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_MASTER 0x0
108 #define CR0_OPM_SLAVE 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_SLAVE_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 master 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 /* 2 for native cs, 2 for cs-gpio */
164 #define ROCKCHIP_SPI_MAX_CS_NUM 4
165 #define ROCKCHIP_SPI_VER2_TYPE1 0x05EC0002
166 #define ROCKCHIP_SPI_VER2_TYPE2 0x00110002
167
168 #define ROCKCHIP_AUTOSUSPEND_TIMEOUT 2000
169
170 struct rockchip_spi {
171 struct device *dev;
172
173 struct clk *spiclk;
174 struct clk *apb_pclk;
175
176 void __iomem *regs;
177 dma_addr_t dma_addr_rx;
178 dma_addr_t dma_addr_tx;
179
180 const void *tx;
181 void *rx;
182 unsigned int tx_left;
183 unsigned int rx_left;
184
185 atomic_t state;
186
187 /*depth of the FIFO buffer */
188 u32 fifo_len;
189 /* frequency of spiclk */
190 u32 freq;
191
192 u8 n_bytes;
193 u8 rsd;
194
195 bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];
196
197 bool slave_abort;
198 bool cs_inactive; /* spi slave tansmition stop when cs inactive */
199 bool cs_high_supported; /* native CS supports active-high polarity */
200
201 struct spi_transfer *xfer; /* Store xfer temporarily */
202 };
203
spi_enable_chip(struct rockchip_spi * rs,bool enable)204 static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
205 {
206 writel_relaxed((enable ? 1U : 0U), rs->regs + ROCKCHIP_SPI_SSIENR);
207 }
208
wait_for_tx_idle(struct rockchip_spi * rs,bool slave_mode)209 static inline void wait_for_tx_idle(struct rockchip_spi *rs, bool slave_mode)
210 {
211 unsigned long timeout = jiffies + msecs_to_jiffies(5);
212
213 do {
214 if (slave_mode) {
215 if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_SLAVE_TX_BUSY) &&
216 !((readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY)))
217 return;
218 } else {
219 if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
220 return;
221 }
222 } while (!time_after(jiffies, timeout));
223
224 dev_warn(rs->dev, "spi controller is in busy state!\n");
225 }
226
get_fifo_len(struct rockchip_spi * rs)227 static u32 get_fifo_len(struct rockchip_spi *rs)
228 {
229 u32 ver;
230
231 ver = readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION);
232
233 switch (ver) {
234 case ROCKCHIP_SPI_VER2_TYPE1:
235 case ROCKCHIP_SPI_VER2_TYPE2:
236 return 64;
237 default:
238 return 32;
239 }
240 }
241
rockchip_spi_set_cs(struct spi_device * spi,bool enable)242 static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
243 {
244 struct spi_controller *ctlr = spi->controller;
245 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
246 bool cs_asserted = spi->mode & SPI_CS_HIGH ? enable : !enable;
247
248 /* Return immediately for no-op */
249 if (cs_asserted == rs->cs_asserted[spi->chip_select])
250 return;
251
252 if (cs_asserted) {
253 /* Keep things powered as long as CS is asserted */
254 pm_runtime_get_sync(rs->dev);
255
256 if (spi->cs_gpiod)
257 ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
258 else
259 ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));
260 } else {
261 if (spi->cs_gpiod)
262 ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
263 else
264 ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));
265
266 /* Drop reference from when we first asserted CS */
267 pm_runtime_put(rs->dev);
268 }
269
270 rs->cs_asserted[spi->chip_select] = cs_asserted;
271 }
272
rockchip_spi_handle_err(struct spi_controller * ctlr,struct spi_message * msg)273 static void rockchip_spi_handle_err(struct spi_controller *ctlr,
274 struct spi_message *msg)
275 {
276 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
277
278 /* stop running spi transfer
279 * this also flushes both rx and tx fifos
280 */
281 spi_enable_chip(rs, false);
282
283 /* make sure all interrupts are masked */
284 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
285
286 if (atomic_read(&rs->state) & TXDMA)
287 dmaengine_terminate_async(ctlr->dma_tx);
288
289 if (atomic_read(&rs->state) & RXDMA)
290 dmaengine_terminate_async(ctlr->dma_rx);
291 }
292
rockchip_spi_pio_writer(struct rockchip_spi * rs)293 static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
294 {
295 u32 tx_free = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
296 u32 words = min(rs->tx_left, tx_free);
297
298 rs->tx_left -= words;
299 for (; words; words--) {
300 u32 txw;
301
302 if (rs->n_bytes == 1)
303 txw = *(u8 *)rs->tx;
304 else
305 txw = *(u16 *)rs->tx;
306
307 writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
308 rs->tx += rs->n_bytes;
309 }
310 }
311
rockchip_spi_pio_reader(struct rockchip_spi * rs)312 static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
313 {
314 u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
315 u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
316
317 /* the hardware doesn't allow us to change fifo threshold
318 * level while spi is enabled, so instead make sure to leave
319 * enough words in the rx fifo to get the last interrupt
320 * exactly when all words have been received
321 */
322 if (rx_left) {
323 u32 ftl = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFTLR) + 1;
324
325 if (rx_left < ftl) {
326 rx_left = ftl;
327 words = rs->rx_left - rx_left;
328 }
329 }
330
331 rs->rx_left = rx_left;
332 for (; words; words--) {
333 u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
334
335 if (!rs->rx)
336 continue;
337
338 if (rs->n_bytes == 1)
339 *(u8 *)rs->rx = (u8)rxw;
340 else
341 *(u16 *)rs->rx = (u16)rxw;
342 rs->rx += rs->n_bytes;
343 }
344 }
345
rockchip_spi_isr(int irq,void * dev_id)346 static irqreturn_t rockchip_spi_isr(int irq, void *dev_id)
347 {
348 struct spi_controller *ctlr = dev_id;
349 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
350
351 /* When int_cs_inactive comes, spi slave abort */
352 if (rs->cs_inactive && readl_relaxed(rs->regs + ROCKCHIP_SPI_IMR) & INT_CS_INACTIVE) {
353 ctlr->slave_abort(ctlr);
354 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
355 writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
356
357 return IRQ_HANDLED;
358 }
359
360 if (rs->tx_left)
361 rockchip_spi_pio_writer(rs);
362
363 rockchip_spi_pio_reader(rs);
364 if (!rs->rx_left) {
365 spi_enable_chip(rs, false);
366 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
367 writel_relaxed(0xffffffff, rs->regs + ROCKCHIP_SPI_ICR);
368 spi_finalize_current_transfer(ctlr);
369 }
370
371 return IRQ_HANDLED;
372 }
373
rockchip_spi_prepare_irq(struct rockchip_spi * rs,struct spi_controller * ctlr,struct spi_transfer * xfer)374 static int rockchip_spi_prepare_irq(struct rockchip_spi *rs,
375 struct spi_controller *ctlr,
376 struct spi_transfer *xfer)
377 {
378 rs->tx = xfer->tx_buf;
379 rs->rx = xfer->rx_buf;
380 rs->tx_left = rs->tx ? xfer->len / rs->n_bytes : 0;
381 rs->rx_left = xfer->len / rs->n_bytes;
382
383 if (rs->cs_inactive)
384 writel_relaxed(INT_RF_FULL | INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
385 else
386 writel_relaxed(INT_RF_FULL, rs->regs + ROCKCHIP_SPI_IMR);
387 spi_enable_chip(rs, true);
388
389 if (rs->tx_left)
390 rockchip_spi_pio_writer(rs);
391
392 /* 1 means the transfer is in progress */
393 return 1;
394 }
395
rockchip_spi_dma_rxcb(void * data)396 static void rockchip_spi_dma_rxcb(void *data)
397 {
398 struct spi_controller *ctlr = data;
399 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
400 int state = atomic_fetch_andnot(RXDMA, &rs->state);
401
402 if (state & TXDMA && !rs->slave_abort)
403 return;
404
405 if (rs->cs_inactive)
406 writel_relaxed(0, rs->regs + ROCKCHIP_SPI_IMR);
407
408 spi_enable_chip(rs, false);
409 spi_finalize_current_transfer(ctlr);
410 }
411
rockchip_spi_dma_txcb(void * data)412 static void rockchip_spi_dma_txcb(void *data)
413 {
414 struct spi_controller *ctlr = data;
415 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
416 int state = atomic_fetch_andnot(TXDMA, &rs->state);
417
418 if (state & RXDMA && !rs->slave_abort)
419 return;
420
421 /* Wait until the FIFO data completely. */
422 wait_for_tx_idle(rs, ctlr->slave);
423
424 spi_enable_chip(rs, false);
425 spi_finalize_current_transfer(ctlr);
426 }
427
rockchip_spi_calc_burst_size(u32 data_len)428 static u32 rockchip_spi_calc_burst_size(u32 data_len)
429 {
430 u32 i;
431
432 /* burst size: 1, 2, 4, 8 */
433 for (i = 1; i < 8; i <<= 1) {
434 if (data_len & i)
435 break;
436 }
437
438 return i;
439 }
440
rockchip_spi_prepare_dma(struct rockchip_spi * rs,struct spi_controller * ctlr,struct spi_transfer * xfer)441 static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,
442 struct spi_controller *ctlr, struct spi_transfer *xfer)
443 {
444 struct dma_async_tx_descriptor *rxdesc, *txdesc;
445
446 atomic_set(&rs->state, 0);
447
448 rs->tx = xfer->tx_buf;
449 rs->rx = xfer->rx_buf;
450
451 rxdesc = NULL;
452 if (xfer->rx_buf) {
453 struct dma_slave_config rxconf = {
454 .direction = DMA_DEV_TO_MEM,
455 .src_addr = rs->dma_addr_rx,
456 .src_addr_width = rs->n_bytes,
457 .src_maxburst = rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes),
458 };
459
460 dmaengine_slave_config(ctlr->dma_rx, &rxconf);
461
462 rxdesc = dmaengine_prep_slave_sg(
463 ctlr->dma_rx,
464 xfer->rx_sg.sgl, xfer->rx_sg.nents,
465 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
466 if (!rxdesc)
467 return -EINVAL;
468
469 rxdesc->callback = rockchip_spi_dma_rxcb;
470 rxdesc->callback_param = ctlr;
471 }
472
473 txdesc = NULL;
474 if (xfer->tx_buf) {
475 struct dma_slave_config txconf = {
476 .direction = DMA_MEM_TO_DEV,
477 .dst_addr = rs->dma_addr_tx,
478 .dst_addr_width = rs->n_bytes,
479 .dst_maxburst = rs->fifo_len / 4,
480 };
481
482 dmaengine_slave_config(ctlr->dma_tx, &txconf);
483
484 txdesc = dmaengine_prep_slave_sg(
485 ctlr->dma_tx,
486 xfer->tx_sg.sgl, xfer->tx_sg.nents,
487 DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
488 if (!txdesc) {
489 if (rxdesc)
490 dmaengine_terminate_sync(ctlr->dma_rx);
491 return -EINVAL;
492 }
493
494 txdesc->callback = rockchip_spi_dma_txcb;
495 txdesc->callback_param = ctlr;
496 }
497
498 /* rx must be started before tx due to spi instinct */
499 if (rxdesc) {
500 atomic_or(RXDMA, &rs->state);
501 ctlr->dma_rx->cookie = dmaengine_submit(rxdesc);
502 dma_async_issue_pending(ctlr->dma_rx);
503 }
504
505 if (rs->cs_inactive)
506 writel_relaxed(INT_CS_INACTIVE, rs->regs + ROCKCHIP_SPI_IMR);
507
508 spi_enable_chip(rs, true);
509
510 if (txdesc) {
511 atomic_or(TXDMA, &rs->state);
512 dmaengine_submit(txdesc);
513 dma_async_issue_pending(ctlr->dma_tx);
514 }
515
516 /* 1 means the transfer is in progress */
517 return 1;
518 }
519
rockchip_spi_config(struct rockchip_spi * rs,struct spi_device * spi,struct spi_transfer * xfer,bool use_dma,bool slave_mode)520 static int rockchip_spi_config(struct rockchip_spi *rs,
521 struct spi_device *spi, struct spi_transfer *xfer,
522 bool use_dma, bool slave_mode)
523 {
524 u32 cr0 = CR0_FRF_SPI << CR0_FRF_OFFSET
525 | CR0_BHT_8BIT << CR0_BHT_OFFSET
526 | CR0_SSD_ONE << CR0_SSD_OFFSET
527 | CR0_EM_BIG << CR0_EM_OFFSET;
528 u32 cr1;
529 u32 dmacr = 0;
530
531 if (slave_mode)
532 cr0 |= CR0_OPM_SLAVE << CR0_OPM_OFFSET;
533 rs->slave_abort = false;
534
535 cr0 |= rs->rsd << CR0_RSD_OFFSET;
536 cr0 |= (spi->mode & 0x3U) << CR0_SCPH_OFFSET;
537 if (spi->mode & SPI_LSB_FIRST)
538 cr0 |= CR0_FBM_LSB << CR0_FBM_OFFSET;
539 if (spi->mode & SPI_CS_HIGH)
540 cr0 |= BIT(spi->chip_select) << CR0_SOI_OFFSET;
541
542 if (xfer->rx_buf && xfer->tx_buf)
543 cr0 |= CR0_XFM_TR << CR0_XFM_OFFSET;
544 else if (xfer->rx_buf)
545 cr0 |= CR0_XFM_RO << CR0_XFM_OFFSET;
546 else if (use_dma)
547 cr0 |= CR0_XFM_TO << CR0_XFM_OFFSET;
548
549 switch (xfer->bits_per_word) {
550 case 4:
551 cr0 |= CR0_DFS_4BIT << CR0_DFS_OFFSET;
552 cr1 = xfer->len - 1;
553 break;
554 case 8:
555 cr0 |= CR0_DFS_8BIT << CR0_DFS_OFFSET;
556 cr1 = xfer->len - 1;
557 break;
558 case 16:
559 cr0 |= CR0_DFS_16BIT << CR0_DFS_OFFSET;
560 cr1 = xfer->len / 2 - 1;
561 break;
562 default:
563 /* we only whitelist 4, 8 and 16 bit words in
564 * ctlr->bits_per_word_mask, so this shouldn't
565 * happen
566 */
567 dev_err(rs->dev, "unknown bits per word: %d\n",
568 xfer->bits_per_word);
569 return -EINVAL;
570 }
571
572 if (use_dma) {
573 if (xfer->tx_buf)
574 dmacr |= TF_DMA_EN;
575 if (xfer->rx_buf)
576 dmacr |= RF_DMA_EN;
577 }
578
579 writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
580 writel_relaxed(cr1, rs->regs + ROCKCHIP_SPI_CTRLR1);
581
582 /* unfortunately setting the fifo threshold level to generate an
583 * interrupt exactly when the fifo is full doesn't seem to work,
584 * so we need the strict inequality here
585 */
586 if ((xfer->len / rs->n_bytes) < rs->fifo_len)
587 writel_relaxed(xfer->len / rs->n_bytes - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
588 else
589 writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
590
591 writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
592 writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,
593 rs->regs + ROCKCHIP_SPI_DMARDLR);
594 writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
595
596 /* the hardware only supports an even clock divisor, so
597 * round divisor = spiclk / speed up to nearest even number
598 * so that the resulting speed is <= the requested speed
599 */
600 writel_relaxed(2 * DIV_ROUND_UP(rs->freq, 2 * xfer->speed_hz),
601 rs->regs + ROCKCHIP_SPI_BAUDR);
602
603 return 0;
604 }
605
rockchip_spi_max_transfer_size(struct spi_device * spi)606 static size_t rockchip_spi_max_transfer_size(struct spi_device *spi)
607 {
608 return ROCKCHIP_SPI_MAX_TRANLEN;
609 }
610
rockchip_spi_slave_abort(struct spi_controller * ctlr)611 static int rockchip_spi_slave_abort(struct spi_controller *ctlr)
612 {
613 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
614 u32 rx_fifo_left;
615 struct dma_tx_state state;
616 enum dma_status status;
617
618 /* Get current dma rx point */
619 if (atomic_read(&rs->state) & RXDMA) {
620 dmaengine_pause(ctlr->dma_rx);
621 status = dmaengine_tx_status(ctlr->dma_rx, ctlr->dma_rx->cookie, &state);
622 if (status == DMA_ERROR) {
623 rs->rx = rs->xfer->rx_buf;
624 rs->xfer->len = 0;
625 rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
626 for (; rx_fifo_left; rx_fifo_left--)
627 readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
628 goto out;
629 } else {
630 rs->rx += rs->xfer->len - rs->n_bytes * state.residue;
631 }
632 }
633
634 /* Get the valid data left in rx fifo and set rs->xfer->len real rx size */
635 if (rs->rx) {
636 rx_fifo_left = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
637 for (; rx_fifo_left; rx_fifo_left--) {
638 u32 rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
639
640 if (rs->n_bytes == 1)
641 *(u8 *)rs->rx = (u8)rxw;
642 else
643 *(u16 *)rs->rx = (u16)rxw;
644 rs->rx += rs->n_bytes;
645 }
646 rs->xfer->len = (unsigned int)(rs->rx - rs->xfer->rx_buf);
647 }
648
649 out:
650 if (atomic_read(&rs->state) & RXDMA)
651 dmaengine_terminate_sync(ctlr->dma_rx);
652 if (atomic_read(&rs->state) & TXDMA)
653 dmaengine_terminate_sync(ctlr->dma_tx);
654 atomic_set(&rs->state, 0);
655 spi_enable_chip(rs, false);
656 rs->slave_abort = true;
657 spi_finalize_current_transfer(ctlr);
658
659 return 0;
660 }
661
rockchip_spi_transfer_one(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * xfer)662 static int rockchip_spi_transfer_one(
663 struct spi_controller *ctlr,
664 struct spi_device *spi,
665 struct spi_transfer *xfer)
666 {
667 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
668 int ret;
669 bool use_dma;
670
671 /* Zero length transfers won't trigger an interrupt on completion */
672 if (!xfer->len) {
673 spi_finalize_current_transfer(ctlr);
674 return 1;
675 }
676
677 WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
678 (readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
679
680 if (!xfer->tx_buf && !xfer->rx_buf) {
681 dev_err(rs->dev, "No buffer for transfer\n");
682 return -EINVAL;
683 }
684
685 if (xfer->len > ROCKCHIP_SPI_MAX_TRANLEN) {
686 dev_err(rs->dev, "Transfer is too long (%d)\n", xfer->len);
687 return -EINVAL;
688 }
689
690 rs->n_bytes = xfer->bits_per_word <= 8 ? 1 : 2;
691 rs->xfer = xfer;
692 use_dma = ctlr->can_dma ? ctlr->can_dma(ctlr, spi, xfer) : false;
693
694 ret = rockchip_spi_config(rs, spi, xfer, use_dma, ctlr->slave);
695 if (ret)
696 return ret;
697
698 if (use_dma)
699 return rockchip_spi_prepare_dma(rs, ctlr, xfer);
700
701 return rockchip_spi_prepare_irq(rs, ctlr, xfer);
702 }
703
rockchip_spi_can_dma(struct spi_controller * ctlr,struct spi_device * spi,struct spi_transfer * xfer)704 static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
705 struct spi_device *spi,
706 struct spi_transfer *xfer)
707 {
708 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
709 unsigned int bytes_per_word = xfer->bits_per_word <= 8 ? 1 : 2;
710
711 /* if the numbor of spi words to transfer is less than the fifo
712 * length we can just fill the fifo and wait for a single irq,
713 * so don't bother setting up dma
714 */
715 return xfer->len / bytes_per_word >= rs->fifo_len;
716 }
717
rockchip_spi_setup(struct spi_device * spi)718 static int rockchip_spi_setup(struct spi_device *spi)
719 {
720 struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
721 u32 cr0;
722
723 if (!spi->cs_gpiod && (spi->mode & SPI_CS_HIGH) && !rs->cs_high_supported) {
724 dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n");
725 return -EINVAL;
726 }
727
728 pm_runtime_get_sync(rs->dev);
729
730 cr0 = readl_relaxed(rs->regs + ROCKCHIP_SPI_CTRLR0);
731
732 cr0 &= ~(0x3 << CR0_SCPH_OFFSET);
733 cr0 |= ((spi->mode & 0x3) << CR0_SCPH_OFFSET);
734 if (spi->mode & SPI_CS_HIGH && spi->chip_select <= 1)
735 cr0 |= BIT(spi->chip_select) << CR0_SOI_OFFSET;
736 else if (spi->chip_select <= 1)
737 cr0 &= ~(BIT(spi->chip_select) << CR0_SOI_OFFSET);
738
739 writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
740
741 pm_runtime_put(rs->dev);
742
743 return 0;
744 }
745
rockchip_spi_probe(struct platform_device * pdev)746 static int rockchip_spi_probe(struct platform_device *pdev)
747 {
748 int ret;
749 struct rockchip_spi *rs;
750 struct spi_controller *ctlr;
751 struct resource *mem;
752 struct device_node *np = pdev->dev.of_node;
753 u32 rsd_nsecs, num_cs;
754 bool slave_mode;
755
756 slave_mode = of_property_read_bool(np, "spi-slave");
757
758 if (slave_mode)
759 ctlr = spi_alloc_slave(&pdev->dev,
760 sizeof(struct rockchip_spi));
761 else
762 ctlr = spi_alloc_master(&pdev->dev,
763 sizeof(struct rockchip_spi));
764
765 if (!ctlr)
766 return -ENOMEM;
767
768 platform_set_drvdata(pdev, ctlr);
769
770 rs = spi_controller_get_devdata(ctlr);
771 ctlr->slave = slave_mode;
772
773 /* Get basic io resource and map it */
774 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
775 rs->regs = devm_ioremap_resource(&pdev->dev, mem);
776 if (IS_ERR(rs->regs)) {
777 ret = PTR_ERR(rs->regs);
778 goto err_put_ctlr;
779 }
780
781 rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
782 if (IS_ERR(rs->apb_pclk)) {
783 dev_err(&pdev->dev, "Failed to get apb_pclk\n");
784 ret = PTR_ERR(rs->apb_pclk);
785 goto err_put_ctlr;
786 }
787
788 rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
789 if (IS_ERR(rs->spiclk)) {
790 dev_err(&pdev->dev, "Failed to get spi_pclk\n");
791 ret = PTR_ERR(rs->spiclk);
792 goto err_put_ctlr;
793 }
794
795 ret = clk_prepare_enable(rs->apb_pclk);
796 if (ret < 0) {
797 dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
798 goto err_put_ctlr;
799 }
800
801 ret = clk_prepare_enable(rs->spiclk);
802 if (ret < 0) {
803 dev_err(&pdev->dev, "Failed to enable spi_clk\n");
804 goto err_disable_apbclk;
805 }
806
807 spi_enable_chip(rs, false);
808
809 ret = platform_get_irq(pdev, 0);
810 if (ret < 0)
811 goto err_disable_spiclk;
812
813 ret = devm_request_threaded_irq(&pdev->dev, ret, rockchip_spi_isr, NULL,
814 IRQF_ONESHOT, dev_name(&pdev->dev), ctlr);
815 if (ret)
816 goto err_disable_spiclk;
817
818 rs->dev = &pdev->dev;
819 rs->freq = clk_get_rate(rs->spiclk);
820
821 if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
822 &rsd_nsecs)) {
823 /* rx sample delay is expressed in parent clock cycles (max 3) */
824 u32 rsd = DIV_ROUND_CLOSEST(rsd_nsecs * (rs->freq >> 8),
825 1000000000 >> 8);
826 if (!rsd) {
827 dev_warn(rs->dev, "%u Hz are too slow to express %u ns delay\n",
828 rs->freq, rsd_nsecs);
829 } else if (rsd > CR0_RSD_MAX) {
830 rsd = CR0_RSD_MAX;
831 dev_warn(rs->dev, "%u Hz are too fast to express %u ns delay, clamping at %u ns\n",
832 rs->freq, rsd_nsecs,
833 CR0_RSD_MAX * 1000000000U / rs->freq);
834 }
835 rs->rsd = rsd;
836 }
837
838 rs->fifo_len = get_fifo_len(rs);
839 if (!rs->fifo_len) {
840 dev_err(&pdev->dev, "Failed to get fifo length\n");
841 ret = -EINVAL;
842 goto err_disable_spiclk;
843 }
844
845 pm_runtime_set_autosuspend_delay(&pdev->dev, ROCKCHIP_AUTOSUSPEND_TIMEOUT);
846 pm_runtime_use_autosuspend(&pdev->dev);
847 pm_runtime_set_active(&pdev->dev);
848 pm_runtime_enable(&pdev->dev);
849
850 ctlr->auto_runtime_pm = true;
851 ctlr->bus_num = pdev->id;
852 ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_LSB_FIRST;
853 if (slave_mode) {
854 ctlr->mode_bits |= SPI_NO_CS;
855 ctlr->slave_abort = rockchip_spi_slave_abort;
856 } else {
857 ctlr->flags = SPI_MASTER_GPIO_SS;
858 ctlr->max_native_cs = ROCKCHIP_SPI_MAX_CS_NUM;
859 /*
860 * rk spi0 has two native cs, spi1..5 one cs only
861 * if num-cs is missing in the dts, default to 1
862 */
863 if (of_property_read_u32(np, "num-cs", &num_cs))
864 num_cs = 1;
865 ctlr->num_chipselect = num_cs;
866 ctlr->use_gpio_descriptors = true;
867 }
868 ctlr->dev.of_node = pdev->dev.of_node;
869 ctlr->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8) | SPI_BPW_MASK(4);
870 ctlr->min_speed_hz = rs->freq / BAUDR_SCKDV_MAX;
871 ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);
872
873 ctlr->setup = rockchip_spi_setup;
874 ctlr->set_cs = rockchip_spi_set_cs;
875 ctlr->transfer_one = rockchip_spi_transfer_one;
876 ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
877 ctlr->handle_err = rockchip_spi_handle_err;
878
879 ctlr->dma_tx = dma_request_chan(rs->dev, "tx");
880 if (IS_ERR(ctlr->dma_tx)) {
881 /* Check tx to see if we need defer probing driver */
882 if (PTR_ERR(ctlr->dma_tx) == -EPROBE_DEFER) {
883 ret = -EPROBE_DEFER;
884 goto err_disable_pm_runtime;
885 }
886 dev_warn(rs->dev, "Failed to request TX DMA channel\n");
887 ctlr->dma_tx = NULL;
888 }
889
890 ctlr->dma_rx = dma_request_chan(rs->dev, "rx");
891 if (IS_ERR(ctlr->dma_rx)) {
892 if (PTR_ERR(ctlr->dma_rx) == -EPROBE_DEFER) {
893 ret = -EPROBE_DEFER;
894 goto err_free_dma_tx;
895 }
896 dev_warn(rs->dev, "Failed to request RX DMA channel\n");
897 ctlr->dma_rx = NULL;
898 }
899
900 if (ctlr->dma_tx && ctlr->dma_rx) {
901 rs->dma_addr_tx = mem->start + ROCKCHIP_SPI_TXDR;
902 rs->dma_addr_rx = mem->start + ROCKCHIP_SPI_RXDR;
903 ctlr->can_dma = rockchip_spi_can_dma;
904 }
905
906 switch (readl_relaxed(rs->regs + ROCKCHIP_SPI_VERSION)) {
907 case ROCKCHIP_SPI_VER2_TYPE2:
908 rs->cs_high_supported = true;
909 ctlr->mode_bits |= SPI_CS_HIGH;
910 if (ctlr->can_dma && slave_mode)
911 rs->cs_inactive = true;
912 else
913 rs->cs_inactive = false;
914 break;
915 default:
916 rs->cs_inactive = false;
917 break;
918 }
919
920 ret = devm_spi_register_controller(&pdev->dev, ctlr);
921 if (ret < 0) {
922 dev_err(&pdev->dev, "Failed to register controller\n");
923 goto err_free_dma_rx;
924 }
925
926 return 0;
927
928 err_free_dma_rx:
929 if (ctlr->dma_rx)
930 dma_release_channel(ctlr->dma_rx);
931 err_free_dma_tx:
932 if (ctlr->dma_tx)
933 dma_release_channel(ctlr->dma_tx);
934 err_disable_pm_runtime:
935 pm_runtime_disable(&pdev->dev);
936 err_disable_spiclk:
937 clk_disable_unprepare(rs->spiclk);
938 err_disable_apbclk:
939 clk_disable_unprepare(rs->apb_pclk);
940 err_put_ctlr:
941 spi_controller_put(ctlr);
942
943 return ret;
944 }
945
rockchip_spi_remove(struct platform_device * pdev)946 static int rockchip_spi_remove(struct platform_device *pdev)
947 {
948 struct spi_controller *ctlr = spi_controller_get(platform_get_drvdata(pdev));
949 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
950
951 pm_runtime_get_sync(&pdev->dev);
952
953 clk_disable_unprepare(rs->spiclk);
954 clk_disable_unprepare(rs->apb_pclk);
955
956 pm_runtime_put_noidle(&pdev->dev);
957 pm_runtime_disable(&pdev->dev);
958 pm_runtime_set_suspended(&pdev->dev);
959
960 if (ctlr->dma_tx)
961 dma_release_channel(ctlr->dma_tx);
962 if (ctlr->dma_rx)
963 dma_release_channel(ctlr->dma_rx);
964
965 spi_controller_put(ctlr);
966
967 return 0;
968 }
969
970 #ifdef CONFIG_PM_SLEEP
rockchip_spi_suspend(struct device * dev)971 static int rockchip_spi_suspend(struct device *dev)
972 {
973 int ret;
974 struct spi_controller *ctlr = dev_get_drvdata(dev);
975
976 ret = spi_controller_suspend(ctlr);
977 if (ret < 0)
978 return ret;
979
980 ret = pm_runtime_force_suspend(dev);
981 if (ret < 0)
982 return ret;
983
984 pinctrl_pm_select_sleep_state(dev);
985
986 return 0;
987 }
988
rockchip_spi_resume(struct device * dev)989 static int rockchip_spi_resume(struct device *dev)
990 {
991 int ret;
992 struct spi_controller *ctlr = dev_get_drvdata(dev);
993 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
994
995 pinctrl_pm_select_default_state(dev);
996
997 ret = pm_runtime_force_resume(dev);
998 if (ret < 0)
999 return ret;
1000
1001 ret = spi_controller_resume(ctlr);
1002 if (ret < 0) {
1003 clk_disable_unprepare(rs->spiclk);
1004 clk_disable_unprepare(rs->apb_pclk);
1005 }
1006
1007 return 0;
1008 }
1009 #endif /* CONFIG_PM_SLEEP */
1010
1011 #ifdef CONFIG_PM
rockchip_spi_runtime_suspend(struct device * dev)1012 static int rockchip_spi_runtime_suspend(struct device *dev)
1013 {
1014 struct spi_controller *ctlr = dev_get_drvdata(dev);
1015 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
1016
1017 clk_disable_unprepare(rs->spiclk);
1018 clk_disable_unprepare(rs->apb_pclk);
1019
1020 return 0;
1021 }
1022
rockchip_spi_runtime_resume(struct device * dev)1023 static int rockchip_spi_runtime_resume(struct device *dev)
1024 {
1025 int ret;
1026 struct spi_controller *ctlr = dev_get_drvdata(dev);
1027 struct rockchip_spi *rs = spi_controller_get_devdata(ctlr);
1028
1029 ret = clk_prepare_enable(rs->apb_pclk);
1030 if (ret < 0)
1031 return ret;
1032
1033 ret = clk_prepare_enable(rs->spiclk);
1034 if (ret < 0)
1035 clk_disable_unprepare(rs->apb_pclk);
1036
1037 return 0;
1038 }
1039 #endif /* CONFIG_PM */
1040
1041 static const struct dev_pm_ops rockchip_spi_pm = {
1042 SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
1043 SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
1044 rockchip_spi_runtime_resume, NULL)
1045 };
1046
1047 static const struct of_device_id rockchip_spi_dt_match[] = {
1048 { .compatible = "rockchip,px30-spi", },
1049 { .compatible = "rockchip,rk3036-spi", },
1050 { .compatible = "rockchip,rk3066-spi", },
1051 { .compatible = "rockchip,rk3188-spi", },
1052 { .compatible = "rockchip,rk3228-spi", },
1053 { .compatible = "rockchip,rk3288-spi", },
1054 { .compatible = "rockchip,rk3308-spi", },
1055 { .compatible = "rockchip,rk3328-spi", },
1056 { .compatible = "rockchip,rk3368-spi", },
1057 { .compatible = "rockchip,rk3399-spi", },
1058 { .compatible = "rockchip,rv1108-spi", },
1059 { .compatible = "rockchip,rv1126-spi", },
1060 { },
1061 };
1062 MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
1063
1064 static struct platform_driver rockchip_spi_driver = {
1065 .driver = {
1066 .name = DRIVER_NAME,
1067 .pm = &rockchip_spi_pm,
1068 .of_match_table = of_match_ptr(rockchip_spi_dt_match),
1069 },
1070 .probe = rockchip_spi_probe,
1071 .remove = rockchip_spi_remove,
1072 };
1073
1074 module_platform_driver(rockchip_spi_driver);
1075
1076 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
1077 MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
1078 MODULE_LICENSE("GPL v2");
1079