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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2012 - 2014 Allwinner Tech
4 * Pan Nan <pannan@allwinnertech.com>
5 *
6 * Copyright (C) 2014 Maxime Ripard
7 * Maxime Ripard <maxime.ripard@free-electrons.com>
8 */
9
10#include <linux/bitfield.h>
11#include <linux/clk.h>
12#include <linux/delay.h>
13#include <linux/device.h>
14#include <linux/interrupt.h>
15#include <linux/io.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/platform_device.h>
19#include <linux/pm_runtime.h>
20#include <linux/reset.h>
21#include <linux/dmaengine.h>
22
23#include <linux/spi/spi.h>
24
25#define SUN6I_AUTOSUSPEND_TIMEOUT 2000
26
27#define SUN6I_FIFO_DEPTH 128
28#define SUN8I_FIFO_DEPTH 64
29
30#define SUN6I_GBL_CTL_REG 0x04
31#define SUN6I_GBL_CTL_BUS_ENABLE BIT(0)
32#define SUN6I_GBL_CTL_MASTER BIT(1)
33#define SUN6I_GBL_CTL_TP BIT(7)
34#define SUN6I_GBL_CTL_RST BIT(31)
35
36#define SUN6I_TFR_CTL_REG 0x08
37#define SUN6I_TFR_CTL_CPHA BIT(0)
38#define SUN6I_TFR_CTL_CPOL BIT(1)
39#define SUN6I_TFR_CTL_SPOL BIT(2)
40#define SUN6I_TFR_CTL_CS_MASK 0x30
41#define SUN6I_TFR_CTL_CS(cs) (((cs) << 4) & SUN6I_TFR_CTL_CS_MASK)
42#define SUN6I_TFR_CTL_CS_MANUAL BIT(6)
43#define SUN6I_TFR_CTL_CS_LEVEL BIT(7)
44#define SUN6I_TFR_CTL_DHB BIT(8)
45#define SUN6I_TFR_CTL_SDC BIT(11)
46#define SUN6I_TFR_CTL_FBS BIT(12)
47#define SUN6I_TFR_CTL_SDM BIT(13)
48#define SUN6I_TFR_CTL_XCH BIT(31)
49
50#define SUN6I_INT_CTL_REG 0x10
51#define SUN6I_INT_CTL_RF_RDY BIT(0)
52#define SUN6I_INT_CTL_TF_ERQ BIT(4)
53#define SUN6I_INT_CTL_RF_OVF BIT(8)
54#define SUN6I_INT_CTL_TC BIT(12)
55
56#define SUN6I_INT_STA_REG 0x14
57
58#define SUN6I_FIFO_CTL_REG 0x18
59#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_MASK 0xff
60#define SUN6I_FIFO_CTL_RF_DRQ_EN BIT(8)
61#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS 0
62#define SUN6I_FIFO_CTL_RF_RST BIT(15)
63#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_MASK 0xff
64#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS 16
65#define SUN6I_FIFO_CTL_TF_DRQ_EN BIT(24)
66#define SUN6I_FIFO_CTL_TF_RST BIT(31)
67
68#define SUN6I_FIFO_STA_REG 0x1c
69#define SUN6I_FIFO_STA_RF_CNT_MASK GENMASK(7, 0)
70#define SUN6I_FIFO_STA_TF_CNT_MASK GENMASK(23, 16)
71
72#define SUN6I_CLK_CTL_REG 0x24
73#define SUN6I_CLK_CTL_CDR2_MASK 0xff
74#define SUN6I_CLK_CTL_CDR2(div) (((div) & SUN6I_CLK_CTL_CDR2_MASK) << 0)
75#define SUN6I_CLK_CTL_CDR1_MASK 0xf
76#define SUN6I_CLK_CTL_CDR1(div) (((div) & SUN6I_CLK_CTL_CDR1_MASK) << 8)
77#define SUN6I_CLK_CTL_DRS BIT(12)
78
79#define SUN6I_MAX_XFER_SIZE 0xffffff
80
81#define SUN6I_BURST_CNT_REG 0x30
82
83#define SUN6I_XMIT_CNT_REG 0x34
84
85#define SUN6I_BURST_CTL_CNT_REG 0x38
86#define SUN6I_BURST_CTL_CNT_STC_MASK GENMASK(23, 0)
87#define SUN6I_BURST_CTL_CNT_DRM BIT(28)
88#define SUN6I_BURST_CTL_CNT_QUAD_EN BIT(29)
89
90#define SUN6I_TXDATA_REG 0x200
91#define SUN6I_RXDATA_REG 0x300
92
93struct sun6i_spi_cfg {
94 unsigned long fifo_depth;
95 bool has_clk_ctl;
96 u32 mode_bits;
97};
98
99struct sun6i_spi {
100 struct spi_controller *host;
101 void __iomem *base_addr;
102 dma_addr_t dma_addr_rx;
103 dma_addr_t dma_addr_tx;
104 struct clk *hclk;
105 struct clk *mclk;
106 struct reset_control *rstc;
107
108 struct completion done;
109 struct completion dma_rx_done;
110
111 const u8 *tx_buf;
112 u8 *rx_buf;
113 int len;
114 const struct sun6i_spi_cfg *cfg;
115};
116
117static inline u32 sun6i_spi_read(struct sun6i_spi *sspi, u32 reg)
118{
119 return readl(sspi->base_addr + reg);
120}
121
122static inline void sun6i_spi_write(struct sun6i_spi *sspi, u32 reg, u32 value)
123{
124 writel(value, sspi->base_addr + reg);
125}
126
127static inline u32 sun6i_spi_get_rx_fifo_count(struct sun6i_spi *sspi)
128{
129 u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
130
131 return FIELD_GET(SUN6I_FIFO_STA_RF_CNT_MASK, reg);
132}
133
134static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
135{
136 u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
137
138 return FIELD_GET(SUN6I_FIFO_STA_TF_CNT_MASK, reg);
139}
140
141static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
142{
143 u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
144
145 reg &= ~mask;
146 sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
147}
148
149static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi)
150{
151 u32 len;
152 u8 byte;
153
154 /* See how much data is available */
155 len = sun6i_spi_get_rx_fifo_count(sspi);
156
157 while (len--) {
158 byte = readb(sspi->base_addr + SUN6I_RXDATA_REG);
159 if (sspi->rx_buf)
160 *sspi->rx_buf++ = byte;
161 }
162}
163
164static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi)
165{
166 u32 cnt;
167 int len;
168 u8 byte;
169
170 /* See how much data we can fit */
171 cnt = sspi->cfg->fifo_depth - sun6i_spi_get_tx_fifo_count(sspi);
172
173 len = min((int)cnt, sspi->len);
174
175 while (len--) {
176 byte = sspi->tx_buf ? *sspi->tx_buf++ : 0;
177 writeb(byte, sspi->base_addr + SUN6I_TXDATA_REG);
178 sspi->len--;
179 }
180}
181
182static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
183{
184 struct sun6i_spi *sspi = spi_controller_get_devdata(spi->controller);
185 u32 reg;
186
187 reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
188 reg &= ~SUN6I_TFR_CTL_CS_MASK;
189 reg |= SUN6I_TFR_CTL_CS(spi_get_chipselect(spi, 0));
190
191 if (enable)
192 reg |= SUN6I_TFR_CTL_CS_LEVEL;
193 else
194 reg &= ~SUN6I_TFR_CTL_CS_LEVEL;
195
196 sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
197}
198
199static size_t sun6i_spi_max_transfer_size(struct spi_device *spi)
200{
201 return SUN6I_MAX_XFER_SIZE - 1;
202}
203
204static void sun6i_spi_dma_rx_cb(void *param)
205{
206 struct sun6i_spi *sspi = param;
207
208 complete(&sspi->dma_rx_done);
209}
210
211static int sun6i_spi_prepare_dma(struct sun6i_spi *sspi,
212 struct spi_transfer *tfr)
213{
214 struct dma_async_tx_descriptor *rxdesc, *txdesc;
215 struct spi_controller *host = sspi->host;
216
217 rxdesc = NULL;
218 if (tfr->rx_buf) {
219 struct dma_slave_config rxconf = {
220 .direction = DMA_DEV_TO_MEM,
221 .src_addr = sspi->dma_addr_rx,
222 .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
223 .src_maxburst = 8,
224 };
225
226 dmaengine_slave_config(host->dma_rx, &rxconf);
227
228 rxdesc = dmaengine_prep_slave_sg(host->dma_rx,
229 tfr->rx_sg.sgl,
230 tfr->rx_sg.nents,
231 DMA_DEV_TO_MEM,
232 DMA_PREP_INTERRUPT);
233 if (!rxdesc)
234 return -EINVAL;
235 rxdesc->callback_param = sspi;
236 rxdesc->callback = sun6i_spi_dma_rx_cb;
237 }
238
239 txdesc = NULL;
240 if (tfr->tx_buf) {
241 struct dma_slave_config txconf = {
242 .direction = DMA_MEM_TO_DEV,
243 .dst_addr = sspi->dma_addr_tx,
244 .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
245 .dst_maxburst = 8,
246 };
247
248 dmaengine_slave_config(host->dma_tx, &txconf);
249
250 txdesc = dmaengine_prep_slave_sg(host->dma_tx,
251 tfr->tx_sg.sgl,
252 tfr->tx_sg.nents,
253 DMA_MEM_TO_DEV,
254 DMA_PREP_INTERRUPT);
255 if (!txdesc) {
256 if (rxdesc)
257 dmaengine_terminate_sync(host->dma_rx);
258 return -EINVAL;
259 }
260 }
261
262 if (tfr->rx_buf) {
263 dmaengine_submit(rxdesc);
264 dma_async_issue_pending(host->dma_rx);
265 }
266
267 if (tfr->tx_buf) {
268 dmaengine_submit(txdesc);
269 dma_async_issue_pending(host->dma_tx);
270 }
271
272 return 0;
273}
274
275static int sun6i_spi_transfer_one(struct spi_controller *host,
276 struct spi_device *spi,
277 struct spi_transfer *tfr)
278{
279 struct sun6i_spi *sspi = spi_controller_get_devdata(host);
280 unsigned int div, div_cdr1, div_cdr2, timeout;
281 unsigned int start, end, tx_time;
282 unsigned int trig_level;
283 unsigned int tx_len = 0, rx_len = 0, nbits = 0;
284 bool use_dma;
285 int ret = 0;
286 u32 reg;
287
288 if (tfr->len > SUN6I_MAX_XFER_SIZE)
289 return -EINVAL;
290
291 reinit_completion(&sspi->done);
292 reinit_completion(&sspi->dma_rx_done);
293 sspi->tx_buf = tfr->tx_buf;
294 sspi->rx_buf = tfr->rx_buf;
295 sspi->len = tfr->len;
296 use_dma = host->can_dma ? host->can_dma(host, spi, tfr) : false;
297
298 /* Clear pending interrupts */
299 sun6i_spi_write(sspi, SUN6I_INT_STA_REG, ~0);
300
301 /* Reset FIFO */
302 sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
303 SUN6I_FIFO_CTL_RF_RST | SUN6I_FIFO_CTL_TF_RST);
304
305 reg = 0;
306
307 if (!use_dma) {
308 /*
309 * Setup FIFO interrupt trigger level
310 * Here we choose 3/4 of the full fifo depth, as it's
311 * the hardcoded value used in old generation of Allwinner
312 * SPI controller. (See spi-sun4i.c)
313 */
314 trig_level = sspi->cfg->fifo_depth / 4 * 3;
315 } else {
316 /*
317 * Setup FIFO DMA request trigger level
318 * We choose 1/2 of the full fifo depth, that value will
319 * be used as DMA burst length.
320 */
321 trig_level = sspi->cfg->fifo_depth / 2;
322
323 if (tfr->tx_buf)
324 reg |= SUN6I_FIFO_CTL_TF_DRQ_EN;
325 if (tfr->rx_buf)
326 reg |= SUN6I_FIFO_CTL_RF_DRQ_EN;
327 }
328
329 reg |= (trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS) |
330 (trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS);
331
332 sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG, reg);
333
334 /*
335 * Setup the transfer control register: Chip Select,
336 * polarities, etc.
337 */
338 reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
339
340 if (spi->mode & SPI_CPOL)
341 reg |= SUN6I_TFR_CTL_CPOL;
342 else
343 reg &= ~SUN6I_TFR_CTL_CPOL;
344
345 if (spi->mode & SPI_CPHA)
346 reg |= SUN6I_TFR_CTL_CPHA;
347 else
348 reg &= ~SUN6I_TFR_CTL_CPHA;
349
350 if (spi->mode & SPI_LSB_FIRST)
351 reg |= SUN6I_TFR_CTL_FBS;
352 else
353 reg &= ~SUN6I_TFR_CTL_FBS;
354
355 /*
356 * If it's a TX only transfer, we don't want to fill the RX
357 * FIFO with bogus data
358 */
359 if (sspi->rx_buf) {
360 reg &= ~SUN6I_TFR_CTL_DHB;
361 rx_len = tfr->len;
362 } else {
363 reg |= SUN6I_TFR_CTL_DHB;
364 }
365
366 /* We want to control the chip select manually */
367 reg |= SUN6I_TFR_CTL_CS_MANUAL;
368
369 sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
370
371 if (sspi->cfg->has_clk_ctl) {
372 unsigned int mclk_rate = clk_get_rate(sspi->mclk);
373
374 /* Ensure that we have a parent clock fast enough */
375 if (mclk_rate < (2 * tfr->speed_hz)) {
376 clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
377 mclk_rate = clk_get_rate(sspi->mclk);
378 }
379
380 /*
381 * Setup clock divider.
382 *
383 * We have two choices there. Either we can use the clock
384 * divide rate 1, which is calculated thanks to this formula:
385 * SPI_CLK = MOD_CLK / (2 ^ cdr)
386 * Or we can use CDR2, which is calculated with the formula:
387 * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
388 * Wether we use the former or the latter is set through the
389 * DRS bit.
390 *
391 * First try CDR2, and if we can't reach the expected
392 * frequency, fall back to CDR1.
393 */
394 div_cdr1 = DIV_ROUND_UP(mclk_rate, tfr->speed_hz);
395 div_cdr2 = DIV_ROUND_UP(div_cdr1, 2);
396 if (div_cdr2 <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
397 reg = SUN6I_CLK_CTL_CDR2(div_cdr2 - 1) | SUN6I_CLK_CTL_DRS;
398 tfr->effective_speed_hz = mclk_rate / (2 * div_cdr2);
399 } else {
400 div = min(SUN6I_CLK_CTL_CDR1_MASK, order_base_2(div_cdr1));
401 reg = SUN6I_CLK_CTL_CDR1(div);
402 tfr->effective_speed_hz = mclk_rate / (1 << div);
403 }
404
405 sun6i_spi_write(sspi, SUN6I_CLK_CTL_REG, reg);
406 } else {
407 clk_set_rate(sspi->mclk, tfr->speed_hz);
408 tfr->effective_speed_hz = clk_get_rate(sspi->mclk);
409
410 /*
411 * Configure work mode.
412 *
413 * There are three work modes depending on the controller clock
414 * frequency:
415 * - normal sample mode : CLK <= 24MHz SDM=1 SDC=0
416 * - delay half-cycle sample mode : CLK <= 40MHz SDM=0 SDC=0
417 * - delay one-cycle sample mode : CLK >= 80MHz SDM=0 SDC=1
418 */
419 reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
420 reg &= ~(SUN6I_TFR_CTL_SDM | SUN6I_TFR_CTL_SDC);
421
422 if (tfr->effective_speed_hz <= 24000000)
423 reg |= SUN6I_TFR_CTL_SDM;
424 else if (tfr->effective_speed_hz >= 80000000)
425 reg |= SUN6I_TFR_CTL_SDC;
426
427 sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
428 }
429
430 /* Finally enable the bus - doing so before might raise SCK to HIGH */
431 reg = sun6i_spi_read(sspi, SUN6I_GBL_CTL_REG);
432 reg |= SUN6I_GBL_CTL_BUS_ENABLE;
433 sun6i_spi_write(sspi, SUN6I_GBL_CTL_REG, reg);
434
435 /* Setup the transfer now... */
436 if (sspi->tx_buf) {
437 tx_len = tfr->len;
438 nbits = tfr->tx_nbits;
439 } else if (tfr->rx_buf) {
440 nbits = tfr->rx_nbits;
441 }
442
443 switch (nbits) {
444 case SPI_NBITS_DUAL:
445 reg = SUN6I_BURST_CTL_CNT_DRM;
446 break;
447 case SPI_NBITS_QUAD:
448 reg = SUN6I_BURST_CTL_CNT_QUAD_EN;
449 break;
450 case SPI_NBITS_SINGLE:
451 default:
452 reg = FIELD_PREP(SUN6I_BURST_CTL_CNT_STC_MASK, tx_len);
453 }
454
455 /* Setup the counters */
456 sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG, reg);
457 sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, tfr->len);
458 sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, tx_len);
459
460 if (!use_dma) {
461 /* Fill the TX FIFO */
462 sun6i_spi_fill_fifo(sspi);
463 } else {
464 ret = sun6i_spi_prepare_dma(sspi, tfr);
465 if (ret) {
466 dev_warn(&host->dev,
467 "%s: prepare DMA failed, ret=%d",
468 dev_name(&spi->dev), ret);
469 return ret;
470 }
471 }
472
473 /* Enable the interrupts */
474 reg = SUN6I_INT_CTL_TC;
475
476 if (!use_dma) {
477 if (rx_len > sspi->cfg->fifo_depth)
478 reg |= SUN6I_INT_CTL_RF_RDY;
479 if (tx_len > sspi->cfg->fifo_depth)
480 reg |= SUN6I_INT_CTL_TF_ERQ;
481 }
482
483 sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
484
485 /* Start the transfer */
486 reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
487 sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg | SUN6I_TFR_CTL_XCH);
488
489 tx_time = spi_controller_xfer_timeout(host, tfr);
490 start = jiffies;
491 timeout = wait_for_completion_timeout(&sspi->done,
492 msecs_to_jiffies(tx_time));
493
494 if (!use_dma) {
495 sun6i_spi_drain_fifo(sspi);
496 } else {
497 if (timeout && rx_len) {
498 /*
499 * Even though RX on the peripheral side has finished
500 * RX DMA might still be in flight
501 */
502 timeout = wait_for_completion_timeout(&sspi->dma_rx_done,
503 timeout);
504 if (!timeout)
505 dev_warn(&host->dev, "RX DMA timeout\n");
506 }
507 }
508
509 end = jiffies;
510 if (!timeout) {
511 dev_warn(&host->dev,
512 "%s: timeout transferring %u bytes@%iHz for %i(%i)ms",
513 dev_name(&spi->dev), tfr->len, tfr->speed_hz,
514 jiffies_to_msecs(end - start), tx_time);
515 ret = -ETIMEDOUT;
516 }
517
518 sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
519
520 if (ret && use_dma) {
521 dmaengine_terminate_sync(host->dma_rx);
522 dmaengine_terminate_sync(host->dma_tx);
523 }
524
525 return ret;
526}
527
528static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
529{
530 struct sun6i_spi *sspi = dev_id;
531 u32 status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG);
532
533 /* Transfer complete */
534 if (status & SUN6I_INT_CTL_TC) {
535 sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TC);
536 complete(&sspi->done);
537 return IRQ_HANDLED;
538 }
539
540 /* Receive FIFO 3/4 full */
541 if (status & SUN6I_INT_CTL_RF_RDY) {
542 sun6i_spi_drain_fifo(sspi);
543 /* Only clear the interrupt _after_ draining the FIFO */
544 sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_RDY);
545 return IRQ_HANDLED;
546 }
547
548 /* Transmit FIFO 3/4 empty */
549 if (status & SUN6I_INT_CTL_TF_ERQ) {
550 sun6i_spi_fill_fifo(sspi);
551
552 if (!sspi->len)
553 /* nothing left to transmit */
554 sun6i_spi_disable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
555
556 /* Only clear the interrupt _after_ re-seeding the FIFO */
557 sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TF_ERQ);
558
559 return IRQ_HANDLED;
560 }
561
562 return IRQ_NONE;
563}
564
565static int sun6i_spi_runtime_resume(struct device *dev)
566{
567 struct spi_controller *host = dev_get_drvdata(dev);
568 struct sun6i_spi *sspi = spi_controller_get_devdata(host);
569 int ret;
570
571 ret = clk_prepare_enable(sspi->hclk);
572 if (ret) {
573 dev_err(dev, "Couldn't enable AHB clock\n");
574 goto out;
575 }
576
577 ret = clk_prepare_enable(sspi->mclk);
578 if (ret) {
579 dev_err(dev, "Couldn't enable module clock\n");
580 goto err;
581 }
582
583 ret = reset_control_deassert(sspi->rstc);
584 if (ret) {
585 dev_err(dev, "Couldn't deassert the device from reset\n");
586 goto err2;
587 }
588
589 sun6i_spi_write(sspi, SUN6I_GBL_CTL_REG,
590 SUN6I_GBL_CTL_MASTER | SUN6I_GBL_CTL_TP);
591
592 return 0;
593
594err2:
595 clk_disable_unprepare(sspi->mclk);
596err:
597 clk_disable_unprepare(sspi->hclk);
598out:
599 return ret;
600}
601
602static int sun6i_spi_runtime_suspend(struct device *dev)
603{
604 struct spi_controller *host = dev_get_drvdata(dev);
605 struct sun6i_spi *sspi = spi_controller_get_devdata(host);
606
607 reset_control_assert(sspi->rstc);
608 clk_disable_unprepare(sspi->mclk);
609 clk_disable_unprepare(sspi->hclk);
610
611 return 0;
612}
613
614static bool sun6i_spi_can_dma(struct spi_controller *host,
615 struct spi_device *spi,
616 struct spi_transfer *xfer)
617{
618 struct sun6i_spi *sspi = spi_controller_get_devdata(host);
619
620 /*
621 * If the number of spi words to transfer is less or equal than
622 * the fifo length we can just fill the fifo and wait for a single
623 * irq, so don't bother setting up dma
624 */
625 return xfer->len > sspi->cfg->fifo_depth;
626}
627
628static int sun6i_spi_probe(struct platform_device *pdev)
629{
630 struct spi_controller *host;
631 struct sun6i_spi *sspi;
632 struct resource *mem;
633 int ret = 0, irq;
634
635 host = spi_alloc_host(&pdev->dev, sizeof(struct sun6i_spi));
636 if (!host) {
637 dev_err(&pdev->dev, "Unable to allocate SPI Host\n");
638 return -ENOMEM;
639 }
640
641 platform_set_drvdata(pdev, host);
642 sspi = spi_controller_get_devdata(host);
643
644 sspi->base_addr = devm_platform_get_and_ioremap_resource(pdev, 0, &mem);
645 if (IS_ERR(sspi->base_addr)) {
646 ret = PTR_ERR(sspi->base_addr);
647 goto err_free_host;
648 }
649
650 irq = platform_get_irq(pdev, 0);
651 if (irq < 0) {
652 ret = -ENXIO;
653 goto err_free_host;
654 }
655
656 ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
657 0, "sun6i-spi", sspi);
658 if (ret) {
659 dev_err(&pdev->dev, "Cannot request IRQ\n");
660 goto err_free_host;
661 }
662
663 sspi->host = host;
664 sspi->cfg = of_device_get_match_data(&pdev->dev);
665
666 host->max_speed_hz = 100 * 1000 * 1000;
667 host->min_speed_hz = 3 * 1000;
668 host->use_gpio_descriptors = true;
669 host->set_cs = sun6i_spi_set_cs;
670 host->transfer_one = sun6i_spi_transfer_one;
671 host->num_chipselect = 4;
672 host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST |
673 sspi->cfg->mode_bits;
674 host->bits_per_word_mask = SPI_BPW_MASK(8);
675 host->dev.of_node = pdev->dev.of_node;
676 host->auto_runtime_pm = true;
677 host->max_transfer_size = sun6i_spi_max_transfer_size;
678
679 sspi->hclk = devm_clk_get(&pdev->dev, "ahb");
680 if (IS_ERR(sspi->hclk)) {
681 dev_err(&pdev->dev, "Unable to acquire AHB clock\n");
682 ret = PTR_ERR(sspi->hclk);
683 goto err_free_host;
684 }
685
686 sspi->mclk = devm_clk_get(&pdev->dev, "mod");
687 if (IS_ERR(sspi->mclk)) {
688 dev_err(&pdev->dev, "Unable to acquire module clock\n");
689 ret = PTR_ERR(sspi->mclk);
690 goto err_free_host;
691 }
692
693 init_completion(&sspi->done);
694 init_completion(&sspi->dma_rx_done);
695
696 sspi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
697 if (IS_ERR(sspi->rstc)) {
698 dev_err(&pdev->dev, "Couldn't get reset controller\n");
699 ret = PTR_ERR(sspi->rstc);
700 goto err_free_host;
701 }
702
703 host->dma_tx = dma_request_chan(&pdev->dev, "tx");
704 if (IS_ERR(host->dma_tx)) {
705 /* Check tx to see if we need defer probing driver */
706 if (PTR_ERR(host->dma_tx) == -EPROBE_DEFER) {
707 ret = -EPROBE_DEFER;
708 goto err_free_host;
709 }
710 dev_warn(&pdev->dev, "Failed to request TX DMA channel\n");
711 host->dma_tx = NULL;
712 }
713
714 host->dma_rx = dma_request_chan(&pdev->dev, "rx");
715 if (IS_ERR(host->dma_rx)) {
716 if (PTR_ERR(host->dma_rx) == -EPROBE_DEFER) {
717 ret = -EPROBE_DEFER;
718 goto err_free_dma_tx;
719 }
720 dev_warn(&pdev->dev, "Failed to request RX DMA channel\n");
721 host->dma_rx = NULL;
722 }
723
724 if (host->dma_tx && host->dma_rx) {
725 sspi->dma_addr_tx = mem->start + SUN6I_TXDATA_REG;
726 sspi->dma_addr_rx = mem->start + SUN6I_RXDATA_REG;
727 host->can_dma = sun6i_spi_can_dma;
728 }
729
730 /*
731 * This wake-up/shutdown pattern is to be able to have the
732 * device woken up, even if runtime_pm is disabled
733 */
734 ret = sun6i_spi_runtime_resume(&pdev->dev);
735 if (ret) {
736 dev_err(&pdev->dev, "Couldn't resume the device\n");
737 goto err_free_dma_rx;
738 }
739
740 pm_runtime_set_autosuspend_delay(&pdev->dev, SUN6I_AUTOSUSPEND_TIMEOUT);
741 pm_runtime_use_autosuspend(&pdev->dev);
742 pm_runtime_set_active(&pdev->dev);
743 pm_runtime_enable(&pdev->dev);
744
745 ret = devm_spi_register_controller(&pdev->dev, host);
746 if (ret) {
747 dev_err(&pdev->dev, "cannot register SPI host\n");
748 goto err_pm_disable;
749 }
750
751 return 0;
752
753err_pm_disable:
754 pm_runtime_disable(&pdev->dev);
755 sun6i_spi_runtime_suspend(&pdev->dev);
756err_free_dma_rx:
757 if (host->dma_rx)
758 dma_release_channel(host->dma_rx);
759err_free_dma_tx:
760 if (host->dma_tx)
761 dma_release_channel(host->dma_tx);
762err_free_host:
763 spi_controller_put(host);
764 return ret;
765}
766
767static void sun6i_spi_remove(struct platform_device *pdev)
768{
769 struct spi_controller *host = platform_get_drvdata(pdev);
770
771 pm_runtime_force_suspend(&pdev->dev);
772
773 if (host->dma_tx)
774 dma_release_channel(host->dma_tx);
775 if (host->dma_rx)
776 dma_release_channel(host->dma_rx);
777}
778
779static const struct sun6i_spi_cfg sun6i_a31_spi_cfg = {
780 .fifo_depth = SUN6I_FIFO_DEPTH,
781 .has_clk_ctl = true,
782};
783
784static const struct sun6i_spi_cfg sun8i_h3_spi_cfg = {
785 .fifo_depth = SUN8I_FIFO_DEPTH,
786 .has_clk_ctl = true,
787};
788
789static const struct sun6i_spi_cfg sun50i_r329_spi_cfg = {
790 .fifo_depth = SUN8I_FIFO_DEPTH,
791 .mode_bits = SPI_RX_DUAL | SPI_TX_DUAL | SPI_RX_QUAD | SPI_TX_QUAD,
792};
793
794static const struct of_device_id sun6i_spi_match[] = {
795 { .compatible = "allwinner,sun6i-a31-spi", .data = &sun6i_a31_spi_cfg },
796 { .compatible = "allwinner,sun8i-h3-spi", .data = &sun8i_h3_spi_cfg },
797 {
798 .compatible = "allwinner,sun50i-r329-spi",
799 .data = &sun50i_r329_spi_cfg
800 },
801 {}
802};
803MODULE_DEVICE_TABLE(of, sun6i_spi_match);
804
805static const struct dev_pm_ops sun6i_spi_pm_ops = {
806 .runtime_resume = sun6i_spi_runtime_resume,
807 .runtime_suspend = sun6i_spi_runtime_suspend,
808};
809
810static struct platform_driver sun6i_spi_driver = {
811 .probe = sun6i_spi_probe,
812 .remove_new = sun6i_spi_remove,
813 .driver = {
814 .name = "sun6i-spi",
815 .of_match_table = sun6i_spi_match,
816 .pm = &sun6i_spi_pm_ops,
817 },
818};
819module_platform_driver(sun6i_spi_driver);
820
821MODULE_AUTHOR("Pan Nan <pannan@allwinnertech.com>");
822MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
823MODULE_DESCRIPTION("Allwinner A31 SPI controller driver");
824MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2012 - 2014 Allwinner Tech
4 * Pan Nan <pannan@allwinnertech.com>
5 *
6 * Copyright (C) 2014 Maxime Ripard
7 * Maxime Ripard <maxime.ripard@free-electrons.com>
8 */
9
10#include <linux/clk.h>
11#include <linux/delay.h>
12#include <linux/device.h>
13#include <linux/interrupt.h>
14#include <linux/io.h>
15#include <linux/module.h>
16#include <linux/of_device.h>
17#include <linux/platform_device.h>
18#include <linux/pm_runtime.h>
19#include <linux/reset.h>
20
21#include <linux/spi/spi.h>
22
23#define SUN6I_FIFO_DEPTH 128
24#define SUN8I_FIFO_DEPTH 64
25
26#define SUN6I_GBL_CTL_REG 0x04
27#define SUN6I_GBL_CTL_BUS_ENABLE BIT(0)
28#define SUN6I_GBL_CTL_MASTER BIT(1)
29#define SUN6I_GBL_CTL_TP BIT(7)
30#define SUN6I_GBL_CTL_RST BIT(31)
31
32#define SUN6I_TFR_CTL_REG 0x08
33#define SUN6I_TFR_CTL_CPHA BIT(0)
34#define SUN6I_TFR_CTL_CPOL BIT(1)
35#define SUN6I_TFR_CTL_SPOL BIT(2)
36#define SUN6I_TFR_CTL_CS_MASK 0x30
37#define SUN6I_TFR_CTL_CS(cs) (((cs) << 4) & SUN6I_TFR_CTL_CS_MASK)
38#define SUN6I_TFR_CTL_CS_MANUAL BIT(6)
39#define SUN6I_TFR_CTL_CS_LEVEL BIT(7)
40#define SUN6I_TFR_CTL_DHB BIT(8)
41#define SUN6I_TFR_CTL_FBS BIT(12)
42#define SUN6I_TFR_CTL_XCH BIT(31)
43
44#define SUN6I_INT_CTL_REG 0x10
45#define SUN6I_INT_CTL_RF_RDY BIT(0)
46#define SUN6I_INT_CTL_TF_ERQ BIT(4)
47#define SUN6I_INT_CTL_RF_OVF BIT(8)
48#define SUN6I_INT_CTL_TC BIT(12)
49
50#define SUN6I_INT_STA_REG 0x14
51
52#define SUN6I_FIFO_CTL_REG 0x18
53#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_MASK 0xff
54#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS 0
55#define SUN6I_FIFO_CTL_RF_RST BIT(15)
56#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_MASK 0xff
57#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS 16
58#define SUN6I_FIFO_CTL_TF_RST BIT(31)
59
60#define SUN6I_FIFO_STA_REG 0x1c
61#define SUN6I_FIFO_STA_RF_CNT_MASK 0x7f
62#define SUN6I_FIFO_STA_RF_CNT_BITS 0
63#define SUN6I_FIFO_STA_TF_CNT_MASK 0x7f
64#define SUN6I_FIFO_STA_TF_CNT_BITS 16
65
66#define SUN6I_CLK_CTL_REG 0x24
67#define SUN6I_CLK_CTL_CDR2_MASK 0xff
68#define SUN6I_CLK_CTL_CDR2(div) (((div) & SUN6I_CLK_CTL_CDR2_MASK) << 0)
69#define SUN6I_CLK_CTL_CDR1_MASK 0xf
70#define SUN6I_CLK_CTL_CDR1(div) (((div) & SUN6I_CLK_CTL_CDR1_MASK) << 8)
71#define SUN6I_CLK_CTL_DRS BIT(12)
72
73#define SUN6I_MAX_XFER_SIZE 0xffffff
74
75#define SUN6I_BURST_CNT_REG 0x30
76#define SUN6I_BURST_CNT(cnt) ((cnt) & SUN6I_MAX_XFER_SIZE)
77
78#define SUN6I_XMIT_CNT_REG 0x34
79#define SUN6I_XMIT_CNT(cnt) ((cnt) & SUN6I_MAX_XFER_SIZE)
80
81#define SUN6I_BURST_CTL_CNT_REG 0x38
82#define SUN6I_BURST_CTL_CNT_STC(cnt) ((cnt) & SUN6I_MAX_XFER_SIZE)
83
84#define SUN6I_TXDATA_REG 0x200
85#define SUN6I_RXDATA_REG 0x300
86
87struct sun6i_spi {
88 struct spi_master *master;
89 void __iomem *base_addr;
90 struct clk *hclk;
91 struct clk *mclk;
92 struct reset_control *rstc;
93
94 struct completion done;
95
96 const u8 *tx_buf;
97 u8 *rx_buf;
98 int len;
99 unsigned long fifo_depth;
100};
101
102static inline u32 sun6i_spi_read(struct sun6i_spi *sspi, u32 reg)
103{
104 return readl(sspi->base_addr + reg);
105}
106
107static inline void sun6i_spi_write(struct sun6i_spi *sspi, u32 reg, u32 value)
108{
109 writel(value, sspi->base_addr + reg);
110}
111
112static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
113{
114 u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
115
116 reg >>= SUN6I_FIFO_STA_TF_CNT_BITS;
117
118 return reg & SUN6I_FIFO_STA_TF_CNT_MASK;
119}
120
121static inline void sun6i_spi_enable_interrupt(struct sun6i_spi *sspi, u32 mask)
122{
123 u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
124
125 reg |= mask;
126 sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
127}
128
129static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
130{
131 u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
132
133 reg &= ~mask;
134 sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
135}
136
137static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi, int len)
138{
139 u32 reg, cnt;
140 u8 byte;
141
142 /* See how much data is available */
143 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
144 reg &= SUN6I_FIFO_STA_RF_CNT_MASK;
145 cnt = reg >> SUN6I_FIFO_STA_RF_CNT_BITS;
146
147 if (len > cnt)
148 len = cnt;
149
150 while (len--) {
151 byte = readb(sspi->base_addr + SUN6I_RXDATA_REG);
152 if (sspi->rx_buf)
153 *sspi->rx_buf++ = byte;
154 }
155}
156
157static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi, int len)
158{
159 u32 cnt;
160 u8 byte;
161
162 /* See how much data we can fit */
163 cnt = sspi->fifo_depth - sun6i_spi_get_tx_fifo_count(sspi);
164
165 len = min3(len, (int)cnt, sspi->len);
166
167 while (len--) {
168 byte = sspi->tx_buf ? *sspi->tx_buf++ : 0;
169 writeb(byte, sspi->base_addr + SUN6I_TXDATA_REG);
170 sspi->len--;
171 }
172}
173
174static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
175{
176 struct sun6i_spi *sspi = spi_master_get_devdata(spi->master);
177 u32 reg;
178
179 reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
180 reg &= ~SUN6I_TFR_CTL_CS_MASK;
181 reg |= SUN6I_TFR_CTL_CS(spi->chip_select);
182
183 if (enable)
184 reg |= SUN6I_TFR_CTL_CS_LEVEL;
185 else
186 reg &= ~SUN6I_TFR_CTL_CS_LEVEL;
187
188 sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
189}
190
191static size_t sun6i_spi_max_transfer_size(struct spi_device *spi)
192{
193 return SUN6I_MAX_XFER_SIZE - 1;
194}
195
196static int sun6i_spi_transfer_one(struct spi_master *master,
197 struct spi_device *spi,
198 struct spi_transfer *tfr)
199{
200 struct sun6i_spi *sspi = spi_master_get_devdata(master);
201 unsigned int mclk_rate, div, timeout;
202 unsigned int start, end, tx_time;
203 unsigned int trig_level;
204 unsigned int tx_len = 0;
205 int ret = 0;
206 u32 reg;
207
208 if (tfr->len > SUN6I_MAX_XFER_SIZE)
209 return -EINVAL;
210
211 reinit_completion(&sspi->done);
212 sspi->tx_buf = tfr->tx_buf;
213 sspi->rx_buf = tfr->rx_buf;
214 sspi->len = tfr->len;
215
216 /* Clear pending interrupts */
217 sun6i_spi_write(sspi, SUN6I_INT_STA_REG, ~0);
218
219 /* Reset FIFO */
220 sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
221 SUN6I_FIFO_CTL_RF_RST | SUN6I_FIFO_CTL_TF_RST);
222
223 /*
224 * Setup FIFO interrupt trigger level
225 * Here we choose 3/4 of the full fifo depth, as it's the hardcoded
226 * value used in old generation of Allwinner SPI controller.
227 * (See spi-sun4i.c)
228 */
229 trig_level = sspi->fifo_depth / 4 * 3;
230 sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
231 (trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS) |
232 (trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS));
233
234 /*
235 * Setup the transfer control register: Chip Select,
236 * polarities, etc.
237 */
238 reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
239
240 if (spi->mode & SPI_CPOL)
241 reg |= SUN6I_TFR_CTL_CPOL;
242 else
243 reg &= ~SUN6I_TFR_CTL_CPOL;
244
245 if (spi->mode & SPI_CPHA)
246 reg |= SUN6I_TFR_CTL_CPHA;
247 else
248 reg &= ~SUN6I_TFR_CTL_CPHA;
249
250 if (spi->mode & SPI_LSB_FIRST)
251 reg |= SUN6I_TFR_CTL_FBS;
252 else
253 reg &= ~SUN6I_TFR_CTL_FBS;
254
255 /*
256 * If it's a TX only transfer, we don't want to fill the RX
257 * FIFO with bogus data
258 */
259 if (sspi->rx_buf)
260 reg &= ~SUN6I_TFR_CTL_DHB;
261 else
262 reg |= SUN6I_TFR_CTL_DHB;
263
264 /* We want to control the chip select manually */
265 reg |= SUN6I_TFR_CTL_CS_MANUAL;
266
267 sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
268
269 /* Ensure that we have a parent clock fast enough */
270 mclk_rate = clk_get_rate(sspi->mclk);
271 if (mclk_rate < (2 * tfr->speed_hz)) {
272 clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
273 mclk_rate = clk_get_rate(sspi->mclk);
274 }
275
276 /*
277 * Setup clock divider.
278 *
279 * We have two choices there. Either we can use the clock
280 * divide rate 1, which is calculated thanks to this formula:
281 * SPI_CLK = MOD_CLK / (2 ^ cdr)
282 * Or we can use CDR2, which is calculated with the formula:
283 * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
284 * Wether we use the former or the latter is set through the
285 * DRS bit.
286 *
287 * First try CDR2, and if we can't reach the expected
288 * frequency, fall back to CDR1.
289 */
290 div = mclk_rate / (2 * tfr->speed_hz);
291 if (div <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
292 if (div > 0)
293 div--;
294
295 reg = SUN6I_CLK_CTL_CDR2(div) | SUN6I_CLK_CTL_DRS;
296 } else {
297 div = ilog2(mclk_rate) - ilog2(tfr->speed_hz);
298 reg = SUN6I_CLK_CTL_CDR1(div);
299 }
300
301 sun6i_spi_write(sspi, SUN6I_CLK_CTL_REG, reg);
302
303 /* Setup the transfer now... */
304 if (sspi->tx_buf)
305 tx_len = tfr->len;
306
307 /* Setup the counters */
308 sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, SUN6I_BURST_CNT(tfr->len));
309 sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, SUN6I_XMIT_CNT(tx_len));
310 sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG,
311 SUN6I_BURST_CTL_CNT_STC(tx_len));
312
313 /* Fill the TX FIFO */
314 sun6i_spi_fill_fifo(sspi, sspi->fifo_depth);
315
316 /* Enable the interrupts */
317 sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
318 sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC |
319 SUN6I_INT_CTL_RF_RDY);
320 if (tx_len > sspi->fifo_depth)
321 sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
322
323 /* Start the transfer */
324 reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
325 sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg | SUN6I_TFR_CTL_XCH);
326
327 tx_time = max(tfr->len * 8 * 2 / (tfr->speed_hz / 1000), 100U);
328 start = jiffies;
329 timeout = wait_for_completion_timeout(&sspi->done,
330 msecs_to_jiffies(tx_time));
331 end = jiffies;
332 if (!timeout) {
333 dev_warn(&master->dev,
334 "%s: timeout transferring %u bytes@%iHz for %i(%i)ms",
335 dev_name(&spi->dev), tfr->len, tfr->speed_hz,
336 jiffies_to_msecs(end - start), tx_time);
337 ret = -ETIMEDOUT;
338 goto out;
339 }
340
341out:
342 sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
343
344 return ret;
345}
346
347static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
348{
349 struct sun6i_spi *sspi = dev_id;
350 u32 status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG);
351
352 /* Transfer complete */
353 if (status & SUN6I_INT_CTL_TC) {
354 sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TC);
355 sun6i_spi_drain_fifo(sspi, sspi->fifo_depth);
356 complete(&sspi->done);
357 return IRQ_HANDLED;
358 }
359
360 /* Receive FIFO 3/4 full */
361 if (status & SUN6I_INT_CTL_RF_RDY) {
362 sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH);
363 /* Only clear the interrupt _after_ draining the FIFO */
364 sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_RDY);
365 return IRQ_HANDLED;
366 }
367
368 /* Transmit FIFO 3/4 empty */
369 if (status & SUN6I_INT_CTL_TF_ERQ) {
370 sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH);
371
372 if (!sspi->len)
373 /* nothing left to transmit */
374 sun6i_spi_disable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
375
376 /* Only clear the interrupt _after_ re-seeding the FIFO */
377 sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TF_ERQ);
378
379 return IRQ_HANDLED;
380 }
381
382 return IRQ_NONE;
383}
384
385static int sun6i_spi_runtime_resume(struct device *dev)
386{
387 struct spi_master *master = dev_get_drvdata(dev);
388 struct sun6i_spi *sspi = spi_master_get_devdata(master);
389 int ret;
390
391 ret = clk_prepare_enable(sspi->hclk);
392 if (ret) {
393 dev_err(dev, "Couldn't enable AHB clock\n");
394 goto out;
395 }
396
397 ret = clk_prepare_enable(sspi->mclk);
398 if (ret) {
399 dev_err(dev, "Couldn't enable module clock\n");
400 goto err;
401 }
402
403 ret = reset_control_deassert(sspi->rstc);
404 if (ret) {
405 dev_err(dev, "Couldn't deassert the device from reset\n");
406 goto err2;
407 }
408
409 sun6i_spi_write(sspi, SUN6I_GBL_CTL_REG,
410 SUN6I_GBL_CTL_BUS_ENABLE | SUN6I_GBL_CTL_MASTER | SUN6I_GBL_CTL_TP);
411
412 return 0;
413
414err2:
415 clk_disable_unprepare(sspi->mclk);
416err:
417 clk_disable_unprepare(sspi->hclk);
418out:
419 return ret;
420}
421
422static int sun6i_spi_runtime_suspend(struct device *dev)
423{
424 struct spi_master *master = dev_get_drvdata(dev);
425 struct sun6i_spi *sspi = spi_master_get_devdata(master);
426
427 reset_control_assert(sspi->rstc);
428 clk_disable_unprepare(sspi->mclk);
429 clk_disable_unprepare(sspi->hclk);
430
431 return 0;
432}
433
434static int sun6i_spi_probe(struct platform_device *pdev)
435{
436 struct spi_master *master;
437 struct sun6i_spi *sspi;
438 int ret = 0, irq;
439
440 master = spi_alloc_master(&pdev->dev, sizeof(struct sun6i_spi));
441 if (!master) {
442 dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
443 return -ENOMEM;
444 }
445
446 platform_set_drvdata(pdev, master);
447 sspi = spi_master_get_devdata(master);
448
449 sspi->base_addr = devm_platform_ioremap_resource(pdev, 0);
450 if (IS_ERR(sspi->base_addr)) {
451 ret = PTR_ERR(sspi->base_addr);
452 goto err_free_master;
453 }
454
455 irq = platform_get_irq(pdev, 0);
456 if (irq < 0) {
457 ret = -ENXIO;
458 goto err_free_master;
459 }
460
461 ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
462 0, "sun6i-spi", sspi);
463 if (ret) {
464 dev_err(&pdev->dev, "Cannot request IRQ\n");
465 goto err_free_master;
466 }
467
468 sspi->master = master;
469 sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);
470
471 master->max_speed_hz = 100 * 1000 * 1000;
472 master->min_speed_hz = 3 * 1000;
473 master->set_cs = sun6i_spi_set_cs;
474 master->transfer_one = sun6i_spi_transfer_one;
475 master->num_chipselect = 4;
476 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
477 master->bits_per_word_mask = SPI_BPW_MASK(8);
478 master->dev.of_node = pdev->dev.of_node;
479 master->auto_runtime_pm = true;
480 master->max_transfer_size = sun6i_spi_max_transfer_size;
481
482 sspi->hclk = devm_clk_get(&pdev->dev, "ahb");
483 if (IS_ERR(sspi->hclk)) {
484 dev_err(&pdev->dev, "Unable to acquire AHB clock\n");
485 ret = PTR_ERR(sspi->hclk);
486 goto err_free_master;
487 }
488
489 sspi->mclk = devm_clk_get(&pdev->dev, "mod");
490 if (IS_ERR(sspi->mclk)) {
491 dev_err(&pdev->dev, "Unable to acquire module clock\n");
492 ret = PTR_ERR(sspi->mclk);
493 goto err_free_master;
494 }
495
496 init_completion(&sspi->done);
497
498 sspi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
499 if (IS_ERR(sspi->rstc)) {
500 dev_err(&pdev->dev, "Couldn't get reset controller\n");
501 ret = PTR_ERR(sspi->rstc);
502 goto err_free_master;
503 }
504
505 /*
506 * This wake-up/shutdown pattern is to be able to have the
507 * device woken up, even if runtime_pm is disabled
508 */
509 ret = sun6i_spi_runtime_resume(&pdev->dev);
510 if (ret) {
511 dev_err(&pdev->dev, "Couldn't resume the device\n");
512 goto err_free_master;
513 }
514
515 pm_runtime_set_active(&pdev->dev);
516 pm_runtime_enable(&pdev->dev);
517 pm_runtime_idle(&pdev->dev);
518
519 ret = devm_spi_register_master(&pdev->dev, master);
520 if (ret) {
521 dev_err(&pdev->dev, "cannot register SPI master\n");
522 goto err_pm_disable;
523 }
524
525 return 0;
526
527err_pm_disable:
528 pm_runtime_disable(&pdev->dev);
529 sun6i_spi_runtime_suspend(&pdev->dev);
530err_free_master:
531 spi_master_put(master);
532 return ret;
533}
534
535static int sun6i_spi_remove(struct platform_device *pdev)
536{
537 pm_runtime_force_suspend(&pdev->dev);
538
539 return 0;
540}
541
542static const struct of_device_id sun6i_spi_match[] = {
543 { .compatible = "allwinner,sun6i-a31-spi", .data = (void *)SUN6I_FIFO_DEPTH },
544 { .compatible = "allwinner,sun8i-h3-spi", .data = (void *)SUN8I_FIFO_DEPTH },
545 {}
546};
547MODULE_DEVICE_TABLE(of, sun6i_spi_match);
548
549static const struct dev_pm_ops sun6i_spi_pm_ops = {
550 .runtime_resume = sun6i_spi_runtime_resume,
551 .runtime_suspend = sun6i_spi_runtime_suspend,
552};
553
554static struct platform_driver sun6i_spi_driver = {
555 .probe = sun6i_spi_probe,
556 .remove = sun6i_spi_remove,
557 .driver = {
558 .name = "sun6i-spi",
559 .of_match_table = sun6i_spi_match,
560 .pm = &sun6i_spi_pm_ops,
561 },
562};
563module_platform_driver(sun6i_spi_driver);
564
565MODULE_AUTHOR("Pan Nan <pannan@allwinnertech.com>");
566MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
567MODULE_DESCRIPTION("Allwinner A31 SPI controller driver");
568MODULE_LICENSE("GPL");