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/of_gpio.h>
28 #include <linux/pinctrl/consumer.h>
29 #include <linux/pm_runtime.h>
30
31 /* SPI register offsets */
32 #define SPI_CR 0x0000
33 #define SPI_MR 0x0004
34 #define SPI_RDR 0x0008
35 #define SPI_TDR 0x000c
36 #define SPI_SR 0x0010
37 #define SPI_IER 0x0014
38 #define SPI_IDR 0x0018
39 #define SPI_IMR 0x001c
40 #define SPI_CSR0 0x0030
41 #define SPI_CSR1 0x0034
42 #define SPI_CSR2 0x0038
43 #define SPI_CSR3 0x003c
44 #define SPI_FMR 0x0040
45 #define SPI_FLR 0x0044
46 #define SPI_VERSION 0x00fc
47 #define SPI_RPR 0x0100
48 #define SPI_RCR 0x0104
49 #define SPI_TPR 0x0108
50 #define SPI_TCR 0x010c
51 #define SPI_RNPR 0x0110
52 #define SPI_RNCR 0x0114
53 #define SPI_TNPR 0x0118
54 #define SPI_TNCR 0x011c
55 #define SPI_PTCR 0x0120
56 #define SPI_PTSR 0x0124
57
58 /* Bitfields in CR */
59 #define SPI_SPIEN_OFFSET 0
60 #define SPI_SPIEN_SIZE 1
61 #define SPI_SPIDIS_OFFSET 1
62 #define SPI_SPIDIS_SIZE 1
63 #define SPI_SWRST_OFFSET 7
64 #define SPI_SWRST_SIZE 1
65 #define SPI_LASTXFER_OFFSET 24
66 #define SPI_LASTXFER_SIZE 1
67 #define SPI_TXFCLR_OFFSET 16
68 #define SPI_TXFCLR_SIZE 1
69 #define SPI_RXFCLR_OFFSET 17
70 #define SPI_RXFCLR_SIZE 1
71 #define SPI_FIFOEN_OFFSET 30
72 #define SPI_FIFOEN_SIZE 1
73 #define SPI_FIFODIS_OFFSET 31
74 #define SPI_FIFODIS_SIZE 1
75
76 /* Bitfields in MR */
77 #define SPI_MSTR_OFFSET 0
78 #define SPI_MSTR_SIZE 1
79 #define SPI_PS_OFFSET 1
80 #define SPI_PS_SIZE 1
81 #define SPI_PCSDEC_OFFSET 2
82 #define SPI_PCSDEC_SIZE 1
83 #define SPI_FDIV_OFFSET 3
84 #define SPI_FDIV_SIZE 1
85 #define SPI_MODFDIS_OFFSET 4
86 #define SPI_MODFDIS_SIZE 1
87 #define SPI_WDRBT_OFFSET 5
88 #define SPI_WDRBT_SIZE 1
89 #define SPI_LLB_OFFSET 7
90 #define SPI_LLB_SIZE 1
91 #define SPI_PCS_OFFSET 16
92 #define SPI_PCS_SIZE 4
93 #define SPI_DLYBCS_OFFSET 24
94 #define SPI_DLYBCS_SIZE 8
95
96 /* Bitfields in RDR */
97 #define SPI_RD_OFFSET 0
98 #define SPI_RD_SIZE 16
99
100 /* Bitfields in TDR */
101 #define SPI_TD_OFFSET 0
102 #define SPI_TD_SIZE 16
103
104 /* Bitfields in SR */
105 #define SPI_RDRF_OFFSET 0
106 #define SPI_RDRF_SIZE 1
107 #define SPI_TDRE_OFFSET 1
108 #define SPI_TDRE_SIZE 1
109 #define SPI_MODF_OFFSET 2
110 #define SPI_MODF_SIZE 1
111 #define SPI_OVRES_OFFSET 3
112 #define SPI_OVRES_SIZE 1
113 #define SPI_ENDRX_OFFSET 4
114 #define SPI_ENDRX_SIZE 1
115 #define SPI_ENDTX_OFFSET 5
116 #define SPI_ENDTX_SIZE 1
117 #define SPI_RXBUFF_OFFSET 6
118 #define SPI_RXBUFF_SIZE 1
119 #define SPI_TXBUFE_OFFSET 7
120 #define SPI_TXBUFE_SIZE 1
121 #define SPI_NSSR_OFFSET 8
122 #define SPI_NSSR_SIZE 1
123 #define SPI_TXEMPTY_OFFSET 9
124 #define SPI_TXEMPTY_SIZE 1
125 #define SPI_SPIENS_OFFSET 16
126 #define SPI_SPIENS_SIZE 1
127 #define SPI_TXFEF_OFFSET 24
128 #define SPI_TXFEF_SIZE 1
129 #define SPI_TXFFF_OFFSET 25
130 #define SPI_TXFFF_SIZE 1
131 #define SPI_TXFTHF_OFFSET 26
132 #define SPI_TXFTHF_SIZE 1
133 #define SPI_RXFEF_OFFSET 27
134 #define SPI_RXFEF_SIZE 1
135 #define SPI_RXFFF_OFFSET 28
136 #define SPI_RXFFF_SIZE 1
137 #define SPI_RXFTHF_OFFSET 29
138 #define SPI_RXFTHF_SIZE 1
139 #define SPI_TXFPTEF_OFFSET 30
140 #define SPI_TXFPTEF_SIZE 1
141 #define SPI_RXFPTEF_OFFSET 31
142 #define SPI_RXFPTEF_SIZE 1
143
144 /* Bitfields in CSR0 */
145 #define SPI_CPOL_OFFSET 0
146 #define SPI_CPOL_SIZE 1
147 #define SPI_NCPHA_OFFSET 1
148 #define SPI_NCPHA_SIZE 1
149 #define SPI_CSAAT_OFFSET 3
150 #define SPI_CSAAT_SIZE 1
151 #define SPI_BITS_OFFSET 4
152 #define SPI_BITS_SIZE 4
153 #define SPI_SCBR_OFFSET 8
154 #define SPI_SCBR_SIZE 8
155 #define SPI_DLYBS_OFFSET 16
156 #define SPI_DLYBS_SIZE 8
157 #define SPI_DLYBCT_OFFSET 24
158 #define SPI_DLYBCT_SIZE 8
159
160 /* Bitfields in RCR */
161 #define SPI_RXCTR_OFFSET 0
162 #define SPI_RXCTR_SIZE 16
163
164 /* Bitfields in TCR */
165 #define SPI_TXCTR_OFFSET 0
166 #define SPI_TXCTR_SIZE 16
167
168 /* Bitfields in RNCR */
169 #define SPI_RXNCR_OFFSET 0
170 #define SPI_RXNCR_SIZE 16
171
172 /* Bitfields in TNCR */
173 #define SPI_TXNCR_OFFSET 0
174 #define SPI_TXNCR_SIZE 16
175
176 /* Bitfields in PTCR */
177 #define SPI_RXTEN_OFFSET 0
178 #define SPI_RXTEN_SIZE 1
179 #define SPI_RXTDIS_OFFSET 1
180 #define SPI_RXTDIS_SIZE 1
181 #define SPI_TXTEN_OFFSET 8
182 #define SPI_TXTEN_SIZE 1
183 #define SPI_TXTDIS_OFFSET 9
184 #define SPI_TXTDIS_SIZE 1
185
186 /* Bitfields in FMR */
187 #define SPI_TXRDYM_OFFSET 0
188 #define SPI_TXRDYM_SIZE 2
189 #define SPI_RXRDYM_OFFSET 4
190 #define SPI_RXRDYM_SIZE 2
191 #define SPI_TXFTHRES_OFFSET 16
192 #define SPI_TXFTHRES_SIZE 6
193 #define SPI_RXFTHRES_OFFSET 24
194 #define SPI_RXFTHRES_SIZE 6
195
196 /* Bitfields in FLR */
197 #define SPI_TXFL_OFFSET 0
198 #define SPI_TXFL_SIZE 6
199 #define SPI_RXFL_OFFSET 16
200 #define SPI_RXFL_SIZE 6
201
202 /* Constants for BITS */
203 #define SPI_BITS_8_BPT 0
204 #define SPI_BITS_9_BPT 1
205 #define SPI_BITS_10_BPT 2
206 #define SPI_BITS_11_BPT 3
207 #define SPI_BITS_12_BPT 4
208 #define SPI_BITS_13_BPT 5
209 #define SPI_BITS_14_BPT 6
210 #define SPI_BITS_15_BPT 7
211 #define SPI_BITS_16_BPT 8
212 #define SPI_ONE_DATA 0
213 #define SPI_TWO_DATA 1
214 #define SPI_FOUR_DATA 2
215
216 /* Bit manipulation macros */
217 #define SPI_BIT(name) \
218 (1 << SPI_##name##_OFFSET)
219 #define SPI_BF(name, value) \
220 (((value) & ((1 << SPI_##name##_SIZE) - 1)) << SPI_##name##_OFFSET)
221 #define SPI_BFEXT(name, value) \
222 (((value) >> SPI_##name##_OFFSET) & ((1 << SPI_##name##_SIZE) - 1))
223 #define SPI_BFINS(name, value, old) \
224 (((old) & ~(((1 << SPI_##name##_SIZE) - 1) << SPI_##name##_OFFSET)) \
225 | SPI_BF(name, value))
226
227 /* Register access macros */
228 #ifdef CONFIG_AVR32
229 #define spi_readl(port, reg) \
230 __raw_readl((port)->regs + SPI_##reg)
231 #define spi_writel(port, reg, value) \
232 __raw_writel((value), (port)->regs + SPI_##reg)
233
234 #define spi_readw(port, reg) \
235 __raw_readw((port)->regs + SPI_##reg)
236 #define spi_writew(port, reg, value) \
237 __raw_writew((value), (port)->regs + SPI_##reg)
238
239 #define spi_readb(port, reg) \
240 __raw_readb((port)->regs + SPI_##reg)
241 #define spi_writeb(port, reg, value) \
242 __raw_writeb((value), (port)->regs + SPI_##reg)
243 #else
244 #define spi_readl(port, reg) \
245 readl_relaxed((port)->regs + SPI_##reg)
246 #define spi_writel(port, reg, value) \
247 writel_relaxed((value), (port)->regs + SPI_##reg)
248
249 #define spi_readw(port, reg) \
250 readw_relaxed((port)->regs + SPI_##reg)
251 #define spi_writew(port, reg, value) \
252 writew_relaxed((value), (port)->regs + SPI_##reg)
253
254 #define spi_readb(port, reg) \
255 readb_relaxed((port)->regs + SPI_##reg)
256 #define spi_writeb(port, reg, value) \
257 writeb_relaxed((value), (port)->regs + SPI_##reg)
258 #endif
259 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
260 * cache operations; better heuristics consider wordsize and bitrate.
261 */
262 #define DMA_MIN_BYTES 16
263
264 #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000))
265
266 #define AUTOSUSPEND_TIMEOUT 2000
267
268 struct atmel_spi_caps {
269 bool is_spi2;
270 bool has_wdrbt;
271 bool has_dma_support;
272 bool has_pdc_support;
273 };
274
275 /*
276 * The core SPI transfer engine just talks to a register bank to set up
277 * DMA transfers; transfer queue progress is driven by IRQs. The clock
278 * framework provides the base clock, subdivided for each spi_device.
279 */
280 struct atmel_spi {
281 spinlock_t lock;
282 unsigned long flags;
283
284 phys_addr_t phybase;
285 void __iomem *regs;
286 int irq;
287 struct clk *clk;
288 struct platform_device *pdev;
289 unsigned long spi_clk;
290
291 struct spi_transfer *current_transfer;
292 int current_remaining_bytes;
293 int done_status;
294 dma_addr_t dma_addr_rx_bbuf;
295 dma_addr_t dma_addr_tx_bbuf;
296 void *addr_rx_bbuf;
297 void *addr_tx_bbuf;
298
299 struct completion xfer_completion;
300
301 struct atmel_spi_caps caps;
302
303 bool use_dma;
304 bool use_pdc;
305 bool use_cs_gpios;
306
307 bool keep_cs;
308 bool cs_active;
309
310 u32 fifo_size;
311 };
312
313 /* Controller-specific per-slave state */
314 struct atmel_spi_device {
315 unsigned int npcs_pin;
316 u32 csr;
317 };
318
319 #define SPI_MAX_DMA_XFER 65535 /* true for both PDC and DMA */
320 #define INVALID_DMA_ADDRESS 0xffffffff
321
322 /*
323 * Version 2 of the SPI controller has
324 * - CR.LASTXFER
325 * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero)
326 * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
327 * - SPI_CSRx.CSAAT
328 * - SPI_CSRx.SBCR allows faster clocking
329 */
atmel_spi_is_v2(struct atmel_spi * as)330 static bool atmel_spi_is_v2(struct atmel_spi *as)
331 {
332 return as->caps.is_spi2;
333 }
334
335 /*
336 * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby
337 * they assume that spi slave device state will not change on deselect, so
338 * that automagic deselection is OK. ("NPCSx rises if no data is to be
339 * transmitted") Not so! Workaround uses nCSx pins as GPIOs; or newer
340 * controllers have CSAAT and friends.
341 *
342 * Since the CSAAT functionality is a bit weird on newer controllers as
343 * well, we use GPIO to control nCSx pins on all controllers, updating
344 * MR.PCS to avoid confusing the controller. Using GPIOs also lets us
345 * support active-high chipselects despite the controller's belief that
346 * only active-low devices/systems exists.
347 *
348 * However, at91rm9200 has a second erratum whereby nCS0 doesn't work
349 * right when driven with GPIO. ("Mode Fault does not allow more than one
350 * Master on Chip Select 0.") No workaround exists for that ... so for
351 * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH,
352 * and (c) will trigger that first erratum in some cases.
353 */
354
cs_activate(struct atmel_spi * as,struct spi_device * spi)355 static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
356 {
357 struct atmel_spi_device *asd = spi->controller_state;
358 unsigned active = spi->mode & SPI_CS_HIGH;
359 u32 mr;
360
361 if (atmel_spi_is_v2(as)) {
362 spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr);
363 /* For the low SPI version, there is a issue that PDC transfer
364 * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS
365 */
366 spi_writel(as, CSR0, asd->csr);
367 if (as->caps.has_wdrbt) {
368 spi_writel(as, MR,
369 SPI_BF(PCS, ~(0x01 << spi->chip_select))
370 | SPI_BIT(WDRBT)
371 | SPI_BIT(MODFDIS)
372 | SPI_BIT(MSTR));
373 } else {
374 spi_writel(as, MR,
375 SPI_BF(PCS, ~(0x01 << spi->chip_select))
376 | SPI_BIT(MODFDIS)
377 | SPI_BIT(MSTR));
378 }
379
380 mr = spi_readl(as, MR);
381 if (as->use_cs_gpios)
382 gpio_set_value(asd->npcs_pin, active);
383 } else {
384 u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0;
385 int i;
386 u32 csr;
387
388 /* Make sure clock polarity is correct */
389 for (i = 0; i < spi->master->num_chipselect; i++) {
390 csr = spi_readl(as, CSR0 + 4 * i);
391 if ((csr ^ cpol) & SPI_BIT(CPOL))
392 spi_writel(as, CSR0 + 4 * i,
393 csr ^ SPI_BIT(CPOL));
394 }
395
396 mr = spi_readl(as, MR);
397 mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr);
398 if (as->use_cs_gpios && spi->chip_select != 0)
399 gpio_set_value(asd->npcs_pin, active);
400 spi_writel(as, MR, mr);
401 }
402
403 dev_dbg(&spi->dev, "activate %u%s, mr %08x\n",
404 asd->npcs_pin, active ? " (high)" : "",
405 mr);
406 }
407
cs_deactivate(struct atmel_spi * as,struct spi_device * spi)408 static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
409 {
410 struct atmel_spi_device *asd = spi->controller_state;
411 unsigned active = spi->mode & SPI_CS_HIGH;
412 u32 mr;
413
414 /* only deactivate *this* device; sometimes transfers to
415 * another device may be active when this routine is called.
416 */
417 mr = spi_readl(as, MR);
418 if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) {
419 mr = SPI_BFINS(PCS, 0xf, mr);
420 spi_writel(as, MR, mr);
421 }
422
423 dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n",
424 asd->npcs_pin, active ? " (low)" : "",
425 mr);
426
427 if (!as->use_cs_gpios)
428 spi_writel(as, CR, SPI_BIT(LASTXFER));
429 else if (atmel_spi_is_v2(as) || spi->chip_select != 0)
430 gpio_set_value(asd->npcs_pin, !active);
431 }
432
atmel_spi_lock(struct atmel_spi * as)433 static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock)
434 {
435 spin_lock_irqsave(&as->lock, as->flags);
436 }
437
atmel_spi_unlock(struct atmel_spi * as)438 static void atmel_spi_unlock(struct atmel_spi *as) __releases(&as->lock)
439 {
440 spin_unlock_irqrestore(&as->lock, as->flags);
441 }
442
atmel_spi_is_vmalloc_xfer(struct spi_transfer * xfer)443 static inline bool atmel_spi_is_vmalloc_xfer(struct spi_transfer *xfer)
444 {
445 return is_vmalloc_addr(xfer->tx_buf) || is_vmalloc_addr(xfer->rx_buf);
446 }
447
atmel_spi_use_dma(struct atmel_spi * as,struct spi_transfer * xfer)448 static inline bool atmel_spi_use_dma(struct atmel_spi *as,
449 struct spi_transfer *xfer)
450 {
451 return as->use_dma && xfer->len >= DMA_MIN_BYTES;
452 }
453
atmel_spi_can_dma(struct spi_master * master,struct spi_device * spi,struct spi_transfer * xfer)454 static bool atmel_spi_can_dma(struct spi_master *master,
455 struct spi_device *spi,
456 struct spi_transfer *xfer)
457 {
458 struct atmel_spi *as = spi_master_get_devdata(master);
459
460 if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5))
461 return atmel_spi_use_dma(as, xfer) &&
462 !atmel_spi_is_vmalloc_xfer(xfer);
463 else
464 return atmel_spi_use_dma(as, xfer);
465
466 }
467
atmel_spi_dma_slave_config(struct atmel_spi * as,struct dma_slave_config * slave_config,u8 bits_per_word)468 static int atmel_spi_dma_slave_config(struct atmel_spi *as,
469 struct dma_slave_config *slave_config,
470 u8 bits_per_word)
471 {
472 struct spi_master *master = platform_get_drvdata(as->pdev);
473 int err = 0;
474
475 if (bits_per_word > 8) {
476 slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
477 slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
478 } else {
479 slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
480 slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
481 }
482
483 slave_config->dst_addr = (dma_addr_t)as->phybase + SPI_TDR;
484 slave_config->src_addr = (dma_addr_t)as->phybase + SPI_RDR;
485 slave_config->src_maxburst = 1;
486 slave_config->dst_maxburst = 1;
487 slave_config->device_fc = false;
488
489 /*
490 * This driver uses fixed peripheral select mode (PS bit set to '0' in
491 * the Mode Register).
492 * So according to the datasheet, when FIFOs are available (and
493 * enabled), the Transmit FIFO operates in Multiple Data Mode.
494 * In this mode, up to 2 data, not 4, can be written into the Transmit
495 * Data Register in a single access.
496 * However, the first data has to be written into the lowest 16 bits and
497 * the second data into the highest 16 bits of the Transmit
498 * Data Register. For 8bit data (the most frequent case), it would
499 * require to rework tx_buf so each data would actualy fit 16 bits.
500 * So we'd rather write only one data at the time. Hence the transmit
501 * path works the same whether FIFOs are available (and enabled) or not.
502 */
503 slave_config->direction = DMA_MEM_TO_DEV;
504 if (dmaengine_slave_config(master->dma_tx, slave_config)) {
505 dev_err(&as->pdev->dev,
506 "failed to configure tx dma channel\n");
507 err = -EINVAL;
508 }
509
510 /*
511 * This driver configures the spi controller for master mode (MSTR bit
512 * set to '1' in the Mode Register).
513 * So according to the datasheet, when FIFOs are available (and
514 * enabled), the Receive FIFO operates in Single Data Mode.
515 * So the receive path works the same whether FIFOs are available (and
516 * enabled) or not.
517 */
518 slave_config->direction = DMA_DEV_TO_MEM;
519 if (dmaengine_slave_config(master->dma_rx, slave_config)) {
520 dev_err(&as->pdev->dev,
521 "failed to configure rx dma channel\n");
522 err = -EINVAL;
523 }
524
525 return err;
526 }
527
atmel_spi_configure_dma(struct spi_master * master,struct atmel_spi * as)528 static int atmel_spi_configure_dma(struct spi_master *master,
529 struct atmel_spi *as)
530 {
531 struct dma_slave_config slave_config;
532 struct device *dev = &as->pdev->dev;
533 int err;
534
535 dma_cap_mask_t mask;
536 dma_cap_zero(mask);
537 dma_cap_set(DMA_SLAVE, mask);
538
539 master->dma_tx = dma_request_slave_channel_reason(dev, "tx");
540 if (IS_ERR(master->dma_tx)) {
541 err = PTR_ERR(master->dma_tx);
542 if (err == -EPROBE_DEFER) {
543 dev_warn(dev, "no DMA channel available at the moment\n");
544 goto error_clear;
545 }
546 dev_err(dev,
547 "DMA TX channel not available, SPI unable to use DMA\n");
548 err = -EBUSY;
549 goto error_clear;
550 }
551
552 /*
553 * No reason to check EPROBE_DEFER here since we have already requested
554 * tx channel. If it fails here, it's for another reason.
555 */
556 master->dma_rx = dma_request_slave_channel(dev, "rx");
557
558 if (!master->dma_rx) {
559 dev_err(dev,
560 "DMA RX channel not available, SPI unable to use DMA\n");
561 err = -EBUSY;
562 goto error;
563 }
564
565 err = atmel_spi_dma_slave_config(as, &slave_config, 8);
566 if (err)
567 goto error;
568
569 dev_info(&as->pdev->dev,
570 "Using %s (tx) and %s (rx) for DMA transfers\n",
571 dma_chan_name(master->dma_tx),
572 dma_chan_name(master->dma_rx));
573
574 return 0;
575 error:
576 if (master->dma_rx)
577 dma_release_channel(master->dma_rx);
578 if (!IS_ERR(master->dma_tx))
579 dma_release_channel(master->dma_tx);
580 error_clear:
581 master->dma_tx = master->dma_rx = NULL;
582 return err;
583 }
584
atmel_spi_stop_dma(struct spi_master * master)585 static void atmel_spi_stop_dma(struct spi_master *master)
586 {
587 if (master->dma_rx)
588 dmaengine_terminate_all(master->dma_rx);
589 if (master->dma_tx)
590 dmaengine_terminate_all(master->dma_tx);
591 }
592
atmel_spi_release_dma(struct spi_master * master)593 static void atmel_spi_release_dma(struct spi_master *master)
594 {
595 if (master->dma_rx) {
596 dma_release_channel(master->dma_rx);
597 master->dma_rx = NULL;
598 }
599 if (master->dma_tx) {
600 dma_release_channel(master->dma_tx);
601 master->dma_tx = NULL;
602 }
603 }
604
605 /* This function is called by the DMA driver from tasklet context */
dma_callback(void * data)606 static void dma_callback(void *data)
607 {
608 struct spi_master *master = data;
609 struct atmel_spi *as = spi_master_get_devdata(master);
610
611 if (is_vmalloc_addr(as->current_transfer->rx_buf) &&
612 IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
613 memcpy(as->current_transfer->rx_buf, as->addr_rx_bbuf,
614 as->current_transfer->len);
615 }
616 complete(&as->xfer_completion);
617 }
618
619 /*
620 * Next transfer using PIO without FIFO.
621 */
atmel_spi_next_xfer_single(struct spi_master * master,struct spi_transfer * xfer)622 static void atmel_spi_next_xfer_single(struct spi_master *master,
623 struct spi_transfer *xfer)
624 {
625 struct atmel_spi *as = spi_master_get_devdata(master);
626 unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;
627
628 dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_pio\n");
629
630 /* Make sure data is not remaining in RDR */
631 spi_readl(as, RDR);
632 while (spi_readl(as, SR) & SPI_BIT(RDRF)) {
633 spi_readl(as, RDR);
634 cpu_relax();
635 }
636
637 if (xfer->bits_per_word > 8)
638 spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos));
639 else
640 spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos));
641
642 dev_dbg(master->dev.parent,
643 " start pio xfer %p: len %u tx %p rx %p bitpw %d\n",
644 xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
645 xfer->bits_per_word);
646
647 /* Enable relevant interrupts */
648 spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES));
649 }
650
651 /*
652 * Next transfer using PIO with FIFO.
653 */
atmel_spi_next_xfer_fifo(struct spi_master * master,struct spi_transfer * xfer)654 static void atmel_spi_next_xfer_fifo(struct spi_master *master,
655 struct spi_transfer *xfer)
656 {
657 struct atmel_spi *as = spi_master_get_devdata(master);
658 u32 current_remaining_data, num_data;
659 u32 offset = xfer->len - as->current_remaining_bytes;
660 const u16 *words = (const u16 *)((u8 *)xfer->tx_buf + offset);
661 const u8 *bytes = (const u8 *)((u8 *)xfer->tx_buf + offset);
662 u16 td0, td1;
663 u32 fifomr;
664
665 dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_fifo\n");
666
667 /* Compute the number of data to transfer in the current iteration */
668 current_remaining_data = ((xfer->bits_per_word > 8) ?
669 ((u32)as->current_remaining_bytes >> 1) :
670 (u32)as->current_remaining_bytes);
671 num_data = min(current_remaining_data, as->fifo_size);
672
673 /* Flush RX and TX FIFOs */
674 spi_writel(as, CR, SPI_BIT(RXFCLR) | SPI_BIT(TXFCLR));
675 while (spi_readl(as, FLR))
676 cpu_relax();
677
678 /* Set RX FIFO Threshold to the number of data to transfer */
679 fifomr = spi_readl(as, FMR);
680 spi_writel(as, FMR, SPI_BFINS(RXFTHRES, num_data, fifomr));
681
682 /* Clear FIFO flags in the Status Register, especially RXFTHF */
683 (void)spi_readl(as, SR);
684
685 /* Fill TX FIFO */
686 while (num_data >= 2) {
687 if (xfer->bits_per_word > 8) {
688 td0 = *words++;
689 td1 = *words++;
690 } else {
691 td0 = *bytes++;
692 td1 = *bytes++;
693 }
694
695 spi_writel(as, TDR, (td1 << 16) | td0);
696 num_data -= 2;
697 }
698
699 if (num_data) {
700 if (xfer->bits_per_word > 8)
701 td0 = *words++;
702 else
703 td0 = *bytes++;
704
705 spi_writew(as, TDR, td0);
706 num_data--;
707 }
708
709 dev_dbg(master->dev.parent,
710 " start fifo xfer %p: len %u tx %p rx %p bitpw %d\n",
711 xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
712 xfer->bits_per_word);
713
714 /*
715 * Enable RX FIFO Threshold Flag interrupt to be notified about
716 * transfer completion.
717 */
718 spi_writel(as, IER, SPI_BIT(RXFTHF) | SPI_BIT(OVRES));
719 }
720
721 /*
722 * Next transfer using PIO.
723 */
atmel_spi_next_xfer_pio(struct spi_master * master,struct spi_transfer * xfer)724 static void atmel_spi_next_xfer_pio(struct spi_master *master,
725 struct spi_transfer *xfer)
726 {
727 struct atmel_spi *as = spi_master_get_devdata(master);
728
729 if (as->fifo_size)
730 atmel_spi_next_xfer_fifo(master, xfer);
731 else
732 atmel_spi_next_xfer_single(master, xfer);
733 }
734
735 /*
736 * Submit next transfer for DMA.
737 */
atmel_spi_next_xfer_dma_submit(struct spi_master * master,struct spi_transfer * xfer,u32 * plen)738 static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
739 struct spi_transfer *xfer,
740 u32 *plen)
741 {
742 struct atmel_spi *as = spi_master_get_devdata(master);
743 struct dma_chan *rxchan = master->dma_rx;
744 struct dma_chan *txchan = master->dma_tx;
745 struct dma_async_tx_descriptor *rxdesc;
746 struct dma_async_tx_descriptor *txdesc;
747 struct dma_slave_config slave_config;
748 dma_cookie_t cookie;
749
750 dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma_submit\n");
751
752 /* Check that the channels are available */
753 if (!rxchan || !txchan)
754 return -ENODEV;
755
756 /* release lock for DMA operations */
757 atmel_spi_unlock(as);
758
759 *plen = xfer->len;
760
761 if (atmel_spi_dma_slave_config(as, &slave_config,
762 xfer->bits_per_word))
763 goto err_exit;
764
765 /* Send both scatterlists */
766 if (atmel_spi_is_vmalloc_xfer(xfer) &&
767 IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
768 rxdesc = dmaengine_prep_slave_single(rxchan,
769 as->dma_addr_rx_bbuf,
770 xfer->len,
771 DMA_DEV_TO_MEM,
772 DMA_PREP_INTERRUPT |
773 DMA_CTRL_ACK);
774 } else {
775 rxdesc = dmaengine_prep_slave_sg(rxchan,
776 xfer->rx_sg.sgl,
777 xfer->rx_sg.nents,
778 DMA_DEV_TO_MEM,
779 DMA_PREP_INTERRUPT |
780 DMA_CTRL_ACK);
781 }
782 if (!rxdesc)
783 goto err_dma;
784
785 if (atmel_spi_is_vmalloc_xfer(xfer) &&
786 IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
787 memcpy(as->addr_tx_bbuf, xfer->tx_buf, xfer->len);
788 txdesc = dmaengine_prep_slave_single(txchan,
789 as->dma_addr_tx_bbuf,
790 xfer->len, DMA_MEM_TO_DEV,
791 DMA_PREP_INTERRUPT |
792 DMA_CTRL_ACK);
793 } else {
794 txdesc = dmaengine_prep_slave_sg(txchan,
795 xfer->tx_sg.sgl,
796 xfer->tx_sg.nents,
797 DMA_MEM_TO_DEV,
798 DMA_PREP_INTERRUPT |
799 DMA_CTRL_ACK);
800 }
801 if (!txdesc)
802 goto err_dma;
803
804 dev_dbg(master->dev.parent,
805 " start dma xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
806 xfer, xfer->len, xfer->tx_buf, (unsigned long long)xfer->tx_dma,
807 xfer->rx_buf, (unsigned long long)xfer->rx_dma);
808
809 /* Enable relevant interrupts */
810 spi_writel(as, IER, SPI_BIT(OVRES));
811
812 /* Put the callback on the RX transfer only, that should finish last */
813 rxdesc->callback = dma_callback;
814 rxdesc->callback_param = master;
815
816 /* Submit and fire RX and TX with TX last so we're ready to read! */
817 cookie = rxdesc->tx_submit(rxdesc);
818 if (dma_submit_error(cookie))
819 goto err_dma;
820 cookie = txdesc->tx_submit(txdesc);
821 if (dma_submit_error(cookie))
822 goto err_dma;
823 rxchan->device->device_issue_pending(rxchan);
824 txchan->device->device_issue_pending(txchan);
825
826 /* take back lock */
827 atmel_spi_lock(as);
828 return 0;
829
830 err_dma:
831 spi_writel(as, IDR, SPI_BIT(OVRES));
832 atmel_spi_stop_dma(master);
833 err_exit:
834 atmel_spi_lock(as);
835 return -ENOMEM;
836 }
837
atmel_spi_next_xfer_data(struct spi_master * master,struct spi_transfer * xfer,dma_addr_t * tx_dma,dma_addr_t * rx_dma,u32 * plen)838 static void atmel_spi_next_xfer_data(struct spi_master *master,
839 struct spi_transfer *xfer,
840 dma_addr_t *tx_dma,
841 dma_addr_t *rx_dma,
842 u32 *plen)
843 {
844 *rx_dma = xfer->rx_dma + xfer->len - *plen;
845 *tx_dma = xfer->tx_dma + xfer->len - *plen;
846 if (*plen > master->max_dma_len)
847 *plen = master->max_dma_len;
848 }
849
atmel_spi_set_xfer_speed(struct atmel_spi * as,struct spi_device * spi,struct spi_transfer * xfer)850 static int atmel_spi_set_xfer_speed(struct atmel_spi *as,
851 struct spi_device *spi,
852 struct spi_transfer *xfer)
853 {
854 u32 scbr, csr;
855 unsigned long bus_hz;
856
857 /* v1 chips start out at half the peripheral bus speed. */
858 bus_hz = as->spi_clk;
859 if (!atmel_spi_is_v2(as))
860 bus_hz /= 2;
861
862 /*
863 * Calculate the lowest divider that satisfies the
864 * constraint, assuming div32/fdiv/mbz == 0.
865 */
866 scbr = DIV_ROUND_UP(bus_hz, xfer->speed_hz);
867
868 /*
869 * If the resulting divider doesn't fit into the
870 * register bitfield, we can't satisfy the constraint.
871 */
872 if (scbr >= (1 << SPI_SCBR_SIZE)) {
873 dev_err(&spi->dev,
874 "setup: %d Hz too slow, scbr %u; min %ld Hz\n",
875 xfer->speed_hz, scbr, bus_hz/255);
876 return -EINVAL;
877 }
878 if (scbr == 0) {
879 dev_err(&spi->dev,
880 "setup: %d Hz too high, scbr %u; max %ld Hz\n",
881 xfer->speed_hz, scbr, bus_hz);
882 return -EINVAL;
883 }
884 csr = spi_readl(as, CSR0 + 4 * spi->chip_select);
885 csr = SPI_BFINS(SCBR, scbr, csr);
886 spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
887
888 return 0;
889 }
890
891 /*
892 * Submit next transfer for PDC.
893 * lock is held, spi irq is blocked
894 */
atmel_spi_pdc_next_xfer(struct spi_master * master,struct spi_message * msg,struct spi_transfer * xfer)895 static void atmel_spi_pdc_next_xfer(struct spi_master *master,
896 struct spi_message *msg,
897 struct spi_transfer *xfer)
898 {
899 struct atmel_spi *as = spi_master_get_devdata(master);
900 u32 len;
901 dma_addr_t tx_dma, rx_dma;
902
903 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
904
905 len = as->current_remaining_bytes;
906 atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
907 as->current_remaining_bytes -= len;
908
909 spi_writel(as, RPR, rx_dma);
910 spi_writel(as, TPR, tx_dma);
911
912 if (msg->spi->bits_per_word > 8)
913 len >>= 1;
914 spi_writel(as, RCR, len);
915 spi_writel(as, TCR, len);
916
917 dev_dbg(&msg->spi->dev,
918 " start xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
919 xfer, xfer->len, xfer->tx_buf,
920 (unsigned long long)xfer->tx_dma, xfer->rx_buf,
921 (unsigned long long)xfer->rx_dma);
922
923 if (as->current_remaining_bytes) {
924 len = as->current_remaining_bytes;
925 atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len);
926 as->current_remaining_bytes -= len;
927
928 spi_writel(as, RNPR, rx_dma);
929 spi_writel(as, TNPR, tx_dma);
930
931 if (msg->spi->bits_per_word > 8)
932 len >>= 1;
933 spi_writel(as, RNCR, len);
934 spi_writel(as, TNCR, len);
935
936 dev_dbg(&msg->spi->dev,
937 " next xfer %p: len %u tx %p/%08llx rx %p/%08llx\n",
938 xfer, xfer->len, xfer->tx_buf,
939 (unsigned long long)xfer->tx_dma, xfer->rx_buf,
940 (unsigned long long)xfer->rx_dma);
941 }
942
943 /* REVISIT: We're waiting for RXBUFF before we start the next
944 * transfer because we need to handle some difficult timing
945 * issues otherwise. If we wait for TXBUFE in one transfer and
946 * then starts waiting for RXBUFF in the next, it's difficult
947 * to tell the difference between the RXBUFF interrupt we're
948 * actually waiting for and the RXBUFF interrupt of the
949 * previous transfer.
950 *
951 * It should be doable, though. Just not now...
952 */
953 spi_writel(as, IER, SPI_BIT(RXBUFF) | SPI_BIT(OVRES));
954 spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN));
955 }
956
957 /*
958 * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma:
959 * - The buffer is either valid for CPU access, else NULL
960 * - If the buffer is valid, so is its DMA address
961 *
962 * This driver manages the dma address unless message->is_dma_mapped.
963 */
964 static int
atmel_spi_dma_map_xfer(struct atmel_spi * as,struct spi_transfer * xfer)965 atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer)
966 {
967 struct device *dev = &as->pdev->dev;
968
969 xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS;
970 if (xfer->tx_buf) {
971 /* tx_buf is a const void* where we need a void * for the dma
972 * mapping */
973 void *nonconst_tx = (void *)xfer->tx_buf;
974
975 xfer->tx_dma = dma_map_single(dev,
976 nonconst_tx, xfer->len,
977 DMA_TO_DEVICE);
978 if (dma_mapping_error(dev, xfer->tx_dma))
979 return -ENOMEM;
980 }
981 if (xfer->rx_buf) {
982 xfer->rx_dma = dma_map_single(dev,
983 xfer->rx_buf, xfer->len,
984 DMA_FROM_DEVICE);
985 if (dma_mapping_error(dev, xfer->rx_dma)) {
986 if (xfer->tx_buf)
987 dma_unmap_single(dev,
988 xfer->tx_dma, xfer->len,
989 DMA_TO_DEVICE);
990 return -ENOMEM;
991 }
992 }
993 return 0;
994 }
995
atmel_spi_dma_unmap_xfer(struct spi_master * master,struct spi_transfer * xfer)996 static void atmel_spi_dma_unmap_xfer(struct spi_master *master,
997 struct spi_transfer *xfer)
998 {
999 if (xfer->tx_dma != INVALID_DMA_ADDRESS)
1000 dma_unmap_single(master->dev.parent, xfer->tx_dma,
1001 xfer->len, DMA_TO_DEVICE);
1002 if (xfer->rx_dma != INVALID_DMA_ADDRESS)
1003 dma_unmap_single(master->dev.parent, xfer->rx_dma,
1004 xfer->len, DMA_FROM_DEVICE);
1005 }
1006
atmel_spi_disable_pdc_transfer(struct atmel_spi * as)1007 static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as)
1008 {
1009 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
1010 }
1011
1012 static void
atmel_spi_pump_single_data(struct atmel_spi * as,struct spi_transfer * xfer)1013 atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer)
1014 {
1015 u8 *rxp;
1016 u16 *rxp16;
1017 unsigned long xfer_pos = xfer->len - as->current_remaining_bytes;
1018
1019 if (xfer->bits_per_word > 8) {
1020 rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos);
1021 *rxp16 = spi_readl(as, RDR);
1022 } else {
1023 rxp = ((u8 *)xfer->rx_buf) + xfer_pos;
1024 *rxp = spi_readl(as, RDR);
1025 }
1026 if (xfer->bits_per_word > 8) {
1027 if (as->current_remaining_bytes > 2)
1028 as->current_remaining_bytes -= 2;
1029 else
1030 as->current_remaining_bytes = 0;
1031 } else {
1032 as->current_remaining_bytes--;
1033 }
1034 }
1035
1036 static void
atmel_spi_pump_fifo_data(struct atmel_spi * as,struct spi_transfer * xfer)1037 atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer)
1038 {
1039 u32 fifolr = spi_readl(as, FLR);
1040 u32 num_bytes, num_data = SPI_BFEXT(RXFL, fifolr);
1041 u32 offset = xfer->len - as->current_remaining_bytes;
1042 u16 *words = (u16 *)((u8 *)xfer->rx_buf + offset);
1043 u8 *bytes = (u8 *)((u8 *)xfer->rx_buf + offset);
1044 u16 rd; /* RD field is the lowest 16 bits of RDR */
1045
1046 /* Update the number of remaining bytes to transfer */
1047 num_bytes = ((xfer->bits_per_word > 8) ?
1048 (num_data << 1) :
1049 num_data);
1050
1051 if (as->current_remaining_bytes > num_bytes)
1052 as->current_remaining_bytes -= num_bytes;
1053 else
1054 as->current_remaining_bytes = 0;
1055
1056 /* Handle odd number of bytes when data are more than 8bit width */
1057 if (xfer->bits_per_word > 8)
1058 as->current_remaining_bytes &= ~0x1;
1059
1060 /* Read data */
1061 while (num_data) {
1062 rd = spi_readl(as, RDR);
1063 if (xfer->bits_per_word > 8)
1064 *words++ = rd;
1065 else
1066 *bytes++ = rd;
1067 num_data--;
1068 }
1069 }
1070
1071 /* Called from IRQ
1072 *
1073 * Must update "current_remaining_bytes" to keep track of data
1074 * to transfer.
1075 */
1076 static void
atmel_spi_pump_pio_data(struct atmel_spi * as,struct spi_transfer * xfer)1077 atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer)
1078 {
1079 if (as->fifo_size)
1080 atmel_spi_pump_fifo_data(as, xfer);
1081 else
1082 atmel_spi_pump_single_data(as, xfer);
1083 }
1084
1085 /* Interrupt
1086 *
1087 * No need for locking in this Interrupt handler: done_status is the
1088 * only information modified.
1089 */
1090 static irqreturn_t
atmel_spi_pio_interrupt(int irq,void * dev_id)1091 atmel_spi_pio_interrupt(int irq, void *dev_id)
1092 {
1093 struct spi_master *master = dev_id;
1094 struct atmel_spi *as = spi_master_get_devdata(master);
1095 u32 status, pending, imr;
1096 struct spi_transfer *xfer;
1097 int ret = IRQ_NONE;
1098
1099 imr = spi_readl(as, IMR);
1100 status = spi_readl(as, SR);
1101 pending = status & imr;
1102
1103 if (pending & SPI_BIT(OVRES)) {
1104 ret = IRQ_HANDLED;
1105 spi_writel(as, IDR, SPI_BIT(OVRES));
1106 dev_warn(master->dev.parent, "overrun\n");
1107
1108 /*
1109 * When we get an overrun, we disregard the current
1110 * transfer. Data will not be copied back from any
1111 * bounce buffer and msg->actual_len will not be
1112 * updated with the last xfer.
1113 *
1114 * We will also not process any remaning transfers in
1115 * the message.
1116 */
1117 as->done_status = -EIO;
1118 smp_wmb();
1119
1120 /* Clear any overrun happening while cleaning up */
1121 spi_readl(as, SR);
1122
1123 complete(&as->xfer_completion);
1124
1125 } else if (pending & (SPI_BIT(RDRF) | SPI_BIT(RXFTHF))) {
1126 atmel_spi_lock(as);
1127
1128 if (as->current_remaining_bytes) {
1129 ret = IRQ_HANDLED;
1130 xfer = as->current_transfer;
1131 atmel_spi_pump_pio_data(as, xfer);
1132 if (!as->current_remaining_bytes)
1133 spi_writel(as, IDR, pending);
1134
1135 complete(&as->xfer_completion);
1136 }
1137
1138 atmel_spi_unlock(as);
1139 } else {
1140 WARN_ONCE(pending, "IRQ not handled, pending = %x\n", pending);
1141 ret = IRQ_HANDLED;
1142 spi_writel(as, IDR, pending);
1143 }
1144
1145 return ret;
1146 }
1147
1148 static irqreturn_t
atmel_spi_pdc_interrupt(int irq,void * dev_id)1149 atmel_spi_pdc_interrupt(int irq, void *dev_id)
1150 {
1151 struct spi_master *master = dev_id;
1152 struct atmel_spi *as = spi_master_get_devdata(master);
1153 u32 status, pending, imr;
1154 int ret = IRQ_NONE;
1155
1156 imr = spi_readl(as, IMR);
1157 status = spi_readl(as, SR);
1158 pending = status & imr;
1159
1160 if (pending & SPI_BIT(OVRES)) {
1161
1162 ret = IRQ_HANDLED;
1163
1164 spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX)
1165 | SPI_BIT(OVRES)));
1166
1167 /* Clear any overrun happening while cleaning up */
1168 spi_readl(as, SR);
1169
1170 as->done_status = -EIO;
1171
1172 complete(&as->xfer_completion);
1173
1174 } else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) {
1175 ret = IRQ_HANDLED;
1176
1177 spi_writel(as, IDR, pending);
1178
1179 complete(&as->xfer_completion);
1180 }
1181
1182 return ret;
1183 }
1184
atmel_spi_setup(struct spi_device * spi)1185 static int atmel_spi_setup(struct spi_device *spi)
1186 {
1187 struct atmel_spi *as;
1188 struct atmel_spi_device *asd;
1189 u32 csr;
1190 unsigned int bits = spi->bits_per_word;
1191 unsigned int npcs_pin;
1192
1193 as = spi_master_get_devdata(spi->master);
1194
1195 /* see notes above re chipselect */
1196 if (!atmel_spi_is_v2(as)
1197 && spi->chip_select == 0
1198 && (spi->mode & SPI_CS_HIGH)) {
1199 dev_dbg(&spi->dev, "setup: can't be active-high\n");
1200 return -EINVAL;
1201 }
1202
1203 csr = SPI_BF(BITS, bits - 8);
1204 if (spi->mode & SPI_CPOL)
1205 csr |= SPI_BIT(CPOL);
1206 if (!(spi->mode & SPI_CPHA))
1207 csr |= SPI_BIT(NCPHA);
1208 if (!as->use_cs_gpios)
1209 csr |= SPI_BIT(CSAAT);
1210
1211 /* DLYBS is mostly irrelevant since we manage chipselect using GPIOs.
1212 *
1213 * DLYBCT would add delays between words, slowing down transfers.
1214 * It could potentially be useful to cope with DMA bottlenecks, but
1215 * in those cases it's probably best to just use a lower bitrate.
1216 */
1217 csr |= SPI_BF(DLYBS, 0);
1218 csr |= SPI_BF(DLYBCT, 0);
1219
1220 /* chipselect must have been muxed as GPIO (e.g. in board setup) */
1221 npcs_pin = (unsigned long)spi->controller_data;
1222
1223 if (!as->use_cs_gpios)
1224 npcs_pin = spi->chip_select;
1225 else if (gpio_is_valid(spi->cs_gpio))
1226 npcs_pin = spi->cs_gpio;
1227
1228 asd = spi->controller_state;
1229 if (!asd) {
1230 asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL);
1231 if (!asd)
1232 return -ENOMEM;
1233
1234 if (as->use_cs_gpios)
1235 gpio_direction_output(npcs_pin,
1236 !(spi->mode & SPI_CS_HIGH));
1237
1238 asd->npcs_pin = npcs_pin;
1239 spi->controller_state = asd;
1240 }
1241
1242 asd->csr = csr;
1243
1244 dev_dbg(&spi->dev,
1245 "setup: bpw %u mode 0x%x -> csr%d %08x\n",
1246 bits, spi->mode, spi->chip_select, csr);
1247
1248 if (!atmel_spi_is_v2(as))
1249 spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
1250
1251 return 0;
1252 }
1253
atmel_spi_one_transfer(struct spi_master * master,struct spi_message * msg,struct spi_transfer * xfer)1254 static int atmel_spi_one_transfer(struct spi_master *master,
1255 struct spi_message *msg,
1256 struct spi_transfer *xfer)
1257 {
1258 struct atmel_spi *as;
1259 struct spi_device *spi = msg->spi;
1260 u8 bits;
1261 u32 len;
1262 struct atmel_spi_device *asd;
1263 int timeout;
1264 int ret;
1265 unsigned long dma_timeout;
1266
1267 as = spi_master_get_devdata(master);
1268
1269 if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
1270 dev_dbg(&spi->dev, "missing rx or tx buf\n");
1271 return -EINVAL;
1272 }
1273
1274 asd = spi->controller_state;
1275 bits = (asd->csr >> 4) & 0xf;
1276 if (bits != xfer->bits_per_word - 8) {
1277 dev_dbg(&spi->dev,
1278 "you can't yet change bits_per_word in transfers\n");
1279 return -ENOPROTOOPT;
1280 }
1281
1282 /*
1283 * DMA map early, for performance (empties dcache ASAP) and
1284 * better fault reporting.
1285 */
1286 if ((!msg->is_dma_mapped)
1287 && as->use_pdc) {
1288 if (atmel_spi_dma_map_xfer(as, xfer) < 0)
1289 return -ENOMEM;
1290 }
1291
1292 atmel_spi_set_xfer_speed(as, msg->spi, xfer);
1293
1294 as->done_status = 0;
1295 as->current_transfer = xfer;
1296 as->current_remaining_bytes = xfer->len;
1297 while (as->current_remaining_bytes) {
1298 reinit_completion(&as->xfer_completion);
1299
1300 if (as->use_pdc) {
1301 atmel_spi_pdc_next_xfer(master, msg, xfer);
1302 } else if (atmel_spi_use_dma(as, xfer)) {
1303 len = as->current_remaining_bytes;
1304 ret = atmel_spi_next_xfer_dma_submit(master,
1305 xfer, &len);
1306 if (ret) {
1307 dev_err(&spi->dev,
1308 "unable to use DMA, fallback to PIO\n");
1309 atmel_spi_next_xfer_pio(master, xfer);
1310 } else {
1311 as->current_remaining_bytes -= len;
1312 if (as->current_remaining_bytes < 0)
1313 as->current_remaining_bytes = 0;
1314 }
1315 } else {
1316 atmel_spi_next_xfer_pio(master, xfer);
1317 }
1318
1319 /* interrupts are disabled, so free the lock for schedule */
1320 atmel_spi_unlock(as);
1321 dma_timeout = wait_for_completion_timeout(&as->xfer_completion,
1322 SPI_DMA_TIMEOUT);
1323 atmel_spi_lock(as);
1324 if (WARN_ON(dma_timeout == 0)) {
1325 dev_err(&spi->dev, "spi transfer timeout\n");
1326 as->done_status = -EIO;
1327 }
1328
1329 if (as->done_status)
1330 break;
1331 }
1332
1333 if (as->done_status) {
1334 if (as->use_pdc) {
1335 dev_warn(master->dev.parent,
1336 "overrun (%u/%u remaining)\n",
1337 spi_readl(as, TCR), spi_readl(as, RCR));
1338
1339 /*
1340 * Clean up DMA registers and make sure the data
1341 * registers are empty.
1342 */
1343 spi_writel(as, RNCR, 0);
1344 spi_writel(as, TNCR, 0);
1345 spi_writel(as, RCR, 0);
1346 spi_writel(as, TCR, 0);
1347 for (timeout = 1000; timeout; timeout--)
1348 if (spi_readl(as, SR) & SPI_BIT(TXEMPTY))
1349 break;
1350 if (!timeout)
1351 dev_warn(master->dev.parent,
1352 "timeout waiting for TXEMPTY");
1353 while (spi_readl(as, SR) & SPI_BIT(RDRF))
1354 spi_readl(as, RDR);
1355
1356 /* Clear any overrun happening while cleaning up */
1357 spi_readl(as, SR);
1358
1359 } else if (atmel_spi_use_dma(as, xfer)) {
1360 atmel_spi_stop_dma(master);
1361 }
1362
1363 if (!msg->is_dma_mapped
1364 && as->use_pdc)
1365 atmel_spi_dma_unmap_xfer(master, xfer);
1366
1367 return 0;
1368
1369 } else {
1370 /* only update length if no error */
1371 msg->actual_length += xfer->len;
1372 }
1373
1374 if (!msg->is_dma_mapped
1375 && as->use_pdc)
1376 atmel_spi_dma_unmap_xfer(master, xfer);
1377
1378 if (xfer->delay_usecs)
1379 udelay(xfer->delay_usecs);
1380
1381 if (xfer->cs_change) {
1382 if (list_is_last(&xfer->transfer_list,
1383 &msg->transfers)) {
1384 as->keep_cs = true;
1385 } else {
1386 as->cs_active = !as->cs_active;
1387 if (as->cs_active)
1388 cs_activate(as, msg->spi);
1389 else
1390 cs_deactivate(as, msg->spi);
1391 }
1392 }
1393
1394 return 0;
1395 }
1396
atmel_spi_transfer_one_message(struct spi_master * master,struct spi_message * msg)1397 static int atmel_spi_transfer_one_message(struct spi_master *master,
1398 struct spi_message *msg)
1399 {
1400 struct atmel_spi *as;
1401 struct spi_transfer *xfer;
1402 struct spi_device *spi = msg->spi;
1403 int ret = 0;
1404
1405 as = spi_master_get_devdata(master);
1406
1407 dev_dbg(&spi->dev, "new message %p submitted for %s\n",
1408 msg, dev_name(&spi->dev));
1409
1410 atmel_spi_lock(as);
1411 cs_activate(as, spi);
1412
1413 as->cs_active = true;
1414 as->keep_cs = false;
1415
1416 msg->status = 0;
1417 msg->actual_length = 0;
1418
1419 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1420 ret = atmel_spi_one_transfer(master, msg, xfer);
1421 if (ret)
1422 goto msg_done;
1423 }
1424
1425 if (as->use_pdc)
1426 atmel_spi_disable_pdc_transfer(as);
1427
1428 list_for_each_entry(xfer, &msg->transfers, transfer_list) {
1429 dev_dbg(&spi->dev,
1430 " xfer %p: len %u tx %p/%pad rx %p/%pad\n",
1431 xfer, xfer->len,
1432 xfer->tx_buf, &xfer->tx_dma,
1433 xfer->rx_buf, &xfer->rx_dma);
1434 }
1435
1436 msg_done:
1437 if (!as->keep_cs)
1438 cs_deactivate(as, msg->spi);
1439
1440 atmel_spi_unlock(as);
1441
1442 msg->status = as->done_status;
1443 spi_finalize_current_message(spi->master);
1444
1445 return ret;
1446 }
1447
atmel_spi_cleanup(struct spi_device * spi)1448 static void atmel_spi_cleanup(struct spi_device *spi)
1449 {
1450 struct atmel_spi_device *asd = spi->controller_state;
1451
1452 if (!asd)
1453 return;
1454
1455 spi->controller_state = NULL;
1456 kfree(asd);
1457 }
1458
atmel_get_version(struct atmel_spi * as)1459 static inline unsigned int atmel_get_version(struct atmel_spi *as)
1460 {
1461 return spi_readl(as, VERSION) & 0x00000fff;
1462 }
1463
atmel_get_caps(struct atmel_spi * as)1464 static void atmel_get_caps(struct atmel_spi *as)
1465 {
1466 unsigned int version;
1467
1468 version = atmel_get_version(as);
1469
1470 as->caps.is_spi2 = version > 0x121;
1471 as->caps.has_wdrbt = version >= 0x210;
1472 as->caps.has_dma_support = version >= 0x212;
1473 as->caps.has_pdc_support = version < 0x212;
1474 }
1475
1476 /*-------------------------------------------------------------------------*/
atmel_spi_gpio_cs(struct platform_device * pdev)1477 static int atmel_spi_gpio_cs(struct platform_device *pdev)
1478 {
1479 struct spi_master *master = platform_get_drvdata(pdev);
1480 struct atmel_spi *as = spi_master_get_devdata(master);
1481 struct device_node *np = master->dev.of_node;
1482 int i;
1483 int ret = 0;
1484 int nb = 0;
1485
1486 if (!as->use_cs_gpios)
1487 return 0;
1488
1489 if (!np)
1490 return 0;
1491
1492 nb = of_gpio_named_count(np, "cs-gpios");
1493 for (i = 0; i < nb; i++) {
1494 int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
1495 "cs-gpios", i);
1496
1497 if (cs_gpio == -EPROBE_DEFER)
1498 return cs_gpio;
1499
1500 if (gpio_is_valid(cs_gpio)) {
1501 ret = devm_gpio_request(&pdev->dev, cs_gpio,
1502 dev_name(&pdev->dev));
1503 if (ret)
1504 return ret;
1505 }
1506 }
1507
1508 return 0;
1509 }
1510
atmel_spi_init(struct atmel_spi * as)1511 static void atmel_spi_init(struct atmel_spi *as)
1512 {
1513 spi_writel(as, CR, SPI_BIT(SWRST));
1514 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
1515
1516 /* It is recommended to enable FIFOs first thing after reset */
1517 if (as->fifo_size)
1518 spi_writel(as, CR, SPI_BIT(FIFOEN));
1519
1520 if (as->caps.has_wdrbt) {
1521 spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS)
1522 | SPI_BIT(MSTR));
1523 } else {
1524 spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
1525 }
1526
1527 if (as->use_pdc)
1528 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
1529 spi_writel(as, CR, SPI_BIT(SPIEN));
1530 }
1531
atmel_spi_probe(struct platform_device * pdev)1532 static int atmel_spi_probe(struct platform_device *pdev)
1533 {
1534 struct resource *regs;
1535 int irq;
1536 struct clk *clk;
1537 int ret;
1538 struct spi_master *master;
1539 struct atmel_spi *as;
1540
1541 /* Select default pin state */
1542 pinctrl_pm_select_default_state(&pdev->dev);
1543
1544 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1545 if (!regs)
1546 return -ENXIO;
1547
1548 irq = platform_get_irq(pdev, 0);
1549 if (irq < 0)
1550 return irq;
1551
1552 clk = devm_clk_get(&pdev->dev, "spi_clk");
1553 if (IS_ERR(clk))
1554 return PTR_ERR(clk);
1555
1556 /* setup spi core then atmel-specific driver state */
1557 ret = -ENOMEM;
1558 master = spi_alloc_master(&pdev->dev, sizeof(*as));
1559 if (!master)
1560 goto out_free;
1561
1562 /* the spi->mode bits understood by this driver: */
1563 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1564 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16);
1565 master->dev.of_node = pdev->dev.of_node;
1566 master->bus_num = pdev->id;
1567 master->num_chipselect = master->dev.of_node ? 0 : 4;
1568 master->setup = atmel_spi_setup;
1569 master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
1570 master->transfer_one_message = atmel_spi_transfer_one_message;
1571 master->cleanup = atmel_spi_cleanup;
1572 master->auto_runtime_pm = true;
1573 master->max_dma_len = SPI_MAX_DMA_XFER;
1574 master->can_dma = atmel_spi_can_dma;
1575 platform_set_drvdata(pdev, master);
1576
1577 as = spi_master_get_devdata(master);
1578
1579 spin_lock_init(&as->lock);
1580
1581 as->pdev = pdev;
1582 as->regs = devm_ioremap_resource(&pdev->dev, regs);
1583 if (IS_ERR(as->regs)) {
1584 ret = PTR_ERR(as->regs);
1585 goto out_unmap_regs;
1586 }
1587 as->phybase = regs->start;
1588 as->irq = irq;
1589 as->clk = clk;
1590
1591 init_completion(&as->xfer_completion);
1592
1593 atmel_get_caps(as);
1594
1595 as->use_cs_gpios = true;
1596 if (atmel_spi_is_v2(as) &&
1597 pdev->dev.of_node &&
1598 !of_get_property(pdev->dev.of_node, "cs-gpios", NULL)) {
1599 as->use_cs_gpios = false;
1600 master->num_chipselect = 4;
1601 }
1602
1603 ret = atmel_spi_gpio_cs(pdev);
1604 if (ret)
1605 goto out_unmap_regs;
1606
1607 as->use_dma = false;
1608 as->use_pdc = false;
1609 if (as->caps.has_dma_support) {
1610 ret = atmel_spi_configure_dma(master, as);
1611 if (ret == 0) {
1612 as->use_dma = true;
1613 } else if (ret == -EPROBE_DEFER) {
1614 return ret;
1615 }
1616 } else if (as->caps.has_pdc_support) {
1617 as->use_pdc = true;
1618 }
1619
1620 if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
1621 as->addr_rx_bbuf = dma_alloc_coherent(&pdev->dev,
1622 SPI_MAX_DMA_XFER,
1623 &as->dma_addr_rx_bbuf,
1624 GFP_KERNEL | GFP_DMA);
1625 if (!as->addr_rx_bbuf) {
1626 as->use_dma = false;
1627 } else {
1628 as->addr_tx_bbuf = dma_alloc_coherent(&pdev->dev,
1629 SPI_MAX_DMA_XFER,
1630 &as->dma_addr_tx_bbuf,
1631 GFP_KERNEL | GFP_DMA);
1632 if (!as->addr_tx_bbuf) {
1633 as->use_dma = false;
1634 dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER,
1635 as->addr_rx_bbuf,
1636 as->dma_addr_rx_bbuf);
1637 }
1638 }
1639 if (!as->use_dma)
1640 dev_info(master->dev.parent,
1641 " can not allocate dma coherent memory\n");
1642 }
1643
1644 if (as->caps.has_dma_support && !as->use_dma)
1645 dev_info(&pdev->dev, "Atmel SPI Controller using PIO only\n");
1646
1647 if (as->use_pdc) {
1648 ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pdc_interrupt,
1649 0, dev_name(&pdev->dev), master);
1650 } else {
1651 ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pio_interrupt,
1652 0, dev_name(&pdev->dev), master);
1653 }
1654 if (ret)
1655 goto out_unmap_regs;
1656
1657 /* Initialize the hardware */
1658 ret = clk_prepare_enable(clk);
1659 if (ret)
1660 goto out_free_irq;
1661
1662 as->spi_clk = clk_get_rate(clk);
1663
1664 as->fifo_size = 0;
1665 if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size",
1666 &as->fifo_size)) {
1667 dev_info(&pdev->dev, "Using FIFO (%u data)\n", as->fifo_size);
1668 }
1669
1670 atmel_spi_init(as);
1671
1672 pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT);
1673 pm_runtime_use_autosuspend(&pdev->dev);
1674 pm_runtime_set_active(&pdev->dev);
1675 pm_runtime_enable(&pdev->dev);
1676
1677 ret = devm_spi_register_master(&pdev->dev, master);
1678 if (ret)
1679 goto out_free_dma;
1680
1681 /* go! */
1682 dev_info(&pdev->dev, "Atmel SPI Controller version 0x%x at 0x%08lx (irq %d)\n",
1683 atmel_get_version(as), (unsigned long)regs->start,
1684 irq);
1685
1686 return 0;
1687
1688 out_free_dma:
1689 pm_runtime_disable(&pdev->dev);
1690 pm_runtime_set_suspended(&pdev->dev);
1691
1692 if (as->use_dma)
1693 atmel_spi_release_dma(master);
1694
1695 spi_writel(as, CR, SPI_BIT(SWRST));
1696 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
1697 clk_disable_unprepare(clk);
1698 out_free_irq:
1699 out_unmap_regs:
1700 out_free:
1701 spi_master_put(master);
1702 return ret;
1703 }
1704
atmel_spi_remove(struct platform_device * pdev)1705 static int atmel_spi_remove(struct platform_device *pdev)
1706 {
1707 struct spi_master *master = platform_get_drvdata(pdev);
1708 struct atmel_spi *as = spi_master_get_devdata(master);
1709
1710 pm_runtime_get_sync(&pdev->dev);
1711
1712 /* reset the hardware and block queue progress */
1713 if (as->use_dma) {
1714 atmel_spi_stop_dma(master);
1715 atmel_spi_release_dma(master);
1716 if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) {
1717 dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER,
1718 as->addr_tx_bbuf,
1719 as->dma_addr_tx_bbuf);
1720 dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER,
1721 as->addr_rx_bbuf,
1722 as->dma_addr_rx_bbuf);
1723 }
1724 }
1725
1726 spin_lock_irq(&as->lock);
1727 spi_writel(as, CR, SPI_BIT(SWRST));
1728 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
1729 spi_readl(as, SR);
1730 spin_unlock_irq(&as->lock);
1731
1732 clk_disable_unprepare(as->clk);
1733
1734 pm_runtime_put_noidle(&pdev->dev);
1735 pm_runtime_disable(&pdev->dev);
1736
1737 return 0;
1738 }
1739
1740 #ifdef CONFIG_PM
atmel_spi_runtime_suspend(struct device * dev)1741 static int atmel_spi_runtime_suspend(struct device *dev)
1742 {
1743 struct spi_master *master = dev_get_drvdata(dev);
1744 struct atmel_spi *as = spi_master_get_devdata(master);
1745
1746 clk_disable_unprepare(as->clk);
1747 pinctrl_pm_select_sleep_state(dev);
1748
1749 return 0;
1750 }
1751
atmel_spi_runtime_resume(struct device * dev)1752 static int atmel_spi_runtime_resume(struct device *dev)
1753 {
1754 struct spi_master *master = dev_get_drvdata(dev);
1755 struct atmel_spi *as = spi_master_get_devdata(master);
1756
1757 pinctrl_pm_select_default_state(dev);
1758
1759 return clk_prepare_enable(as->clk);
1760 }
1761
1762 #ifdef CONFIG_PM_SLEEP
atmel_spi_suspend(struct device * dev)1763 static int atmel_spi_suspend(struct device *dev)
1764 {
1765 struct spi_master *master = dev_get_drvdata(dev);
1766 int ret;
1767
1768 /* Stop the queue running */
1769 ret = spi_master_suspend(master);
1770 if (ret) {
1771 dev_warn(dev, "cannot suspend master\n");
1772 return ret;
1773 }
1774
1775 if (!pm_runtime_suspended(dev))
1776 atmel_spi_runtime_suspend(dev);
1777
1778 return 0;
1779 }
1780
atmel_spi_resume(struct device * dev)1781 static int atmel_spi_resume(struct device *dev)
1782 {
1783 struct spi_master *master = dev_get_drvdata(dev);
1784 struct atmel_spi *as = spi_master_get_devdata(master);
1785 int ret;
1786
1787 ret = clk_prepare_enable(as->clk);
1788 if (ret)
1789 return ret;
1790
1791 atmel_spi_init(as);
1792
1793 clk_disable_unprepare(as->clk);
1794
1795 if (!pm_runtime_suspended(dev)) {
1796 ret = atmel_spi_runtime_resume(dev);
1797 if (ret)
1798 return ret;
1799 }
1800
1801 /* Start the queue running */
1802 ret = spi_master_resume(master);
1803 if (ret)
1804 dev_err(dev, "problem starting queue (%d)\n", ret);
1805
1806 return ret;
1807 }
1808 #endif
1809
1810 static const struct dev_pm_ops atmel_spi_pm_ops = {
1811 SET_SYSTEM_SLEEP_PM_OPS(atmel_spi_suspend, atmel_spi_resume)
1812 SET_RUNTIME_PM_OPS(atmel_spi_runtime_suspend,
1813 atmel_spi_runtime_resume, NULL)
1814 };
1815 #define ATMEL_SPI_PM_OPS (&atmel_spi_pm_ops)
1816 #else
1817 #define ATMEL_SPI_PM_OPS NULL
1818 #endif
1819
1820 #if defined(CONFIG_OF)
1821 static const struct of_device_id atmel_spi_dt_ids[] = {
1822 { .compatible = "atmel,at91rm9200-spi" },
1823 { /* sentinel */ }
1824 };
1825
1826 MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
1827 #endif
1828
1829 static struct platform_driver atmel_spi_driver = {
1830 .driver = {
1831 .name = "atmel_spi",
1832 .pm = ATMEL_SPI_PM_OPS,
1833 .of_match_table = of_match_ptr(atmel_spi_dt_ids),
1834 },
1835 .probe = atmel_spi_probe,
1836 .remove = atmel_spi_remove,
1837 };
1838 module_platform_driver(atmel_spi_driver);
1839
1840 MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver");
1841 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
1842 MODULE_LICENSE("GPL");
1843 MODULE_ALIAS("platform:atmel_spi");
1844
