xref: /openbmc/linux/drivers/dma/dma-jz4780.c (revision 0e96cf7f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Ingenic JZ4780 DMA controller
4  *
5  * Copyright (c) 2015 Imagination Technologies
6  * Author: Alex Smith <alex@alex-smith.me.uk>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/dmapool.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_device.h>
16 #include <linux/of_dma.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 
20 #include "dmaengine.h"
21 #include "virt-dma.h"
22 
23 /* Global registers. */
24 #define JZ_DMA_REG_DMAC		0x00
25 #define JZ_DMA_REG_DIRQP	0x04
26 #define JZ_DMA_REG_DDR		0x08
27 #define JZ_DMA_REG_DDRS		0x0c
28 #define JZ_DMA_REG_DCKE		0x10
29 #define JZ_DMA_REG_DCKES	0x14
30 #define JZ_DMA_REG_DCKEC	0x18
31 #define JZ_DMA_REG_DMACP	0x1c
32 #define JZ_DMA_REG_DSIRQP	0x20
33 #define JZ_DMA_REG_DSIRQM	0x24
34 #define JZ_DMA_REG_DCIRQP	0x28
35 #define JZ_DMA_REG_DCIRQM	0x2c
36 
37 /* Per-channel registers. */
38 #define JZ_DMA_REG_CHAN(n)	(n * 0x20)
39 #define JZ_DMA_REG_DSA		0x00
40 #define JZ_DMA_REG_DTA		0x04
41 #define JZ_DMA_REG_DTC		0x08
42 #define JZ_DMA_REG_DRT		0x0c
43 #define JZ_DMA_REG_DCS		0x10
44 #define JZ_DMA_REG_DCM		0x14
45 #define JZ_DMA_REG_DDA		0x18
46 #define JZ_DMA_REG_DSD		0x1c
47 
48 #define JZ_DMA_DMAC_DMAE	BIT(0)
49 #define JZ_DMA_DMAC_AR		BIT(2)
50 #define JZ_DMA_DMAC_HLT		BIT(3)
51 #define JZ_DMA_DMAC_FAIC	BIT(27)
52 #define JZ_DMA_DMAC_FMSC	BIT(31)
53 
54 #define JZ_DMA_DRT_AUTO		0x8
55 
56 #define JZ_DMA_DCS_CTE		BIT(0)
57 #define JZ_DMA_DCS_HLT		BIT(2)
58 #define JZ_DMA_DCS_TT		BIT(3)
59 #define JZ_DMA_DCS_AR		BIT(4)
60 #define JZ_DMA_DCS_DES8		BIT(30)
61 
62 #define JZ_DMA_DCM_LINK		BIT(0)
63 #define JZ_DMA_DCM_TIE		BIT(1)
64 #define JZ_DMA_DCM_STDE		BIT(2)
65 #define JZ_DMA_DCM_TSZ_SHIFT	8
66 #define JZ_DMA_DCM_TSZ_MASK	(0x7 << JZ_DMA_DCM_TSZ_SHIFT)
67 #define JZ_DMA_DCM_DP_SHIFT	12
68 #define JZ_DMA_DCM_SP_SHIFT	14
69 #define JZ_DMA_DCM_DAI		BIT(22)
70 #define JZ_DMA_DCM_SAI		BIT(23)
71 
72 #define JZ_DMA_SIZE_4_BYTE	0x0
73 #define JZ_DMA_SIZE_1_BYTE	0x1
74 #define JZ_DMA_SIZE_2_BYTE	0x2
75 #define JZ_DMA_SIZE_16_BYTE	0x3
76 #define JZ_DMA_SIZE_32_BYTE	0x4
77 #define JZ_DMA_SIZE_64_BYTE	0x5
78 #define JZ_DMA_SIZE_128_BYTE	0x6
79 
80 #define JZ_DMA_WIDTH_32_BIT	0x0
81 #define JZ_DMA_WIDTH_8_BIT	0x1
82 #define JZ_DMA_WIDTH_16_BIT	0x2
83 
84 #define JZ_DMA_BUSWIDTHS	(BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)	 | \
85 				 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
86 				 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES))
87 
88 #define JZ4780_DMA_CTRL_OFFSET	0x1000
89 
90 /* macros for use with jz4780_dma_soc_data.flags */
91 #define JZ_SOC_DATA_ALLOW_LEGACY_DT	BIT(0)
92 #define JZ_SOC_DATA_PROGRAMMABLE_DMA	BIT(1)
93 #define JZ_SOC_DATA_PER_CHAN_PM		BIT(2)
94 #define JZ_SOC_DATA_NO_DCKES_DCKEC	BIT(3)
95 
96 /**
97  * struct jz4780_dma_hwdesc - descriptor structure read by the DMA controller.
98  * @dcm: value for the DCM (channel command) register
99  * @dsa: source address
100  * @dta: target address
101  * @dtc: transfer count (number of blocks of the transfer size specified in DCM
102  * to transfer) in the low 24 bits, offset of the next descriptor from the
103  * descriptor base address in the upper 8 bits.
104  */
105 struct jz4780_dma_hwdesc {
106 	uint32_t dcm;
107 	uint32_t dsa;
108 	uint32_t dta;
109 	uint32_t dtc;
110 };
111 
112 /* Size of allocations for hardware descriptor blocks. */
113 #define JZ_DMA_DESC_BLOCK_SIZE	PAGE_SIZE
114 #define JZ_DMA_MAX_DESC		\
115 	(JZ_DMA_DESC_BLOCK_SIZE / sizeof(struct jz4780_dma_hwdesc))
116 
117 struct jz4780_dma_desc {
118 	struct virt_dma_desc vdesc;
119 
120 	struct jz4780_dma_hwdesc *desc;
121 	dma_addr_t desc_phys;
122 	unsigned int count;
123 	enum dma_transaction_type type;
124 	uint32_t status;
125 };
126 
127 struct jz4780_dma_chan {
128 	struct virt_dma_chan vchan;
129 	unsigned int id;
130 	struct dma_pool *desc_pool;
131 
132 	uint32_t transfer_type;
133 	uint32_t transfer_shift;
134 	struct dma_slave_config	config;
135 
136 	struct jz4780_dma_desc *desc;
137 	unsigned int curr_hwdesc;
138 };
139 
140 struct jz4780_dma_soc_data {
141 	unsigned int nb_channels;
142 	unsigned int transfer_ord_max;
143 	unsigned long flags;
144 };
145 
146 struct jz4780_dma_dev {
147 	struct dma_device dma_device;
148 	void __iomem *chn_base;
149 	void __iomem *ctrl_base;
150 	struct clk *clk;
151 	unsigned int irq;
152 	const struct jz4780_dma_soc_data *soc_data;
153 
154 	uint32_t chan_reserved;
155 	struct jz4780_dma_chan chan[];
156 };
157 
158 struct jz4780_dma_filter_data {
159 	struct device_node *of_node;
160 	uint32_t transfer_type;
161 	int channel;
162 };
163 
164 static inline struct jz4780_dma_chan *to_jz4780_dma_chan(struct dma_chan *chan)
165 {
166 	return container_of(chan, struct jz4780_dma_chan, vchan.chan);
167 }
168 
169 static inline struct jz4780_dma_desc *to_jz4780_dma_desc(
170 	struct virt_dma_desc *vdesc)
171 {
172 	return container_of(vdesc, struct jz4780_dma_desc, vdesc);
173 }
174 
175 static inline struct jz4780_dma_dev *jz4780_dma_chan_parent(
176 	struct jz4780_dma_chan *jzchan)
177 {
178 	return container_of(jzchan->vchan.chan.device, struct jz4780_dma_dev,
179 			    dma_device);
180 }
181 
182 static inline uint32_t jz4780_dma_chn_readl(struct jz4780_dma_dev *jzdma,
183 	unsigned int chn, unsigned int reg)
184 {
185 	return readl(jzdma->chn_base + reg + JZ_DMA_REG_CHAN(chn));
186 }
187 
188 static inline void jz4780_dma_chn_writel(struct jz4780_dma_dev *jzdma,
189 	unsigned int chn, unsigned int reg, uint32_t val)
190 {
191 	writel(val, jzdma->chn_base + reg + JZ_DMA_REG_CHAN(chn));
192 }
193 
194 static inline uint32_t jz4780_dma_ctrl_readl(struct jz4780_dma_dev *jzdma,
195 	unsigned int reg)
196 {
197 	return readl(jzdma->ctrl_base + reg);
198 }
199 
200 static inline void jz4780_dma_ctrl_writel(struct jz4780_dma_dev *jzdma,
201 	unsigned int reg, uint32_t val)
202 {
203 	writel(val, jzdma->ctrl_base + reg);
204 }
205 
206 static inline void jz4780_dma_chan_enable(struct jz4780_dma_dev *jzdma,
207 	unsigned int chn)
208 {
209 	if (jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM) {
210 		unsigned int reg;
211 
212 		if (jzdma->soc_data->flags & JZ_SOC_DATA_NO_DCKES_DCKEC)
213 			reg = JZ_DMA_REG_DCKE;
214 		else
215 			reg = JZ_DMA_REG_DCKES;
216 
217 		jz4780_dma_ctrl_writel(jzdma, reg, BIT(chn));
218 	}
219 }
220 
221 static inline void jz4780_dma_chan_disable(struct jz4780_dma_dev *jzdma,
222 	unsigned int chn)
223 {
224 	if ((jzdma->soc_data->flags & JZ_SOC_DATA_PER_CHAN_PM) &&
225 			!(jzdma->soc_data->flags & JZ_SOC_DATA_NO_DCKES_DCKEC))
226 		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKEC, BIT(chn));
227 }
228 
229 static struct jz4780_dma_desc *jz4780_dma_desc_alloc(
230 	struct jz4780_dma_chan *jzchan, unsigned int count,
231 	enum dma_transaction_type type)
232 {
233 	struct jz4780_dma_desc *desc;
234 
235 	if (count > JZ_DMA_MAX_DESC)
236 		return NULL;
237 
238 	desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
239 	if (!desc)
240 		return NULL;
241 
242 	desc->desc = dma_pool_alloc(jzchan->desc_pool, GFP_NOWAIT,
243 				    &desc->desc_phys);
244 	if (!desc->desc) {
245 		kfree(desc);
246 		return NULL;
247 	}
248 
249 	desc->count = count;
250 	desc->type = type;
251 	return desc;
252 }
253 
254 static void jz4780_dma_desc_free(struct virt_dma_desc *vdesc)
255 {
256 	struct jz4780_dma_desc *desc = to_jz4780_dma_desc(vdesc);
257 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(vdesc->tx.chan);
258 
259 	dma_pool_free(jzchan->desc_pool, desc->desc, desc->desc_phys);
260 	kfree(desc);
261 }
262 
263 static uint32_t jz4780_dma_transfer_size(struct jz4780_dma_chan *jzchan,
264 	unsigned long val, uint32_t *shift)
265 {
266 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
267 	int ord = ffs(val) - 1;
268 
269 	/*
270 	 * 8 byte transfer sizes unsupported so fall back on 4. If it's larger
271 	 * than the maximum, just limit it. It is perfectly safe to fall back
272 	 * in this way since we won't exceed the maximum burst size supported
273 	 * by the device, the only effect is reduced efficiency. This is better
274 	 * than refusing to perform the request at all.
275 	 */
276 	if (ord == 3)
277 		ord = 2;
278 	else if (ord > jzdma->soc_data->transfer_ord_max)
279 		ord = jzdma->soc_data->transfer_ord_max;
280 
281 	*shift = ord;
282 
283 	switch (ord) {
284 	case 0:
285 		return JZ_DMA_SIZE_1_BYTE;
286 	case 1:
287 		return JZ_DMA_SIZE_2_BYTE;
288 	case 2:
289 		return JZ_DMA_SIZE_4_BYTE;
290 	case 4:
291 		return JZ_DMA_SIZE_16_BYTE;
292 	case 5:
293 		return JZ_DMA_SIZE_32_BYTE;
294 	case 6:
295 		return JZ_DMA_SIZE_64_BYTE;
296 	default:
297 		return JZ_DMA_SIZE_128_BYTE;
298 	}
299 }
300 
301 static int jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
302 	struct jz4780_dma_hwdesc *desc, dma_addr_t addr, size_t len,
303 	enum dma_transfer_direction direction)
304 {
305 	struct dma_slave_config *config = &jzchan->config;
306 	uint32_t width, maxburst, tsz;
307 
308 	if (direction == DMA_MEM_TO_DEV) {
309 		desc->dcm = JZ_DMA_DCM_SAI;
310 		desc->dsa = addr;
311 		desc->dta = config->dst_addr;
312 
313 		width = config->dst_addr_width;
314 		maxburst = config->dst_maxburst;
315 	} else {
316 		desc->dcm = JZ_DMA_DCM_DAI;
317 		desc->dsa = config->src_addr;
318 		desc->dta = addr;
319 
320 		width = config->src_addr_width;
321 		maxburst = config->src_maxburst;
322 	}
323 
324 	/*
325 	 * This calculates the maximum transfer size that can be used with the
326 	 * given address, length, width and maximum burst size. The address
327 	 * must be aligned to the transfer size, the total length must be
328 	 * divisible by the transfer size, and we must not use more than the
329 	 * maximum burst specified by the user.
330 	 */
331 	tsz = jz4780_dma_transfer_size(jzchan, addr | len | (width * maxburst),
332 				       &jzchan->transfer_shift);
333 
334 	switch (width) {
335 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
336 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
337 		break;
338 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
339 		width = JZ_DMA_WIDTH_32_BIT;
340 		break;
341 	default:
342 		return -EINVAL;
343 	}
344 
345 	desc->dcm |= tsz << JZ_DMA_DCM_TSZ_SHIFT;
346 	desc->dcm |= width << JZ_DMA_DCM_SP_SHIFT;
347 	desc->dcm |= width << JZ_DMA_DCM_DP_SHIFT;
348 
349 	desc->dtc = len >> jzchan->transfer_shift;
350 	return 0;
351 }
352 
353 static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
354 	struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
355 	enum dma_transfer_direction direction, unsigned long flags,
356 	void *context)
357 {
358 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
359 	struct jz4780_dma_desc *desc;
360 	unsigned int i;
361 	int err;
362 
363 	desc = jz4780_dma_desc_alloc(jzchan, sg_len, DMA_SLAVE);
364 	if (!desc)
365 		return NULL;
366 
367 	for (i = 0; i < sg_len; i++) {
368 		err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i],
369 					      sg_dma_address(&sgl[i]),
370 					      sg_dma_len(&sgl[i]),
371 					      direction);
372 		if (err < 0) {
373 			jz4780_dma_desc_free(&jzchan->desc->vdesc);
374 			return NULL;
375 		}
376 
377 		desc->desc[i].dcm |= JZ_DMA_DCM_TIE;
378 
379 		if (i != (sg_len - 1)) {
380 			/* Automatically proceeed to the next descriptor. */
381 			desc->desc[i].dcm |= JZ_DMA_DCM_LINK;
382 
383 			/*
384 			 * The upper 8 bits of the DTC field in the descriptor
385 			 * must be set to (offset from descriptor base of next
386 			 * descriptor >> 4).
387 			 */
388 			desc->desc[i].dtc |=
389 				(((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
390 		}
391 	}
392 
393 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
394 }
395 
396 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_cyclic(
397 	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
398 	size_t period_len, enum dma_transfer_direction direction,
399 	unsigned long flags)
400 {
401 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
402 	struct jz4780_dma_desc *desc;
403 	unsigned int periods, i;
404 	int err;
405 
406 	if (buf_len % period_len)
407 		return NULL;
408 
409 	periods = buf_len / period_len;
410 
411 	desc = jz4780_dma_desc_alloc(jzchan, periods, DMA_CYCLIC);
412 	if (!desc)
413 		return NULL;
414 
415 	for (i = 0; i < periods; i++) {
416 		err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i], buf_addr,
417 					      period_len, direction);
418 		if (err < 0) {
419 			jz4780_dma_desc_free(&jzchan->desc->vdesc);
420 			return NULL;
421 		}
422 
423 		buf_addr += period_len;
424 
425 		/*
426 		 * Set the link bit to indicate that the controller should
427 		 * automatically proceed to the next descriptor. In
428 		 * jz4780_dma_begin(), this will be cleared if we need to issue
429 		 * an interrupt after each period.
430 		 */
431 		desc->desc[i].dcm |= JZ_DMA_DCM_TIE | JZ_DMA_DCM_LINK;
432 
433 		/*
434 		 * The upper 8 bits of the DTC field in the descriptor must be
435 		 * set to (offset from descriptor base of next descriptor >> 4).
436 		 * If this is the last descriptor, link it back to the first,
437 		 * i.e. leave offset set to 0, otherwise point to the next one.
438 		 */
439 		if (i != (periods - 1)) {
440 			desc->desc[i].dtc |=
441 				(((i + 1) * sizeof(*desc->desc)) >> 4) << 24;
442 		}
443 	}
444 
445 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
446 }
447 
448 static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_memcpy(
449 	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
450 	size_t len, unsigned long flags)
451 {
452 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
453 	struct jz4780_dma_desc *desc;
454 	uint32_t tsz;
455 
456 	desc = jz4780_dma_desc_alloc(jzchan, 1, DMA_MEMCPY);
457 	if (!desc)
458 		return NULL;
459 
460 	tsz = jz4780_dma_transfer_size(jzchan, dest | src | len,
461 				       &jzchan->transfer_shift);
462 
463 	jzchan->transfer_type = JZ_DMA_DRT_AUTO;
464 
465 	desc->desc[0].dsa = src;
466 	desc->desc[0].dta = dest;
467 	desc->desc[0].dcm = JZ_DMA_DCM_TIE | JZ_DMA_DCM_SAI | JZ_DMA_DCM_DAI |
468 			    tsz << JZ_DMA_DCM_TSZ_SHIFT |
469 			    JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_SP_SHIFT |
470 			    JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_DP_SHIFT;
471 	desc->desc[0].dtc = len >> jzchan->transfer_shift;
472 
473 	return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
474 }
475 
476 static void jz4780_dma_begin(struct jz4780_dma_chan *jzchan)
477 {
478 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
479 	struct virt_dma_desc *vdesc;
480 	unsigned int i;
481 	dma_addr_t desc_phys;
482 
483 	if (!jzchan->desc) {
484 		vdesc = vchan_next_desc(&jzchan->vchan);
485 		if (!vdesc)
486 			return;
487 
488 		list_del(&vdesc->node);
489 
490 		jzchan->desc = to_jz4780_dma_desc(vdesc);
491 		jzchan->curr_hwdesc = 0;
492 
493 		if (jzchan->desc->type == DMA_CYCLIC && vdesc->tx.callback) {
494 			/*
495 			 * The DMA controller doesn't support triggering an
496 			 * interrupt after processing each descriptor, only
497 			 * after processing an entire terminated list of
498 			 * descriptors. For a cyclic DMA setup the list of
499 			 * descriptors is not terminated so we can never get an
500 			 * interrupt.
501 			 *
502 			 * If the user requested a callback for a cyclic DMA
503 			 * setup then we workaround this hardware limitation
504 			 * here by degrading to a set of unlinked descriptors
505 			 * which we will submit in sequence in response to the
506 			 * completion of processing the previous descriptor.
507 			 */
508 			for (i = 0; i < jzchan->desc->count; i++)
509 				jzchan->desc->desc[i].dcm &= ~JZ_DMA_DCM_LINK;
510 		}
511 	} else {
512 		/*
513 		 * There is an existing transfer, therefore this must be one
514 		 * for which we unlinked the descriptors above. Advance to the
515 		 * next one in the list.
516 		 */
517 		jzchan->curr_hwdesc =
518 			(jzchan->curr_hwdesc + 1) % jzchan->desc->count;
519 	}
520 
521 	/* Enable the channel's clock. */
522 	jz4780_dma_chan_enable(jzdma, jzchan->id);
523 
524 	/* Use 4-word descriptors. */
525 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
526 
527 	/* Set transfer type. */
528 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DRT,
529 			      jzchan->transfer_type);
530 
531 	/*
532 	 * Set the transfer count. This is redundant for a descriptor-driven
533 	 * transfer. However, there can be a delay between the transfer start
534 	 * time and when DTCn reg contains the new transfer count. Setting
535 	 * it explicitly ensures residue is computed correctly at all times.
536 	 */
537 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DTC,
538 				jzchan->desc->desc[jzchan->curr_hwdesc].dtc);
539 
540 	/* Write descriptor address and initiate descriptor fetch. */
541 	desc_phys = jzchan->desc->desc_phys +
542 		    (jzchan->curr_hwdesc * sizeof(*jzchan->desc->desc));
543 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DDA, desc_phys);
544 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DDRS, BIT(jzchan->id));
545 
546 	/* Enable the channel. */
547 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS,
548 			      JZ_DMA_DCS_CTE);
549 }
550 
551 static void jz4780_dma_issue_pending(struct dma_chan *chan)
552 {
553 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
554 	unsigned long flags;
555 
556 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
557 
558 	if (vchan_issue_pending(&jzchan->vchan) && !jzchan->desc)
559 		jz4780_dma_begin(jzchan);
560 
561 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
562 }
563 
564 static int jz4780_dma_terminate_all(struct dma_chan *chan)
565 {
566 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
567 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
568 	unsigned long flags;
569 	LIST_HEAD(head);
570 
571 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
572 
573 	/* Clear the DMA status and stop the transfer. */
574 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
575 	if (jzchan->desc) {
576 		vchan_terminate_vdesc(&jzchan->desc->vdesc);
577 		jzchan->desc = NULL;
578 	}
579 
580 	jz4780_dma_chan_disable(jzdma, jzchan->id);
581 
582 	vchan_get_all_descriptors(&jzchan->vchan, &head);
583 
584 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
585 
586 	vchan_dma_desc_free_list(&jzchan->vchan, &head);
587 	return 0;
588 }
589 
590 static void jz4780_dma_synchronize(struct dma_chan *chan)
591 {
592 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
593 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
594 
595 	vchan_synchronize(&jzchan->vchan);
596 	jz4780_dma_chan_disable(jzdma, jzchan->id);
597 }
598 
599 static int jz4780_dma_config(struct dma_chan *chan,
600 	struct dma_slave_config *config)
601 {
602 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
603 
604 	if ((config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
605 	   || (config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES))
606 		return -EINVAL;
607 
608 	/* Copy the reset of the slave configuration, it is used later. */
609 	memcpy(&jzchan->config, config, sizeof(jzchan->config));
610 
611 	return 0;
612 }
613 
614 static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan,
615 	struct jz4780_dma_desc *desc, unsigned int next_sg)
616 {
617 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
618 	unsigned int count = 0;
619 	unsigned int i;
620 
621 	for (i = next_sg; i < desc->count; i++)
622 		count += desc->desc[i].dtc & GENMASK(23, 0);
623 
624 	if (next_sg != 0)
625 		count += jz4780_dma_chn_readl(jzdma, jzchan->id,
626 					 JZ_DMA_REG_DTC);
627 
628 	return count << jzchan->transfer_shift;
629 }
630 
631 static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
632 	dma_cookie_t cookie, struct dma_tx_state *txstate)
633 {
634 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
635 	struct virt_dma_desc *vdesc;
636 	enum dma_status status;
637 	unsigned long flags;
638 	unsigned long residue = 0;
639 
640 	status = dma_cookie_status(chan, cookie, txstate);
641 	if ((status == DMA_COMPLETE) || (txstate == NULL))
642 		return status;
643 
644 	spin_lock_irqsave(&jzchan->vchan.lock, flags);
645 
646 	vdesc = vchan_find_desc(&jzchan->vchan, cookie);
647 	if (vdesc) {
648 		/* On the issued list, so hasn't been processed yet */
649 		residue = jz4780_dma_desc_residue(jzchan,
650 					to_jz4780_dma_desc(vdesc), 0);
651 	} else if (cookie == jzchan->desc->vdesc.tx.cookie) {
652 		residue = jz4780_dma_desc_residue(jzchan, jzchan->desc,
653 					jzchan->curr_hwdesc + 1);
654 	}
655 	dma_set_residue(txstate, residue);
656 
657 	if (vdesc && jzchan->desc && vdesc == &jzchan->desc->vdesc
658 	    && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))
659 		status = DMA_ERROR;
660 
661 	spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
662 	return status;
663 }
664 
665 static bool jz4780_dma_chan_irq(struct jz4780_dma_dev *jzdma,
666 				struct jz4780_dma_chan *jzchan)
667 {
668 	uint32_t dcs;
669 	bool ack = true;
670 
671 	spin_lock(&jzchan->vchan.lock);
672 
673 	dcs = jz4780_dma_chn_readl(jzdma, jzchan->id, JZ_DMA_REG_DCS);
674 	jz4780_dma_chn_writel(jzdma, jzchan->id, JZ_DMA_REG_DCS, 0);
675 
676 	if (dcs & JZ_DMA_DCS_AR) {
677 		dev_warn(&jzchan->vchan.chan.dev->device,
678 			 "address error (DCS=0x%x)\n", dcs);
679 	}
680 
681 	if (dcs & JZ_DMA_DCS_HLT) {
682 		dev_warn(&jzchan->vchan.chan.dev->device,
683 			 "channel halt (DCS=0x%x)\n", dcs);
684 	}
685 
686 	if (jzchan->desc) {
687 		jzchan->desc->status = dcs;
688 
689 		if ((dcs & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT)) == 0) {
690 			if (jzchan->desc->type == DMA_CYCLIC) {
691 				vchan_cyclic_callback(&jzchan->desc->vdesc);
692 
693 				jz4780_dma_begin(jzchan);
694 			} else if (dcs & JZ_DMA_DCS_TT) {
695 				vchan_cookie_complete(&jzchan->desc->vdesc);
696 				jzchan->desc = NULL;
697 
698 				jz4780_dma_begin(jzchan);
699 			} else {
700 				/* False positive - continue the transfer */
701 				ack = false;
702 				jz4780_dma_chn_writel(jzdma, jzchan->id,
703 						      JZ_DMA_REG_DCS,
704 						      JZ_DMA_DCS_CTE);
705 			}
706 		}
707 	} else {
708 		dev_err(&jzchan->vchan.chan.dev->device,
709 			"channel IRQ with no active transfer\n");
710 	}
711 
712 	spin_unlock(&jzchan->vchan.lock);
713 
714 	return ack;
715 }
716 
717 static irqreturn_t jz4780_dma_irq_handler(int irq, void *data)
718 {
719 	struct jz4780_dma_dev *jzdma = data;
720 	unsigned int nb_channels = jzdma->soc_data->nb_channels;
721 	uint32_t pending, dmac;
722 	int i;
723 
724 	pending = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DIRQP);
725 
726 	for_each_set_bit(i, (unsigned long *)&pending, nb_channels) {
727 		if (jz4780_dma_chan_irq(jzdma, &jzdma->chan[i]))
728 			pending &= ~BIT(i);
729 	}
730 
731 	/* Clear halt and address error status of all channels. */
732 	dmac = jz4780_dma_ctrl_readl(jzdma, JZ_DMA_REG_DMAC);
733 	dmac &= ~(JZ_DMA_DMAC_HLT | JZ_DMA_DMAC_AR);
734 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC, dmac);
735 
736 	/* Clear interrupt pending status. */
737 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DIRQP, pending);
738 
739 	return IRQ_HANDLED;
740 }
741 
742 static int jz4780_dma_alloc_chan_resources(struct dma_chan *chan)
743 {
744 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
745 
746 	jzchan->desc_pool = dma_pool_create(dev_name(&chan->dev->device),
747 					    chan->device->dev,
748 					    JZ_DMA_DESC_BLOCK_SIZE,
749 					    PAGE_SIZE, 0);
750 	if (!jzchan->desc_pool) {
751 		dev_err(&chan->dev->device,
752 			"failed to allocate descriptor pool\n");
753 		return -ENOMEM;
754 	}
755 
756 	return 0;
757 }
758 
759 static void jz4780_dma_free_chan_resources(struct dma_chan *chan)
760 {
761 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
762 
763 	vchan_free_chan_resources(&jzchan->vchan);
764 	dma_pool_destroy(jzchan->desc_pool);
765 	jzchan->desc_pool = NULL;
766 }
767 
768 static bool jz4780_dma_filter_fn(struct dma_chan *chan, void *param)
769 {
770 	struct jz4780_dma_chan *jzchan = to_jz4780_dma_chan(chan);
771 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
772 	struct jz4780_dma_filter_data *data = param;
773 
774 	if (jzdma->dma_device.dev->of_node != data->of_node)
775 		return false;
776 
777 	if (data->channel > -1) {
778 		if (data->channel != jzchan->id)
779 			return false;
780 	} else if (jzdma->chan_reserved & BIT(jzchan->id)) {
781 		return false;
782 	}
783 
784 	jzchan->transfer_type = data->transfer_type;
785 
786 	return true;
787 }
788 
789 static struct dma_chan *jz4780_of_dma_xlate(struct of_phandle_args *dma_spec,
790 	struct of_dma *ofdma)
791 {
792 	struct jz4780_dma_dev *jzdma = ofdma->of_dma_data;
793 	dma_cap_mask_t mask = jzdma->dma_device.cap_mask;
794 	struct jz4780_dma_filter_data data;
795 
796 	if (dma_spec->args_count != 2)
797 		return NULL;
798 
799 	data.of_node = ofdma->of_node;
800 	data.transfer_type = dma_spec->args[0];
801 	data.channel = dma_spec->args[1];
802 
803 	if (data.channel > -1) {
804 		if (data.channel >= jzdma->soc_data->nb_channels) {
805 			dev_err(jzdma->dma_device.dev,
806 				"device requested non-existent channel %u\n",
807 				data.channel);
808 			return NULL;
809 		}
810 
811 		/* Can only select a channel marked as reserved. */
812 		if (!(jzdma->chan_reserved & BIT(data.channel))) {
813 			dev_err(jzdma->dma_device.dev,
814 				"device requested unreserved channel %u\n",
815 				data.channel);
816 			return NULL;
817 		}
818 
819 		jzdma->chan[data.channel].transfer_type = data.transfer_type;
820 
821 		return dma_get_slave_channel(
822 			&jzdma->chan[data.channel].vchan.chan);
823 	} else {
824 		return dma_request_channel(mask, jz4780_dma_filter_fn, &data);
825 	}
826 }
827 
828 static int jz4780_dma_probe(struct platform_device *pdev)
829 {
830 	struct device *dev = &pdev->dev;
831 	const struct jz4780_dma_soc_data *soc_data;
832 	struct jz4780_dma_dev *jzdma;
833 	struct jz4780_dma_chan *jzchan;
834 	struct dma_device *dd;
835 	struct resource *res;
836 	int i, ret;
837 
838 	if (!dev->of_node) {
839 		dev_err(dev, "This driver must be probed from devicetree\n");
840 		return -EINVAL;
841 	}
842 
843 	soc_data = device_get_match_data(dev);
844 	if (!soc_data)
845 		return -EINVAL;
846 
847 	jzdma = devm_kzalloc(dev, struct_size(jzdma, chan,
848 			     soc_data->nb_channels), GFP_KERNEL);
849 	if (!jzdma)
850 		return -ENOMEM;
851 
852 	jzdma->soc_data = soc_data;
853 	platform_set_drvdata(pdev, jzdma);
854 
855 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
856 	if (!res) {
857 		dev_err(dev, "failed to get I/O memory\n");
858 		return -EINVAL;
859 	}
860 
861 	jzdma->chn_base = devm_ioremap_resource(dev, res);
862 	if (IS_ERR(jzdma->chn_base))
863 		return PTR_ERR(jzdma->chn_base);
864 
865 	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
866 	if (res) {
867 		jzdma->ctrl_base = devm_ioremap_resource(dev, res);
868 		if (IS_ERR(jzdma->ctrl_base))
869 			return PTR_ERR(jzdma->ctrl_base);
870 	} else if (soc_data->flags & JZ_SOC_DATA_ALLOW_LEGACY_DT) {
871 		/*
872 		 * On JZ4780, if the second memory resource was not supplied,
873 		 * assume we're using an old devicetree, and calculate the
874 		 * offset to the control registers.
875 		 */
876 		jzdma->ctrl_base = jzdma->chn_base + JZ4780_DMA_CTRL_OFFSET;
877 	} else {
878 		dev_err(dev, "failed to get I/O memory\n");
879 		return -EINVAL;
880 	}
881 
882 	ret = platform_get_irq(pdev, 0);
883 	if (ret < 0) {
884 		dev_err(dev, "failed to get IRQ: %d\n", ret);
885 		return ret;
886 	}
887 
888 	jzdma->irq = ret;
889 
890 	ret = request_irq(jzdma->irq, jz4780_dma_irq_handler, 0, dev_name(dev),
891 			  jzdma);
892 	if (ret) {
893 		dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq);
894 		return ret;
895 	}
896 
897 	jzdma->clk = devm_clk_get(dev, NULL);
898 	if (IS_ERR(jzdma->clk)) {
899 		dev_err(dev, "failed to get clock\n");
900 		ret = PTR_ERR(jzdma->clk);
901 		goto err_free_irq;
902 	}
903 
904 	clk_prepare_enable(jzdma->clk);
905 
906 	/* Property is optional, if it doesn't exist the value will remain 0. */
907 	of_property_read_u32_index(dev->of_node, "ingenic,reserved-channels",
908 				   0, &jzdma->chan_reserved);
909 
910 	dd = &jzdma->dma_device;
911 
912 	dma_cap_set(DMA_MEMCPY, dd->cap_mask);
913 	dma_cap_set(DMA_SLAVE, dd->cap_mask);
914 	dma_cap_set(DMA_CYCLIC, dd->cap_mask);
915 
916 	dd->dev = dev;
917 	dd->copy_align = DMAENGINE_ALIGN_4_BYTES;
918 	dd->device_alloc_chan_resources = jz4780_dma_alloc_chan_resources;
919 	dd->device_free_chan_resources = jz4780_dma_free_chan_resources;
920 	dd->device_prep_slave_sg = jz4780_dma_prep_slave_sg;
921 	dd->device_prep_dma_cyclic = jz4780_dma_prep_dma_cyclic;
922 	dd->device_prep_dma_memcpy = jz4780_dma_prep_dma_memcpy;
923 	dd->device_config = jz4780_dma_config;
924 	dd->device_terminate_all = jz4780_dma_terminate_all;
925 	dd->device_synchronize = jz4780_dma_synchronize;
926 	dd->device_tx_status = jz4780_dma_tx_status;
927 	dd->device_issue_pending = jz4780_dma_issue_pending;
928 	dd->src_addr_widths = JZ_DMA_BUSWIDTHS;
929 	dd->dst_addr_widths = JZ_DMA_BUSWIDTHS;
930 	dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
931 	dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
932 
933 	/*
934 	 * Enable DMA controller, mark all channels as not programmable.
935 	 * Also set the FMSC bit - it increases MSC performance, so it makes
936 	 * little sense not to enable it.
937 	 */
938 	jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMAC, JZ_DMA_DMAC_DMAE |
939 			       JZ_DMA_DMAC_FAIC | JZ_DMA_DMAC_FMSC);
940 
941 	if (soc_data->flags & JZ_SOC_DATA_PROGRAMMABLE_DMA)
942 		jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DMACP, 0);
943 
944 	INIT_LIST_HEAD(&dd->channels);
945 
946 	for (i = 0; i < soc_data->nb_channels; i++) {
947 		jzchan = &jzdma->chan[i];
948 		jzchan->id = i;
949 
950 		vchan_init(&jzchan->vchan, dd);
951 		jzchan->vchan.desc_free = jz4780_dma_desc_free;
952 	}
953 
954 	ret = dmaenginem_async_device_register(dd);
955 	if (ret) {
956 		dev_err(dev, "failed to register device\n");
957 		goto err_disable_clk;
958 	}
959 
960 	/* Register with OF DMA helpers. */
961 	ret = of_dma_controller_register(dev->of_node, jz4780_of_dma_xlate,
962 					 jzdma);
963 	if (ret) {
964 		dev_err(dev, "failed to register OF DMA controller\n");
965 		goto err_disable_clk;
966 	}
967 
968 	dev_info(dev, "JZ4780 DMA controller initialised\n");
969 	return 0;
970 
971 err_disable_clk:
972 	clk_disable_unprepare(jzdma->clk);
973 
974 err_free_irq:
975 	free_irq(jzdma->irq, jzdma);
976 	return ret;
977 }
978 
979 static int jz4780_dma_remove(struct platform_device *pdev)
980 {
981 	struct jz4780_dma_dev *jzdma = platform_get_drvdata(pdev);
982 	int i;
983 
984 	of_dma_controller_free(pdev->dev.of_node);
985 
986 	free_irq(jzdma->irq, jzdma);
987 
988 	for (i = 0; i < jzdma->soc_data->nb_channels; i++)
989 		tasklet_kill(&jzdma->chan[i].vchan.task);
990 
991 	return 0;
992 }
993 
994 static const struct jz4780_dma_soc_data jz4740_dma_soc_data = {
995 	.nb_channels = 6,
996 	.transfer_ord_max = 5,
997 };
998 
999 static const struct jz4780_dma_soc_data jz4725b_dma_soc_data = {
1000 	.nb_channels = 6,
1001 	.transfer_ord_max = 5,
1002 	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
1003 };
1004 
1005 static const struct jz4780_dma_soc_data jz4770_dma_soc_data = {
1006 	.nb_channels = 6,
1007 	.transfer_ord_max = 6,
1008 	.flags = JZ_SOC_DATA_PER_CHAN_PM,
1009 };
1010 
1011 static const struct jz4780_dma_soc_data jz4780_dma_soc_data = {
1012 	.nb_channels = 32,
1013 	.transfer_ord_max = 7,
1014 	.flags = JZ_SOC_DATA_ALLOW_LEGACY_DT | JZ_SOC_DATA_PROGRAMMABLE_DMA,
1015 };
1016 
1017 static const struct of_device_id jz4780_dma_dt_match[] = {
1018 	{ .compatible = "ingenic,jz4740-dma", .data = &jz4740_dma_soc_data },
1019 	{ .compatible = "ingenic,jz4725b-dma", .data = &jz4725b_dma_soc_data },
1020 	{ .compatible = "ingenic,jz4770-dma", .data = &jz4770_dma_soc_data },
1021 	{ .compatible = "ingenic,jz4780-dma", .data = &jz4780_dma_soc_data },
1022 	{},
1023 };
1024 MODULE_DEVICE_TABLE(of, jz4780_dma_dt_match);
1025 
1026 static struct platform_driver jz4780_dma_driver = {
1027 	.probe		= jz4780_dma_probe,
1028 	.remove		= jz4780_dma_remove,
1029 	.driver	= {
1030 		.name	= "jz4780-dma",
1031 		.of_match_table = of_match_ptr(jz4780_dma_dt_match),
1032 	},
1033 };
1034 
1035 static int __init jz4780_dma_init(void)
1036 {
1037 	return platform_driver_register(&jz4780_dma_driver);
1038 }
1039 subsys_initcall(jz4780_dma_init);
1040 
1041 static void __exit jz4780_dma_exit(void)
1042 {
1043 	platform_driver_unregister(&jz4780_dma_driver);
1044 }
1045 module_exit(jz4780_dma_exit);
1046 
1047 MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
1048 MODULE_DESCRIPTION("Ingenic JZ4780 DMA controller driver");
1049 MODULE_LICENSE("GPL");
1050