDC_NEXT 0x0C
109
110#define channel_readl(pdc, name) \
111 readl((pdc)->membase + PDC_##name)
112#define channel_writel(pdc, name, val) \
113 writel((val), (pdc)->membase + PDC_##name)
114
115struct pch_dma {
116 struct dma_device dma;
117 void __iomem *membase;
118 struct dma_pool *pool;
119 struct pch_dma_regs regs;
120 struct pch_dma_desc_regs ch_regs[MAX_CHAN_NR];
121 struct pch_dma_chan channels[MAX_CHAN_NR];
122};
123
124#define PCH_DMA_CTL0 0x00
125#define PCH_DMA_CTL1 0x04
126#define PCH_DMA_CTL2 0x08
127#define PCH_DMA_CTL3 0x0C
128#define PCH_DMA_STS0 0x10
129#define PCH_DMA_STS1 0x14
130#define PCH_DMA_STS2 0x18
131
132#define dma_readl(pd, name) \
133 readl((pd)->membase + PCH_DMA_##name)
134#define dma_writel(pd, name, val) \
135 writel((val), (pd)->membase + PCH_DMA_##name)
136
137static inline
138struct pch_dma_desc *to_pd_desc(struct dma_async_tx_descriptor *txd)
139{
140 return container_of(txd, struct pch_dma_desc, txd);
141}
142
143static inline struct pch_dma_chan *to_pd_chan(struct dma_chan *chan)
144{
145 return container_of(chan, struct pch_dma_chan, chan);
146}
147
148static inline struct pch_dma *to_pd(struct dma_device *ddev)
149{
150 return container_of(ddev, struct pch_dma, dma);
151}
152
153static inline struct device *chan2dev(struct dma_chan *chan)
154{
155 return &chan->dev->device;
156}
157
158static inline
159struct pch_dma_desc *pdc_first_active(struct pch_dma_chan *pd_chan)
160{
161 return list_first_entry(&pd_chan->active_list,
162 struct pch_dma_desc, desc_node);
163}
164
165static inline
166struct pch_dma_desc *pdc_first_queued(struct pch_dma_chan *pd_chan)
167{
168 return list_first_entry(&pd_chan->queue,
169 struct pch_dma_desc, desc_node);
170}
171
172static void pdc_enable_irq(struct dma_chan *chan, int enable)
173{
174 struct pch_dma *pd = to_pd(ddev: chan->device);
175 u32 val;
176 int pos;
177
178 if (chan->chan_id < 8)
179 pos = chan->chan_id;
180 else
181 pos = chan->chan_id + 8;
182
183 val = dma_readl(pd, CTL2);
184
185 if (enable)
186 val |= 0x1 << pos;
187 else
188 val &= ~(0x1 << pos);
189
190 dma_writel(pd, CTL2, val);
191
192 dev_dbg(chan2dev(chan), "pdc_enable_irq: chan %d -> %x\n",
193 chan->chan_id, val);
194}
195
196static void pdc_set_dir(struct dma_chan *chan)
197{
198 struct pch_dma_chan *pd_chan = to_pd_chan(chan);
199 struct pch_dma *pd = to_pd(ddev: chan->device);
200 u32 val;
201 u32 mask_mode;
202 u32 mask_ctl;
203
204 if (chan->chan_id < 8) {
205 val = dma_readl(pd, CTL0);
206
207 mask_mode = DMA_CTL0_MODE_MASK_BITS <<
208 (DMA_CTL0_BITS_PER_CH * chan->chan_id);
209 mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
210 (DMA_CTL0_BITS_PER_CH * chan->chan_id));
211 val &= mask_mode;
212 if (pd_chan->dir == DMA_MEM_TO_DEV)
213 val |= 0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
214 DMA_CTL0_DIR_SHIFT_BITS);
215 else
216 val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
217 DMA_CTL0_DIR_SHIFT_BITS));
218
219 val |= mask_ctl;
220 dma_writel(pd, CTL0, val);
221 } else {
222 int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
223 val = dma_readl(pd, CTL3);
224
225 mask_mode = DMA_CTL0_MODE_MASK_BITS <<
226 (DMA_CTL0_BITS_PER_CH * ch);
227 mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
228 (DMA_CTL0_BITS_PER_CH * ch));
229 val &= mask_mode;
230 if (pd_chan->dir == DMA_MEM_TO_DEV)
231 val |= 0x1 << (DMA_CTL0_BITS_PER_CH * ch +
232 DMA_CTL0_DIR_SHIFT_BITS);
233 else
234 val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * ch +
235 DMA_CTL0_DIR_SHIFT_BITS));
236 val |= mask_ctl;
237 dma_writel(pd, CTL3, val);
238 }
239
240 dev_dbg(chan2dev(chan), "pdc_set_dir: chan %d -> %x\n",
241 chan->chan_id, val);
242}
243
244static void pdc_set_mode(struct dma_chan *chan, u32 mode)
245{
246 struct pch_dma *pd = to_pd(ddev: chan->device);
247 u32 val;
248 u32 mask_ctl;
249 u32 mask_dir;
250
251 if (chan->chan_id < 8) {
252 mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
253 (DMA_CTL0_BITS_PER_CH * chan->chan_id));
254 mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +\
255 DMA_CTL0_DIR_SHIFT_BITS);
256 val = dma_readl(pd, CTL0);
257 val &= mask_dir;
258 val |= mode << (DMA_CTL0_BITS_PER_CH * chan->chan_id);
259 val |= mask_ctl;
260 dma_writel(pd, CTL0, val);
261 } else {
262 int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
263 mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
264 (DMA_CTL0_BITS_PER_CH * ch));
265 mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * ch +\
266 DMA_CTL0_DIR_SHIFT_BITS);
267 val = dma_readl(pd, CTL3);
268 val &= mask_dir;
269 val |= mode << (DMA_CTL0_BITS_PER_CH * ch);
270 val |= mask_ctl;
271 dma_writel(pd, CTL3, val);
272 }
273
274 dev_dbg(chan2dev(chan), "pdc_set_mode: chan %d -> %x\n",
275 chan->chan_id, val);
276}
277
278static u32 pdc_get_status0(struct pch_dma_chan *pd_chan)
279{
280 struct pch_dma *pd = to_pd(ddev: pd_chan->chan.device);
281 u32 val;
282
283 val = dma_readl(pd, STS0);
284 return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
285 DMA_STATUS_BITS_PER_CH * pd_chan->chan.chan_id));
286}
287
288static u32 pdc_get_status2(struct pch_dma_chan *pd_chan)
289{
290 struct pch_dma *pd = to_pd(ddev: pd_chan->chan.device);
291 u32 val;
292
293 val = dma_readl(pd, STS2);
294 return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
295 DMA_STATUS_BITS_PER_CH * (pd_chan->chan.chan_id - 8)));
296}
297
298static bool pdc_is_idle(struct pch_dma_chan *pd_chan)
299{
300 u32 sts;
301
302 if (pd_chan->chan.chan_id < 8)
303 sts = pdc_get_status0(pd_chan);
304 else
305 sts = pdc_get_status2(pd_chan);
306
307
308 if (sts == DMA_STATUS_IDLE)
309 return true;
310 else
311 return false;
312}
313
314static void pdc_dostart(struct pch_dma_chan *pd_chan, struct pch_dma_desc* desc)
315{
316 if (!pdc_is_idle(pd_chan)) {
317 dev_err(chan2dev(&pd_chan->chan),
318 "BUG: Attempt to start non-idle channel\n");
319 return;
320 }
321
322 dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> dev_addr: %x\n",
323 pd_chan->chan.chan_id, desc->regs.dev_addr);
324 dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> mem_addr: %x\n",
325 pd_chan->chan.chan_id, desc->regs.mem_addr);
326 dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> size: %x\n",
327 pd_chan->chan.chan_id, desc->regs.size);
328 dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> next: %x\n",
329 pd_chan->chan.chan_id, desc->regs.next);
330
331 if (list_empty(head: &desc->tx_list)) {
332 channel_writel(pd_chan, DEV_ADDR, desc->regs.dev_addr);
333 channel_writel(pd_chan, MEM_ADDR, desc->regs.mem_addr);
334 channel_writel(pd_chan, SIZE, desc->regs.size);
335 channel_writel(pd_chan, NEXT, desc->regs.next);
336 pdc_set_mode(chan: &pd_chan->chan, DMA_CTL0_ONESHOT);
337 } else {
338 channel_writel(pd_chan, NEXT, desc->txd.phys);
339 pdc_set_mode(chan: &pd_chan->chan, DMA_CTL0_SG);
340 }
341}
342
343static void pdc_chain_complete(struct pch_dma_chan *pd_chan,
344 struct pch_dma_desc *desc)
345{
346 struct dma_async_tx_descriptor *txd = &desc->txd;
347 struct dmaengine_desc_callback cb;
348
349 dmaengine_desc_get_callback(tx: txd, cb: &cb);
350 list_splice_init(list: &desc->tx_list, head: &pd_chan->free_list);
351 list_move(list: &desc->desc_node, head: &pd_chan->free_list);
352
353 dmaengine_desc_callback_invoke(cb: &cb, NULL);
354}
355
356static void pdc_complete_all(struct pch_dma_chan *pd_chan)
357{
358 struct pch_dma_desc *desc, *_d;
359 LIST_HEAD(list);
360
361 BUG_ON(!pdc_is_idle(pd_chan));
362
363 if (!list_empty(head: &pd_chan->queue))
364 pdc_dostart(pd_chan, desc: pdc_first_queued(pd_chan));
365
366 list_splice_init(list: &pd_chan->active_list, head: &list);
367 list_splice_init(list: &pd_chan->queue, head: &pd_chan->active_list);
368
369 list_for_each_entry_safe(desc, _d, &list, desc_node)
370 pdc_chain_complete(pd_chan, desc);
371}
372
373static void pdc_handle_error(struct pch_dma_chan *pd_chan)
374{
375 struct pch_dma_desc *bad_desc;
376
377 bad_desc = pdc_first_active(pd_chan);
378 list_del(entry: &bad_desc->desc_node);
379
380 list_splice_init(list: &pd_chan->queue, head: pd_chan->active_list.prev);
381
382 if (!list_empty(head: &pd_chan->active_list))
383 pdc_dostart(pd_chan, desc: pdc_first_active(pd_chan));
384
385 dev_crit(chan2dev(&pd_chan->chan), "Bad descriptor submitted\n");
386 dev_crit(chan2dev(&pd_chan->chan), "descriptor cookie: %d\n",
387 bad_desc->txd.cookie);
388
389 pdc_chain_complete(pd_chan, desc: bad_desc);
390}
391
392static void pdc_advance_work(struct pch_dma_chan *pd_chan)
393{
394 if (list_empty(head: &pd_chan->active_list) ||
395 list_is_singular(head: &pd_chan->active_list)) {
396 pdc_complete_all(pd_chan);
397 } else {
398 pdc_chain_complete(pd_chan, desc: pdc_first_active(pd_chan));
399 pdc_dostart(pd_chan, desc: pdc_first_active(pd_chan));
400 }
401}
402
403static dma_cookie_t pd_tx_submit(struct dma_async_tx_descriptor *txd)
404{
405 struct pch_dma_desc *desc = to_pd_desc(txd);
406 struct pch_dma_chan *pd_chan = to_pd_chan(chan: txd->chan);
407
408 spin_lock(lock: &pd_chan->lock);
409
410 if (list_empty(head: &pd_chan->active_list)) {
411 list_add_tail(new: &desc->desc_node, head: &pd_chan->active_list);
412 pdc_dostart(pd_chan, desc);
413 } else {
414 list_add_tail(new: &desc->desc_node, head: &pd_chan->queue);
415 }
416
417 spin_unlock(lock: &pd_chan->lock);
418 return 0;
419}
420
421static struct pch_dma_desc *pdc_alloc_desc(struct dma_chan *chan, gfp_t flags)
422{
423 struct pch_dma_desc *desc = NULL;
424 struct pch_dma *pd = to_pd(ddev: chan->device);
425 dma_addr_t addr;
426
427 desc = dma_pool_zalloc(pool: pd->pool, mem_flags: flags, handle: &addr);
428 if (desc) {
429 INIT_LIST_HEAD(list: &desc->tx_list);
430 dma_async_tx_descriptor_init(tx: &desc->txd, chan);
431 desc->txd.tx_submit = pd_tx_submit;
432 desc->txd.flags = DMA_CTRL_ACK;
433 desc->txd.phys = addr;
434 }
435
436 return desc;
437}
438
439static struct pch_dma_desc *pdc_desc_get(struct pch_dma_chan *pd_chan)
440{
441 struct pch_dma_desc *desc, *_d;
442 struct pch_dma_desc *ret = NULL;
443 int i = 0;
444
445 spin_lock(lock: &pd_chan->lock);
446 list_for_each_entry_safe(desc, _d, &pd_chan->free_list, desc_node) {
447 i++;
448 if (async_tx_test_ack(tx: &desc->txd)) {
449 list_del(entry: &desc->desc_node);
450 ret = desc;
451 break;
452 }
453 dev_dbg(chan2dev(&pd_chan->chan), "desc %p not ACKed\n", desc);
454 }
455 spin_unlock(lock: &pd_chan->lock);
456 dev_dbg(chan2dev(&pd_chan->chan), "scanned %d descriptors\n", i);
457
458 if (!ret) {
459 ret = pdc_alloc_desc(chan: &pd_chan->chan, GFP_ATOMIC);
460 if (ret) {
461 spin_lock(lock: &pd_chan->lock);
462 pd_chan->descs_allocated++;
463 spin_unlock(lock: &pd_chan->lock);
464 } else {
465 dev_err(chan2dev(&pd_chan->chan),
466 "failed to alloc desc\n");
467 }
468 }
469
470 return ret;
471}
472
473static void pdc_desc_put(struct pch_dma_chan *pd_chan,
474 struct pch_dma_desc *desc)
475{
476 if (desc) {
477 spin_lock(lock: &pd_chan->lock);
478 list_splice_init(list: &desc->tx_list, head: &pd_chan->free_list);
479 list_add(new: &desc->desc_node, head: &pd_chan->free_list);
480 spin_unlock(lock: &pd_chan->lock);
481 }
482}
483
484static int pd_alloc_chan_resources(struct dma_chan *chan)
485{
486 struct pch_dma_chan *pd_chan = to_pd_chan(chan);
487 struct pch_dma_desc *desc;
488 LIST_HEAD(tmp_list);
489 int i;
490
491 if (!pdc_is_idle(pd_chan)) {
492 dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
493 return -EIO;
494 }
495
496 if (!list_empty(head: &pd_chan->free_list))
497 return pd_chan->descs_allocated;
498
499 for (i = 0; i < init_nr_desc_per_channel; i++) {
500 desc = pdc_alloc_desc(chan, GFP_KERNEL);
501
502 if (!desc) {
503 dev_warn(chan2dev(chan),
504 "Only allocated %d initial descriptors\n", i);
505 break;
506 }
507
508 list_add_tail(new: &desc->desc_node, head: &tmp_list);
509 }
510
511 spin_lock_irq(lock: &pd_chan->lock);
512 list_splice(list: &tmp_list, head: &pd_chan->free_list);
513 pd_chan->descs_allocated = i;
514 dma_cookie_init(chan);
515 spin_unlock_irq(lock: &pd_chan->lock);
516
517 pdc_enable_irq(chan, enable: 1);
518
519 return pd_chan->descs_allocated;
520}
521
522static void pd_free_chan_resources(struct dma_chan *chan)
523{
524 struct pch_dma_chan *pd_chan = to_pd_chan(chan);
525 struct pch_dma *pd = to_pd(ddev: chan->device);
526 struct pch_dma_desc *desc, *_d;
527 LIST_HEAD(tmp_list);
528
529 BUG_ON(!pdc_is_idle(pd_chan));
530 BUG_ON(!list_empty(&pd_chan->active_list));
531 BUG_ON(!list_empty(&pd_chan->queue));
532
533 spin_lock_irq(lock: &pd_chan->lock);
534 list_splice_init(list: &pd_chan->free_list, head: &tmp_list);
535 pd_chan->descs_allocated = 0;
536 spin_unlock_irq(lock: &pd_chan->lock);
537
538 list_for_each_entry_safe(desc, _d, &tmp_list, desc_node)
539 dma_pool_free(pool: pd->pool, vaddr: desc, addr: desc->txd.phys);
540
541 pdc_enable_irq(chan, enable: 0);
542}
543
544static enum dma_status pd_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
545 struct dma_tx_state *txstate)
546{
547 return dma_cookie_status(chan, cookie, state: txstate);
548}
549
550static void pd_issue_pending(struct dma_chan *chan)
551{
552 struct pch_dma_chan *pd_chan = to_pd_chan(chan);
553
554 if (pdc_is_idle(pd_chan)) {
555 spin_lock(lock: &pd_chan->lock);
556 pdc_advance_work(pd_chan);
557 spin_unlock(lock: &pd_chan->lock);
558 }
559}
560
561static struct dma_async_tx_descriptor *pd_prep_slave_sg(struct dma_chan *chan,
562 struct scatterlist *sgl, unsigned int sg_len,
563 enum dma_transfer_direction direction, unsigned long flags,
564 void *context)
565{
566 struct pch_dma_chan *pd_chan = to_pd_chan(chan);
567 struct pch_dma_slave *pd_slave = chan->private;
568 struct pch_dma_desc *first = NULL;
569 struct pch_dma_desc *prev = NULL;
570 struct pch_dma_desc *desc = NULL;
571 struct scatterlist *sg;
572 dma_addr_t reg;
573 int i;
574
575 if (unlikely(!sg_len)) {
576 dev_info(chan2dev(chan), "prep_slave_sg: length is zero!\n");
577 return NULL;
578 }
579
580 if (direction == DMA_DEV_TO_MEM)
581 reg = pd_slave->rx_reg;
582 else if (direction == DMA_MEM_TO_DEV)
583 reg = pd_slave->tx_reg;
584 else
585 return NULL;
586
587 pd_chan->dir = direction;
588 pdc_set_dir(chan);
589
590 for_each_sg(sgl, sg, sg_len, i) {
591 desc = pdc_desc_get(pd_chan);
592
593 if (!desc)
594 goto err_desc_get;
595
596 desc->regs.dev_addr = reg;
597 desc->regs.mem_addr = sg_dma_address(sg);
598 desc->regs.size = sg_dma_len(sg);
599 desc->regs.next = DMA_DESC_FOLLOW_WITHOUT_IRQ;
600
601 switch (pd_slave->width) {
602 case PCH_DMA_WIDTH_1_BYTE:
603 if (desc->regs.size > DMA_DESC_MAX_COUNT_1_BYTE)
604 goto err_desc_get;
605 desc->regs.size |= DMA_DESC_WIDTH_1_BYTE;
606 break;
607 case PCH_DMA_WIDTH_2_BYTES:
608 if (desc->regs.size > DMA_DESC_MAX_COUNT_2_BYTES)
609 goto err_desc_get;
610 desc->regs.size |= DMA_DESC_WIDTH_2_BYTES;
611 break;
612 case PCH_DMA_WIDTH_4_BYTES:
613 if (desc->regs.size > DMA_DESC_MAX_COUNT_4_BYTES)
614 goto err_desc_get;
615 desc->regs.size |= DMA_DESC_WIDTH_4_BYTES;
616 break;
617 default:
618 goto err_desc_get;
619 }
620
621 if (!first) {
622 first = desc;
623 } else {
624 prev->regs.next |= desc->txd.phys;
625 list_add_tail(new: &desc->desc_node, head: &first->tx_list);
626 }
627
628 prev = desc;
629 }
630
631 if (flags & DMA_PREP_INTERRUPT)
632 desc->regs.next = DMA_DESC_END_WITH_IRQ;
633 else
634 desc->regs.next = DMA_DESC_END_WITHOUT_IRQ;
635
636 first->txd.cookie = -EBUSY;
637 desc->txd.flags = flags;
638
639 return &first->txd;
640
641err_desc_get:
642 dev_err(chan2dev(chan), "failed to get desc or wrong parameters\n");
643 pdc_desc_put(pd_chan, desc: first);
644 return NULL;
645}
646
647static int pd_device_terminate_all(struct dma_chan *chan)
648{
649 struct pch_dma_chan *pd_chan = to_pd_chan(chan);
650 struct pch_dma_desc *desc, *_d;
651 LIST_HEAD(list);
652
653 spin_lock_irq(lock: &pd_chan->lock);
654
655 pdc_set_mode(chan: &pd_chan->chan, DMA_CTL0_DISABLE);
656
657 list_splice_init(list: &pd_chan->active_list, head: &list);
658 list_splice_init(list: &pd_chan->queue, head: &list);
659
660 list_for_each_entry_safe(desc, _d, &list, desc_node)
661 pdc_chain_complete(pd_chan, desc);
662
663 spin_unlock_irq(lock: &pd_chan->lock);
664
665 return 0;
666}
667
668static void pdc_tasklet(struct tasklet_struct *t)
669{
670 struct pch_dma_chan *pd_chan = from_tasklet(pd_chan, t, tasklet);
671 unsigned long flags;
672
673 if (!pdc_is_idle(pd_chan)) {
674 dev_err(chan2dev(&pd_chan->chan),
675 "BUG: handle non-idle channel in tasklet\n");
676 return;
677 }
678
679 spin_lock_irqsave(&pd_chan->lock, flags);
680 if (test_and_clear_bit(nr: 0, addr: &pd_chan->err_status))
681 pdc_handle_error(pd_chan);
682 else
683 pdc_advance_work(pd_chan);
684 spin_unlock_irqrestore(lock: &pd_chan->lock, flags);
685}
686
687static irqreturn_t pd_irq(int irq, void *devid)
688{
689 struct pch_dma *pd = (struct pch_dma *)devid;
690 struct pch_dma_chan *pd_chan;
691 u32 sts0;
692 u32 sts2;
693 int i;
694 int ret0 = IRQ_NONE;
695 int ret2 = IRQ_NONE;
696
697 sts0 = dma_readl(pd, STS0);
698 sts2 = dma_readl(pd, STS2);
699
700 dev_dbg(pd->dma.dev, "pd_irq sts0: %x\n", sts0);
701
702 for (i = 0; i < pd->dma.chancnt; i++) {
703 pd_chan = &pd->channels[i];
704
705 if (i < 8) {
706 if (sts0 & DMA_STATUS_IRQ(i)) {
707 if (sts0 & DMA_STATUS0_ERR(i))
708 set_bit(nr: 0, addr: &pd_chan->err_status);
709
710 tasklet_schedule(t: &pd_chan->tasklet);
711 ret0 = IRQ_HANDLED;
712 }
713 } else {
714 if (sts2 & DMA_STATUS_IRQ(i - 8)) {
715 if (sts2 & DMA_STATUS2_ERR(i))
716 set_bit(nr: 0, addr: &pd_chan->err_status);
717
718 tasklet_schedule(t: &pd_chan->tasklet);
719 ret2 = IRQ_HANDLED;
720 }
721 }
722 }
723
724 /* clear interrupt bits in status register */
725 if (ret0)
726 dma_writel(pd, STS0, sts0);
727 if (ret2)
728 dma_writel(pd, STS2, sts2);
729
730 return ret0 | ret2;
731}
732
733static void __maybe_unused pch_dma_save_regs(struct pch_dma *pd)
734{
735 struct pch_dma_chan *pd_chan;
736 struct dma_chan *chan, *_c;
737 int i = 0;
738
739 pd->regs.dma_ctl0 = dma_readl(pd, CTL0);
740 pd->regs.dma_ctl1 = dma_readl(pd, CTL1);
741 pd->regs.dma_ctl2 = dma_readl(pd, CTL2);
742 pd->regs.dma_ctl3 = dma_readl(pd, CTL3);
743
744 list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
745 pd_chan = to_pd_chan(chan);
746
747 pd->ch_regs[i].dev_addr = channel_readl(pd_chan, DEV_ADDR);
748 pd->ch_regs[i].mem_addr = channel_readl(pd_chan, MEM_ADDR);
749 pd->ch_regs[i].size = channel_readl(pd_chan, SIZE);
750 pd->ch_regs[i].next = channel_readl(pd_chan, NEXT);
751
752 i++;
753 }
754}
755
756static void __maybe_unused pch_dma_restore_regs(struct pch_dma *pd)
757{
758 struct pch_dma_chan *pd_chan;
759 struct dma_chan *chan, *_c;
760 int i = 0;
761
762 dma_writel(pd, CTL0, pd->regs.dma_ctl0);
763 dma_writel(pd, CTL1, pd->regs.dma_ctl1);
764 dma_writel(pd, CTL2, pd->regs.dma_ctl2);
765 dma_writel(pd, CTL3, pd->regs.dma_ctl3);
766
767 list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
768 pd_chan = to_pd_chan(chan);
769
770 channel_writel(pd_chan, DEV_ADDR, pd->ch_regs[i].dev_addr);
771 channel_writel(pd_chan, MEM_ADDR, pd->ch_regs[i].mem_addr);
772 channel_writel(pd_chan, SIZE, pd->ch_regs[i].size);
773 channel_writel(pd_chan, NEXT, pd->ch_regs[i].next);
774
775 i++;
776 }
777}
778
779static int __maybe_unused pch_dma_suspend(struct device *dev)
780{
781 struct pch_dma *pd = dev_get_drvdata(dev);
782
783 if (pd)
784 pch_dma_save_regs(pd);
785
786 return 0;
787}
788
789static int __maybe_unused pch_dma_resume(struct device *dev)
790{
791 struct pch_dma *pd = dev_get_drvdata(dev);
792
793 if (pd)
794 pch_dma_restore_regs(pd);
795
796 return 0;
797}
798
799static int pch_dma_probe(struct pci_dev *pdev,
800 const struct pci_device_id *id)
801{
802 struct pch_dma *pd;
803 struct pch_dma_regs *regs;
804 unsigned int nr_channels;
805 int err;
806 int i;
807
808 nr_channels = id->driver_data;
809 pd = kzalloc(sizeof(*pd), GFP_KERNEL);
810 if (!pd)
811 return -ENOMEM;
812
813 pci_set_drvdata(pdev, data: pd);
814
815 err = pci_enable_device(dev: pdev);
816 if (err) {
817 dev_err(&pdev->dev, "Cannot enable PCI device\n");
818 goto err_free_mem;
819 }
820
821 if (!(pci_resource_flags(pdev, 1) & IORESOURCE_MEM)) {
822 dev_err(&pdev->dev, "Cannot find proper base address\n");
823 err = -ENODEV;
824 goto err_disable_pdev;
825 }
826
827 err = pci_request_regions(pdev, DRV_NAME);
828 if (err) {
829 dev_err(&pdev->dev, "Cannot obtain PCI resources\n");
830 goto err_disable_pdev;
831 }
832
833 err = dma_set_mask(dev: &pdev->dev, DMA_BIT_MASK(32));
834 if (err) {
835 dev_err(&pdev->dev, "Cannot set proper DMA config\n");
836 goto err_free_res;
837 }
838
839 regs = pd->membase = pci_iomap(dev: pdev, bar: 1, max: 0);
840 if (!pd->membase) {
841 dev_err(&pdev->dev, "Cannot map MMIO registers\n");
842 err = -ENOMEM;
843 goto err_free_res;
844 }
845
846 pci_set_master(dev: pdev);
847 pd->dma.dev = &pdev->dev;
848
849 err = request_irq(irq: pdev->irq, handler: pd_irq, IRQF_SHARED, DRV_NAME, dev: pd);
850 if (err) {
851 dev_err(&pdev->dev, "Failed to request IRQ\n");
852 goto err_iounmap;
853 }
854
855 pd->pool = dma_pool_create(name: "pch_dma_desc_pool", dev: &pdev->dev,
856 size: sizeof(struct pch_dma_desc), align: 4, boundary: 0);
857 if (!pd->pool) {
858 dev_err(&pdev->dev, "Failed to alloc DMA descriptors\n");
859 err = -ENOMEM;
860 goto err_free_irq;
861 }
862
863
864 INIT_LIST_HEAD(list: &pd->dma.channels);
865
866 for (i = 0; i < nr_channels; i++) {
867 struct pch_dma_chan *pd_chan = &pd->channels[i];
868
869 pd_chan->chan.device = &pd->dma;
870 dma_cookie_init(chan: &pd_chan->chan);
871
872 pd_chan->membase = &regs->desc[i];
873
874 spin_lock_init(&pd_chan->lock);
875
876 INIT_LIST_HEAD(list: &pd_chan->active_list);
877 INIT_LIST_HEAD(list: &pd_chan->queue);
878 INIT_LIST_HEAD(list: &pd_chan->free_list);
879
880 tasklet_setup(t: &pd_chan->tasklet, callback: pdc_tasklet);
881 list_add_tail(new: &pd_chan->chan.device_node, head: &pd->dma.channels);
882 }
883
884 dma_cap_zero(pd->dma.cap_mask);
885 dma_cap_set(DMA_PRIVATE, pd->dma.cap_mask);
886 dma_cap_set(DMA_SLAVE, pd->dma.cap_mask);
887
888 pd->dma.device_alloc_chan_resources = pd_alloc_chan_resources;
889 pd->dma.device_free_chan_resources = pd_free_chan_resources;
890 pd->dma.device_tx_status = pd_tx_status;
891 pd->dma.device_issue_pending = pd_issue_pending;
892 pd->dma.device_prep_slave_sg = pd_prep_slave_sg;
893 pd->dma.device_terminate_all = pd_device_terminate_all;
894
895 err = dma_async_device_register(device: &pd->dma);
896 if (err) {
897 dev_err(&pdev->dev, "Failed to register DMA device\n");
898 goto err_free_pool;
899 }
900
901 return 0;
902
903err_free_pool:
904 dma_pool_destroy(pool: pd->pool);
905err_free_irq:
906 free_irq(pdev->irq, pd);
907err_iounmap:
908 pci_iounmap(dev: pdev, pd->membase);
909err_free_res:
910 pci_release_regions(pdev);
911err_disable_pdev:
912 pci_disable_device(dev: pdev);
913err_free_mem:
914 kfree(objp: pd);
915 return err;
916}
917
918static void pch_dma_remove(struct pci_dev *pdev)
919{
920 struct pch_dma *pd = pci_get_drvdata(pdev);
921 struct pch_dma_chan *pd_chan;
922 struct dma_chan *chan, *_c;
923
924 if (pd) {
925 dma_async_device_unregister(device: &pd->dma);
926
927 free_irq(pdev->irq, pd);
928
929 list_for_each_entry_safe(chan, _c, &pd->dma.channels,
930 device_node) {
931 pd_chan = to_pd_chan(chan);
932
933 tasklet_kill(t: &pd_chan->tasklet);
934 }
935
936 dma_pool_destroy(pool: pd->pool);
937 pci_iounmap(dev: pdev, pd->membase);
938 pci_release_regions(pdev);
939 pci_disable_device(dev: pdev);
940 kfree(objp: pd);
941 }
942}
943
944/* PCI Device ID of DMA device */
945#define PCI_DEVICE_ID_EG20T_PCH_DMA_8CH 0x8810
946#define PCI_DEVICE_ID_EG20T_PCH_DMA_4CH 0x8815
947#define PCI_DEVICE_ID_ML7213_DMA1_8CH 0x8026
948#define PCI_DEVICE_ID_ML7213_DMA2_8CH 0x802B
949#define PCI_DEVICE_ID_ML7213_DMA3_4CH 0x8034
950#define PCI_DEVICE_ID_ML7213_DMA4_12CH 0x8032
951#define PCI_DEVICE_ID_ML7223_DMA1_4CH 0x800B
952#define PCI_DEVICE_ID_ML7223_DMA2_4CH 0x800E
953#define PCI_DEVICE_ID_ML7223_DMA3_4CH 0x8017
954#define PCI_DEVICE_ID_ML7223_DMA4_4CH 0x803B
955#define PCI_DEVICE_ID_ML7831_DMA1_8CH 0x8810
956#define PCI_DEVICE_ID_ML7831_DMA2_4CH 0x8815
957
958static const struct pci_device_id pch_dma_id_table[] = {
959 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_8CH), 8 },
960 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_4CH), 4 },
961 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA1_8CH), 8}, /* UART Video */
962 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA2_8CH), 8}, /* PCMIF SPI */
963 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA3_4CH), 4}, /* FPGA */
964 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA4_12CH), 12}, /* I2S */
965 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA1_4CH), 4}, /* UART */
966 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA2_4CH), 4}, /* Video SPI */
967 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA3_4CH), 4}, /* Security */
968 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA4_4CH), 4}, /* FPGA */
969 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA1_8CH), 8}, /* UART */
970 { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA2_4CH), 4}, /* SPI */
971 { 0, },
972};
973
974static SIMPLE_DEV_PM_OPS(pch_dma_pm_ops, pch_dma_suspend, pch_dma_resume);
975
976static struct pci_driver pch_dma_driver = {
977 .name = DRV_NAME,
978 .id_table = pch_dma_id_table,
979 .probe = pch_dma_probe,
980 .remove = pch_dma_remove,
981 .driver.pm = &pch_dma_pm_ops,
982};
983
984module_pci_driver(pch_dma_driver);
985
986MODULE_DESCRIPTION("Intel EG20T PCH / LAPIS Semicon ML7213/ML7223/ML7831 IOH "
987 "DMA controller driver");
988MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
989MODULE_LICENSE("GPL v2");
990MODULE_DEVICE_TABLE(pci, pch_dma_id_table);
991

source code of linux/drivers/dma/pch_dma.c