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Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[deliverable/linux.git] / drivers / spi / spi-atmel.c
1 /*
2 * Driver for Atmel AT32 and AT91 SPI Controllers
3 *
4 * Copyright (C) 2006 Atmel Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/clk.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/delay.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/dmaengine.h>
18 #include <linux/err.h>
19 #include <linux/interrupt.h>
20 #include <linux/spi/spi.h>
21 #include <linux/slab.h>
22 #include <linux/platform_data/dma-atmel.h>
23 #include <linux/of.h>
24
25 #include <linux/io.h>
26 #include <linux/gpio.h>
27 #include <linux/pinctrl/consumer.h>
28 #include <linux/pm_runtime.h>
29
30 /* SPI register offsets */
31 #define SPI_CR 0x0000
32 #define SPI_MR 0x0004
33 #define SPI_RDR 0x0008
34 #define SPI_TDR 0x000c
35 #define SPI_SR 0x0010
36 #define SPI_IER 0x0014
37 #define SPI_IDR 0x0018
38 #define SPI_IMR 0x001c
39 #define SPI_CSR0 0x0030
40 #define SPI_CSR1 0x0034
41 #define SPI_CSR2 0x0038
42 #define SPI_CSR3 0x003c
43 #define SPI_FMR 0x0040
44 #define SPI_FLR 0x0044
45 #define SPI_VERSION 0x00fc
46 #define SPI_RPR 0x0100
47 #define SPI_RCR 0x0104
48 #define SPI_TPR 0x0108
49 #define SPI_TCR 0x010c
50 #define SPI_RNPR 0x0110
51 #define SPI_RNCR 0x0114
52 #define SPI_TNPR 0x0118
53 #define SPI_TNCR 0x011c
54 #define SPI_PTCR 0x0120
55 #define SPI_PTSR 0x0124
56
57 /* Bitfields in CR */
58 #define SPI_SPIEN_OFFSET 0
59 #define SPI_SPIEN_SIZE 1
60 #define SPI_SPIDIS_OFFSET 1
61 #define SPI_SPIDIS_SIZE 1
62 #define SPI_SWRST_OFFSET 7
63 #define SPI_SWRST_SIZE 1
64 #define SPI_LASTXFER_OFFSET 24
65 #define SPI_LASTXFER_SIZE 1
66 #define SPI_TXFCLR_OFFSET 16
67 #define SPI_TXFCLR_SIZE 1
68 #define SPI_RXFCLR_OFFSET 17
69 #define SPI_RXFCLR_SIZE 1
70 #define SPI_FIFOEN_OFFSET 30
71 #define SPI_FIFOEN_SIZE 1
72 #define SPI_FIFODIS_OFFSET 31
73 #define SPI_FIFODIS_SIZE 1
74
75 /* Bitfields in MR */
76 #define SPI_MSTR_OFFSET 0
77 #define SPI_MSTR_SIZE 1
78 #define SPI_PS_OFFSET 1
79 #define SPI_PS_SIZE 1
80 #define SPI_PCSDEC_OFFSET 2
81 #define SPI_PCSDEC_SIZE 1
82 #define SPI_FDIV_OFFSET 3
83 #define SPI_FDIV_SIZE 1
84 #define SPI_MODFDIS_OFFSET 4
85 #define SPI_MODFDIS_SIZE 1
86 #define SPI_WDRBT_OFFSET 5
87 #define SPI_WDRBT_SIZE 1
88 #define SPI_LLB_OFFSET 7
89 #define SPI_LLB_SIZE 1
90 #define SPI_PCS_OFFSET 16
91 #define SPI_PCS_SIZE 4
92 #define SPI_DLYBCS_OFFSET 24
93 #define SPI_DLYBCS_SIZE 8
94
95 /* Bitfields in RDR */
96 #define SPI_RD_OFFSET 0
97 #define SPI_RD_SIZE 16
98
99 /* Bitfields in TDR */
100 #define SPI_TD_OFFSET 0
101 #define SPI_TD_SIZE 16
102
103 /* Bitfields in SR */
104 #define SPI_RDRF_OFFSET 0
105 #define SPI_RDRF_SIZE 1
106 #define SPI_TDRE_OFFSET 1
107 #define SPI_TDRE_SIZE 1
108 #define SPI_MODF_OFFSET 2
109 #define SPI_MODF_SIZE 1
110 #define SPI_OVRES_OFFSET 3
111 #define SPI_OVRES_SIZE 1
112 #define SPI_ENDRX_OFFSET 4
113 #define SPI_ENDRX_SIZE 1
114 #define SPI_ENDTX_OFFSET 5
115 #define SPI_ENDTX_SIZE 1
116 #define SPI_RXBUFF_OFFSET 6
117 #define SPI_RXBUFF_SIZE 1
118 #define SPI_TXBUFE_OFFSET 7
119 #define SPI_TXBUFE_SIZE 1
120 #define SPI_NSSR_OFFSET 8
121 #define SPI_NSSR_SIZE 1
122 #define SPI_TXEMPTY_OFFSET 9
123 #define SPI_TXEMPTY_SIZE 1
124 #define SPI_SPIENS_OFFSET 16
125 #define SPI_SPIENS_SIZE 1
126 #define SPI_TXFEF_OFFSET 24
127 #define SPI_TXFEF_SIZE 1
128 #define SPI_TXFFF_OFFSET 25
129 #define SPI_TXFFF_SIZE 1
130 #define SPI_TXFTHF_OFFSET 26
131 #define SPI_TXFTHF_SIZE 1
132 #define SPI_RXFEF_OFFSET 27
133 #define SPI_RXFEF_SIZE 1
134 #define SPI_RXFFF_OFFSET 28
135 #define SPI_RXFFF_SIZE 1
136 #define SPI_RXFTHF_OFFSET 29
137 #define SPI_RXFTHF_SIZE 1
138 #define SPI_TXFPTEF_OFFSET 30
139 #define SPI_TXFPTEF_SIZE 1
140 #define SPI_RXFPTEF_OFFSET 31
141 #define SPI_RXFPTEF_SIZE 1
142
143 /* Bitfields in CSR0 */
144 #define SPI_CPOL_OFFSET 0
145 #define SPI_CPOL_SIZE 1
146 #define SPI_NCPHA_OFFSET 1
147 #define SPI_NCPHA_SIZE 1
148 #define SPI_CSAAT_OFFSET 3
149 #define SPI_CSAAT_SIZE 1
150 #define SPI_BITS_OFFSET 4
151 #define SPI_BITS_SIZE 4
152 #define SPI_SCBR_OFFSET 8
153 #define SPI_SCBR_SIZE 8
154 #define SPI_DLYBS_OFFSET 16
155 #define SPI_DLYBS_SIZE 8
156 #define SPI_DLYBCT_OFFSET 24
157 #define SPI_DLYBCT_SIZE 8
158
159 /* Bitfields in RCR */
160 #define SPI_RXCTR_OFFSET 0
161 #define SPI_RXCTR_SIZE 16
162
163 /* Bitfields in TCR */
164 #define SPI_TXCTR_OFFSET 0
165 #define SPI_TXCTR_SIZE 16
166
167 /* Bitfields in RNCR */
168 #define SPI_RXNCR_OFFSET 0
169 #define SPI_RXNCR_SIZE 16
170
171 /* Bitfields in TNCR */
172 #define SPI_TXNCR_OFFSET 0
173 #define SPI_TXNCR_SIZE 16
174
175 /* Bitfields in PTCR */
176 #define SPI_RXTEN_OFFSET 0
177 #define SPI_RXTEN_SIZE 1
178 #define SPI_RXTDIS_OFFSET 1
179 #define SPI_RXTDIS_SIZE 1
180 #define SPI_TXTEN_OFFSET 8
181 #define SPI_TXTEN_SIZE 1
182 #define SPI_TXTDIS_OFFSET 9
183 #define SPI_TXTDIS_SIZE 1
184
185 /* Bitfields in FMR */
186 #define SPI_TXRDYM_OFFSET 0
187 #define SPI_TXRDYM_SIZE 2
188 #define SPI_RXRDYM_OFFSET 4
189 #define SPI_RXRDYM_SIZE 2
190 #define SPI_TXFTHRES_OFFSET 16
191 #define SPI_TXFTHRES_SIZE 6
192 #define SPI_RXFTHRES_OFFSET 24
193 #define SPI_RXFTHRES_SIZE 6
194
195 /* Bitfields in FLR */
196 #define SPI_TXFL_OFFSET 0
197 #define SPI_TXFL_SIZE 6
198 #define SPI_RXFL_OFFSET 16
199 #define SPI_RXFL_SIZE 6
200
201 /* Constants for BITS */
202 #define SPI_BITS_8_BPT 0
203 #define SPI_BITS_9_BPT 1
204 #define SPI_BITS_10_BPT 2
205 #define SPI_BITS_11_BPT 3
206 #define SPI_BITS_12_BPT 4
207 #define SPI_BITS_13_BPT 5
208 #define SPI_BITS_14_BPT 6
209 #define SPI_BITS_15_BPT 7
210 #define SPI_BITS_16_BPT 8
211 #define SPI_ONE_DATA 0
212 #define SPI_TWO_DATA 1
213 #define SPI_FOUR_DATA 2
214
215 /* Bit manipulation macros */
216 #define SPI_BIT(name) \
217 (1 << SPI_##name##_OFFSET)
218 #define SPI_BF(name, value) \
219 (((value) & ((1 << SPI_##name##_SIZE) - 1)) << SPI_##name##_OFFSET)
220 #define SPI_BFEXT(name, value) \
221 (((value) >> SPI_##name##_OFFSET) & ((1 << SPI_##name##_SIZE) - 1))
222 #define SPI_BFINS(name, value, old) \
223 (((old) & ~(((1 << SPI_##name##_SIZE) - 1) << SPI_##name##_OFFSET)) \
224 | SPI_BF(name, value))
225
226 /* Register access macros */
227 #ifdef CONFIG_AVR32
228 #define spi_readl(port, reg) \
229 __raw_readl((port)->regs + SPI_##reg)
230 #define spi_writel(port, reg, value) \
231 __raw_writel((value), (port)->regs + SPI_##reg)
232
233 #define spi_readw(port, reg) \
234 __raw_readw((port)->regs + SPI_##reg)
235 #define spi_writew(port, reg, value) \
236 __raw_writew((value), (port)->regs + SPI_##reg)
237
238 #define spi_readb(port, reg) \
239 __raw_readb((port)->regs + SPI_##reg)
240 #define spi_writeb(port, reg, value) \
241 __raw_writeb((value), (port)->regs + SPI_##reg)
242 #else
243 #define spi_readl(port, reg) \
244 readl_relaxed((port)->regs + SPI_##reg)
245 #define spi_writel(port, reg, value) \
246 writel_relaxed((value), (port)->regs + SPI_##reg)
247
248 #define spi_readw(port, reg) \
249 readw_relaxed((port)->regs + SPI_##reg)
250 #define spi_writew(port, reg, value) \
251 writew_relaxed((value), (port)->regs + SPI_##reg)
252
253 #define spi_readb(port, reg) \
254 readb_relaxed((port)->regs + SPI_##reg)
255 #define spi_writeb(port, reg, value) \
256 writeb_relaxed((value), (port)->regs + SPI_##reg)
257 #endif
258 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
259 * cache operations; better heuristics consider wordsize and bitrate.
260 */
261 #define DMA_MIN_BYTES 16
262
263 #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
264
265 #define AUTOSUSPEND_TIMEOUT 2000
266
267 struct atmel_spi_dma {
268 struct dma_chan *chan_rx;
269 struct dma_chan *chan_tx;
270 struct scatterlist sgrx;
271 struct scatterlist sgtx;
272 struct dma_async_tx_descriptor *data_desc_rx;
273 struct dma_async_tx_descriptor *data_desc_tx;
274
275 struct at_dma_slave dma_slave;
276 };
277
278 struct atmel_spi_caps {
279 bool is_spi2;
280 bool has_wdrbt;
281 bool has_dma_support;
282 };
283
284 /*
285 * The core SPI transfer engine just talks to a register bank to set up
286 * DMA transfers; transfer queue progress is driven by IRQs. The clock
287 * framework provides the base clock, subdivided for each spi_device.
288 */
289 struct atmel_spi {
290 spinlock_t lock;
291 unsigned long flags;
292
293 phys_addr_t phybase;
294 void __iomem *regs;
295 int irq;
296 struct clk *clk;
297 struct platform_device *pdev;
298
299 struct spi_transfer *current_transfer;
300 int current_remaining_bytes;
301 int done_status;
302
303 struct completion xfer_completion;
304
305 /* scratch buffer */
306 void *buffer;
307 dma_addr_t buffer_dma;
308
309 struct atmel_spi_caps caps;
310
311 bool use_dma;
312 bool use_pdc;
313 bool use_cs_gpios;
314 /* dmaengine data */
315 struct atmel_spi_dma dma;
316
317 bool keep_cs;
318 bool cs_active;
319
320 u32 fifo_size;
321 };
322
323 /* Controller-specific per-slave state */
324 struct atmel_spi_device {
325 unsigned int npcs_pin;
326 u32 csr;
327 };
328
329 #define BUFFER_SIZE PAGE_SIZE
330 #define INVALID_DMA_ADDRESS 0xffffffff
331
332 /*
333 * Version 2 of the SPI controller has
334 * - CR.LASTXFER
335 * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero)
336 * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
337 * - SPI_CSRx.CSAAT
338 * - SPI_CSRx.SBCR allows faster clocking
339 */
340 static bool atmel_spi_is_v2(struct atmel_spi *as)
341 {
342 return as->caps.is_spi2;
343 }
344
345 /*
346 * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby
347 * they assume that spi slave device state will not change on deselect, so
348 * that automagic deselection is OK. ("NPCSx rises if no data is to be
349 * transmitted") Not so! Workaround uses nCSx pins as GPIOs; or newer
350 * controllers have CSAAT and friends.
351 *
352 * Since the CSAAT functionality is a bit weird on newer controllers as
353 * well, we use GPIO to control nCSx pins on all controllers, updating
354 * MR.PCS to avoid confusing the controller. Using GPIOs also lets us
355 * support active-high chipselects despite the controller's belief that
356 * only active-low devices/systems exists.
357 *
358 * However, at91rm9200 has a second erratum whereby nCS0 doesn't work
359 * right when driven with GPIO. ("Mode Fault does not allow more than one
360 * Master on Chip Select 0.") No workaround exists for that ... so for
361 * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH,
362 * and (c) will trigger that first erratum in some cases.
363 */
364
365 static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
366 {
367 struct atmel_spi_device *asd = spi->controller_state;
368 unsigned active = spi->mode & SPI_CS_HIGH;
369 u32 mr;
370
371 if (atmel_spi_is_v2(as)) {
372 spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr);
373 /* For the low SPI version, there is a issue that PDC transfer
374 * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS
375 */
376 spi_writel(as, CSR0, asd->csr);
377 if (as->caps.has_wdrbt) {
378 spi_writel(as, MR,
379 SPI_BF(PCS, ~(0x01 << spi->chip_select))
380 | SPI_BIT(WDRBT)
381 | SPI_BIT(MODFDIS)
382 | SPI_BIT(MSTR));
383 } else {
384 spi_writel(as, MR,
385 SPI_BF(PCS, ~(0x01 << spi->chip_select))
386 | SPI_BIT(MODFDIS)
387 | SPI_BIT(MSTR));
388 }
389
390 mr = spi_readl(as, MR);
391 if (as->use_cs_gpios)
392 gpio_set_value(asd->npcs_pin, active);
393 } else {
394 u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
395 int i;
396 u32 csr;
397
398 /* Make sure clock polarity is correct */
399 for (i = 0; i < spi->master->num_chipselect; i++) {
400 csr = spi_readl(as, CSR0 + 4 * i);
401 if ((csr ^ cpol) & SPI_BIT(CPOL))
402 spi_writel(as, CSR0 + 4 * i,
403 csr ^ SPI_BIT(CPOL));
404 }
405
406 mr = spi_readl(as, MR);
407 mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
408 if (as->use_cs_gpios && spi->chip_select != 0)
409 gpio_set_value(asd->npcs_pin, active);
410 spi_writel(as, MR, mr);
411 }
412
413 dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
414 asd->npcs_pin, active ? " (high)" : "",
415 mr);
416 }
417
418 static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
419 {
420 struct atmel_spi_device *asd = spi->controller_state;
421 unsigned active = spi->mode & SPI_CS_HIGH;
422 u32 mr;
423
424 /* only deactivate *this* device; sometimes transfers to
425 * another device may be active when this routine is called.
426 */
427 mr = spi_readl(as, MR);
428 if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
429 mr = SPI_BFINS(PCS, 0xf, mr);
430 spi_writel(as, MR, mr);
431 }
432
433 dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
434 asd->npcs_pin, active ? " (low)" : "",
435 mr);
436
437 if (!as->use_cs_gpios)
438 spi_writel(as, CR, SPI_BIT(LASTXFER));
439 else if (atmel_spi_is_v2(as) || spi->chip_select != 0)
440 gpio_set_value(asd->npcs_pin, !active);
441 }
442
443 static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock)
444 {
445 spin_lock_irqsave(&as->lock, as->flags);
446 }
447
448 static void atmel_spi_unlock(struct atmel_spi *as) __releases(&as->lock)
449 {
450 spin_unlock_irqrestore(&as->lock, as->flags);
451 }
452
453 static inline bool atmel_spi_use_dma(struct atmel_spi *as,
454 struct spi_transfer *xfer)
455 {
456 return as->use_dma && xfer->len >= DMA_MIN_BYTES;
457 }
458
459 static int atmel_spi_dma_slave_config(struct atmel_spi *as,
460 struct dma_slave_config *slave_config,
461 u8 bits_per_word)
462 {
463 int err = 0;
464
465 if (bits_per_word > 8) {
466 slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
467 slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
468 } else {
469 slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
470 slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
471 }
472
473 slave_config->dst_addr = (dma_addr_t)as->phybase + SPI_TDR;
474 slave_config->src_addr = (dma_addr_t)as->phybase + SPI_RDR;
475 slave_config->src_maxburst = 1;
476 slave_config->dst_maxburst = 1;
477 slave_config->device_fc = false;
478
479 /*
480 * This driver uses fixed peripheral select mode (PS bit set to '0' in
481 * the Mode Register).
482 * So according to the datasheet, when FIFOs are available (and
483 * enabled), the Transmit FIFO operates in Multiple Data Mode.
484 * In this mode, up to 2 data, not 4, can be written into the Transmit
485 * Data Register in a single access.
486 * However, the first data has to be written into the lowest 16 bits and
487 * the second data into the highest 16 bits of the Transmit
488 * Data Register. For 8bit data (the most frequent case), it would
489 * require to rework tx_buf so each data would actualy fit 16 bits.
490 * So we'd rather write only one data at the time. Hence the transmit
491 * path works the same whether FIFOs are available (and enabled) or not.
492 */
493 slave_config->direction = DMA_MEM_TO_DEV;
494 if (dmaengine_slave_config(as->dma.chan_tx, slave_config)) {
495 dev_err(&as->pdev->dev,
496 "failed to configure tx dma channel\n");
497 err = -EINVAL;
498 }
499
500 /*
501 * This driver configures the spi controller for master mode (MSTR bit
502 * set to '1' in the Mode Register).
503 * So according to the datasheet, when FIFOs are available (and
504 * enabled), the Receive FIFO operates in Single Data Mode.
505 * So the receive path works the same whether FIFOs are available (and
506 * enabled) or not.
507 */
508 slave_config->direction = DMA_DEV_TO_MEM;
509 if (dmaengine_slave_config(as->dma.chan_rx, slave_config)) {
510 dev_err(&as->pdev->dev,
511 "failed to configure rx dma channel\n");
512 err = -EINVAL;
513 }
514
515 return err;
516 }
517
518 static int atmel_spi_configure_dma(struct atmel_spi *as)
519 {
520 struct dma_slave_config slave_config;
521 struct device *dev = &as->pdev->dev;
522 int err;
523
524 dma_cap_mask_t mask;
525 dma_cap_zero(mask);
526 dma_cap_set(DMA_SLAVE, mask);
527
528 as->dma.chan_tx = dma_request_slave_channel_reason(dev, "tx");
529 if (IS_ERR(as->dma.chan_tx)) {
530 err = PTR_ERR(as->dma.chan_tx);
531 if (err == -EPROBE_DEFER) {
532 dev_warn(dev, "no DMA channel available at the moment\n");
533 return err;
534 }
535 dev_err(dev,
536 "DMA TX channel not available, SPI unable to use DMA\n");
537 err = -EBUSY;
538 goto error;
539 }
540
541 /*
542 * No reason to check EPROBE_DEFER here since we have already requested
543 * tx channel. If it fails here, it's for another reason.
544 */
545 as->dma.chan_rx = dma_request_slave_channel(dev, "rx");
546
547 if (!as->dma.chan_rx) {
548 dev_err(dev,
549 "DMA RX channel not available, SPI unable to use DMA\n");
550 err = -EBUSY;
551 goto error;
552 }
553
554 err = atmel_spi_dma_slave_config(as, &slave_config, 8);
555 if (err)
556 goto error;
557
558 dev_info(&as->pdev->dev,
559 "Using %s (tx) and %s (rx) for DMA transfers\n",
560 dma_chan_name(as->dma.chan_tx),
561 dma_chan_name(as->dma.chan_rx));
562 return 0;
563 error:
564 if (as->dma.chan_rx)
565 dma_release_channel(as->dma.chan_rx);
566 if (!IS_ERR(as->dma.chan_tx))
567 dma_release_channel(as->dma.chan_tx);
568 return err;
569 }
570
571 static void atmel_spi_stop_dma(struct atmel_spi *as)
572 {
573 if (as->dma.chan_rx)
574 dmaengine_terminate_all(as->dma.chan_rx);
575 if (as->dma.chan_tx)
576 dmaengine_terminate_all(as->dma.chan_tx);
577 }
578
579 static void atmel_spi_release_dma(struct atmel_spi *as)
580 {
581 if (as->dma.chan_rx)
582 dma_release_channel(as->dma.chan_rx);
583 if (as->dma.chan_tx)
584 dma_release_channel(as->dma.chan_tx);
585 }
586
587 /* This function is called by the DMA driver from tasklet context */
588 static void dma_callback(void *data)
589 {
590 struct spi_master *master = data;
591 struct atmel_spi *as = spi_master_get_devdata(master);
592
593 complete(&as->xfer_completion);
594 }
595
596 /*
597 * Next transfer using PIO without FIFO.
598 */
599 static void atmel_spi_next_xfer_single(struct spi_master *master,
600 struct spi_transfer *xfer)
601 {
602 struct atmel_spi *as = spi_master_get_devdata(master);
603 unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;
604
605 dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_pio\n");
606
607 /* Make sure data is not remaining in RDR */
608 spi_readl(as, RDR);
609 while (spi_readl(as, SR) & SPI_BIT(RDRF)) {
610 spi_readl(as, RDR);
611 cpu_relax();
612 }
613
614 if (xfer->tx_buf) {
615 if (xfer->bits_per_word > 8)
616 spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos));
617 else
618 spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos));
619 } else {
620 spi_writel(as, TDR, 0);
621 }
622
623 dev_dbg(master->dev.parent,
624 " start pio xfer %p: len %u tx %p rx %p bitpw %d\n",
625 xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
626 xfer->bits_per_word);
627
628 /* Enable relevant interrupts */
629 spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES));
630 }
631
632 /*
633 * Next transfer using PIO with FIFO.
634 */
635 static void atmel_spi_next_xfer_fifo(struct spi_master *master,
636 struct spi_transfer *xfer)
637 {
638 struct atmel_spi *as = spi_master_get_devdata(master);
639 u32 current_remaining_data, num_data;
640 u32 offset = xfer->len - as->current_remaining_bytes;
641 const u16 *words = (const u16 *)((u8 *)xfer->tx_buf + offset);
642 const u8 *bytes = (const u8 *)((u8 *)xfer->tx_buf + offset);
643 u16 td0, td1;
644 u32 fifomr;
645
646 dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_fifo\n");
647
648 /* Compute the number of data to transfer in the current iteration */
649 current_remaining_data = ((xfer->bits_per_word > 8) ?
650 ((u32)as->current_remaining_bytes >> 1) :
651 (u32)as->current_remaining_bytes);
652 num_data = min(current_remaining_data, as->fifo_size);
653
654 /* Flush RX and TX FIFOs */
655 spi_writel(as, CR, SPI_BIT(RXFCLR) | SPI_BIT(TXFCLR));
656 while (spi_readl(as, FLR))
657 cpu_relax();
658
659 /* Set RX FIFO Threshold to the number of data to transfer */
660 fifomr = spi_readl(as, FMR);
661 spi_writel(as, FMR, SPI_BFINS(RXFTHRES, num_data, fifomr));
662
663 /* Clear FIFO flags in the Status Register, especially RXFTHF */
664 (void)spi_readl(as, SR);
665
666 /* Fill TX FIFO */
667 while (num_data >= 2) {
668 if (xfer->tx_buf) {
669 if (xfer->bits_per_word > 8) {
670 td0 = *words++;
671 td1 = *words++;
672 } else {
673 td0 = *bytes++;
674 td1 = *bytes++;
675 }
676 } else {
677 td0 = 0;
678 td1 = 0;
679 }
680
681 spi_writel(as, TDR, (td1 << 16) | td0);
682 num_data -= 2;
683 }
684
685 if (num_data) {
686 if (xfer->tx_buf) {
687 if (xfer->bits_per_word > 8)
688 td0 = *words++;
689 else
690 td0 = *bytes++;
691 } else {
692 td0 = 0;
693 }
694
695 spi_writew(as, TDR, td0);
696 num_data--;
697 }
698
699 dev_dbg(master->dev.parent,
700 " start fifo xfer %p: len %u tx %p rx %p bitpw %d\n",
701 xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
702 xfer->bits_per_word);
703
704 /*
705 * Enable RX FIFO Threshold Flag interrupt to be notified about
706 * transfer completion.
707 */
708 spi_writel(as, IER, SPI_BIT(RXFTHF) | SPI_BIT(OVRES));
709 }
710
711 /*
712 * Next transfer using PIO.
713 */
714 static void atmel_spi_next_xfer_pio(struct spi_master *master,
715 struct spi_transfer *xfer)
716 {
717 struct atmel_spi *as = spi_master_get_devdata(master);
718
719 if (as->fifo_size)
720 atmel_spi_next_xfer_fifo(master, xfer);
721 else
722 atmel_spi_next_xfer_single(master, xfer);
723 }
724
725 /*
726 * Submit next transfer for DMA.
727 */
728 static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
729 struct spi_transfer *xfer,
730 u32 *plen)
731 {
732 struct atmel_spi *as = spi_master_get_devdata(master);
733 struct dma_chan *rxchan = as->dma.chan_rx;
734 struct dma_chan *txchan = as->dma.chan_tx;
735 struct dma_async_tx_descriptor *rxdesc;
736 struct dma_async_tx_descriptor *txdesc;
737 struct dma_slave_config slave_config;
738 dma_cookie_t cookie;
739 u32 len = *plen;
740
741 dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma_submit\n");
742
743 /* Check that the channels are available */
744 if (!rxchan || !txchan)
745 return -ENODEV;
746
747 /* release lock for DMA operations */
748 atmel_spi_unlock(as);
749
750 /* prepare the RX dma transfer */
751 sg_init_table(&as->dma.sgrx, 1);
752 if (xfer->rx_buf) {
753 as->dma.sgrx.dma_address = xfer->rx_dma + xfer->len - *plen;
754 } else {
755 as->dma.sgrx.dma_address = as->buffer_dma;
756 if (len > BUFFER_SIZE)
757 len = BUFFER_SIZE;
758 }
759
760 /* prepare the TX dma transfer */
761 sg_init_table(&as->dma.sgtx, 1);
762 if (xfer->tx_buf) {
763 as->dma.sgtx.dma_address = xfer->tx_dma + xfer->len - *plen;
764 } else {
765 as->dma.sgtx.dma_address = as->buffer_dma;
766 if (len > BUFFER_SIZE)
767 len = BUFFER_SIZE;
768 memset(as->buffer, 0, len);
769 }
770
771 sg_dma_len(&as->dma.sgtx) = len;
772 sg_dma_len(&as->dma.sgrx) = len;
773
774 *plen = len;
775
776 if (atmel_spi_dma_slave_config(as, &slave_config,
777 xfer->bits_per_word))
778 goto err_exit;
779
780 /* Send both scatterlists */
781 rxdesc = dmaengine_prep_slave_sg(rxchan, &as->dma.sgrx, 1,
782 DMA_FROM_DEVICE,
783 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
784 if (!rxdesc)
785 goto err_dma;
786
787 txdesc = dmaengine_prep_slave_sg(txchan, &as->dma.sgtx, 1,
788 DMA_TO_DEVICE,
789 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
790 if (!txdesc)
791 goto err_dma;
792
793 dev_dbg(master->dev.parent,
794 " start dma xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
795 xfer, xfer->len, xfer->tx_buf, (unsigned long long)xfer->tx_dma,
796 xfer->rx_buf, (unsigned long long)xfer->rx_dma);
797
798 /* Enable relevant interrupts */
799 spi_writel(as, IER, SPI_BIT(OVRES));
800
801 /* Put the callback on the RX transfer only, that should finish last */
802 rxdesc->callback = dma_callback;
803 rxdesc->callback_param = master;
804
805 /* Submit and fire RX and TX with TX last so we're ready to read! */
806 cookie = rxdesc->tx_submit(rxdesc);
807 if (dma_submit_error(cookie))
808 goto err_dma;
809 cookie = txdesc->tx_submit(txdesc);
810 if (dma_submit_error(cookie))
811 goto err_dma;
812 rxchan->device->device_issue_pending(rxchan);
813 txchan->device->device_issue_pending(txchan);
814
815 /* take back lock */
816 atmel_spi_lock(as);
817 return 0;
818
819 err_dma:
820 spi_writel(as, IDR, SPI_BIT(OVRES));
821 atmel_spi_stop_dma(as);
822 err_exit:
823 atmel_spi_lock(as);
824 return -ENOMEM;
825 }
826
827 static void atmel_spi_next_xfer_data(struct spi_master *master,
828 struct spi_transfer *xfer,
829 dma_addr_t *tx_dma,
830 dma_addr_t *rx_dma,
831 u32 *plen)
832 {
833 struct atmel_spi *as = spi_master_get_devdata(master);
834 u32 len = *plen;
835
836 /* use scratch buffer only when rx or tx data is unspecified */
837 if (xfer->rx_buf)
838 *rx_dma = xfer->rx_dma + xfer->len - *plen;
839 else {
840 *rx_dma = as->buffer_dma;
841 if (len > BUFFER_SIZE)
842 len = BUFFER_SIZE;
843 }
844
845 if (xfer->tx_buf)
846 *tx_dma = xfer->tx_dma + xfer->len - *plen;
847 else {
848 *tx_dma = as->buffer_dma;
849 if (len > BUFFER_SIZE)
850 len = BUFFER_SIZE;
851 memset(as->buffer, 0, len);
852 dma_sync_single_for_device(&as->pdev->dev,
853 as->buffer_dma, len, DMA_TO_DEVICE);
854 }
855
856 *plen = len;
857 }
858
859 static int atmel_spi_set_xfer_speed(struct atmel_spi *as,
860 struct spi_device *spi,
861 struct spi_transfer *xfer)
862 {
863 u32 scbr, csr;
864 unsigned long bus_hz;
865
866 /* v1 chips start out at half the peripheral bus speed. */
867 bus_hz = clk_get_rate(as->clk);
868 if (!atmel_spi_is_v2(as))
869 bus_hz /= 2;
870
871 /*
872 * Calculate the lowest divider that satisfies the
873 * constraint, assuming div32/fdiv/mbz == 0.
874 */
875 scbr = DIV_ROUND_UP(bus_hz, xfer->speed_hz);
876
877 /*
878 * If the resulting divider doesn't fit into the
879 * register bitfield, we can't satisfy the constraint.
880 */
881 if (scbr >= (1 << SPI_SCBR_SIZE)) {
882 dev_err(&spi->dev,
883 "setup: %d Hz too slow, scbr %u; min %ld Hz\n",
884 xfer->speed_hz, scbr, bus_hz/255);
885 return -EINVAL;
886 }
887 if (scbr == 0) {
888 dev_err(&spi->dev,
889 "setup: %d Hz too high, scbr %u; max %ld Hz\n",
890 xfer->speed_hz, scbr, bus_hz);
891 return -EINVAL;
892 }
893 csr = spi_readl(as, CSR0 + 4 * spi->chip_select);
894 csr = SPI_BFINS(SCBR, scbr, csr);
895 spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
896
897 return 0;
898 }
899
900 /*
901 * Submit next transfer for PDC.
902 * lock is held, spi irq is blocked
903 */
904 static void atmel_spi_pdc_next_xfer(struct spi_master *master,
905 struct spi_message *msg,
906 struct spi_transfer *xfer)
907 {
908 struct atmel_spi *as = spi_master_get_devdata(master);
909 u32 len;
910 dma_addr_t tx_dma, rx_dma;
911
912 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
913
914 len = as->current_remaining_bytes;
915 atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
916 as->current_remaining_bytes -= len;
917
918 spi_writel(as, RPR, rx_dma);
919 spi_writel(as, TPR, tx_dma);
920
921 if (msg->spi->bits_per_word > 8)
922 len >>= 1;
923 spi_writel(as, RCR, len);
924 spi_writel(as, TCR, len);
925
926 dev_dbg(&msg->spi->dev,
927 " start xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
928 xfer, xfer->len, xfer->tx_buf,
929 (unsigned long long)xfer->tx_dma, xfer->rx_buf,
930 (unsigned long long)xfer->rx_dma);
931
932 if (as->current_remaining_bytes) {
933 len = as->current_remaining_bytes;
934 atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
935 as->current_remaining_bytes -= len;
936
937 spi_writel(as, RNPR, rx_dma);
938 spi_writel(as, TNPR, tx_dma);
939
940 if (msg->spi->bits_per_word > 8)
941 len >>= 1;
942 spi_writel(as, RNCR, len);
943 spi_writel(as, TNCR, len);
944
945 dev_dbg(&msg->spi->dev,
946 " next xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
947 xfer, xfer->len, xfer->tx_buf,
948 (unsigned long long)xfer->tx_dma, xfer->rx_buf,
949 (unsigned long long)xfer->rx_dma);
950 }
951
952 /* REVISIT: We're waiting for RXBUFF before we start the next
953 * transfer because we need to handle some difficult timing
954 * issues otherwise. If we wait for TXBUFE in one transfer and
955 * then starts waiting for RXBUFF in the next, it's difficult
956 * to tell the difference between the RXBUFF interrupt we're
957 * actually waiting for and the RXBUFF interrupt of the
958 * previous transfer.
959 *
960 * It should be doable, though. Just not now...
961 */
962 spi_writel(as, IER, SPI_BIT(RXBUFF) | SPI_BIT(OVRES));
963 spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN));
964 }
965
966 /*
967 * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma:
968 * - The buffer is either valid for CPU access, else NULL
969 * - If the buffer is valid, so is its DMA address
970 *
971 * This driver manages the dma address unless message->is_dma_mapped.
972 */
973 static int
974 atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer)
975 {
976 struct device *dev = &as->pdev->dev;
977
978 xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS;
979 if (xfer->tx_buf) {
980 /* tx_buf is a const void* where we need a void * for the dma
981 * mapping */
982 void *nonconst_tx = (void *)xfer->tx_buf;
983
984 xfer->tx_dma = dma_map_single(dev,
985 nonconst_tx, xfer->len,
986 DMA_TO_DEVICE);
987 if (dma_mapping_error(dev, xfer->tx_dma))
988 return -ENOMEM;
989 }
990 if (xfer->rx_buf) {
991 xfer->rx_dma = dma_map_single(dev,
992 xfer->rx_buf, xfer->len,
993 DMA_FROM_DEVICE);
994 if (dma_mapping_error(dev, xfer->rx_dma)) {
995 if (xfer->tx_buf)
996 dma_unmap_single(dev,
997 xfer->tx_dma, xfer->len,
998 DMA_TO_DEVICE);
999 return -ENOMEM;
1000 }
1001 }
1002 return 0;
1003 }
1004
1005 static void atmel_spi_dma_unmap_xfer(struct spi_master *master,
1006 struct spi_transfer *xfer)
1007 {
1008 if (xfer->tx_dma != INVALID_DMA_ADDRESS)
1009 dma_unmap_single(master->dev.parent, xfer->tx_dma,
1010 xfer->len, DMA_TO_DEVICE);
1011 if (xfer->rx_dma != INVALID_DMA_ADDRESS)
1012 dma_unmap_single(master->dev.parent, xfer->rx_dma,
1013 xfer->len, DMA_FROM_DEVICE);
1014 }
1015
1016 static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as)
1017 {
1018 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
1019 }
1020
1021 static void
1022 atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer)
1023 {
1024 u8 *rxp;
1025 u16 *rxp16;
1026 unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;
1027
1028 if (xfer->rx_buf) {
1029 if (xfer->bits_per_word > 8) {
1030 rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos);
1031 *rxp16 = spi_readl(as, RDR);
1032 } else {
1033 rxp = ((u8 *)xfer->rx_buf) + xfer_pos;
1034 *rxp = spi_readl(as, RDR);
1035 }
1036 } else {
1037 spi_readl(as, RDR);
1038 }
1039 if (xfer->bits_per_word > 8) {
1040 if (as->current_remaining_bytes > 2)
1041 as->current_remaining_bytes -= 2;
1042 else
1043 as->current_remaining_bytes = 0;
1044 } else {
1045 as->current_remaining_bytes--;
1046 }
1047 }
1048
1049 static void
1050 atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer)
1051 {
1052 u32 fifolr = spi_readl(as, FLR);
1053 u32 num_bytes, num_data = SPI_BFEXT(RXFL, fifolr);
1054 u32 offset = xfer->len - as->current_remaining_bytes;
1055 u16 *words = (u16 *)((u8 *)xfer->rx_buf + offset);
1056 u8 *bytes = (u8 *)((u8 *)xfer->rx_buf + offset);
1057 u16 rd; /* RD field is the lowest 16 bits of RDR */
1058
1059 /* Update the number of remaining bytes to transfer */
1060 num_bytes = ((xfer->bits_per_word > 8) ?
1061 (num_data << 1) :
1062 num_data);
1063
1064 if (as->current_remaining_bytes > num_bytes)
1065 as->current_remaining_bytes -= num_bytes;
1066 else
1067 as->current_remaining_bytes = 0;
1068
1069 /* Handle odd number of bytes when data are more than 8bit width */
1070 if (xfer->bits_per_word > 8)
1071 as->current_remaining_bytes &= ~0x1;
1072
1073 /* Read data */
1074 while (num_data) {
1075 rd = spi_readl(as, RDR);
1076 if (xfer->rx_buf) {
1077 if (xfer->bits_per_word > 8)
1078 *words++ = rd;
1079 else
1080 *bytes++ = rd;
1081 }
1082 num_data--;
1083 }
1084 }
1085
1086 /* Called from IRQ
1087 *
1088 * Must update "current_remaining_bytes" to keep track of data
1089 * to transfer.
1090 */
1091 static void
1092 atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
1093 {
1094 if (as->fifo_size)
1095 atmel_spi_pump_fifo_data(as, xfer);
1096 else
1097 atmel_spi_pump_single_data(as, xfer);
1098 }
1099
1100 /* Interrupt
1101 *
1102 * No need for locking in this Interrupt handler: done_status is the
1103 * only information modified.
1104 */
1105 static irqreturn_t
1106 atmel_spi_pio_interrupt(int irq, void *dev_id)
1107 {
1108 struct spi_master *master = dev_id;
1109 struct atmel_spi *as = spi_master_get_devdata(master);
1110 u32 status, pending, imr;
1111 struct spi_transfer *xfer;
1112 int ret = IRQ_NONE;
1113
1114 imr = spi_readl(as, IMR);
1115 status = spi_readl(as, SR);
1116 pending = status & imr;
1117
1118 if (pending & SPI_BIT(OVRES)) {
1119 ret = IRQ_HANDLED;
1120 spi_writel(as, IDR, SPI_BIT(OVRES));
1121 dev_warn(master->dev.parent, "overrun\n");
1122
1123 /*
1124 * When we get an overrun, we disregard the current
1125 * transfer. Data will not be copied back from any
1126 * bounce buffer and msg->actual_len will not be
1127 * updated with the last xfer.
1128 *
1129 * We will also not process any remaning transfers in
1130 * the message.
1131 */
1132 as->done_status = -EIO;
1133 smp_wmb();
1134
1135 /* Clear any overrun happening while cleaning up */
1136 spi_readl(as, SR);
1137
1138 complete(&as->xfer_completion);
1139
1140 } else if (pending & (SPI_BIT(RDRF) | SPI_BIT(RXFTHF))) {
1141 atmel_spi_lock(as);
1142
1143 if (as->current_remaining_bytes) {
1144 ret = IRQ_HANDLED;
1145 xfer = as->current_transfer;
1146 atmel_spi_pump_pio_data(as, xfer);
1147 if (!as->current_remaining_bytes)
1148 spi_writel(as, IDR, pending);
1149
1150 complete(&as->xfer_completion);
1151 }
1152
1153 atmel_spi_unlock(as);
1154 } else {
1155 WARN_ONCE(pending, "IRQ not handled, pending = %x\n", pending);
1156 ret = IRQ_HANDLED;
1157 spi_writel(as, IDR, pending);
1158 }
1159
1160 return ret;
1161 }
1162
1163 static irqreturn_t
1164 atmel_spi_pdc_interrupt(int irq, void *dev_id)
1165 {
1166 struct spi_master *master = dev_id;
1167 struct atmel_spi *as = spi_master_get_devdata(master);
1168 u32 status, pending, imr;
1169 int ret = IRQ_NONE;
1170
1171 imr = spi_readl(as, IMR);
1172 status = spi_readl(as, SR);
1173 pending = status & imr;
1174
1175 if (pending & SPI_BIT(OVRES)) {
1176
1177 ret = IRQ_HANDLED;
1178
1179 spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX)
1180 | SPI_BIT(OVRES)));
1181
1182 /* Clear any overrun happening while cleaning up */
1183 spi_readl(as, SR);
1184
1185 as->done_status = -EIO;
1186
1187 complete(&as->xfer_completion);
1188
1189 } else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) {
1190 ret = IRQ_HANDLED;
1191
1192 spi_writel(as, IDR, pending);
1193
1194 complete(&as->xfer_completion);
1195 }
1196
1197 return ret;
1198 }
1199
1200 static int atmel_spi_setup(struct spi_device *spi)
1201 {
1202 struct atmel_spi *as;
1203 struct atmel_spi_device *asd;
1204 u32 csr;
1205 unsigned int bits = spi->bits_per_word;
1206 unsigned int npcs_pin;
1207 int ret;
1208
1209 as = spi_master_get_devdata(spi->master);
1210
1211 /* see notes above re chipselect */
1212 if (!atmel_spi_is_v2(as)
1213 && spi->chip_select == 0
1214 && (spi->mode & SPI_CS_HIGH)) {
1215 dev_dbg(&spi->dev, "setup: can't be active-high\n");
1216 return -EINVAL;
1217 }
1218
1219 csr = SPI_BF(BITS, bits - 8);
1220 if (spi->mode & SPI_CPOL)
1221 csr |= SPI_BIT(CPOL);
1222 if (!(spi->mode & SPI_CPHA))
1223 csr |= SPI_BIT(NCPHA);
1224 if (!as->use_cs_gpios)
1225 csr |= SPI_BIT(CSAAT);
1226
1227 /* DLYBS is mostly irrelevant since we manage chipselect using GPIOs.
1228 *
1229 * DLYBCT would add delays between words, slowing down transfers.
1230 * It could potentially be useful to cope with DMA bottlenecks, but
1231 * in those cases it's probably best to just use a lower bitrate.
1232 */
1233 csr |= SPI_BF(DLYBS, 0);
1234 csr |= SPI_BF(DLYBCT, 0);
1235
1236 /* chipselect must have been muxed as GPIO (e.g. in board setup) */
1237 npcs_pin = (unsigned long)spi->controller_data;
1238
1239 if (!as->use_cs_gpios)
1240 npcs_pin = spi->chip_select;
1241 else if (gpio_is_valid(spi->cs_gpio))
1242 npcs_pin = spi->cs_gpio;
1243
1244 asd = spi->controller_state;
1245 if (!asd) {
1246 asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL);
1247 if (!asd)
1248 return -ENOMEM;
1249
1250 if (as->use_cs_gpios) {
1251 ret = gpio_request(npcs_pin, dev_name(&spi->dev));
1252 if (ret) {
1253 kfree(asd);
1254 return ret;
1255 }
1256
1257 gpio_direction_output(npcs_pin,
1258 !(spi->mode & SPI_CS_HIGH));
1259 }
1260
1261 asd->npcs_pin = npcs_pin;
1262 spi->controller_state = asd;
1263 }
1264
1265 asd->csr = csr;
1266
1267 dev_dbg(&spi->dev,
1268 "setup: bpw %u mode 0x%x -> csr%d %08x\n",
1269 bits, spi->mode, spi->chip_select, csr);
1270
1271 if (!atmel_spi_is_v2(as))
1272 spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
1273
1274 return 0;
1275 }
1276
1277 static int atmel_spi_one_transfer(struct spi_master *master,
1278 struct spi_message *msg,
1279 struct spi_transfer *xfer)
1280 {
1281 struct atmel_spi *as;
1282 struct spi_device *spi = msg->spi;
1283 u8 bits;
1284 u32 len;
1285 struct atmel_spi_device *asd;
1286 int timeout;
1287 int ret;
1288 unsigned long dma_timeout;
1289
1290 as = spi_master_get_devdata(master);
1291
1292 if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1293 dev_dbg(&spi->dev, "missing rx or tx buf\n");
1294 return -EINVAL;
1295 }
1296
1297 asd = spi->controller_state;
1298 bits = (asd->csr >> 4) & 0xf;
1299 if (bits != xfer->bits_per_word - 8) {
1300 dev_dbg(&spi->dev,
1301 "you can't yet change bits_per_word in transfers\n");
1302 return -ENOPROTOOPT;
1303 }
1304
1305 /*
1306 * DMA map early, for performance (empties dcache ASAP) and
1307 * better fault reporting.
1308 */
1309 if ((!msg->is_dma_mapped)
1310 && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) {
1311 if (atmel_spi_dma_map_xfer(as, xfer) < 0)
1312 return -ENOMEM;
1313 }
1314
1315 atmel_spi_set_xfer_speed(as, msg->spi, xfer);
1316
1317 as->done_status = 0;
1318 as->current_transfer = xfer;
1319 as->current_remaining_bytes = xfer->len;
1320 while (as->current_remaining_bytes) {
1321 reinit_completion(&as->xfer_completion);
1322
1323 if (as->use_pdc) {
1324 atmel_spi_pdc_next_xfer(master, msg, xfer);
1325 } else if (atmel_spi_use_dma(as, xfer)) {
1326 len = as->current_remaining_bytes;
1327 ret = atmel_spi_next_xfer_dma_submit(master,
1328 xfer, &len);
1329 if (ret) {
1330 dev_err(&spi->dev,
1331 "unable to use DMA, fallback to PIO\n");
1332 atmel_spi_next_xfer_pio(master, xfer);
1333 } else {
1334 as->current_remaining_bytes -= len;
1335 if (as->current_remaining_bytes < 0)
1336 as->current_remaining_bytes = 0;
1337 }
1338 } else {
1339 atmel_spi_next_xfer_pio(master, xfer);
1340 }
1341
1342 /* interrupts are disabled, so free the lock for schedule */
1343 atmel_spi_unlock(as);
1344 dma_timeout = wait_for_completion_timeout(&as->xfer_completion,
1345 SPI_DMA_TIMEOUT);
1346 atmel_spi_lock(as);
1347 if (WARN_ON(dma_timeout == 0)) {
1348 dev_err(&spi->dev, "spi transfer timeout\n");
1349 as->done_status = -EIO;
1350 }
1351
1352 if (as->done_status)
1353 break;
1354 }
1355
1356 if (as->done_status) {
1357 if (as->use_pdc) {
1358 dev_warn(master->dev.parent,
1359 "overrun (%u/%u remaining)\n",
1360 spi_readl(as, TCR), spi_readl(as, RCR));
1361
1362 /*
1363 * Clean up DMA registers and make sure the data
1364 * registers are empty.
1365 */
1366 spi_writel(as, RNCR, 0);
1367 spi_writel(as, TNCR, 0);
1368 spi_writel(as, RCR, 0);
1369 spi_writel(as, TCR, 0);
1370 for (timeout = 1000; timeout; timeout--)
1371 if (spi_readl(as, SR) & SPI_BIT(TXEMPTY))
1372 break;
1373 if (!timeout)
1374 dev_warn(master->dev.parent,
1375 "timeout waiting for TXEMPTY");
1376 while (spi_readl(as, SR) & SPI_BIT(RDRF))
1377 spi_readl(as, RDR);
1378
1379 /* Clear any overrun happening while cleaning up */
1380 spi_readl(as, SR);
1381
1382 } else if (atmel_spi_use_dma(as, xfer)) {
1383 atmel_spi_stop_dma(as);
1384 }
1385
1386 if (!msg->is_dma_mapped
1387 && (atmel_spi_use_dma(as, xfer) || as->use_pdc))
1388 atmel_spi_dma_unmap_xfer(master, xfer);
1389
1390 return 0;
1391
1392 } else {
1393 /* only update length if no error */
1394 msg->actual_length += xfer->len;
1395 }
1396
1397 if (!msg->is_dma_mapped
1398 && (atmel_spi_use_dma(as, xfer) || as->use_pdc))
1399 atmel_spi_dma_unmap_xfer(master, xfer);
1400
1401 if (xfer->delay_usecs)
1402 udelay(xfer->delay_usecs);
1403
1404 if (xfer->cs_change) {
1405 if (list_is_last(&xfer->transfer_list,
1406 &msg->transfers)) {
1407 as->keep_cs = true;
1408 } else {
1409 as->cs_active = !as->cs_active;
1410 if (as->cs_active)
1411 cs_activate(as, msg->spi);
1412 else
1413 cs_deactivate(as, msg->spi);
1414 }
1415 }
1416
1417 return 0;
1418 }
1419
1420 static int atmel_spi_transfer_one_message(struct spi_master *master,
1421 struct spi_message *msg)
1422 {
1423 struct atmel_spi *as;
1424 struct spi_transfer *xfer;
1425 struct spi_device *spi = msg->spi;
1426 int ret = 0;
1427
1428 as = spi_master_get_devdata(master);
1429
1430 dev_dbg(&spi->dev, "new message %p submitted for %s\n",
1431 msg, dev_name(&spi->dev));
1432
1433 atmel_spi_lock(as);
1434 cs_activate(as, spi);
1435
1436 as->cs_active = true;
1437 as->keep_cs = false;
1438
1439 msg->status = 0;
1440 msg->actual_length = 0;
1441
1442 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1443 ret = atmel_spi_one_transfer(master, msg, xfer);
1444 if (ret)
1445 goto msg_done;
1446 }
1447
1448 if (as->use_pdc)
1449 atmel_spi_disable_pdc_transfer(as);
1450
1451 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1452 dev_dbg(&spi->dev,
1453 " xfer %p: len %u tx %p/%pad rx %p/%pad\n",
1454 xfer, xfer->len,
1455 xfer->tx_buf, &xfer->tx_dma,
1456 xfer->rx_buf, &xfer->rx_dma);
1457 }
1458
1459 msg_done:
1460 if (!as->keep_cs)
1461 cs_deactivate(as, msg->spi);
1462
1463 atmel_spi_unlock(as);
1464
1465 msg->status = as->done_status;
1466 spi_finalize_current_message(spi->master);
1467
1468 return ret;
1469 }
1470
1471 static void atmel_spi_cleanup(struct spi_device *spi)
1472 {
1473 struct atmel_spi_device *asd = spi->controller_state;
1474 unsigned gpio = (unsigned long) spi->controller_data;
1475
1476 if (!asd)
1477 return;
1478
1479 spi->controller_state = NULL;
1480 gpio_free(gpio);
1481 kfree(asd);
1482 }
1483
1484 static inline unsigned int atmel_get_version(struct atmel_spi *as)
1485 {
1486 return spi_readl(as, VERSION) & 0x00000fff;
1487 }
1488
1489 static void atmel_get_caps(struct atmel_spi *as)
1490 {
1491 unsigned int version;
1492
1493 version = atmel_get_version(as);
1494 dev_info(&as->pdev->dev, "version: 0x%x\n", version);
1495
1496 as->caps.is_spi2 = version > 0x121;
1497 as->caps.has_wdrbt = version >= 0x210;
1498 as->caps.has_dma_support = version >= 0x212;
1499 }
1500
1501 /*-------------------------------------------------------------------------*/
1502
1503 static int atmel_spi_probe(struct platform_device *pdev)
1504 {
1505 struct resource *regs;
1506 int irq;
1507 struct clk *clk;
1508 int ret;
1509 struct spi_master *master;
1510 struct atmel_spi *as;
1511
1512 /* Select default pin state */
1513 pinctrl_pm_select_default_state(&pdev->dev);
1514
1515 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1516 if (!regs)
1517 return -ENXIO;
1518
1519 irq = platform_get_irq(pdev, 0);
1520 if (irq < 0)
1521 return irq;
1522
1523 clk = devm_clk_get(&pdev->dev, "spi_clk");
1524 if (IS_ERR(clk))
1525 return PTR_ERR(clk);
1526
1527 /* setup spi core then atmel-specific driver state */
1528 ret = -ENOMEM;
1529 master = spi_alloc_master(&pdev->dev, sizeof(*as));
1530 if (!master)
1531 goto out_free;
1532
1533 /* the spi->mode bits understood by this driver: */
1534 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1535 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
1536 master->dev.of_node = pdev->dev.of_node;
1537 master->bus_num = pdev->id;
1538 master->num_chipselect = master->dev.of_node ? 0 : 4;
1539 master->setup = atmel_spi_setup;
1540 master->transfer_one_message = atmel_spi_transfer_one_message;
1541 master->cleanup = atmel_spi_cleanup;
1542 master->auto_runtime_pm = true;
1543 platform_set_drvdata(pdev, master);
1544
1545 as = spi_master_get_devdata(master);
1546
1547 /*
1548 * Scratch buffer is used for throwaway rx and tx data.
1549 * It's coherent to minimize dcache pollution.
1550 */
1551 as->buffer = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE,
1552 &as->buffer_dma, GFP_KERNEL);
1553 if (!as->buffer)
1554 goto out_free;
1555
1556 spin_lock_init(&as->lock);
1557
1558 as->pdev = pdev;
1559 as->regs = devm_ioremap_resource(&pdev->dev, regs);
1560 if (IS_ERR(as->regs)) {
1561 ret = PTR_ERR(as->regs);
1562 goto out_free_buffer;
1563 }
1564 as->phybase = regs->start;
1565 as->irq = irq;
1566 as->clk = clk;
1567
1568 init_completion(&as->xfer_completion);
1569
1570 atmel_get_caps(as);
1571
1572 as->use_cs_gpios = true;
1573 if (atmel_spi_is_v2(as) &&
1574 pdev->dev.of_node &&
1575 !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) {
1576 as->use_cs_gpios = false;
1577 master->num_chipselect = 4;
1578 }
1579
1580 as->use_dma = false;
1581 as->use_pdc = false;
1582 if (as->caps.has_dma_support) {
1583 ret = atmel_spi_configure_dma(as);
1584 if (ret == 0)
1585 as->use_dma = true;
1586 else if (ret == -EPROBE_DEFER)
1587 return ret;
1588 } else {
1589 as->use_pdc = true;
1590 }
1591
1592 if (as->caps.has_dma_support && !as->use_dma)
1593 dev_info(&pdev->dev, "Atmel SPI Controller using PIO only\n");
1594
1595 if (as->use_pdc) {
1596 ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pdc_interrupt,
1597 0, dev_name(&pdev->dev), master);
1598 } else {
1599 ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pio_interrupt,
1600 0, dev_name(&pdev->dev), master);
1601 }
1602 if (ret)
1603 goto out_unmap_regs;
1604
1605 /* Initialize the hardware */
1606 ret = clk_prepare_enable(clk);
1607 if (ret)
1608 goto out_free_irq;
1609 spi_writel(as, CR, SPI_BIT(SWRST));
1610 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
1611 if (as->caps.has_wdrbt) {
1612 spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS)
1613 | SPI_BIT(MSTR));
1614 } else {
1615 spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
1616 }
1617
1618 if (as->use_pdc)
1619 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
1620 spi_writel(as, CR, SPI_BIT(SPIEN));
1621
1622 as->fifo_size = 0;
1623 if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size",
1624 &as->fifo_size)) {
1625 dev_info(&pdev->dev, "Using FIFO (%u data)\n", as->fifo_size);
1626 spi_writel(as, CR, SPI_BIT(FIFOEN));
1627 }
1628
1629 /* go! */
1630 dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n",
1631 (unsigned long)regs->start, irq);
1632
1633 pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1634 pm_runtime_use_autosuspend(&pdev->dev);
1635 pm_runtime_set_active(&pdev->dev);
1636 pm_runtime_enable(&pdev->dev);
1637
1638 ret = devm_spi_register_master(&pdev->dev, master);
1639 if (ret)
1640 goto out_free_dma;
1641
1642 return 0;
1643
1644 out_free_dma:
1645 pm_runtime_disable(&pdev->dev);
1646 pm_runtime_set_suspended(&pdev->dev);
1647
1648 if (as->use_dma)
1649 atmel_spi_release_dma(as);
1650
1651 spi_writel(as, CR, SPI_BIT(SWRST));
1652 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
1653 clk_disable_unprepare(clk);
1654 out_free_irq:
1655 out_unmap_regs:
1656 out_free_buffer:
1657 dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
1658 as->buffer_dma);
1659 out_free:
1660 spi_master_put(master);
1661 return ret;
1662 }
1663
1664 static int atmel_spi_remove(struct platform_device *pdev)
1665 {
1666 struct spi_master *master = platform_get_drvdata(pdev);
1667 struct atmel_spi *as = spi_master_get_devdata(master);
1668
1669 pm_runtime_get_sync(&pdev->dev);
1670
1671 /* reset the hardware and block queue progress */
1672 spin_lock_irq(&as->lock);
1673 if (as->use_dma) {
1674 atmel_spi_stop_dma(as);
1675 atmel_spi_release_dma(as);
1676 }
1677
1678 spi_writel(as, CR, SPI_BIT(SWRST));
1679 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
1680 spi_readl(as, SR);
1681 spin_unlock_irq(&as->lock);
1682
1683 dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer,
1684 as->buffer_dma);
1685
1686 clk_disable_unprepare(as->clk);
1687
1688 pm_runtime_put_noidle(&pdev->dev);
1689 pm_runtime_disable(&pdev->dev);
1690
1691 return 0;
1692 }
1693
1694 #ifdef CONFIG_PM
1695 static int atmel_spi_runtime_suspend(struct device *dev)
1696 {
1697 struct spi_master *master = dev_get_drvdata(dev);
1698 struct atmel_spi *as = spi_master_get_devdata(master);
1699
1700 clk_disable_unprepare(as->clk);
1701 pinctrl_pm_select_sleep_state(dev);
1702
1703 return 0;
1704 }
1705
1706 static int atmel_spi_runtime_resume(struct device *dev)
1707 {
1708 struct spi_master *master = dev_get_drvdata(dev);
1709 struct atmel_spi *as = spi_master_get_devdata(master);
1710
1711 pinctrl_pm_select_default_state(dev);
1712
1713 return clk_prepare_enable(as->clk);
1714 }
1715
1716 #ifdef CONFIG_PM_SLEEP
1717 static int atmel_spi_suspend(struct device *dev)
1718 {
1719 struct spi_master *master = dev_get_drvdata(dev);
1720 int ret;
1721
1722 /* Stop the queue running */
1723 ret = spi_master_suspend(master);
1724 if (ret) {
1725 dev_warn(dev, "cannot suspend master\n");
1726 return ret;
1727 }
1728
1729 if (!pm_runtime_suspended(dev))
1730 atmel_spi_runtime_suspend(dev);
1731
1732 return 0;
1733 }
1734
1735 static int atmel_spi_resume(struct device *dev)
1736 {
1737 struct spi_master *master = dev_get_drvdata(dev);
1738 int ret;
1739
1740 if (!pm_runtime_suspended(dev)) {
1741 ret = atmel_spi_runtime_resume(dev);
1742 if (ret)
1743 return ret;
1744 }
1745
1746 /* Start the queue running */
1747 ret = spi_master_resume(master);
1748 if (ret)
1749 dev_err(dev, "problem starting queue (%d)\n", ret);
1750
1751 return ret;
1752 }
1753 #endif
1754
1755 static const struct dev_pm_ops atmel_spi_pm_ops = {
1756 SET_SYSTEM_SLEEP_PM_OPS(atmel_spi_suspend, atmel_spi_resume)
1757 SET_RUNTIME_PM_OPS(atmel_spi_runtime_suspend,
1758 atmel_spi_runtime_resume, NULL)
1759 };
1760 #define ATMEL_SPI_PM_OPS (&atmel_spi_pm_ops)
1761 #else
1762 #define ATMEL_SPI_PM_OPS NULL
1763 #endif
1764
1765 #if defined(CONFIG_OF)
1766 static const struct of_device_id atmel_spi_dt_ids[] = {
1767 { .compatible = "atmel,at91rm9200-spi" },
1768 { /* sentinel */ }
1769 };
1770
1771 MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
1772 #endif
1773
1774 static struct platform_driver atmel_spi_driver = {
1775 .driver = {
1776 .name = "atmel_spi",
1777 .pm = ATMEL_SPI_PM_OPS,
1778 .of_match_table = of_match_ptr(atmel_spi_dt_ids),
1779 },
1780 .probe = atmel_spi_probe,
1781 .remove = atmel_spi_remove,
1782 };
1783 module_platform_driver(atmel_spi_driver);
1784
1785 MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver");
1786 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1787 MODULE_LICENSE("GPL");
1788 MODULE_ALIAS("platform:atmel_spi");
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