1 /*
2  * driver/dma/coh901318.c
3  *
4  * Copyright (C) 2007-2009 ST-Ericsson
5  * License terms: GNU General Public License (GPL) version 2
6  * DMA driver for COH 901 318
7  * Author: Per Friden <per.friden@stericsson.com>
8  */
9 
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h> /* printk() */
13 #include <linux/fs.h> /* everything... */
14 #include <linux/scatterlist.h>
15 #include <linux/slab.h> /* kmalloc() */
16 #include <linux/dmaengine.h>
17 #include <linux/platform_device.h>
18 #include <linux/device.h>
19 #include <linux/irqreturn.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/uaccess.h>
23 #include <linux/debugfs.h>
24 #include <mach/coh901318.h>
25 
26 #include "coh901318_lli.h"
27 
28 #define COHC_2_DEV(cohc) (&cohc->chan.dev->device)
29 
30 #ifdef VERBOSE_DEBUG
31 #define COH_DBG(x) ({ if (1) x; 0; })
32 #else
33 #define COH_DBG(x) ({ if (0) x; 0; })
34 #endif
35 
36 struct coh901318_desc {
37 	struct dma_async_tx_descriptor desc;
38 	struct list_head node;
39 	struct scatterlist *sg;
40 	unsigned int sg_len;
41 	struct coh901318_lli *lli;
42 	enum dma_transfer_direction dir;
43 	unsigned long flags;
44 	u32 head_config;
45 	u32 head_ctrl;
46 };
47 
48 struct coh901318_base {
49 	struct device *dev;
50 	void __iomem *virtbase;
51 	struct coh901318_pool pool;
52 	struct powersave pm;
53 	struct dma_device dma_slave;
54 	struct dma_device dma_memcpy;
55 	struct coh901318_chan *chans;
56 	struct coh901318_platform *platform;
57 };
58 
59 struct coh901318_chan {
60 	spinlock_t lock;
61 	int allocated;
62 	int completed;
63 	int id;
64 	int stopped;
65 
66 	struct work_struct free_work;
67 	struct dma_chan chan;
68 
69 	struct tasklet_struct tasklet;
70 
71 	struct list_head active;
72 	struct list_head queue;
73 	struct list_head free;
74 
75 	unsigned long nbr_active_done;
76 	unsigned long busy;
77 
78 	u32 runtime_addr;
79 	u32 runtime_ctrl;
80 
81 	struct coh901318_base *base;
82 };
83 
coh901318_list_print(struct coh901318_chan * cohc,struct coh901318_lli * lli)84 static void coh901318_list_print(struct coh901318_chan *cohc,
85 				 struct coh901318_lli *lli)
86 {
87 	struct coh901318_lli *l = lli;
88 	int i = 0;
89 
90 	while (l) {
91 		dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src 0x%x"
92 			 ", dst 0x%x, link 0x%x virt_link_addr 0x%p\n",
93 			 i, l, l->control, l->src_addr, l->dst_addr,
94 			 l->link_addr, l->virt_link_addr);
95 		i++;
96 		l = l->virt_link_addr;
97 	}
98 }
99 
100 #ifdef CONFIG_DEBUG_FS
101 
102 #define COH901318_DEBUGFS_ASSIGN(x, y) (x = y)
103 
104 static struct coh901318_base *debugfs_dma_base;
105 static struct dentry *dma_dentry;
106 
coh901318_debugfs_open(struct inode * inode,struct file * file)107 static int coh901318_debugfs_open(struct inode *inode, struct file *file)
108 {
109 
110 	file->private_data = inode->i_private;
111 	return 0;
112 }
113 
coh901318_debugfs_read(struct file * file,char __user * buf,size_t count,loff_t * f_pos)114 static int coh901318_debugfs_read(struct file *file, char __user *buf,
115 				  size_t count, loff_t *f_pos)
116 {
117 	u64 started_channels = debugfs_dma_base->pm.started_channels;
118 	int pool_count = debugfs_dma_base->pool.debugfs_pool_counter;
119 	int i;
120 	int ret = 0;
121 	char *dev_buf;
122 	char *tmp;
123 	int dev_size;
124 
125 	dev_buf = kmalloc(4*1024, GFP_KERNEL);
126 	if (dev_buf == NULL)
127 		goto err_kmalloc;
128 	tmp = dev_buf;
129 
130 	tmp += sprintf(tmp, "DMA -- enabled dma channels\n");
131 
132 	for (i = 0; i < debugfs_dma_base->platform->max_channels; i++)
133 		if (started_channels & (1 << i))
134 			tmp += sprintf(tmp, "channel %d\n", i);
135 
136 	tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count);
137 	dev_size = tmp  - dev_buf;
138 
139 	/* No more to read if offset != 0 */
140 	if (*f_pos > dev_size)
141 		goto out;
142 
143 	if (count > dev_size - *f_pos)
144 		count = dev_size - *f_pos;
145 
146 	if (copy_to_user(buf, dev_buf + *f_pos, count))
147 		ret = -EINVAL;
148 	ret = count;
149 	*f_pos += count;
150 
151  out:
152 	kfree(dev_buf);
153 	return ret;
154 
155  err_kmalloc:
156 	return 0;
157 }
158 
159 static const struct file_operations coh901318_debugfs_status_operations = {
160 	.owner		= THIS_MODULE,
161 	.open		= coh901318_debugfs_open,
162 	.read		= coh901318_debugfs_read,
163 	.llseek		= default_llseek,
164 };
165 
166 
init_coh901318_debugfs(void)167 static int __init init_coh901318_debugfs(void)
168 {
169 
170 	dma_dentry = debugfs_create_dir("dma", NULL);
171 
172 	(void) debugfs_create_file("status",
173 				   S_IFREG | S_IRUGO,
174 				   dma_dentry, NULL,
175 				   &coh901318_debugfs_status_operations);
176 	return 0;
177 }
178 
exit_coh901318_debugfs(void)179 static void __exit exit_coh901318_debugfs(void)
180 {
181 	debugfs_remove_recursive(dma_dentry);
182 }
183 
184 module_init(init_coh901318_debugfs);
185 module_exit(exit_coh901318_debugfs);
186 #else
187 
188 #define COH901318_DEBUGFS_ASSIGN(x, y)
189 
190 #endif /* CONFIG_DEBUG_FS */
191 
to_coh901318_chan(struct dma_chan * chan)192 static inline struct coh901318_chan *to_coh901318_chan(struct dma_chan *chan)
193 {
194 	return container_of(chan, struct coh901318_chan, chan);
195 }
196 
197 static inline dma_addr_t
cohc_dev_addr(struct coh901318_chan * cohc)198 cohc_dev_addr(struct coh901318_chan *cohc)
199 {
200 	/* Runtime supplied address will take precedence */
201 	if (cohc->runtime_addr)
202 		return cohc->runtime_addr;
203 	return cohc->base->platform->chan_conf[cohc->id].dev_addr;
204 }
205 
206 static inline const struct coh901318_params *
cohc_chan_param(struct coh901318_chan * cohc)207 cohc_chan_param(struct coh901318_chan *cohc)
208 {
209 	return &cohc->base->platform->chan_conf[cohc->id].param;
210 }
211 
212 static inline const struct coh_dma_channel *
cohc_chan_conf(struct coh901318_chan * cohc)213 cohc_chan_conf(struct coh901318_chan *cohc)
214 {
215 	return &cohc->base->platform->chan_conf[cohc->id];
216 }
217 
enable_powersave(struct coh901318_chan * cohc)218 static void enable_powersave(struct coh901318_chan *cohc)
219 {
220 	unsigned long flags;
221 	struct powersave *pm = &cohc->base->pm;
222 
223 	spin_lock_irqsave(&pm->lock, flags);
224 
225 	pm->started_channels &= ~(1ULL << cohc->id);
226 
227 	if (!pm->started_channels) {
228 		/* DMA no longer intends to access memory */
229 		cohc->base->platform->access_memory_state(cohc->base->dev,
230 							  false);
231 	}
232 
233 	spin_unlock_irqrestore(&pm->lock, flags);
234 }
disable_powersave(struct coh901318_chan * cohc)235 static void disable_powersave(struct coh901318_chan *cohc)
236 {
237 	unsigned long flags;
238 	struct powersave *pm = &cohc->base->pm;
239 
240 	spin_lock_irqsave(&pm->lock, flags);
241 
242 	if (!pm->started_channels) {
243 		/* DMA intends to access memory */
244 		cohc->base->platform->access_memory_state(cohc->base->dev,
245 							  true);
246 	}
247 
248 	pm->started_channels |= (1ULL << cohc->id);
249 
250 	spin_unlock_irqrestore(&pm->lock, flags);
251 }
252 
coh901318_set_ctrl(struct coh901318_chan * cohc,u32 control)253 static inline int coh901318_set_ctrl(struct coh901318_chan *cohc, u32 control)
254 {
255 	int channel = cohc->id;
256 	void __iomem *virtbase = cohc->base->virtbase;
257 
258 	writel(control,
259 	       virtbase + COH901318_CX_CTRL +
260 	       COH901318_CX_CTRL_SPACING * channel);
261 	return 0;
262 }
263 
coh901318_set_conf(struct coh901318_chan * cohc,u32 conf)264 static inline int coh901318_set_conf(struct coh901318_chan *cohc, u32 conf)
265 {
266 	int channel = cohc->id;
267 	void __iomem *virtbase = cohc->base->virtbase;
268 
269 	writel(conf,
270 	       virtbase + COH901318_CX_CFG +
271 	       COH901318_CX_CFG_SPACING*channel);
272 	return 0;
273 }
274 
275 
coh901318_start(struct coh901318_chan * cohc)276 static int coh901318_start(struct coh901318_chan *cohc)
277 {
278 	u32 val;
279 	int channel = cohc->id;
280 	void __iomem *virtbase = cohc->base->virtbase;
281 
282 	disable_powersave(cohc);
283 
284 	val = readl(virtbase + COH901318_CX_CFG +
285 		    COH901318_CX_CFG_SPACING * channel);
286 
287 	/* Enable channel */
288 	val |= COH901318_CX_CFG_CH_ENABLE;
289 	writel(val, virtbase + COH901318_CX_CFG +
290 	       COH901318_CX_CFG_SPACING * channel);
291 
292 	return 0;
293 }
294 
coh901318_prep_linked_list(struct coh901318_chan * cohc,struct coh901318_lli * lli)295 static int coh901318_prep_linked_list(struct coh901318_chan *cohc,
296 				      struct coh901318_lli *lli)
297 {
298 	int channel = cohc->id;
299 	void __iomem *virtbase = cohc->base->virtbase;
300 
301 	BUG_ON(readl(virtbase + COH901318_CX_STAT +
302 		     COH901318_CX_STAT_SPACING*channel) &
303 	       COH901318_CX_STAT_ACTIVE);
304 
305 	writel(lli->src_addr,
306 	       virtbase + COH901318_CX_SRC_ADDR +
307 	       COH901318_CX_SRC_ADDR_SPACING * channel);
308 
309 	writel(lli->dst_addr, virtbase +
310 	       COH901318_CX_DST_ADDR +
311 	       COH901318_CX_DST_ADDR_SPACING * channel);
312 
313 	writel(lli->link_addr, virtbase + COH901318_CX_LNK_ADDR +
314 	       COH901318_CX_LNK_ADDR_SPACING * channel);
315 
316 	writel(lli->control, virtbase + COH901318_CX_CTRL +
317 	       COH901318_CX_CTRL_SPACING * channel);
318 
319 	return 0;
320 }
321 static dma_cookie_t
coh901318_assign_cookie(struct coh901318_chan * cohc,struct coh901318_desc * cohd)322 coh901318_assign_cookie(struct coh901318_chan *cohc,
323 			struct coh901318_desc *cohd)
324 {
325 	dma_cookie_t cookie = cohc->chan.cookie;
326 
327 	if (++cookie < 0)
328 		cookie = 1;
329 
330 	cohc->chan.cookie = cookie;
331 	cohd->desc.cookie = cookie;
332 
333 	return cookie;
334 }
335 
336 static struct coh901318_desc *
coh901318_desc_get(struct coh901318_chan * cohc)337 coh901318_desc_get(struct coh901318_chan *cohc)
338 {
339 	struct coh901318_desc *desc;
340 
341 	if (list_empty(&cohc->free)) {
342 		/* alloc new desc because we're out of used ones
343 		 * TODO: alloc a pile of descs instead of just one,
344 		 * avoid many small allocations.
345 		 */
346 		desc = kzalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);
347 		if (desc == NULL)
348 			goto out;
349 		INIT_LIST_HEAD(&desc->node);
350 		dma_async_tx_descriptor_init(&desc->desc, &cohc->chan);
351 	} else {
352 		/* Reuse an old desc. */
353 		desc = list_first_entry(&cohc->free,
354 					struct coh901318_desc,
355 					node);
356 		list_del(&desc->node);
357 		/* Initialize it a bit so it's not insane */
358 		desc->sg = NULL;
359 		desc->sg_len = 0;
360 		desc->desc.callback = NULL;
361 		desc->desc.callback_param = NULL;
362 	}
363 
364  out:
365 	return desc;
366 }
367 
368 static void
coh901318_desc_free(struct coh901318_chan * cohc,struct coh901318_desc * cohd)369 coh901318_desc_free(struct coh901318_chan *cohc, struct coh901318_desc *cohd)
370 {
371 	list_add_tail(&cohd->node, &cohc->free);
372 }
373 
374 /* call with irq lock held */
375 static void
coh901318_desc_submit(struct coh901318_chan * cohc,struct coh901318_desc * desc)376 coh901318_desc_submit(struct coh901318_chan *cohc, struct coh901318_desc *desc)
377 {
378 	list_add_tail(&desc->node, &cohc->active);
379 }
380 
381 static struct coh901318_desc *
coh901318_first_active_get(struct coh901318_chan * cohc)382 coh901318_first_active_get(struct coh901318_chan *cohc)
383 {
384 	struct coh901318_desc *d;
385 
386 	if (list_empty(&cohc->active))
387 		return NULL;
388 
389 	d = list_first_entry(&cohc->active,
390 			     struct coh901318_desc,
391 			     node);
392 	return d;
393 }
394 
395 static void
coh901318_desc_remove(struct coh901318_desc * cohd)396 coh901318_desc_remove(struct coh901318_desc *cohd)
397 {
398 	list_del(&cohd->node);
399 }
400 
401 static void
coh901318_desc_queue(struct coh901318_chan * cohc,struct coh901318_desc * desc)402 coh901318_desc_queue(struct coh901318_chan *cohc, struct coh901318_desc *desc)
403 {
404 	list_add_tail(&desc->node, &cohc->queue);
405 }
406 
407 static struct coh901318_desc *
coh901318_first_queued(struct coh901318_chan * cohc)408 coh901318_first_queued(struct coh901318_chan *cohc)
409 {
410 	struct coh901318_desc *d;
411 
412 	if (list_empty(&cohc->queue))
413 		return NULL;
414 
415 	d = list_first_entry(&cohc->queue,
416 			     struct coh901318_desc,
417 			     node);
418 	return d;
419 }
420 
coh901318_get_bytes_in_lli(struct coh901318_lli * in_lli)421 static inline u32 coh901318_get_bytes_in_lli(struct coh901318_lli *in_lli)
422 {
423 	struct coh901318_lli *lli = in_lli;
424 	u32 bytes = 0;
425 
426 	while (lli) {
427 		bytes += lli->control & COH901318_CX_CTRL_TC_VALUE_MASK;
428 		lli = lli->virt_link_addr;
429 	}
430 	return bytes;
431 }
432 
433 /*
434  * Get the number of bytes left to transfer on this channel,
435  * it is unwise to call this before stopping the channel for
436  * absolute measures, but for a rough guess you can still call
437  * it.
438  */
coh901318_get_bytes_left(struct dma_chan * chan)439 static u32 coh901318_get_bytes_left(struct dma_chan *chan)
440 {
441 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
442 	struct coh901318_desc *cohd;
443 	struct list_head *pos;
444 	unsigned long flags;
445 	u32 left = 0;
446 	int i = 0;
447 
448 	spin_lock_irqsave(&cohc->lock, flags);
449 
450 	/*
451 	 * If there are many queued jobs, we iterate and add the
452 	 * size of them all. We take a special look on the first
453 	 * job though, since it is probably active.
454 	 */
455 	list_for_each(pos, &cohc->active) {
456 		/*
457 		 * The first job in the list will be working on the
458 		 * hardware. The job can be stopped but still active,
459 		 * so that the transfer counter is somewhere inside
460 		 * the buffer.
461 		 */
462 		cohd = list_entry(pos, struct coh901318_desc, node);
463 
464 		if (i == 0) {
465 			struct coh901318_lli *lli;
466 			dma_addr_t ladd;
467 
468 			/* Read current transfer count value */
469 			left = readl(cohc->base->virtbase +
470 				     COH901318_CX_CTRL +
471 				     COH901318_CX_CTRL_SPACING * cohc->id) &
472 				COH901318_CX_CTRL_TC_VALUE_MASK;
473 
474 			/* See if the transfer is linked... */
475 			ladd = readl(cohc->base->virtbase +
476 				     COH901318_CX_LNK_ADDR +
477 				     COH901318_CX_LNK_ADDR_SPACING *
478 				     cohc->id) &
479 				~COH901318_CX_LNK_LINK_IMMEDIATE;
480 			/* Single transaction */
481 			if (!ladd)
482 				continue;
483 
484 			/*
485 			 * Linked transaction, follow the lli, find the
486 			 * currently processing lli, and proceed to the next
487 			 */
488 			lli = cohd->lli;
489 			while (lli && lli->link_addr != ladd)
490 				lli = lli->virt_link_addr;
491 
492 			if (lli)
493 				lli = lli->virt_link_addr;
494 
495 			/*
496 			 * Follow remaining lli links around to count the total
497 			 * number of bytes left
498 			 */
499 			left += coh901318_get_bytes_in_lli(lli);
500 		} else {
501 			left += coh901318_get_bytes_in_lli(cohd->lli);
502 		}
503 		i++;
504 	}
505 
506 	/* Also count bytes in the queued jobs */
507 	list_for_each(pos, &cohc->queue) {
508 		cohd = list_entry(pos, struct coh901318_desc, node);
509 		left += coh901318_get_bytes_in_lli(cohd->lli);
510 	}
511 
512 	spin_unlock_irqrestore(&cohc->lock, flags);
513 
514 	return left;
515 }
516 
517 /*
518  * Pauses a transfer without losing data. Enables power save.
519  * Use this function in conjunction with coh901318_resume.
520  */
coh901318_pause(struct dma_chan * chan)521 static void coh901318_pause(struct dma_chan *chan)
522 {
523 	u32 val;
524 	unsigned long flags;
525 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
526 	int channel = cohc->id;
527 	void __iomem *virtbase = cohc->base->virtbase;
528 
529 	spin_lock_irqsave(&cohc->lock, flags);
530 
531 	/* Disable channel in HW */
532 	val = readl(virtbase + COH901318_CX_CFG +
533 		    COH901318_CX_CFG_SPACING * channel);
534 
535 	/* Stopping infinite transfer */
536 	if ((val & COH901318_CX_CTRL_TC_ENABLE) == 0 &&
537 	    (val & COH901318_CX_CFG_CH_ENABLE))
538 		cohc->stopped = 1;
539 
540 
541 	val &= ~COH901318_CX_CFG_CH_ENABLE;
542 	/* Enable twice, HW bug work around */
543 	writel(val, virtbase + COH901318_CX_CFG +
544 	       COH901318_CX_CFG_SPACING * channel);
545 	writel(val, virtbase + COH901318_CX_CFG +
546 	       COH901318_CX_CFG_SPACING * channel);
547 
548 	/* Spin-wait for it to actually go inactive */
549 	while (readl(virtbase + COH901318_CX_STAT+COH901318_CX_STAT_SPACING *
550 		     channel) & COH901318_CX_STAT_ACTIVE)
551 		cpu_relax();
552 
553 	/* Check if we stopped an active job */
554 	if ((readl(virtbase + COH901318_CX_CTRL+COH901318_CX_CTRL_SPACING *
555 		   channel) & COH901318_CX_CTRL_TC_VALUE_MASK) > 0)
556 		cohc->stopped = 1;
557 
558 	enable_powersave(cohc);
559 
560 	spin_unlock_irqrestore(&cohc->lock, flags);
561 }
562 
563 /* Resumes a transfer that has been stopped via 300_dma_stop(..).
564    Power save is handled.
565 */
coh901318_resume(struct dma_chan * chan)566 static void coh901318_resume(struct dma_chan *chan)
567 {
568 	u32 val;
569 	unsigned long flags;
570 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
571 	int channel = cohc->id;
572 
573 	spin_lock_irqsave(&cohc->lock, flags);
574 
575 	disable_powersave(cohc);
576 
577 	if (cohc->stopped) {
578 		/* Enable channel in HW */
579 		val = readl(cohc->base->virtbase + COH901318_CX_CFG +
580 			    COH901318_CX_CFG_SPACING * channel);
581 
582 		val |= COH901318_CX_CFG_CH_ENABLE;
583 
584 		writel(val, cohc->base->virtbase + COH901318_CX_CFG +
585 		       COH901318_CX_CFG_SPACING*channel);
586 
587 		cohc->stopped = 0;
588 	}
589 
590 	spin_unlock_irqrestore(&cohc->lock, flags);
591 }
592 
coh901318_filter_id(struct dma_chan * chan,void * chan_id)593 bool coh901318_filter_id(struct dma_chan *chan, void *chan_id)
594 {
595 	unsigned int ch_nr = (unsigned int) chan_id;
596 
597 	if (ch_nr == to_coh901318_chan(chan)->id)
598 		return true;
599 
600 	return false;
601 }
602 EXPORT_SYMBOL(coh901318_filter_id);
603 
604 /*
605  * DMA channel allocation
606  */
coh901318_config(struct coh901318_chan * cohc,struct coh901318_params * param)607 static int coh901318_config(struct coh901318_chan *cohc,
608 			    struct coh901318_params *param)
609 {
610 	unsigned long flags;
611 	const struct coh901318_params *p;
612 	int channel = cohc->id;
613 	void __iomem *virtbase = cohc->base->virtbase;
614 
615 	spin_lock_irqsave(&cohc->lock, flags);
616 
617 	if (param)
618 		p = param;
619 	else
620 		p = &cohc->base->platform->chan_conf[channel].param;
621 
622 	/* Clear any pending BE or TC interrupt */
623 	if (channel < 32) {
624 		writel(1 << channel, virtbase + COH901318_BE_INT_CLEAR1);
625 		writel(1 << channel, virtbase + COH901318_TC_INT_CLEAR1);
626 	} else {
627 		writel(1 << (channel - 32), virtbase +
628 		       COH901318_BE_INT_CLEAR2);
629 		writel(1 << (channel - 32), virtbase +
630 		       COH901318_TC_INT_CLEAR2);
631 	}
632 
633 	coh901318_set_conf(cohc, p->config);
634 	coh901318_set_ctrl(cohc, p->ctrl_lli_last);
635 
636 	spin_unlock_irqrestore(&cohc->lock, flags);
637 
638 	return 0;
639 }
640 
641 /* must lock when calling this function
642  * start queued jobs, if any
643  * TODO: start all queued jobs in one go
644  *
645  * Returns descriptor if queued job is started otherwise NULL.
646  * If the queue is empty NULL is returned.
647  */
coh901318_queue_start(struct coh901318_chan * cohc)648 static struct coh901318_desc *coh901318_queue_start(struct coh901318_chan *cohc)
649 {
650 	struct coh901318_desc *cohd;
651 
652 	/*
653 	 * start queued jobs, if any
654 	 * TODO: transmit all queued jobs in one go
655 	 */
656 	cohd = coh901318_first_queued(cohc);
657 
658 	if (cohd != NULL) {
659 		/* Remove from queue */
660 		coh901318_desc_remove(cohd);
661 		/* initiate DMA job */
662 		cohc->busy = 1;
663 
664 		coh901318_desc_submit(cohc, cohd);
665 
666 		/* Program the transaction head */
667 		coh901318_set_conf(cohc, cohd->head_config);
668 		coh901318_set_ctrl(cohc, cohd->head_ctrl);
669 		coh901318_prep_linked_list(cohc, cohd->lli);
670 
671 		/* start dma job on this channel */
672 		coh901318_start(cohc);
673 
674 	}
675 
676 	return cohd;
677 }
678 
679 /*
680  * This tasklet is called from the interrupt handler to
681  * handle each descriptor (DMA job) that is sent to a channel.
682  */
dma_tasklet(unsigned long data)683 static void dma_tasklet(unsigned long data)
684 {
685 	struct coh901318_chan *cohc = (struct coh901318_chan *) data;
686 	struct coh901318_desc *cohd_fin;
687 	unsigned long flags;
688 	dma_async_tx_callback callback;
689 	void *callback_param;
690 
691 	dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d"
692 		 " nbr_active_done %ld\n", __func__,
693 		 cohc->id, cohc->nbr_active_done);
694 
695 	spin_lock_irqsave(&cohc->lock, flags);
696 
697 	/* get first active descriptor entry from list */
698 	cohd_fin = coh901318_first_active_get(cohc);
699 
700 	if (cohd_fin == NULL)
701 		goto err;
702 
703 	/* locate callback to client */
704 	callback = cohd_fin->desc.callback;
705 	callback_param = cohd_fin->desc.callback_param;
706 
707 	/* sign this job as completed on the channel */
708 	cohc->completed = cohd_fin->desc.cookie;
709 
710 	/* release the lli allocation and remove the descriptor */
711 	coh901318_lli_free(&cohc->base->pool, &cohd_fin->lli);
712 
713 	/* return desc to free-list */
714 	coh901318_desc_remove(cohd_fin);
715 	coh901318_desc_free(cohc, cohd_fin);
716 
717 	spin_unlock_irqrestore(&cohc->lock, flags);
718 
719 	/* Call the callback when we're done */
720 	if (callback)
721 		callback(callback_param);
722 
723 	spin_lock_irqsave(&cohc->lock, flags);
724 
725 	/*
726 	 * If another interrupt fired while the tasklet was scheduling,
727 	 * we don't get called twice, so we have this number of active
728 	 * counter that keep track of the number of IRQs expected to
729 	 * be handled for this channel. If there happen to be more than
730 	 * one IRQ to be ack:ed, we simply schedule this tasklet again.
731 	 */
732 	cohc->nbr_active_done--;
733 	if (cohc->nbr_active_done) {
734 		dev_dbg(COHC_2_DEV(cohc), "scheduling tasklet again, new IRQs "
735 			"came in while we were scheduling this tasklet\n");
736 		if (cohc_chan_conf(cohc)->priority_high)
737 			tasklet_hi_schedule(&cohc->tasklet);
738 		else
739 			tasklet_schedule(&cohc->tasklet);
740 	}
741 
742 	spin_unlock_irqrestore(&cohc->lock, flags);
743 
744 	return;
745 
746  err:
747 	spin_unlock_irqrestore(&cohc->lock, flags);
748 	dev_err(COHC_2_DEV(cohc), "[%s] No active dma desc\n", __func__);
749 }
750 
751 
752 /* called from interrupt context */
dma_tc_handle(struct coh901318_chan * cohc)753 static void dma_tc_handle(struct coh901318_chan *cohc)
754 {
755 	/*
756 	 * If the channel is not allocated, then we shouldn't have
757 	 * any TC interrupts on it.
758 	 */
759 	if (!cohc->allocated) {
760 		dev_err(COHC_2_DEV(cohc), "spurious interrupt from "
761 			"unallocated channel\n");
762 		return;
763 	}
764 
765 	spin_lock(&cohc->lock);
766 
767 	/*
768 	 * When we reach this point, at least one queue item
769 	 * should have been moved over from cohc->queue to
770 	 * cohc->active and run to completion, that is why we're
771 	 * getting a terminal count interrupt is it not?
772 	 * If you get this BUG() the most probable cause is that
773 	 * the individual nodes in the lli chain have IRQ enabled,
774 	 * so check your platform config for lli chain ctrl.
775 	 */
776 	BUG_ON(list_empty(&cohc->active));
777 
778 	cohc->nbr_active_done++;
779 
780 	/*
781 	 * This attempt to take a job from cohc->queue, put it
782 	 * into cohc->active and start it.
783 	 */
784 	if (coh901318_queue_start(cohc) == NULL)
785 		cohc->busy = 0;
786 
787 	spin_unlock(&cohc->lock);
788 
789 	/*
790 	 * This tasklet will remove items from cohc->active
791 	 * and thus terminates them.
792 	 */
793 	if (cohc_chan_conf(cohc)->priority_high)
794 		tasklet_hi_schedule(&cohc->tasklet);
795 	else
796 		tasklet_schedule(&cohc->tasklet);
797 }
798 
799 
dma_irq_handler(int irq,void * dev_id)800 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
801 {
802 	u32 status1;
803 	u32 status2;
804 	int i;
805 	int ch;
806 	struct coh901318_base *base  = dev_id;
807 	struct coh901318_chan *cohc;
808 	void __iomem *virtbase = base->virtbase;
809 
810 	status1 = readl(virtbase + COH901318_INT_STATUS1);
811 	status2 = readl(virtbase + COH901318_INT_STATUS2);
812 
813 	if (unlikely(status1 == 0 && status2 == 0)) {
814 		dev_warn(base->dev, "spurious DMA IRQ from no channel!\n");
815 		return IRQ_HANDLED;
816 	}
817 
818 	/* TODO: consider handle IRQ in tasklet here to
819 	 *       minimize interrupt latency */
820 
821 	/* Check the first 32 DMA channels for IRQ */
822 	while (status1) {
823 		/* Find first bit set, return as a number. */
824 		i = ffs(status1) - 1;
825 		ch = i;
826 
827 		cohc = &base->chans[ch];
828 		spin_lock(&cohc->lock);
829 
830 		/* Mask off this bit */
831 		status1 &= ~(1 << i);
832 		/* Check the individual channel bits */
833 		if (test_bit(i, virtbase + COH901318_BE_INT_STATUS1)) {
834 			dev_crit(COHC_2_DEV(cohc),
835 				 "DMA bus error on channel %d!\n", ch);
836 			BUG_ON(1);
837 			/* Clear BE interrupt */
838 			__set_bit(i, virtbase + COH901318_BE_INT_CLEAR1);
839 		} else {
840 			/* Caused by TC, really? */
841 			if (unlikely(!test_bit(i, virtbase +
842 					       COH901318_TC_INT_STATUS1))) {
843 				dev_warn(COHC_2_DEV(cohc),
844 					 "ignoring interrupt not caused by terminal count on channel %d\n", ch);
845 				/* Clear TC interrupt */
846 				BUG_ON(1);
847 				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
848 			} else {
849 				/* Enable powersave if transfer has finished */
850 				if (!(readl(virtbase + COH901318_CX_STAT +
851 					    COH901318_CX_STAT_SPACING*ch) &
852 				      COH901318_CX_STAT_ENABLED)) {
853 					enable_powersave(cohc);
854 				}
855 
856 				/* Must clear TC interrupt before calling
857 				 * dma_tc_handle
858 				 * in case tc_handle initiate a new dma job
859 				 */
860 				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
861 
862 				dma_tc_handle(cohc);
863 			}
864 		}
865 		spin_unlock(&cohc->lock);
866 	}
867 
868 	/* Check the remaining 32 DMA channels for IRQ */
869 	while (status2) {
870 		/* Find first bit set, return as a number. */
871 		i = ffs(status2) - 1;
872 		ch = i + 32;
873 		cohc = &base->chans[ch];
874 		spin_lock(&cohc->lock);
875 
876 		/* Mask off this bit */
877 		status2 &= ~(1 << i);
878 		/* Check the individual channel bits */
879 		if (test_bit(i, virtbase + COH901318_BE_INT_STATUS2)) {
880 			dev_crit(COHC_2_DEV(cohc),
881 				 "DMA bus error on channel %d!\n", ch);
882 			/* Clear BE interrupt */
883 			BUG_ON(1);
884 			__set_bit(i, virtbase + COH901318_BE_INT_CLEAR2);
885 		} else {
886 			/* Caused by TC, really? */
887 			if (unlikely(!test_bit(i, virtbase +
888 					       COH901318_TC_INT_STATUS2))) {
889 				dev_warn(COHC_2_DEV(cohc),
890 					 "ignoring interrupt not caused by terminal count on channel %d\n", ch);
891 				/* Clear TC interrupt */
892 				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
893 				BUG_ON(1);
894 			} else {
895 				/* Enable powersave if transfer has finished */
896 				if (!(readl(virtbase + COH901318_CX_STAT +
897 					    COH901318_CX_STAT_SPACING*ch) &
898 				      COH901318_CX_STAT_ENABLED)) {
899 					enable_powersave(cohc);
900 				}
901 				/* Must clear TC interrupt before calling
902 				 * dma_tc_handle
903 				 * in case tc_handle initiate a new dma job
904 				 */
905 				__set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
906 
907 				dma_tc_handle(cohc);
908 			}
909 		}
910 		spin_unlock(&cohc->lock);
911 	}
912 
913 	return IRQ_HANDLED;
914 }
915 
coh901318_alloc_chan_resources(struct dma_chan * chan)916 static int coh901318_alloc_chan_resources(struct dma_chan *chan)
917 {
918 	struct coh901318_chan	*cohc = to_coh901318_chan(chan);
919 	unsigned long flags;
920 
921 	dev_vdbg(COHC_2_DEV(cohc), "[%s] DMA channel %d\n",
922 		 __func__, cohc->id);
923 
924 	if (chan->client_count > 1)
925 		return -EBUSY;
926 
927 	spin_lock_irqsave(&cohc->lock, flags);
928 
929 	coh901318_config(cohc, NULL);
930 
931 	cohc->allocated = 1;
932 	cohc->completed = chan->cookie = 1;
933 
934 	spin_unlock_irqrestore(&cohc->lock, flags);
935 
936 	return 1;
937 }
938 
939 static void
coh901318_free_chan_resources(struct dma_chan * chan)940 coh901318_free_chan_resources(struct dma_chan *chan)
941 {
942 	struct coh901318_chan	*cohc = to_coh901318_chan(chan);
943 	int channel = cohc->id;
944 	unsigned long flags;
945 
946 	spin_lock_irqsave(&cohc->lock, flags);
947 
948 	/* Disable HW */
949 	writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CFG +
950 	       COH901318_CX_CFG_SPACING*channel);
951 	writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CTRL +
952 	       COH901318_CX_CTRL_SPACING*channel);
953 
954 	cohc->allocated = 0;
955 
956 	spin_unlock_irqrestore(&cohc->lock, flags);
957 
958 	chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
959 }
960 
961 
962 static dma_cookie_t
coh901318_tx_submit(struct dma_async_tx_descriptor * tx)963 coh901318_tx_submit(struct dma_async_tx_descriptor *tx)
964 {
965 	struct coh901318_desc *cohd = container_of(tx, struct coh901318_desc,
966 						   desc);
967 	struct coh901318_chan *cohc = to_coh901318_chan(tx->chan);
968 	unsigned long flags;
969 
970 	spin_lock_irqsave(&cohc->lock, flags);
971 
972 	tx->cookie = coh901318_assign_cookie(cohc, cohd);
973 
974 	coh901318_desc_queue(cohc, cohd);
975 
976 	spin_unlock_irqrestore(&cohc->lock, flags);
977 
978 	return tx->cookie;
979 }
980 
981 static struct dma_async_tx_descriptor *
coh901318_prep_memcpy(struct dma_chan * chan,dma_addr_t dest,dma_addr_t src,size_t size,unsigned long flags)982 coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
983 		      size_t size, unsigned long flags)
984 {
985 	struct coh901318_lli *lli;
986 	struct coh901318_desc *cohd;
987 	unsigned long flg;
988 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
989 	int lli_len;
990 	u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
991 	int ret;
992 
993 	spin_lock_irqsave(&cohc->lock, flg);
994 
995 	dev_vdbg(COHC_2_DEV(cohc),
996 		 "[%s] channel %d src 0x%x dest 0x%x size %d\n",
997 		 __func__, cohc->id, src, dest, size);
998 
999 	if (flags & DMA_PREP_INTERRUPT)
1000 		/* Trigger interrupt after last lli */
1001 		ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
1002 
1003 	lli_len = size >> MAX_DMA_PACKET_SIZE_SHIFT;
1004 	if ((lli_len << MAX_DMA_PACKET_SIZE_SHIFT) < size)
1005 		lli_len++;
1006 
1007 	lli = coh901318_lli_alloc(&cohc->base->pool, lli_len);
1008 
1009 	if (lli == NULL)
1010 		goto err;
1011 
1012 	ret = coh901318_lli_fill_memcpy(
1013 		&cohc->base->pool, lli, src, size, dest,
1014 		cohc_chan_param(cohc)->ctrl_lli_chained,
1015 		ctrl_last);
1016 	if (ret)
1017 		goto err;
1018 
1019 	COH_DBG(coh901318_list_print(cohc, lli));
1020 
1021 	/* Pick a descriptor to handle this transfer */
1022 	cohd = coh901318_desc_get(cohc);
1023 	cohd->lli = lli;
1024 	cohd->flags = flags;
1025 	cohd->desc.tx_submit = coh901318_tx_submit;
1026 
1027 	spin_unlock_irqrestore(&cohc->lock, flg);
1028 
1029 	return &cohd->desc;
1030  err:
1031 	spin_unlock_irqrestore(&cohc->lock, flg);
1032 	return NULL;
1033 }
1034 
1035 static struct dma_async_tx_descriptor *
coh901318_prep_slave_sg(struct dma_chan * chan,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction direction,unsigned long flags)1036 coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
1037 			unsigned int sg_len, enum dma_transfer_direction direction,
1038 			unsigned long flags)
1039 {
1040 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1041 	struct coh901318_lli *lli;
1042 	struct coh901318_desc *cohd;
1043 	const struct coh901318_params *params;
1044 	struct scatterlist *sg;
1045 	int len = 0;
1046 	int size;
1047 	int i;
1048 	u32 ctrl_chained = cohc_chan_param(cohc)->ctrl_lli_chained;
1049 	u32 ctrl = cohc_chan_param(cohc)->ctrl_lli;
1050 	u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
1051 	u32 config;
1052 	unsigned long flg;
1053 	int ret;
1054 
1055 	if (!sgl)
1056 		goto out;
1057 	if (sgl->length == 0)
1058 		goto out;
1059 
1060 	spin_lock_irqsave(&cohc->lock, flg);
1061 
1062 	dev_vdbg(COHC_2_DEV(cohc), "[%s] sg_len %d dir %d\n",
1063 		 __func__, sg_len, direction);
1064 
1065 	if (flags & DMA_PREP_INTERRUPT)
1066 		/* Trigger interrupt after last lli */
1067 		ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
1068 
1069 	params = cohc_chan_param(cohc);
1070 	config = params->config;
1071 	/*
1072 	 * Add runtime-specific control on top, make
1073 	 * sure the bits you set per peripheral channel are
1074 	 * cleared in the default config from the platform.
1075 	 */
1076 	ctrl_chained |= cohc->runtime_ctrl;
1077 	ctrl_last |= cohc->runtime_ctrl;
1078 	ctrl |= cohc->runtime_ctrl;
1079 
1080 	if (direction == DMA_MEM_TO_DEV) {
1081 		u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
1082 			COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE;
1083 
1084 		config |= COH901318_CX_CFG_RM_MEMORY_TO_PRIMARY;
1085 		ctrl_chained |= tx_flags;
1086 		ctrl_last |= tx_flags;
1087 		ctrl |= tx_flags;
1088 	} else if (direction == DMA_DEV_TO_MEM) {
1089 		u32 rx_flags = COH901318_CX_CTRL_PRDD_DEST |
1090 			COH901318_CX_CTRL_DST_ADDR_INC_ENABLE;
1091 
1092 		config |= COH901318_CX_CFG_RM_PRIMARY_TO_MEMORY;
1093 		ctrl_chained |= rx_flags;
1094 		ctrl_last |= rx_flags;
1095 		ctrl |= rx_flags;
1096 	} else
1097 		goto err_direction;
1098 
1099 	/* The dma only supports transmitting packages up to
1100 	 * MAX_DMA_PACKET_SIZE. Calculate to total number of
1101 	 * dma elemts required to send the entire sg list
1102 	 */
1103 	for_each_sg(sgl, sg, sg_len, i) {
1104 		unsigned int factor;
1105 		size = sg_dma_len(sg);
1106 
1107 		if (size <= MAX_DMA_PACKET_SIZE) {
1108 			len++;
1109 			continue;
1110 		}
1111 
1112 		factor = size >> MAX_DMA_PACKET_SIZE_SHIFT;
1113 		if ((factor << MAX_DMA_PACKET_SIZE_SHIFT) < size)
1114 			factor++;
1115 
1116 		len += factor;
1117 	}
1118 
1119 	pr_debug("Allocate %d lli:s for this transfer\n", len);
1120 	lli = coh901318_lli_alloc(&cohc->base->pool, len);
1121 
1122 	if (lli == NULL)
1123 		goto err_dma_alloc;
1124 
1125 	/* initiate allocated lli list */
1126 	ret = coh901318_lli_fill_sg(&cohc->base->pool, lli, sgl, sg_len,
1127 				    cohc_dev_addr(cohc),
1128 				    ctrl_chained,
1129 				    ctrl,
1130 				    ctrl_last,
1131 				    direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
1132 	if (ret)
1133 		goto err_lli_fill;
1134 
1135 
1136 	COH_DBG(coh901318_list_print(cohc, lli));
1137 
1138 	/* Pick a descriptor to handle this transfer */
1139 	cohd = coh901318_desc_get(cohc);
1140 	cohd->head_config = config;
1141 	/*
1142 	 * Set the default head ctrl for the channel to the one from the
1143 	 * lli, things may have changed due to odd buffer alignment
1144 	 * etc.
1145 	 */
1146 	cohd->head_ctrl = lli->control;
1147 	cohd->dir = direction;
1148 	cohd->flags = flags;
1149 	cohd->desc.tx_submit = coh901318_tx_submit;
1150 	cohd->lli = lli;
1151 
1152 	spin_unlock_irqrestore(&cohc->lock, flg);
1153 
1154 	return &cohd->desc;
1155  err_lli_fill:
1156  err_dma_alloc:
1157  err_direction:
1158 	spin_unlock_irqrestore(&cohc->lock, flg);
1159  out:
1160 	return NULL;
1161 }
1162 
1163 static enum dma_status
coh901318_tx_status(struct dma_chan * chan,dma_cookie_t cookie,struct dma_tx_state * txstate)1164 coh901318_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
1165 		 struct dma_tx_state *txstate)
1166 {
1167 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1168 	dma_cookie_t last_used;
1169 	dma_cookie_t last_complete;
1170 	int ret;
1171 
1172 	last_complete = cohc->completed;
1173 	last_used = chan->cookie;
1174 
1175 	ret = dma_async_is_complete(cookie, last_complete, last_used);
1176 
1177 	dma_set_tx_state(txstate, last_complete, last_used,
1178 			 coh901318_get_bytes_left(chan));
1179 	if (ret == DMA_IN_PROGRESS && cohc->stopped)
1180 		ret = DMA_PAUSED;
1181 
1182 	return ret;
1183 }
1184 
1185 static void
coh901318_issue_pending(struct dma_chan * chan)1186 coh901318_issue_pending(struct dma_chan *chan)
1187 {
1188 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1189 	unsigned long flags;
1190 
1191 	spin_lock_irqsave(&cohc->lock, flags);
1192 
1193 	/*
1194 	 * Busy means that pending jobs are already being processed,
1195 	 * and then there is no point in starting the queue: the
1196 	 * terminal count interrupt on the channel will take the next
1197 	 * job on the queue and execute it anyway.
1198 	 */
1199 	if (!cohc->busy)
1200 		coh901318_queue_start(cohc);
1201 
1202 	spin_unlock_irqrestore(&cohc->lock, flags);
1203 }
1204 
1205 /*
1206  * Here we wrap in the runtime dma control interface
1207  */
1208 struct burst_table {
1209 	int burst_8bit;
1210 	int burst_16bit;
1211 	int burst_32bit;
1212 	u32 reg;
1213 };
1214 
1215 static const struct burst_table burst_sizes[] = {
1216 	{
1217 		.burst_8bit = 64,
1218 		.burst_16bit = 32,
1219 		.burst_32bit = 16,
1220 		.reg = COH901318_CX_CTRL_BURST_COUNT_64_BYTES,
1221 	},
1222 	{
1223 		.burst_8bit = 48,
1224 		.burst_16bit = 24,
1225 		.burst_32bit = 12,
1226 		.reg = COH901318_CX_CTRL_BURST_COUNT_48_BYTES,
1227 	},
1228 	{
1229 		.burst_8bit = 32,
1230 		.burst_16bit = 16,
1231 		.burst_32bit = 8,
1232 		.reg = COH901318_CX_CTRL_BURST_COUNT_32_BYTES,
1233 	},
1234 	{
1235 		.burst_8bit = 16,
1236 		.burst_16bit = 8,
1237 		.burst_32bit = 4,
1238 		.reg = COH901318_CX_CTRL_BURST_COUNT_16_BYTES,
1239 	},
1240 	{
1241 		.burst_8bit = 8,
1242 		.burst_16bit = 4,
1243 		.burst_32bit = 2,
1244 		.reg = COH901318_CX_CTRL_BURST_COUNT_8_BYTES,
1245 	},
1246 	{
1247 		.burst_8bit = 4,
1248 		.burst_16bit = 2,
1249 		.burst_32bit = 1,
1250 		.reg = COH901318_CX_CTRL_BURST_COUNT_4_BYTES,
1251 	},
1252 	{
1253 		.burst_8bit = 2,
1254 		.burst_16bit = 1,
1255 		.burst_32bit = 0,
1256 		.reg = COH901318_CX_CTRL_BURST_COUNT_2_BYTES,
1257 	},
1258 	{
1259 		.burst_8bit = 1,
1260 		.burst_16bit = 0,
1261 		.burst_32bit = 0,
1262 		.reg = COH901318_CX_CTRL_BURST_COUNT_1_BYTE,
1263 	},
1264 };
1265 
coh901318_dma_set_runtimeconfig(struct dma_chan * chan,struct dma_slave_config * config)1266 static void coh901318_dma_set_runtimeconfig(struct dma_chan *chan,
1267 			struct dma_slave_config *config)
1268 {
1269 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1270 	dma_addr_t addr;
1271 	enum dma_slave_buswidth addr_width;
1272 	u32 maxburst;
1273 	u32 runtime_ctrl = 0;
1274 	int i = 0;
1275 
1276 	/* We only support mem to per or per to mem transfers */
1277 	if (config->direction == DMA_DEV_TO_MEM) {
1278 		addr = config->src_addr;
1279 		addr_width = config->src_addr_width;
1280 		maxburst = config->src_maxburst;
1281 	} else if (config->direction == DMA_MEM_TO_DEV) {
1282 		addr = config->dst_addr;
1283 		addr_width = config->dst_addr_width;
1284 		maxburst = config->dst_maxburst;
1285 	} else {
1286 		dev_err(COHC_2_DEV(cohc), "illegal channel mode\n");
1287 		return;
1288 	}
1289 
1290 	dev_dbg(COHC_2_DEV(cohc), "configure channel for %d byte transfers\n",
1291 		addr_width);
1292 	switch (addr_width)  {
1293 	case DMA_SLAVE_BUSWIDTH_1_BYTE:
1294 		runtime_ctrl |=
1295 			COH901318_CX_CTRL_SRC_BUS_SIZE_8_BITS |
1296 			COH901318_CX_CTRL_DST_BUS_SIZE_8_BITS;
1297 
1298 		while (i < ARRAY_SIZE(burst_sizes)) {
1299 			if (burst_sizes[i].burst_8bit <= maxburst)
1300 				break;
1301 			i++;
1302 		}
1303 
1304 		break;
1305 	case DMA_SLAVE_BUSWIDTH_2_BYTES:
1306 		runtime_ctrl |=
1307 			COH901318_CX_CTRL_SRC_BUS_SIZE_16_BITS |
1308 			COH901318_CX_CTRL_DST_BUS_SIZE_16_BITS;
1309 
1310 		while (i < ARRAY_SIZE(burst_sizes)) {
1311 			if (burst_sizes[i].burst_16bit <= maxburst)
1312 				break;
1313 			i++;
1314 		}
1315 
1316 		break;
1317 	case DMA_SLAVE_BUSWIDTH_4_BYTES:
1318 		/* Direction doesn't matter here, it's 32/32 bits */
1319 		runtime_ctrl |=
1320 			COH901318_CX_CTRL_SRC_BUS_SIZE_32_BITS |
1321 			COH901318_CX_CTRL_DST_BUS_SIZE_32_BITS;
1322 
1323 		while (i < ARRAY_SIZE(burst_sizes)) {
1324 			if (burst_sizes[i].burst_32bit <= maxburst)
1325 				break;
1326 			i++;
1327 		}
1328 
1329 		break;
1330 	default:
1331 		dev_err(COHC_2_DEV(cohc),
1332 			"bad runtimeconfig: alien address width\n");
1333 		return;
1334 	}
1335 
1336 	runtime_ctrl |= burst_sizes[i].reg;
1337 	dev_dbg(COHC_2_DEV(cohc),
1338 		"selected burst size %d bytes for address width %d bytes, maxburst %d\n",
1339 		burst_sizes[i].burst_8bit, addr_width, maxburst);
1340 
1341 	cohc->runtime_addr = addr;
1342 	cohc->runtime_ctrl = runtime_ctrl;
1343 }
1344 
1345 static int
coh901318_control(struct dma_chan * chan,enum dma_ctrl_cmd cmd,unsigned long arg)1346 coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
1347 		  unsigned long arg)
1348 {
1349 	unsigned long flags;
1350 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
1351 	struct coh901318_desc *cohd;
1352 	void __iomem *virtbase = cohc->base->virtbase;
1353 
1354 	if (cmd == DMA_SLAVE_CONFIG) {
1355 		struct dma_slave_config *config =
1356 			(struct dma_slave_config *) arg;
1357 
1358 		coh901318_dma_set_runtimeconfig(chan, config);
1359 		return 0;
1360 	  }
1361 
1362 	if (cmd == DMA_PAUSE) {
1363 		coh901318_pause(chan);
1364 		return 0;
1365 	}
1366 
1367 	if (cmd == DMA_RESUME) {
1368 		coh901318_resume(chan);
1369 		return 0;
1370 	}
1371 
1372 	if (cmd != DMA_TERMINATE_ALL)
1373 		return -ENXIO;
1374 
1375 	/* The remainder of this function terminates the transfer */
1376 	coh901318_pause(chan);
1377 	spin_lock_irqsave(&cohc->lock, flags);
1378 
1379 	/* Clear any pending BE or TC interrupt */
1380 	if (cohc->id < 32) {
1381 		writel(1 << cohc->id, virtbase + COH901318_BE_INT_CLEAR1);
1382 		writel(1 << cohc->id, virtbase + COH901318_TC_INT_CLEAR1);
1383 	} else {
1384 		writel(1 << (cohc->id - 32), virtbase +
1385 		       COH901318_BE_INT_CLEAR2);
1386 		writel(1 << (cohc->id - 32), virtbase +
1387 		       COH901318_TC_INT_CLEAR2);
1388 	}
1389 
1390 	enable_powersave(cohc);
1391 
1392 	while ((cohd = coh901318_first_active_get(cohc))) {
1393 		/* release the lli allocation*/
1394 		coh901318_lli_free(&cohc->base->pool, &cohd->lli);
1395 
1396 		/* return desc to free-list */
1397 		coh901318_desc_remove(cohd);
1398 		coh901318_desc_free(cohc, cohd);
1399 	}
1400 
1401 	while ((cohd = coh901318_first_queued(cohc))) {
1402 		/* release the lli allocation*/
1403 		coh901318_lli_free(&cohc->base->pool, &cohd->lli);
1404 
1405 		/* return desc to free-list */
1406 		coh901318_desc_remove(cohd);
1407 		coh901318_desc_free(cohc, cohd);
1408 	}
1409 
1410 
1411 	cohc->nbr_active_done = 0;
1412 	cohc->busy = 0;
1413 
1414 	spin_unlock_irqrestore(&cohc->lock, flags);
1415 
1416 	return 0;
1417 }
1418 
coh901318_base_init(struct dma_device * dma,const int * pick_chans,struct coh901318_base * base)1419 void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
1420 			 struct coh901318_base *base)
1421 {
1422 	int chans_i;
1423 	int i = 0;
1424 	struct coh901318_chan *cohc;
1425 
1426 	INIT_LIST_HEAD(&dma->channels);
1427 
1428 	for (chans_i = 0; pick_chans[chans_i] != -1; chans_i += 2) {
1429 		for (i = pick_chans[chans_i]; i <= pick_chans[chans_i+1]; i++) {
1430 			cohc = &base->chans[i];
1431 
1432 			cohc->base = base;
1433 			cohc->chan.device = dma;
1434 			cohc->id = i;
1435 
1436 			/* TODO: do we really need this lock if only one
1437 			 * client is connected to each channel?
1438 			 */
1439 
1440 			spin_lock_init(&cohc->lock);
1441 
1442 			cohc->nbr_active_done = 0;
1443 			cohc->busy = 0;
1444 			INIT_LIST_HEAD(&cohc->free);
1445 			INIT_LIST_HEAD(&cohc->active);
1446 			INIT_LIST_HEAD(&cohc->queue);
1447 
1448 			tasklet_init(&cohc->tasklet, dma_tasklet,
1449 				     (unsigned long) cohc);
1450 
1451 			list_add_tail(&cohc->chan.device_node,
1452 				      &dma->channels);
1453 		}
1454 	}
1455 }
1456 
coh901318_probe(struct platform_device * pdev)1457 static int __init coh901318_probe(struct platform_device *pdev)
1458 {
1459 	int err = 0;
1460 	struct coh901318_platform *pdata;
1461 	struct coh901318_base *base;
1462 	int irq;
1463 	struct resource *io;
1464 
1465 	io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1466 	if (!io)
1467 		goto err_get_resource;
1468 
1469 	/* Map DMA controller registers to virtual memory */
1470 	if (request_mem_region(io->start,
1471 			       resource_size(io),
1472 			       pdev->dev.driver->name) == NULL) {
1473 		err = -EBUSY;
1474 		goto err_request_mem;
1475 	}
1476 
1477 	pdata = pdev->dev.platform_data;
1478 	if (!pdata)
1479 		goto err_no_platformdata;
1480 
1481 	base = kmalloc(ALIGN(sizeof(struct coh901318_base), 4) +
1482 		       pdata->max_channels *
1483 		       sizeof(struct coh901318_chan),
1484 		       GFP_KERNEL);
1485 	if (!base)
1486 		goto err_alloc_coh_dma_channels;
1487 
1488 	base->chans = ((void *)base) + ALIGN(sizeof(struct coh901318_base), 4);
1489 
1490 	base->virtbase = ioremap(io->start, resource_size(io));
1491 	if (!base->virtbase) {
1492 		err = -ENOMEM;
1493 		goto err_no_ioremap;
1494 	}
1495 
1496 	base->dev = &pdev->dev;
1497 	base->platform = pdata;
1498 	spin_lock_init(&base->pm.lock);
1499 	base->pm.started_channels = 0;
1500 
1501 	COH901318_DEBUGFS_ASSIGN(debugfs_dma_base, base);
1502 
1503 	platform_set_drvdata(pdev, base);
1504 
1505 	irq = platform_get_irq(pdev, 0);
1506 	if (irq < 0)
1507 		goto err_no_irq;
1508 
1509 	err = request_irq(irq, dma_irq_handler, IRQF_DISABLED,
1510 			  "coh901318", base);
1511 	if (err) {
1512 		dev_crit(&pdev->dev,
1513 			 "Cannot allocate IRQ for DMA controller!\n");
1514 		goto err_request_irq;
1515 	}
1516 
1517 	err = coh901318_pool_create(&base->pool, &pdev->dev,
1518 				    sizeof(struct coh901318_lli),
1519 				    32);
1520 	if (err)
1521 		goto err_pool_create;
1522 
1523 	/* init channels for device transfers */
1524 	coh901318_base_init(&base->dma_slave,  base->platform->chans_slave,
1525 			    base);
1526 
1527 	dma_cap_zero(base->dma_slave.cap_mask);
1528 	dma_cap_set(DMA_SLAVE, base->dma_slave.cap_mask);
1529 
1530 	base->dma_slave.device_alloc_chan_resources = coh901318_alloc_chan_resources;
1531 	base->dma_slave.device_free_chan_resources = coh901318_free_chan_resources;
1532 	base->dma_slave.device_prep_slave_sg = coh901318_prep_slave_sg;
1533 	base->dma_slave.device_tx_status = coh901318_tx_status;
1534 	base->dma_slave.device_issue_pending = coh901318_issue_pending;
1535 	base->dma_slave.device_control = coh901318_control;
1536 	base->dma_slave.dev = &pdev->dev;
1537 
1538 	err = dma_async_device_register(&base->dma_slave);
1539 
1540 	if (err)
1541 		goto err_register_slave;
1542 
1543 	/* init channels for memcpy */
1544 	coh901318_base_init(&base->dma_memcpy, base->platform->chans_memcpy,
1545 			    base);
1546 
1547 	dma_cap_zero(base->dma_memcpy.cap_mask);
1548 	dma_cap_set(DMA_MEMCPY, base->dma_memcpy.cap_mask);
1549 
1550 	base->dma_memcpy.device_alloc_chan_resources = coh901318_alloc_chan_resources;
1551 	base->dma_memcpy.device_free_chan_resources = coh901318_free_chan_resources;
1552 	base->dma_memcpy.device_prep_dma_memcpy = coh901318_prep_memcpy;
1553 	base->dma_memcpy.device_tx_status = coh901318_tx_status;
1554 	base->dma_memcpy.device_issue_pending = coh901318_issue_pending;
1555 	base->dma_memcpy.device_control = coh901318_control;
1556 	base->dma_memcpy.dev = &pdev->dev;
1557 	/*
1558 	 * This controller can only access address at even 32bit boundaries,
1559 	 * i.e. 2^2
1560 	 */
1561 	base->dma_memcpy.copy_align = 2;
1562 	err = dma_async_device_register(&base->dma_memcpy);
1563 
1564 	if (err)
1565 		goto err_register_memcpy;
1566 
1567 	dev_info(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n",
1568 		(u32) base->virtbase);
1569 
1570 	return err;
1571 
1572  err_register_memcpy:
1573 	dma_async_device_unregister(&base->dma_slave);
1574  err_register_slave:
1575 	coh901318_pool_destroy(&base->pool);
1576  err_pool_create:
1577 	free_irq(platform_get_irq(pdev, 0), base);
1578  err_request_irq:
1579  err_no_irq:
1580 	iounmap(base->virtbase);
1581  err_no_ioremap:
1582 	kfree(base);
1583  err_alloc_coh_dma_channels:
1584  err_no_platformdata:
1585 	release_mem_region(pdev->resource->start,
1586 			   resource_size(pdev->resource));
1587  err_request_mem:
1588  err_get_resource:
1589 	return err;
1590 }
1591 
coh901318_remove(struct platform_device * pdev)1592 static int __exit coh901318_remove(struct platform_device *pdev)
1593 {
1594 	struct coh901318_base *base = platform_get_drvdata(pdev);
1595 
1596 	dma_async_device_unregister(&base->dma_memcpy);
1597 	dma_async_device_unregister(&base->dma_slave);
1598 	coh901318_pool_destroy(&base->pool);
1599 	free_irq(platform_get_irq(pdev, 0), base);
1600 	iounmap(base->virtbase);
1601 	kfree(base);
1602 	release_mem_region(pdev->resource->start,
1603 			   resource_size(pdev->resource));
1604 	return 0;
1605 }
1606 
1607 
1608 static struct platform_driver coh901318_driver = {
1609 	.remove = __exit_p(coh901318_remove),
1610 	.driver = {
1611 		.name	= "coh901318",
1612 	},
1613 };
1614 
coh901318_init(void)1615 int __init coh901318_init(void)
1616 {
1617 	return platform_driver_probe(&coh901318_driver, coh901318_probe);
1618 }
1619 subsys_initcall(coh901318_init);
1620 
coh901318_exit(void)1621 void __exit coh901318_exit(void)
1622 {
1623 	platform_driver_unregister(&coh901318_driver);
1624 }
1625 module_exit(coh901318_exit);
1626 
1627 MODULE_LICENSE("GPL");
1628 MODULE_AUTHOR("Per Friden");
1629