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1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Spreadtrum Communications Inc.
3
4#include <linux/clk.h>
5#include <linux/dmaengine.h>
6#include <linux/dma-mapping.h>
7#include <linux/dma/sprd-dma.h>
8#include <linux/interrupt.h>
9#include <linux/io.h>
10#include <linux/iopoll.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/of_device.h>
15#include <linux/of_dma.h>
16#include <linux/platform_device.h>
17#include <linux/pm_runtime.h>
18#include <linux/spi/spi.h>
19
20#define SPRD_SPI_TXD 0x0
21#define SPRD_SPI_CLKD 0x4
22#define SPRD_SPI_CTL0 0x8
23#define SPRD_SPI_CTL1 0xc
24#define SPRD_SPI_CTL2 0x10
25#define SPRD_SPI_CTL3 0x14
26#define SPRD_SPI_CTL4 0x18
27#define SPRD_SPI_CTL5 0x1c
28#define SPRD_SPI_INT_EN 0x20
29#define SPRD_SPI_INT_CLR 0x24
30#define SPRD_SPI_INT_RAW_STS 0x28
31#define SPRD_SPI_INT_MASK_STS 0x2c
32#define SPRD_SPI_STS1 0x30
33#define SPRD_SPI_STS2 0x34
34#define SPRD_SPI_DSP_WAIT 0x38
35#define SPRD_SPI_STS3 0x3c
36#define SPRD_SPI_CTL6 0x40
37#define SPRD_SPI_STS4 0x44
38#define SPRD_SPI_FIFO_RST 0x48
39#define SPRD_SPI_CTL7 0x4c
40#define SPRD_SPI_STS5 0x50
41#define SPRD_SPI_CTL8 0x54
42#define SPRD_SPI_CTL9 0x58
43#define SPRD_SPI_CTL10 0x5c
44#define SPRD_SPI_CTL11 0x60
45#define SPRD_SPI_CTL12 0x64
46#define SPRD_SPI_STS6 0x68
47#define SPRD_SPI_STS7 0x6c
48#define SPRD_SPI_STS8 0x70
49#define SPRD_SPI_STS9 0x74
50
51/* Bits & mask definition for register CTL0 */
52#define SPRD_SPI_SCK_REV BIT(13)
53#define SPRD_SPI_NG_TX BIT(1)
54#define SPRD_SPI_NG_RX BIT(0)
55#define SPRD_SPI_CHNL_LEN_MASK GENMASK(4, 0)
56#define SPRD_SPI_CSN_MASK GENMASK(11, 8)
57#define SPRD_SPI_CS0_VALID BIT(8)
58
59/* Bits & mask definition for register SPI_INT_EN */
60#define SPRD_SPI_TX_END_INT_EN BIT(8)
61#define SPRD_SPI_RX_END_INT_EN BIT(9)
62
63/* Bits & mask definition for register SPI_INT_RAW_STS */
64#define SPRD_SPI_TX_END_RAW BIT(8)
65#define SPRD_SPI_RX_END_RAW BIT(9)
66
67/* Bits & mask definition for register SPI_INT_CLR */
68#define SPRD_SPI_TX_END_CLR BIT(8)
69#define SPRD_SPI_RX_END_CLR BIT(9)
70
71/* Bits & mask definition for register INT_MASK_STS */
72#define SPRD_SPI_MASK_RX_END BIT(9)
73#define SPRD_SPI_MASK_TX_END BIT(8)
74
75/* Bits & mask definition for register STS2 */
76#define SPRD_SPI_TX_BUSY BIT(8)
77
78/* Bits & mask definition for register CTL1 */
79#define SPRD_SPI_RX_MODE BIT(12)
80#define SPRD_SPI_TX_MODE BIT(13)
81#define SPRD_SPI_RTX_MD_MASK GENMASK(13, 12)
82
83/* Bits & mask definition for register CTL2 */
84#define SPRD_SPI_DMA_EN BIT(6)
85
86/* Bits & mask definition for register CTL4 */
87#define SPRD_SPI_START_RX BIT(9)
88#define SPRD_SPI_ONLY_RECV_MASK GENMASK(8, 0)
89
90/* Bits & mask definition for register SPI_INT_CLR */
91#define SPRD_SPI_RX_END_INT_CLR BIT(9)
92#define SPRD_SPI_TX_END_INT_CLR BIT(8)
93
94/* Bits & mask definition for register SPI_INT_RAW */
95#define SPRD_SPI_RX_END_IRQ BIT(9)
96#define SPRD_SPI_TX_END_IRQ BIT(8)
97
98/* Bits & mask definition for register CTL12 */
99#define SPRD_SPI_SW_RX_REQ BIT(0)
100#define SPRD_SPI_SW_TX_REQ BIT(1)
101
102/* Bits & mask definition for register CTL7 */
103#define SPRD_SPI_DATA_LINE2_EN BIT(15)
104#define SPRD_SPI_MODE_MASK GENMASK(5, 3)
105#define SPRD_SPI_MODE_OFFSET 3
106#define SPRD_SPI_3WIRE_MODE 4
107#define SPRD_SPI_4WIRE_MODE 0
108
109/* Bits & mask definition for register CTL8 */
110#define SPRD_SPI_TX_MAX_LEN_MASK GENMASK(19, 0)
111#define SPRD_SPI_TX_LEN_H_MASK GENMASK(3, 0)
112#define SPRD_SPI_TX_LEN_H_OFFSET 16
113
114/* Bits & mask definition for register CTL9 */
115#define SPRD_SPI_TX_LEN_L_MASK GENMASK(15, 0)
116
117/* Bits & mask definition for register CTL10 */
118#define SPRD_SPI_RX_MAX_LEN_MASK GENMASK(19, 0)
119#define SPRD_SPI_RX_LEN_H_MASK GENMASK(3, 0)
120#define SPRD_SPI_RX_LEN_H_OFFSET 16
121
122/* Bits & mask definition for register CTL11 */
123#define SPRD_SPI_RX_LEN_L_MASK GENMASK(15, 0)
124
125/* Default & maximum word delay cycles */
126#define SPRD_SPI_MIN_DELAY_CYCLE 14
127#define SPRD_SPI_MAX_DELAY_CYCLE 130
128
129#define SPRD_SPI_FIFO_SIZE 32
130#define SPRD_SPI_CHIP_CS_NUM 0x4
131#define SPRD_SPI_CHNL_LEN 2
132#define SPRD_SPI_DEFAULT_SOURCE 26000000
133#define SPRD_SPI_MAX_SPEED_HZ 48000000
134#define SPRD_SPI_AUTOSUSPEND_DELAY 100
135#define SPRD_SPI_DMA_STEP 8
136
137enum sprd_spi_dma_channel {
138 SPRD_SPI_RX,
139 SPRD_SPI_TX,
140 SPRD_SPI_MAX,
141};
142
143struct sprd_spi_dma {
144 bool enable;
145 struct dma_chan *dma_chan[SPRD_SPI_MAX];
146 enum dma_slave_buswidth width;
147 u32 fragmens_len;
148 u32 rx_len;
149};
150
151struct sprd_spi {
152 void __iomem *base;
153 phys_addr_t phy_base;
154 struct device *dev;
155 struct clk *clk;
156 int irq;
157 u32 src_clk;
158 u32 hw_mode;
159 u32 trans_len;
160 u32 trans_mode;
161 u32 word_delay;
162 u32 hw_speed_hz;
163 u32 len;
164 int status;
165 struct sprd_spi_dma dma;
166 struct completion xfer_completion;
167 const void *tx_buf;
168 void *rx_buf;
169 int (*read_bufs)(struct sprd_spi *ss, u32 len);
170 int (*write_bufs)(struct sprd_spi *ss, u32 len);
171};
172
173static u32 sprd_spi_transfer_max_timeout(struct sprd_spi *ss,
174 struct spi_transfer *t)
175{
176 /*
177 * The time spent on transmission of the full FIFO data is the maximum
178 * SPI transmission time.
179 */
180 u32 size = t->bits_per_word * SPRD_SPI_FIFO_SIZE;
181 u32 bit_time_us = DIV_ROUND_UP(USEC_PER_SEC, ss->hw_speed_hz);
182 u32 total_time_us = size * bit_time_us;
183 /*
184 * There is an interval between data and the data in our SPI hardware,
185 * so the total transmission time need add the interval time.
186 */
187 u32 interval_cycle = SPRD_SPI_FIFO_SIZE * ss->word_delay;
188 u32 interval_time_us = DIV_ROUND_UP(interval_cycle * USEC_PER_SEC,
189 ss->src_clk);
190
191 return total_time_us + interval_time_us;
192}
193
194static int sprd_spi_wait_for_tx_end(struct sprd_spi *ss, struct spi_transfer *t)
195{
196 u32 val, us;
197 int ret;
198
199 us = sprd_spi_transfer_max_timeout(ss, t);
200 ret = readl_relaxed_poll_timeout(ss->base + SPRD_SPI_INT_RAW_STS, val,
201 val & SPRD_SPI_TX_END_IRQ, 0, us);
202 if (ret) {
203 dev_err(ss->dev, "SPI error, spi send timeout!\n");
204 return ret;
205 }
206
207 ret = readl_relaxed_poll_timeout(ss->base + SPRD_SPI_STS2, val,
208 !(val & SPRD_SPI_TX_BUSY), 0, us);
209 if (ret) {
210 dev_err(ss->dev, "SPI error, spi busy timeout!\n");
211 return ret;
212 }
213
214 writel_relaxed(SPRD_SPI_TX_END_INT_CLR, ss->base + SPRD_SPI_INT_CLR);
215
216 return 0;
217}
218
219static int sprd_spi_wait_for_rx_end(struct sprd_spi *ss, struct spi_transfer *t)
220{
221 u32 val, us;
222 int ret;
223
224 us = sprd_spi_transfer_max_timeout(ss, t);
225 ret = readl_relaxed_poll_timeout(ss->base + SPRD_SPI_INT_RAW_STS, val,
226 val & SPRD_SPI_RX_END_IRQ, 0, us);
227 if (ret) {
228 dev_err(ss->dev, "SPI error, spi rx timeout!\n");
229 return ret;
230 }
231
232 writel_relaxed(SPRD_SPI_RX_END_INT_CLR, ss->base + SPRD_SPI_INT_CLR);
233
234 return 0;
235}
236
237static void sprd_spi_tx_req(struct sprd_spi *ss)
238{
239 writel_relaxed(SPRD_SPI_SW_TX_REQ, ss->base + SPRD_SPI_CTL12);
240}
241
242static void sprd_spi_rx_req(struct sprd_spi *ss)
243{
244 writel_relaxed(SPRD_SPI_SW_RX_REQ, ss->base + SPRD_SPI_CTL12);
245}
246
247static void sprd_spi_enter_idle(struct sprd_spi *ss)
248{
249 u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL1);
250
251 val &= ~SPRD_SPI_RTX_MD_MASK;
252 writel_relaxed(val, ss->base + SPRD_SPI_CTL1);
253}
254
255static void sprd_spi_set_transfer_bits(struct sprd_spi *ss, u32 bits)
256{
257 u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL0);
258
259 /* Set the valid bits for every transaction */
260 val &= ~(SPRD_SPI_CHNL_LEN_MASK << SPRD_SPI_CHNL_LEN);
261 val |= bits << SPRD_SPI_CHNL_LEN;
262 writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
263}
264
265static void sprd_spi_set_tx_length(struct sprd_spi *ss, u32 length)
266{
267 u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL8);
268
269 length &= SPRD_SPI_TX_MAX_LEN_MASK;
270 val &= ~SPRD_SPI_TX_LEN_H_MASK;
271 val |= length >> SPRD_SPI_TX_LEN_H_OFFSET;
272 writel_relaxed(val, ss->base + SPRD_SPI_CTL8);
273
274 val = length & SPRD_SPI_TX_LEN_L_MASK;
275 writel_relaxed(val, ss->base + SPRD_SPI_CTL9);
276}
277
278static void sprd_spi_set_rx_length(struct sprd_spi *ss, u32 length)
279{
280 u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL10);
281
282 length &= SPRD_SPI_RX_MAX_LEN_MASK;
283 val &= ~SPRD_SPI_RX_LEN_H_MASK;
284 val |= length >> SPRD_SPI_RX_LEN_H_OFFSET;
285 writel_relaxed(val, ss->base + SPRD_SPI_CTL10);
286
287 val = length & SPRD_SPI_RX_LEN_L_MASK;
288 writel_relaxed(val, ss->base + SPRD_SPI_CTL11);
289}
290
291static void sprd_spi_chipselect(struct spi_device *sdev, bool cs)
292{
293 struct spi_controller *sctlr = sdev->controller;
294 struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
295 u32 val;
296
297 val = readl_relaxed(ss->base + SPRD_SPI_CTL0);
298 /* The SPI controller will pull down CS pin if cs is 0 */
299 if (!cs) {
300 val &= ~SPRD_SPI_CS0_VALID;
301 writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
302 } else {
303 val |= SPRD_SPI_CSN_MASK;
304 writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
305 }
306}
307
308static int sprd_spi_write_only_receive(struct sprd_spi *ss, u32 len)
309{
310 u32 val;
311
312 /* Clear the start receive bit and reset receive data number */
313 val = readl_relaxed(ss->base + SPRD_SPI_CTL4);
314 val &= ~(SPRD_SPI_START_RX | SPRD_SPI_ONLY_RECV_MASK);
315 writel_relaxed(val, ss->base + SPRD_SPI_CTL4);
316
317 /* Set the receive data length */
318 val = readl_relaxed(ss->base + SPRD_SPI_CTL4);
319 val |= len & SPRD_SPI_ONLY_RECV_MASK;
320 writel_relaxed(val, ss->base + SPRD_SPI_CTL4);
321
322 /* Trigger to receive data */
323 val = readl_relaxed(ss->base + SPRD_SPI_CTL4);
324 val |= SPRD_SPI_START_RX;
325 writel_relaxed(val, ss->base + SPRD_SPI_CTL4);
326
327 return len;
328}
329
330static int sprd_spi_write_bufs_u8(struct sprd_spi *ss, u32 len)
331{
332 u8 *tx_p = (u8 *)ss->tx_buf;
333 int i;
334
335 for (i = 0; i < len; i++)
336 writeb_relaxed(tx_p[i], ss->base + SPRD_SPI_TXD);
337
338 ss->tx_buf += i;
339 return i;
340}
341
342static int sprd_spi_write_bufs_u16(struct sprd_spi *ss, u32 len)
343{
344 u16 *tx_p = (u16 *)ss->tx_buf;
345 int i;
346
347 for (i = 0; i < len; i++)
348 writew_relaxed(tx_p[i], ss->base + SPRD_SPI_TXD);
349
350 ss->tx_buf += i << 1;
351 return i << 1;
352}
353
354static int sprd_spi_write_bufs_u32(struct sprd_spi *ss, u32 len)
355{
356 u32 *tx_p = (u32 *)ss->tx_buf;
357 int i;
358
359 for (i = 0; i < len; i++)
360 writel_relaxed(tx_p[i], ss->base + SPRD_SPI_TXD);
361
362 ss->tx_buf += i << 2;
363 return i << 2;
364}
365
366static int sprd_spi_read_bufs_u8(struct sprd_spi *ss, u32 len)
367{
368 u8 *rx_p = (u8 *)ss->rx_buf;
369 int i;
370
371 for (i = 0; i < len; i++)
372 rx_p[i] = readb_relaxed(ss->base + SPRD_SPI_TXD);
373
374 ss->rx_buf += i;
375 return i;
376}
377
378static int sprd_spi_read_bufs_u16(struct sprd_spi *ss, u32 len)
379{
380 u16 *rx_p = (u16 *)ss->rx_buf;
381 int i;
382
383 for (i = 0; i < len; i++)
384 rx_p[i] = readw_relaxed(ss->base + SPRD_SPI_TXD);
385
386 ss->rx_buf += i << 1;
387 return i << 1;
388}
389
390static int sprd_spi_read_bufs_u32(struct sprd_spi *ss, u32 len)
391{
392 u32 *rx_p = (u32 *)ss->rx_buf;
393 int i;
394
395 for (i = 0; i < len; i++)
396 rx_p[i] = readl_relaxed(ss->base + SPRD_SPI_TXD);
397
398 ss->rx_buf += i << 2;
399 return i << 2;
400}
401
402static int sprd_spi_txrx_bufs(struct spi_device *sdev, struct spi_transfer *t)
403{
404 struct sprd_spi *ss = spi_controller_get_devdata(sdev->controller);
405 u32 trans_len = ss->trans_len, len;
406 int ret, write_size = 0, read_size = 0;
407
408 while (trans_len) {
409 len = trans_len > SPRD_SPI_FIFO_SIZE ? SPRD_SPI_FIFO_SIZE :
410 trans_len;
411 if (ss->trans_mode & SPRD_SPI_TX_MODE) {
412 sprd_spi_set_tx_length(ss, len);
413 write_size += ss->write_bufs(ss, len);
414
415 /*
416 * For our 3 wires mode or dual TX line mode, we need
417 * to request the controller to transfer.
418 */
419 if (ss->hw_mode & SPI_3WIRE || ss->hw_mode & SPI_TX_DUAL)
420 sprd_spi_tx_req(ss);
421
422 ret = sprd_spi_wait_for_tx_end(ss, t);
423 } else {
424 sprd_spi_set_rx_length(ss, len);
425
426 /*
427 * For our 3 wires mode or dual TX line mode, we need
428 * to request the controller to read.
429 */
430 if (ss->hw_mode & SPI_3WIRE || ss->hw_mode & SPI_TX_DUAL)
431 sprd_spi_rx_req(ss);
432 else
433 write_size += ss->write_bufs(ss, len);
434
435 ret = sprd_spi_wait_for_rx_end(ss, t);
436 }
437
438 if (ret)
439 goto complete;
440
441 if (ss->trans_mode & SPRD_SPI_RX_MODE)
442 read_size += ss->read_bufs(ss, len);
443
444 trans_len -= len;
445 }
446
447 if (ss->trans_mode & SPRD_SPI_TX_MODE)
448 ret = write_size;
449 else
450 ret = read_size;
451complete:
452 sprd_spi_enter_idle(ss);
453
454 return ret;
455}
456
457static void sprd_spi_irq_enable(struct sprd_spi *ss)
458{
459 u32 val;
460
461 /* Clear interrupt status before enabling interrupt. */
462 writel_relaxed(SPRD_SPI_TX_END_CLR | SPRD_SPI_RX_END_CLR,
463 ss->base + SPRD_SPI_INT_CLR);
464 /* Enable SPI interrupt only in DMA mode. */
465 val = readl_relaxed(ss->base + SPRD_SPI_INT_EN);
466 writel_relaxed(val | SPRD_SPI_TX_END_INT_EN |
467 SPRD_SPI_RX_END_INT_EN,
468 ss->base + SPRD_SPI_INT_EN);
469}
470
471static void sprd_spi_irq_disable(struct sprd_spi *ss)
472{
473 writel_relaxed(0, ss->base + SPRD_SPI_INT_EN);
474}
475
476static void sprd_spi_dma_enable(struct sprd_spi *ss, bool enable)
477{
478 u32 val = readl_relaxed(ss->base + SPRD_SPI_CTL2);
479
480 if (enable)
481 val |= SPRD_SPI_DMA_EN;
482 else
483 val &= ~SPRD_SPI_DMA_EN;
484
485 writel_relaxed(val, ss->base + SPRD_SPI_CTL2);
486}
487
488static int sprd_spi_dma_submit(struct dma_chan *dma_chan,
489 struct dma_slave_config *c,
490 struct sg_table *sg,
491 enum dma_transfer_direction dir)
492{
493 struct dma_async_tx_descriptor *desc;
494 dma_cookie_t cookie;
495 unsigned long flags;
496 int ret;
497
498 ret = dmaengine_slave_config(dma_chan, c);
499 if (ret < 0)
500 return ret;
501
502 flags = SPRD_DMA_FLAGS(SPRD_DMA_CHN_MODE_NONE, SPRD_DMA_NO_TRG,
503 SPRD_DMA_FRAG_REQ, SPRD_DMA_TRANS_INT);
504 desc = dmaengine_prep_slave_sg(dma_chan, sg->sgl, sg->nents, dir, flags);
505 if (!desc)
506 return -ENODEV;
507
508 cookie = dmaengine_submit(desc);
509 if (dma_submit_error(cookie))
510 return dma_submit_error(cookie);
511
512 dma_async_issue_pending(dma_chan);
513
514 return 0;
515}
516
517static int sprd_spi_dma_rx_config(struct sprd_spi *ss, struct spi_transfer *t)
518{
519 struct dma_chan *dma_chan = ss->dma.dma_chan[SPRD_SPI_RX];
520 struct dma_slave_config config = {
521 .src_addr = ss->phy_base,
522 .src_addr_width = ss->dma.width,
523 .dst_addr_width = ss->dma.width,
524 .dst_maxburst = ss->dma.fragmens_len,
525 };
526 int ret;
527
528 ret = sprd_spi_dma_submit(dma_chan, &config, &t->rx_sg, DMA_DEV_TO_MEM);
529 if (ret)
530 return ret;
531
532 return ss->dma.rx_len;
533}
534
535static int sprd_spi_dma_tx_config(struct sprd_spi *ss, struct spi_transfer *t)
536{
537 struct dma_chan *dma_chan = ss->dma.dma_chan[SPRD_SPI_TX];
538 struct dma_slave_config config = {
539 .dst_addr = ss->phy_base,
540 .src_addr_width = ss->dma.width,
541 .dst_addr_width = ss->dma.width,
542 .src_maxburst = ss->dma.fragmens_len,
543 };
544 int ret;
545
546 ret = sprd_spi_dma_submit(dma_chan, &config, &t->tx_sg, DMA_MEM_TO_DEV);
547 if (ret)
548 return ret;
549
550 return t->len;
551}
552
553static int sprd_spi_dma_request(struct sprd_spi *ss)
554{
555 ss->dma.dma_chan[SPRD_SPI_RX] = dma_request_chan(ss->dev, "rx_chn");
556 if (IS_ERR_OR_NULL(ss->dma.dma_chan[SPRD_SPI_RX]))
557 return dev_err_probe(ss->dev, PTR_ERR(ss->dma.dma_chan[SPRD_SPI_RX]),
558 "request RX DMA channel failed!\n");
559
560 ss->dma.dma_chan[SPRD_SPI_TX] = dma_request_chan(ss->dev, "tx_chn");
561 if (IS_ERR_OR_NULL(ss->dma.dma_chan[SPRD_SPI_TX])) {
562 dma_release_channel(ss->dma.dma_chan[SPRD_SPI_RX]);
563 return dev_err_probe(ss->dev, PTR_ERR(ss->dma.dma_chan[SPRD_SPI_TX]),
564 "request TX DMA channel failed!\n");
565 }
566
567 return 0;
568}
569
570static void sprd_spi_dma_release(struct sprd_spi *ss)
571{
572 if (ss->dma.dma_chan[SPRD_SPI_RX])
573 dma_release_channel(ss->dma.dma_chan[SPRD_SPI_RX]);
574
575 if (ss->dma.dma_chan[SPRD_SPI_TX])
576 dma_release_channel(ss->dma.dma_chan[SPRD_SPI_TX]);
577}
578
579static int sprd_spi_dma_txrx_bufs(struct spi_device *sdev,
580 struct spi_transfer *t)
581{
582 struct sprd_spi *ss = spi_master_get_devdata(sdev->master);
583 u32 trans_len = ss->trans_len;
584 int ret, write_size = 0;
585
586 reinit_completion(&ss->xfer_completion);
587 sprd_spi_irq_enable(ss);
588 if (ss->trans_mode & SPRD_SPI_TX_MODE) {
589 write_size = sprd_spi_dma_tx_config(ss, t);
590 sprd_spi_set_tx_length(ss, trans_len);
591
592 /*
593 * For our 3 wires mode or dual TX line mode, we need
594 * to request the controller to transfer.
595 */
596 if (ss->hw_mode & SPI_3WIRE || ss->hw_mode & SPI_TX_DUAL)
597 sprd_spi_tx_req(ss);
598 } else {
599 sprd_spi_set_rx_length(ss, trans_len);
600
601 /*
602 * For our 3 wires mode or dual TX line mode, we need
603 * to request the controller to read.
604 */
605 if (ss->hw_mode & SPI_3WIRE || ss->hw_mode & SPI_TX_DUAL)
606 sprd_spi_rx_req(ss);
607 else
608 write_size = ss->write_bufs(ss, trans_len);
609 }
610
611 if (write_size < 0) {
612 ret = write_size;
613 dev_err(ss->dev, "failed to write, ret = %d\n", ret);
614 goto trans_complete;
615 }
616
617 if (ss->trans_mode & SPRD_SPI_RX_MODE) {
618 /*
619 * Set up the DMA receive data length, which must be an
620 * integral multiple of fragment length. But when the length
621 * of received data is less than fragment length, DMA can be
622 * configured to receive data according to the actual length
623 * of received data.
624 */
625 ss->dma.rx_len = t->len > ss->dma.fragmens_len ?
626 (t->len - t->len % ss->dma.fragmens_len) :
627 t->len;
628 ret = sprd_spi_dma_rx_config(ss, t);
629 if (ret < 0) {
630 dev_err(&sdev->dev,
631 "failed to configure rx DMA, ret = %d\n", ret);
632 goto trans_complete;
633 }
634 }
635
636 sprd_spi_dma_enable(ss, true);
637 wait_for_completion(&(ss->xfer_completion));
638
639 if (ss->trans_mode & SPRD_SPI_TX_MODE)
640 ret = write_size;
641 else
642 ret = ss->dma.rx_len;
643
644trans_complete:
645 sprd_spi_dma_enable(ss, false);
646 sprd_spi_enter_idle(ss);
647 sprd_spi_irq_disable(ss);
648
649 return ret;
650}
651
652static void sprd_spi_set_speed(struct sprd_spi *ss, u32 speed_hz)
653{
654 /*
655 * From SPI datasheet, the prescale calculation formula:
656 * prescale = SPI source clock / (2 * SPI_freq) - 1;
657 */
658 u32 clk_div = DIV_ROUND_UP(ss->src_clk, speed_hz << 1) - 1;
659
660 /* Save the real hardware speed */
661 ss->hw_speed_hz = (ss->src_clk >> 1) / (clk_div + 1);
662 writel_relaxed(clk_div, ss->base + SPRD_SPI_CLKD);
663}
664
665static int sprd_spi_init_hw(struct sprd_spi *ss, struct spi_transfer *t)
666{
667 struct spi_delay *d = &t->word_delay;
668 u16 word_delay, interval;
669 u32 val;
670
671 if (d->unit != SPI_DELAY_UNIT_SCK)
672 return -EINVAL;
673
674 val = readl_relaxed(ss->base + SPRD_SPI_CTL0);
675 val &= ~(SPRD_SPI_SCK_REV | SPRD_SPI_NG_TX | SPRD_SPI_NG_RX);
676 /* Set default chip selection, clock phase and clock polarity */
677 val |= ss->hw_mode & SPI_CPHA ? SPRD_SPI_NG_RX : SPRD_SPI_NG_TX;
678 val |= ss->hw_mode & SPI_CPOL ? SPRD_SPI_SCK_REV : 0;
679 writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
680
681 /*
682 * Set the intervals of two SPI frames, and the inteval calculation
683 * formula as below per datasheet:
684 * interval time (source clock cycles) = interval * 4 + 10.
685 */
686 word_delay = clamp_t(u16, d->value, SPRD_SPI_MIN_DELAY_CYCLE,
687 SPRD_SPI_MAX_DELAY_CYCLE);
688 interval = DIV_ROUND_UP(word_delay - 10, 4);
689 ss->word_delay = interval * 4 + 10;
690 writel_relaxed(interval, ss->base + SPRD_SPI_CTL5);
691
692 /* Reset SPI fifo */
693 writel_relaxed(1, ss->base + SPRD_SPI_FIFO_RST);
694 writel_relaxed(0, ss->base + SPRD_SPI_FIFO_RST);
695
696 /* Set SPI work mode */
697 val = readl_relaxed(ss->base + SPRD_SPI_CTL7);
698 val &= ~SPRD_SPI_MODE_MASK;
699
700 if (ss->hw_mode & SPI_3WIRE)
701 val |= SPRD_SPI_3WIRE_MODE << SPRD_SPI_MODE_OFFSET;
702 else
703 val |= SPRD_SPI_4WIRE_MODE << SPRD_SPI_MODE_OFFSET;
704
705 if (ss->hw_mode & SPI_TX_DUAL)
706 val |= SPRD_SPI_DATA_LINE2_EN;
707 else
708 val &= ~SPRD_SPI_DATA_LINE2_EN;
709
710 writel_relaxed(val, ss->base + SPRD_SPI_CTL7);
711
712 return 0;
713}
714
715static int sprd_spi_setup_transfer(struct spi_device *sdev,
716 struct spi_transfer *t)
717{
718 struct sprd_spi *ss = spi_controller_get_devdata(sdev->controller);
719 u8 bits_per_word = t->bits_per_word;
720 u32 val, mode = 0;
721 int ret;
722
723 ss->len = t->len;
724 ss->tx_buf = t->tx_buf;
725 ss->rx_buf = t->rx_buf;
726
727 ss->hw_mode = sdev->mode;
728 ret = sprd_spi_init_hw(ss, t);
729 if (ret)
730 return ret;
731
732 /* Set tansfer speed and valid bits */
733 sprd_spi_set_speed(ss, t->speed_hz);
734 sprd_spi_set_transfer_bits(ss, bits_per_word);
735
736 if (bits_per_word > 16)
737 bits_per_word = round_up(bits_per_word, 16);
738 else
739 bits_per_word = round_up(bits_per_word, 8);
740
741 switch (bits_per_word) {
742 case 8:
743 ss->trans_len = t->len;
744 ss->read_bufs = sprd_spi_read_bufs_u8;
745 ss->write_bufs = sprd_spi_write_bufs_u8;
746 ss->dma.width = DMA_SLAVE_BUSWIDTH_1_BYTE;
747 ss->dma.fragmens_len = SPRD_SPI_DMA_STEP;
748 break;
749 case 16:
750 ss->trans_len = t->len >> 1;
751 ss->read_bufs = sprd_spi_read_bufs_u16;
752 ss->write_bufs = sprd_spi_write_bufs_u16;
753 ss->dma.width = DMA_SLAVE_BUSWIDTH_2_BYTES;
754 ss->dma.fragmens_len = SPRD_SPI_DMA_STEP << 1;
755 break;
756 case 32:
757 ss->trans_len = t->len >> 2;
758 ss->read_bufs = sprd_spi_read_bufs_u32;
759 ss->write_bufs = sprd_spi_write_bufs_u32;
760 ss->dma.width = DMA_SLAVE_BUSWIDTH_4_BYTES;
761 ss->dma.fragmens_len = SPRD_SPI_DMA_STEP << 2;
762 break;
763 default:
764 return -EINVAL;
765 }
766
767 /* Set transfer read or write mode */
768 val = readl_relaxed(ss->base + SPRD_SPI_CTL1);
769 val &= ~SPRD_SPI_RTX_MD_MASK;
770 if (t->tx_buf)
771 mode |= SPRD_SPI_TX_MODE;
772 if (t->rx_buf)
773 mode |= SPRD_SPI_RX_MODE;
774
775 writel_relaxed(val | mode, ss->base + SPRD_SPI_CTL1);
776
777 ss->trans_mode = mode;
778
779 /*
780 * If in only receive mode, we need to trigger the SPI controller to
781 * receive data automatically.
782 */
783 if (ss->trans_mode == SPRD_SPI_RX_MODE)
784 ss->write_bufs = sprd_spi_write_only_receive;
785
786 return 0;
787}
788
789static int sprd_spi_transfer_one(struct spi_controller *sctlr,
790 struct spi_device *sdev,
791 struct spi_transfer *t)
792{
793 int ret;
794
795 ret = sprd_spi_setup_transfer(sdev, t);
796 if (ret)
797 goto setup_err;
798
799 if (sctlr->can_dma(sctlr, sdev, t))
800 ret = sprd_spi_dma_txrx_bufs(sdev, t);
801 else
802 ret = sprd_spi_txrx_bufs(sdev, t);
803
804 if (ret == t->len)
805 ret = 0;
806 else if (ret >= 0)
807 ret = -EREMOTEIO;
808
809setup_err:
810 spi_finalize_current_transfer(sctlr);
811
812 return ret;
813}
814
815static irqreturn_t sprd_spi_handle_irq(int irq, void *data)
816{
817 struct sprd_spi *ss = (struct sprd_spi *)data;
818 u32 val = readl_relaxed(ss->base + SPRD_SPI_INT_MASK_STS);
819
820 if (val & SPRD_SPI_MASK_TX_END) {
821 writel_relaxed(SPRD_SPI_TX_END_CLR, ss->base + SPRD_SPI_INT_CLR);
822 if (!(ss->trans_mode & SPRD_SPI_RX_MODE))
823 complete(&ss->xfer_completion);
824
825 return IRQ_HANDLED;
826 }
827
828 if (val & SPRD_SPI_MASK_RX_END) {
829 writel_relaxed(SPRD_SPI_RX_END_CLR, ss->base + SPRD_SPI_INT_CLR);
830 if (ss->dma.rx_len < ss->len) {
831 ss->rx_buf += ss->dma.rx_len;
832 ss->dma.rx_len +=
833 ss->read_bufs(ss, ss->len - ss->dma.rx_len);
834 }
835 complete(&ss->xfer_completion);
836
837 return IRQ_HANDLED;
838 }
839
840 return IRQ_NONE;
841}
842
843static int sprd_spi_irq_init(struct platform_device *pdev, struct sprd_spi *ss)
844{
845 int ret;
846
847 ss->irq = platform_get_irq(pdev, 0);
848 if (ss->irq < 0)
849 return ss->irq;
850
851 ret = devm_request_irq(&pdev->dev, ss->irq, sprd_spi_handle_irq,
852 0, pdev->name, ss);
853 if (ret)
854 dev_err(&pdev->dev, "failed to request spi irq %d, ret = %d\n",
855 ss->irq, ret);
856
857 return ret;
858}
859
860static int sprd_spi_clk_init(struct platform_device *pdev, struct sprd_spi *ss)
861{
862 struct clk *clk_spi, *clk_parent;
863
864 clk_spi = devm_clk_get(&pdev->dev, "spi");
865 if (IS_ERR(clk_spi)) {
866 dev_warn(&pdev->dev, "can't get the spi clock\n");
867 clk_spi = NULL;
868 }
869
870 clk_parent = devm_clk_get(&pdev->dev, "source");
871 if (IS_ERR(clk_parent)) {
872 dev_warn(&pdev->dev, "can't get the source clock\n");
873 clk_parent = NULL;
874 }
875
876 ss->clk = devm_clk_get(&pdev->dev, "enable");
877 if (IS_ERR(ss->clk)) {
878 dev_err(&pdev->dev, "can't get the enable clock\n");
879 return PTR_ERR(ss->clk);
880 }
881
882 if (!clk_set_parent(clk_spi, clk_parent))
883 ss->src_clk = clk_get_rate(clk_spi);
884 else
885 ss->src_clk = SPRD_SPI_DEFAULT_SOURCE;
886
887 return 0;
888}
889
890static bool sprd_spi_can_dma(struct spi_controller *sctlr,
891 struct spi_device *spi, struct spi_transfer *t)
892{
893 struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
894
895 return ss->dma.enable && (t->len > SPRD_SPI_FIFO_SIZE);
896}
897
898static int sprd_spi_dma_init(struct platform_device *pdev, struct sprd_spi *ss)
899{
900 int ret;
901
902 ret = sprd_spi_dma_request(ss);
903 if (ret) {
904 if (ret == -EPROBE_DEFER)
905 return ret;
906
907 dev_warn(&pdev->dev,
908 "failed to request dma, enter no dma mode, ret = %d\n",
909 ret);
910
911 return 0;
912 }
913
914 ss->dma.enable = true;
915
916 return 0;
917}
918
919static int sprd_spi_probe(struct platform_device *pdev)
920{
921 struct spi_controller *sctlr;
922 struct resource *res;
923 struct sprd_spi *ss;
924 int ret;
925
926 pdev->id = of_alias_get_id(pdev->dev.of_node, "spi");
927 sctlr = spi_alloc_master(&pdev->dev, sizeof(*ss));
928 if (!sctlr)
929 return -ENOMEM;
930
931 ss = spi_controller_get_devdata(sctlr);
932 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
933 ss->base = devm_ioremap_resource(&pdev->dev, res);
934 if (IS_ERR(ss->base)) {
935 ret = PTR_ERR(ss->base);
936 goto free_controller;
937 }
938
939 ss->phy_base = res->start;
940 ss->dev = &pdev->dev;
941 sctlr->dev.of_node = pdev->dev.of_node;
942 sctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_3WIRE | SPI_TX_DUAL;
943 sctlr->bus_num = pdev->id;
944 sctlr->set_cs = sprd_spi_chipselect;
945 sctlr->transfer_one = sprd_spi_transfer_one;
946 sctlr->can_dma = sprd_spi_can_dma;
947 sctlr->auto_runtime_pm = true;
948 sctlr->max_speed_hz = min_t(u32, ss->src_clk >> 1,
949 SPRD_SPI_MAX_SPEED_HZ);
950
951 init_completion(&ss->xfer_completion);
952 platform_set_drvdata(pdev, sctlr);
953 ret = sprd_spi_clk_init(pdev, ss);
954 if (ret)
955 goto free_controller;
956
957 ret = sprd_spi_irq_init(pdev, ss);
958 if (ret)
959 goto free_controller;
960
961 ret = sprd_spi_dma_init(pdev, ss);
962 if (ret)
963 goto free_controller;
964
965 ret = clk_prepare_enable(ss->clk);
966 if (ret)
967 goto release_dma;
968
969 ret = pm_runtime_set_active(&pdev->dev);
970 if (ret < 0)
971 goto disable_clk;
972
973 pm_runtime_set_autosuspend_delay(&pdev->dev,
974 SPRD_SPI_AUTOSUSPEND_DELAY);
975 pm_runtime_use_autosuspend(&pdev->dev);
976 pm_runtime_enable(&pdev->dev);
977 ret = pm_runtime_get_sync(&pdev->dev);
978 if (ret < 0) {
979 dev_err(&pdev->dev, "failed to resume SPI controller\n");
980 goto err_rpm_put;
981 }
982
983 ret = devm_spi_register_controller(&pdev->dev, sctlr);
984 if (ret)
985 goto err_rpm_put;
986
987 pm_runtime_mark_last_busy(&pdev->dev);
988 pm_runtime_put_autosuspend(&pdev->dev);
989
990 return 0;
991
992err_rpm_put:
993 pm_runtime_put_noidle(&pdev->dev);
994 pm_runtime_disable(&pdev->dev);
995disable_clk:
996 clk_disable_unprepare(ss->clk);
997release_dma:
998 sprd_spi_dma_release(ss);
999free_controller:
1000 spi_controller_put(sctlr);
1001
1002 return ret;
1003}
1004
1005static int sprd_spi_remove(struct platform_device *pdev)
1006{
1007 struct spi_controller *sctlr = platform_get_drvdata(pdev);
1008 struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
1009 int ret;
1010
1011 ret = pm_runtime_resume_and_get(ss->dev);
1012 if (ret < 0) {
1013 dev_err(ss->dev, "failed to resume SPI controller\n");
1014 return ret;
1015 }
1016
1017 spi_controller_suspend(sctlr);
1018
1019 if (ss->dma.enable)
1020 sprd_spi_dma_release(ss);
1021 clk_disable_unprepare(ss->clk);
1022 pm_runtime_put_noidle(&pdev->dev);
1023 pm_runtime_disable(&pdev->dev);
1024
1025 return 0;
1026}
1027
1028static int __maybe_unused sprd_spi_runtime_suspend(struct device *dev)
1029{
1030 struct spi_controller *sctlr = dev_get_drvdata(dev);
1031 struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
1032
1033 if (ss->dma.enable)
1034 sprd_spi_dma_release(ss);
1035
1036 clk_disable_unprepare(ss->clk);
1037
1038 return 0;
1039}
1040
1041static int __maybe_unused sprd_spi_runtime_resume(struct device *dev)
1042{
1043 struct spi_controller *sctlr = dev_get_drvdata(dev);
1044 struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
1045 int ret;
1046
1047 ret = clk_prepare_enable(ss->clk);
1048 if (ret)
1049 return ret;
1050
1051 if (!ss->dma.enable)
1052 return 0;
1053
1054 ret = sprd_spi_dma_request(ss);
1055 if (ret)
1056 clk_disable_unprepare(ss->clk);
1057
1058 return ret;
1059}
1060
1061static const struct dev_pm_ops sprd_spi_pm_ops = {
1062 SET_RUNTIME_PM_OPS(sprd_spi_runtime_suspend,
1063 sprd_spi_runtime_resume, NULL)
1064};
1065
1066static const struct of_device_id sprd_spi_of_match[] = {
1067 { .compatible = "sprd,sc9860-spi", },
1068 { /* sentinel */ }
1069};
1070MODULE_DEVICE_TABLE(of, sprd_spi_of_match);
1071
1072static struct platform_driver sprd_spi_driver = {
1073 .driver = {
1074 .name = "sprd-spi",
1075 .of_match_table = sprd_spi_of_match,
1076 .pm = &sprd_spi_pm_ops,
1077 },
1078 .probe = sprd_spi_probe,
1079 .remove = sprd_spi_remove,
1080};
1081
1082module_platform_driver(sprd_spi_driver);
1083
1084MODULE_DESCRIPTION("Spreadtrum SPI Controller driver");
1085MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
1086MODULE_LICENSE("GPL v2");