1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2019 Linaro Ltd.
4 // Copyright (C) 2019 Socionext Inc.
5
6 #include <linux/bits.h>
7 #include <linux/clk.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/interrupt.h>
10 #include <linux/iopoll.h>
11 #include <linux/list.h>
12 #include <linux/module.h>
13 #include <linux/of_dma.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/types.h>
17 #include <linux/bitfield.h>
18
19 #include "virt-dma.h"
20
21 #define MLB_HDMAC_DMACR 0x0 /* global */
22 #define MLB_HDMAC_DE BIT(31)
23 #define MLB_HDMAC_DS BIT(30)
24 #define MLB_HDMAC_PR BIT(28)
25 #define MLB_HDMAC_DH GENMASK(27, 24)
26
27 #define MLB_HDMAC_CH_STRIDE 0x10
28
29 #define MLB_HDMAC_DMACA 0x0 /* channel */
30 #define MLB_HDMAC_EB BIT(31)
31 #define MLB_HDMAC_PB BIT(30)
32 #define MLB_HDMAC_ST BIT(29)
33 #define MLB_HDMAC_IS GENMASK(28, 24)
34 #define MLB_HDMAC_BT GENMASK(23, 20)
35 #define MLB_HDMAC_BC GENMASK(19, 16)
36 #define MLB_HDMAC_TC GENMASK(15, 0)
37 #define MLB_HDMAC_DMACB 0x4
38 #define MLB_HDMAC_TT GENMASK(31, 30)
39 #define MLB_HDMAC_MS GENMASK(29, 28)
40 #define MLB_HDMAC_TW GENMASK(27, 26)
41 #define MLB_HDMAC_FS BIT(25)
42 #define MLB_HDMAC_FD BIT(24)
43 #define MLB_HDMAC_RC BIT(23)
44 #define MLB_HDMAC_RS BIT(22)
45 #define MLB_HDMAC_RD BIT(21)
46 #define MLB_HDMAC_EI BIT(20)
47 #define MLB_HDMAC_CI BIT(19)
48 #define HDMAC_PAUSE 0x7
49 #define MLB_HDMAC_SS GENMASK(18, 16)
50 #define MLB_HDMAC_SP GENMASK(15, 12)
51 #define MLB_HDMAC_DP GENMASK(11, 8)
52 #define MLB_HDMAC_DMACSA 0x8
53 #define MLB_HDMAC_DMACDA 0xc
54
55 #define MLB_HDMAC_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
56 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
57 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
58
59 struct milbeaut_hdmac_desc {
60 struct virt_dma_desc vd;
61 struct scatterlist *sgl;
62 unsigned int sg_len;
63 unsigned int sg_cur;
64 enum dma_transfer_direction dir;
65 };
66
67 struct milbeaut_hdmac_chan {
68 struct virt_dma_chan vc;
69 struct milbeaut_hdmac_device *mdev;
70 struct milbeaut_hdmac_desc *md;
71 void __iomem *reg_ch_base;
72 unsigned int slave_id;
73 struct dma_slave_config cfg;
74 };
75
76 struct milbeaut_hdmac_device {
77 struct dma_device ddev;
78 struct clk *clk;
79 void __iomem *reg_base;
80 struct milbeaut_hdmac_chan channels[];
81 };
82
83 static struct milbeaut_hdmac_chan *
to_milbeaut_hdmac_chan(struct virt_dma_chan * vc)84 to_milbeaut_hdmac_chan(struct virt_dma_chan *vc)
85 {
86 return container_of(vc, struct milbeaut_hdmac_chan, vc);
87 }
88
89 static struct milbeaut_hdmac_desc *
to_milbeaut_hdmac_desc(struct virt_dma_desc * vd)90 to_milbeaut_hdmac_desc(struct virt_dma_desc *vd)
91 {
92 return container_of(vd, struct milbeaut_hdmac_desc, vd);
93 }
94
95 /* mc->vc.lock must be held by caller */
96 static struct milbeaut_hdmac_desc *
milbeaut_hdmac_next_desc(struct milbeaut_hdmac_chan * mc)97 milbeaut_hdmac_next_desc(struct milbeaut_hdmac_chan *mc)
98 {
99 struct virt_dma_desc *vd;
100
101 vd = vchan_next_desc(&mc->vc);
102 if (!vd) {
103 mc->md = NULL;
104 return NULL;
105 }
106
107 list_del(&vd->node);
108
109 mc->md = to_milbeaut_hdmac_desc(vd);
110
111 return mc->md;
112 }
113
114 /* mc->vc.lock must be held by caller */
milbeaut_chan_start(struct milbeaut_hdmac_chan * mc,struct milbeaut_hdmac_desc * md)115 static void milbeaut_chan_start(struct milbeaut_hdmac_chan *mc,
116 struct milbeaut_hdmac_desc *md)
117 {
118 struct scatterlist *sg;
119 u32 cb, ca, src_addr, dest_addr, len;
120 u32 width, burst;
121
122 sg = &md->sgl[md->sg_cur];
123 len = sg_dma_len(sg);
124
125 cb = MLB_HDMAC_CI | MLB_HDMAC_EI;
126 if (md->dir == DMA_MEM_TO_DEV) {
127 cb |= MLB_HDMAC_FD;
128 width = mc->cfg.dst_addr_width;
129 burst = mc->cfg.dst_maxburst;
130 src_addr = sg_dma_address(sg);
131 dest_addr = mc->cfg.dst_addr;
132 } else {
133 cb |= MLB_HDMAC_FS;
134 width = mc->cfg.src_addr_width;
135 burst = mc->cfg.src_maxburst;
136 src_addr = mc->cfg.src_addr;
137 dest_addr = sg_dma_address(sg);
138 }
139 cb |= FIELD_PREP(MLB_HDMAC_TW, (width >> 1));
140 cb |= FIELD_PREP(MLB_HDMAC_MS, 2);
141
142 writel_relaxed(MLB_HDMAC_DE, mc->mdev->reg_base + MLB_HDMAC_DMACR);
143 writel_relaxed(src_addr, mc->reg_ch_base + MLB_HDMAC_DMACSA);
144 writel_relaxed(dest_addr, mc->reg_ch_base + MLB_HDMAC_DMACDA);
145 writel_relaxed(cb, mc->reg_ch_base + MLB_HDMAC_DMACB);
146
147 ca = FIELD_PREP(MLB_HDMAC_IS, mc->slave_id);
148 if (burst == 16)
149 ca |= FIELD_PREP(MLB_HDMAC_BT, 0xf);
150 else if (burst == 8)
151 ca |= FIELD_PREP(MLB_HDMAC_BT, 0xd);
152 else if (burst == 4)
153 ca |= FIELD_PREP(MLB_HDMAC_BT, 0xb);
154 burst *= width;
155 ca |= FIELD_PREP(MLB_HDMAC_TC, (len / burst - 1));
156 writel_relaxed(ca, mc->reg_ch_base + MLB_HDMAC_DMACA);
157 ca |= MLB_HDMAC_EB;
158 writel_relaxed(ca, mc->reg_ch_base + MLB_HDMAC_DMACA);
159 }
160
161 /* mc->vc.lock must be held by caller */
milbeaut_hdmac_start(struct milbeaut_hdmac_chan * mc)162 static void milbeaut_hdmac_start(struct milbeaut_hdmac_chan *mc)
163 {
164 struct milbeaut_hdmac_desc *md;
165
166 md = milbeaut_hdmac_next_desc(mc);
167 if (md)
168 milbeaut_chan_start(mc, md);
169 }
170
milbeaut_hdmac_interrupt(int irq,void * dev_id)171 static irqreturn_t milbeaut_hdmac_interrupt(int irq, void *dev_id)
172 {
173 struct milbeaut_hdmac_chan *mc = dev_id;
174 struct milbeaut_hdmac_desc *md;
175 u32 val;
176
177 spin_lock(&mc->vc.lock);
178
179 /* Ack and Disable irqs */
180 val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACB);
181 val &= ~(FIELD_PREP(MLB_HDMAC_SS, HDMAC_PAUSE));
182 writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACB);
183 val &= ~MLB_HDMAC_EI;
184 val &= ~MLB_HDMAC_CI;
185 writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACB);
186
187 md = mc->md;
188 if (!md)
189 goto out;
190
191 md->sg_cur++;
192
193 if (md->sg_cur >= md->sg_len) {
194 vchan_cookie_complete(&md->vd);
195 md = milbeaut_hdmac_next_desc(mc);
196 if (!md)
197 goto out;
198 }
199
200 milbeaut_chan_start(mc, md);
201
202 out:
203 spin_unlock(&mc->vc.lock);
204 return IRQ_HANDLED;
205 }
206
milbeaut_hdmac_free_chan_resources(struct dma_chan * chan)207 static void milbeaut_hdmac_free_chan_resources(struct dma_chan *chan)
208 {
209 vchan_free_chan_resources(to_virt_chan(chan));
210 }
211
212 static int
milbeaut_hdmac_chan_config(struct dma_chan * chan,struct dma_slave_config * cfg)213 milbeaut_hdmac_chan_config(struct dma_chan *chan, struct dma_slave_config *cfg)
214 {
215 struct virt_dma_chan *vc = to_virt_chan(chan);
216 struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
217
218 spin_lock(&mc->vc.lock);
219 mc->cfg = *cfg;
220 spin_unlock(&mc->vc.lock);
221
222 return 0;
223 }
224
milbeaut_hdmac_chan_pause(struct dma_chan * chan)225 static int milbeaut_hdmac_chan_pause(struct dma_chan *chan)
226 {
227 struct virt_dma_chan *vc = to_virt_chan(chan);
228 struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
229 u32 val;
230
231 spin_lock(&mc->vc.lock);
232 val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
233 val |= MLB_HDMAC_PB;
234 writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
235 spin_unlock(&mc->vc.lock);
236
237 return 0;
238 }
239
milbeaut_hdmac_chan_resume(struct dma_chan * chan)240 static int milbeaut_hdmac_chan_resume(struct dma_chan *chan)
241 {
242 struct virt_dma_chan *vc = to_virt_chan(chan);
243 struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
244 u32 val;
245
246 spin_lock(&mc->vc.lock);
247 val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
248 val &= ~MLB_HDMAC_PB;
249 writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
250 spin_unlock(&mc->vc.lock);
251
252 return 0;
253 }
254
255 static struct dma_async_tx_descriptor *
milbeaut_hdmac_prep_slave_sg(struct dma_chan * chan,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction direction,unsigned long flags,void * context)256 milbeaut_hdmac_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
257 unsigned int sg_len,
258 enum dma_transfer_direction direction,
259 unsigned long flags, void *context)
260 {
261 struct virt_dma_chan *vc = to_virt_chan(chan);
262 struct milbeaut_hdmac_desc *md;
263 int i;
264
265 if (!is_slave_direction(direction))
266 return NULL;
267
268 md = kzalloc(sizeof(*md), GFP_NOWAIT);
269 if (!md)
270 return NULL;
271
272 md->sgl = kzalloc(sizeof(*sgl) * sg_len, GFP_NOWAIT);
273 if (!md->sgl) {
274 kfree(md);
275 return NULL;
276 }
277
278 for (i = 0; i < sg_len; i++)
279 md->sgl[i] = sgl[i];
280
281 md->sg_len = sg_len;
282 md->dir = direction;
283
284 return vchan_tx_prep(vc, &md->vd, flags);
285 }
286
milbeaut_hdmac_terminate_all(struct dma_chan * chan)287 static int milbeaut_hdmac_terminate_all(struct dma_chan *chan)
288 {
289 struct virt_dma_chan *vc = to_virt_chan(chan);
290 struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
291 unsigned long flags;
292 u32 val;
293
294 LIST_HEAD(head);
295
296 spin_lock_irqsave(&vc->lock, flags);
297
298 val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA);
299 val &= ~MLB_HDMAC_EB; /* disable the channel */
300 writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA);
301
302 if (mc->md) {
303 vchan_terminate_vdesc(&mc->md->vd);
304 mc->md = NULL;
305 }
306
307 vchan_get_all_descriptors(vc, &head);
308
309 spin_unlock_irqrestore(&vc->lock, flags);
310
311 vchan_dma_desc_free_list(vc, &head);
312
313 return 0;
314 }
315
milbeaut_hdmac_synchronize(struct dma_chan * chan)316 static void milbeaut_hdmac_synchronize(struct dma_chan *chan)
317 {
318 vchan_synchronize(to_virt_chan(chan));
319 }
320
milbeaut_hdmac_tx_status(struct dma_chan * chan,dma_cookie_t cookie,struct dma_tx_state * txstate)321 static enum dma_status milbeaut_hdmac_tx_status(struct dma_chan *chan,
322 dma_cookie_t cookie,
323 struct dma_tx_state *txstate)
324 {
325 struct virt_dma_chan *vc;
326 struct virt_dma_desc *vd;
327 struct milbeaut_hdmac_chan *mc;
328 struct milbeaut_hdmac_desc *md = NULL;
329 enum dma_status stat;
330 unsigned long flags;
331 int i;
332
333 stat = dma_cookie_status(chan, cookie, txstate);
334 /* Return immediately if we do not need to compute the residue. */
335 if (stat == DMA_COMPLETE || !txstate)
336 return stat;
337
338 vc = to_virt_chan(chan);
339
340 spin_lock_irqsave(&vc->lock, flags);
341
342 mc = to_milbeaut_hdmac_chan(vc);
343
344 /* residue from the on-flight chunk */
345 if (mc->md && mc->md->vd.tx.cookie == cookie) {
346 struct scatterlist *sg;
347 u32 done;
348
349 md = mc->md;
350 sg = &md->sgl[md->sg_cur];
351
352 if (md->dir == DMA_DEV_TO_MEM)
353 done = readl_relaxed(mc->reg_ch_base
354 + MLB_HDMAC_DMACDA);
355 else
356 done = readl_relaxed(mc->reg_ch_base
357 + MLB_HDMAC_DMACSA);
358 done -= sg_dma_address(sg);
359
360 txstate->residue = -done;
361 }
362
363 if (!md) {
364 vd = vchan_find_desc(vc, cookie);
365 if (vd)
366 md = to_milbeaut_hdmac_desc(vd);
367 }
368
369 if (md) {
370 /* residue from the queued chunks */
371 for (i = md->sg_cur; i < md->sg_len; i++)
372 txstate->residue += sg_dma_len(&md->sgl[i]);
373 }
374
375 spin_unlock_irqrestore(&vc->lock, flags);
376
377 return stat;
378 }
379
milbeaut_hdmac_issue_pending(struct dma_chan * chan)380 static void milbeaut_hdmac_issue_pending(struct dma_chan *chan)
381 {
382 struct virt_dma_chan *vc = to_virt_chan(chan);
383 struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc);
384 unsigned long flags;
385
386 spin_lock_irqsave(&vc->lock, flags);
387
388 if (vchan_issue_pending(vc) && !mc->md)
389 milbeaut_hdmac_start(mc);
390
391 spin_unlock_irqrestore(&vc->lock, flags);
392 }
393
milbeaut_hdmac_desc_free(struct virt_dma_desc * vd)394 static void milbeaut_hdmac_desc_free(struct virt_dma_desc *vd)
395 {
396 struct milbeaut_hdmac_desc *md = to_milbeaut_hdmac_desc(vd);
397
398 kfree(md->sgl);
399 kfree(md);
400 }
401
402 static struct dma_chan *
milbeaut_hdmac_xlate(struct of_phandle_args * dma_spec,struct of_dma * of_dma)403 milbeaut_hdmac_xlate(struct of_phandle_args *dma_spec, struct of_dma *of_dma)
404 {
405 struct milbeaut_hdmac_device *mdev = of_dma->of_dma_data;
406 struct milbeaut_hdmac_chan *mc;
407 struct virt_dma_chan *vc;
408 struct dma_chan *chan;
409
410 if (dma_spec->args_count != 1)
411 return NULL;
412
413 chan = dma_get_any_slave_channel(&mdev->ddev);
414 if (!chan)
415 return NULL;
416
417 vc = to_virt_chan(chan);
418 mc = to_milbeaut_hdmac_chan(vc);
419 mc->slave_id = dma_spec->args[0];
420
421 return chan;
422 }
423
milbeaut_hdmac_chan_init(struct platform_device * pdev,struct milbeaut_hdmac_device * mdev,int chan_id)424 static int milbeaut_hdmac_chan_init(struct platform_device *pdev,
425 struct milbeaut_hdmac_device *mdev,
426 int chan_id)
427 {
428 struct device *dev = &pdev->dev;
429 struct milbeaut_hdmac_chan *mc = &mdev->channels[chan_id];
430 char *irq_name;
431 int irq, ret;
432
433 irq = platform_get_irq(pdev, chan_id);
434 if (irq < 0)
435 return irq;
436
437 irq_name = devm_kasprintf(dev, GFP_KERNEL, "milbeaut-hdmac-%d",
438 chan_id);
439 if (!irq_name)
440 return -ENOMEM;
441
442 ret = devm_request_irq(dev, irq, milbeaut_hdmac_interrupt,
443 IRQF_SHARED, irq_name, mc);
444 if (ret)
445 return ret;
446
447 mc->mdev = mdev;
448 mc->reg_ch_base = mdev->reg_base + MLB_HDMAC_CH_STRIDE * (chan_id + 1);
449 mc->vc.desc_free = milbeaut_hdmac_desc_free;
450 vchan_init(&mc->vc, &mdev->ddev);
451
452 return 0;
453 }
454
milbeaut_hdmac_probe(struct platform_device * pdev)455 static int milbeaut_hdmac_probe(struct platform_device *pdev)
456 {
457 struct device *dev = &pdev->dev;
458 struct milbeaut_hdmac_device *mdev;
459 struct dma_device *ddev;
460 int nr_chans, ret, i;
461
462 nr_chans = platform_irq_count(pdev);
463 if (nr_chans < 0)
464 return nr_chans;
465
466 ret = dma_set_mask(dev, DMA_BIT_MASK(32));
467 if (ret)
468 return ret;
469
470 mdev = devm_kzalloc(dev, struct_size(mdev, channels, nr_chans),
471 GFP_KERNEL);
472 if (!mdev)
473 return -ENOMEM;
474
475 mdev->reg_base = devm_platform_ioremap_resource(pdev, 0);
476 if (IS_ERR(mdev->reg_base))
477 return PTR_ERR(mdev->reg_base);
478
479 mdev->clk = devm_clk_get(dev, NULL);
480 if (IS_ERR(mdev->clk)) {
481 dev_err(dev, "failed to get clock\n");
482 return PTR_ERR(mdev->clk);
483 }
484
485 ret = clk_prepare_enable(mdev->clk);
486 if (ret)
487 return ret;
488
489 ddev = &mdev->ddev;
490 ddev->dev = dev;
491 dma_cap_set(DMA_SLAVE, ddev->cap_mask);
492 dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
493 ddev->src_addr_widths = MLB_HDMAC_BUSWIDTHS;
494 ddev->dst_addr_widths = MLB_HDMAC_BUSWIDTHS;
495 ddev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM);
496 ddev->device_free_chan_resources = milbeaut_hdmac_free_chan_resources;
497 ddev->device_config = milbeaut_hdmac_chan_config;
498 ddev->device_pause = milbeaut_hdmac_chan_pause;
499 ddev->device_resume = milbeaut_hdmac_chan_resume;
500 ddev->device_prep_slave_sg = milbeaut_hdmac_prep_slave_sg;
501 ddev->device_terminate_all = milbeaut_hdmac_terminate_all;
502 ddev->device_synchronize = milbeaut_hdmac_synchronize;
503 ddev->device_tx_status = milbeaut_hdmac_tx_status;
504 ddev->device_issue_pending = milbeaut_hdmac_issue_pending;
505 INIT_LIST_HEAD(&ddev->channels);
506
507 for (i = 0; i < nr_chans; i++) {
508 ret = milbeaut_hdmac_chan_init(pdev, mdev, i);
509 if (ret)
510 goto disable_clk;
511 }
512
513 ret = dma_async_device_register(ddev);
514 if (ret)
515 goto disable_clk;
516
517 ret = of_dma_controller_register(dev->of_node,
518 milbeaut_hdmac_xlate, mdev);
519 if (ret)
520 goto unregister_dmac;
521
522 platform_set_drvdata(pdev, mdev);
523
524 return 0;
525
526 unregister_dmac:
527 dma_async_device_unregister(ddev);
528 disable_clk:
529 clk_disable_unprepare(mdev->clk);
530
531 return ret;
532 }
533
milbeaut_hdmac_remove(struct platform_device * pdev)534 static int milbeaut_hdmac_remove(struct platform_device *pdev)
535 {
536 struct milbeaut_hdmac_device *mdev = platform_get_drvdata(pdev);
537 struct dma_chan *chan;
538 int ret;
539
540 /*
541 * Before reaching here, almost all descriptors have been freed by the
542 * ->device_free_chan_resources() hook. However, each channel might
543 * be still holding one descriptor that was on-flight at that moment.
544 * Terminate it to make sure this hardware is no longer running. Then,
545 * free the channel resources once again to avoid memory leak.
546 */
547 list_for_each_entry(chan, &mdev->ddev.channels, device_node) {
548 ret = dmaengine_terminate_sync(chan);
549 if (ret)
550 return ret;
551 milbeaut_hdmac_free_chan_resources(chan);
552 }
553
554 of_dma_controller_free(pdev->dev.of_node);
555 dma_async_device_unregister(&mdev->ddev);
556 clk_disable_unprepare(mdev->clk);
557
558 return 0;
559 }
560
561 static const struct of_device_id milbeaut_hdmac_match[] = {
562 { .compatible = "socionext,milbeaut-m10v-hdmac" },
563 { /* sentinel */ }
564 };
565 MODULE_DEVICE_TABLE(of, milbeaut_hdmac_match);
566
567 static struct platform_driver milbeaut_hdmac_driver = {
568 .probe = milbeaut_hdmac_probe,
569 .remove = milbeaut_hdmac_remove,
570 .driver = {
571 .name = "milbeaut-m10v-hdmac",
572 .of_match_table = milbeaut_hdmac_match,
573 },
574 };
575 module_platform_driver(milbeaut_hdmac_driver);
576
577 MODULE_DESCRIPTION("Milbeaut HDMAC DmaEngine driver");
578 MODULE_LICENSE("GPL v2");
579