1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
4 * Author: Addy Ke <addy.ke@rock-chips.com>
5 */
6
7 #include <linux/clk.h>
8 #include <linux/dmaengine.h>
9 #include <linux/interrupt.h>
10 #include <linux/module.h>
11 #include <linux/of.h>
12 #include <linux/pinctrl/consumer.h>
13 #include <linux/platform_device.h>
14 #include <linux/spi/spi.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/scatterlist.h>
17
18 #define DRIVER_NAME "rockchip-spi"
19
20 #define ROCKCHIP_SPI_CLR_BITS(reg, bits) \
21 writel_relaxed(readl_relaxed(reg) & ~(bits), reg)
22 #define ROCKCHIP_SPI_SET_BITS(reg, bits) \
23 writel_relaxed(readl_relaxed(reg) | (bits), reg)
24
25 /* SPI register offsets */
26 #define ROCKCHIP_SPI_CTRLR0 0x0000
27 #define ROCKCHIP_SPI_CTRLR1 0x0004
28 #define ROCKCHIP_SPI_SSIENR 0x0008
29 #define ROCKCHIP_SPI_SER 0x000c
30 #define ROCKCHIP_SPI_BAUDR 0x0010
31 #define ROCKCHIP_SPI_TXFTLR 0x0014
32 #define ROCKCHIP_SPI_RXFTLR 0x0018
33 #define ROCKCHIP_SPI_TXFLR 0x001c
34 #define ROCKCHIP_SPI_RXFLR 0x0020
35 #define ROCKCHIP_SPI_SR 0x0024
36 #define ROCKCHIP_SPI_IPR 0x0028
37 #define ROCKCHIP_SPI_IMR 0x002c
38 #define ROCKCHIP_SPI_ISR 0x0030
39 #define ROCKCHIP_SPI_RISR 0x0034
40 #define ROCKCHIP_SPI_ICR 0x0038
41 #define ROCKCHIP_SPI_DMACR 0x003c
42 #define ROCKCHIP_SPI_DMATDLR 0x0040
43 #define ROCKCHIP_SPI_DMARDLR 0x0044
44 #define ROCKCHIP_SPI_VERSION 0x0048
45 #define ROCKCHIP_SPI_TXDR 0x0400
46 #define ROCKCHIP_SPI_RXDR 0x0800
47
48 /* Bit fields in CTRLR0 */
49 #define CR0_DFS_OFFSET 0
50 #define CR0_DFS_4BIT 0x0
51 #define CR0_DFS_8BIT 0x1
52 #define CR0_DFS_16BIT 0x2
53
54 #define CR0_CFS_OFFSET 2
55
56 #define CR0_SCPH_OFFSET 6
57
58 #define CR0_SCPOL_OFFSET 7
59
60 #define CR0_CSM_OFFSET 8
61 #define CR0_CSM_KEEP 0x0
62 /* ss_n be high for half sclk_out cycles */
63 #define CR0_CSM_HALF 0X1
64 /* ss_n be high for one sclk_out cycle */
65 #define CR0_CSM_ONE 0x2
66
67 /* ss_n to sclk_out delay */
68 #define CR0_SSD_OFFSET 10
69 /*
70 * The period between ss_n active and
71 * sclk_out active is half sclk_out cycles
72 */
73 #define CR0_SSD_HALF 0x0
74 /*
75 * The period between ss_n active and
76 * sclk_out active is one sclk_out cycle
77 */
78 #define CR0_SSD_ONE 0x1
79
80 #define CR0_EM_OFFSET 11
81 #define CR0_EM_LITTLE 0x0
82 #define CR0_EM_BIG 0x1
83
84 #define CR0_FBM_OFFSET 12
85 #define CR0_FBM_MSB 0x0
86 #define CR0_FBM_LSB 0x1
87
88 #define CR0_BHT_OFFSET 13
89 #define CR0_BHT_16BIT 0x0
90 #define CR0_BHT_8BIT 0x1
91
92 #define CR0_RSD_OFFSET 14
93 #define CR0_RSD_MAX 0x3
94
95 #define CR0_FRF_OFFSET 16
96 #define CR0_FRF_SPI 0x0
97 #define CR0_FRF_SSP 0x1
98 #define CR0_FRF_MICROWIRE 0x2
99
100 #define CR0_XFM_OFFSET 18
101 #define CR0_XFM_MASK (0x03 << SPI_XFM_OFFSET)
102 #define CR0_XFM_TR 0x0
103 #define CR0_XFM_TO 0x1
104 #define CR0_XFM_RO 0x2
105
106 #define CR0_OPM_OFFSET 20
107 #define CR0_OPM_HOST 0x0
108 #define CR0_OPM_TARGET 0x1
109
110 #define CR0_SOI_OFFSET 23
111
112 #define CR0_MTM_OFFSET 0x21
113
114 /* Bit fields in SER, 2bit */
115 #define SER_MASK 0x3
116
117 /* Bit fields in BAUDR */
118 #define BAUDR_SCKDV_MIN 2
119 #define BAUDR_SCKDV_MAX 65534
120
121 /* Bit fields in SR, 6bit */
122 #define SR_MASK 0x3f
123 #define SR_BUSY (1 << 0)
124 #define SR_TF_FULL (1 << 1)
125 #define SR_TF_EMPTY (1 << 2)
126 #define SR_RF_EMPTY (1 << 3)
127 #define SR_RF_FULL (1 << 4)
128 #define SR_TARGET_TX_BUSY (1 << 5)
129
130 /* Bit fields in ISR, IMR, ISR, RISR, 5bit */
131 #define INT_MASK 0x1f
132 #define INT_TF_EMPTY (1 << 0)
133 #define INT_TF_OVERFLOW (1 << 1)
134 #define INT_RF_UNDERFLOW (1 << 2)
135 #define INT_RF_OVERFLOW (1 << 3)
136 #define INT_RF_FULL (1 << 4)
137 #define INT_CS_INACTIVE (1 << 6)
138
139 /* Bit fields in ICR, 4bit */
140 #define ICR_MASK 0x0f
141 #define ICR_ALL (1 << 0)
142 #define ICR_RF_UNDERFLOW (1 << 1)
143 #define ICR_RF_OVERFLOW (1 << 2)
144 #define ICR_TF_OVERFLOW (1 << 3)
145
146 /* Bit fields in DMACR */
147 #define RF_DMA_EN (1 << 0)
148 #define TF_DMA_EN (1 << 1)
149
150 /* Driver state flags */
151 #define RXDMA (1 << 0)
152 #define TXDMA (1 << 1)
153
154 /* sclk_out: spi host internal logic in rk3x can support 50Mhz */
155 #define MAX_SCLK_OUT 50000000U
156
157 /*
158 * SPI_CTRLR1 is 16-bits, so we should support lengths of 0xffff + 1. However,
159 * the controller seems to hang when given 0x10000, so stick with this for now.
160 */
161 #define ROCKCHIP_SPI_MAX_TRANLEN 0xffff
162
163 #define ROCKCHIP_SPI_MAX_NATIVE_CS_NUM 2
164 #define ROCKCHIP_SPI_VER2_TYPE1 0x05EC0002
165 #define ROCKCHIP_SPI_VER2_TYPE2 0x00110002
166
167 #define ROCKCHIP_AUTOSUSPEND_TIMEOUT 2000
168
169 struct rockchip_spi {
170 struct device *dev;
171
172 struct clk *spiclk;
173 struct clk *apb_pclk;
174
175 void __iomem *regs;
176 dma_addr_t dma_addr_rx;
177 dma_addr_t dma_addr_tx;
178
179 const void *tx;
180 void *rx;
181 unsigned int tx_left;
182 unsigned int rx_left;
183
184 atomic_t state;
185
186 /*depth of the FIFO buffer */
187 u32 fifo_len;
188 /* frequency of spiclk */
189 u32 freq;
190
191 u8 n_bytes;
192 u8 rsd;
193
194 bool target_abort;
195 bool cs_inactive; /* spi target tansmition stop when cs inactive */
196 bool cs_high_supported; /* native CS supports active-high polarity */
197
198 struct spi_transfer *xfer; /* Store xfer temporarily */
199 };
200
spi_enable_chip(struct rockchip_spi * rs,bool enable)201 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
202 {
203 writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
204 }
205
wait_for_tx_idle(struct rockchip_spi * rs,bool target_mode)206 static inline void wait_for_tx_idle(struct rockchip_spi *rs, bool target_mode)
207 {
208 unsigned long timeout = jiffies + msecs_to_jiffies(5);
209
210 do {
211 if (target_mode) {
212 if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_TARGET_TX_BUSY) &&
213 !((readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY)))
214 return;
215 } else {
216 if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
217 return;
218 }
219 } while (!time_after(jiffies, timeout));
220
221 dev_warn(rs->dev, "spi controller is in busy state!\n");
222 }
223
get_fifo_len(struct rockchip_spi * rs)224 static u32 get_fifo_len(struct rockchip_spi *rs)
225 {
226 u32 ver;
227
228 ver = readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION);
229
230 switch (ver) {
231 case ROCKCHIP_SPI_VER2_TYPE1:
232 case ROCKCHIP_SPI_VER2_TYPE2:
233 return 64;
234 default:
235 return 32;
236 }
237 }
238
rockchip_spi_set_cs(struct spi_device * spi,bool enable)239 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
240 {
241 struct spi_controller *ctlr = spi->controller;
242 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
243 bool cs_asserted = spi->mode & SPI_CS_HIGH ? enable : !enable;
244
245 if (cs_asserted) {
246 /* Keep things powered as long as CS is asserted */
247 pm_runtime_get_sync(rs->dev);
248
249 if (spi_get_csgpiod(spi, 0))
250 ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
251 else
252 ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
253 BIT(spi_get_chipselect(spi, 0)));
254 } else {
255 if (spi_get_csgpiod(spi, 0))
256 ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
257 else
258 ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
259 BIT(spi_get_chipselect(spi, 0)));
260
261 /* Drop reference from when we first asserted CS */
262 pm_runtime_put(rs->dev);
263 }
264 }
265
rockchip_spi_handle_err(struct spi_controller * ctlr,struct spi_message * msg)266 static void rockchip_spi_handle_err(struct spi_controller *ctlr,
267 struct spi_message *msg)
268 {
269 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
270
271 /* stop running spi transfer
272 * this also flushes both rx and tx fifos
273 */
274 spi_enable_chip(rs, false);
275
276 /* make sure all interrupts are masked and status cleared */
277 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
278 writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
279
280 if (atomic_read(&rs->state) & TXDMA)
281 dmaengine_terminate_async(ctlr->dma_tx);
282
283 if (atomic_read(&rs->state) & RXDMA)
284 dmaengine_terminate_async(ctlr->dma_rx);
285 }
286
rockchip_spi_pio_writer(struct rockchip_spi * rs)287 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
288 {
289 u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
290 u32 words = min(rs->tx_left, tx_free);
291
292 rs->tx_left -= words;
293 for (; words; words--) {
294 u32 txw;
295
296 if (rs->n_bytes == 1)
297 txw = *(u8 *)rs->tx;
298 else
299 txw = *(u16 *)rs->tx;
300
301 writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
302 rs->tx += rs->n_bytes;
303 }
304 }
305
rockchip_spi_pio_reader(struct rockchip_spi * rs)306 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
307 {
308 u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
309 u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
310
311 /* the hardware doesn't allow us to change fifo threshold
312 * level while spi is enabled, so instead make sure to leave
313 * enough words in the rx fifo to get the last interrupt
314 * exactly when all words have been received
315 */
316 if (rx_left) {
317 u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
318
319 if (rx_left < ftl) {
320 rx_left = ftl;
321 words = rs->rx_left - rx_left;
322 }
323 }
324
325 rs->rx_left = rx_left;
326 for (; words; words--) {
327 u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
328
329 if (!rs->rx)
330 continue;
331
332 if (rs->n_bytes == 1)
333 *(u8 *)rs->rx = (u8)rxw;
334 else
335 *(u16 *)rs->rx = (u16)rxw;
336 rs->rx += rs->n_bytes;
337 }
338 }
339
rockchip_spi_isr(int irq,void * dev_id)340 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
341 {
342 struct spi_controller *ctlr = dev_id;
343 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
344
345 /* When int_cs_inactive comes, spi target abort */
346 if (rs->cs_inactive && readl_relaxed(rs->regs + ROCKCHIP_SPI_IMR) & INT_CS_INACTIVE) {
347 ctlr->target_abort(ctlr);
348 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
349 writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
350
351 return IRQ_HANDLED;
352 }
353
354 if (rs->tx_left)
355 rockchip_spi_pio_writer(rs);
356
357 rockchip_spi_pio_reader(rs);
358 if (!rs->rx_left) {
359 spi_enable_chip(rs, false);
360 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
361 writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
362 spi_finalize_current_transfer(ctlr);
363 }
364
365 return IRQ_HANDLED;
366 }
367
rockchip_spi_prepare_irq(struct rockchip_spi * rs,struct spi_controller * ctlr,struct spi_transfer * xfer)368 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
369 struct spi_controller *ctlr,
370 struct spi_transfer *xfer)
371 {
372 rs->tx = xfer->tx_buf;
373 rs->rx = xfer->rx_buf;
374 rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
375 rs->rx_left = xfer->len / rs->n_bytes;
376
377 writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
378
379 spi_enable_chip(rs, true);
380
381 if (rs->tx_left)
382 rockchip_spi_pio_writer(rs);
383
384 if (rs->cs_inactive)
385 writel_relaxed(INT_RF_FULL | INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
386 else
387 writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
388
389 /* 1 means the transfer is in progress */
390 return 1;
391 }
392
rockchip_spi_dma_rxcb(void * data)393 static void rockchip_spi_dma_rxcb(void *data)
394 {
395 struct spi_controller *ctlr = data;
396 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
397 int state = atomic_fetch_andnot(RXDMA, &rs->state);
398
399 if (state & TXDMA && !rs->target_abort)
400 return;
401
402 if (rs->cs_inactive)
403 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
404
405 spi_enable_chip(rs, false);
406 spi_finalize_current_transfer(ctlr);
407 }
408
rockchip_spi_dma_txcb(void * data)409 static void rockchip_spi_dma_txcb(void *data)
410 {
411 struct spi_controller *ctlr = data;
412 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
413 int state = atomic_fetch_andnot(TXDMA, &rs->state);
414
415 if (state & RXDMA && !rs->target_abort)
416 return;
417
418 /* Wait until the FIFO data completely. */
419 wait_for_tx_idle(rs, ctlr->target);
420
421 spi_enable_chip(rs, false);
422 spi_finalize_current_transfer(ctlr);
423 }
424
rockchip_spi_calc_burst_size(u32 data_len)425 static u32 rockchip_spi_calc_burst_size(u32 data_len)
426 {
427 u32 i;
428
429 /* burst size: 1, 2, 4, 8 */
430 for (i = 1; i < 8; i <<= 1) {
431 if (data_len & i)
432 break;
433 }
434
435 return i;
436 }
437
rockchip_spi_prepare_dma(struct rockchip_spi * rs,struct spi_controller * ctlr,struct spi_transfer * xfer)438 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
439 struct spi_controller *ctlr, struct spi_transfer *xfer)
440 {
441 struct dma_async_tx_descriptor *rxdesc, *txdesc;
442
443 atomic_set(&rs->state, 0);
444
445 rs->tx = xfer->tx_buf;
446 rs->rx = xfer->rx_buf;
447
448 rxdesc = NULL;
449 if (xfer->rx_buf) {
450 struct dma_slave_config rxconf = {
451 .direction = DMA_DEV_TO_MEM,
452 .src_addr = rs->dma_addr_rx,
453 .src_addr_width = rs->n_bytes,
454 .src_maxburst = rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes),
455 };
456
457 dmaengine_slave_config(ctlr->dma_rx, &rxconf);
458
459 rxdesc = dmaengine_prep_slave_sg(
460 ctlr->dma_rx,
461 xfer->rx_sg.sgl, xfer->rx_sg.nents,
462 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
463 if (!rxdesc)
464 return -EINVAL;
465
466 rxdesc->callback = rockchip_spi_dma_rxcb;
467 rxdesc->callback_param = ctlr;
468 }
469
470 txdesc = NULL;
471 if (xfer->tx_buf) {
472 struct dma_slave_config txconf = {
473 .direction = DMA_MEM_TO_DEV,
474 .dst_addr = rs->dma_addr_tx,
475 .dst_addr_width = rs->n_bytes,
476 .dst_maxburst = rs->fifo_len / 4,
477 };
478
479 dmaengine_slave_config(ctlr->dma_tx, &txconf);
480
481 txdesc = dmaengine_prep_slave_sg(
482 ctlr->dma_tx,
483 xfer->tx_sg.sgl, xfer->tx_sg.nents,
484 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
485 if (!txdesc) {
486 if (rxdesc)
487 dmaengine_terminate_sync(ctlr->dma_rx);
488 return -EINVAL;
489 }
490
491 txdesc->callback = rockchip_spi_dma_txcb;
492 txdesc->callback_param = ctlr;
493 }
494
495 /* rx must be started before tx due to spi instinct */
496 if (rxdesc) {
497 atomic_or(RXDMA, &rs->state);
498 ctlr->dma_rx->cookie = dmaengine_submit(rxdesc);
499 dma_async_issue_pending(ctlr->dma_rx);
500 }
501
502 if (rs->cs_inactive)
503 writel_relaxed(INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
504
505 spi_enable_chip(rs, true);
506
507 if (txdesc) {
508 atomic_or(TXDMA, &rs->state);
509 dmaengine_submit(txdesc);
510 dma_async_issue_pending(ctlr->dma_tx);
511 }
512
513 /* 1 means the transfer is in progress */
514 return 1;
515 }
516
rockchip_spi_config(struct rockchip_spi * rs,struct spi_device * spi,struct spi_transfer * xfer,bool use_dma,bool target_mode)517 static int rockchip_spi_config(struct rockchip_spi *rs,
518 struct spi_device *spi, struct spi_transfer *xfer,
519 bool use_dma, bool target_mode)
520 {
521 u32 cr0 = CR0_FRF_SPI << CR0_FRF_OFFSET
522 | CR0_BHT_8BIT << CR0_BHT_OFFSET
523 | CR0_SSD_ONE << CR0_SSD_OFFSET
524 | CR0_EM_BIG << CR0_EM_OFFSET;
525 u32 cr1;
526 u32 dmacr = 0;
527
528 if (target_mode)
529 cr0 |= CR0_OPM_TARGET << CR0_OPM_OFFSET;
530 rs->target_abort = false;
531
532 cr0 |= rs->rsd << CR0_RSD_OFFSET;
533 cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
534 if (spi->mode & SPI_LSB_FIRST)
535 cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
536 if (spi->mode & SPI_CS_HIGH)
537 cr0 |= BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET;
538
539 if (xfer->rx_buf && xfer->tx_buf)
540 cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
541 else if (xfer->rx_buf)
542 cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
543 else if (use_dma)
544 cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
545
546 switch (xfer->bits_per_word) {
547 case 4:
548 cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
549 cr1 = xfer->len - 1;
550 break;
551 case 8:
552 cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
553 cr1 = xfer->len - 1;
554 break;
555 case 16:
556 cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
557 cr1 = xfer->len / 2 - 1;
558 break;
559 default:
560 /* we only whitelist 4, 8 and 16 bit words in
561 * ctlr->bits_per_word_mask, so this shouldn't
562 * happen
563 */
564 dev_err(rs->dev, "unknown bits per word: %d\n",
565 xfer->bits_per_word);
566 return -EINVAL;
567 }
568
569 if (use_dma) {
570 if (xfer->tx_buf)
571 dmacr |= TF_DMA_EN;
572 if (xfer->rx_buf)
573 dmacr |= RF_DMA_EN;
574 }
575
576 writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
577 writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
578
579 /* unfortunately setting the fifo threshold level to generate an
580 * interrupt exactly when the fifo is full doesn't seem to work,
581 * so we need the strict inequality here
582 */
583 if ((xfer->len / rs->n_bytes) < rs->fifo_len)
584 writel_relaxed(xfer->len / rs->n_bytes - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
585 else
586 writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
587
588 writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
589 writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,
590 rs->regs + ROCKCHIP_SPI_DMARDLR);
591 writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
592
593 /* the hardware only supports an even clock divisor, so
594 * round divisor = spiclk / speed up to nearest even number
595 * so that the resulting speed is <= the requested speed
596 */
597 writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
598 rs->regs + ROCKCHIP_SPI_BAUDR);
599
600 return 0;
601 }
602
rockchip_spi_max_transfer_size(struct spi_device * spi)603 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
604 {
605 return ROCKCHIP_SPI_MAX_TRANLEN;
606 }
607
rockchip_spi_target_abort(struct spi_controller * ctlr)608 static int rockchip_spi_target_abort(struct spi_controller *ctlr)
609 {
610 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
611 u32 rx_fifo_left;
612 struct dma_tx_state state;
613 enum dma_status status;
614
615 /* Get current dma rx point */
616 if (atomic_read(&rs->state) & RXDMA) {
617 dmaengine_pause(ctlr->dma_rx);
618 status = dmaengine_tx_status(ctlr->dma_rx, ctlr->dma_rx->cookie, &state);
619 if (status == DMA_ERROR) {
620 rs->rx = rs->xfer->rx_buf;
621 rs->xfer->len = 0;
622 rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
623 for (; rx_fifo_left; rx_fifo_left--)
624 readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
625 goto out;
626 } else {
627 rs->rx += rs->xfer->len - rs->n_bytes * state.residue;
628 }
629 }
630
631 /* Get the valid data left in rx fifo and set rs->xfer->len real rx size */
632 if (rs->rx) {
633 rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
634 for (; rx_fifo_left; rx_fifo_left--) {
635 u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
636
637 if (rs->n_bytes == 1)
638 *(u8 *)rs->rx = (u8)rxw;
639 else
640 *(u16 *)rs->rx = (u16)rxw;
641 rs->rx += rs->n_bytes;
642 }
643 rs->xfer->len = (unsigned int)(rs->rx - rs->xfer->rx_buf);
644 }
645
646 out:
647 if (atomic_read(&rs->state) & RXDMA)
648 dmaengine_terminate_sync(ctlr->dma_rx);
649 if (atomic_read(&rs->state) & TXDMA)
650 dmaengine_terminate_sync(ctlr->dma_tx);
651 atomic_set(&rs->state, 0);
652 spi_enable_chip(rs, false);
653 rs->target_abort = true;
654 spi_finalize_current_transfer(ctlr);
655
656 return 0;
657 }
658
rockchip_spi_transfer_one(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * xfer)659 static int rockchip_spi_transfer_one(
660 struct spi_controller *ctlr,
661 struct spi_device *spi,
662 struct spi_transfer *xfer)
663 {
664 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
665 int ret;
666 bool use_dma;
667
668 /* Zero length transfers won't trigger an interrupt on completion */
669 if (!xfer->len) {
670 spi_finalize_current_transfer(ctlr);
671 return 1;
672 }
673
674 WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
675 (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
676
677 if (!xfer->tx_buf && !xfer->rx_buf) {
678 dev_err(rs->dev, "No buffer for transfer\n");
679 return -EINVAL;
680 }
681
682 if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
683 dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
684 return -EINVAL;
685 }
686
687 rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
688 rs->xfer = xfer;
689 use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
690
691 ret = rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->target);
692 if (ret)
693 return ret;
694
695 if (use_dma)
696 return rockchip_spi_prepare_dma(rs, ctlr, xfer);
697
698 return rockchip_spi_prepare_irq(rs, ctlr, xfer);
699 }
700
rockchip_spi_can_dma(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * xfer)701 static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
702 struct spi_device *spi,
703 struct spi_transfer *xfer)
704 {
705 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
706 unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
707
708 /* if the numbor of spi words to transfer is less than the fifo
709 * length we can just fill the fifo and wait for a single irq,
710 * so don't bother setting up dma
711 */
712 return xfer->len / bytes_per_word >= rs->fifo_len;
713 }
714
rockchip_spi_setup(struct spi_device * spi)715 static int rockchip_spi_setup(struct spi_device *spi)
716 {
717 struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
718 u32 cr0;
719
720 if (!spi_get_csgpiod(spi, 0) && (spi->mode & SPI_CS_HIGH) && !rs->cs_high_supported) {
721 dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
722 return -EINVAL;
723 }
724
725 pm_runtime_get_sync(rs->dev);
726
727 cr0 = readl_relaxed(rs->regs + ROCKCHIP_SPI_CTRLR0);
728
729 cr0 &= ~(0x3 << CR0_SCPH_OFFSET);
730 cr0 |= ((spi->mode & 0x3) << CR0_SCPH_OFFSET);
731 if (spi->mode & SPI_CS_HIGH && spi_get_chipselect(spi, 0) <= 1)
732 cr0 |= BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET;
733 else if (spi_get_chipselect(spi, 0) <= 1)
734 cr0 &= ~(BIT(spi_get_chipselect(spi, 0)) << CR0_SOI_OFFSET);
735
736 writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
737
738 pm_runtime_put(rs->dev);
739
740 return 0;
741 }
742
rockchip_spi_probe(struct platform_device * pdev)743 static int rockchip_spi_probe(struct platform_device *pdev)
744 {
745 int ret;
746 struct rockchip_spi *rs;
747 struct spi_controller *ctlr;
748 struct resource *mem;
749 struct device_node *np = pdev->dev.of_node;
750 u32 rsd_nsecs, num_cs;
751 bool target_mode;
752
753 target_mode = of_property_read_bool(np, "spi-slave");
754
755 if (target_mode)
756 ctlr = spi_alloc_target(&pdev->dev,
757 sizeof(struct rockchip_spi));
758 else
759 ctlr = spi_alloc_host(&pdev->dev,
760 sizeof(struct rockchip_spi));
761
762 if (!ctlr)
763 return -ENOMEM;
764
765 platform_set_drvdata(pdev, ctlr);
766
767 rs = spi_controller_get_devdata(ctlr);
768
769 /* Get basic io resource and map it */
770 rs->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
771 if (IS_ERR(rs->regs)) {
772 ret = PTR_ERR(rs->regs);
773 goto err_put_ctlr;
774 }
775
776 rs->apb_pclk = devm_clk_get_enabled(&pdev->dev, "apb_pclk");
777 if (IS_ERR(rs->apb_pclk)) {
778 dev_err(&pdev->dev, "Failed to get apb_pclk\n");
779 ret = PTR_ERR(rs->apb_pclk);
780 goto err_put_ctlr;
781 }
782
783 rs->spiclk = devm_clk_get_enabled(&pdev->dev, "spiclk");
784 if (IS_ERR(rs->spiclk)) {
785 dev_err(&pdev->dev, "Failed to get spi_pclk\n");
786 ret = PTR_ERR(rs->spiclk);
787 goto err_put_ctlr;
788 }
789
790 spi_enable_chip(rs, false);
791
792 ret = platform_get_irq(pdev, 0);
793 if (ret < 0)
794 goto err_put_ctlr;
795
796 ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
797 IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
798 if (ret)
799 goto err_put_ctlr;
800
801 rs->dev = &pdev->dev;
802 rs->freq = clk_get_rate(rs->spiclk);
803
804 if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
805 &rsd_nsecs)) {
806 /* rx sample delay is expressed in parent clock cycles (max 3) */
807 u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
808 1000000000 >> 8);
809 if (!rsd) {
810 dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
811 rs->freq, rsd_nsecs);
812 } else if (rsd > CR0_RSD_MAX) {
813 rsd = CR0_RSD_MAX;
814 dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
815 rs->freq, rsd_nsecs,
816 CR0_RSD_MAX * 1000000000U / rs->freq);
817 }
818 rs->rsd = rsd;
819 }
820
821 rs->fifo_len = get_fifo_len(rs);
822 if (!rs->fifo_len) {
823 dev_err(&pdev->dev, "Failed to get fifo length\n");
824 ret = -EINVAL;
825 goto err_put_ctlr;
826 }
827
828 pm_runtime_set_autosuspend_delay(&pdev->dev, ROCKCHIP_AUTOSUSPEND_TIMEOUT);
829 pm_runtime_use_autosuspend(&pdev->dev);
830 pm_runtime_set_active(&pdev->dev);
831 pm_runtime_enable(&pdev->dev);
832
833 ctlr->auto_runtime_pm = true;
834 ctlr->bus_num = pdev->id;
835 ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
836 if (target_mode) {
837 ctlr->mode_bits |= SPI_NO_CS;
838 ctlr->target_abort = rockchip_spi_target_abort;
839 } else {
840 ctlr->flags = SPI_CONTROLLER_GPIO_SS;
841 ctlr->max_native_cs = ROCKCHIP_SPI_MAX_NATIVE_CS_NUM;
842 /*
843 * rk spi0 has two native cs, spi1..5 one cs only
844 * if num-cs is missing in the dts, default to 1
845 */
846 if (of_property_read_u32(np, "num-cs", &num_cs))
847 num_cs = 1;
848 ctlr->num_chipselect = num_cs;
849 ctlr->use_gpio_descriptors = true;
850 }
851 ctlr->dev.of_node = pdev->dev.of_node;
852 ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
853 ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
854 ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
855
856 ctlr->setup = rockchip_spi_setup;
857 ctlr->set_cs = rockchip_spi_set_cs;
858 ctlr->transfer_one = rockchip_spi_transfer_one;
859 ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
860 ctlr->handle_err = rockchip_spi_handle_err;
861
862 ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
863 if (IS_ERR(ctlr->dma_tx)) {
864 /* Check tx to see if we need defer probing driver */
865 if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
866 ret = -EPROBE_DEFER;
867 goto err_disable_pm_runtime;
868 }
869 dev_warn(rs->dev, "Failed to request TX DMA channel\n");
870 ctlr->dma_tx = NULL;
871 }
872
873 ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
874 if (IS_ERR(ctlr->dma_rx)) {
875 if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
876 ret = -EPROBE_DEFER;
877 goto err_free_dma_tx;
878 }
879 dev_warn(rs->dev, "Failed to request RX DMA channel\n");
880 ctlr->dma_rx = NULL;
881 }
882
883 if (ctlr->dma_tx && ctlr->dma_rx) {
884 rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
885 rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
886 ctlr->can_dma = rockchip_spi_can_dma;
887 }
888
889 switch (readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION)) {
890 case ROCKCHIP_SPI_VER2_TYPE2:
891 rs->cs_high_supported = true;
892 ctlr->mode_bits |= SPI_CS_HIGH;
893 if (ctlr->can_dma && target_mode)
894 rs->cs_inactive = true;
895 else
896 rs->cs_inactive = false;
897 break;
898 default:
899 rs->cs_inactive = false;
900 break;
901 }
902
903 ret = devm_spi_register_controller(&pdev->dev, ctlr);
904 if (ret < 0) {
905 dev_err(&pdev->dev, "Failed to register controller\n");
906 goto err_free_dma_rx;
907 }
908
909 return 0;
910
911 err_free_dma_rx:
912 if (ctlr->dma_rx)
913 dma_release_channel(ctlr->dma_rx);
914 err_free_dma_tx:
915 if (ctlr->dma_tx)
916 dma_release_channel(ctlr->dma_tx);
917 err_disable_pm_runtime:
918 pm_runtime_disable(&pdev->dev);
919 err_put_ctlr:
920 spi_controller_put(ctlr);
921
922 return ret;
923 }
924
rockchip_spi_remove(struct platform_device * pdev)925 static void rockchip_spi_remove(struct platform_device *pdev)
926 {
927 struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
928
929 pm_runtime_get_sync(&pdev->dev);
930
931 pm_runtime_put_noidle(&pdev->dev);
932 pm_runtime_disable(&pdev->dev);
933 pm_runtime_set_suspended(&pdev->dev);
934
935 if (ctlr->dma_tx)
936 dma_release_channel(ctlr->dma_tx);
937 if (ctlr->dma_rx)
938 dma_release_channel(ctlr->dma_rx);
939
940 spi_controller_put(ctlr);
941 }
942
943 #ifdef CONFIG_PM_SLEEP
rockchip_spi_suspend(struct device * dev)944 static int rockchip_spi_suspend(struct device *dev)
945 {
946 int ret;
947 struct spi_controller *ctlr = dev_get_drvdata(dev);
948
949 ret = spi_controller_suspend(ctlr);
950 if (ret < 0)
951 return ret;
952
953 ret = pm_runtime_force_suspend(dev);
954 if (ret < 0) {
955 spi_controller_resume(ctlr);
956 return ret;
957 }
958
959 pinctrl_pm_select_sleep_state(dev);
960
961 return 0;
962 }
963
rockchip_spi_resume(struct device * dev)964 static int rockchip_spi_resume(struct device *dev)
965 {
966 int ret;
967 struct spi_controller *ctlr = dev_get_drvdata(dev);
968
969 pinctrl_pm_select_default_state(dev);
970
971 ret = pm_runtime_force_resume(dev);
972 if (ret < 0)
973 return ret;
974
975 return spi_controller_resume(ctlr);
976 }
977 #endif /* CONFIG_PM_SLEEP */
978
979 #ifdef CONFIG_PM
rockchip_spi_runtime_suspend(struct device * dev)980 static int rockchip_spi_runtime_suspend(struct device *dev)
981 {
982 struct spi_controller *ctlr = dev_get_drvdata(dev);
983 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
984
985 clk_disable_unprepare(rs->spiclk);
986 clk_disable_unprepare(rs->apb_pclk);
987
988 return 0;
989 }
990
rockchip_spi_runtime_resume(struct device * dev)991 static int rockchip_spi_runtime_resume(struct device *dev)
992 {
993 int ret;
994 struct spi_controller *ctlr = dev_get_drvdata(dev);
995 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
996
997 ret = clk_prepare_enable(rs->apb_pclk);
998 if (ret < 0)
999 return ret;
1000
1001 ret = clk_prepare_enable(rs->spiclk);
1002 if (ret < 0)
1003 clk_disable_unprepare(rs->apb_pclk);
1004
1005 return 0;
1006 }
1007 #endif /* CONFIG_PM */
1008
1009 static const struct dev_pm_ops rockchip_spi_pm = {
1010 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
1011 SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
1012 rockchip_spi_runtime_resume, NULL)
1013 };
1014
1015 static const struct of_device_id rockchip_spi_dt_match[] = {
1016 { .compatible = "rockchip,px30-spi", },
1017 { .compatible = "rockchip,rk3036-spi", },
1018 { .compatible = "rockchip,rk3066-spi", },
1019 { .compatible = "rockchip,rk3188-spi", },
1020 { .compatible = "rockchip,rk3228-spi", },
1021 { .compatible = "rockchip,rk3288-spi", },
1022 { .compatible = "rockchip,rk3308-spi", },
1023 { .compatible = "rockchip,rk3328-spi", },
1024 { .compatible = "rockchip,rk3368-spi", },
1025 { .compatible = "rockchip,rk3399-spi", },
1026 { .compatible = "rockchip,rv1108-spi", },
1027 { .compatible = "rockchip,rv1126-spi", },
1028 { },
1029 };
1030 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
1031
1032 static struct platform_driver rockchip_spi_driver = {
1033 .driver = {
1034 .name = DRIVER_NAME,
1035 .pm = &rockchip_spi_pm,
1036 .of_match_table = of_match_ptr(rockchip_spi_dt_match),
1037 },
1038 .probe = rockchip_spi_probe,
1039 .remove_new = rockchip_spi_remove,
1040 };
1041
1042 module_platform_driver(rockchip_spi_driver);
1043
1044 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
1045 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
1046 MODULE_LICENSE("GPL v2");
1047