xref: /openbmc/u-boot/drivers/dma/bcm6348-iudma.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
4  *
5  * Derived from linux/drivers/dma/bcm63xx-iudma.c:
6  *	Copyright (C) 2015 Simon Arlott <simon@fire.lp0.eu>
7  *
8  * Derived from linux/drivers/net/ethernet/broadcom/bcm63xx_enet.c:
9  *	Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
10  *
11  * Derived from bcm963xx_4.12L.06B_consumer/shared/opensource/include/bcm963xx/63268_map_part.h:
12  *	Copyright (C) 2000-2010 Broadcom Corporation
13  *
14  * Derived from bcm963xx_4.12L.06B_consumer/bcmdrivers/opensource/net/enet/impl4/bcmenet.c:
15  *	Copyright (C) 2010 Broadcom Corporation
16  */
17 
18 #include <common.h>
19 #include <clk.h>
20 #include <dm.h>
21 #include <dma-uclass.h>
22 #include <memalign.h>
23 #include <reset.h>
24 #include <asm/io.h>
25 
26 #define DMA_RX_DESC	6
27 #define DMA_TX_DESC	1
28 
29 /* DMA Channels */
30 #define DMA_CHAN_FLOWC(x)		((x) >> 1)
31 #define DMA_CHAN_MAX			16
32 #define DMA_CHAN_SIZE			0x10
33 #define DMA_CHAN_TOUT			500
34 
35 /* DMA Global Configuration register */
36 #define DMA_CFG_REG			0x00
37 #define  DMA_CFG_ENABLE_SHIFT		0
38 #define  DMA_CFG_ENABLE_MASK		(1 << DMA_CFG_ENABLE_SHIFT)
39 #define  DMA_CFG_FLOWC_ENABLE(x)	BIT(DMA_CHAN_FLOWC(x) + 1)
40 #define  DMA_CFG_NCHANS_SHIFT		24
41 #define  DMA_CFG_NCHANS_MASK		(0xf << DMA_CFG_NCHANS_SHIFT)
42 
43 /* DMA Global Flow Control registers */
44 #define DMA_FLOWC_THR_LO_REG(x)		(0x04 + DMA_CHAN_FLOWC(x) * 0x0c)
45 #define DMA_FLOWC_THR_HI_REG(x)		(0x08 + DMA_CHAN_FLOWC(x) * 0x0c)
46 #define DMA_FLOWC_ALLOC_REG(x)		(0x0c + DMA_CHAN_FLOWC(x) * 0x0c)
47 #define  DMA_FLOWC_ALLOC_FORCE_SHIFT	31
48 #define  DMA_FLOWC_ALLOC_FORCE_MASK	(1 << DMA_FLOWC_ALLOC_FORCE_SHIFT)
49 
50 /* DMA Global Reset register */
51 #define DMA_RST_REG			0x34
52 #define  DMA_RST_CHAN_SHIFT		0
53 #define  DMA_RST_CHAN_MASK(x)		(1 << x)
54 
55 /* DMA Channel Configuration register */
56 #define DMAC_CFG_REG(x)			(DMA_CHAN_SIZE * (x) + 0x00)
57 #define  DMAC_CFG_ENABLE_SHIFT		0
58 #define  DMAC_CFG_ENABLE_MASK		(1 << DMAC_CFG_ENABLE_SHIFT)
59 #define  DMAC_CFG_PKT_HALT_SHIFT	1
60 #define  DMAC_CFG_PKT_HALT_MASK		(1 << DMAC_CFG_PKT_HALT_SHIFT)
61 #define  DMAC_CFG_BRST_HALT_SHIFT	2
62 #define  DMAC_CFG_BRST_HALT_MASK	(1 << DMAC_CFG_BRST_HALT_SHIFT)
63 
64 /* DMA Channel Max Burst Length register */
65 #define DMAC_BURST_REG(x)		(DMA_CHAN_SIZE * (x) + 0x0c)
66 
67 /* DMA SRAM Descriptor Ring Start register */
68 #define DMAS_RSTART_REG(x)		(DMA_CHAN_SIZE * (x) + 0x00)
69 
70 /* DMA SRAM State/Bytes done/ring offset register */
71 #define DMAS_STATE_DATA_REG(x)		(DMA_CHAN_SIZE * (x) + 0x04)
72 
73 /* DMA SRAM Buffer Descriptor status and length register */
74 #define DMAS_DESC_LEN_STATUS_REG(x)	(DMA_CHAN_SIZE * (x) + 0x08)
75 
76 /* DMA SRAM Buffer Descriptor status and length register */
77 #define DMAS_DESC_BASE_BUFPTR_REG(x)	(DMA_CHAN_SIZE * (x) + 0x0c)
78 
79 /* DMA Descriptor Status */
80 #define DMAD_ST_CRC_SHIFT		8
81 #define DMAD_ST_CRC_MASK		(1 << DMAD_ST_CRC_SHIFT)
82 #define DMAD_ST_WRAP_SHIFT		12
83 #define DMAD_ST_WRAP_MASK		(1 << DMAD_ST_WRAP_SHIFT)
84 #define DMAD_ST_SOP_SHIFT		13
85 #define DMAD_ST_SOP_MASK		(1 << DMAD_ST_SOP_SHIFT)
86 #define DMAD_ST_EOP_SHIFT		14
87 #define DMAD_ST_EOP_MASK		(1 << DMAD_ST_EOP_SHIFT)
88 #define DMAD_ST_OWN_SHIFT		15
89 #define DMAD_ST_OWN_MASK		(1 << DMAD_ST_OWN_SHIFT)
90 
91 #define DMAD6348_ST_OV_ERR_SHIFT	0
92 #define DMAD6348_ST_OV_ERR_MASK		(1 << DMAD6348_ST_OV_ERR_SHIFT)
93 #define DMAD6348_ST_CRC_ERR_SHIFT	1
94 #define DMAD6348_ST_CRC_ERR_MASK	(1 << DMAD6348_ST_CRC_ERR_SHIFT)
95 #define DMAD6348_ST_RX_ERR_SHIFT	2
96 #define DMAD6348_ST_RX_ERR_MASK		(1 << DMAD6348_ST_RX_ERR_SHIFT)
97 #define DMAD6348_ST_OS_ERR_SHIFT	4
98 #define DMAD6348_ST_OS_ERR_MASK		(1 << DMAD6348_ST_OS_ERR_SHIFT)
99 #define DMAD6348_ST_UN_ERR_SHIFT	9
100 #define DMAD6348_ST_UN_ERR_MASK		(1 << DMAD6348_ST_UN_ERR_SHIFT)
101 
102 struct bcm6348_dma_desc {
103 	uint16_t length;
104 	uint16_t status;
105 	uint32_t address;
106 };
107 
108 struct bcm6348_chan_priv {
109 	void __iomem *dma_ring;
110 	uint8_t dma_ring_size;
111 	uint8_t desc_id;
112 	uint8_t desc_cnt;
113 	bool *busy_desc;
114 	bool running;
115 };
116 
117 struct bcm6348_iudma_hw {
118 	uint16_t err_mask;
119 };
120 
121 struct bcm6348_iudma_priv {
122 	const struct bcm6348_iudma_hw *hw;
123 	void __iomem *base;
124 	void __iomem *chan;
125 	void __iomem *sram;
126 	struct bcm6348_chan_priv **ch_priv;
127 	uint8_t n_channels;
128 };
129 
130 static inline bool bcm6348_iudma_chan_is_rx(uint8_t ch)
131 {
132 	return !(ch & 1);
133 }
134 
135 static inline void bcm6348_iudma_fdc(void *ptr, ulong size)
136 {
137 	ulong start = (ulong) ptr;
138 
139 	flush_dcache_range(start, start + size);
140 }
141 
142 static inline void bcm6348_iudma_idc(void *ptr, ulong size)
143 {
144 	ulong start = (ulong) ptr;
145 
146 	invalidate_dcache_range(start, start + size);
147 }
148 
149 static void bcm6348_iudma_chan_stop(struct bcm6348_iudma_priv *priv,
150 				    uint8_t ch)
151 {
152 	unsigned int timeout = DMA_CHAN_TOUT;
153 
154 	do {
155 		uint32_t cfg, halt;
156 
157 		if (timeout > DMA_CHAN_TOUT / 2)
158 			halt = DMAC_CFG_PKT_HALT_MASK;
159 		else
160 			halt = DMAC_CFG_BRST_HALT_MASK;
161 
162 		/* try to stop dma channel */
163 		writel_be(halt, priv->chan + DMAC_CFG_REG(ch));
164 		mb();
165 
166 		/* check if channel was stopped */
167 		cfg = readl_be(priv->chan + DMAC_CFG_REG(ch));
168 		if (!(cfg & DMAC_CFG_ENABLE_MASK))
169 			break;
170 
171 		udelay(1);
172 	} while (--timeout);
173 
174 	if (!timeout)
175 		pr_err("unable to stop channel %u\n", ch);
176 
177 	/* reset dma channel */
178 	setbits_be32(priv->base + DMA_RST_REG, DMA_RST_CHAN_MASK(ch));
179 	mb();
180 	clrbits_be32(priv->base + DMA_RST_REG, DMA_RST_CHAN_MASK(ch));
181 }
182 
183 static int bcm6348_iudma_disable(struct dma *dma)
184 {
185 	struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
186 	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
187 
188 	/* stop dma channel */
189 	bcm6348_iudma_chan_stop(priv, dma->id);
190 
191 	/* dma flow control */
192 	if (bcm6348_iudma_chan_is_rx(dma->id))
193 		writel_be(DMA_FLOWC_ALLOC_FORCE_MASK,
194 			  DMA_FLOWC_ALLOC_REG(dma->id));
195 
196 	/* init channel config */
197 	ch_priv->running = false;
198 	ch_priv->desc_id = 0;
199 	if (bcm6348_iudma_chan_is_rx(dma->id))
200 		ch_priv->desc_cnt = 0;
201 	else
202 		ch_priv->desc_cnt = ch_priv->dma_ring_size;
203 
204 	return 0;
205 }
206 
207 static int bcm6348_iudma_enable(struct dma *dma)
208 {
209 	const struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
210 	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
211 	struct bcm6348_dma_desc *dma_desc = ch_priv->dma_ring;
212 	uint8_t i;
213 
214 	/* dma ring init */
215 	for (i = 0; i < ch_priv->desc_cnt; i++) {
216 		if (bcm6348_iudma_chan_is_rx(dma->id)) {
217 			ch_priv->busy_desc[i] = false;
218 			dma_desc->status |= DMAD_ST_OWN_MASK;
219 		} else {
220 			dma_desc->status = 0;
221 			dma_desc->length = 0;
222 			dma_desc->address = 0;
223 		}
224 
225 		if (i == ch_priv->desc_cnt - 1)
226 			dma_desc->status |= DMAD_ST_WRAP_MASK;
227 
228 		dma_desc++;
229 	}
230 
231 	/* init to first descriptor */
232 	ch_priv->desc_id = 0;
233 
234 	/* force cache writeback */
235 	bcm6348_iudma_fdc(ch_priv->dma_ring,
236 			  sizeof(*dma_desc) * ch_priv->desc_cnt);
237 
238 	/* clear sram */
239 	writel_be(0, priv->sram + DMAS_STATE_DATA_REG(dma->id));
240 	writel_be(0, priv->sram + DMAS_DESC_LEN_STATUS_REG(dma->id));
241 	writel_be(0, priv->sram + DMAS_DESC_BASE_BUFPTR_REG(dma->id));
242 
243 	/* set dma ring start */
244 	writel_be(virt_to_phys(ch_priv->dma_ring),
245 		  priv->sram + DMAS_RSTART_REG(dma->id));
246 
247 	/* set flow control */
248 	if (bcm6348_iudma_chan_is_rx(dma->id)) {
249 		u32 val;
250 
251 		setbits_be32(priv->base + DMA_CFG_REG,
252 			     DMA_CFG_FLOWC_ENABLE(dma->id));
253 
254 		val = ch_priv->desc_cnt / 3;
255 		writel_be(val, priv->base + DMA_FLOWC_THR_LO_REG(dma->id));
256 
257 		val = (ch_priv->desc_cnt * 2) / 3;
258 		writel_be(val, priv->base + DMA_FLOWC_THR_HI_REG(dma->id));
259 
260 		writel_be(0, priv->base + DMA_FLOWC_ALLOC_REG(dma->id));
261 	}
262 
263 	/* set dma max burst */
264 	writel_be(ch_priv->desc_cnt,
265 		  priv->chan + DMAC_BURST_REG(dma->id));
266 
267 	/* kick rx dma channel */
268 	if (bcm6348_iudma_chan_is_rx(dma->id))
269 		setbits_be32(priv->chan + DMAC_CFG_REG(dma->id),
270 			     DMAC_CFG_ENABLE_MASK);
271 
272 	/* channel is now enabled */
273 	ch_priv->running = true;
274 
275 	return 0;
276 }
277 
278 static int bcm6348_iudma_request(struct dma *dma)
279 {
280 	const struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
281 	struct bcm6348_chan_priv *ch_priv;
282 
283 	/* check if channel is valid */
284 	if (dma->id >= priv->n_channels)
285 		return -ENODEV;
286 
287 	/* alloc channel private data */
288 	priv->ch_priv[dma->id] = calloc(1, sizeof(struct bcm6348_chan_priv));
289 	if (!priv->ch_priv[dma->id])
290 		return -ENOMEM;
291 	ch_priv = priv->ch_priv[dma->id];
292 
293 	/* alloc dma ring */
294 	if (bcm6348_iudma_chan_is_rx(dma->id))
295 		ch_priv->dma_ring_size = DMA_RX_DESC;
296 	else
297 		ch_priv->dma_ring_size = DMA_TX_DESC;
298 
299 	ch_priv->dma_ring =
300 		malloc_cache_aligned(sizeof(struct bcm6348_dma_desc) *
301 				     ch_priv->dma_ring_size);
302 	if (!ch_priv->dma_ring)
303 		return -ENOMEM;
304 
305 	/* init channel config */
306 	ch_priv->running = false;
307 	ch_priv->desc_id = 0;
308 	if (bcm6348_iudma_chan_is_rx(dma->id)) {
309 		ch_priv->desc_cnt = 0;
310 		ch_priv->busy_desc = calloc(ch_priv->desc_cnt, sizeof(bool));
311 	} else {
312 		ch_priv->desc_cnt = ch_priv->dma_ring_size;
313 		ch_priv->busy_desc = NULL;
314 	}
315 
316 	return 0;
317 }
318 
319 static int bcm6348_iudma_receive(struct dma *dma, void **dst, void *metadata)
320 {
321 	const struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
322 	const struct bcm6348_iudma_hw *hw = priv->hw;
323 	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
324 	struct bcm6348_dma_desc *dma_desc = dma_desc = ch_priv->dma_ring;
325 	int ret;
326 
327 	/* get dma ring descriptor address */
328 	dma_desc += ch_priv->desc_id;
329 
330 	/* invalidate cache data */
331 	bcm6348_iudma_idc(dma_desc, sizeof(*dma_desc));
332 
333 	/* check dma own */
334 	if (dma_desc->status & DMAD_ST_OWN_MASK)
335 		return -EAGAIN;
336 
337 	/* check pkt */
338 	if (!(dma_desc->status & DMAD_ST_EOP_MASK) ||
339 	    !(dma_desc->status & DMAD_ST_SOP_MASK) ||
340 	    (dma_desc->status & hw->err_mask)) {
341 		pr_err("invalid pkt received (ch=%ld desc=%u) (st=%04x)\n",
342 		       dma->id, ch_priv->desc_id, dma_desc->status);
343 		ret = -EAGAIN;
344 	} else {
345 		/* set dma buffer address */
346 		*dst = phys_to_virt(dma_desc->address);
347 
348 		/* invalidate cache data */
349 		bcm6348_iudma_idc(*dst, dma_desc->length);
350 
351 		/* return packet length */
352 		ret = dma_desc->length;
353 	}
354 
355 	/* busy dma descriptor */
356 	ch_priv->busy_desc[ch_priv->desc_id] = true;
357 
358 	/* increment dma descriptor */
359 	ch_priv->desc_id = (ch_priv->desc_id + 1) % ch_priv->desc_cnt;
360 
361 	return ret;
362 }
363 
364 static int bcm6348_iudma_send(struct dma *dma, void *src, size_t len,
365 			      void *metadata)
366 {
367 	const struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
368 	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
369 	struct bcm6348_dma_desc *dma_desc;
370 	uint16_t status;
371 
372 	/* flush cache */
373 	bcm6348_iudma_fdc(src, len);
374 
375 	/* get dma ring descriptor address */
376 	dma_desc = ch_priv->dma_ring;
377 	dma_desc += ch_priv->desc_id;
378 
379 	/* config dma descriptor */
380 	status = (DMAD_ST_OWN_MASK |
381 		  DMAD_ST_EOP_MASK |
382 		  DMAD_ST_CRC_MASK |
383 		  DMAD_ST_SOP_MASK);
384 	if (ch_priv->desc_id == ch_priv->desc_cnt - 1)
385 		status |= DMAD_ST_WRAP_MASK;
386 
387 	/* set dma descriptor */
388 	dma_desc->address = virt_to_phys(src);
389 	dma_desc->length = len;
390 	dma_desc->status = status;
391 
392 	/* flush cache */
393 	bcm6348_iudma_fdc(dma_desc, sizeof(*dma_desc));
394 
395 	/* kick tx dma channel */
396 	setbits_be32(priv->chan + DMAC_CFG_REG(dma->id), DMAC_CFG_ENABLE_MASK);
397 
398 	/* poll dma status */
399 	do {
400 		/* invalidate cache */
401 		bcm6348_iudma_idc(dma_desc, sizeof(*dma_desc));
402 
403 		if (!(dma_desc->status & DMAD_ST_OWN_MASK))
404 			break;
405 	} while(1);
406 
407 	/* increment dma descriptor */
408 	ch_priv->desc_id = (ch_priv->desc_id + 1) % ch_priv->desc_cnt;
409 
410 	return 0;
411 }
412 
413 static int bcm6348_iudma_free_rcv_buf(struct dma *dma, void *dst, size_t size)
414 {
415 	const struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
416 	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
417 	struct bcm6348_dma_desc *dma_desc = ch_priv->dma_ring;
418 	uint16_t status;
419 	uint8_t i;
420 	u32 cfg;
421 
422 	/* get dirty dma descriptor */
423 	for (i = 0; i < ch_priv->desc_cnt; i++) {
424 		if (phys_to_virt(dma_desc->address) == dst)
425 			break;
426 
427 		dma_desc++;
428 	}
429 
430 	/* dma descriptor not found */
431 	if (i == ch_priv->desc_cnt) {
432 		pr_err("dirty dma descriptor not found\n");
433 		return -ENOENT;
434 	}
435 
436 	/* invalidate cache */
437 	bcm6348_iudma_idc(ch_priv->dma_ring,
438 			  sizeof(*dma_desc) * ch_priv->desc_cnt);
439 
440 	/* free dma descriptor */
441 	ch_priv->busy_desc[i] = false;
442 
443 	status = DMAD_ST_OWN_MASK;
444 	if (i == ch_priv->desc_cnt - 1)
445 		status |= DMAD_ST_WRAP_MASK;
446 
447 	dma_desc->status |= status;
448 	dma_desc->length = PKTSIZE_ALIGN;
449 
450 	/* tell dma we allocated one buffer */
451 	writel_be(1, DMA_FLOWC_ALLOC_REG(dma->id));
452 
453 	/* flush cache */
454 	bcm6348_iudma_fdc(ch_priv->dma_ring,
455 			  sizeof(*dma_desc) * ch_priv->desc_cnt);
456 
457 	/* kick rx dma channel if disabled */
458 	cfg = readl_be(priv->chan + DMAC_CFG_REG(dma->id));
459 	if (!(cfg & DMAC_CFG_ENABLE_MASK))
460 		setbits_be32(priv->chan + DMAC_CFG_REG(dma->id),
461 			     DMAC_CFG_ENABLE_MASK);
462 
463 	return 0;
464 }
465 
466 static int bcm6348_iudma_add_rcv_buf(struct dma *dma, void *dst, size_t size)
467 {
468 	const struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
469 	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
470 	struct bcm6348_dma_desc *dma_desc = ch_priv->dma_ring;
471 
472 	/* no more dma descriptors available */
473 	if (ch_priv->desc_cnt == ch_priv->dma_ring_size) {
474 		pr_err("max number of buffers reached\n");
475 		return -EINVAL;
476 	}
477 
478 	/* get next dma descriptor */
479 	dma_desc += ch_priv->desc_cnt;
480 
481 	/* init dma descriptor */
482 	dma_desc->address = virt_to_phys(dst);
483 	dma_desc->length = size;
484 	dma_desc->status = 0;
485 
486 	/* flush cache */
487 	bcm6348_iudma_fdc(dma_desc, sizeof(*dma_desc));
488 
489 	/* increment dma descriptors */
490 	ch_priv->desc_cnt++;
491 
492 	return 0;
493 }
494 
495 static int bcm6348_iudma_prepare_rcv_buf(struct dma *dma, void *dst,
496 					 size_t size)
497 {
498 	const struct bcm6348_iudma_priv *priv = dev_get_priv(dma->dev);
499 	struct bcm6348_chan_priv *ch_priv = priv->ch_priv[dma->id];
500 
501 	/* only add new rx buffers if channel isn't running */
502 	if (ch_priv->running)
503 		return bcm6348_iudma_free_rcv_buf(dma, dst, size);
504 	else
505 		return bcm6348_iudma_add_rcv_buf(dma, dst, size);
506 }
507 
508 static const struct dma_ops bcm6348_iudma_ops = {
509 	.disable = bcm6348_iudma_disable,
510 	.enable = bcm6348_iudma_enable,
511 	.prepare_rcv_buf = bcm6348_iudma_prepare_rcv_buf,
512 	.request = bcm6348_iudma_request,
513 	.receive = bcm6348_iudma_receive,
514 	.send = bcm6348_iudma_send,
515 };
516 
517 static const struct bcm6348_iudma_hw bcm6348_hw = {
518 	.err_mask = (DMAD6348_ST_OV_ERR_MASK |
519 		     DMAD6348_ST_CRC_ERR_MASK |
520 		     DMAD6348_ST_RX_ERR_MASK |
521 		     DMAD6348_ST_OS_ERR_MASK |
522 		     DMAD6348_ST_UN_ERR_MASK),
523 };
524 
525 static const struct bcm6348_iudma_hw bcm6368_hw = {
526 	.err_mask = 0,
527 };
528 
529 static const struct udevice_id bcm6348_iudma_ids[] = {
530 	{
531 		.compatible = "brcm,bcm6348-iudma",
532 		.data = (ulong)&bcm6348_hw,
533 	}, {
534 		.compatible = "brcm,bcm6368-iudma",
535 		.data = (ulong)&bcm6368_hw,
536 	}, { /* sentinel */ }
537 };
538 
539 static int bcm6348_iudma_probe(struct udevice *dev)
540 {
541 	struct dma_dev_priv *uc_priv = dev_get_uclass_priv(dev);
542 	struct bcm6348_iudma_priv *priv = dev_get_priv(dev);
543 	const struct bcm6348_iudma_hw *hw =
544 		(const struct bcm6348_iudma_hw *)dev_get_driver_data(dev);
545 	uint8_t ch;
546 	int i;
547 
548 	uc_priv->supported = (DMA_SUPPORTS_DEV_TO_MEM |
549 			      DMA_SUPPORTS_MEM_TO_DEV);
550 	priv->hw = hw;
551 
552 	/* dma global base address */
553 	priv->base = dev_remap_addr_name(dev, "dma");
554 	if (!priv->base)
555 		return -EINVAL;
556 
557 	/* dma channels base address */
558 	priv->chan = dev_remap_addr_name(dev, "dma-channels");
559 	if (!priv->chan)
560 		return -EINVAL;
561 
562 	/* dma sram base address */
563 	priv->sram = dev_remap_addr_name(dev, "dma-sram");
564 	if (!priv->sram)
565 		return -EINVAL;
566 
567 	/* get number of channels */
568 	priv->n_channels = dev_read_u32_default(dev, "dma-channels", 8);
569 	if (priv->n_channels > DMA_CHAN_MAX)
570 		return -EINVAL;
571 
572 	/* try to enable clocks */
573 	for (i = 0; ; i++) {
574 		struct clk clk;
575 		int ret;
576 
577 		ret = clk_get_by_index(dev, i, &clk);
578 		if (ret < 0)
579 			break;
580 
581 		ret = clk_enable(&clk);
582 		if (ret < 0) {
583 			pr_err("error enabling clock %d\n", i);
584 			return ret;
585 		}
586 
587 		ret = clk_free(&clk);
588 		if (ret < 0) {
589 			pr_err("error freeing clock %d\n", i);
590 			return ret;
591 		}
592 	}
593 
594 	/* try to perform resets */
595 	for (i = 0; ; i++) {
596 		struct reset_ctl reset;
597 		int ret;
598 
599 		ret = reset_get_by_index(dev, i, &reset);
600 		if (ret < 0)
601 			break;
602 
603 		ret = reset_deassert(&reset);
604 		if (ret < 0) {
605 			pr_err("error deasserting reset %d\n", i);
606 			return ret;
607 		}
608 
609 		ret = reset_free(&reset);
610 		if (ret < 0) {
611 			pr_err("error freeing reset %d\n", i);
612 			return ret;
613 		}
614 	}
615 
616 	/* disable dma controller */
617 	clrbits_be32(priv->base + DMA_CFG_REG, DMA_CFG_ENABLE_MASK);
618 
619 	/* alloc channel private data pointers */
620 	priv->ch_priv = calloc(priv->n_channels,
621 			       sizeof(struct bcm6348_chan_priv*));
622 	if (!priv->ch_priv)
623 		return -ENOMEM;
624 
625 	/* stop dma channels */
626 	for (ch = 0; ch < priv->n_channels; ch++)
627 		bcm6348_iudma_chan_stop(priv, ch);
628 
629 	/* enable dma controller */
630 	setbits_be32(priv->base + DMA_CFG_REG, DMA_CFG_ENABLE_MASK);
631 
632 	return 0;
633 }
634 
635 U_BOOT_DRIVER(bcm6348_iudma) = {
636 	.name = "bcm6348_iudma",
637 	.id = UCLASS_DMA,
638 	.of_match = bcm6348_iudma_ids,
639 	.ops = &bcm6348_iudma_ops,
640 	.priv_auto_alloc_size = sizeof(struct bcm6348_iudma_priv),
641 	.probe = bcm6348_iudma_probe,
642 };
643