Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/drivers/dma/pch_dma.c

  1 /*
  2  * Topcliff PCH DMA controller driver
  3  * Copyright (c) 2010 Intel Corporation
  4  * Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
  5  *
  6  * This program is free software; you can redistribute it and/or modify
  7  * it under the terms of the GNU General Public License version 2 as
  8  * published by the Free Software Foundation.
  9  *
 10  * This program is distributed in the hope that it will be useful,
 11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13  * GNU General Public License for more details.
 14  */
 15 
 16 #include <linux/dmaengine.h>
 17 #include <linux/dma-mapping.h>
 18 #include <linux/init.h>
 19 #include <linux/pci.h>
 20 #include <linux/slab.h>
 21 #include <linux/interrupt.h>
 22 #include <linux/module.h>
 23 #include <linux/pch_dma.h>
 24 
 25 #include "dmaengine.h"
 26 
 27 #define DRV_NAME "pch-dma"
 28 
 29 #define DMA_CTL0_DISABLE                0x0
 30 #define DMA_CTL0_SG                     0x1
 31 #define DMA_CTL0_ONESHOT                0x2
 32 #define DMA_CTL0_MODE_MASK_BITS         0x3
 33 #define DMA_CTL0_DIR_SHIFT_BITS         2
 34 #define DMA_CTL0_BITS_PER_CH            4
 35 
 36 #define DMA_CTL2_START_SHIFT_BITS       8
 37 #define DMA_CTL2_IRQ_ENABLE_MASK        ((1UL << DMA_CTL2_START_SHIFT_BITS) - 1)
 38 
 39 #define DMA_STATUS_IDLE                 0x0
 40 #define DMA_STATUS_DESC_READ            0x1
 41 #define DMA_STATUS_WAIT                 0x2
 42 #define DMA_STATUS_ACCESS               0x3
 43 #define DMA_STATUS_BITS_PER_CH          2
 44 #define DMA_STATUS_MASK_BITS            0x3
 45 #define DMA_STATUS_SHIFT_BITS           16
 46 #define DMA_STATUS_IRQ(x)               (0x1 << (x))
 47 #define DMA_STATUS0_ERR(x)              (0x1 << ((x) + 8))
 48 #define DMA_STATUS2_ERR(x)              (0x1 << (x))
 49 
 50 #define DMA_DESC_WIDTH_SHIFT_BITS       12
 51 #define DMA_DESC_WIDTH_1_BYTE           (0x3 << DMA_DESC_WIDTH_SHIFT_BITS)
 52 #define DMA_DESC_WIDTH_2_BYTES          (0x2 << DMA_DESC_WIDTH_SHIFT_BITS)
 53 #define DMA_DESC_WIDTH_4_BYTES          (0x0 << DMA_DESC_WIDTH_SHIFT_BITS)
 54 #define DMA_DESC_MAX_COUNT_1_BYTE       0x3FF
 55 #define DMA_DESC_MAX_COUNT_2_BYTES      0x3FF
 56 #define DMA_DESC_MAX_COUNT_4_BYTES      0x7FF
 57 #define DMA_DESC_END_WITHOUT_IRQ        0x0
 58 #define DMA_DESC_END_WITH_IRQ           0x1
 59 #define DMA_DESC_FOLLOW_WITHOUT_IRQ     0x2
 60 #define DMA_DESC_FOLLOW_WITH_IRQ        0x3
 61 
 62 #define MAX_CHAN_NR                     12
 63 
 64 #define DMA_MASK_CTL0_MODE      0x33333333
 65 #define DMA_MASK_CTL2_MODE      0x00003333
 66 
 67 static unsigned int init_nr_desc_per_channel = 64;
 68 module_param(init_nr_desc_per_channel, uint, 0644);
 69 MODULE_PARM_DESC(init_nr_desc_per_channel,
 70                  "initial descriptors per channel (default: 64)");
 71 
 72 struct pch_dma_desc_regs {
 73         u32     dev_addr;
 74         u32     mem_addr;
 75         u32     size;
 76         u32     next;
 77 };
 78 
 79 struct pch_dma_regs {
 80         u32     dma_ctl0;
 81         u32     dma_ctl1;
 82         u32     dma_ctl2;
 83         u32     dma_ctl3;
 84         u32     dma_sts0;
 85         u32     dma_sts1;
 86         u32     dma_sts2;
 87         u32     reserved3;
 88         struct pch_dma_desc_regs desc[MAX_CHAN_NR];
 89 };
 90 
 91 struct pch_dma_desc {
 92         struct pch_dma_desc_regs regs;
 93         struct dma_async_tx_descriptor txd;
 94         struct list_head        desc_node;
 95         struct list_head        tx_list;
 96 };
 97 
 98 struct pch_dma_chan {
 99         struct dma_chan         chan;
100         void __iomem *membase;
101         enum dma_transfer_direction dir;
102         struct tasklet_struct   tasklet;
103         unsigned long           err_status;
104 
105         spinlock_t              lock;
106 
107         struct list_head        active_list;
108         struct list_head        queue;
109         struct list_head        free_list;
110         unsigned int            descs_allocated;
111 };
112 
113 #define PDC_DEV_ADDR    0x00
114 #define PDC_MEM_ADDR    0x04
115 #define PDC_SIZE        0x08
116 #define PDC_NEXT        0x0C
117 
118 #define channel_readl(pdc, name) \
119         readl((pdc)->membase + PDC_##name)
120 #define channel_writel(pdc, name, val) \
121         writel((val), (pdc)->membase + PDC_##name)
122 
123 struct pch_dma {
124         struct dma_device       dma;
125         void __iomem *membase;
126         struct pci_pool         *pool;
127         struct pch_dma_regs     regs;
128         struct pch_dma_desc_regs ch_regs[MAX_CHAN_NR];
129         struct pch_dma_chan     channels[MAX_CHAN_NR];
130 };
131 
132 #define PCH_DMA_CTL0    0x00
133 #define PCH_DMA_CTL1    0x04
134 #define PCH_DMA_CTL2    0x08
135 #define PCH_DMA_CTL3    0x0C
136 #define PCH_DMA_STS0    0x10
137 #define PCH_DMA_STS1    0x14
138 #define PCH_DMA_STS2    0x18
139 
140 #define dma_readl(pd, name) \
141         readl((pd)->membase + PCH_DMA_##name)
142 #define dma_writel(pd, name, val) \
143         writel((val), (pd)->membase + PCH_DMA_##name)
144 
145 static inline
146 struct pch_dma_desc *to_pd_desc(struct dma_async_tx_descriptor *txd)
147 {
148         return container_of(txd, struct pch_dma_desc, txd);
149 }
150 
151 static inline struct pch_dma_chan *to_pd_chan(struct dma_chan *chan)
152 {
153         return container_of(chan, struct pch_dma_chan, chan);
154 }
155 
156 static inline struct pch_dma *to_pd(struct dma_device *ddev)
157 {
158         return container_of(ddev, struct pch_dma, dma);
159 }
160 
161 static inline struct device *chan2dev(struct dma_chan *chan)
162 {
163         return &chan->dev->device;
164 }
165 
166 static inline struct device *chan2parent(struct dma_chan *chan)
167 {
168         return chan->dev->device.parent;
169 }
170 
171 static inline
172 struct pch_dma_desc *pdc_first_active(struct pch_dma_chan *pd_chan)
173 {
174         return list_first_entry(&pd_chan->active_list,
175                                 struct pch_dma_desc, desc_node);
176 }
177 
178 static inline
179 struct pch_dma_desc *pdc_first_queued(struct pch_dma_chan *pd_chan)
180 {
181         return list_first_entry(&pd_chan->queue,
182                                 struct pch_dma_desc, desc_node);
183 }
184 
185 static void pdc_enable_irq(struct dma_chan *chan, int enable)
186 {
187         struct pch_dma *pd = to_pd(chan->device);
188         u32 val;
189         int pos;
190 
191         if (chan->chan_id < 8)
192                 pos = chan->chan_id;
193         else
194                 pos = chan->chan_id + 8;
195 
196         val = dma_readl(pd, CTL2);
197 
198         if (enable)
199                 val |= 0x1 << pos;
200         else
201                 val &= ~(0x1 << pos);
202 
203         dma_writel(pd, CTL2, val);
204 
205         dev_dbg(chan2dev(chan), "pdc_enable_irq: chan %d -> %x\n",
206                 chan->chan_id, val);
207 }
208 
209 static void pdc_set_dir(struct dma_chan *chan)
210 {
211         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
212         struct pch_dma *pd = to_pd(chan->device);
213         u32 val;
214         u32 mask_mode;
215         u32 mask_ctl;
216 
217         if (chan->chan_id < 8) {
218                 val = dma_readl(pd, CTL0);
219 
220                 mask_mode = DMA_CTL0_MODE_MASK_BITS <<
221                                         (DMA_CTL0_BITS_PER_CH * chan->chan_id);
222                 mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
223                                        (DMA_CTL0_BITS_PER_CH * chan->chan_id));
224                 val &= mask_mode;
225                 if (pd_chan->dir == DMA_MEM_TO_DEV)
226                         val |= 0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
227                                        DMA_CTL0_DIR_SHIFT_BITS);
228                 else
229                         val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +
230                                          DMA_CTL0_DIR_SHIFT_BITS));
231 
232                 val |= mask_ctl;
233                 dma_writel(pd, CTL0, val);
234         } else {
235                 int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
236                 val = dma_readl(pd, CTL3);
237 
238                 mask_mode = DMA_CTL0_MODE_MASK_BITS <<
239                                                 (DMA_CTL0_BITS_PER_CH * ch);
240                 mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
241                                                  (DMA_CTL0_BITS_PER_CH * ch));
242                 val &= mask_mode;
243                 if (pd_chan->dir == DMA_MEM_TO_DEV)
244                         val |= 0x1 << (DMA_CTL0_BITS_PER_CH * ch +
245                                        DMA_CTL0_DIR_SHIFT_BITS);
246                 else
247                         val &= ~(0x1 << (DMA_CTL0_BITS_PER_CH * ch +
248                                          DMA_CTL0_DIR_SHIFT_BITS));
249                 val |= mask_ctl;
250                 dma_writel(pd, CTL3, val);
251         }
252 
253         dev_dbg(chan2dev(chan), "pdc_set_dir: chan %d -> %x\n",
254                 chan->chan_id, val);
255 }
256 
257 static void pdc_set_mode(struct dma_chan *chan, u32 mode)
258 {
259         struct pch_dma *pd = to_pd(chan->device);
260         u32 val;
261         u32 mask_ctl;
262         u32 mask_dir;
263 
264         if (chan->chan_id < 8) {
265                 mask_ctl = DMA_MASK_CTL0_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
266                            (DMA_CTL0_BITS_PER_CH * chan->chan_id));
267                 mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * chan->chan_id +\
268                                  DMA_CTL0_DIR_SHIFT_BITS);
269                 val = dma_readl(pd, CTL0);
270                 val &= mask_dir;
271                 val |= mode << (DMA_CTL0_BITS_PER_CH * chan->chan_id);
272                 val |= mask_ctl;
273                 dma_writel(pd, CTL0, val);
274         } else {
275                 int ch = chan->chan_id - 8; /* ch8-->0 ch9-->1 ... ch11->3 */
276                 mask_ctl = DMA_MASK_CTL2_MODE & ~(DMA_CTL0_MODE_MASK_BITS <<
277                                                  (DMA_CTL0_BITS_PER_CH * ch));
278                 mask_dir = 1 << (DMA_CTL0_BITS_PER_CH * ch +\
279                                  DMA_CTL0_DIR_SHIFT_BITS);
280                 val = dma_readl(pd, CTL3);
281                 val &= mask_dir;
282                 val |= mode << (DMA_CTL0_BITS_PER_CH * ch);
283                 val |= mask_ctl;
284                 dma_writel(pd, CTL3, val);
285         }
286 
287         dev_dbg(chan2dev(chan), "pdc_set_mode: chan %d -> %x\n",
288                 chan->chan_id, val);
289 }
290 
291 static u32 pdc_get_status0(struct pch_dma_chan *pd_chan)
292 {
293         struct pch_dma *pd = to_pd(pd_chan->chan.device);
294         u32 val;
295 
296         val = dma_readl(pd, STS0);
297         return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
298                         DMA_STATUS_BITS_PER_CH * pd_chan->chan.chan_id));
299 }
300 
301 static u32 pdc_get_status2(struct pch_dma_chan *pd_chan)
302 {
303         struct pch_dma *pd = to_pd(pd_chan->chan.device);
304         u32 val;
305 
306         val = dma_readl(pd, STS2);
307         return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
308                         DMA_STATUS_BITS_PER_CH * (pd_chan->chan.chan_id - 8)));
309 }
310 
311 static bool pdc_is_idle(struct pch_dma_chan *pd_chan)
312 {
313         u32 sts;
314 
315         if (pd_chan->chan.chan_id < 8)
316                 sts = pdc_get_status0(pd_chan);
317         else
318                 sts = pdc_get_status2(pd_chan);
319 
320 
321         if (sts == DMA_STATUS_IDLE)
322                 return true;
323         else
324                 return false;
325 }
326 
327 static void pdc_dostart(struct pch_dma_chan *pd_chan, struct pch_dma_desc* desc)
328 {
329         if (!pdc_is_idle(pd_chan)) {
330                 dev_err(chan2dev(&pd_chan->chan),
331                         "BUG: Attempt to start non-idle channel\n");
332                 return;
333         }
334 
335         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> dev_addr: %x\n",
336                 pd_chan->chan.chan_id, desc->regs.dev_addr);
337         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> mem_addr: %x\n",
338                 pd_chan->chan.chan_id, desc->regs.mem_addr);
339         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> size: %x\n",
340                 pd_chan->chan.chan_id, desc->regs.size);
341         dev_dbg(chan2dev(&pd_chan->chan), "chan %d -> next: %x\n",
342                 pd_chan->chan.chan_id, desc->regs.next);
343 
344         if (list_empty(&desc->tx_list)) {
345                 channel_writel(pd_chan, DEV_ADDR, desc->regs.dev_addr);
346                 channel_writel(pd_chan, MEM_ADDR, desc->regs.mem_addr);
347                 channel_writel(pd_chan, SIZE, desc->regs.size);
348                 channel_writel(pd_chan, NEXT, desc->regs.next);
349                 pdc_set_mode(&pd_chan->chan, DMA_CTL0_ONESHOT);
350         } else {
351                 channel_writel(pd_chan, NEXT, desc->txd.phys);
352                 pdc_set_mode(&pd_chan->chan, DMA_CTL0_SG);
353         }
354 }
355 
356 static void pdc_chain_complete(struct pch_dma_chan *pd_chan,
357                                struct pch_dma_desc *desc)
358 {
359         struct dma_async_tx_descriptor *txd = &desc->txd;
360         struct dmaengine_desc_callback cb;
361 
362         dmaengine_desc_get_callback(txd, &cb);
363         list_splice_init(&desc->tx_list, &pd_chan->free_list);
364         list_move(&desc->desc_node, &pd_chan->free_list);
365 
366         dmaengine_desc_callback_invoke(&cb, NULL);
367 }
368 
369 static void pdc_complete_all(struct pch_dma_chan *pd_chan)
370 {
371         struct pch_dma_desc *desc, *_d;
372         LIST_HEAD(list);
373 
374         BUG_ON(!pdc_is_idle(pd_chan));
375 
376         if (!list_empty(&pd_chan->queue))
377                 pdc_dostart(pd_chan, pdc_first_queued(pd_chan));
378 
379         list_splice_init(&pd_chan->active_list, &list);
380         list_splice_init(&pd_chan->queue, &pd_chan->active_list);
381 
382         list_for_each_entry_safe(desc, _d, &list, desc_node)
383                 pdc_chain_complete(pd_chan, desc);
384 }
385 
386 static void pdc_handle_error(struct pch_dma_chan *pd_chan)
387 {
388         struct pch_dma_desc *bad_desc;
389 
390         bad_desc = pdc_first_active(pd_chan);
391         list_del(&bad_desc->desc_node);
392 
393         list_splice_init(&pd_chan->queue, pd_chan->active_list.prev);
394 
395         if (!list_empty(&pd_chan->active_list))
396                 pdc_dostart(pd_chan, pdc_first_active(pd_chan));
397 
398         dev_crit(chan2dev(&pd_chan->chan), "Bad descriptor submitted\n");
399         dev_crit(chan2dev(&pd_chan->chan), "descriptor cookie: %d\n",
400                  bad_desc->txd.cookie);
401 
402         pdc_chain_complete(pd_chan, bad_desc);
403 }
404 
405 static void pdc_advance_work(struct pch_dma_chan *pd_chan)
406 {
407         if (list_empty(&pd_chan->active_list) ||
408                 list_is_singular(&pd_chan->active_list)) {
409                 pdc_complete_all(pd_chan);
410         } else {
411                 pdc_chain_complete(pd_chan, pdc_first_active(pd_chan));
412                 pdc_dostart(pd_chan, pdc_first_active(pd_chan));
413         }
414 }
415 
416 static dma_cookie_t pd_tx_submit(struct dma_async_tx_descriptor *txd)
417 {
418         struct pch_dma_desc *desc = to_pd_desc(txd);
419         struct pch_dma_chan *pd_chan = to_pd_chan(txd->chan);
420 
421         spin_lock(&pd_chan->lock);
422 
423         if (list_empty(&pd_chan->active_list)) {
424                 list_add_tail(&desc->desc_node, &pd_chan->active_list);
425                 pdc_dostart(pd_chan, desc);
426         } else {
427                 list_add_tail(&desc->desc_node, &pd_chan->queue);
428         }
429 
430         spin_unlock(&pd_chan->lock);
431         return 0;
432 }
433 
434 static struct pch_dma_desc *pdc_alloc_desc(struct dma_chan *chan, gfp_t flags)
435 {
436         struct pch_dma_desc *desc = NULL;
437         struct pch_dma *pd = to_pd(chan->device);
438         dma_addr_t addr;
439 
440         desc = pci_pool_zalloc(pd->pool, flags, &addr);
441         if (desc) {
442                 INIT_LIST_HEAD(&desc->tx_list);
443                 dma_async_tx_descriptor_init(&desc->txd, chan);
444                 desc->txd.tx_submit = pd_tx_submit;
445                 desc->txd.flags = DMA_CTRL_ACK;
446                 desc->txd.phys = addr;
447         }
448 
449         return desc;
450 }
451 
452 static struct pch_dma_desc *pdc_desc_get(struct pch_dma_chan *pd_chan)
453 {
454         struct pch_dma_desc *desc, *_d;
455         struct pch_dma_desc *ret = NULL;
456         int i = 0;
457 
458         spin_lock(&pd_chan->lock);
459         list_for_each_entry_safe(desc, _d, &pd_chan->free_list, desc_node) {
460                 i++;
461                 if (async_tx_test_ack(&desc->txd)) {
462                         list_del(&desc->desc_node);
463                         ret = desc;
464                         break;
465                 }
466                 dev_dbg(chan2dev(&pd_chan->chan), "desc %p not ACKed\n", desc);
467         }
468         spin_unlock(&pd_chan->lock);
469         dev_dbg(chan2dev(&pd_chan->chan), "scanned %d descriptors\n", i);
470 
471         if (!ret) {
472                 ret = pdc_alloc_desc(&pd_chan->chan, GFP_ATOMIC);
473                 if (ret) {
474                         spin_lock(&pd_chan->lock);
475                         pd_chan->descs_allocated++;
476                         spin_unlock(&pd_chan->lock);
477                 } else {
478                         dev_err(chan2dev(&pd_chan->chan),
479                                 "failed to alloc desc\n");
480                 }
481         }
482 
483         return ret;
484 }
485 
486 static void pdc_desc_put(struct pch_dma_chan *pd_chan,
487                          struct pch_dma_desc *desc)
488 {
489         if (desc) {
490                 spin_lock(&pd_chan->lock);
491                 list_splice_init(&desc->tx_list, &pd_chan->free_list);
492                 list_add(&desc->desc_node, &pd_chan->free_list);
493                 spin_unlock(&pd_chan->lock);
494         }
495 }
496 
497 static int pd_alloc_chan_resources(struct dma_chan *chan)
498 {
499         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
500         struct pch_dma_desc *desc;
501         LIST_HEAD(tmp_list);
502         int i;
503 
504         if (!pdc_is_idle(pd_chan)) {
505                 dev_dbg(chan2dev(chan), "DMA channel not idle ?\n");
506                 return -EIO;
507         }
508 
509         if (!list_empty(&pd_chan->free_list))
510                 return pd_chan->descs_allocated;
511 
512         for (i = 0; i < init_nr_desc_per_channel; i++) {
513                 desc = pdc_alloc_desc(chan, GFP_KERNEL);
514 
515                 if (!desc) {
516                         dev_warn(chan2dev(chan),
517                                 "Only allocated %d initial descriptors\n", i);
518                         break;
519                 }
520 
521                 list_add_tail(&desc->desc_node, &tmp_list);
522         }
523 
524         spin_lock_irq(&pd_chan->lock);
525         list_splice(&tmp_list, &pd_chan->free_list);
526         pd_chan->descs_allocated = i;
527         dma_cookie_init(chan);
528         spin_unlock_irq(&pd_chan->lock);
529 
530         pdc_enable_irq(chan, 1);
531 
532         return pd_chan->descs_allocated;
533 }
534 
535 static void pd_free_chan_resources(struct dma_chan *chan)
536 {
537         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
538         struct pch_dma *pd = to_pd(chan->device);
539         struct pch_dma_desc *desc, *_d;
540         LIST_HEAD(tmp_list);
541 
542         BUG_ON(!pdc_is_idle(pd_chan));
543         BUG_ON(!list_empty(&pd_chan->active_list));
544         BUG_ON(!list_empty(&pd_chan->queue));
545 
546         spin_lock_irq(&pd_chan->lock);
547         list_splice_init(&pd_chan->free_list, &tmp_list);
548         pd_chan->descs_allocated = 0;
549         spin_unlock_irq(&pd_chan->lock);
550 
551         list_for_each_entry_safe(desc, _d, &tmp_list, desc_node)
552                 pci_pool_free(pd->pool, desc, desc->txd.phys);
553 
554         pdc_enable_irq(chan, 0);
555 }
556 
557 static enum dma_status pd_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
558                                     struct dma_tx_state *txstate)
559 {
560         return dma_cookie_status(chan, cookie, txstate);
561 }
562 
563 static void pd_issue_pending(struct dma_chan *chan)
564 {
565         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
566 
567         if (pdc_is_idle(pd_chan)) {
568                 spin_lock(&pd_chan->lock);
569                 pdc_advance_work(pd_chan);
570                 spin_unlock(&pd_chan->lock);
571         }
572 }
573 
574 static struct dma_async_tx_descriptor *pd_prep_slave_sg(struct dma_chan *chan,
575                         struct scatterlist *sgl, unsigned int sg_len,
576                         enum dma_transfer_direction direction, unsigned long flags,
577                         void *context)
578 {
579         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
580         struct pch_dma_slave *pd_slave = chan->private;
581         struct pch_dma_desc *first = NULL;
582         struct pch_dma_desc *prev = NULL;
583         struct pch_dma_desc *desc = NULL;
584         struct scatterlist *sg;
585         dma_addr_t reg;
586         int i;
587 
588         if (unlikely(!sg_len)) {
589                 dev_info(chan2dev(chan), "prep_slave_sg: length is zero!\n");
590                 return NULL;
591         }
592 
593         if (direction == DMA_DEV_TO_MEM)
594                 reg = pd_slave->rx_reg;
595         else if (direction == DMA_MEM_TO_DEV)
596                 reg = pd_slave->tx_reg;
597         else
598                 return NULL;
599 
600         pd_chan->dir = direction;
601         pdc_set_dir(chan);
602 
603         for_each_sg(sgl, sg, sg_len, i) {
604                 desc = pdc_desc_get(pd_chan);
605 
606                 if (!desc)
607                         goto err_desc_get;
608 
609                 desc->regs.dev_addr = reg;
610                 desc->regs.mem_addr = sg_dma_address(sg);
611                 desc->regs.size = sg_dma_len(sg);
612                 desc->regs.next = DMA_DESC_FOLLOW_WITHOUT_IRQ;
613 
614                 switch (pd_slave->width) {
615                 case PCH_DMA_WIDTH_1_BYTE:
616                         if (desc->regs.size > DMA_DESC_MAX_COUNT_1_BYTE)
617                                 goto err_desc_get;
618                         desc->regs.size |= DMA_DESC_WIDTH_1_BYTE;
619                         break;
620                 case PCH_DMA_WIDTH_2_BYTES:
621                         if (desc->regs.size > DMA_DESC_MAX_COUNT_2_BYTES)
622                                 goto err_desc_get;
623                         desc->regs.size |= DMA_DESC_WIDTH_2_BYTES;
624                         break;
625                 case PCH_DMA_WIDTH_4_BYTES:
626                         if (desc->regs.size > DMA_DESC_MAX_COUNT_4_BYTES)
627                                 goto err_desc_get;
628                         desc->regs.size |= DMA_DESC_WIDTH_4_BYTES;
629                         break;
630                 default:
631                         goto err_desc_get;
632                 }
633 
634                 if (!first) {
635                         first = desc;
636                 } else {
637                         prev->regs.next |= desc->txd.phys;
638                         list_add_tail(&desc->desc_node, &first->tx_list);
639                 }
640 
641                 prev = desc;
642         }
643 
644         if (flags & DMA_PREP_INTERRUPT)
645                 desc->regs.next = DMA_DESC_END_WITH_IRQ;
646         else
647                 desc->regs.next = DMA_DESC_END_WITHOUT_IRQ;
648 
649         first->txd.cookie = -EBUSY;
650         desc->txd.flags = flags;
651 
652         return &first->txd;
653 
654 err_desc_get:
655         dev_err(chan2dev(chan), "failed to get desc or wrong parameters\n");
656         pdc_desc_put(pd_chan, first);
657         return NULL;
658 }
659 
660 static int pd_device_terminate_all(struct dma_chan *chan)
661 {
662         struct pch_dma_chan *pd_chan = to_pd_chan(chan);
663         struct pch_dma_desc *desc, *_d;
664         LIST_HEAD(list);
665 
666         spin_lock_irq(&pd_chan->lock);
667 
668         pdc_set_mode(&pd_chan->chan, DMA_CTL0_DISABLE);
669 
670         list_splice_init(&pd_chan->active_list, &list);
671         list_splice_init(&pd_chan->queue, &list);
672 
673         list_for_each_entry_safe(desc, _d, &list, desc_node)
674                 pdc_chain_complete(pd_chan, desc);
675 
676         spin_unlock_irq(&pd_chan->lock);
677 
678         return 0;
679 }
680 
681 static void pdc_tasklet(unsigned long data)
682 {
683         struct pch_dma_chan *pd_chan = (struct pch_dma_chan *)data;
684         unsigned long flags;
685 
686         if (!pdc_is_idle(pd_chan)) {
687                 dev_err(chan2dev(&pd_chan->chan),
688                         "BUG: handle non-idle channel in tasklet\n");
689                 return;
690         }
691 
692         spin_lock_irqsave(&pd_chan->lock, flags);
693         if (test_and_clear_bit(0, &pd_chan->err_status))
694                 pdc_handle_error(pd_chan);
695         else
696                 pdc_advance_work(pd_chan);
697         spin_unlock_irqrestore(&pd_chan->lock, flags);
698 }
699 
700 static irqreturn_t pd_irq(int irq, void *devid)
701 {
702         struct pch_dma *pd = (struct pch_dma *)devid;
703         struct pch_dma_chan *pd_chan;
704         u32 sts0;
705         u32 sts2;
706         int i;
707         int ret0 = IRQ_NONE;
708         int ret2 = IRQ_NONE;
709 
710         sts0 = dma_readl(pd, STS0);
711         sts2 = dma_readl(pd, STS2);
712 
713         dev_dbg(pd->dma.dev, "pd_irq sts0: %x\n", sts0);
714 
715         for (i = 0; i < pd->dma.chancnt; i++) {
716                 pd_chan = &pd->channels[i];
717 
718                 if (i < 8) {
719                         if (sts0 & DMA_STATUS_IRQ(i)) {
720                                 if (sts0 & DMA_STATUS0_ERR(i))
721                                         set_bit(0, &pd_chan->err_status);
722 
723                                 tasklet_schedule(&pd_chan->tasklet);
724                                 ret0 = IRQ_HANDLED;
725                         }
726                 } else {
727                         if (sts2 & DMA_STATUS_IRQ(i - 8)) {
728                                 if (sts2 & DMA_STATUS2_ERR(i))
729                                         set_bit(0, &pd_chan->err_status);
730 
731                                 tasklet_schedule(&pd_chan->tasklet);
732                                 ret2 = IRQ_HANDLED;
733                         }
734                 }
735         }
736 
737         /* clear interrupt bits in status register */
738         if (ret0)
739                 dma_writel(pd, STS0, sts0);
740         if (ret2)
741                 dma_writel(pd, STS2, sts2);
742 
743         return ret0 | ret2;
744 }
745 
746 #ifdef  CONFIG_PM
747 static void pch_dma_save_regs(struct pch_dma *pd)
748 {
749         struct pch_dma_chan *pd_chan;
750         struct dma_chan *chan, *_c;
751         int i = 0;
752 
753         pd->regs.dma_ctl0 = dma_readl(pd, CTL0);
754         pd->regs.dma_ctl1 = dma_readl(pd, CTL1);
755         pd->regs.dma_ctl2 = dma_readl(pd, CTL2);
756         pd->regs.dma_ctl3 = dma_readl(pd, CTL3);
757 
758         list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
759                 pd_chan = to_pd_chan(chan);
760 
761                 pd->ch_regs[i].dev_addr = channel_readl(pd_chan, DEV_ADDR);
762                 pd->ch_regs[i].mem_addr = channel_readl(pd_chan, MEM_ADDR);
763                 pd->ch_regs[i].size = channel_readl(pd_chan, SIZE);
764                 pd->ch_regs[i].next = channel_readl(pd_chan, NEXT);
765 
766                 i++;
767         }
768 }
769 
770 static void pch_dma_restore_regs(struct pch_dma *pd)
771 {
772         struct pch_dma_chan *pd_chan;
773         struct dma_chan *chan, *_c;
774         int i = 0;
775 
776         dma_writel(pd, CTL0, pd->regs.dma_ctl0);
777         dma_writel(pd, CTL1, pd->regs.dma_ctl1);
778         dma_writel(pd, CTL2, pd->regs.dma_ctl2);
779         dma_writel(pd, CTL3, pd->regs.dma_ctl3);
780 
781         list_for_each_entry_safe(chan, _c, &pd->dma.channels, device_node) {
782                 pd_chan = to_pd_chan(chan);
783 
784                 channel_writel(pd_chan, DEV_ADDR, pd->ch_regs[i].dev_addr);
785                 channel_writel(pd_chan, MEM_ADDR, pd->ch_regs[i].mem_addr);
786                 channel_writel(pd_chan, SIZE, pd->ch_regs[i].size);
787                 channel_writel(pd_chan, NEXT, pd->ch_regs[i].next);
788 
789                 i++;
790         }
791 }
792 
793 static int pch_dma_suspend(struct pci_dev *pdev, pm_message_t state)
794 {
795         struct pch_dma *pd = pci_get_drvdata(pdev);
796 
797         if (pd)
798                 pch_dma_save_regs(pd);
799 
800         pci_save_state(pdev);
801         pci_disable_device(pdev);
802         pci_set_power_state(pdev, pci_choose_state(pdev, state));
803 
804         return 0;
805 }
806 
807 static int pch_dma_resume(struct pci_dev *pdev)
808 {
809         struct pch_dma *pd = pci_get_drvdata(pdev);
810         int err;
811 
812         pci_set_power_state(pdev, PCI_D0);
813         pci_restore_state(pdev);
814 
815         err = pci_enable_device(pdev);
816         if (err) {
817                 dev_dbg(&pdev->dev, "failed to enable device\n");
818                 return err;
819         }
820 
821         if (pd)
822                 pch_dma_restore_regs(pd);
823 
824         return 0;
825 }
826 #endif
827 
828 static int pch_dma_probe(struct pci_dev *pdev,
829                                    const struct pci_device_id *id)
830 {
831         struct pch_dma *pd;
832         struct pch_dma_regs *regs;
833         unsigned int nr_channels;
834         int err;
835         int i;
836 
837         nr_channels = id->driver_data;
838         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
839         if (!pd)
840                 return -ENOMEM;
841 
842         pci_set_drvdata(pdev, pd);
843 
844         err = pci_enable_device(pdev);
845         if (err) {
846                 dev_err(&pdev->dev, "Cannot enable PCI device\n");
847                 goto err_free_mem;
848         }
849 
850         if (!(pci_resource_flags(pdev, 1) & IORESOURCE_MEM)) {
851                 dev_err(&pdev->dev, "Cannot find proper base address\n");
852                 err = -ENODEV;
853                 goto err_disable_pdev;
854         }
855 
856         err = pci_request_regions(pdev, DRV_NAME);
857         if (err) {
858                 dev_err(&pdev->dev, "Cannot obtain PCI resources\n");
859                 goto err_disable_pdev;
860         }
861 
862         err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
863         if (err) {
864                 dev_err(&pdev->dev, "Cannot set proper DMA config\n");
865                 goto err_free_res;
866         }
867 
868         regs = pd->membase = pci_iomap(pdev, 1, 0);
869         if (!pd->membase) {
870                 dev_err(&pdev->dev, "Cannot map MMIO registers\n");
871                 err = -ENOMEM;
872                 goto err_free_res;
873         }
874 
875         pci_set_master(pdev);
876 
877         err = request_irq(pdev->irq, pd_irq, IRQF_SHARED, DRV_NAME, pd);
878         if (err) {
879                 dev_err(&pdev->dev, "Failed to request IRQ\n");
880                 goto err_iounmap;
881         }
882 
883         pd->pool = pci_pool_create("pch_dma_desc_pool", pdev,
884                                    sizeof(struct pch_dma_desc), 4, 0);
885         if (!pd->pool) {
886                 dev_err(&pdev->dev, "Failed to alloc DMA descriptors\n");
887                 err = -ENOMEM;
888                 goto err_free_irq;
889         }
890 
891         pd->dma.dev = &pdev->dev;
892 
893         INIT_LIST_HEAD(&pd->dma.channels);
894 
895         for (i = 0; i < nr_channels; i++) {
896                 struct pch_dma_chan *pd_chan = &pd->channels[i];
897 
898                 pd_chan->chan.device = &pd->dma;
899                 dma_cookie_init(&pd_chan->chan);
900 
901                 pd_chan->membase = &regs->desc[i];
902 
903                 spin_lock_init(&pd_chan->lock);
904 
905                 INIT_LIST_HEAD(&pd_chan->active_list);
906                 INIT_LIST_HEAD(&pd_chan->queue);
907                 INIT_LIST_HEAD(&pd_chan->free_list);
908 
909                 tasklet_init(&pd_chan->tasklet, pdc_tasklet,
910                              (unsigned long)pd_chan);
911                 list_add_tail(&pd_chan->chan.device_node, &pd->dma.channels);
912         }
913 
914         dma_cap_zero(pd->dma.cap_mask);
915         dma_cap_set(DMA_PRIVATE, pd->dma.cap_mask);
916         dma_cap_set(DMA_SLAVE, pd->dma.cap_mask);
917 
918         pd->dma.device_alloc_chan_resources = pd_alloc_chan_resources;
919         pd->dma.device_free_chan_resources = pd_free_chan_resources;
920         pd->dma.device_tx_status = pd_tx_status;
921         pd->dma.device_issue_pending = pd_issue_pending;
922         pd->dma.device_prep_slave_sg = pd_prep_slave_sg;
923         pd->dma.device_terminate_all = pd_device_terminate_all;
924 
925         err = dma_async_device_register(&pd->dma);
926         if (err) {
927                 dev_err(&pdev->dev, "Failed to register DMA device\n");
928                 goto err_free_pool;
929         }
930 
931         return 0;
932 
933 err_free_pool:
934         pci_pool_destroy(pd->pool);
935 err_free_irq:
936         free_irq(pdev->irq, pd);
937 err_iounmap:
938         pci_iounmap(pdev, pd->membase);
939 err_free_res:
940         pci_release_regions(pdev);
941 err_disable_pdev:
942         pci_disable_device(pdev);
943 err_free_mem:
944         kfree(pd);
945         return err;
946 }
947 
948 static void pch_dma_remove(struct pci_dev *pdev)
949 {
950         struct pch_dma *pd = pci_get_drvdata(pdev);
951         struct pch_dma_chan *pd_chan;
952         struct dma_chan *chan, *_c;
953 
954         if (pd) {
955                 dma_async_device_unregister(&pd->dma);
956 
957                 free_irq(pdev->irq, pd);
958 
959                 list_for_each_entry_safe(chan, _c, &pd->dma.channels,
960                                          device_node) {
961                         pd_chan = to_pd_chan(chan);
962 
963                         tasklet_kill(&pd_chan->tasklet);
964                 }
965 
966                 pci_pool_destroy(pd->pool);
967                 pci_iounmap(pdev, pd->membase);
968                 pci_release_regions(pdev);
969                 pci_disable_device(pdev);
970                 kfree(pd);
971         }
972 }
973 
974 /* PCI Device ID of DMA device */
975 #define PCI_VENDOR_ID_ROHM             0x10DB
976 #define PCI_DEVICE_ID_EG20T_PCH_DMA_8CH        0x8810
977 #define PCI_DEVICE_ID_EG20T_PCH_DMA_4CH        0x8815
978 #define PCI_DEVICE_ID_ML7213_DMA1_8CH   0x8026
979 #define PCI_DEVICE_ID_ML7213_DMA2_8CH   0x802B
980 #define PCI_DEVICE_ID_ML7213_DMA3_4CH   0x8034
981 #define PCI_DEVICE_ID_ML7213_DMA4_12CH  0x8032
982 #define PCI_DEVICE_ID_ML7223_DMA1_4CH   0x800B
983 #define PCI_DEVICE_ID_ML7223_DMA2_4CH   0x800E
984 #define PCI_DEVICE_ID_ML7223_DMA3_4CH   0x8017
985 #define PCI_DEVICE_ID_ML7223_DMA4_4CH   0x803B
986 #define PCI_DEVICE_ID_ML7831_DMA1_8CH   0x8810
987 #define PCI_DEVICE_ID_ML7831_DMA2_4CH   0x8815
988 
989 static const struct pci_device_id pch_dma_id_table[] = {
990         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_8CH), 8 },
991         { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_EG20T_PCH_DMA_4CH), 4 },
992         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA1_8CH), 8}, /* UART Video */
993         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA2_8CH), 8}, /* PCMIF SPI */
994         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA3_4CH), 4}, /* FPGA */
995         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7213_DMA4_12CH), 12}, /* I2S */
996         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA1_4CH), 4}, /* UART */
997         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA2_4CH), 4}, /* Video SPI */
998         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA3_4CH), 4}, /* Security */
999         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7223_DMA4_4CH), 4}, /* FPGA */
1000         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA1_8CH), 8}, /* UART */
1001         { PCI_VDEVICE(ROHM, PCI_DEVICE_ID_ML7831_DMA2_4CH), 4}, /* SPI */
1002         { 0, },
1003 };
1004 
1005 static struct pci_driver pch_dma_driver = {
1006         .name           = DRV_NAME,
1007         .id_table       = pch_dma_id_table,
1008         .probe          = pch_dma_probe,
1009         .remove         = pch_dma_remove,
1010 #ifdef CONFIG_PM
1011         .suspend        = pch_dma_suspend,
1012         .resume         = pch_dma_resume,
1013 #endif
1014 };
1015 
1016 module_pci_driver(pch_dma_driver);
1017 
1018 MODULE_DESCRIPTION("Intel EG20T PCH / LAPIS Semicon ML7213/ML7223/ML7831 IOH "
1019                    "DMA controller driver");
1020 MODULE_AUTHOR("Yong Wang <yong.y.wang@intel.com>");
1021 MODULE_LICENSE("GPL v2");
1022 MODULE_DEVICE_TABLE(pci, pch_dma_id_table);
1023 

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