1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * IMG Multi-threaded DMA Controller (MDC)
4 *
5 * Copyright (C) 2009,2012,2013 Imagination Technologies Ltd.
6 * Copyright (C) 2014 Google, Inc.
7 */
8
9#include <linux/clk.h>
10#include <linux/dma-mapping.h>
11#include <linux/dmaengine.h>
12#include <linux/dmapool.h>
13#include <linux/interrupt.h>
14#include <linux/io.h>
15#include <linux/irq.h>
16#include <linux/kernel.h>
17#include <linux/mfd/syscon.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/of_dma.h>
21#include <linux/platform_device.h>
22#include <linux/pm_runtime.h>
23#include <linux/regmap.h>
24#include <linux/slab.h>
25#include <linux/spinlock.h>
26
27#include "dmaengine.h"
28#include "virt-dma.h"
29
30#define MDC_MAX_DMA_CHANNELS			32
31
32#define MDC_GENERAL_CONFIG			0x000
33#define MDC_GENERAL_CONFIG_LIST_IEN		BIT(31)
34#define MDC_GENERAL_CONFIG_IEN			BIT(29)
35#define MDC_GENERAL_CONFIG_LEVEL_INT		BIT(28)
36#define MDC_GENERAL_CONFIG_INC_W		BIT(12)
37#define MDC_GENERAL_CONFIG_INC_R		BIT(8)
38#define MDC_GENERAL_CONFIG_PHYSICAL_W		BIT(7)
39#define MDC_GENERAL_CONFIG_WIDTH_W_SHIFT	4
40#define MDC_GENERAL_CONFIG_WIDTH_W_MASK		0x7
41#define MDC_GENERAL_CONFIG_PHYSICAL_R		BIT(3)
42#define MDC_GENERAL_CONFIG_WIDTH_R_SHIFT	0
43#define MDC_GENERAL_CONFIG_WIDTH_R_MASK		0x7
44
45#define MDC_READ_PORT_CONFIG			0x004
46#define MDC_READ_PORT_CONFIG_STHREAD_SHIFT	28
47#define MDC_READ_PORT_CONFIG_STHREAD_MASK	0xf
48#define MDC_READ_PORT_CONFIG_RTHREAD_SHIFT	24
49#define MDC_READ_PORT_CONFIG_RTHREAD_MASK	0xf
50#define MDC_READ_PORT_CONFIG_WTHREAD_SHIFT	16
51#define MDC_READ_PORT_CONFIG_WTHREAD_MASK	0xf
52#define MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT	4
53#define MDC_READ_PORT_CONFIG_BURST_SIZE_MASK	0xff
54#define MDC_READ_PORT_CONFIG_DREQ_ENABLE	BIT(1)
55
56#define MDC_READ_ADDRESS			0x008
57
58#define MDC_WRITE_ADDRESS			0x00c
59
60#define MDC_TRANSFER_SIZE			0x010
61#define MDC_TRANSFER_SIZE_MASK			0xffffff
62
63#define MDC_LIST_NODE_ADDRESS			0x014
64
65#define MDC_CMDS_PROCESSED			0x018
66#define MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT	16
67#define MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK	0x3f
68#define MDC_CMDS_PROCESSED_INT_ACTIVE		BIT(8)
69#define MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT	0
70#define MDC_CMDS_PROCESSED_CMDS_DONE_MASK	0x3f
71
72#define MDC_CONTROL_AND_STATUS			0x01c
73#define MDC_CONTROL_AND_STATUS_CANCEL		BIT(20)
74#define MDC_CONTROL_AND_STATUS_LIST_EN		BIT(4)
75#define MDC_CONTROL_AND_STATUS_EN		BIT(0)
76
77#define MDC_ACTIVE_TRANSFER_SIZE		0x030
78
79#define MDC_GLOBAL_CONFIG_A				0x900
80#define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT	16
81#define MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK	0xff
82#define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT		8
83#define MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK		0xff
84#define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT		0
85#define MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK		0xff
86
87struct mdc_hw_list_desc {
88	u32 gen_conf;
89	u32 readport_conf;
90	u32 read_addr;
91	u32 write_addr;
92	u32 xfer_size;
93	u32 node_addr;
94	u32 cmds_done;
95	u32 ctrl_status;
96	/*
97	 * Not part of the list descriptor, but instead used by the CPU to
98	 * traverse the list.
99	 */
100	struct mdc_hw_list_desc *next_desc;
101};
102
103struct mdc_tx_desc {
104	struct mdc_chan *chan;
105	struct virt_dma_desc vd;
106	dma_addr_t list_phys;
107	struct mdc_hw_list_desc *list;
108	bool cyclic;
109	bool cmd_loaded;
110	unsigned int list_len;
111	unsigned int list_period_len;
112	size_t list_xfer_size;
113	unsigned int list_cmds_done;
114};
115
116struct mdc_chan {
117	struct mdc_dma *mdma;
118	struct virt_dma_chan vc;
119	struct dma_slave_config config;
120	struct mdc_tx_desc *desc;
121	int irq;
122	unsigned int periph;
123	unsigned int thread;
124	unsigned int chan_nr;
125};
126
127struct mdc_dma_soc_data {
128	void (*enable_chan)(struct mdc_chan *mchan);
129	void (*disable_chan)(struct mdc_chan *mchan);
130};
131
132struct mdc_dma {
133	struct dma_device dma_dev;
134	void __iomem *regs;
135	struct clk *clk;
136	struct dma_pool *desc_pool;
137	struct regmap *periph_regs;
138	spinlock_t lock;
139	unsigned int nr_threads;
140	unsigned int nr_channels;
141	unsigned int bus_width;
142	unsigned int max_burst_mult;
143	unsigned int max_xfer_size;
144	const struct mdc_dma_soc_data *soc;
145	struct mdc_chan channels[MDC_MAX_DMA_CHANNELS];
146};
147
148static inline u32 mdc_readl(struct mdc_dma *mdma, u32 reg)
149{
150	return readl(mdma->regs + reg);
151}
152
153static inline void mdc_writel(struct mdc_dma *mdma, u32 val, u32 reg)
154{
155	writel(val, mdma->regs + reg);
156}
157
158static inline u32 mdc_chan_readl(struct mdc_chan *mchan, u32 reg)
159{
160	return mdc_readl(mchan->mdma, mchan->chan_nr * 0x040 + reg);
161}
162
163static inline void mdc_chan_writel(struct mdc_chan *mchan, u32 val, u32 reg)
164{
165	mdc_writel(mchan->mdma, val, mchan->chan_nr * 0x040 + reg);
166}
167
168static inline struct mdc_chan *to_mdc_chan(struct dma_chan *c)
169{
170	return container_of(to_virt_chan(c), struct mdc_chan, vc);
171}
172
173static inline struct mdc_tx_desc *to_mdc_desc(struct dma_async_tx_descriptor *t)
174{
175	struct virt_dma_desc *vdesc = container_of(t, struct virt_dma_desc, tx);
176
177	return container_of(vdesc, struct mdc_tx_desc, vd);
178}
179
180static inline struct device *mdma2dev(struct mdc_dma *mdma)
181{
182	return mdma->dma_dev.dev;
183}
184
185static inline unsigned int to_mdc_width(unsigned int bytes)
186{
187	return ffs(bytes) - 1;
188}
189
190static inline void mdc_set_read_width(struct mdc_hw_list_desc *ldesc,
191				      unsigned int bytes)
192{
193	ldesc->gen_conf |= to_mdc_width(bytes) <<
194		MDC_GENERAL_CONFIG_WIDTH_R_SHIFT;
195}
196
197static inline void mdc_set_write_width(struct mdc_hw_list_desc *ldesc,
198				       unsigned int bytes)
199{
200	ldesc->gen_conf |= to_mdc_width(bytes) <<
201		MDC_GENERAL_CONFIG_WIDTH_W_SHIFT;
202}
203
204static void mdc_list_desc_config(struct mdc_chan *mchan,
205				 struct mdc_hw_list_desc *ldesc,
206				 enum dma_transfer_direction dir,
207				 dma_addr_t src, dma_addr_t dst, size_t len)
208{
209	struct mdc_dma *mdma = mchan->mdma;
210	unsigned int max_burst, burst_size;
211
212	ldesc->gen_conf = MDC_GENERAL_CONFIG_IEN | MDC_GENERAL_CONFIG_LIST_IEN |
213		MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
214		MDC_GENERAL_CONFIG_PHYSICAL_R;
215	ldesc->readport_conf =
216		(mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
217		(mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
218		(mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
219	ldesc->read_addr = src;
220	ldesc->write_addr = dst;
221	ldesc->xfer_size = len - 1;
222	ldesc->node_addr = 0;
223	ldesc->cmds_done = 0;
224	ldesc->ctrl_status = MDC_CONTROL_AND_STATUS_LIST_EN |
225		MDC_CONTROL_AND_STATUS_EN;
226	ldesc->next_desc = NULL;
227
228	if (IS_ALIGNED(dst, mdma->bus_width) &&
229	    IS_ALIGNED(src, mdma->bus_width))
230		max_burst = mdma->bus_width * mdma->max_burst_mult;
231	else
232		max_burst = mdma->bus_width * (mdma->max_burst_mult - 1);
233
234	if (dir == DMA_MEM_TO_DEV) {
235		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R;
236		ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
237		mdc_set_read_width(ldesc, mdma->bus_width);
238		mdc_set_write_width(ldesc, mchan->config.dst_addr_width);
239		burst_size = min(max_burst, mchan->config.dst_maxburst *
240				 mchan->config.dst_addr_width);
241	} else if (dir == DMA_DEV_TO_MEM) {
242		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_W;
243		ldesc->readport_conf |= MDC_READ_PORT_CONFIG_DREQ_ENABLE;
244		mdc_set_read_width(ldesc, mchan->config.src_addr_width);
245		mdc_set_write_width(ldesc, mdma->bus_width);
246		burst_size = min(max_burst, mchan->config.src_maxburst *
247				 mchan->config.src_addr_width);
248	} else {
249		ldesc->gen_conf |= MDC_GENERAL_CONFIG_INC_R |
250			MDC_GENERAL_CONFIG_INC_W;
251		mdc_set_read_width(ldesc, mdma->bus_width);
252		mdc_set_write_width(ldesc, mdma->bus_width);
253		burst_size = max_burst;
254	}
255	ldesc->readport_conf |= (burst_size - 1) <<
256		MDC_READ_PORT_CONFIG_BURST_SIZE_SHIFT;
257}
258
259static void mdc_list_desc_free(struct mdc_tx_desc *mdesc)
260{
261	struct mdc_dma *mdma = mdesc->chan->mdma;
262	struct mdc_hw_list_desc *curr, *next;
263	dma_addr_t curr_phys, next_phys;
264
265	curr = mdesc->list;
266	curr_phys = mdesc->list_phys;
267	while (curr) {
268		next = curr->next_desc;
269		next_phys = curr->node_addr;
270		dma_pool_free(mdma->desc_pool, curr, curr_phys);
271		curr = next;
272		curr_phys = next_phys;
273	}
274}
275
276static void mdc_desc_free(struct virt_dma_desc *vd)
277{
278	struct mdc_tx_desc *mdesc = to_mdc_desc(&vd->tx);
279
280	mdc_list_desc_free(mdesc);
281	kfree(mdesc);
282}
283
284static struct dma_async_tx_descriptor *mdc_prep_dma_memcpy(
285	struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len,
286	unsigned long flags)
287{
288	struct mdc_chan *mchan = to_mdc_chan(chan);
289	struct mdc_dma *mdma = mchan->mdma;
290	struct mdc_tx_desc *mdesc;
291	struct mdc_hw_list_desc *curr, *prev = NULL;
292	dma_addr_t curr_phys;
293
294	if (!len)
295		return NULL;
296
297	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
298	if (!mdesc)
299		return NULL;
300	mdesc->chan = mchan;
301	mdesc->list_xfer_size = len;
302
303	while (len > 0) {
304		size_t xfer_size;
305
306		curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT, &curr_phys);
307		if (!curr)
308			goto free_desc;
309
310		if (prev) {
311			prev->node_addr = curr_phys;
312			prev->next_desc = curr;
313		} else {
314			mdesc->list_phys = curr_phys;
315			mdesc->list = curr;
316		}
317
318		xfer_size = min_t(size_t, mdma->max_xfer_size, len);
319
320		mdc_list_desc_config(mchan, curr, DMA_MEM_TO_MEM, src, dest,
321				     xfer_size);
322
323		prev = curr;
324
325		mdesc->list_len++;
326		src += xfer_size;
327		dest += xfer_size;
328		len -= xfer_size;
329	}
330
331	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
332
333free_desc:
334	mdc_desc_free(&mdesc->vd);
335
336	return NULL;
337}
338
339static int mdc_check_slave_width(struct mdc_chan *mchan,
340				 enum dma_transfer_direction dir)
341{
342	enum dma_slave_buswidth width;
343
344	if (dir == DMA_MEM_TO_DEV)
345		width = mchan->config.dst_addr_width;
346	else
347		width = mchan->config.src_addr_width;
348
349	switch (width) {
350	case DMA_SLAVE_BUSWIDTH_1_BYTE:
351	case DMA_SLAVE_BUSWIDTH_2_BYTES:
352	case DMA_SLAVE_BUSWIDTH_4_BYTES:
353	case DMA_SLAVE_BUSWIDTH_8_BYTES:
354		break;
355	default:
356		return -EINVAL;
357	}
358
359	if (width > mchan->mdma->bus_width)
360		return -EINVAL;
361
362	return 0;
363}
364
365static struct dma_async_tx_descriptor *mdc_prep_dma_cyclic(
366	struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
367	size_t period_len, enum dma_transfer_direction dir,
368	unsigned long flags)
369{
370	struct mdc_chan *mchan = to_mdc_chan(chan);
371	struct mdc_dma *mdma = mchan->mdma;
372	struct mdc_tx_desc *mdesc;
373	struct mdc_hw_list_desc *curr, *prev = NULL;
374	dma_addr_t curr_phys;
375
376	if (!buf_len && !period_len)
377		return NULL;
378
379	if (!is_slave_direction(dir))
380		return NULL;
381
382	if (mdc_check_slave_width(mchan, dir) < 0)
383		return NULL;
384
385	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
386	if (!mdesc)
387		return NULL;
388	mdesc->chan = mchan;
389	mdesc->cyclic = true;
390	mdesc->list_xfer_size = buf_len;
391	mdesc->list_period_len = DIV_ROUND_UP(period_len,
392					      mdma->max_xfer_size);
393
394	while (buf_len > 0) {
395		size_t remainder = min(period_len, buf_len);
396
397		while (remainder > 0) {
398			size_t xfer_size;
399
400			curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
401					      &curr_phys);
402			if (!curr)
403				goto free_desc;
404
405			if (!prev) {
406				mdesc->list_phys = curr_phys;
407				mdesc->list = curr;
408			} else {
409				prev->node_addr = curr_phys;
410				prev->next_desc = curr;
411			}
412
413			xfer_size = min_t(size_t, mdma->max_xfer_size,
414					  remainder);
415
416			if (dir == DMA_MEM_TO_DEV) {
417				mdc_list_desc_config(mchan, curr, dir,
418						     buf_addr,
419						     mchan->config.dst_addr,
420						     xfer_size);
421			} else {
422				mdc_list_desc_config(mchan, curr, dir,
423						     mchan->config.src_addr,
424						     buf_addr,
425						     xfer_size);
426			}
427
428			prev = curr;
429
430			mdesc->list_len++;
431			buf_addr += xfer_size;
432			buf_len -= xfer_size;
433			remainder -= xfer_size;
434		}
435	}
436	prev->node_addr = mdesc->list_phys;
437
438	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
439
440free_desc:
441	mdc_desc_free(&mdesc->vd);
442
443	return NULL;
444}
445
446static struct dma_async_tx_descriptor *mdc_prep_slave_sg(
447	struct dma_chan *chan, struct scatterlist *sgl,
448	unsigned int sg_len, enum dma_transfer_direction dir,
449	unsigned long flags, void *context)
450{
451	struct mdc_chan *mchan = to_mdc_chan(chan);
452	struct mdc_dma *mdma = mchan->mdma;
453	struct mdc_tx_desc *mdesc;
454	struct scatterlist *sg;
455	struct mdc_hw_list_desc *curr, *prev = NULL;
456	dma_addr_t curr_phys;
457	unsigned int i;
458
459	if (!sgl)
460		return NULL;
461
462	if (!is_slave_direction(dir))
463		return NULL;
464
465	if (mdc_check_slave_width(mchan, dir) < 0)
466		return NULL;
467
468	mdesc = kzalloc(sizeof(*mdesc), GFP_NOWAIT);
469	if (!mdesc)
470		return NULL;
471	mdesc->chan = mchan;
472
473	for_each_sg(sgl, sg, sg_len, i) {
474		dma_addr_t buf = sg_dma_address(sg);
475		size_t buf_len = sg_dma_len(sg);
476
477		while (buf_len > 0) {
478			size_t xfer_size;
479
480			curr = dma_pool_alloc(mdma->desc_pool, GFP_NOWAIT,
481					      &curr_phys);
482			if (!curr)
483				goto free_desc;
484
485			if (!prev) {
486				mdesc->list_phys = curr_phys;
487				mdesc->list = curr;
488			} else {
489				prev->node_addr = curr_phys;
490				prev->next_desc = curr;
491			}
492
493			xfer_size = min_t(size_t, mdma->max_xfer_size,
494					  buf_len);
495
496			if (dir == DMA_MEM_TO_DEV) {
497				mdc_list_desc_config(mchan, curr, dir, buf,
498						     mchan->config.dst_addr,
499						     xfer_size);
500			} else {
501				mdc_list_desc_config(mchan, curr, dir,
502						     mchan->config.src_addr,
503						     buf, xfer_size);
504			}
505
506			prev = curr;
507
508			mdesc->list_len++;
509			mdesc->list_xfer_size += xfer_size;
510			buf += xfer_size;
511			buf_len -= xfer_size;
512		}
513	}
514
515	return vchan_tx_prep(&mchan->vc, &mdesc->vd, flags);
516
517free_desc:
518	mdc_desc_free(&mdesc->vd);
519
520	return NULL;
521}
522
523static void mdc_issue_desc(struct mdc_chan *mchan)
524{
525	struct mdc_dma *mdma = mchan->mdma;
526	struct virt_dma_desc *vd;
527	struct mdc_tx_desc *mdesc;
528	u32 val;
529
530	vd = vchan_next_desc(&mchan->vc);
531	if (!vd)
532		return;
533
534	list_del(&vd->node);
535
536	mdesc = to_mdc_desc(&vd->tx);
537	mchan->desc = mdesc;
538
539	dev_dbg(mdma2dev(mdma), "Issuing descriptor on channel %d\n",
540		mchan->chan_nr);
541
542	mdma->soc->enable_chan(mchan);
543
544	val = mdc_chan_readl(mchan, MDC_GENERAL_CONFIG);
545	val |= MDC_GENERAL_CONFIG_LIST_IEN | MDC_GENERAL_CONFIG_IEN |
546		MDC_GENERAL_CONFIG_LEVEL_INT | MDC_GENERAL_CONFIG_PHYSICAL_W |
547		MDC_GENERAL_CONFIG_PHYSICAL_R;
548	mdc_chan_writel(mchan, val, MDC_GENERAL_CONFIG);
549	val = (mchan->thread << MDC_READ_PORT_CONFIG_STHREAD_SHIFT) |
550		(mchan->thread << MDC_READ_PORT_CONFIG_RTHREAD_SHIFT) |
551		(mchan->thread << MDC_READ_PORT_CONFIG_WTHREAD_SHIFT);
552	mdc_chan_writel(mchan, val, MDC_READ_PORT_CONFIG);
553	mdc_chan_writel(mchan, mdesc->list_phys, MDC_LIST_NODE_ADDRESS);
554	val = mdc_chan_readl(mchan, MDC_CONTROL_AND_STATUS);
555	val |= MDC_CONTROL_AND_STATUS_LIST_EN;
556	mdc_chan_writel(mchan, val, MDC_CONTROL_AND_STATUS);
557}
558
559static void mdc_issue_pending(struct dma_chan *chan)
560{
561	struct mdc_chan *mchan = to_mdc_chan(chan);
562	unsigned long flags;
563
564	spin_lock_irqsave(&mchan->vc.lock, flags);
565	if (vchan_issue_pending(&mchan->vc) && !mchan->desc)
566		mdc_issue_desc(mchan);
567	spin_unlock_irqrestore(&mchan->vc.lock, flags);
568}
569
570static enum dma_status mdc_tx_status(struct dma_chan *chan,
571	dma_cookie_t cookie, struct dma_tx_state *txstate)
572{
573	struct mdc_chan *mchan = to_mdc_chan(chan);
574	struct mdc_tx_desc *mdesc;
575	struct virt_dma_desc *vd;
576	unsigned long flags;
577	size_t bytes = 0;
578	int ret;
579
580	ret = dma_cookie_status(chan, cookie, txstate);
581	if (ret == DMA_COMPLETE)
582		return ret;
583
584	if (!txstate)
585		return ret;
586
587	spin_lock_irqsave(&mchan->vc.lock, flags);
588	vd = vchan_find_desc(&mchan->vc, cookie);
589	if (vd) {
590		mdesc = to_mdc_desc(&vd->tx);
591		bytes = mdesc->list_xfer_size;
592	} else if (mchan->desc && mchan->desc->vd.tx.cookie == cookie) {
593		struct mdc_hw_list_desc *ldesc;
594		u32 val1, val2, done, processed, residue;
595		int i, cmds;
596
597		mdesc = mchan->desc;
598
599		/*
600		 * Determine the number of commands that haven't been
601		 * processed (handled by the IRQ handler) yet.
602		 */
603		do {
604			val1 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
605				~MDC_CMDS_PROCESSED_INT_ACTIVE;
606			residue = mdc_chan_readl(mchan,
607						 MDC_ACTIVE_TRANSFER_SIZE);
608			val2 = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED) &
609				~MDC_CMDS_PROCESSED_INT_ACTIVE;
610		} while (val1 != val2);
611
612		done = (val1 >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
613			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
614		processed = (val1 >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
615			MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
616		cmds = (done - processed) %
617			(MDC_CMDS_PROCESSED_CMDS_DONE_MASK + 1);
618
619		/*
620		 * If the command loaded event hasn't been processed yet, then
621		 * the difference above includes an extra command.
622		 */
623		if (!mdesc->cmd_loaded)
624			cmds--;
625		else
626			cmds += mdesc->list_cmds_done;
627
628		bytes = mdesc->list_xfer_size;
629		ldesc = mdesc->list;
630		for (i = 0; i < cmds; i++) {
631			bytes -= ldesc->xfer_size + 1;
632			ldesc = ldesc->next_desc;
633		}
634		if (ldesc) {
635			if (residue != MDC_TRANSFER_SIZE_MASK)
636				bytes -= ldesc->xfer_size - residue;
637			else
638				bytes -= ldesc->xfer_size + 1;
639		}
640	}
641	spin_unlock_irqrestore(&mchan->vc.lock, flags);
642
643	dma_set_residue(txstate, bytes);
644
645	return ret;
646}
647
648static unsigned int mdc_get_new_events(struct mdc_chan *mchan)
649{
650	u32 val, processed, done1, done2;
651	unsigned int ret;
652
653	val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
654	processed = (val >> MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) &
655				MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK;
656	/*
657	 * CMDS_DONE may have incremented between reading CMDS_PROCESSED
658	 * and clearing INT_ACTIVE.  Re-read CMDS_PROCESSED to ensure we
659	 * didn't miss a command completion.
660	 */
661	do {
662		val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
663
664		done1 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
665			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
666
667		val &= ~((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK <<
668			  MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT) |
669			 MDC_CMDS_PROCESSED_INT_ACTIVE);
670
671		val |= done1 << MDC_CMDS_PROCESSED_CMDS_PROCESSED_SHIFT;
672
673		mdc_chan_writel(mchan, val, MDC_CMDS_PROCESSED);
674
675		val = mdc_chan_readl(mchan, MDC_CMDS_PROCESSED);
676
677		done2 = (val >> MDC_CMDS_PROCESSED_CMDS_DONE_SHIFT) &
678			MDC_CMDS_PROCESSED_CMDS_DONE_MASK;
679	} while (done1 != done2);
680
681	if (done1 >= processed)
682		ret = done1 - processed;
683	else
684		ret = ((MDC_CMDS_PROCESSED_CMDS_PROCESSED_MASK + 1) -
685			processed) + done1;
686
687	return ret;
688}
689
690static int mdc_terminate_all(struct dma_chan *chan)
691{
692	struct mdc_chan *mchan = to_mdc_chan(chan);
693	unsigned long flags;
694	LIST_HEAD(head);
695
696	spin_lock_irqsave(&mchan->vc.lock, flags);
697
698	mdc_chan_writel(mchan, MDC_CONTROL_AND_STATUS_CANCEL,
699			MDC_CONTROL_AND_STATUS);
700
701	if (mchan->desc) {
702		vchan_terminate_vdesc(&mchan->desc->vd);
703		mchan->desc = NULL;
704	}
705	vchan_get_all_descriptors(&mchan->vc, &head);
706
707	mdc_get_new_events(mchan);
708
709	spin_unlock_irqrestore(&mchan->vc.lock, flags);
710
711	vchan_dma_desc_free_list(&mchan->vc, &head);
712
713	return 0;
714}
715
716static void mdc_synchronize(struct dma_chan *chan)
717{
718	struct mdc_chan *mchan = to_mdc_chan(chan);
719
720	vchan_synchronize(&mchan->vc);
721}
722
723static int mdc_slave_config(struct dma_chan *chan,
724			    struct dma_slave_config *config)
725{
726	struct mdc_chan *mchan = to_mdc_chan(chan);
727	unsigned long flags;
728
729	spin_lock_irqsave(&mchan->vc.lock, flags);
730	mchan->config = *config;
731	spin_unlock_irqrestore(&mchan->vc.lock, flags);
732
733	return 0;
734}
735
736static int mdc_alloc_chan_resources(struct dma_chan *chan)
737{
738	struct mdc_chan *mchan = to_mdc_chan(chan);
739	struct device *dev = mdma2dev(mchan->mdma);
740
741	return pm_runtime_get_sync(dev);
742}
743
744static void mdc_free_chan_resources(struct dma_chan *chan)
745{
746	struct mdc_chan *mchan = to_mdc_chan(chan);
747	struct mdc_dma *mdma = mchan->mdma;
748	struct device *dev = mdma2dev(mdma);
749
750	mdc_terminate_all(chan);
751	mdma->soc->disable_chan(mchan);
752	pm_runtime_put(dev);
753}
754
755static irqreturn_t mdc_chan_irq(int irq, void *dev_id)
756{
757	struct mdc_chan *mchan = (struct mdc_chan *)dev_id;
758	struct mdc_tx_desc *mdesc;
759	unsigned int i, new_events;
760
761	spin_lock(&mchan->vc.lock);
762
763	dev_dbg(mdma2dev(mchan->mdma), "IRQ on channel %d\n", mchan->chan_nr);
764
765	new_events = mdc_get_new_events(mchan);
766
767	if (!new_events)
768		goto out;
769
770	mdesc = mchan->desc;
771	if (!mdesc) {
772		dev_warn(mdma2dev(mchan->mdma),
773			 "IRQ with no active descriptor on channel %d\n",
774			 mchan->chan_nr);
775		goto out;
776	}
777
778	for (i = 0; i < new_events; i++) {
779		/*
780		 * The first interrupt in a transfer indicates that the
781		 * command list has been loaded, not that a command has
782		 * been completed.
783		 */
784		if (!mdesc->cmd_loaded) {
785			mdesc->cmd_loaded = true;
786			continue;
787		}
788
789		mdesc->list_cmds_done++;
790		if (mdesc->cyclic) {
791			mdesc->list_cmds_done %= mdesc->list_len;
792			if (mdesc->list_cmds_done % mdesc->list_period_len == 0)
793				vchan_cyclic_callback(&mdesc->vd);
794		} else if (mdesc->list_cmds_done == mdesc->list_len) {
795			mchan->desc = NULL;
796			vchan_cookie_complete(&mdesc->vd);
797			mdc_issue_desc(mchan);
798			break;
799		}
800	}
801out:
802	spin_unlock(&mchan->vc.lock);
803
804	return IRQ_HANDLED;
805}
806
807static struct dma_chan *mdc_of_xlate(struct of_phandle_args *dma_spec,
808				     struct of_dma *ofdma)
809{
810	struct mdc_dma *mdma = ofdma->of_dma_data;
811	struct dma_chan *chan;
812
813	if (dma_spec->args_count != 3)
814		return NULL;
815
816	list_for_each_entry(chan, &mdma->dma_dev.channels, device_node) {
817		struct mdc_chan *mchan = to_mdc_chan(chan);
818
819		if (!(dma_spec->args[1] & BIT(mchan->chan_nr)))
820			continue;
821		if (dma_get_slave_channel(chan)) {
822			mchan->periph = dma_spec->args[0];
823			mchan->thread = dma_spec->args[2];
824			return chan;
825		}
826	}
827
828	return NULL;
829}
830
831#define PISTACHIO_CR_PERIPH_DMA_ROUTE(ch)	(0x120 + 0x4 * ((ch) / 4))
832#define PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(ch) (8 * ((ch) % 4))
833#define PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK	0x3f
834
835static void pistachio_mdc_enable_chan(struct mdc_chan *mchan)
836{
837	struct mdc_dma *mdma = mchan->mdma;
838
839	regmap_update_bits(mdma->periph_regs,
840			   PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
841			   PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
842			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
843			   mchan->periph <<
844			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr));
845}
846
847static void pistachio_mdc_disable_chan(struct mdc_chan *mchan)
848{
849	struct mdc_dma *mdma = mchan->mdma;
850
851	regmap_update_bits(mdma->periph_regs,
852			   PISTACHIO_CR_PERIPH_DMA_ROUTE(mchan->chan_nr),
853			   PISTACHIO_CR_PERIPH_DMA_ROUTE_MASK <<
854			   PISTACHIO_CR_PERIPH_DMA_ROUTE_SHIFT(mchan->chan_nr),
855			   0);
856}
857
858static const struct mdc_dma_soc_data pistachio_mdc_data = {
859	.enable_chan = pistachio_mdc_enable_chan,
860	.disable_chan = pistachio_mdc_disable_chan,
861};
862
863static const struct of_device_id mdc_dma_of_match[] = {
864	{ .compatible = "img,pistachio-mdc-dma", .data = &pistachio_mdc_data, },
865	{ },
866};
867MODULE_DEVICE_TABLE(of, mdc_dma_of_match);
868
869static int img_mdc_runtime_suspend(struct device *dev)
870{
871	struct mdc_dma *mdma = dev_get_drvdata(dev);
872
873	clk_disable_unprepare(mdma->clk);
874
875	return 0;
876}
877
878static int img_mdc_runtime_resume(struct device *dev)
879{
880	struct mdc_dma *mdma = dev_get_drvdata(dev);
881
882	return clk_prepare_enable(mdma->clk);
883}
884
885static int mdc_dma_probe(struct platform_device *pdev)
886{
887	struct mdc_dma *mdma;
888	unsigned int i;
889	u32 val;
890	int ret;
891
892	mdma = devm_kzalloc(&pdev->dev, sizeof(*mdma), GFP_KERNEL);
893	if (!mdma)
894		return -ENOMEM;
895	platform_set_drvdata(pdev, mdma);
896
897	mdma->soc = of_device_get_match_data(&pdev->dev);
898
899	mdma->regs = devm_platform_ioremap_resource(pdev, 0);
900	if (IS_ERR(mdma->regs))
901		return PTR_ERR(mdma->regs);
902
903	mdma->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
904							    "img,cr-periph");
905	if (IS_ERR(mdma->periph_regs))
906		return PTR_ERR(mdma->periph_regs);
907
908	mdma->clk = devm_clk_get(&pdev->dev, "sys");
909	if (IS_ERR(mdma->clk))
910		return PTR_ERR(mdma->clk);
911
912	dma_cap_zero(mdma->dma_dev.cap_mask);
913	dma_cap_set(DMA_SLAVE, mdma->dma_dev.cap_mask);
914	dma_cap_set(DMA_PRIVATE, mdma->dma_dev.cap_mask);
915	dma_cap_set(DMA_CYCLIC, mdma->dma_dev.cap_mask);
916	dma_cap_set(DMA_MEMCPY, mdma->dma_dev.cap_mask);
917
918	val = mdc_readl(mdma, MDC_GLOBAL_CONFIG_A);
919	mdma->nr_channels = (val >> MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_SHIFT) &
920		MDC_GLOBAL_CONFIG_A_DMA_CONTEXTS_MASK;
921	mdma->nr_threads =
922		1 << ((val >> MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_SHIFT) &
923		      MDC_GLOBAL_CONFIG_A_THREAD_ID_WIDTH_MASK);
924	mdma->bus_width =
925		(1 << ((val >> MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_SHIFT) &
926		       MDC_GLOBAL_CONFIG_A_SYS_DAT_WIDTH_MASK)) / 8;
927	/*
928	 * Although transfer sizes of up to MDC_TRANSFER_SIZE_MASK + 1 bytes
929	 * are supported, this makes it possible for the value reported in
930	 * MDC_ACTIVE_TRANSFER_SIZE to be ambiguous - an active transfer size
931	 * of MDC_TRANSFER_SIZE_MASK may indicate either that 0 bytes or
932	 * MDC_TRANSFER_SIZE_MASK + 1 bytes are remaining.  To eliminate this
933	 * ambiguity, restrict transfer sizes to one bus-width less than the
934	 * actual maximum.
935	 */
936	mdma->max_xfer_size = MDC_TRANSFER_SIZE_MASK + 1 - mdma->bus_width;
937
938	of_property_read_u32(pdev->dev.of_node, "dma-channels",
939			     &mdma->nr_channels);
940	ret = of_property_read_u32(pdev->dev.of_node,
941				   "img,max-burst-multiplier",
942				   &mdma->max_burst_mult);
943	if (ret)
944		return ret;
945
946	mdma->dma_dev.dev = &pdev->dev;
947	mdma->dma_dev.device_prep_slave_sg = mdc_prep_slave_sg;
948	mdma->dma_dev.device_prep_dma_cyclic = mdc_prep_dma_cyclic;
949	mdma->dma_dev.device_prep_dma_memcpy = mdc_prep_dma_memcpy;
950	mdma->dma_dev.device_alloc_chan_resources = mdc_alloc_chan_resources;
951	mdma->dma_dev.device_free_chan_resources = mdc_free_chan_resources;
952	mdma->dma_dev.device_tx_status = mdc_tx_status;
953	mdma->dma_dev.device_issue_pending = mdc_issue_pending;
954	mdma->dma_dev.device_terminate_all = mdc_terminate_all;
955	mdma->dma_dev.device_synchronize = mdc_synchronize;
956	mdma->dma_dev.device_config = mdc_slave_config;
957
958	mdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
959	mdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
960	for (i = 1; i <= mdma->bus_width; i <<= 1) {
961		mdma->dma_dev.src_addr_widths |= BIT(i);
962		mdma->dma_dev.dst_addr_widths |= BIT(i);
963	}
964
965	INIT_LIST_HEAD(&mdma->dma_dev.channels);
966	for (i = 0; i < mdma->nr_channels; i++) {
967		struct mdc_chan *mchan = &mdma->channels[i];
968
969		mchan->mdma = mdma;
970		mchan->chan_nr = i;
971		mchan->irq = platform_get_irq(pdev, i);
972		if (mchan->irq < 0)
973			return mchan->irq;
974
975		ret = devm_request_irq(&pdev->dev, mchan->irq, mdc_chan_irq,
976				       IRQ_TYPE_LEVEL_HIGH,
977				       dev_name(&pdev->dev), mchan);
978		if (ret < 0)
979			return ret;
980
981		mchan->vc.desc_free = mdc_desc_free;
982		vchan_init(&mchan->vc, &mdma->dma_dev);
983	}
984
985	mdma->desc_pool = dmam_pool_create(dev_name(&pdev->dev), &pdev->dev,
986					   sizeof(struct mdc_hw_list_desc),
987					   4, 0);
988	if (!mdma->desc_pool)
989		return -ENOMEM;
990
991	pm_runtime_enable(&pdev->dev);
992	if (!pm_runtime_enabled(&pdev->dev)) {
993		ret = img_mdc_runtime_resume(&pdev->dev);
994		if (ret)
995			return ret;
996	}
997
998	ret = dma_async_device_register(&mdma->dma_dev);
999	if (ret)
1000		goto suspend;
1001
1002	ret = of_dma_controller_register(pdev->dev.of_node, mdc_of_xlate, mdma);
1003	if (ret)
1004		goto unregister;
1005
1006	dev_info(&pdev->dev, "MDC with %u channels and %u threads\n",
1007		 mdma->nr_channels, mdma->nr_threads);
1008
1009	return 0;
1010
1011unregister:
1012	dma_async_device_unregister(&mdma->dma_dev);
1013suspend:
1014	if (!pm_runtime_enabled(&pdev->dev))
1015		img_mdc_runtime_suspend(&pdev->dev);
1016	pm_runtime_disable(&pdev->dev);
1017	return ret;
1018}
1019
1020static void mdc_dma_remove(struct platform_device *pdev)
1021{
1022	struct mdc_dma *mdma = platform_get_drvdata(pdev);
1023	struct mdc_chan *mchan, *next;
1024
1025	of_dma_controller_free(pdev->dev.of_node);
1026	dma_async_device_unregister(&mdma->dma_dev);
1027
1028	list_for_each_entry_safe(mchan, next, &mdma->dma_dev.channels,
1029				 vc.chan.device_node) {
1030		list_del(&mchan->vc.chan.device_node);
1031
1032		devm_free_irq(&pdev->dev, mchan->irq, mchan);
1033
1034		tasklet_kill(&mchan->vc.task);
1035	}
1036
1037	pm_runtime_disable(&pdev->dev);
1038	if (!pm_runtime_status_suspended(&pdev->dev))
1039		img_mdc_runtime_suspend(&pdev->dev);
1040}
1041
1042#ifdef CONFIG_PM_SLEEP
1043static int img_mdc_suspend_late(struct device *dev)
1044{
1045	struct mdc_dma *mdma = dev_get_drvdata(dev);
1046	int i;
1047
1048	/* Check that all channels are idle */
1049	for (i = 0; i < mdma->nr_channels; i++) {
1050		struct mdc_chan *mchan = &mdma->channels[i];
1051
1052		if (unlikely(mchan->desc))
1053			return -EBUSY;
1054	}
1055
1056	return pm_runtime_force_suspend(dev);
1057}
1058
1059static int img_mdc_resume_early(struct device *dev)
1060{
1061	return pm_runtime_force_resume(dev);
1062}
1063#endif /* CONFIG_PM_SLEEP */
1064
1065static const struct dev_pm_ops img_mdc_pm_ops = {
1066	SET_RUNTIME_PM_OPS(img_mdc_runtime_suspend,
1067			   img_mdc_runtime_resume, NULL)
1068	SET_LATE_SYSTEM_SLEEP_PM_OPS(img_mdc_suspend_late,
1069				     img_mdc_resume_early)
1070};
1071
1072static struct platform_driver mdc_dma_driver = {
1073	.driver = {
1074		.name = "img-mdc-dma",
1075		.pm = &img_mdc_pm_ops,
1076		.of_match_table = of_match_ptr(mdc_dma_of_match),
1077	},
1078	.probe = mdc_dma_probe,
1079	.remove_new = mdc_dma_remove,
1080};
1081module_platform_driver(mdc_dma_driver);
1082
1083MODULE_DESCRIPTION("IMG Multi-threaded DMA Controller (MDC) driver");
1084MODULE_AUTHOR("Andrew Bresticker <abrestic@chromium.org>");
1085MODULE_LICENSE("GPL v2");
1086