xref: /openbmc/linux/drivers/dma/sprd-dma.c (revision 217188d9)
1 /*
2  * Copyright (C) 2017 Spreadtrum Communications Inc.
3  *
4  * SPDX-License-Identifier: GPL-2.0
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/dma-mapping.h>
9 #include <linux/dma/sprd-dma.h>
10 #include <linux/errno.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/io.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_dma.h>
18 #include <linux/of_device.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/slab.h>
21 
22 #include "virt-dma.h"
23 
24 #define SPRD_DMA_CHN_REG_OFFSET		0x1000
25 #define SPRD_DMA_CHN_REG_LENGTH		0x40
26 #define SPRD_DMA_MEMCPY_MIN_SIZE	64
27 
28 /* DMA global registers definition */
29 #define SPRD_DMA_GLB_PAUSE		0x0
30 #define SPRD_DMA_GLB_FRAG_WAIT		0x4
31 #define SPRD_DMA_GLB_REQ_PEND0_EN	0x8
32 #define SPRD_DMA_GLB_REQ_PEND1_EN	0xc
33 #define SPRD_DMA_GLB_INT_RAW_STS	0x10
34 #define SPRD_DMA_GLB_INT_MSK_STS	0x14
35 #define SPRD_DMA_GLB_REQ_STS		0x18
36 #define SPRD_DMA_GLB_CHN_EN_STS		0x1c
37 #define SPRD_DMA_GLB_DEBUG_STS		0x20
38 #define SPRD_DMA_GLB_ARB_SEL_STS	0x24
39 #define SPRD_DMA_GLB_REQ_UID(uid)	(0x4 * ((uid) - 1))
40 #define SPRD_DMA_GLB_REQ_UID_OFFSET	0x2000
41 
42 /* DMA channel registers definition */
43 #define SPRD_DMA_CHN_PAUSE		0x0
44 #define SPRD_DMA_CHN_REQ		0x4
45 #define SPRD_DMA_CHN_CFG		0x8
46 #define SPRD_DMA_CHN_INTC		0xc
47 #define SPRD_DMA_CHN_SRC_ADDR		0x10
48 #define SPRD_DMA_CHN_DES_ADDR		0x14
49 #define SPRD_DMA_CHN_FRG_LEN		0x18
50 #define SPRD_DMA_CHN_BLK_LEN		0x1c
51 #define SPRD_DMA_CHN_TRSC_LEN		0x20
52 #define SPRD_DMA_CHN_TRSF_STEP		0x24
53 #define SPRD_DMA_CHN_WARP_PTR		0x28
54 #define SPRD_DMA_CHN_WARP_TO		0x2c
55 #define SPRD_DMA_CHN_LLIST_PTR		0x30
56 #define SPRD_DMA_CHN_FRAG_STEP		0x34
57 #define SPRD_DMA_CHN_SRC_BLK_STEP	0x38
58 #define SPRD_DMA_CHN_DES_BLK_STEP	0x3c
59 
60 /* SPRD_DMA_CHN_INTC register definition */
61 #define SPRD_DMA_INT_MASK		GENMASK(4, 0)
62 #define SPRD_DMA_INT_CLR_OFFSET		24
63 #define SPRD_DMA_FRAG_INT_EN		BIT(0)
64 #define SPRD_DMA_BLK_INT_EN		BIT(1)
65 #define SPRD_DMA_TRANS_INT_EN		BIT(2)
66 #define SPRD_DMA_LIST_INT_EN		BIT(3)
67 #define SPRD_DMA_CFG_ERR_INT_EN		BIT(4)
68 
69 /* SPRD_DMA_CHN_CFG register definition */
70 #define SPRD_DMA_CHN_EN			BIT(0)
71 #define SPRD_DMA_WAIT_BDONE_OFFSET	24
72 #define SPRD_DMA_DONOT_WAIT_BDONE	1
73 
74 /* SPRD_DMA_CHN_REQ register definition */
75 #define SPRD_DMA_REQ_EN			BIT(0)
76 
77 /* SPRD_DMA_CHN_PAUSE register definition */
78 #define SPRD_DMA_PAUSE_EN		BIT(0)
79 #define SPRD_DMA_PAUSE_STS		BIT(2)
80 #define SPRD_DMA_PAUSE_CNT		0x2000
81 
82 /* DMA_CHN_WARP_* register definition */
83 #define SPRD_DMA_HIGH_ADDR_MASK		GENMASK(31, 28)
84 #define SPRD_DMA_LOW_ADDR_MASK		GENMASK(31, 0)
85 #define SPRD_DMA_HIGH_ADDR_OFFSET	4
86 
87 /* SPRD_DMA_CHN_INTC register definition */
88 #define SPRD_DMA_FRAG_INT_STS		BIT(16)
89 #define SPRD_DMA_BLK_INT_STS		BIT(17)
90 #define SPRD_DMA_TRSC_INT_STS		BIT(18)
91 #define SPRD_DMA_LIST_INT_STS		BIT(19)
92 #define SPRD_DMA_CFGERR_INT_STS		BIT(20)
93 #define SPRD_DMA_CHN_INT_STS					\
94 	(SPRD_DMA_FRAG_INT_STS | SPRD_DMA_BLK_INT_STS |		\
95 	 SPRD_DMA_TRSC_INT_STS | SPRD_DMA_LIST_INT_STS |	\
96 	 SPRD_DMA_CFGERR_INT_STS)
97 
98 /* SPRD_DMA_CHN_FRG_LEN register definition */
99 #define SPRD_DMA_SRC_DATAWIDTH_OFFSET	30
100 #define SPRD_DMA_DES_DATAWIDTH_OFFSET	28
101 #define SPRD_DMA_SWT_MODE_OFFSET	26
102 #define SPRD_DMA_REQ_MODE_OFFSET	24
103 #define SPRD_DMA_REQ_MODE_MASK		GENMASK(1, 0)
104 #define SPRD_DMA_FIX_SEL_OFFSET		21
105 #define SPRD_DMA_FIX_EN_OFFSET		20
106 #define SPRD_DMA_LLIST_END_OFFSET	19
107 #define SPRD_DMA_FRG_LEN_MASK		GENMASK(16, 0)
108 
109 /* SPRD_DMA_CHN_BLK_LEN register definition */
110 #define SPRD_DMA_BLK_LEN_MASK		GENMASK(16, 0)
111 
112 /* SPRD_DMA_CHN_TRSC_LEN register definition */
113 #define SPRD_DMA_TRSC_LEN_MASK		GENMASK(27, 0)
114 
115 /* SPRD_DMA_CHN_TRSF_STEP register definition */
116 #define SPRD_DMA_DEST_TRSF_STEP_OFFSET	16
117 #define SPRD_DMA_SRC_TRSF_STEP_OFFSET	0
118 #define SPRD_DMA_TRSF_STEP_MASK		GENMASK(15, 0)
119 
120 /* define the DMA transfer step type */
121 #define SPRD_DMA_NONE_STEP		0
122 #define SPRD_DMA_BYTE_STEP		1
123 #define SPRD_DMA_SHORT_STEP		2
124 #define SPRD_DMA_WORD_STEP		4
125 #define SPRD_DMA_DWORD_STEP		8
126 
127 #define SPRD_DMA_SOFTWARE_UID		0
128 
129 /* dma data width values */
130 enum sprd_dma_datawidth {
131 	SPRD_DMA_DATAWIDTH_1_BYTE,
132 	SPRD_DMA_DATAWIDTH_2_BYTES,
133 	SPRD_DMA_DATAWIDTH_4_BYTES,
134 	SPRD_DMA_DATAWIDTH_8_BYTES,
135 };
136 
137 /* dma channel hardware configuration */
138 struct sprd_dma_chn_hw {
139 	u32 pause;
140 	u32 req;
141 	u32 cfg;
142 	u32 intc;
143 	u32 src_addr;
144 	u32 des_addr;
145 	u32 frg_len;
146 	u32 blk_len;
147 	u32 trsc_len;
148 	u32 trsf_step;
149 	u32 wrap_ptr;
150 	u32 wrap_to;
151 	u32 llist_ptr;
152 	u32 frg_step;
153 	u32 src_blk_step;
154 	u32 des_blk_step;
155 };
156 
157 /* dma request description */
158 struct sprd_dma_desc {
159 	struct virt_dma_desc	vd;
160 	struct sprd_dma_chn_hw	chn_hw;
161 };
162 
163 /* dma channel description */
164 struct sprd_dma_chn {
165 	struct virt_dma_chan	vc;
166 	void __iomem		*chn_base;
167 	struct dma_slave_config	slave_cfg;
168 	u32			chn_num;
169 	u32			dev_id;
170 	struct sprd_dma_desc	*cur_desc;
171 };
172 
173 /* SPRD dma device */
174 struct sprd_dma_dev {
175 	struct dma_device	dma_dev;
176 	void __iomem		*glb_base;
177 	struct clk		*clk;
178 	struct clk		*ashb_clk;
179 	int			irq;
180 	u32			total_chns;
181 	struct sprd_dma_chn	channels[0];
182 };
183 
184 static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param);
185 static struct of_dma_filter_info sprd_dma_info = {
186 	.filter_fn = sprd_dma_filter_fn,
187 };
188 
189 static inline struct sprd_dma_chn *to_sprd_dma_chan(struct dma_chan *c)
190 {
191 	return container_of(c, struct sprd_dma_chn, vc.chan);
192 }
193 
194 static inline struct sprd_dma_dev *to_sprd_dma_dev(struct dma_chan *c)
195 {
196 	struct sprd_dma_chn *schan = to_sprd_dma_chan(c);
197 
198 	return container_of(schan, struct sprd_dma_dev, channels[c->chan_id]);
199 }
200 
201 static inline struct sprd_dma_desc *to_sprd_dma_desc(struct virt_dma_desc *vd)
202 {
203 	return container_of(vd, struct sprd_dma_desc, vd);
204 }
205 
206 static void sprd_dma_chn_update(struct sprd_dma_chn *schan, u32 reg,
207 				u32 mask, u32 val)
208 {
209 	u32 orig = readl(schan->chn_base + reg);
210 	u32 tmp;
211 
212 	tmp = (orig & ~mask) | val;
213 	writel(tmp, schan->chn_base + reg);
214 }
215 
216 static int sprd_dma_enable(struct sprd_dma_dev *sdev)
217 {
218 	int ret;
219 
220 	ret = clk_prepare_enable(sdev->clk);
221 	if (ret)
222 		return ret;
223 
224 	/*
225 	 * The ashb_clk is optional and only for AGCP DMA controller, so we
226 	 * need add one condition to check if the ashb_clk need enable.
227 	 */
228 	if (!IS_ERR(sdev->ashb_clk))
229 		ret = clk_prepare_enable(sdev->ashb_clk);
230 
231 	return ret;
232 }
233 
234 static void sprd_dma_disable(struct sprd_dma_dev *sdev)
235 {
236 	clk_disable_unprepare(sdev->clk);
237 
238 	/*
239 	 * Need to check if we need disable the optional ashb_clk for AGCP DMA.
240 	 */
241 	if (!IS_ERR(sdev->ashb_clk))
242 		clk_disable_unprepare(sdev->ashb_clk);
243 }
244 
245 static void sprd_dma_set_uid(struct sprd_dma_chn *schan)
246 {
247 	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
248 	u32 dev_id = schan->dev_id;
249 
250 	if (dev_id != SPRD_DMA_SOFTWARE_UID) {
251 		u32 uid_offset = SPRD_DMA_GLB_REQ_UID_OFFSET +
252 				 SPRD_DMA_GLB_REQ_UID(dev_id);
253 
254 		writel(schan->chn_num + 1, sdev->glb_base + uid_offset);
255 	}
256 }
257 
258 static void sprd_dma_unset_uid(struct sprd_dma_chn *schan)
259 {
260 	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
261 	u32 dev_id = schan->dev_id;
262 
263 	if (dev_id != SPRD_DMA_SOFTWARE_UID) {
264 		u32 uid_offset = SPRD_DMA_GLB_REQ_UID_OFFSET +
265 				 SPRD_DMA_GLB_REQ_UID(dev_id);
266 
267 		writel(0, sdev->glb_base + uid_offset);
268 	}
269 }
270 
271 static void sprd_dma_clear_int(struct sprd_dma_chn *schan)
272 {
273 	sprd_dma_chn_update(schan, SPRD_DMA_CHN_INTC,
274 			    SPRD_DMA_INT_MASK << SPRD_DMA_INT_CLR_OFFSET,
275 			    SPRD_DMA_INT_MASK << SPRD_DMA_INT_CLR_OFFSET);
276 }
277 
278 static void sprd_dma_enable_chn(struct sprd_dma_chn *schan)
279 {
280 	sprd_dma_chn_update(schan, SPRD_DMA_CHN_CFG, SPRD_DMA_CHN_EN,
281 			    SPRD_DMA_CHN_EN);
282 }
283 
284 static void sprd_dma_disable_chn(struct sprd_dma_chn *schan)
285 {
286 	sprd_dma_chn_update(schan, SPRD_DMA_CHN_CFG, SPRD_DMA_CHN_EN, 0);
287 }
288 
289 static void sprd_dma_soft_request(struct sprd_dma_chn *schan)
290 {
291 	sprd_dma_chn_update(schan, SPRD_DMA_CHN_REQ, SPRD_DMA_REQ_EN,
292 			    SPRD_DMA_REQ_EN);
293 }
294 
295 static void sprd_dma_pause_resume(struct sprd_dma_chn *schan, bool enable)
296 {
297 	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
298 	u32 pause, timeout = SPRD_DMA_PAUSE_CNT;
299 
300 	if (enable) {
301 		sprd_dma_chn_update(schan, SPRD_DMA_CHN_PAUSE,
302 				    SPRD_DMA_PAUSE_EN, SPRD_DMA_PAUSE_EN);
303 
304 		do {
305 			pause = readl(schan->chn_base + SPRD_DMA_CHN_PAUSE);
306 			if (pause & SPRD_DMA_PAUSE_STS)
307 				break;
308 
309 			cpu_relax();
310 		} while (--timeout > 0);
311 
312 		if (!timeout)
313 			dev_warn(sdev->dma_dev.dev,
314 				 "pause dma controller timeout\n");
315 	} else {
316 		sprd_dma_chn_update(schan, SPRD_DMA_CHN_PAUSE,
317 				    SPRD_DMA_PAUSE_EN, 0);
318 	}
319 }
320 
321 static void sprd_dma_stop_and_disable(struct sprd_dma_chn *schan)
322 {
323 	u32 cfg = readl(schan->chn_base + SPRD_DMA_CHN_CFG);
324 
325 	if (!(cfg & SPRD_DMA_CHN_EN))
326 		return;
327 
328 	sprd_dma_pause_resume(schan, true);
329 	sprd_dma_disable_chn(schan);
330 }
331 
332 static unsigned long sprd_dma_get_dst_addr(struct sprd_dma_chn *schan)
333 {
334 	unsigned long addr, addr_high;
335 
336 	addr = readl(schan->chn_base + SPRD_DMA_CHN_DES_ADDR);
337 	addr_high = readl(schan->chn_base + SPRD_DMA_CHN_WARP_TO) &
338 		    SPRD_DMA_HIGH_ADDR_MASK;
339 
340 	return addr | (addr_high << SPRD_DMA_HIGH_ADDR_OFFSET);
341 }
342 
343 static enum sprd_dma_int_type sprd_dma_get_int_type(struct sprd_dma_chn *schan)
344 {
345 	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
346 	u32 intc_sts = readl(schan->chn_base + SPRD_DMA_CHN_INTC) &
347 		       SPRD_DMA_CHN_INT_STS;
348 
349 	switch (intc_sts) {
350 	case SPRD_DMA_CFGERR_INT_STS:
351 		return SPRD_DMA_CFGERR_INT;
352 
353 	case SPRD_DMA_LIST_INT_STS:
354 		return SPRD_DMA_LIST_INT;
355 
356 	case SPRD_DMA_TRSC_INT_STS:
357 		return SPRD_DMA_TRANS_INT;
358 
359 	case SPRD_DMA_BLK_INT_STS:
360 		return SPRD_DMA_BLK_INT;
361 
362 	case SPRD_DMA_FRAG_INT_STS:
363 		return SPRD_DMA_FRAG_INT;
364 
365 	default:
366 		dev_warn(sdev->dma_dev.dev, "incorrect dma interrupt type\n");
367 		return SPRD_DMA_NO_INT;
368 	}
369 }
370 
371 static enum sprd_dma_req_mode sprd_dma_get_req_type(struct sprd_dma_chn *schan)
372 {
373 	u32 frag_reg = readl(schan->chn_base + SPRD_DMA_CHN_FRG_LEN);
374 
375 	return (frag_reg >> SPRD_DMA_REQ_MODE_OFFSET) & SPRD_DMA_REQ_MODE_MASK;
376 }
377 
378 static void sprd_dma_set_chn_config(struct sprd_dma_chn *schan,
379 				    struct sprd_dma_desc *sdesc)
380 {
381 	struct sprd_dma_chn_hw *cfg = &sdesc->chn_hw;
382 
383 	writel(cfg->pause, schan->chn_base + SPRD_DMA_CHN_PAUSE);
384 	writel(cfg->cfg, schan->chn_base + SPRD_DMA_CHN_CFG);
385 	writel(cfg->intc, schan->chn_base + SPRD_DMA_CHN_INTC);
386 	writel(cfg->src_addr, schan->chn_base + SPRD_DMA_CHN_SRC_ADDR);
387 	writel(cfg->des_addr, schan->chn_base + SPRD_DMA_CHN_DES_ADDR);
388 	writel(cfg->frg_len, schan->chn_base + SPRD_DMA_CHN_FRG_LEN);
389 	writel(cfg->blk_len, schan->chn_base + SPRD_DMA_CHN_BLK_LEN);
390 	writel(cfg->trsc_len, schan->chn_base + SPRD_DMA_CHN_TRSC_LEN);
391 	writel(cfg->trsf_step, schan->chn_base + SPRD_DMA_CHN_TRSF_STEP);
392 	writel(cfg->wrap_ptr, schan->chn_base + SPRD_DMA_CHN_WARP_PTR);
393 	writel(cfg->wrap_to, schan->chn_base + SPRD_DMA_CHN_WARP_TO);
394 	writel(cfg->llist_ptr, schan->chn_base + SPRD_DMA_CHN_LLIST_PTR);
395 	writel(cfg->frg_step, schan->chn_base + SPRD_DMA_CHN_FRAG_STEP);
396 	writel(cfg->src_blk_step, schan->chn_base + SPRD_DMA_CHN_SRC_BLK_STEP);
397 	writel(cfg->des_blk_step, schan->chn_base + SPRD_DMA_CHN_DES_BLK_STEP);
398 	writel(cfg->req, schan->chn_base + SPRD_DMA_CHN_REQ);
399 }
400 
401 static void sprd_dma_start(struct sprd_dma_chn *schan)
402 {
403 	struct virt_dma_desc *vd = vchan_next_desc(&schan->vc);
404 
405 	if (!vd)
406 		return;
407 
408 	list_del(&vd->node);
409 	schan->cur_desc = to_sprd_dma_desc(vd);
410 
411 	/*
412 	 * Copy the DMA configuration from DMA descriptor to this hardware
413 	 * channel.
414 	 */
415 	sprd_dma_set_chn_config(schan, schan->cur_desc);
416 	sprd_dma_set_uid(schan);
417 	sprd_dma_enable_chn(schan);
418 
419 	if (schan->dev_id == SPRD_DMA_SOFTWARE_UID)
420 		sprd_dma_soft_request(schan);
421 }
422 
423 static void sprd_dma_stop(struct sprd_dma_chn *schan)
424 {
425 	sprd_dma_stop_and_disable(schan);
426 	sprd_dma_unset_uid(schan);
427 	sprd_dma_clear_int(schan);
428 }
429 
430 static bool sprd_dma_check_trans_done(struct sprd_dma_desc *sdesc,
431 				      enum sprd_dma_int_type int_type,
432 				      enum sprd_dma_req_mode req_mode)
433 {
434 	if (int_type == SPRD_DMA_NO_INT)
435 		return false;
436 
437 	if (int_type >= req_mode + 1)
438 		return true;
439 	else
440 		return false;
441 }
442 
443 static irqreturn_t dma_irq_handle(int irq, void *dev_id)
444 {
445 	struct sprd_dma_dev *sdev = (struct sprd_dma_dev *)dev_id;
446 	u32 irq_status = readl(sdev->glb_base + SPRD_DMA_GLB_INT_MSK_STS);
447 	struct sprd_dma_chn *schan;
448 	struct sprd_dma_desc *sdesc;
449 	enum sprd_dma_req_mode req_type;
450 	enum sprd_dma_int_type int_type;
451 	bool trans_done = false;
452 	u32 i;
453 
454 	while (irq_status) {
455 		i = __ffs(irq_status);
456 		irq_status &= (irq_status - 1);
457 		schan = &sdev->channels[i];
458 
459 		spin_lock(&schan->vc.lock);
460 		int_type = sprd_dma_get_int_type(schan);
461 		req_type = sprd_dma_get_req_type(schan);
462 		sprd_dma_clear_int(schan);
463 
464 		sdesc = schan->cur_desc;
465 
466 		/* Check if the dma request descriptor is done. */
467 		trans_done = sprd_dma_check_trans_done(sdesc, int_type,
468 						       req_type);
469 		if (trans_done == true) {
470 			vchan_cookie_complete(&sdesc->vd);
471 			schan->cur_desc = NULL;
472 			sprd_dma_start(schan);
473 		}
474 		spin_unlock(&schan->vc.lock);
475 	}
476 
477 	return IRQ_HANDLED;
478 }
479 
480 static int sprd_dma_alloc_chan_resources(struct dma_chan *chan)
481 {
482 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
483 	int ret;
484 
485 	ret = pm_runtime_get_sync(chan->device->dev);
486 	if (ret < 0)
487 		return ret;
488 
489 	schan->dev_id = SPRD_DMA_SOFTWARE_UID;
490 	return 0;
491 }
492 
493 static void sprd_dma_free_chan_resources(struct dma_chan *chan)
494 {
495 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
496 	unsigned long flags;
497 
498 	spin_lock_irqsave(&schan->vc.lock, flags);
499 	sprd_dma_stop(schan);
500 	spin_unlock_irqrestore(&schan->vc.lock, flags);
501 
502 	vchan_free_chan_resources(&schan->vc);
503 	pm_runtime_put(chan->device->dev);
504 }
505 
506 static enum dma_status sprd_dma_tx_status(struct dma_chan *chan,
507 					  dma_cookie_t cookie,
508 					  struct dma_tx_state *txstate)
509 {
510 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
511 	struct virt_dma_desc *vd;
512 	unsigned long flags;
513 	enum dma_status ret;
514 	u32 pos;
515 
516 	ret = dma_cookie_status(chan, cookie, txstate);
517 	if (ret == DMA_COMPLETE || !txstate)
518 		return ret;
519 
520 	spin_lock_irqsave(&schan->vc.lock, flags);
521 	vd = vchan_find_desc(&schan->vc, cookie);
522 	if (vd) {
523 		struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
524 		struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
525 
526 		if (hw->trsc_len > 0)
527 			pos = hw->trsc_len;
528 		else if (hw->blk_len > 0)
529 			pos = hw->blk_len;
530 		else if (hw->frg_len > 0)
531 			pos = hw->frg_len;
532 		else
533 			pos = 0;
534 	} else if (schan->cur_desc && schan->cur_desc->vd.tx.cookie == cookie) {
535 		pos = sprd_dma_get_dst_addr(schan);
536 	} else {
537 		pos = 0;
538 	}
539 	spin_unlock_irqrestore(&schan->vc.lock, flags);
540 
541 	dma_set_residue(txstate, pos);
542 	return ret;
543 }
544 
545 static void sprd_dma_issue_pending(struct dma_chan *chan)
546 {
547 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
548 	unsigned long flags;
549 
550 	spin_lock_irqsave(&schan->vc.lock, flags);
551 	if (vchan_issue_pending(&schan->vc) && !schan->cur_desc)
552 		sprd_dma_start(schan);
553 	spin_unlock_irqrestore(&schan->vc.lock, flags);
554 }
555 
556 static int sprd_dma_get_datawidth(enum dma_slave_buswidth buswidth)
557 {
558 	switch (buswidth) {
559 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
560 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
561 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
562 	case DMA_SLAVE_BUSWIDTH_8_BYTES:
563 		return ffs(buswidth) - 1;
564 
565 	default:
566 		return -EINVAL;
567 	}
568 }
569 
570 static int sprd_dma_get_step(enum dma_slave_buswidth buswidth)
571 {
572 	switch (buswidth) {
573 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
574 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
575 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
576 	case DMA_SLAVE_BUSWIDTH_8_BYTES:
577 		return buswidth;
578 
579 	default:
580 		return -EINVAL;
581 	}
582 }
583 
584 static int sprd_dma_fill_desc(struct dma_chan *chan,
585 			      struct sprd_dma_desc *sdesc,
586 			      dma_addr_t src, dma_addr_t dst, u32 len,
587 			      enum dma_transfer_direction dir,
588 			      unsigned long flags,
589 			      struct dma_slave_config *slave_cfg)
590 {
591 	struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
592 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
593 	struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
594 	u32 req_mode = (flags >> SPRD_DMA_REQ_SHIFT) & SPRD_DMA_REQ_MODE_MASK;
595 	u32 int_mode = flags & SPRD_DMA_INT_MASK;
596 	int src_datawidth, dst_datawidth, src_step, dst_step;
597 	u32 temp, fix_mode = 0, fix_en = 0;
598 
599 	if (dir == DMA_MEM_TO_DEV) {
600 		src_step = sprd_dma_get_step(slave_cfg->src_addr_width);
601 		if (src_step < 0) {
602 			dev_err(sdev->dma_dev.dev, "invalid source step\n");
603 			return src_step;
604 		}
605 		dst_step = SPRD_DMA_NONE_STEP;
606 	} else {
607 		dst_step = sprd_dma_get_step(slave_cfg->dst_addr_width);
608 		if (dst_step < 0) {
609 			dev_err(sdev->dma_dev.dev, "invalid destination step\n");
610 			return dst_step;
611 		}
612 		src_step = SPRD_DMA_NONE_STEP;
613 	}
614 
615 	src_datawidth = sprd_dma_get_datawidth(slave_cfg->src_addr_width);
616 	if (src_datawidth < 0) {
617 		dev_err(sdev->dma_dev.dev, "invalid source datawidth\n");
618 		return src_datawidth;
619 	}
620 
621 	dst_datawidth = sprd_dma_get_datawidth(slave_cfg->dst_addr_width);
622 	if (dst_datawidth < 0) {
623 		dev_err(sdev->dma_dev.dev, "invalid destination datawidth\n");
624 		return dst_datawidth;
625 	}
626 
627 	if (slave_cfg->slave_id)
628 		schan->dev_id = slave_cfg->slave_id;
629 
630 	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
631 
632 	/*
633 	 * wrap_ptr and wrap_to will save the high 4 bits source address and
634 	 * destination address.
635 	 */
636 	hw->wrap_ptr = (src >> SPRD_DMA_HIGH_ADDR_OFFSET) & SPRD_DMA_HIGH_ADDR_MASK;
637 	hw->wrap_to = (dst >> SPRD_DMA_HIGH_ADDR_OFFSET) & SPRD_DMA_HIGH_ADDR_MASK;
638 	hw->src_addr = src & SPRD_DMA_LOW_ADDR_MASK;
639 	hw->des_addr = dst & SPRD_DMA_LOW_ADDR_MASK;
640 
641 	/*
642 	 * If the src step and dst step both are 0 or both are not 0, that means
643 	 * we can not enable the fix mode. If one is 0 and another one is not,
644 	 * we can enable the fix mode.
645 	 */
646 	if ((src_step != 0 && dst_step != 0) || (src_step | dst_step) == 0) {
647 		fix_en = 0;
648 	} else {
649 		fix_en = 1;
650 		if (src_step)
651 			fix_mode = 1;
652 		else
653 			fix_mode = 0;
654 	}
655 
656 	hw->intc = int_mode | SPRD_DMA_CFG_ERR_INT_EN;
657 
658 	temp = src_datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET;
659 	temp |= dst_datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET;
660 	temp |= req_mode << SPRD_DMA_REQ_MODE_OFFSET;
661 	temp |= fix_mode << SPRD_DMA_FIX_SEL_OFFSET;
662 	temp |= fix_en << SPRD_DMA_FIX_EN_OFFSET;
663 	temp |= slave_cfg->src_maxburst & SPRD_DMA_FRG_LEN_MASK;
664 	hw->frg_len = temp;
665 
666 	hw->blk_len = len & SPRD_DMA_BLK_LEN_MASK;
667 	hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;
668 
669 	temp = (dst_step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_DEST_TRSF_STEP_OFFSET;
670 	temp |= (src_step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_SRC_TRSF_STEP_OFFSET;
671 	hw->trsf_step = temp;
672 
673 	hw->frg_step = 0;
674 	hw->src_blk_step = 0;
675 	hw->des_blk_step = 0;
676 	return 0;
677 }
678 
679 static struct dma_async_tx_descriptor *
680 sprd_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
681 			 size_t len, unsigned long flags)
682 {
683 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
684 	struct sprd_dma_desc *sdesc;
685 	struct sprd_dma_chn_hw *hw;
686 	enum sprd_dma_datawidth datawidth;
687 	u32 step, temp;
688 
689 	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
690 	if (!sdesc)
691 		return NULL;
692 
693 	hw = &sdesc->chn_hw;
694 
695 	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE_OFFSET;
696 	hw->intc = SPRD_DMA_TRANS_INT | SPRD_DMA_CFG_ERR_INT_EN;
697 	hw->src_addr = src & SPRD_DMA_LOW_ADDR_MASK;
698 	hw->des_addr = dest & SPRD_DMA_LOW_ADDR_MASK;
699 	hw->wrap_ptr = (src >> SPRD_DMA_HIGH_ADDR_OFFSET) &
700 		SPRD_DMA_HIGH_ADDR_MASK;
701 	hw->wrap_to = (dest >> SPRD_DMA_HIGH_ADDR_OFFSET) &
702 		SPRD_DMA_HIGH_ADDR_MASK;
703 
704 	if (IS_ALIGNED(len, 8)) {
705 		datawidth = SPRD_DMA_DATAWIDTH_8_BYTES;
706 		step = SPRD_DMA_DWORD_STEP;
707 	} else if (IS_ALIGNED(len, 4)) {
708 		datawidth = SPRD_DMA_DATAWIDTH_4_BYTES;
709 		step = SPRD_DMA_WORD_STEP;
710 	} else if (IS_ALIGNED(len, 2)) {
711 		datawidth = SPRD_DMA_DATAWIDTH_2_BYTES;
712 		step = SPRD_DMA_SHORT_STEP;
713 	} else {
714 		datawidth = SPRD_DMA_DATAWIDTH_1_BYTE;
715 		step = SPRD_DMA_BYTE_STEP;
716 	}
717 
718 	temp = datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET;
719 	temp |= datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET;
720 	temp |= SPRD_DMA_TRANS_REQ << SPRD_DMA_REQ_MODE_OFFSET;
721 	temp |= len & SPRD_DMA_FRG_LEN_MASK;
722 	hw->frg_len = temp;
723 
724 	hw->blk_len = len & SPRD_DMA_BLK_LEN_MASK;
725 	hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;
726 
727 	temp = (step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_DEST_TRSF_STEP_OFFSET;
728 	temp |= (step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_SRC_TRSF_STEP_OFFSET;
729 	hw->trsf_step = temp;
730 
731 	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
732 }
733 
734 static struct dma_async_tx_descriptor *
735 sprd_dma_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
736 		       unsigned int sglen, enum dma_transfer_direction dir,
737 		       unsigned long flags, void *context)
738 {
739 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
740 	struct dma_slave_config *slave_cfg = &schan->slave_cfg;
741 	dma_addr_t src = 0, dst = 0;
742 	struct sprd_dma_desc *sdesc;
743 	struct scatterlist *sg;
744 	u32 len = 0;
745 	int ret, i;
746 
747 	/* TODO: now we only support one sg for each DMA configuration. */
748 	if (!is_slave_direction(dir) || sglen > 1)
749 		return NULL;
750 
751 	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
752 	if (!sdesc)
753 		return NULL;
754 
755 	for_each_sg(sgl, sg, sglen, i) {
756 		len = sg_dma_len(sg);
757 
758 		if (dir == DMA_MEM_TO_DEV) {
759 			src = sg_dma_address(sg);
760 			dst = slave_cfg->dst_addr;
761 		} else {
762 			src = slave_cfg->src_addr;
763 			dst = sg_dma_address(sg);
764 		}
765 	}
766 
767 	ret = sprd_dma_fill_desc(chan, sdesc, src, dst, len, dir, flags,
768 				 slave_cfg);
769 	if (ret) {
770 		kfree(sdesc);
771 		return NULL;
772 	}
773 
774 	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
775 }
776 
777 static int sprd_dma_slave_config(struct dma_chan *chan,
778 				 struct dma_slave_config *config)
779 {
780 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
781 	struct dma_slave_config *slave_cfg = &schan->slave_cfg;
782 
783 	if (!is_slave_direction(config->direction))
784 		return -EINVAL;
785 
786 	memcpy(slave_cfg, config, sizeof(*config));
787 	return 0;
788 }
789 
790 static int sprd_dma_pause(struct dma_chan *chan)
791 {
792 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
793 	unsigned long flags;
794 
795 	spin_lock_irqsave(&schan->vc.lock, flags);
796 	sprd_dma_pause_resume(schan, true);
797 	spin_unlock_irqrestore(&schan->vc.lock, flags);
798 
799 	return 0;
800 }
801 
802 static int sprd_dma_resume(struct dma_chan *chan)
803 {
804 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
805 	unsigned long flags;
806 
807 	spin_lock_irqsave(&schan->vc.lock, flags);
808 	sprd_dma_pause_resume(schan, false);
809 	spin_unlock_irqrestore(&schan->vc.lock, flags);
810 
811 	return 0;
812 }
813 
814 static int sprd_dma_terminate_all(struct dma_chan *chan)
815 {
816 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
817 	unsigned long flags;
818 	LIST_HEAD(head);
819 
820 	spin_lock_irqsave(&schan->vc.lock, flags);
821 	sprd_dma_stop(schan);
822 
823 	vchan_get_all_descriptors(&schan->vc, &head);
824 	spin_unlock_irqrestore(&schan->vc.lock, flags);
825 
826 	vchan_dma_desc_free_list(&schan->vc, &head);
827 	return 0;
828 }
829 
830 static void sprd_dma_free_desc(struct virt_dma_desc *vd)
831 {
832 	struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
833 
834 	kfree(sdesc);
835 }
836 
837 static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param)
838 {
839 	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
840 	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
841 	u32 req = *(u32 *)param;
842 
843 	if (req < sdev->total_chns)
844 		return req == schan->chn_num + 1;
845 	else
846 		return false;
847 }
848 
849 static int sprd_dma_probe(struct platform_device *pdev)
850 {
851 	struct device_node *np = pdev->dev.of_node;
852 	struct sprd_dma_dev *sdev;
853 	struct sprd_dma_chn *dma_chn;
854 	struct resource *res;
855 	u32 chn_count;
856 	int ret, i;
857 
858 	ret = device_property_read_u32(&pdev->dev, "#dma-channels", &chn_count);
859 	if (ret) {
860 		dev_err(&pdev->dev, "get dma channels count failed\n");
861 		return ret;
862 	}
863 
864 	sdev = devm_kzalloc(&pdev->dev,
865 			    struct_size(sdev, channels, chn_count),
866 			    GFP_KERNEL);
867 	if (!sdev)
868 		return -ENOMEM;
869 
870 	sdev->clk = devm_clk_get(&pdev->dev, "enable");
871 	if (IS_ERR(sdev->clk)) {
872 		dev_err(&pdev->dev, "get enable clock failed\n");
873 		return PTR_ERR(sdev->clk);
874 	}
875 
876 	/* ashb clock is optional for AGCP DMA */
877 	sdev->ashb_clk = devm_clk_get(&pdev->dev, "ashb_eb");
878 	if (IS_ERR(sdev->ashb_clk))
879 		dev_warn(&pdev->dev, "no optional ashb eb clock\n");
880 
881 	/*
882 	 * We have three DMA controllers: AP DMA, AON DMA and AGCP DMA. For AGCP
883 	 * DMA controller, it can or do not request the irq, which will save
884 	 * system power without resuming system by DMA interrupts if AGCP DMA
885 	 * does not request the irq. Thus the DMA interrupts property should
886 	 * be optional.
887 	 */
888 	sdev->irq = platform_get_irq(pdev, 0);
889 	if (sdev->irq > 0) {
890 		ret = devm_request_irq(&pdev->dev, sdev->irq, dma_irq_handle,
891 				       0, "sprd_dma", (void *)sdev);
892 		if (ret < 0) {
893 			dev_err(&pdev->dev, "request dma irq failed\n");
894 			return ret;
895 		}
896 	} else {
897 		dev_warn(&pdev->dev, "no interrupts for the dma controller\n");
898 	}
899 
900 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
901 	sdev->glb_base = devm_ioremap_resource(&pdev->dev, res);
902 	if (IS_ERR(sdev->glb_base))
903 		return PTR_ERR(sdev->glb_base);
904 
905 	dma_cap_set(DMA_MEMCPY, sdev->dma_dev.cap_mask);
906 	sdev->total_chns = chn_count;
907 	sdev->dma_dev.chancnt = chn_count;
908 	INIT_LIST_HEAD(&sdev->dma_dev.channels);
909 	INIT_LIST_HEAD(&sdev->dma_dev.global_node);
910 	sdev->dma_dev.dev = &pdev->dev;
911 	sdev->dma_dev.device_alloc_chan_resources = sprd_dma_alloc_chan_resources;
912 	sdev->dma_dev.device_free_chan_resources = sprd_dma_free_chan_resources;
913 	sdev->dma_dev.device_tx_status = sprd_dma_tx_status;
914 	sdev->dma_dev.device_issue_pending = sprd_dma_issue_pending;
915 	sdev->dma_dev.device_prep_dma_memcpy = sprd_dma_prep_dma_memcpy;
916 	sdev->dma_dev.device_prep_slave_sg = sprd_dma_prep_slave_sg;
917 	sdev->dma_dev.device_config = sprd_dma_slave_config;
918 	sdev->dma_dev.device_pause = sprd_dma_pause;
919 	sdev->dma_dev.device_resume = sprd_dma_resume;
920 	sdev->dma_dev.device_terminate_all = sprd_dma_terminate_all;
921 
922 	for (i = 0; i < chn_count; i++) {
923 		dma_chn = &sdev->channels[i];
924 		dma_chn->chn_num = i;
925 		dma_chn->cur_desc = NULL;
926 		/* get each channel's registers base address. */
927 		dma_chn->chn_base = sdev->glb_base + SPRD_DMA_CHN_REG_OFFSET +
928 				    SPRD_DMA_CHN_REG_LENGTH * i;
929 
930 		dma_chn->vc.desc_free = sprd_dma_free_desc;
931 		vchan_init(&dma_chn->vc, &sdev->dma_dev);
932 	}
933 
934 	platform_set_drvdata(pdev, sdev);
935 	ret = sprd_dma_enable(sdev);
936 	if (ret)
937 		return ret;
938 
939 	pm_runtime_set_active(&pdev->dev);
940 	pm_runtime_enable(&pdev->dev);
941 
942 	ret = pm_runtime_get_sync(&pdev->dev);
943 	if (ret < 0)
944 		goto err_rpm;
945 
946 	ret = dma_async_device_register(&sdev->dma_dev);
947 	if (ret < 0) {
948 		dev_err(&pdev->dev, "register dma device failed:%d\n", ret);
949 		goto err_register;
950 	}
951 
952 	sprd_dma_info.dma_cap = sdev->dma_dev.cap_mask;
953 	ret = of_dma_controller_register(np, of_dma_simple_xlate,
954 					 &sprd_dma_info);
955 	if (ret)
956 		goto err_of_register;
957 
958 	pm_runtime_put(&pdev->dev);
959 	return 0;
960 
961 err_of_register:
962 	dma_async_device_unregister(&sdev->dma_dev);
963 err_register:
964 	pm_runtime_put_noidle(&pdev->dev);
965 	pm_runtime_disable(&pdev->dev);
966 err_rpm:
967 	sprd_dma_disable(sdev);
968 	return ret;
969 }
970 
971 static int sprd_dma_remove(struct platform_device *pdev)
972 {
973 	struct sprd_dma_dev *sdev = platform_get_drvdata(pdev);
974 	struct sprd_dma_chn *c, *cn;
975 	int ret;
976 
977 	ret = pm_runtime_get_sync(&pdev->dev);
978 	if (ret < 0)
979 		return ret;
980 
981 	/* explicitly free the irq */
982 	if (sdev->irq > 0)
983 		devm_free_irq(&pdev->dev, sdev->irq, sdev);
984 
985 	list_for_each_entry_safe(c, cn, &sdev->dma_dev.channels,
986 				 vc.chan.device_node) {
987 		list_del(&c->vc.chan.device_node);
988 		tasklet_kill(&c->vc.task);
989 	}
990 
991 	of_dma_controller_free(pdev->dev.of_node);
992 	dma_async_device_unregister(&sdev->dma_dev);
993 	sprd_dma_disable(sdev);
994 
995 	pm_runtime_put_noidle(&pdev->dev);
996 	pm_runtime_disable(&pdev->dev);
997 	return 0;
998 }
999 
1000 static const struct of_device_id sprd_dma_match[] = {
1001 	{ .compatible = "sprd,sc9860-dma", },
1002 	{},
1003 };
1004 
1005 static int __maybe_unused sprd_dma_runtime_suspend(struct device *dev)
1006 {
1007 	struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
1008 
1009 	sprd_dma_disable(sdev);
1010 	return 0;
1011 }
1012 
1013 static int __maybe_unused sprd_dma_runtime_resume(struct device *dev)
1014 {
1015 	struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
1016 	int ret;
1017 
1018 	ret = sprd_dma_enable(sdev);
1019 	if (ret)
1020 		dev_err(sdev->dma_dev.dev, "enable dma failed\n");
1021 
1022 	return ret;
1023 }
1024 
1025 static const struct dev_pm_ops sprd_dma_pm_ops = {
1026 	SET_RUNTIME_PM_OPS(sprd_dma_runtime_suspend,
1027 			   sprd_dma_runtime_resume,
1028 			   NULL)
1029 };
1030 
1031 static struct platform_driver sprd_dma_driver = {
1032 	.probe = sprd_dma_probe,
1033 	.remove = sprd_dma_remove,
1034 	.driver = {
1035 		.name = "sprd-dma",
1036 		.of_match_table = sprd_dma_match,
1037 		.pm = &sprd_dma_pm_ops,
1038 	},
1039 };
1040 module_platform_driver(sprd_dma_driver);
1041 
1042 MODULE_LICENSE("GPL v2");
1043 MODULE_DESCRIPTION("DMA driver for Spreadtrum");
1044 MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
1045 MODULE_ALIAS("platform:sprd-dma");
1046