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a85c6f1b SR |
1 | /* |
2 | * DMA driver for Altera mSGDMA IP core | |
3 | * | |
4 | * Copyright (C) 2017 Stefan Roese <sr@denx.de> | |
5 | * | |
6 | * Based on drivers/dma/xilinx/zynqmp_dma.c, which is: | |
7 | * Copyright (C) 2016 Xilinx, Inc. All rights reserved. | |
8 | * | |
9 | * This program is free software: you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation, either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | */ | |
14 | ||
15 | #include <linux/bitops.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/dma-mapping.h> | |
18 | #include <linux/dmapool.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/interrupt.h> | |
21 | #include <linux/io.h> | |
22 | #include <linux/iopoll.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/slab.h> | |
26 | ||
27 | #include "dmaengine.h" | |
28 | ||
29 | #define MSGDMA_MAX_TRANS_LEN U32_MAX | |
30 | #define MSGDMA_DESC_NUM 1024 | |
31 | ||
32 | /** | |
33 | * struct msgdma_extended_desc - implements an extended descriptor | |
34 | * @read_addr_lo: data buffer source address low bits | |
35 | * @write_addr_lo: data buffer destination address low bits | |
36 | * @len: the number of bytes to transfer per descriptor | |
37 | * @burst_seq_num: bit 31:24 write burst | |
38 | * bit 23:16 read burst | |
39 | * bit 15:00 sequence number | |
40 | * @stride: bit 31:16 write stride | |
41 | * bit 15:00 read stride | |
42 | * @read_addr_hi: data buffer source address high bits | |
43 | * @write_addr_hi: data buffer destination address high bits | |
44 | * @control: characteristics of the transfer | |
45 | */ | |
46 | struct msgdma_extended_desc { | |
47 | u32 read_addr_lo; | |
48 | u32 write_addr_lo; | |
49 | u32 len; | |
50 | u32 burst_seq_num; | |
51 | u32 stride; | |
52 | u32 read_addr_hi; | |
53 | u32 write_addr_hi; | |
54 | u32 control; | |
55 | }; | |
56 | ||
57 | /* mSGDMA descriptor control field bit definitions */ | |
58 | #define MSGDMA_DESC_CTL_SET_CH(x) ((x) & 0xff) | |
59 | #define MSGDMA_DESC_CTL_GEN_SOP BIT(8) | |
60 | #define MSGDMA_DESC_CTL_GEN_EOP BIT(9) | |
61 | #define MSGDMA_DESC_CTL_PARK_READS BIT(10) | |
62 | #define MSGDMA_DESC_CTL_PARK_WRITES BIT(11) | |
63 | #define MSGDMA_DESC_CTL_END_ON_EOP BIT(12) | |
64 | #define MSGDMA_DESC_CTL_END_ON_LEN BIT(13) | |
65 | #define MSGDMA_DESC_CTL_TR_COMP_IRQ BIT(14) | |
66 | #define MSGDMA_DESC_CTL_EARLY_IRQ BIT(15) | |
67 | #define MSGDMA_DESC_CTL_TR_ERR_IRQ GENMASK(23, 16) | |
68 | #define MSGDMA_DESC_CTL_EARLY_DONE BIT(24) | |
69 | ||
70 | /* | |
71 | * Writing "1" the "go" bit commits the entire descriptor into the | |
72 | * descriptor FIFO(s) | |
73 | */ | |
74 | #define MSGDMA_DESC_CTL_GO BIT(31) | |
75 | ||
76 | /* Tx buffer control flags */ | |
77 | #define MSGDMA_DESC_CTL_TX_FIRST (MSGDMA_DESC_CTL_GEN_SOP | \ | |
78 | MSGDMA_DESC_CTL_TR_ERR_IRQ | \ | |
79 | MSGDMA_DESC_CTL_GO) | |
80 | ||
81 | #define MSGDMA_DESC_CTL_TX_MIDDLE (MSGDMA_DESC_CTL_TR_ERR_IRQ | \ | |
82 | MSGDMA_DESC_CTL_GO) | |
83 | ||
84 | #define MSGDMA_DESC_CTL_TX_LAST (MSGDMA_DESC_CTL_GEN_EOP | \ | |
85 | MSGDMA_DESC_CTL_TR_COMP_IRQ | \ | |
86 | MSGDMA_DESC_CTL_TR_ERR_IRQ | \ | |
87 | MSGDMA_DESC_CTL_GO) | |
88 | ||
89 | #define MSGDMA_DESC_CTL_TX_SINGLE (MSGDMA_DESC_CTL_GEN_SOP | \ | |
90 | MSGDMA_DESC_CTL_GEN_EOP | \ | |
91 | MSGDMA_DESC_CTL_TR_COMP_IRQ | \ | |
92 | MSGDMA_DESC_CTL_TR_ERR_IRQ | \ | |
93 | MSGDMA_DESC_CTL_GO) | |
94 | ||
95 | #define MSGDMA_DESC_CTL_RX_SINGLE (MSGDMA_DESC_CTL_END_ON_EOP | \ | |
96 | MSGDMA_DESC_CTL_END_ON_LEN | \ | |
97 | MSGDMA_DESC_CTL_TR_COMP_IRQ | \ | |
98 | MSGDMA_DESC_CTL_EARLY_IRQ | \ | |
99 | MSGDMA_DESC_CTL_TR_ERR_IRQ | \ | |
100 | MSGDMA_DESC_CTL_GO) | |
101 | ||
102 | /* mSGDMA extended descriptor stride definitions */ | |
103 | #define MSGDMA_DESC_STRIDE_RD 0x00000001 | |
104 | #define MSGDMA_DESC_STRIDE_WR 0x00010000 | |
105 | #define MSGDMA_DESC_STRIDE_RW 0x00010001 | |
106 | ||
107 | /** | |
108 | * struct msgdma_csr - mSGDMA dispatcher control and status register map | |
109 | * @status: Read/Clear | |
110 | * @control: Read/Write | |
111 | * @rw_fill_level: bit 31:16 - write fill level | |
112 | * bit 15:00 - read fill level | |
113 | * @resp_fill_level: bit 15:00 - response FIFO fill level | |
114 | * @rw_seq_num: bit 31:16 - write sequence number | |
115 | * bit 15:00 - read sequence number | |
116 | * @pad: reserved | |
117 | */ | |
118 | struct msgdma_csr { | |
119 | u32 status; | |
120 | u32 control; | |
121 | u32 rw_fill_level; | |
122 | u32 resp_fill_level; | |
123 | u32 rw_seq_num; | |
124 | u32 pad[3]; | |
125 | }; | |
126 | ||
127 | /* mSGDMA CSR status register bit definitions */ | |
128 | #define MSGDMA_CSR_STAT_BUSY BIT(0) | |
129 | #define MSGDMA_CSR_STAT_DESC_BUF_EMPTY BIT(1) | |
130 | #define MSGDMA_CSR_STAT_DESC_BUF_FULL BIT(2) | |
131 | #define MSGDMA_CSR_STAT_RESP_BUF_EMPTY BIT(3) | |
132 | #define MSGDMA_CSR_STAT_RESP_BUF_FULL BIT(4) | |
133 | #define MSGDMA_CSR_STAT_STOPPED BIT(5) | |
134 | #define MSGDMA_CSR_STAT_RESETTING BIT(6) | |
135 | #define MSGDMA_CSR_STAT_STOPPED_ON_ERR BIT(7) | |
136 | #define MSGDMA_CSR_STAT_STOPPED_ON_EARLY BIT(8) | |
137 | #define MSGDMA_CSR_STAT_IRQ BIT(9) | |
138 | #define MSGDMA_CSR_STAT_MASK GENMASK(9, 0) | |
139 | #define MSGDMA_CSR_STAT_MASK_WITHOUT_IRQ GENMASK(8, 0) | |
140 | ||
141 | #define DESC_EMPTY (MSGDMA_CSR_STAT_DESC_BUF_EMPTY | \ | |
142 | MSGDMA_CSR_STAT_RESP_BUF_EMPTY) | |
143 | ||
144 | /* mSGDMA CSR control register bit definitions */ | |
145 | #define MSGDMA_CSR_CTL_STOP BIT(0) | |
146 | #define MSGDMA_CSR_CTL_RESET BIT(1) | |
147 | #define MSGDMA_CSR_CTL_STOP_ON_ERR BIT(2) | |
148 | #define MSGDMA_CSR_CTL_STOP_ON_EARLY BIT(3) | |
149 | #define MSGDMA_CSR_CTL_GLOBAL_INTR BIT(4) | |
150 | #define MSGDMA_CSR_CTL_STOP_DESCS BIT(5) | |
151 | ||
152 | /* mSGDMA CSR fill level bits */ | |
153 | #define MSGDMA_CSR_WR_FILL_LEVEL_GET(v) (((v) & 0xffff0000) >> 16) | |
154 | #define MSGDMA_CSR_RD_FILL_LEVEL_GET(v) ((v) & 0x0000ffff) | |
155 | #define MSGDMA_CSR_RESP_FILL_LEVEL_GET(v) ((v) & 0x0000ffff) | |
156 | ||
157 | #define MSGDMA_CSR_SEQ_NUM_GET(v) (((v) & 0xffff0000) >> 16) | |
158 | ||
159 | /* mSGDMA response register map */ | |
160 | struct msgdma_response { | |
161 | u32 bytes_transferred; | |
162 | u32 status; | |
163 | }; | |
164 | ||
165 | /* mSGDMA response register bit definitions */ | |
166 | #define MSGDMA_RESP_EARLY_TERM BIT(8) | |
167 | #define MSGDMA_RESP_ERR_MASK 0xff | |
168 | ||
169 | /** | |
170 | * struct msgdma_sw_desc - implements a sw descriptor | |
171 | * @async_tx: support for the async_tx api | |
172 | * @hw_desc: assosiated HW descriptor | |
173 | * @free_list: node of the free SW descriprots list | |
174 | */ | |
175 | struct msgdma_sw_desc { | |
176 | struct dma_async_tx_descriptor async_tx; | |
177 | struct msgdma_extended_desc hw_desc; | |
178 | struct list_head node; | |
179 | struct list_head tx_list; | |
180 | }; | |
181 | ||
182 | /** | |
183 | * struct msgdma_device - DMA device structure | |
184 | */ | |
185 | struct msgdma_device { | |
186 | spinlock_t lock; | |
187 | struct device *dev; | |
188 | struct tasklet_struct irq_tasklet; | |
189 | struct list_head pending_list; | |
190 | struct list_head free_list; | |
191 | struct list_head active_list; | |
192 | struct list_head done_list; | |
193 | u32 desc_free_cnt; | |
194 | bool idle; | |
195 | ||
196 | struct dma_device dmadev; | |
197 | struct dma_chan dmachan; | |
198 | dma_addr_t hw_desq; | |
199 | struct msgdma_sw_desc *sw_desq; | |
200 | unsigned int npendings; | |
201 | ||
202 | struct dma_slave_config slave_cfg; | |
203 | ||
204 | int irq; | |
205 | ||
206 | /* mSGDMA controller */ | |
207 | struct msgdma_csr *csr; | |
208 | ||
209 | /* mSGDMA descriptors */ | |
210 | struct msgdma_extended_desc *desc; | |
211 | ||
212 | /* mSGDMA response */ | |
213 | struct msgdma_response *resp; | |
214 | }; | |
215 | ||
216 | #define to_mdev(chan) container_of(chan, struct msgdma_device, dmachan) | |
217 | #define tx_to_desc(tx) container_of(tx, struct msgdma_sw_desc, async_tx) | |
218 | ||
219 | /** | |
220 | * msgdma_get_descriptor - Get the sw descriptor from the pool | |
221 | * @mdev: Pointer to the Altera mSGDMA device structure | |
222 | * | |
223 | * Return: The sw descriptor | |
224 | */ | |
225 | static struct msgdma_sw_desc *msgdma_get_descriptor(struct msgdma_device *mdev) | |
226 | { | |
227 | struct msgdma_sw_desc *desc; | |
228 | ||
229 | spin_lock_bh(&mdev->lock); | |
230 | desc = list_first_entry(&mdev->free_list, struct msgdma_sw_desc, node); | |
231 | list_del(&desc->node); | |
232 | spin_unlock_bh(&mdev->lock); | |
233 | ||
234 | INIT_LIST_HEAD(&desc->tx_list); | |
235 | ||
236 | return desc; | |
237 | } | |
238 | ||
239 | /** | |
240 | * msgdma_free_descriptor - Issue pending transactions | |
241 | * @mdev: Pointer to the Altera mSGDMA device structure | |
242 | * @desc: Transaction descriptor pointer | |
243 | */ | |
244 | static void msgdma_free_descriptor(struct msgdma_device *mdev, | |
245 | struct msgdma_sw_desc *desc) | |
246 | { | |
247 | struct msgdma_sw_desc *child, *next; | |
248 | ||
249 | mdev->desc_free_cnt++; | |
250 | list_add_tail(&desc->node, &mdev->free_list); | |
251 | list_for_each_entry_safe(child, next, &desc->tx_list, node) { | |
252 | mdev->desc_free_cnt++; | |
253 | list_move_tail(&child->node, &mdev->free_list); | |
254 | } | |
255 | } | |
256 | ||
257 | /** | |
258 | * msgdma_free_desc_list - Free descriptors list | |
259 | * @mdev: Pointer to the Altera mSGDMA device structure | |
260 | * @list: List to parse and delete the descriptor | |
261 | */ | |
262 | static void msgdma_free_desc_list(struct msgdma_device *mdev, | |
263 | struct list_head *list) | |
264 | { | |
265 | struct msgdma_sw_desc *desc, *next; | |
266 | ||
267 | list_for_each_entry_safe(desc, next, list, node) | |
268 | msgdma_free_descriptor(mdev, desc); | |
269 | } | |
270 | ||
271 | /** | |
272 | * msgdma_desc_config - Configure the descriptor | |
273 | * @desc: Hw descriptor pointer | |
274 | * @dst: Destination buffer address | |
275 | * @src: Source buffer address | |
276 | * @len: Transfer length | |
277 | */ | |
278 | static void msgdma_desc_config(struct msgdma_extended_desc *desc, | |
279 | dma_addr_t dst, dma_addr_t src, size_t len, | |
280 | u32 stride) | |
281 | { | |
282 | /* Set lower 32bits of src & dst addresses in the descriptor */ | |
283 | desc->read_addr_lo = lower_32_bits(src); | |
284 | desc->write_addr_lo = lower_32_bits(dst); | |
285 | ||
286 | /* Set upper 32bits of src & dst addresses in the descriptor */ | |
287 | desc->read_addr_hi = upper_32_bits(src); | |
288 | desc->write_addr_hi = upper_32_bits(dst); | |
289 | ||
290 | desc->len = len; | |
291 | desc->stride = stride; | |
292 | desc->burst_seq_num = 0; /* 0 will result in max burst length */ | |
293 | ||
294 | /* | |
295 | * Don't set interrupt on xfer end yet, this will be done later | |
296 | * for the "last" descriptor | |
297 | */ | |
298 | desc->control = MSGDMA_DESC_CTL_TR_ERR_IRQ | MSGDMA_DESC_CTL_GO | | |
299 | MSGDMA_DESC_CTL_END_ON_LEN; | |
300 | } | |
301 | ||
302 | /** | |
303 | * msgdma_desc_config_eod - Mark the descriptor as end descriptor | |
304 | * @desc: Hw descriptor pointer | |
305 | */ | |
306 | static void msgdma_desc_config_eod(struct msgdma_extended_desc *desc) | |
307 | { | |
308 | desc->control |= MSGDMA_DESC_CTL_TR_COMP_IRQ; | |
309 | } | |
310 | ||
311 | /** | |
312 | * msgdma_tx_submit - Submit DMA transaction | |
313 | * @tx: Async transaction descriptor pointer | |
314 | * | |
315 | * Return: cookie value | |
316 | */ | |
317 | static dma_cookie_t msgdma_tx_submit(struct dma_async_tx_descriptor *tx) | |
318 | { | |
319 | struct msgdma_device *mdev = to_mdev(tx->chan); | |
320 | struct msgdma_sw_desc *new; | |
321 | dma_cookie_t cookie; | |
322 | ||
323 | new = tx_to_desc(tx); | |
324 | spin_lock_bh(&mdev->lock); | |
325 | cookie = dma_cookie_assign(tx); | |
326 | ||
327 | list_add_tail(&new->node, &mdev->pending_list); | |
328 | spin_unlock_bh(&mdev->lock); | |
329 | ||
330 | return cookie; | |
331 | } | |
332 | ||
333 | /** | |
334 | * msgdma_prep_memcpy - prepare descriptors for memcpy transaction | |
335 | * @dchan: DMA channel | |
336 | * @dma_dst: Destination buffer address | |
337 | * @dma_src: Source buffer address | |
338 | * @len: Transfer length | |
339 | * @flags: transfer ack flags | |
340 | * | |
341 | * Return: Async transaction descriptor on success and NULL on failure | |
342 | */ | |
343 | static struct dma_async_tx_descriptor * | |
344 | msgdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst, | |
345 | dma_addr_t dma_src, size_t len, ulong flags) | |
346 | { | |
347 | struct msgdma_device *mdev = to_mdev(dchan); | |
348 | struct msgdma_sw_desc *new, *first = NULL; | |
349 | struct msgdma_extended_desc *desc; | |
350 | size_t copy; | |
351 | u32 desc_cnt; | |
352 | ||
353 | desc_cnt = DIV_ROUND_UP(len, MSGDMA_MAX_TRANS_LEN); | |
354 | ||
355 | spin_lock_bh(&mdev->lock); | |
356 | if (desc_cnt > mdev->desc_free_cnt) { | |
357 | spin_unlock_bh(&mdev->lock); | |
358 | dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev); | |
359 | return NULL; | |
360 | } | |
361 | mdev->desc_free_cnt -= desc_cnt; | |
362 | spin_unlock_bh(&mdev->lock); | |
363 | ||
364 | do { | |
365 | /* Allocate and populate the descriptor */ | |
366 | new = msgdma_get_descriptor(mdev); | |
367 | ||
368 | copy = min_t(size_t, len, MSGDMA_MAX_TRANS_LEN); | |
369 | desc = &new->hw_desc; | |
370 | msgdma_desc_config(desc, dma_dst, dma_src, copy, | |
371 | MSGDMA_DESC_STRIDE_RW); | |
372 | len -= copy; | |
373 | dma_src += copy; | |
374 | dma_dst += copy; | |
375 | if (!first) | |
376 | first = new; | |
377 | else | |
378 | list_add_tail(&new->node, &first->tx_list); | |
379 | } while (len); | |
380 | ||
381 | msgdma_desc_config_eod(desc); | |
382 | async_tx_ack(&first->async_tx); | |
383 | first->async_tx.flags = flags; | |
384 | ||
385 | return &first->async_tx; | |
386 | } | |
387 | ||
a85c6f1b SR |
388 | /** |
389 | * msgdma_prep_slave_sg - prepare descriptors for a slave sg transaction | |
390 | * | |
391 | * @dchan: DMA channel | |
392 | * @sgl: Destination scatter list | |
393 | * @sg_len: Number of entries in destination scatter list | |
394 | * @dir: DMA transfer direction | |
395 | * @flags: transfer ack flags | |
396 | * @context: transfer context (unused) | |
397 | */ | |
398 | static struct dma_async_tx_descriptor * | |
399 | msgdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl, | |
400 | unsigned int sg_len, enum dma_transfer_direction dir, | |
401 | unsigned long flags, void *context) | |
402 | ||
403 | { | |
404 | struct msgdma_device *mdev = to_mdev(dchan); | |
405 | struct dma_slave_config *cfg = &mdev->slave_cfg; | |
406 | struct msgdma_sw_desc *new, *first = NULL; | |
407 | void *desc = NULL; | |
408 | size_t len, avail; | |
409 | dma_addr_t dma_dst, dma_src; | |
410 | u32 desc_cnt = 0, i; | |
411 | struct scatterlist *sg; | |
412 | u32 stride; | |
413 | ||
414 | for_each_sg(sgl, sg, sg_len, i) | |
415 | desc_cnt += DIV_ROUND_UP(sg_dma_len(sg), MSGDMA_MAX_TRANS_LEN); | |
416 | ||
417 | spin_lock_bh(&mdev->lock); | |
418 | if (desc_cnt > mdev->desc_free_cnt) { | |
419 | spin_unlock_bh(&mdev->lock); | |
420 | dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev); | |
421 | return NULL; | |
422 | } | |
423 | mdev->desc_free_cnt -= desc_cnt; | |
424 | spin_unlock_bh(&mdev->lock); | |
425 | ||
426 | avail = sg_dma_len(sgl); | |
427 | ||
428 | /* Run until we are out of scatterlist entries */ | |
429 | while (true) { | |
430 | /* Allocate and populate the descriptor */ | |
431 | new = msgdma_get_descriptor(mdev); | |
432 | ||
433 | desc = &new->hw_desc; | |
434 | len = min_t(size_t, avail, MSGDMA_MAX_TRANS_LEN); | |
435 | ||
436 | if (dir == DMA_MEM_TO_DEV) { | |
437 | dma_src = sg_dma_address(sgl) + sg_dma_len(sgl) - avail; | |
438 | dma_dst = cfg->dst_addr; | |
439 | stride = MSGDMA_DESC_STRIDE_RD; | |
440 | } else { | |
441 | dma_src = cfg->src_addr; | |
442 | dma_dst = sg_dma_address(sgl) + sg_dma_len(sgl) - avail; | |
443 | stride = MSGDMA_DESC_STRIDE_WR; | |
444 | } | |
445 | msgdma_desc_config(desc, dma_dst, dma_src, len, stride); | |
446 | avail -= len; | |
447 | ||
448 | if (!first) | |
449 | first = new; | |
450 | else | |
451 | list_add_tail(&new->node, &first->tx_list); | |
452 | ||
453 | /* Fetch the next scatterlist entry */ | |
454 | if (avail == 0) { | |
455 | if (sg_len == 0) | |
456 | break; | |
457 | sgl = sg_next(sgl); | |
458 | if (sgl == NULL) | |
459 | break; | |
460 | sg_len--; | |
461 | avail = sg_dma_len(sgl); | |
462 | } | |
463 | } | |
464 | ||
465 | msgdma_desc_config_eod(desc); | |
466 | first->async_tx.flags = flags; | |
467 | ||
468 | return &first->async_tx; | |
469 | } | |
470 | ||
471 | static int msgdma_dma_config(struct dma_chan *dchan, | |
472 | struct dma_slave_config *config) | |
473 | { | |
474 | struct msgdma_device *mdev = to_mdev(dchan); | |
475 | ||
476 | memcpy(&mdev->slave_cfg, config, sizeof(*config)); | |
477 | ||
478 | return 0; | |
479 | } | |
480 | ||
481 | static void msgdma_reset(struct msgdma_device *mdev) | |
482 | { | |
483 | u32 val; | |
484 | int ret; | |
485 | ||
486 | /* Reset mSGDMA */ | |
487 | iowrite32(MSGDMA_CSR_STAT_MASK, &mdev->csr->status); | |
488 | iowrite32(MSGDMA_CSR_CTL_RESET, &mdev->csr->control); | |
489 | ||
490 | ret = readl_poll_timeout(&mdev->csr->status, val, | |
491 | (val & MSGDMA_CSR_STAT_RESETTING) == 0, | |
492 | 1, 10000); | |
493 | if (ret) | |
494 | dev_err(mdev->dev, "DMA channel did not reset\n"); | |
495 | ||
496 | /* Clear all status bits */ | |
497 | iowrite32(MSGDMA_CSR_STAT_MASK, &mdev->csr->status); | |
498 | ||
499 | /* Enable the DMA controller including interrupts */ | |
500 | iowrite32(MSGDMA_CSR_CTL_STOP_ON_ERR | MSGDMA_CSR_CTL_STOP_ON_EARLY | | |
501 | MSGDMA_CSR_CTL_GLOBAL_INTR, &mdev->csr->control); | |
502 | ||
503 | mdev->idle = true; | |
504 | }; | |
505 | ||
506 | static void msgdma_copy_one(struct msgdma_device *mdev, | |
507 | struct msgdma_sw_desc *desc) | |
508 | { | |
509 | struct msgdma_extended_desc *hw_desc = mdev->desc; | |
510 | ||
511 | /* | |
512 | * Check if the DESC FIFO it not full. If its full, we need to wait | |
513 | * for at least one entry to become free again | |
514 | */ | |
515 | while (ioread32(&mdev->csr->status) & MSGDMA_CSR_STAT_DESC_BUF_FULL) | |
516 | mdelay(1); | |
517 | ||
518 | /* | |
519 | * The descriptor needs to get copied into the descriptor FIFO | |
520 | * of the DMA controller. The descriptor will get flushed to the | |
521 | * FIFO, once the last word (control word) is written. Since we | |
522 | * are not 100% sure that memcpy() writes all word in the "correct" | |
523 | * oder (address from low to high) on all architectures, we make | |
524 | * sure this control word is written last by single coding it and | |
525 | * adding some write-barriers here. | |
526 | */ | |
527 | memcpy(hw_desc, &desc->hw_desc, sizeof(desc->hw_desc) - sizeof(u32)); | |
528 | ||
529 | /* Write control word last to flush this descriptor into the FIFO */ | |
530 | mdev->idle = false; | |
531 | wmb(); | |
532 | iowrite32(desc->hw_desc.control, &hw_desc->control); | |
533 | wmb(); | |
534 | } | |
535 | ||
536 | /** | |
537 | * msgdma_copy_desc_to_fifo - copy descriptor(s) into controller FIFO | |
538 | * @mdev: Pointer to the Altera mSGDMA device structure | |
539 | * @desc: Transaction descriptor pointer | |
540 | */ | |
541 | static void msgdma_copy_desc_to_fifo(struct msgdma_device *mdev, | |
542 | struct msgdma_sw_desc *desc) | |
543 | { | |
544 | struct msgdma_sw_desc *sdesc, *next; | |
545 | ||
546 | msgdma_copy_one(mdev, desc); | |
547 | ||
548 | list_for_each_entry_safe(sdesc, next, &desc->tx_list, node) | |
549 | msgdma_copy_one(mdev, sdesc); | |
550 | } | |
551 | ||
552 | /** | |
553 | * msgdma_start_transfer - Initiate the new transfer | |
554 | * @mdev: Pointer to the Altera mSGDMA device structure | |
555 | */ | |
556 | static void msgdma_start_transfer(struct msgdma_device *mdev) | |
557 | { | |
558 | struct msgdma_sw_desc *desc; | |
559 | ||
560 | if (!mdev->idle) | |
561 | return; | |
562 | ||
563 | desc = list_first_entry_or_null(&mdev->pending_list, | |
564 | struct msgdma_sw_desc, node); | |
565 | if (!desc) | |
566 | return; | |
567 | ||
568 | list_splice_tail_init(&mdev->pending_list, &mdev->active_list); | |
569 | msgdma_copy_desc_to_fifo(mdev, desc); | |
570 | } | |
571 | ||
572 | /** | |
573 | * msgdma_issue_pending - Issue pending transactions | |
574 | * @chan: DMA channel pointer | |
575 | */ | |
576 | static void msgdma_issue_pending(struct dma_chan *chan) | |
577 | { | |
578 | struct msgdma_device *mdev = to_mdev(chan); | |
579 | ||
580 | spin_lock_bh(&mdev->lock); | |
581 | msgdma_start_transfer(mdev); | |
582 | spin_unlock_bh(&mdev->lock); | |
583 | } | |
584 | ||
585 | /** | |
586 | * msgdma_chan_desc_cleanup - Cleanup the completed descriptors | |
587 | * @mdev: Pointer to the Altera mSGDMA device structure | |
588 | */ | |
589 | static void msgdma_chan_desc_cleanup(struct msgdma_device *mdev) | |
590 | { | |
591 | struct msgdma_sw_desc *desc, *next; | |
592 | ||
593 | list_for_each_entry_safe(desc, next, &mdev->done_list, node) { | |
594 | dma_async_tx_callback callback; | |
595 | void *callback_param; | |
596 | ||
597 | list_del(&desc->node); | |
598 | ||
599 | callback = desc->async_tx.callback; | |
600 | callback_param = desc->async_tx.callback_param; | |
601 | if (callback) { | |
602 | spin_unlock(&mdev->lock); | |
603 | callback(callback_param); | |
604 | spin_lock(&mdev->lock); | |
605 | } | |
606 | ||
607 | /* Run any dependencies, then free the descriptor */ | |
608 | msgdma_free_descriptor(mdev, desc); | |
609 | } | |
610 | } | |
611 | ||
612 | /** | |
613 | * msgdma_complete_descriptor - Mark the active descriptor as complete | |
614 | * @mdev: Pointer to the Altera mSGDMA device structure | |
615 | */ | |
616 | static void msgdma_complete_descriptor(struct msgdma_device *mdev) | |
617 | { | |
618 | struct msgdma_sw_desc *desc; | |
619 | ||
620 | desc = list_first_entry_or_null(&mdev->active_list, | |
621 | struct msgdma_sw_desc, node); | |
622 | if (!desc) | |
623 | return; | |
624 | list_del(&desc->node); | |
625 | dma_cookie_complete(&desc->async_tx); | |
626 | list_add_tail(&desc->node, &mdev->done_list); | |
627 | } | |
628 | ||
629 | /** | |
630 | * msgdma_free_descriptors - Free channel descriptors | |
631 | * @mdev: Pointer to the Altera mSGDMA device structure | |
632 | */ | |
633 | static void msgdma_free_descriptors(struct msgdma_device *mdev) | |
634 | { | |
635 | msgdma_free_desc_list(mdev, &mdev->active_list); | |
636 | msgdma_free_desc_list(mdev, &mdev->pending_list); | |
637 | msgdma_free_desc_list(mdev, &mdev->done_list); | |
638 | } | |
639 | ||
640 | /** | |
641 | * msgdma_free_chan_resources - Free channel resources | |
642 | * @dchan: DMA channel pointer | |
643 | */ | |
644 | static void msgdma_free_chan_resources(struct dma_chan *dchan) | |
645 | { | |
646 | struct msgdma_device *mdev = to_mdev(dchan); | |
647 | ||
648 | spin_lock_bh(&mdev->lock); | |
649 | msgdma_free_descriptors(mdev); | |
650 | spin_unlock_bh(&mdev->lock); | |
651 | kfree(mdev->sw_desq); | |
652 | } | |
653 | ||
654 | /** | |
655 | * msgdma_alloc_chan_resources - Allocate channel resources | |
656 | * @dchan: DMA channel | |
657 | * | |
658 | * Return: Number of descriptors on success and failure value on error | |
659 | */ | |
660 | static int msgdma_alloc_chan_resources(struct dma_chan *dchan) | |
661 | { | |
662 | struct msgdma_device *mdev = to_mdev(dchan); | |
663 | struct msgdma_sw_desc *desc; | |
664 | int i; | |
665 | ||
666 | mdev->sw_desq = kcalloc(MSGDMA_DESC_NUM, sizeof(*desc), GFP_NOWAIT); | |
667 | if (!mdev->sw_desq) | |
668 | return -ENOMEM; | |
669 | ||
670 | mdev->idle = true; | |
671 | mdev->desc_free_cnt = MSGDMA_DESC_NUM; | |
672 | ||
673 | INIT_LIST_HEAD(&mdev->free_list); | |
674 | ||
675 | for (i = 0; i < MSGDMA_DESC_NUM; i++) { | |
676 | desc = mdev->sw_desq + i; | |
677 | dma_async_tx_descriptor_init(&desc->async_tx, &mdev->dmachan); | |
678 | desc->async_tx.tx_submit = msgdma_tx_submit; | |
679 | list_add_tail(&desc->node, &mdev->free_list); | |
680 | } | |
681 | ||
682 | return MSGDMA_DESC_NUM; | |
683 | } | |
684 | ||
685 | /** | |
686 | * msgdma_tasklet - Schedule completion tasklet | |
687 | * @data: Pointer to the Altera sSGDMA channel structure | |
688 | */ | |
689 | static void msgdma_tasklet(unsigned long data) | |
690 | { | |
691 | struct msgdma_device *mdev = (struct msgdma_device *)data; | |
692 | u32 count; | |
693 | u32 size; | |
694 | u32 status; | |
695 | ||
696 | spin_lock(&mdev->lock); | |
697 | ||
698 | /* Read number of responses that are available */ | |
699 | count = ioread32(&mdev->csr->resp_fill_level); | |
700 | dev_dbg(mdev->dev, "%s (%d): response count=%d\n", | |
701 | __func__, __LINE__, count); | |
702 | ||
703 | while (count--) { | |
704 | /* | |
705 | * Read both longwords to purge this response from the FIFO | |
706 | * On Avalon-MM implementations, size and status do not | |
707 | * have any real values, like transferred bytes or error | |
708 | * bits. So we need to just drop these values. | |
709 | */ | |
710 | size = ioread32(&mdev->resp->bytes_transferred); | |
711 | status = ioread32(&mdev->resp->status); | |
712 | ||
713 | msgdma_complete_descriptor(mdev); | |
714 | msgdma_chan_desc_cleanup(mdev); | |
715 | } | |
716 | ||
717 | spin_unlock(&mdev->lock); | |
718 | } | |
719 | ||
720 | /** | |
721 | * msgdma_irq_handler - Altera mSGDMA Interrupt handler | |
722 | * @irq: IRQ number | |
723 | * @data: Pointer to the Altera mSGDMA device structure | |
724 | * | |
725 | * Return: IRQ_HANDLED/IRQ_NONE | |
726 | */ | |
727 | static irqreturn_t msgdma_irq_handler(int irq, void *data) | |
728 | { | |
729 | struct msgdma_device *mdev = data; | |
730 | u32 status; | |
731 | ||
732 | status = ioread32(&mdev->csr->status); | |
733 | if ((status & MSGDMA_CSR_STAT_BUSY) == 0) { | |
734 | /* Start next transfer if the DMA controller is idle */ | |
735 | spin_lock(&mdev->lock); | |
736 | mdev->idle = true; | |
737 | msgdma_start_transfer(mdev); | |
738 | spin_unlock(&mdev->lock); | |
739 | } | |
740 | ||
741 | tasklet_schedule(&mdev->irq_tasklet); | |
742 | ||
743 | /* Clear interrupt in mSGDMA controller */ | |
744 | iowrite32(MSGDMA_CSR_STAT_IRQ, &mdev->csr->status); | |
745 | ||
746 | return IRQ_HANDLED; | |
747 | } | |
748 | ||
749 | /** | |
750 | * msgdma_chan_remove - Channel remove function | |
751 | * @mdev: Pointer to the Altera mSGDMA device structure | |
752 | */ | |
753 | static void msgdma_dev_remove(struct msgdma_device *mdev) | |
754 | { | |
755 | if (!mdev) | |
756 | return; | |
757 | ||
758 | devm_free_irq(mdev->dev, mdev->irq, mdev); | |
759 | tasklet_kill(&mdev->irq_tasklet); | |
760 | list_del(&mdev->dmachan.device_node); | |
761 | } | |
762 | ||
763 | static int request_and_map(struct platform_device *pdev, const char *name, | |
764 | struct resource **res, void __iomem **ptr) | |
765 | { | |
766 | struct resource *region; | |
767 | struct device *device = &pdev->dev; | |
768 | ||
769 | *res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name); | |
770 | if (*res == NULL) { | |
771 | dev_err(device, "resource %s not defined\n", name); | |
772 | return -ENODEV; | |
773 | } | |
774 | ||
775 | region = devm_request_mem_region(device, (*res)->start, | |
776 | resource_size(*res), dev_name(device)); | |
777 | if (region == NULL) { | |
778 | dev_err(device, "unable to request %s\n", name); | |
779 | return -EBUSY; | |
780 | } | |
781 | ||
782 | *ptr = devm_ioremap_nocache(device, region->start, | |
783 | resource_size(region)); | |
784 | if (*ptr == NULL) { | |
785 | dev_err(device, "ioremap_nocache of %s failed!", name); | |
786 | return -ENOMEM; | |
787 | } | |
788 | ||
789 | return 0; | |
790 | } | |
791 | ||
792 | /** | |
793 | * msgdma_probe - Driver probe function | |
794 | * @pdev: Pointer to the platform_device structure | |
795 | * | |
796 | * Return: '0' on success and failure value on error | |
797 | */ | |
798 | static int msgdma_probe(struct platform_device *pdev) | |
799 | { | |
800 | struct msgdma_device *mdev; | |
801 | struct dma_device *dma_dev; | |
802 | struct resource *dma_res; | |
803 | int ret; | |
804 | ||
805 | mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_NOWAIT); | |
806 | if (!mdev) | |
807 | return -ENOMEM; | |
808 | ||
809 | mdev->dev = &pdev->dev; | |
810 | ||
811 | /* Map CSR space */ | |
812 | ret = request_and_map(pdev, "csr", &dma_res, (void **)&mdev->csr); | |
813 | if (ret) | |
814 | return ret; | |
815 | ||
816 | /* Map (extended) descriptor space */ | |
817 | ret = request_and_map(pdev, "desc", &dma_res, (void **)&mdev->desc); | |
818 | if (ret) | |
819 | return ret; | |
820 | ||
821 | /* Map response space */ | |
822 | ret = request_and_map(pdev, "resp", &dma_res, (void **)&mdev->resp); | |
823 | if (ret) | |
824 | return ret; | |
825 | ||
826 | platform_set_drvdata(pdev, mdev); | |
827 | ||
828 | /* Get interrupt nr from platform data */ | |
829 | mdev->irq = platform_get_irq(pdev, 0); | |
830 | if (mdev->irq < 0) | |
831 | return -ENXIO; | |
832 | ||
833 | ret = devm_request_irq(&pdev->dev, mdev->irq, msgdma_irq_handler, | |
834 | 0, dev_name(&pdev->dev), mdev); | |
835 | if (ret) | |
836 | return ret; | |
837 | ||
838 | tasklet_init(&mdev->irq_tasklet, msgdma_tasklet, (unsigned long)mdev); | |
839 | ||
840 | dma_cookie_init(&mdev->dmachan); | |
841 | ||
842 | spin_lock_init(&mdev->lock); | |
843 | ||
844 | INIT_LIST_HEAD(&mdev->active_list); | |
845 | INIT_LIST_HEAD(&mdev->pending_list); | |
846 | INIT_LIST_HEAD(&mdev->done_list); | |
847 | INIT_LIST_HEAD(&mdev->free_list); | |
848 | ||
849 | dma_dev = &mdev->dmadev; | |
850 | ||
851 | /* Set DMA capabilities */ | |
852 | dma_cap_zero(dma_dev->cap_mask); | |
853 | dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); | |
a85c6f1b SR |
854 | dma_cap_set(DMA_SLAVE, dma_dev->cap_mask); |
855 | ||
856 | dma_dev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); | |
857 | dma_dev->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); | |
858 | dma_dev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM) | | |
859 | BIT(DMA_MEM_TO_MEM); | |
860 | dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; | |
861 | ||
862 | /* Init DMA link list */ | |
863 | INIT_LIST_HEAD(&dma_dev->channels); | |
864 | ||
865 | /* Set base routines */ | |
866 | dma_dev->device_tx_status = dma_cookie_status; | |
867 | dma_dev->device_issue_pending = msgdma_issue_pending; | |
868 | dma_dev->dev = &pdev->dev; | |
869 | ||
870 | dma_dev->copy_align = DMAENGINE_ALIGN_4_BYTES; | |
871 | dma_dev->device_prep_dma_memcpy = msgdma_prep_memcpy; | |
a85c6f1b SR |
872 | dma_dev->device_prep_slave_sg = msgdma_prep_slave_sg; |
873 | dma_dev->device_config = msgdma_dma_config; | |
874 | ||
875 | dma_dev->device_alloc_chan_resources = msgdma_alloc_chan_resources; | |
876 | dma_dev->device_free_chan_resources = msgdma_free_chan_resources; | |
877 | ||
878 | mdev->dmachan.device = dma_dev; | |
879 | list_add_tail(&mdev->dmachan.device_node, &dma_dev->channels); | |
880 | ||
881 | /* Set DMA mask to 64 bits */ | |
882 | ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); | |
883 | if (ret) { | |
884 | dev_warn(&pdev->dev, "unable to set coherent mask to 64"); | |
885 | ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); | |
886 | if (ret) | |
887 | goto fail; | |
888 | } | |
889 | ||
890 | msgdma_reset(mdev); | |
891 | ||
892 | ret = dma_async_device_register(dma_dev); | |
893 | if (ret) | |
894 | goto fail; | |
895 | ||
896 | dev_notice(&pdev->dev, "Altera mSGDMA driver probe success\n"); | |
897 | ||
898 | return 0; | |
899 | ||
900 | fail: | |
901 | msgdma_dev_remove(mdev); | |
902 | ||
903 | return ret; | |
904 | } | |
905 | ||
906 | /** | |
907 | * msgdma_dma_remove - Driver remove function | |
908 | * @pdev: Pointer to the platform_device structure | |
909 | * | |
910 | * Return: Always '0' | |
911 | */ | |
912 | static int msgdma_remove(struct platform_device *pdev) | |
913 | { | |
914 | struct msgdma_device *mdev = platform_get_drvdata(pdev); | |
915 | ||
916 | dma_async_device_unregister(&mdev->dmadev); | |
917 | msgdma_dev_remove(mdev); | |
918 | ||
919 | dev_notice(&pdev->dev, "Altera mSGDMA driver removed\n"); | |
920 | ||
921 | return 0; | |
922 | } | |
923 | ||
924 | static struct platform_driver msgdma_driver = { | |
925 | .driver = { | |
926 | .name = "altera-msgdma", | |
927 | }, | |
928 | .probe = msgdma_probe, | |
929 | .remove = msgdma_remove, | |
930 | }; | |
931 | ||
932 | module_platform_driver(msgdma_driver); | |
933 | ||
934 | MODULE_ALIAS("platform:altera-msgdma"); | |
935 | MODULE_DESCRIPTION("Altera mSGDMA driver"); | |
936 | MODULE_AUTHOR("Stefan Roese <sr@denx.de>"); | |
937 | MODULE_LICENSE("GPL"); |