xref: /linux/drivers/dma/loongson/loongson2-apb-cmc-dma.c (revision 0fc8f6200d2313278fbf4539bbab74677c685531)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Loongson-2 Chain Multi-Channel DMA Controller driver
4  *
5  * Copyright (C) 2024-2026 Loongson Technology Corporation Limited
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/acpi_dma.h>
10 #include <linux/bitfield.h>
11 #include <linux/clk.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/dmapool.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_dma.h>
19 #include <linux/platform_device.h>
20 #include <linux/slab.h>
21 
22 #include "../dmaengine.h"
23 #include "../virt-dma.h"
24 
25 #define LOONGSON2_CMCDMA_ISR		0x0	/* DMA Interrupt Status Register */
26 #define LOONGSON2_CMCDMA_IFCR		0x4	/* DMA Interrupt Flag Clear Register */
27 #define LOONGSON2_CMCDMA_CCR		0x8	/* DMA Channel Configuration Register */
28 #define LOONGSON2_CMCDMA_CNDTR		0xc	/* DMA Channel Transmit Count Register */
29 #define LOONGSON2_CMCDMA_CPAR		0x10	/* DMA Channel Peripheral Address Register */
30 #define LOONGSON2_CMCDMA_CMAR		0x14	/* DMA Channel Memory Address Register */
31 
32 /* Bitfields of DMA interrupt status register */
33 #define LOONGSON2_CMCDMA_TCI		BIT(1) /* Transfer Complete Interrupt */
34 #define LOONGSON2_CMCDMA_HTI		BIT(2) /* Half Transfer Interrupt */
35 #define LOONGSON2_CMCDMA_TEI		BIT(3) /* Transfer Error Interrupt */
36 
37 #define LOONGSON2_CMCDMA_MASKI		\
38 	(LOONGSON2_CMCDMA_TCI | LOONGSON2_CMCDMA_HTI | LOONGSON2_CMCDMA_TEI)
39 
40 /* Bitfields of DMA channel x Configuration Register */
41 #define LOONGSON2_CMCDMA_CCR_EN		BIT(0) /* Stream Enable */
42 #define LOONGSON2_CMCDMA_CCR_TCIE	BIT(1) /* Transfer Complete Interrupt Enable */
43 #define LOONGSON2_CMCDMA_CCR_HTIE	BIT(2) /* Half Transfer Complete Interrupt Enable */
44 #define LOONGSON2_CMCDMA_CCR_TEIE	BIT(3) /* Transfer Error Interrupt Enable */
45 #define LOONGSON2_CMCDMA_CCR_DIR	BIT(4) /* Data Transfer Direction */
46 #define LOONGSON2_CMCDMA_CCR_CIRC	BIT(5) /* Circular mode */
47 #define LOONGSON2_CMCDMA_CCR_PINC	BIT(6) /* Peripheral increment mode */
48 #define LOONGSON2_CMCDMA_CCR_MINC	BIT(7) /* Memory increment mode */
49 #define LOONGSON2_CMCDMA_CCR_PSIZE_MASK	GENMASK(9, 8)
50 #define LOONGSON2_CMCDMA_CCR_MSIZE_MASK	GENMASK(11, 10)
51 #define LOONGSON2_CMCDMA_CCR_PL_MASK	GENMASK(13, 12)
52 #define LOONGSON2_CMCDMA_CCR_M2M	BIT(14)
53 
54 #define LOONGSON2_CMCDMA_CCR_CFG_MASK	\
55 	(LOONGSON2_CMCDMA_CCR_PINC | LOONGSON2_CMCDMA_CCR_MINC | LOONGSON2_CMCDMA_CCR_PL_MASK)
56 
57 #define LOONGSON2_CMCDMA_CCR_IRQ_MASK	\
58 	(LOONGSON2_CMCDMA_CCR_TCIE | LOONGSON2_CMCDMA_CCR_HTIE | LOONGSON2_CMCDMA_CCR_TEIE)
59 
60 #define LOONGSON2_CMCDMA_STREAM_MASK	\
61 	(LOONGSON2_CMCDMA_CCR_CFG_MASK | LOONGSON2_CMCDMA_CCR_IRQ_MASK)
62 
63 #define LOONGSON2_CMCDMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
64 					 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
65 					 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
66 
67 #define LOONSON2_CMCDMA_MAX_DATA_ITEMS	SZ_64K
68 
69 struct loongson2_cmc_dma_chan_reg {
70 	u32 ccr;
71 	u32 cndtr;
72 	u32 cpar;
73 	u32 cmar;
74 };
75 
76 struct loongson2_cmc_dma_sg_req {
77 	u32 len;
78 	struct loongson2_cmc_dma_chan_reg chan_reg;
79 };
80 
81 struct loongson2_cmc_dma_desc {
82 	struct virt_dma_desc vdesc;
83 	bool cyclic;
84 	u32 num_sgs;
85 	struct loongson2_cmc_dma_sg_req sg_req[] __counted_by(num_sgs);
86 };
87 
88 struct loongson2_cmc_dma_chan {
89 	struct virt_dma_chan vchan;
90 	struct dma_slave_config	dma_sconfig;
91 	struct loongson2_cmc_dma_desc *desc;
92 	u32 id;
93 	u32 irq;
94 	u32 next_sg;
95 	struct loongson2_cmc_dma_chan_reg chan_reg;
96 };
97 
98 struct loongson2_cmc_dma_dev {
99 	struct dma_device ddev;
100 	struct clk *dma_clk;
101 	void __iomem *base;
102 	u32 nr_channels;
103 	u32 chan_reg_offset;
104 	struct loongson2_cmc_dma_chan chan[] __counted_by(nr_channels);
105 };
106 
107 struct loongson2_cmc_dma_config {
108 	u32 max_channels;
109 	u32 chan_reg_offset;
110 };
111 
112 static const struct loongson2_cmc_dma_config ls2k0300_cmc_dma_config = {
113 	.max_channels = 8,
114 	.chan_reg_offset = 0x14,
115 };
116 
117 static const struct loongson2_cmc_dma_config ls2k3000_cmc_dma_config = {
118 	.max_channels = 4,
119 	.chan_reg_offset = 0x18,
120 };
121 
122 static struct loongson2_cmc_dma_dev *lmdma_get_dev(struct loongson2_cmc_dma_chan *lchan)
123 {
124 	return container_of(lchan->vchan.chan.device, struct loongson2_cmc_dma_dev, ddev);
125 }
126 
127 static struct loongson2_cmc_dma_chan *to_lmdma_chan(struct dma_chan *chan)
128 {
129 	return container_of(chan, struct loongson2_cmc_dma_chan, vchan.chan);
130 }
131 
132 static struct loongson2_cmc_dma_desc *to_lmdma_desc(struct virt_dma_desc *vdesc)
133 {
134 	return container_of(vdesc, struct loongson2_cmc_dma_desc, vdesc);
135 }
136 
137 static struct device *chan2dev(struct loongson2_cmc_dma_chan *lchan)
138 {
139 	return &lchan->vchan.chan.dev->device;
140 }
141 
142 static u32 loongson2_cmc_dma_read(struct loongson2_cmc_dma_dev *lddev, u32 reg, u32 id)
143 {
144 	return readl(lddev->base + (reg + lddev->chan_reg_offset * id));
145 }
146 
147 static void loongson2_cmc_dma_write(struct loongson2_cmc_dma_dev *lddev, u32 reg, u32 id, u32 val)
148 {
149 	writel(val, lddev->base + (reg + lddev->chan_reg_offset * id));
150 }
151 
152 static int loongson2_cmc_dma_get_width(enum dma_slave_buswidth width)
153 {
154 	switch (width) {
155 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
156 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
157 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
158 		return ffs(width) - 1;
159 	default:
160 		return -EINVAL;
161 	}
162 }
163 
164 static int loongson2_cmc_dma_slave_config(struct dma_chan *chan, struct dma_slave_config *config)
165 {
166 	struct loongson2_cmc_dma_chan *lchan = to_lmdma_chan(chan);
167 
168 	memcpy(&lchan->dma_sconfig, config, sizeof(*config));
169 
170 	return 0;
171 }
172 
173 static void loongson2_cmc_dma_irq_clear(struct loongson2_cmc_dma_chan *lchan, u32 flags)
174 {
175 	struct loongson2_cmc_dma_dev *lddev = lmdma_get_dev(lchan);
176 	u32 ifcr;
177 
178 	ifcr = flags << (4 * lchan->id);
179 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_IFCR, 0, ifcr);
180 }
181 
182 static void loongson2_cmc_dma_stop(struct loongson2_cmc_dma_chan *lchan)
183 {
184 	struct loongson2_cmc_dma_dev *lddev = lmdma_get_dev(lchan);
185 	u32 ccr;
186 
187 	ccr = loongson2_cmc_dma_read(lddev, LOONGSON2_CMCDMA_CCR, lchan->id);
188 	ccr &= ~(LOONGSON2_CMCDMA_CCR_IRQ_MASK | LOONGSON2_CMCDMA_CCR_EN);
189 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CCR, lchan->id, ccr);
190 
191 	loongson2_cmc_dma_irq_clear(lchan, LOONGSON2_CMCDMA_MASKI);
192 }
193 
194 static int loongson2_cmc_dma_terminate_all(struct dma_chan *chan)
195 {
196 	struct loongson2_cmc_dma_chan *lchan = to_lmdma_chan(chan);
197 
198 	LIST_HEAD(head);
199 
200 	scoped_guard(spinlock_irqsave, &lchan->vchan.lock) {
201 		if (lchan->desc) {
202 			vchan_terminate_vdesc(&lchan->desc->vdesc);
203 			loongson2_cmc_dma_stop(lchan);
204 			lchan->desc = NULL;
205 		}
206 		vchan_get_all_descriptors(&lchan->vchan, &head);
207 	}
208 
209 	vchan_dma_desc_free_list(&lchan->vchan, &head);
210 
211 	return 0;
212 }
213 
214 static void loongson2_cmc_dma_synchronize(struct dma_chan *chan)
215 {
216 	struct loongson2_cmc_dma_chan *lchan = to_lmdma_chan(chan);
217 
218 	vchan_synchronize(&lchan->vchan);
219 }
220 
221 static void loongson2_cmc_dma_start_transfer(struct loongson2_cmc_dma_chan *lchan)
222 {
223 	struct loongson2_cmc_dma_dev *lddev = lmdma_get_dev(lchan);
224 	struct loongson2_cmc_dma_sg_req *sg_req;
225 	struct loongson2_cmc_dma_chan_reg *reg;
226 	struct virt_dma_desc *vdesc;
227 
228 	loongson2_cmc_dma_stop(lchan);
229 
230 	if (!lchan->desc) {
231 		vdesc = vchan_next_desc(&lchan->vchan);
232 		if (!vdesc)
233 			return;
234 
235 		list_del(&vdesc->node);
236 		lchan->desc = to_lmdma_desc(vdesc);
237 		lchan->next_sg = 0;
238 	}
239 
240 	if (lchan->next_sg == lchan->desc->num_sgs)
241 		lchan->next_sg = 0;
242 
243 	sg_req = &lchan->desc->sg_req[lchan->next_sg];
244 	reg = &sg_req->chan_reg;
245 
246 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CCR, lchan->id, reg->ccr);
247 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CNDTR, lchan->id, reg->cndtr);
248 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CPAR, lchan->id, reg->cpar);
249 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CMAR, lchan->id, reg->cmar);
250 
251 	lchan->next_sg++;
252 
253 	/* Start DMA */
254 	reg->ccr |= LOONGSON2_CMCDMA_CCR_EN;
255 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CCR, lchan->id, reg->ccr);
256 }
257 
258 static void loongson2_cmc_dma_configure_next_sg(struct loongson2_cmc_dma_chan *lchan)
259 {
260 	struct loongson2_cmc_dma_dev *lddev = lmdma_get_dev(lchan);
261 	struct loongson2_cmc_dma_sg_req *sg_req;
262 	u32 ccr, id = lchan->id;
263 
264 	if (lchan->next_sg == lchan->desc->num_sgs)
265 		lchan->next_sg = 0;
266 
267 	/* Stop to update mem addr */
268 	ccr = loongson2_cmc_dma_read(lddev, LOONGSON2_CMCDMA_CCR, id);
269 	ccr &= ~LOONGSON2_CMCDMA_CCR_EN;
270 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CCR, id, ccr);
271 
272 	sg_req = &lchan->desc->sg_req[lchan->next_sg];
273 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CMAR, id, sg_req->chan_reg.cmar);
274 
275 	/* Start transition */
276 	ccr |= LOONGSON2_CMCDMA_CCR_EN;
277 	loongson2_cmc_dma_write(lddev, LOONGSON2_CMCDMA_CCR, id, ccr);
278 }
279 
280 static void loongson2_cmc_dma_handle_chan_done(struct loongson2_cmc_dma_chan *lchan)
281 {
282 	if (!lchan->desc)
283 		return;
284 
285 	if (lchan->desc->cyclic) {
286 		vchan_cyclic_callback(&lchan->desc->vdesc);
287 		/* LOONGSON2_CMCDMA_CCR_CIRC mode don't need update register */
288 		if (lchan->desc->num_sgs == 1)
289 			return;
290 		loongson2_cmc_dma_configure_next_sg(lchan);
291 		lchan->next_sg++;
292 	} else {
293 		if (lchan->next_sg == lchan->desc->num_sgs) {
294 			vchan_cookie_complete(&lchan->desc->vdesc);
295 			lchan->desc = NULL;
296 		}
297 		loongson2_cmc_dma_start_transfer(lchan);
298 	}
299 }
300 
301 static irqreturn_t loongson2_cmc_dma_chan_irq(int irq, void *devid)
302 {
303 	struct loongson2_cmc_dma_chan *lchan = devid;
304 	struct loongson2_cmc_dma_dev *lddev = lmdma_get_dev(lchan);
305 	struct device *dev = chan2dev(lchan);
306 	u32 ists, status, ccr;
307 
308 	scoped_guard(spinlock, &lchan->vchan.lock) {
309 		ccr = loongson2_cmc_dma_read(lddev, LOONGSON2_CMCDMA_CCR, lchan->id);
310 		ists = loongson2_cmc_dma_read(lddev, LOONGSON2_CMCDMA_ISR, 0);
311 		status = (ists >> (4 * lchan->id)) & LOONGSON2_CMCDMA_MASKI;
312 
313 		loongson2_cmc_dma_irq_clear(lchan, status);
314 
315 		if (status & LOONGSON2_CMCDMA_TCI) {
316 			loongson2_cmc_dma_handle_chan_done(lchan);
317 			status &= ~LOONGSON2_CMCDMA_TCI;
318 		}
319 
320 		if (status & LOONGSON2_CMCDMA_HTI)
321 			status &= ~LOONGSON2_CMCDMA_HTI;
322 
323 		if (status & LOONGSON2_CMCDMA_TEI) {
324 			dev_err(dev, "DMA Transform Error.\n");
325 			if (!(ccr & LOONGSON2_CMCDMA_CCR_EN))
326 				dev_err(dev, "Channel disabled by HW.\n");
327 		}
328 	}
329 
330 	return IRQ_HANDLED;
331 }
332 
333 static void loongson2_cmc_dma_issue_pending(struct dma_chan *chan)
334 {
335 	struct loongson2_cmc_dma_chan *lchan = to_lmdma_chan(chan);
336 
337 	guard(spinlock_irqsave)(&lchan->vchan.lock);
338 
339 	if (vchan_issue_pending(&lchan->vchan) && !lchan->desc) {
340 		dev_dbg(chan2dev(lchan), "vchan %pK: issued\n", &lchan->vchan);
341 		loongson2_cmc_dma_start_transfer(lchan);
342 	}
343 }
344 
345 static int loongson2_cmc_dma_set_xfer_param(struct loongson2_cmc_dma_chan *lchan,
346 					    enum dma_transfer_direction direction,
347 					    enum dma_slave_buswidth *buswidth, u32 buf_len)
348 {
349 	struct dma_slave_config	sconfig = lchan->dma_sconfig;
350 	struct device *dev = chan2dev(lchan);
351 	int dev_width;
352 	u32 ccr;
353 
354 	switch (direction) {
355 	case DMA_MEM_TO_DEV:
356 		dev_width = loongson2_cmc_dma_get_width(sconfig.dst_addr_width);
357 		if (dev_width < 0) {
358 			dev_err(dev, "DMA_MEM_TO_DEV bus width not supported\n");
359 			return dev_width;
360 		}
361 		lchan->chan_reg.cpar = sconfig.dst_addr;
362 		ccr = LOONGSON2_CMCDMA_CCR_DIR;
363 		*buswidth = sconfig.dst_addr_width;
364 		break;
365 	case DMA_DEV_TO_MEM:
366 		dev_width = loongson2_cmc_dma_get_width(sconfig.src_addr_width);
367 		if (dev_width < 0) {
368 			dev_err(dev, "DMA_DEV_TO_MEM bus width not supported\n");
369 			return dev_width;
370 		}
371 		lchan->chan_reg.cpar = sconfig.src_addr;
372 		ccr = LOONGSON2_CMCDMA_CCR_MINC;
373 		*buswidth = sconfig.src_addr_width;
374 		break;
375 	default:
376 		return -EINVAL;
377 	}
378 
379 	ccr |= FIELD_PREP(LOONGSON2_CMCDMA_CCR_PSIZE_MASK, dev_width) |
380 	       FIELD_PREP(LOONGSON2_CMCDMA_CCR_MSIZE_MASK, dev_width);
381 
382 	/* Set DMA control register */
383 	lchan->chan_reg.ccr &= ~(LOONGSON2_CMCDMA_CCR_PSIZE_MASK | LOONGSON2_CMCDMA_CCR_MSIZE_MASK);
384 	lchan->chan_reg.ccr |= ccr;
385 
386 	return 0;
387 }
388 
389 static struct dma_async_tx_descriptor *
390 loongson2_cmc_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, u32 sg_len,
391 				enum dma_transfer_direction direction,
392 				unsigned long flags, void *context)
393 {
394 	struct loongson2_cmc_dma_chan *lchan = to_lmdma_chan(chan);
395 	struct loongson2_cmc_dma_desc *desc;
396 	enum dma_slave_buswidth buswidth;
397 	struct scatterlist *sg;
398 	u32 num_items, i;
399 	int ret;
400 
401 	desc = kzalloc_flex(*desc, sg_req, sg_len, GFP_NOWAIT);
402 	if (!desc)
403 		return ERR_PTR(-ENOMEM);
404 
405 	for_each_sg(sgl, sg, sg_len, i) {
406 		ret = loongson2_cmc_dma_set_xfer_param(lchan, direction, &buswidth, sg_dma_len(sg));
407 		if (ret)
408 			return ERR_PTR(ret);
409 
410 		num_items = DIV_ROUND_UP(sg_dma_len(sg), buswidth);
411 		if (num_items >= LOONSON2_CMCDMA_MAX_DATA_ITEMS) {
412 			dev_err(chan2dev(lchan), "Number of items not supported\n");
413 			kfree(desc);
414 			return ERR_PTR(-EINVAL);
415 		}
416 
417 		desc->sg_req[i].len = sg_dma_len(sg);
418 		desc->sg_req[i].chan_reg.ccr = lchan->chan_reg.ccr;
419 		desc->sg_req[i].chan_reg.cpar = lchan->chan_reg.cpar;
420 		desc->sg_req[i].chan_reg.cmar = sg_dma_address(sg);
421 		desc->sg_req[i].chan_reg.cndtr = num_items;
422 	}
423 
424 	desc->num_sgs = sg_len;
425 	desc->cyclic = false;
426 
427 	return vchan_tx_prep(&lchan->vchan, &desc->vdesc, flags);
428 }
429 
430 static struct dma_async_tx_descriptor *
431 loongson2_cmc_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
432 				  size_t period_len, enum dma_transfer_direction direction,
433 				  unsigned long flags)
434 {
435 	struct loongson2_cmc_dma_chan *lchan = to_lmdma_chan(chan);
436 	struct loongson2_cmc_dma_desc *desc;
437 	enum dma_slave_buswidth buswidth;
438 	u32 num_periods, num_items, i;
439 	int ret;
440 
441 	if (unlikely(buf_len % period_len))
442 		return ERR_PTR(-EINVAL);
443 
444 	ret = loongson2_cmc_dma_set_xfer_param(lchan, direction, &buswidth, period_len);
445 	if (ret)
446 		return ERR_PTR(ret);
447 
448 	num_items = DIV_ROUND_UP(period_len, buswidth);
449 	if (num_items >= LOONSON2_CMCDMA_MAX_DATA_ITEMS) {
450 		dev_err(chan2dev(lchan), "Number of items not supported\n");
451 		return ERR_PTR(-EINVAL);
452 	}
453 
454 	/* Enable Circular mode */
455 	if (buf_len == period_len)
456 		lchan->chan_reg.ccr |= LOONGSON2_CMCDMA_CCR_CIRC;
457 
458 	num_periods = DIV_ROUND_UP(buf_len, period_len);
459 	desc = kzalloc_flex(*desc, sg_req, num_periods, GFP_NOWAIT);
460 	if (!desc)
461 		return ERR_PTR(-ENOMEM);
462 
463 	for (i = 0; i < num_periods; i++) {
464 		desc->sg_req[i].len = period_len;
465 		desc->sg_req[i].chan_reg.ccr = lchan->chan_reg.ccr;
466 		desc->sg_req[i].chan_reg.cpar = lchan->chan_reg.cpar;
467 		desc->sg_req[i].chan_reg.cmar = buf_addr;
468 		desc->sg_req[i].chan_reg.cndtr = num_items;
469 		buf_addr += period_len;
470 	}
471 
472 	desc->num_sgs = num_periods;
473 	desc->cyclic = true;
474 
475 	return vchan_tx_prep(&lchan->vchan, &desc->vdesc, flags);
476 }
477 
478 static size_t loongson2_cmc_dma_desc_residue(struct loongson2_cmc_dma_chan *lchan,
479 					     struct loongson2_cmc_dma_desc *desc, u32 next_sg)
480 {
481 	struct loongson2_cmc_dma_dev *lddev = lmdma_get_dev(lchan);
482 	u32 residue, width, ndtr, ccr, i;
483 
484 	ccr = loongson2_cmc_dma_read(lddev, LOONGSON2_CMCDMA_CCR, lchan->id);
485 	width = FIELD_GET(LOONGSON2_CMCDMA_CCR_PSIZE_MASK, ccr);
486 
487 	ndtr = loongson2_cmc_dma_read(lddev, LOONGSON2_CMCDMA_CNDTR, lchan->id);
488 	residue = ndtr << width;
489 
490 	if (lchan->desc->cyclic && next_sg == 0)
491 		return residue;
492 
493 	for (i = next_sg; i < desc->num_sgs; i++)
494 		residue += desc->sg_req[i].len;
495 
496 	return residue;
497 }
498 
499 static enum dma_status loongson2_cmc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
500 						   struct dma_tx_state *state)
501 {
502 	struct loongson2_cmc_dma_chan *lchan = to_lmdma_chan(chan);
503 	struct virt_dma_desc *vdesc;
504 	enum dma_status status;
505 
506 	status = dma_cookie_status(chan, cookie, state);
507 	if (status == DMA_COMPLETE || !state)
508 		return status;
509 
510 	scoped_guard(spinlock_irqsave, &lchan->vchan.lock) {
511 		vdesc = vchan_find_desc(&lchan->vchan, cookie);
512 		if (lchan->desc && cookie == lchan->desc->vdesc.tx.cookie)
513 			state->residue = loongson2_cmc_dma_desc_residue(lchan, lchan->desc,
514 									lchan->next_sg);
515 		else if (vdesc)
516 			state->residue = loongson2_cmc_dma_desc_residue(lchan,
517 									to_lmdma_desc(vdesc), 0);
518 	}
519 
520 	return status;
521 }
522 
523 static void loongson2_cmc_dma_free_chan_resources(struct dma_chan *chan)
524 {
525 	vchan_free_chan_resources(to_virt_chan(chan));
526 }
527 
528 static void loongson2_cmc_dma_desc_free(struct virt_dma_desc *vdesc)
529 {
530 	kfree(to_lmdma_desc(vdesc));
531 }
532 
533 static bool loongson2_cmc_dma_acpi_filter(struct dma_chan *chan, void *param)
534 {
535 	struct loongson2_cmc_dma_chan *lchan = to_lmdma_chan(chan);
536 	struct acpi_dma_spec *dma_spec = param;
537 
538 	memset(&lchan->chan_reg, 0, sizeof(struct loongson2_cmc_dma_chan_reg));
539 	lchan->chan_reg.ccr = dma_spec->chan_id & LOONGSON2_CMCDMA_STREAM_MASK;
540 
541 	return true;
542 }
543 
544 static int loongson2_cmc_dma_acpi_controller_register(struct loongson2_cmc_dma_dev *lddev)
545 {
546 	struct device *dev = lddev->ddev.dev;
547 	struct acpi_dma_filter_info *info;
548 
549 	if (!is_acpi_node(dev_fwnode(dev)))
550 		return 0;
551 
552 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
553 	if (!info)
554 		return -ENOMEM;
555 
556 	dma_cap_zero(info->dma_cap);
557 	info->dma_cap = lddev->ddev.cap_mask;
558 	info->filter_fn = loongson2_cmc_dma_acpi_filter;
559 
560 	return devm_acpi_dma_controller_register(dev, acpi_dma_simple_xlate, info);
561 }
562 
563 static struct dma_chan *loongson2_cmc_dma_of_xlate(struct of_phandle_args *dma_spec,
564 						   struct of_dma *ofdma)
565 {
566 	struct loongson2_cmc_dma_dev *lddev = ofdma->of_dma_data;
567 	struct device *dev = lddev->ddev.dev;
568 	struct loongson2_cmc_dma_chan *lchan;
569 	struct dma_chan *chan;
570 
571 	if (dma_spec->args_count < 2)
572 		return ERR_PTR(-EINVAL);
573 
574 	if (dma_spec->args[0] >= lddev->nr_channels) {
575 		dev_err(dev, "Invalid channel id.\n");
576 		return ERR_PTR(-EINVAL);
577 	}
578 
579 	lchan = &lddev->chan[dma_spec->args[0]];
580 	chan = dma_get_slave_channel(&lchan->vchan.chan);
581 	if (!chan) {
582 		dev_err(dev, "No more channels available.\n");
583 		return ERR_PTR(-EINVAL);
584 	}
585 
586 	memset(&lchan->chan_reg, 0, sizeof(struct loongson2_cmc_dma_chan_reg));
587 	lchan->chan_reg.ccr = dma_spec->args[1] & LOONGSON2_CMCDMA_STREAM_MASK;
588 
589 	return chan;
590 }
591 
592 static int loongson2_cmc_dma_of_controller_register(struct loongson2_cmc_dma_dev *lddev)
593 {
594 	struct device *dev = lddev->ddev.dev;
595 
596 	if (!is_of_node(dev_fwnode(dev)))
597 		return 0;
598 
599 	return of_dma_controller_register(dev->of_node, loongson2_cmc_dma_of_xlate, lddev);
600 }
601 
602 static int loongson2_cmc_dma_probe(struct platform_device *pdev)
603 {
604 	const struct loongson2_cmc_dma_config *config;
605 	struct loongson2_cmc_dma_chan *lchan;
606 	struct loongson2_cmc_dma_dev *lddev;
607 	struct device *dev = &pdev->dev;
608 	struct dma_device *ddev;
609 	u32 nr_chans, i;
610 	int ret;
611 
612 	config = (const struct loongson2_cmc_dma_config *)device_get_match_data(dev);
613 	if (!config)
614 		return -EINVAL;
615 
616 	ret = device_property_read_u32(dev, "dma-channels", &nr_chans);
617 	if (ret || nr_chans > config->max_channels) {
618 		dev_err(dev, "missing or invalid dma-channels property\n");
619 		nr_chans = config->max_channels;
620 	}
621 
622 	lddev = devm_kzalloc(dev, struct_size(lddev, chan, nr_chans), GFP_KERNEL);
623 	if (!lddev)
624 		return -ENOMEM;
625 
626 	lddev->base = devm_platform_ioremap_resource(pdev, 0);
627 	if (IS_ERR(lddev->base))
628 		return PTR_ERR(lddev->base);
629 
630 	platform_set_drvdata(pdev, lddev);
631 	lddev->nr_channels = nr_chans;
632 	lddev->chan_reg_offset = config->chan_reg_offset;
633 
634 	lddev->dma_clk = devm_clk_get_optional_enabled(dev, NULL);
635 	if (IS_ERR(lddev->dma_clk))
636 		return dev_err_probe(dev, PTR_ERR(lddev->dma_clk), "Failed to get dma clock\n");
637 
638 	ddev = &lddev->ddev;
639 	ddev->dev = dev;
640 
641 	dma_cap_zero(ddev->cap_mask);
642 	dma_cap_set(DMA_SLAVE, ddev->cap_mask);
643 	dma_cap_set(DMA_PRIVATE, ddev->cap_mask);
644 	dma_cap_set(DMA_CYCLIC, ddev->cap_mask);
645 
646 	ddev->device_free_chan_resources = loongson2_cmc_dma_free_chan_resources;
647 	ddev->device_config = loongson2_cmc_dma_slave_config;
648 	ddev->device_prep_slave_sg = loongson2_cmc_dma_prep_slave_sg;
649 	ddev->device_prep_dma_cyclic = loongson2_cmc_dma_prep_dma_cyclic;
650 	ddev->device_issue_pending = loongson2_cmc_dma_issue_pending;
651 	ddev->device_synchronize = loongson2_cmc_dma_synchronize;
652 	ddev->device_tx_status = loongson2_cmc_dma_tx_status;
653 	ddev->device_terminate_all = loongson2_cmc_dma_terminate_all;
654 
655 	ddev->max_sg_burst = LOONSON2_CMCDMA_MAX_DATA_ITEMS;
656 	ddev->src_addr_widths = LOONGSON2_CMCDMA_BUSWIDTHS;
657 	ddev->dst_addr_widths = LOONGSON2_CMCDMA_BUSWIDTHS;
658 	ddev->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
659 	INIT_LIST_HEAD(&ddev->channels);
660 
661 	for (i = 0; i < nr_chans; i++) {
662 		lchan = &lddev->chan[i];
663 
664 		lchan->id = i;
665 		lchan->vchan.desc_free = loongson2_cmc_dma_desc_free;
666 		vchan_init(&lchan->vchan, ddev);
667 	}
668 
669 	ret = dmaenginem_async_device_register(ddev);
670 	if (ret)
671 		return dev_err_probe(dev, ret, "Failed to register DMA engine device.\n");
672 
673 	for (i = 0; i < nr_chans; i++) {
674 		lchan = &lddev->chan[i];
675 
676 		lchan->irq = platform_get_irq(pdev, i);
677 		if (lchan->irq < 0)
678 			return lchan->irq;
679 
680 		ret = devm_request_irq(dev, lchan->irq, loongson2_cmc_dma_chan_irq, IRQF_SHARED,
681 				       dev_name(chan2dev(lchan)), lchan);
682 		if (ret)
683 			return ret;
684 	}
685 
686 	ret = loongson2_cmc_dma_acpi_controller_register(lddev);
687 	if (ret)
688 		return dev_err_probe(dev, ret, "Failed to register dma controller with ACPI.\n");
689 
690 	ret = loongson2_cmc_dma_of_controller_register(lddev);
691 	if (ret)
692 		return dev_err_probe(dev, ret, "Failed to register dma controller with FDT.\n");
693 
694 	dev_info(dev, "Loongson-2 Multi-Channel DMA Controller registered successfully.\n");
695 
696 	return 0;
697 }
698 
699 static void loongson2_cmc_dma_remove(struct platform_device *pdev)
700 {
701 	of_dma_controller_free(pdev->dev.of_node);
702 }
703 
704 static const struct of_device_id loongson2_cmc_dma_of_match[] = {
705 	{ .compatible = "loongson,ls2k0300-dma", .data = &ls2k0300_cmc_dma_config },
706 	{ .compatible = "loongson,ls2k3000-dma", .data = &ls2k3000_cmc_dma_config },
707 	{ /* sentinel */ }
708 };
709 MODULE_DEVICE_TABLE(of, loongson2_cmc_dma_of_match);
710 
711 static const struct acpi_device_id loongson2_cmc_dma_acpi_match[] = {
712 	{ "LOON0014", .driver_data = (kernel_ulong_t)&ls2k3000_cmc_dma_config },
713 	{ /* sentinel */ }
714 };
715 MODULE_DEVICE_TABLE(acpi, loongson2_cmc_dma_acpi_match);
716 
717 static struct platform_driver loongson2_cmc_dma_driver = {
718 	.driver = {
719 		.name = "loongson2-apb-cmc-dma",
720 		.of_match_table = loongson2_cmc_dma_of_match,
721 		.acpi_match_table = loongson2_cmc_dma_acpi_match,
722 	},
723 	.probe = loongson2_cmc_dma_probe,
724 	.remove = loongson2_cmc_dma_remove,
725 };
726 module_platform_driver(loongson2_cmc_dma_driver);
727 
728 MODULE_DESCRIPTION("Loongson-2 Chain Multi-Channel DMA Controller driver");
729 MODULE_AUTHOR("Loongson Technology Corporation Limited");
730 MODULE_LICENSE("GPL");
731