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