1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * DMA driver for Altera mSGDMA IP core
4 *
5 * Copyright (C) 2017 Stefan Roese <sr@denx.de>
6 *
7 * Based on drivers/dma/xilinx/zynqmp_dma.c, which is:
8 * Copyright (C) 2016 Xilinx, Inc. All rights reserved.
9 */
10
11 #include <linux/bitops.h>
12 #include <linux/delay.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/dmapool.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/iopoll.h>
19 #include <linux/module.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <linux/of_dma.h>
23
24 #include "dmaengine.h"
25
26 #define MSGDMA_MAX_TRANS_LEN U32_MAX
27 #define MSGDMA_DESC_NUM 1024
28
29 /**
30 * struct msgdma_extended_desc - implements an extended descriptor
31 * @read_addr_lo: data buffer source address low bits
32 * @write_addr_lo: data buffer destination address low bits
33 * @len: the number of bytes to transfer per descriptor
34 * @burst_seq_num: bit 31:24 write burst
35 * bit 23:16 read burst
36 * bit 15:00 sequence number
37 * @stride: bit 31:16 write stride
38 * bit 15:00 read stride
39 * @read_addr_hi: data buffer source address high bits
40 * @write_addr_hi: data buffer destination address high bits
41 * @control: characteristics of the transfer
42 */
43 struct msgdma_extended_desc {
44 u32 read_addr_lo;
45 u32 write_addr_lo;
46 u32 len;
47 u32 burst_seq_num;
48 u32 stride;
49 u32 read_addr_hi;
50 u32 write_addr_hi;
51 u32 control;
52 };
53
54 /* mSGDMA descriptor control field bit definitions */
55 #define MSGDMA_DESC_CTL_SET_CH(x) ((x) & 0xff)
56 #define MSGDMA_DESC_CTL_GEN_SOP BIT(8)
57 #define MSGDMA_DESC_CTL_GEN_EOP BIT(9)
58 #define MSGDMA_DESC_CTL_PARK_READS BIT(10)
59 #define MSGDMA_DESC_CTL_PARK_WRITES BIT(11)
60 #define MSGDMA_DESC_CTL_END_ON_EOP BIT(12)
61 #define MSGDMA_DESC_CTL_END_ON_LEN BIT(13)
62 #define MSGDMA_DESC_CTL_TR_COMP_IRQ BIT(14)
63 #define MSGDMA_DESC_CTL_EARLY_IRQ BIT(15)
64 #define MSGDMA_DESC_CTL_TR_ERR_IRQ GENMASK(23, 16)
65 #define MSGDMA_DESC_CTL_EARLY_DONE BIT(24)
66
67 /*
68 * Writing "1" the "go" bit commits the entire descriptor into the
69 * descriptor FIFO(s)
70 */
71 #define MSGDMA_DESC_CTL_GO BIT(31)
72
73 /* Tx buffer control flags */
74 #define MSGDMA_DESC_CTL_TX_FIRST (MSGDMA_DESC_CTL_GEN_SOP | \
75 MSGDMA_DESC_CTL_TR_ERR_IRQ | \
76 MSGDMA_DESC_CTL_GO)
77
78 #define MSGDMA_DESC_CTL_TX_MIDDLE (MSGDMA_DESC_CTL_TR_ERR_IRQ | \
79 MSGDMA_DESC_CTL_GO)
80
81 #define MSGDMA_DESC_CTL_TX_LAST (MSGDMA_DESC_CTL_GEN_EOP | \
82 MSGDMA_DESC_CTL_TR_COMP_IRQ | \
83 MSGDMA_DESC_CTL_TR_ERR_IRQ | \
84 MSGDMA_DESC_CTL_GO)
85
86 #define MSGDMA_DESC_CTL_TX_SINGLE (MSGDMA_DESC_CTL_GEN_SOP | \
87 MSGDMA_DESC_CTL_GEN_EOP | \
88 MSGDMA_DESC_CTL_TR_COMP_IRQ | \
89 MSGDMA_DESC_CTL_TR_ERR_IRQ | \
90 MSGDMA_DESC_CTL_GO)
91
92 #define MSGDMA_DESC_CTL_RX_SINGLE (MSGDMA_DESC_CTL_END_ON_EOP | \
93 MSGDMA_DESC_CTL_END_ON_LEN | \
94 MSGDMA_DESC_CTL_TR_COMP_IRQ | \
95 MSGDMA_DESC_CTL_EARLY_IRQ | \
96 MSGDMA_DESC_CTL_TR_ERR_IRQ | \
97 MSGDMA_DESC_CTL_GO)
98
99 /* mSGDMA extended descriptor stride definitions */
100 #define MSGDMA_DESC_STRIDE_RD 0x00000001
101 #define MSGDMA_DESC_STRIDE_WR 0x00010000
102 #define MSGDMA_DESC_STRIDE_RW 0x00010001
103
104 /* mSGDMA dispatcher control and status register map */
105 #define MSGDMA_CSR_STATUS 0x00 /* Read / Clear */
106 #define MSGDMA_CSR_CONTROL 0x04 /* Read / Write */
107 #define MSGDMA_CSR_RW_FILL_LEVEL 0x08 /* 31:16 - write fill level */
108 /* 15:00 - read fill level */
109 #define MSGDMA_CSR_RESP_FILL_LEVEL 0x0c /* response FIFO fill level */
110 #define MSGDMA_CSR_RW_SEQ_NUM 0x10 /* 31:16 - write seq number */
111 /* 15:00 - read seq number */
112
113 /* mSGDMA CSR status register bit definitions */
114 #define MSGDMA_CSR_STAT_BUSY BIT(0)
115 #define MSGDMA_CSR_STAT_DESC_BUF_EMPTY BIT(1)
116 #define MSGDMA_CSR_STAT_DESC_BUF_FULL BIT(2)
117 #define MSGDMA_CSR_STAT_RESP_BUF_EMPTY BIT(3)
118 #define MSGDMA_CSR_STAT_RESP_BUF_FULL BIT(4)
119 #define MSGDMA_CSR_STAT_STOPPED BIT(5)
120 #define MSGDMA_CSR_STAT_RESETTING BIT(6)
121 #define MSGDMA_CSR_STAT_STOPPED_ON_ERR BIT(7)
122 #define MSGDMA_CSR_STAT_STOPPED_ON_EARLY BIT(8)
123 #define MSGDMA_CSR_STAT_IRQ BIT(9)
124 #define MSGDMA_CSR_STAT_MASK GENMASK(9, 0)
125 #define MSGDMA_CSR_STAT_MASK_WITHOUT_IRQ GENMASK(8, 0)
126
127 #define DESC_EMPTY (MSGDMA_CSR_STAT_DESC_BUF_EMPTY | \
128 MSGDMA_CSR_STAT_RESP_BUF_EMPTY)
129
130 /* mSGDMA CSR control register bit definitions */
131 #define MSGDMA_CSR_CTL_STOP BIT(0)
132 #define MSGDMA_CSR_CTL_RESET BIT(1)
133 #define MSGDMA_CSR_CTL_STOP_ON_ERR BIT(2)
134 #define MSGDMA_CSR_CTL_STOP_ON_EARLY BIT(3)
135 #define MSGDMA_CSR_CTL_GLOBAL_INTR BIT(4)
136 #define MSGDMA_CSR_CTL_STOP_DESCS BIT(5)
137
138 /* mSGDMA CSR fill level bits */
139 #define MSGDMA_CSR_WR_FILL_LEVEL_GET(v) (((v) & 0xffff0000) >> 16)
140 #define MSGDMA_CSR_RD_FILL_LEVEL_GET(v) ((v) & 0x0000ffff)
141 #define MSGDMA_CSR_RESP_FILL_LEVEL_GET(v) ((v) & 0x0000ffff)
142
143 #define MSGDMA_CSR_SEQ_NUM_GET(v) (((v) & 0xffff0000) >> 16)
144
145 /* mSGDMA response register map */
146 #define MSGDMA_RESP_BYTES_TRANSFERRED 0x00
147 #define MSGDMA_RESP_STATUS 0x04
148
149 /* mSGDMA response register bit definitions */
150 #define MSGDMA_RESP_EARLY_TERM BIT(8)
151 #define MSGDMA_RESP_ERR_MASK 0xff
152
153 /**
154 * struct msgdma_sw_desc - implements a sw descriptor
155 * @async_tx: support for the async_tx api
156 * @hw_desc: assosiated HW descriptor
157 * @node: node to move from the free list to the tx list
158 * @tx_list: transmit list node
159 */
160 struct msgdma_sw_desc {
161 struct dma_async_tx_descriptor async_tx;
162 struct msgdma_extended_desc hw_desc;
163 struct list_head node;
164 struct list_head tx_list;
165 };
166
167 /*
168 * struct msgdma_device - DMA device structure
169 */
170 struct msgdma_device {
171 spinlock_t lock;
172 struct device *dev;
173 struct tasklet_struct irq_tasklet;
174 struct list_head pending_list;
175 struct list_head free_list;
176 struct list_head active_list;
177 struct list_head done_list;
178 u32 desc_free_cnt;
179 bool idle;
180
181 struct dma_device dmadev;
182 struct dma_chan dmachan;
183 dma_addr_t hw_desq;
184 struct msgdma_sw_desc *sw_desq;
185 unsigned int npendings;
186
187 struct dma_slave_config slave_cfg;
188
189 int irq;
190
191 /* mSGDMA controller */
192 void __iomem *csr;
193
194 /* mSGDMA descriptors */
195 void __iomem *desc;
196
197 /* mSGDMA response */
198 void __iomem *resp;
199 };
200
201 #define to_mdev(chan) container_of(chan, struct msgdma_device, dmachan)
202 #define tx_to_desc(tx) container_of(tx, struct msgdma_sw_desc, async_tx)
203
204 /**
205 * msgdma_get_descriptor - Get the sw descriptor from the pool
206 * @mdev: Pointer to the Altera mSGDMA device structure
207 *
208 * Return: The sw descriptor
209 */
msgdma_get_descriptor(struct msgdma_device * mdev)210 static struct msgdma_sw_desc *msgdma_get_descriptor(struct msgdma_device *mdev)
211 {
212 struct msgdma_sw_desc *desc;
213 unsigned long flags;
214
215 spin_lock_irqsave(&mdev->lock, flags);
216 desc = list_first_entry(&mdev->free_list, struct msgdma_sw_desc, node);
217 list_del(&desc->node);
218 spin_unlock_irqrestore(&mdev->lock, flags);
219
220 INIT_LIST_HEAD(&desc->tx_list);
221
222 return desc;
223 }
224
225 /**
226 * msgdma_free_descriptor - Issue pending transactions
227 * @mdev: Pointer to the Altera mSGDMA device structure
228 * @desc: Transaction descriptor pointer
229 */
msgdma_free_descriptor(struct msgdma_device * mdev,struct msgdma_sw_desc * desc)230 static void msgdma_free_descriptor(struct msgdma_device *mdev,
231 struct msgdma_sw_desc *desc)
232 {
233 struct msgdma_sw_desc *child, *next;
234
235 mdev->desc_free_cnt++;
236 list_move_tail(&desc->node, &mdev->free_list);
237 list_for_each_entry_safe(child, next, &desc->tx_list, node) {
238 mdev->desc_free_cnt++;
239 list_move_tail(&child->node, &mdev->free_list);
240 }
241 }
242
243 /**
244 * msgdma_free_desc_list - Free descriptors list
245 * @mdev: Pointer to the Altera mSGDMA device structure
246 * @list: List to parse and delete the descriptor
247 */
msgdma_free_desc_list(struct msgdma_device * mdev,struct list_head * list)248 static void msgdma_free_desc_list(struct msgdma_device *mdev,
249 struct list_head *list)
250 {
251 struct msgdma_sw_desc *desc, *next;
252
253 list_for_each_entry_safe(desc, next, list, node)
254 msgdma_free_descriptor(mdev, desc);
255 }
256
257 /**
258 * msgdma_desc_config - Configure the descriptor
259 * @desc: Hw descriptor pointer
260 * @dst: Destination buffer address
261 * @src: Source buffer address
262 * @len: Transfer length
263 * @stride: Read/write stride value to set
264 */
msgdma_desc_config(struct msgdma_extended_desc * desc,dma_addr_t dst,dma_addr_t src,size_t len,u32 stride)265 static void msgdma_desc_config(struct msgdma_extended_desc *desc,
266 dma_addr_t dst, dma_addr_t src, size_t len,
267 u32 stride)
268 {
269 /* Set lower 32bits of src & dst addresses in the descriptor */
270 desc->read_addr_lo = lower_32_bits(src);
271 desc->write_addr_lo = lower_32_bits(dst);
272
273 /* Set upper 32bits of src & dst addresses in the descriptor */
274 desc->read_addr_hi = upper_32_bits(src);
275 desc->write_addr_hi = upper_32_bits(dst);
276
277 desc->len = len;
278 desc->stride = stride;
279 desc->burst_seq_num = 0; /* 0 will result in max burst length */
280
281 /*
282 * Don't set interrupt on xfer end yet, this will be done later
283 * for the "last" descriptor
284 */
285 desc->control = MSGDMA_DESC_CTL_TR_ERR_IRQ | MSGDMA_DESC_CTL_GO |
286 MSGDMA_DESC_CTL_END_ON_LEN;
287 }
288
289 /**
290 * msgdma_desc_config_eod - Mark the descriptor as end descriptor
291 * @desc: Hw descriptor pointer
292 */
msgdma_desc_config_eod(struct msgdma_extended_desc * desc)293 static void msgdma_desc_config_eod(struct msgdma_extended_desc *desc)
294 {
295 desc->control |= MSGDMA_DESC_CTL_TR_COMP_IRQ;
296 }
297
298 /**
299 * msgdma_tx_submit - Submit DMA transaction
300 * @tx: Async transaction descriptor pointer
301 *
302 * Return: cookie value
303 */
msgdma_tx_submit(struct dma_async_tx_descriptor * tx)304 static dma_cookie_t msgdma_tx_submit(struct dma_async_tx_descriptor *tx)
305 {
306 struct msgdma_device *mdev = to_mdev(tx->chan);
307 struct msgdma_sw_desc *new;
308 dma_cookie_t cookie;
309 unsigned long flags;
310
311 new = tx_to_desc(tx);
312 spin_lock_irqsave(&mdev->lock, flags);
313 cookie = dma_cookie_assign(tx);
314
315 list_add_tail(&new->node, &mdev->pending_list);
316 spin_unlock_irqrestore(&mdev->lock, flags);
317
318 return cookie;
319 }
320
321 /**
322 * msgdma_prep_memcpy - prepare descriptors for memcpy transaction
323 * @dchan: DMA channel
324 * @dma_dst: Destination buffer address
325 * @dma_src: Source buffer address
326 * @len: Transfer length
327 * @flags: transfer ack flags
328 *
329 * Return: Async transaction descriptor on success and NULL on failure
330 */
331 static struct dma_async_tx_descriptor *
msgdma_prep_memcpy(struct dma_chan * dchan,dma_addr_t dma_dst,dma_addr_t dma_src,size_t len,ulong flags)332 msgdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst,
333 dma_addr_t dma_src, size_t len, ulong flags)
334 {
335 struct msgdma_device *mdev = to_mdev(dchan);
336 struct msgdma_sw_desc *new, *first = NULL;
337 struct msgdma_extended_desc *desc;
338 size_t copy;
339 u32 desc_cnt;
340 unsigned long irqflags;
341
342 desc_cnt = DIV_ROUND_UP(len, MSGDMA_MAX_TRANS_LEN);
343
344 spin_lock_irqsave(&mdev->lock, irqflags);
345 if (desc_cnt > mdev->desc_free_cnt) {
346 spin_unlock_irqrestore(&mdev->lock, irqflags);
347 dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev);
348 return NULL;
349 }
350 mdev->desc_free_cnt -= desc_cnt;
351 spin_unlock_irqrestore(&mdev->lock, irqflags);
352
353 do {
354 /* Allocate and populate the descriptor */
355 new = msgdma_get_descriptor(mdev);
356
357 copy = min_t(size_t, len, MSGDMA_MAX_TRANS_LEN);
358 desc = &new->hw_desc;
359 msgdma_desc_config(desc, dma_dst, dma_src, copy,
360 MSGDMA_DESC_STRIDE_RW);
361 len -= copy;
362 dma_src += copy;
363 dma_dst += copy;
364 if (!first)
365 first = new;
366 else
367 list_add_tail(&new->node, &first->tx_list);
368 } while (len);
369
370 msgdma_desc_config_eod(desc);
371 async_tx_ack(&first->async_tx);
372 first->async_tx.flags = flags;
373
374 return &first->async_tx;
375 }
376
377 /**
378 * msgdma_prep_slave_sg - prepare descriptors for a slave sg transaction
379 *
380 * @dchan: DMA channel
381 * @sgl: Destination scatter list
382 * @sg_len: Number of entries in destination scatter list
383 * @dir: DMA transfer direction
384 * @flags: transfer ack flags
385 * @context: transfer context (unused)
386 */
387 static struct dma_async_tx_descriptor *
msgdma_prep_slave_sg(struct dma_chan * dchan,struct scatterlist * sgl,unsigned int sg_len,enum dma_transfer_direction dir,unsigned long flags,void * context)388 msgdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
389 unsigned int sg_len, enum dma_transfer_direction dir,
390 unsigned long flags, void *context)
391
392 {
393 struct msgdma_device *mdev = to_mdev(dchan);
394 struct dma_slave_config *cfg = &mdev->slave_cfg;
395 struct msgdma_sw_desc *new, *first = NULL;
396 void *desc = NULL;
397 size_t len, avail;
398 dma_addr_t dma_dst, dma_src;
399 u32 desc_cnt = 0, i;
400 struct scatterlist *sg;
401 u32 stride;
402 unsigned long irqflags;
403
404 for_each_sg(sgl, sg, sg_len, i)
405 desc_cnt += DIV_ROUND_UP(sg_dma_len(sg), MSGDMA_MAX_TRANS_LEN);
406
407 spin_lock_irqsave(&mdev->lock, irqflags);
408 if (desc_cnt > mdev->desc_free_cnt) {
409 spin_unlock_irqrestore(&mdev->lock, irqflags);
410 dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev);
411 return NULL;
412 }
413 mdev->desc_free_cnt -= desc_cnt;
414 spin_unlock_irqrestore(&mdev->lock, irqflags);
415
416 avail = sg_dma_len(sgl);
417
418 /* Run until we are out of scatterlist entries */
419 while (true) {
420 /* Allocate and populate the descriptor */
421 new = msgdma_get_descriptor(mdev);
422
423 desc = &new->hw_desc;
424 len = min_t(size_t, avail, MSGDMA_MAX_TRANS_LEN);
425
426 if (dir == DMA_MEM_TO_DEV) {
427 dma_src = sg_dma_address(sgl) + sg_dma_len(sgl) - avail;
428 dma_dst = cfg->dst_addr;
429 stride = MSGDMA_DESC_STRIDE_RD;
430 } else {
431 dma_src = cfg->src_addr;
432 dma_dst = sg_dma_address(sgl) + sg_dma_len(sgl) - avail;
433 stride = MSGDMA_DESC_STRIDE_WR;
434 }
435 msgdma_desc_config(desc, dma_dst, dma_src, len, stride);
436 avail -= len;
437
438 if (!first)
439 first = new;
440 else
441 list_add_tail(&new->node, &first->tx_list);
442
443 /* Fetch the next scatterlist entry */
444 if (avail == 0) {
445 if (sg_len == 0)
446 break;
447 sgl = sg_next(sgl);
448 if (sgl == NULL)
449 break;
450 sg_len--;
451 avail = sg_dma_len(sgl);
452 }
453 }
454
455 msgdma_desc_config_eod(desc);
456 first->async_tx.flags = flags;
457
458 return &first->async_tx;
459 }
460
msgdma_dma_config(struct dma_chan * dchan,struct dma_slave_config * config)461 static int msgdma_dma_config(struct dma_chan *dchan,
462 struct dma_slave_config *config)
463 {
464 struct msgdma_device *mdev = to_mdev(dchan);
465
466 memcpy(&mdev->slave_cfg, config, sizeof(*config));
467
468 return 0;
469 }
470
msgdma_reset(struct msgdma_device * mdev)471 static void msgdma_reset(struct msgdma_device *mdev)
472 {
473 u32 val;
474 int ret;
475
476 /* Reset mSGDMA */
477 iowrite32(MSGDMA_CSR_STAT_MASK, mdev->csr + MSGDMA_CSR_STATUS);
478 iowrite32(MSGDMA_CSR_CTL_RESET, mdev->csr + MSGDMA_CSR_CONTROL);
479
480 ret = readl_poll_timeout(mdev->csr + MSGDMA_CSR_STATUS, val,
481 (val & MSGDMA_CSR_STAT_RESETTING) == 0,
482 1, 10000);
483 if (ret)
484 dev_err(mdev->dev, "DMA channel did not reset\n");
485
486 /* Clear all status bits */
487 iowrite32(MSGDMA_CSR_STAT_MASK, mdev->csr + MSGDMA_CSR_STATUS);
488
489 /* Enable the DMA controller including interrupts */
490 iowrite32(MSGDMA_CSR_CTL_STOP_ON_ERR | MSGDMA_CSR_CTL_STOP_ON_EARLY |
491 MSGDMA_CSR_CTL_GLOBAL_INTR, mdev->csr + MSGDMA_CSR_CONTROL);
492
493 mdev->idle = true;
494 };
495
msgdma_copy_one(struct msgdma_device * mdev,struct msgdma_sw_desc * desc)496 static void msgdma_copy_one(struct msgdma_device *mdev,
497 struct msgdma_sw_desc *desc)
498 {
499 void __iomem *hw_desc = mdev->desc;
500
501 /*
502 * Check if the DESC FIFO it not full. If its full, we need to wait
503 * for at least one entry to become free again
504 */
505 while (ioread32(mdev->csr + MSGDMA_CSR_STATUS) &
506 MSGDMA_CSR_STAT_DESC_BUF_FULL)
507 mdelay(1);
508
509 /*
510 * The descriptor needs to get copied into the descriptor FIFO
511 * of the DMA controller. The descriptor will get flushed to the
512 * FIFO, once the last word (control word) is written. Since we
513 * are not 100% sure that memcpy() writes all word in the "correct"
514 * oder (address from low to high) on all architectures, we make
515 * sure this control word is written last by single coding it and
516 * adding some write-barriers here.
517 */
518 memcpy((void __force *)hw_desc, &desc->hw_desc,
519 sizeof(desc->hw_desc) - sizeof(u32));
520
521 /* Write control word last to flush this descriptor into the FIFO */
522 mdev->idle = false;
523 wmb();
524 iowrite32(desc->hw_desc.control, hw_desc +
525 offsetof(struct msgdma_extended_desc, control));
526 wmb();
527 }
528
529 /**
530 * msgdma_copy_desc_to_fifo - copy descriptor(s) into controller FIFO
531 * @mdev: Pointer to the Altera mSGDMA device structure
532 * @desc: Transaction descriptor pointer
533 */
msgdma_copy_desc_to_fifo(struct msgdma_device * mdev,struct msgdma_sw_desc * desc)534 static void msgdma_copy_desc_to_fifo(struct msgdma_device *mdev,
535 struct msgdma_sw_desc *desc)
536 {
537 struct msgdma_sw_desc *sdesc, *next;
538
539 msgdma_copy_one(mdev, desc);
540
541 list_for_each_entry_safe(sdesc, next, &desc->tx_list, node)
542 msgdma_copy_one(mdev, sdesc);
543 }
544
545 /**
546 * msgdma_start_transfer - Initiate the new transfer
547 * @mdev: Pointer to the Altera mSGDMA device structure
548 */
msgdma_start_transfer(struct msgdma_device * mdev)549 static void msgdma_start_transfer(struct msgdma_device *mdev)
550 {
551 struct msgdma_sw_desc *desc;
552
553 if (!mdev->idle)
554 return;
555
556 desc = list_first_entry_or_null(&mdev->pending_list,
557 struct msgdma_sw_desc, node);
558 if (!desc)
559 return;
560
561 list_splice_tail_init(&mdev->pending_list, &mdev->active_list);
562 msgdma_copy_desc_to_fifo(mdev, desc);
563 }
564
565 /**
566 * msgdma_issue_pending - Issue pending transactions
567 * @chan: DMA channel pointer
568 */
msgdma_issue_pending(struct dma_chan * chan)569 static void msgdma_issue_pending(struct dma_chan *chan)
570 {
571 struct msgdma_device *mdev = to_mdev(chan);
572 unsigned long flags;
573
574 spin_lock_irqsave(&mdev->lock, flags);
575 msgdma_start_transfer(mdev);
576 spin_unlock_irqrestore(&mdev->lock, flags);
577 }
578
579 /**
580 * msgdma_chan_desc_cleanup - Cleanup the completed descriptors
581 * @mdev: Pointer to the Altera mSGDMA device structure
582 */
msgdma_chan_desc_cleanup(struct msgdma_device * mdev)583 static void msgdma_chan_desc_cleanup(struct msgdma_device *mdev)
584 {
585 struct msgdma_sw_desc *desc, *next;
586 unsigned long irqflags;
587
588 list_for_each_entry_safe(desc, next, &mdev->done_list, node) {
589 struct dmaengine_desc_callback cb;
590
591 dmaengine_desc_get_callback(&desc->async_tx, &cb);
592 if (dmaengine_desc_callback_valid(&cb)) {
593 spin_unlock_irqrestore(&mdev->lock, irqflags);
594 dmaengine_desc_callback_invoke(&cb, NULL);
595 spin_lock_irqsave(&mdev->lock, irqflags);
596 }
597
598 /* Run any dependencies, then free the descriptor */
599 msgdma_free_descriptor(mdev, desc);
600 }
601 }
602
603 /**
604 * msgdma_complete_descriptor - Mark the active descriptor as complete
605 * @mdev: Pointer to the Altera mSGDMA device structure
606 */
msgdma_complete_descriptor(struct msgdma_device * mdev)607 static void msgdma_complete_descriptor(struct msgdma_device *mdev)
608 {
609 struct msgdma_sw_desc *desc;
610
611 desc = list_first_entry_or_null(&mdev->active_list,
612 struct msgdma_sw_desc, node);
613 if (!desc)
614 return;
615 list_del(&desc->node);
616 dma_cookie_complete(&desc->async_tx);
617 list_add_tail(&desc->node, &mdev->done_list);
618 }
619
620 /**
621 * msgdma_free_descriptors - Free channel descriptors
622 * @mdev: Pointer to the Altera mSGDMA device structure
623 */
msgdma_free_descriptors(struct msgdma_device * mdev)624 static void msgdma_free_descriptors(struct msgdma_device *mdev)
625 {
626 msgdma_free_desc_list(mdev, &mdev->active_list);
627 msgdma_free_desc_list(mdev, &mdev->pending_list);
628 msgdma_free_desc_list(mdev, &mdev->done_list);
629 }
630
631 /**
632 * msgdma_free_chan_resources - Free channel resources
633 * @dchan: DMA channel pointer
634 */
msgdma_free_chan_resources(struct dma_chan * dchan)635 static void msgdma_free_chan_resources(struct dma_chan *dchan)
636 {
637 struct msgdma_device *mdev = to_mdev(dchan);
638 unsigned long flags;
639
640 spin_lock_irqsave(&mdev->lock, flags);
641 msgdma_free_descriptors(mdev);
642 spin_unlock_irqrestore(&mdev->lock, flags);
643 kfree(mdev->sw_desq);
644 }
645
646 /**
647 * msgdma_alloc_chan_resources - Allocate channel resources
648 * @dchan: DMA channel
649 *
650 * Return: Number of descriptors on success and failure value on error
651 */
msgdma_alloc_chan_resources(struct dma_chan * dchan)652 static int msgdma_alloc_chan_resources(struct dma_chan *dchan)
653 {
654 struct msgdma_device *mdev = to_mdev(dchan);
655 struct msgdma_sw_desc *desc;
656 int i;
657
658 mdev->sw_desq = kcalloc(MSGDMA_DESC_NUM, sizeof(*desc), GFP_NOWAIT);
659 if (!mdev->sw_desq)
660 return -ENOMEM;
661
662 mdev->idle = true;
663 mdev->desc_free_cnt = MSGDMA_DESC_NUM;
664
665 INIT_LIST_HEAD(&mdev->free_list);
666
667 for (i = 0; i < MSGDMA_DESC_NUM; i++) {
668 desc = mdev->sw_desq + i;
669 dma_async_tx_descriptor_init(&desc->async_tx, &mdev->dmachan);
670 desc->async_tx.tx_submit = msgdma_tx_submit;
671 list_add_tail(&desc->node, &mdev->free_list);
672 }
673
674 return MSGDMA_DESC_NUM;
675 }
676
677 /**
678 * msgdma_tasklet - Schedule completion tasklet
679 * @t: Pointer to the Altera sSGDMA channel structure
680 */
msgdma_tasklet(struct tasklet_struct * t)681 static void msgdma_tasklet(struct tasklet_struct *t)
682 {
683 struct msgdma_device *mdev = from_tasklet(mdev, t, irq_tasklet);
684 u32 count;
685 u32 __maybe_unused size;
686 u32 __maybe_unused status;
687 unsigned long flags;
688
689 spin_lock_irqsave(&mdev->lock, flags);
690
691 if (mdev->resp) {
692 /* Read number of responses that are available */
693 count = ioread32(mdev->csr + MSGDMA_CSR_RESP_FILL_LEVEL);
694 dev_dbg(mdev->dev, "%s (%d): response count=%d\n",
695 __func__, __LINE__, count);
696 } else {
697 count = 1;
698 }
699
700 while (count--) {
701 /*
702 * Read both longwords to purge this response from the FIFO
703 * On Avalon-MM implementations, size and status do not
704 * have any real values, like transferred bytes or error
705 * bits. So we need to just drop these values.
706 */
707 if (mdev->resp) {
708 size = ioread32(mdev->resp +
709 MSGDMA_RESP_BYTES_TRANSFERRED);
710 status = ioread32(mdev->resp +
711 MSGDMA_RESP_STATUS);
712 }
713
714 msgdma_complete_descriptor(mdev);
715 msgdma_chan_desc_cleanup(mdev);
716 }
717
718 spin_unlock_irqrestore(&mdev->lock, flags);
719 }
720
721 /**
722 * msgdma_irq_handler - Altera mSGDMA Interrupt handler
723 * @irq: IRQ number
724 * @data: Pointer to the Altera mSGDMA device structure
725 *
726 * Return: IRQ_HANDLED/IRQ_NONE
727 */
msgdma_irq_handler(int irq,void * data)728 static irqreturn_t msgdma_irq_handler(int irq, void *data)
729 {
730 struct msgdma_device *mdev = data;
731 u32 status;
732
733 status = ioread32(mdev->csr + MSGDMA_CSR_STATUS);
734 if ((status & MSGDMA_CSR_STAT_BUSY) == 0) {
735 /* Start next transfer if the DMA controller is idle */
736 spin_lock(&mdev->lock);
737 mdev->idle = true;
738 msgdma_start_transfer(mdev);
739 spin_unlock(&mdev->lock);
740 }
741
742 tasklet_schedule(&mdev->irq_tasklet);
743
744 /* Clear interrupt in mSGDMA controller */
745 iowrite32(MSGDMA_CSR_STAT_IRQ, mdev->csr + MSGDMA_CSR_STATUS);
746
747 return IRQ_HANDLED;
748 }
749
750 /**
751 * msgdma_dev_remove() - Device remove function
752 * @mdev: Pointer to the Altera mSGDMA device structure
753 */
msgdma_dev_remove(struct msgdma_device * mdev)754 static void msgdma_dev_remove(struct msgdma_device *mdev)
755 {
756 if (!mdev)
757 return;
758
759 devm_free_irq(mdev->dev, mdev->irq, mdev);
760 tasklet_kill(&mdev->irq_tasklet);
761 list_del(&mdev->dmachan.device_node);
762 }
763
request_and_map(struct platform_device * pdev,const char * name,struct resource ** res,void __iomem ** ptr,bool optional)764 static int request_and_map(struct platform_device *pdev, const char *name,
765 struct resource **res, void __iomem **ptr,
766 bool optional)
767 {
768 struct resource *region;
769 struct device *device = &pdev->dev;
770
771 *res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
772 if (*res == NULL) {
773 if (optional) {
774 *ptr = NULL;
775 dev_info(device, "optional resource %s not defined\n",
776 name);
777 return 0;
778 }
779 dev_err(device, "mandatory resource %s not defined\n", name);
780 return -ENODEV;
781 }
782
783 region = devm_request_mem_region(device, (*res)->start,
784 resource_size(*res), dev_name(device));
785 if (region == NULL) {
786 dev_err(device, "unable to request %s\n", name);
787 return -EBUSY;
788 }
789
790 *ptr = devm_ioremap(device, region->start,
791 resource_size(region));
792 if (*ptr == NULL) {
793 dev_err(device, "ioremap of %s failed!", name);
794 return -ENOMEM;
795 }
796
797 return 0;
798 }
799
800 /**
801 * msgdma_probe - Driver probe function
802 * @pdev: Pointer to the platform_device structure
803 *
804 * Return: '0' on success and failure value on error
805 */
msgdma_probe(struct platform_device * pdev)806 static int msgdma_probe(struct platform_device *pdev)
807 {
808 struct msgdma_device *mdev;
809 struct dma_device *dma_dev;
810 struct resource *dma_res;
811 int ret;
812
813 mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_NOWAIT);
814 if (!mdev)
815 return -ENOMEM;
816
817 mdev->dev = &pdev->dev;
818
819 /* Map CSR space */
820 ret = request_and_map(pdev, "csr", &dma_res, &mdev->csr, false);
821 if (ret)
822 return ret;
823
824 /* Map (extended) descriptor space */
825 ret = request_and_map(pdev, "desc", &dma_res, &mdev->desc, false);
826 if (ret)
827 return ret;
828
829 /* Map response space */
830 ret = request_and_map(pdev, "resp", &dma_res, &mdev->resp, true);
831 if (ret)
832 return ret;
833
834 platform_set_drvdata(pdev, mdev);
835
836 /* Get interrupt nr from platform data */
837 mdev->irq = platform_get_irq(pdev, 0);
838 if (mdev->irq < 0)
839 return -ENXIO;
840
841 ret = devm_request_irq(&pdev->dev, mdev->irq, msgdma_irq_handler,
842 0, dev_name(&pdev->dev), mdev);
843 if (ret)
844 return ret;
845
846 tasklet_setup(&mdev->irq_tasklet, msgdma_tasklet);
847
848 dma_cookie_init(&mdev->dmachan);
849
850 spin_lock_init(&mdev->lock);
851
852 INIT_LIST_HEAD(&mdev->active_list);
853 INIT_LIST_HEAD(&mdev->pending_list);
854 INIT_LIST_HEAD(&mdev->done_list);
855 INIT_LIST_HEAD(&mdev->free_list);
856
857 dma_dev = &mdev->dmadev;
858
859 /* Set DMA capabilities */
860 dma_cap_zero(dma_dev->cap_mask);
861 dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
862 dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
863
864 dma_dev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
865 dma_dev->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
866 dma_dev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM) |
867 BIT(DMA_MEM_TO_MEM);
868 dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR;
869
870 /* Init DMA link list */
871 INIT_LIST_HEAD(&dma_dev->channels);
872
873 /* Set base routines */
874 dma_dev->device_tx_status = dma_cookie_status;
875 dma_dev->device_issue_pending = msgdma_issue_pending;
876 dma_dev->dev = &pdev->dev;
877
878 dma_dev->copy_align = DMAENGINE_ALIGN_4_BYTES;
879 dma_dev->device_prep_dma_memcpy = msgdma_prep_memcpy;
880 dma_dev->device_prep_slave_sg = msgdma_prep_slave_sg;
881 dma_dev->device_config = msgdma_dma_config;
882
883 dma_dev->device_alloc_chan_resources = msgdma_alloc_chan_resources;
884 dma_dev->device_free_chan_resources = msgdma_free_chan_resources;
885
886 mdev->dmachan.device = dma_dev;
887 list_add_tail(&mdev->dmachan.device_node, &dma_dev->channels);
888
889 /* Set DMA mask to 64 bits */
890 ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
891 if (ret) {
892 dev_warn(&pdev->dev, "unable to set coherent mask to 64");
893 goto fail;
894 }
895
896 msgdma_reset(mdev);
897
898 ret = dma_async_device_register(dma_dev);
899 if (ret)
900 goto fail;
901
902 ret = of_dma_controller_register(pdev->dev.of_node,
903 of_dma_xlate_by_chan_id, dma_dev);
904 if (ret == -EINVAL)
905 dev_warn(&pdev->dev, "device was not probed from DT");
906 else if (ret && ret != -ENODEV)
907 goto fail;
908
909 dev_notice(&pdev->dev, "Altera mSGDMA driver probe success\n");
910
911 return 0;
912
913 fail:
914 msgdma_dev_remove(mdev);
915
916 return ret;
917 }
918
919 /**
920 * msgdma_remove() - Driver remove function
921 * @pdev: Pointer to the platform_device structure
922 *
923 * Return: Always '0'
924 */
msgdma_remove(struct platform_device * pdev)925 static int msgdma_remove(struct platform_device *pdev)
926 {
927 struct msgdma_device *mdev = platform_get_drvdata(pdev);
928
929 if (pdev->dev.of_node)
930 of_dma_controller_free(pdev->dev.of_node);
931 dma_async_device_unregister(&mdev->dmadev);
932 msgdma_dev_remove(mdev);
933
934 dev_notice(&pdev->dev, "Altera mSGDMA driver removed\n");
935
936 return 0;
937 }
938
939 #ifdef CONFIG_OF
940 static const struct of_device_id msgdma_match[] = {
941 { .compatible = "altr,socfpga-msgdma", },
942 { }
943 };
944
945 MODULE_DEVICE_TABLE(of, msgdma_match);
946 #endif
947
948 static struct platform_driver msgdma_driver = {
949 .driver = {
950 .name = "altera-msgdma",
951 .of_match_table = of_match_ptr(msgdma_match),
952 },
953 .probe = msgdma_probe,
954 .remove = msgdma_remove,
955 };
956
957 module_platform_driver(msgdma_driver);
958
959 MODULE_ALIAS("platform:altera-msgdma");
960 MODULE_DESCRIPTION("Altera mSGDMA driver");
961 MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
962 MODULE_LICENSE("GPL");
963