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
137 enum sprd_spi_dma_channel {
138 SPRD_SPI_RX,
139 SPRD_SPI_TX,
140 SPRD_SPI_MAX,
141 };
142
143 struct 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
151 struct 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
sprd_spi_transfer_max_timeout(struct sprd_spi * ss,struct spi_transfer * t)173 static 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
sprd_spi_wait_for_tx_end(struct sprd_spi * ss,struct spi_transfer * t)194 static 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
sprd_spi_wait_for_rx_end(struct sprd_spi * ss,struct spi_transfer * t)219 static 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
sprd_spi_tx_req(struct sprd_spi * ss)237 static 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
sprd_spi_rx_req(struct sprd_spi * ss)242 static 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
sprd_spi_enter_idle(struct sprd_spi * ss)247 static 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
sprd_spi_set_transfer_bits(struct sprd_spi * ss,u32 bits)255 static 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
sprd_spi_set_tx_length(struct sprd_spi * ss,u32 length)265 static 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
sprd_spi_set_rx_length(struct sprd_spi * ss,u32 length)278 static 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
sprd_spi_chipselect(struct spi_device * sdev,bool cs)291 static 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
sprd_spi_write_only_receive(struct sprd_spi * ss,u32 len)308 static 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
sprd_spi_write_bufs_u8(struct sprd_spi * ss,u32 len)330 static 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
sprd_spi_write_bufs_u16(struct sprd_spi * ss,u32 len)342 static 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
sprd_spi_write_bufs_u32(struct sprd_spi * ss,u32 len)354 static 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
sprd_spi_read_bufs_u8(struct sprd_spi * ss,u32 len)366 static 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
sprd_spi_read_bufs_u16(struct sprd_spi * ss,u32 len)378 static 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
sprd_spi_read_bufs_u32(struct sprd_spi * ss,u32 len)390 static 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
sprd_spi_txrx_bufs(struct spi_device * sdev,struct spi_transfer * t)402 static 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;
451 complete:
452 sprd_spi_enter_idle(ss);
453
454 return ret;
455 }
456
sprd_spi_irq_enable(struct sprd_spi * ss)457 static 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
sprd_spi_irq_disable(struct sprd_spi * ss)471 static void sprd_spi_irq_disable(struct sprd_spi *ss)
472 {
473 writel_relaxed(0, ss->base + SPRD_SPI_INT_EN);
474 }
475
sprd_spi_dma_enable(struct sprd_spi * ss,bool enable)476 static 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
sprd_spi_dma_submit(struct dma_chan * dma_chan,struct dma_slave_config * c,struct sg_table * sg,enum dma_transfer_direction dir)488 static 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
sprd_spi_dma_rx_config(struct sprd_spi * ss,struct spi_transfer * t)517 static 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
sprd_spi_dma_tx_config(struct sprd_spi * ss,struct spi_transfer * t)535 static 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
sprd_spi_dma_request(struct sprd_spi * ss)553 static 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 if (PTR_ERR(ss->dma.dma_chan[SPRD_SPI_RX]) == -EPROBE_DEFER)
558 return PTR_ERR(ss->dma.dma_chan[SPRD_SPI_RX]);
559
560 dev_err(ss->dev, "request RX DMA channel failed!\n");
561 return PTR_ERR(ss->dma.dma_chan[SPRD_SPI_RX]);
562 }
563
564 ss->dma.dma_chan[SPRD_SPI_TX] = dma_request_chan(ss->dev, "tx_chn");
565 if (IS_ERR_OR_NULL(ss->dma.dma_chan[SPRD_SPI_TX])) {
566 if (PTR_ERR(ss->dma.dma_chan[SPRD_SPI_TX]) == -EPROBE_DEFER)
567 return PTR_ERR(ss->dma.dma_chan[SPRD_SPI_TX]);
568
569 dev_err(ss->dev, "request TX DMA channel failed!\n");
570 dma_release_channel(ss->dma.dma_chan[SPRD_SPI_RX]);
571 return PTR_ERR(ss->dma.dma_chan[SPRD_SPI_TX]);
572 }
573
574 return 0;
575 }
576
sprd_spi_dma_release(struct sprd_spi * ss)577 static void sprd_spi_dma_release(struct sprd_spi *ss)
578 {
579 if (ss->dma.dma_chan[SPRD_SPI_RX])
580 dma_release_channel(ss->dma.dma_chan[SPRD_SPI_RX]);
581
582 if (ss->dma.dma_chan[SPRD_SPI_TX])
583 dma_release_channel(ss->dma.dma_chan[SPRD_SPI_TX]);
584 }
585
sprd_spi_dma_txrx_bufs(struct spi_device * sdev,struct spi_transfer * t)586 static int sprd_spi_dma_txrx_bufs(struct spi_device *sdev,
587 struct spi_transfer *t)
588 {
589 struct sprd_spi *ss = spi_master_get_devdata(sdev->master);
590 u32 trans_len = ss->trans_len;
591 int ret, write_size = 0;
592
593 reinit_completion(&ss->xfer_completion);
594 sprd_spi_irq_enable(ss);
595 if (ss->trans_mode & SPRD_SPI_TX_MODE) {
596 write_size = sprd_spi_dma_tx_config(ss, t);
597 sprd_spi_set_tx_length(ss, trans_len);
598
599 /*
600 * For our 3 wires mode or dual TX line mode, we need
601 * to request the controller to transfer.
602 */
603 if (ss->hw_mode & SPI_3WIRE || ss->hw_mode & SPI_TX_DUAL)
604 sprd_spi_tx_req(ss);
605 } else {
606 sprd_spi_set_rx_length(ss, trans_len);
607
608 /*
609 * For our 3 wires mode or dual TX line mode, we need
610 * to request the controller to read.
611 */
612 if (ss->hw_mode & SPI_3WIRE || ss->hw_mode & SPI_TX_DUAL)
613 sprd_spi_rx_req(ss);
614 else
615 write_size = ss->write_bufs(ss, trans_len);
616 }
617
618 if (write_size < 0) {
619 ret = write_size;
620 dev_err(ss->dev, "failed to write, ret = %d\n", ret);
621 goto trans_complete;
622 }
623
624 if (ss->trans_mode & SPRD_SPI_RX_MODE) {
625 /*
626 * Set up the DMA receive data length, which must be an
627 * integral multiple of fragment length. But when the length
628 * of received data is less than fragment length, DMA can be
629 * configured to receive data according to the actual length
630 * of received data.
631 */
632 ss->dma.rx_len = t->len > ss->dma.fragmens_len ?
633 (t->len - t->len % ss->dma.fragmens_len) :
634 t->len;
635 ret = sprd_spi_dma_rx_config(ss, t);
636 if (ret < 0) {
637 dev_err(&sdev->dev,
638 "failed to configure rx DMA, ret = %d\n", ret);
639 goto trans_complete;
640 }
641 }
642
643 sprd_spi_dma_enable(ss, true);
644 wait_for_completion(&(ss->xfer_completion));
645
646 if (ss->trans_mode & SPRD_SPI_TX_MODE)
647 ret = write_size;
648 else
649 ret = ss->dma.rx_len;
650
651 trans_complete:
652 sprd_spi_dma_enable(ss, false);
653 sprd_spi_enter_idle(ss);
654 sprd_spi_irq_disable(ss);
655
656 return ret;
657 }
658
sprd_spi_set_speed(struct sprd_spi * ss,u32 speed_hz)659 static void sprd_spi_set_speed(struct sprd_spi *ss, u32 speed_hz)
660 {
661 /*
662 * From SPI datasheet, the prescale calculation formula:
663 * prescale = SPI source clock / (2 * SPI_freq) - 1;
664 */
665 u32 clk_div = DIV_ROUND_UP(ss->src_clk, speed_hz << 1) - 1;
666
667 /* Save the real hardware speed */
668 ss->hw_speed_hz = (ss->src_clk >> 1) / (clk_div + 1);
669 writel_relaxed(clk_div, ss->base + SPRD_SPI_CLKD);
670 }
671
sprd_spi_init_hw(struct sprd_spi * ss,struct spi_transfer * t)672 static void sprd_spi_init_hw(struct sprd_spi *ss, struct spi_transfer *t)
673 {
674 u16 word_delay, interval;
675 u32 val;
676
677 val = readl_relaxed(ss->base + SPRD_SPI_CTL0);
678 val &= ~(SPRD_SPI_SCK_REV | SPRD_SPI_NG_TX | SPRD_SPI_NG_RX);
679 /* Set default chip selection, clock phase and clock polarity */
680 val |= ss->hw_mode & SPI_CPHA ? SPRD_SPI_NG_RX : SPRD_SPI_NG_TX;
681 val |= ss->hw_mode & SPI_CPOL ? SPRD_SPI_SCK_REV : 0;
682 writel_relaxed(val, ss->base + SPRD_SPI_CTL0);
683
684 /*
685 * Set the intervals of two SPI frames, and the inteval calculation
686 * formula as below per datasheet:
687 * interval time (source clock cycles) = interval * 4 + 10.
688 */
689 word_delay = clamp_t(u16, t->word_delay, SPRD_SPI_MIN_DELAY_CYCLE,
690 SPRD_SPI_MAX_DELAY_CYCLE);
691 interval = DIV_ROUND_UP(word_delay - 10, 4);
692 ss->word_delay = interval * 4 + 10;
693 writel_relaxed(interval, ss->base + SPRD_SPI_CTL5);
694
695 /* Reset SPI fifo */
696 writel_relaxed(1, ss->base + SPRD_SPI_FIFO_RST);
697 writel_relaxed(0, ss->base + SPRD_SPI_FIFO_RST);
698
699 /* Set SPI work mode */
700 val = readl_relaxed(ss->base + SPRD_SPI_CTL7);
701 val &= ~SPRD_SPI_MODE_MASK;
702
703 if (ss->hw_mode & SPI_3WIRE)
704 val |= SPRD_SPI_3WIRE_MODE << SPRD_SPI_MODE_OFFSET;
705 else
706 val |= SPRD_SPI_4WIRE_MODE << SPRD_SPI_MODE_OFFSET;
707
708 if (ss->hw_mode & SPI_TX_DUAL)
709 val |= SPRD_SPI_DATA_LINE2_EN;
710 else
711 val &= ~SPRD_SPI_DATA_LINE2_EN;
712
713 writel_relaxed(val, ss->base + SPRD_SPI_CTL7);
714 }
715
sprd_spi_setup_transfer(struct spi_device * sdev,struct spi_transfer * t)716 static int sprd_spi_setup_transfer(struct spi_device *sdev,
717 struct spi_transfer *t)
718 {
719 struct sprd_spi *ss = spi_controller_get_devdata(sdev->controller);
720 u8 bits_per_word = t->bits_per_word;
721 u32 val, mode = 0;
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 sprd_spi_init_hw(ss, t);
729
730 /* Set tansfer speed and valid bits */
731 sprd_spi_set_speed(ss, t->speed_hz);
732 sprd_spi_set_transfer_bits(ss, bits_per_word);
733
734 if (bits_per_word > 16)
735 bits_per_word = round_up(bits_per_word, 16);
736 else
737 bits_per_word = round_up(bits_per_word, 8);
738
739 switch (bits_per_word) {
740 case 8:
741 ss->trans_len = t->len;
742 ss->read_bufs = sprd_spi_read_bufs_u8;
743 ss->write_bufs = sprd_spi_write_bufs_u8;
744 ss->dma.width = DMA_SLAVE_BUSWIDTH_1_BYTE;
745 ss->dma.fragmens_len = SPRD_SPI_DMA_STEP;
746 break;
747 case 16:
748 ss->trans_len = t->len >> 1;
749 ss->read_bufs = sprd_spi_read_bufs_u16;
750 ss->write_bufs = sprd_spi_write_bufs_u16;
751 ss->dma.width = DMA_SLAVE_BUSWIDTH_2_BYTES;
752 ss->dma.fragmens_len = SPRD_SPI_DMA_STEP << 1;
753 break;
754 case 32:
755 ss->trans_len = t->len >> 2;
756 ss->read_bufs = sprd_spi_read_bufs_u32;
757 ss->write_bufs = sprd_spi_write_bufs_u32;
758 ss->dma.width = DMA_SLAVE_BUSWIDTH_4_BYTES;
759 ss->dma.fragmens_len = SPRD_SPI_DMA_STEP << 2;
760 break;
761 default:
762 return -EINVAL;
763 }
764
765 /* Set transfer read or write mode */
766 val = readl_relaxed(ss->base + SPRD_SPI_CTL1);
767 val &= ~SPRD_SPI_RTX_MD_MASK;
768 if (t->tx_buf)
769 mode |= SPRD_SPI_TX_MODE;
770 if (t->rx_buf)
771 mode |= SPRD_SPI_RX_MODE;
772
773 writel_relaxed(val | mode, ss->base + SPRD_SPI_CTL1);
774
775 ss->trans_mode = mode;
776
777 /*
778 * If in only receive mode, we need to trigger the SPI controller to
779 * receive data automatically.
780 */
781 if (ss->trans_mode == SPRD_SPI_RX_MODE)
782 ss->write_bufs = sprd_spi_write_only_receive;
783
784 return 0;
785 }
786
sprd_spi_transfer_one(struct spi_controller * sctlr,struct spi_device * sdev,struct spi_transfer * t)787 static int sprd_spi_transfer_one(struct spi_controller *sctlr,
788 struct spi_device *sdev,
789 struct spi_transfer *t)
790 {
791 int ret;
792
793 ret = sprd_spi_setup_transfer(sdev, t);
794 if (ret)
795 goto setup_err;
796
797 if (sctlr->can_dma(sctlr, sdev, t))
798 ret = sprd_spi_dma_txrx_bufs(sdev, t);
799 else
800 ret = sprd_spi_txrx_bufs(sdev, t);
801
802 if (ret == t->len)
803 ret = 0;
804 else if (ret >= 0)
805 ret = -EREMOTEIO;
806
807 setup_err:
808 spi_finalize_current_transfer(sctlr);
809
810 return ret;
811 }
812
sprd_spi_handle_irq(int irq,void * data)813 static irqreturn_t sprd_spi_handle_irq(int irq, void *data)
814 {
815 struct sprd_spi *ss = (struct sprd_spi *)data;
816 u32 val = readl_relaxed(ss->base + SPRD_SPI_INT_MASK_STS);
817
818 if (val & SPRD_SPI_MASK_TX_END) {
819 writel_relaxed(SPRD_SPI_TX_END_CLR, ss->base + SPRD_SPI_INT_CLR);
820 if (!(ss->trans_mode & SPRD_SPI_RX_MODE))
821 complete(&ss->xfer_completion);
822
823 return IRQ_HANDLED;
824 }
825
826 if (val & SPRD_SPI_MASK_RX_END) {
827 writel_relaxed(SPRD_SPI_RX_END_CLR, ss->base + SPRD_SPI_INT_CLR);
828 if (ss->dma.rx_len < ss->len) {
829 ss->rx_buf += ss->dma.rx_len;
830 ss->dma.rx_len +=
831 ss->read_bufs(ss, ss->len - ss->dma.rx_len);
832 }
833 complete(&ss->xfer_completion);
834
835 return IRQ_HANDLED;
836 }
837
838 return IRQ_NONE;
839 }
840
sprd_spi_irq_init(struct platform_device * pdev,struct sprd_spi * ss)841 static int sprd_spi_irq_init(struct platform_device *pdev, struct sprd_spi *ss)
842 {
843 int ret;
844
845 ss->irq = platform_get_irq(pdev, 0);
846 if (ss->irq < 0)
847 return ss->irq;
848
849 ret = devm_request_irq(&pdev->dev, ss->irq, sprd_spi_handle_irq,
850 0, pdev->name, ss);
851 if (ret)
852 dev_err(&pdev->dev, "failed to request spi irq %d, ret = %d\n",
853 ss->irq, ret);
854
855 return ret;
856 }
857
sprd_spi_clk_init(struct platform_device * pdev,struct sprd_spi * ss)858 static int sprd_spi_clk_init(struct platform_device *pdev, struct sprd_spi *ss)
859 {
860 struct clk *clk_spi, *clk_parent;
861
862 clk_spi = devm_clk_get(&pdev->dev, "spi");
863 if (IS_ERR(clk_spi)) {
864 dev_warn(&pdev->dev, "can't get the spi clock\n");
865 clk_spi = NULL;
866 }
867
868 clk_parent = devm_clk_get(&pdev->dev, "source");
869 if (IS_ERR(clk_parent)) {
870 dev_warn(&pdev->dev, "can't get the source clock\n");
871 clk_parent = NULL;
872 }
873
874 ss->clk = devm_clk_get(&pdev->dev, "enable");
875 if (IS_ERR(ss->clk)) {
876 dev_err(&pdev->dev, "can't get the enable clock\n");
877 return PTR_ERR(ss->clk);
878 }
879
880 if (!clk_set_parent(clk_spi, clk_parent))
881 ss->src_clk = clk_get_rate(clk_spi);
882 else
883 ss->src_clk = SPRD_SPI_DEFAULT_SOURCE;
884
885 return 0;
886 }
887
sprd_spi_can_dma(struct spi_controller * sctlr,struct spi_device * spi,struct spi_transfer * t)888 static bool sprd_spi_can_dma(struct spi_controller *sctlr,
889 struct spi_device *spi, struct spi_transfer *t)
890 {
891 struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
892
893 return ss->dma.enable && (t->len > SPRD_SPI_FIFO_SIZE);
894 }
895
sprd_spi_dma_init(struct platform_device * pdev,struct sprd_spi * ss)896 static int sprd_spi_dma_init(struct platform_device *pdev, struct sprd_spi *ss)
897 {
898 int ret;
899
900 ret = sprd_spi_dma_request(ss);
901 if (ret) {
902 if (ret == -EPROBE_DEFER)
903 return ret;
904
905 dev_warn(&pdev->dev,
906 "failed to request dma, enter no dma mode, ret = %d\n",
907 ret);
908
909 return 0;
910 }
911
912 ss->dma.enable = true;
913
914 return 0;
915 }
916
sprd_spi_probe(struct platform_device * pdev)917 static int sprd_spi_probe(struct platform_device *pdev)
918 {
919 struct spi_controller *sctlr;
920 struct resource *res;
921 struct sprd_spi *ss;
922 int ret;
923
924 pdev->id = of_alias_get_id(pdev->dev.of_node, "spi");
925 sctlr = spi_alloc_master(&pdev->dev, sizeof(*ss));
926 if (!sctlr)
927 return -ENOMEM;
928
929 ss = spi_controller_get_devdata(sctlr);
930 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
931 ss->base = devm_ioremap_resource(&pdev->dev, 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
990 err_rpm_put:
991 pm_runtime_put_noidle(&pdev->dev);
992 pm_runtime_disable(&pdev->dev);
993 disable_clk:
994 clk_disable_unprepare(ss->clk);
995 release_dma:
996 sprd_spi_dma_release(ss);
997 free_controller:
998 spi_controller_put(sctlr);
999
1000 return ret;
1001 }
1002
sprd_spi_remove(struct platform_device * pdev)1003 static int 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 return ret;
1013 }
1014
1015 spi_controller_suspend(sctlr);
1016
1017 if (ss->dma.enable)
1018 sprd_spi_dma_release(ss);
1019 clk_disable_unprepare(ss->clk);
1020 pm_runtime_put_noidle(&pdev->dev);
1021 pm_runtime_disable(&pdev->dev);
1022
1023 return 0;
1024 }
1025
sprd_spi_runtime_suspend(struct device * dev)1026 static int __maybe_unused sprd_spi_runtime_suspend(struct device *dev)
1027 {
1028 struct spi_controller *sctlr = dev_get_drvdata(dev);
1029 struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
1030
1031 if (ss->dma.enable)
1032 sprd_spi_dma_release(ss);
1033
1034 clk_disable_unprepare(ss->clk);
1035
1036 return 0;
1037 }
1038
sprd_spi_runtime_resume(struct device * dev)1039 static int __maybe_unused sprd_spi_runtime_resume(struct device *dev)
1040 {
1041 struct spi_controller *sctlr = dev_get_drvdata(dev);
1042 struct sprd_spi *ss = spi_controller_get_devdata(sctlr);
1043 int ret;
1044
1045 ret = clk_prepare_enable(ss->clk);
1046 if (ret)
1047 return ret;
1048
1049 if (!ss->dma.enable)
1050 return 0;
1051
1052 ret = sprd_spi_dma_request(ss);
1053 if (ret)
1054 clk_disable_unprepare(ss->clk);
1055
1056 return ret;
1057 }
1058
1059 static const struct dev_pm_ops sprd_spi_pm_ops = {
1060 SET_RUNTIME_PM_OPS(sprd_spi_runtime_suspend,
1061 sprd_spi_runtime_resume, NULL)
1062 };
1063
1064 static const struct of_device_id sprd_spi_of_match[] = {
1065 { .compatible = "sprd,sc9860-spi", },
1066 { /* sentinel */ }
1067 };
1068
1069 static struct platform_driver sprd_spi_driver = {
1070 .driver = {
1071 .name = "sprd-spi",
1072 .of_match_table = sprd_spi_of_match,
1073 .pm = &sprd_spi_pm_ops,
1074 },
1075 .probe = sprd_spi_probe,
1076 .remove = sprd_spi_remove,
1077 };
1078
1079 module_platform_driver(sprd_spi_driver);
1080
1081 MODULE_DESCRIPTION("Spreadtrum SPI Controller driver");
1082 MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
1083 MODULE_LICENSE("GPL v2");
1084