projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge tag 'armsoc-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[deliverable/linux.git] / drivers / spi / spi-pxa2xx.c
1 /*
2 * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
3 * Copyright (C) 2013, Intel Corporation
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 #include <linux/ioport.h>
20 #include <linux/errno.h>
21 #include <linux/err.h>
22 #include <linux/interrupt.h>
23 #include <linux/kernel.h>
24 #include <linux/platform_device.h>
25 #include <linux/spi/pxa2xx_spi.h>
26 #include <linux/spi/spi.h>
27 #include <linux/delay.h>
28 #include <linux/gpio.h>
29 #include <linux/slab.h>
30 #include <linux/clk.h>
31 #include <linux/pm_runtime.h>
32 #include <linux/acpi.h>
33
34 #include "spi-pxa2xx.h"
35
36 MODULE_AUTHOR("Stephen Street");
37 MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
38 MODULE_LICENSE("GPL");
39 MODULE_ALIAS("platform:pxa2xx-spi");
40
41 #define TIMOUT_DFLT 1000
42
43 /*
44 * for testing SSCR1 changes that require SSP restart, basically
45 * everything except the service and interrupt enables, the pxa270 developer
46 * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
47 * list, but the PXA255 dev man says all bits without really meaning the
48 * service and interrupt enables
49 */
50 #define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
51 | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
52 | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
53 | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
54 | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
55 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
56
57 #define QUARK_X1000_SSCR1_CHANGE_MASK (QUARK_X1000_SSCR1_STRF \
58 | QUARK_X1000_SSCR1_EFWR \
59 | QUARK_X1000_SSCR1_RFT \
60 | QUARK_X1000_SSCR1_TFT \
61 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
62
63 #define LPSS_RX_THRESH_DFLT 64
64 #define LPSS_TX_LOTHRESH_DFLT 160
65 #define LPSS_TX_HITHRESH_DFLT 224
66
67 /* Offset from drv_data->lpss_base */
68 #define GENERAL_REG 0x08
69 #define GENERAL_REG_RXTO_HOLDOFF_DISABLE BIT(24)
70 #define SSP_REG 0x0c
71 #define SPI_CS_CONTROL 0x18
72 #define SPI_CS_CONTROL_SW_MODE BIT(0)
73 #define SPI_CS_CONTROL_CS_HIGH BIT(1)
74
75 static bool is_lpss_ssp(const struct driver_data *drv_data)
76 {
77 return drv_data->ssp_type == LPSS_SSP;
78 }
79
80 static bool is_quark_x1000_ssp(const struct driver_data *drv_data)
81 {
82 return drv_data->ssp_type == QUARK_X1000_SSP;
83 }
84
85 static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
86 {
87 switch (drv_data->ssp_type) {
88 case QUARK_X1000_SSP:
89 return QUARK_X1000_SSCR1_CHANGE_MASK;
90 default:
91 return SSCR1_CHANGE_MASK;
92 }
93 }
94
95 static u32
96 pxa2xx_spi_get_rx_default_thre(const struct driver_data *drv_data)
97 {
98 switch (drv_data->ssp_type) {
99 case QUARK_X1000_SSP:
100 return RX_THRESH_QUARK_X1000_DFLT;
101 default:
102 return RX_THRESH_DFLT;
103 }
104 }
105
106 static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
107 {
108 u32 mask;
109
110 switch (drv_data->ssp_type) {
111 case QUARK_X1000_SSP:
112 mask = QUARK_X1000_SSSR_TFL_MASK;
113 break;
114 default:
115 mask = SSSR_TFL_MASK;
116 break;
117 }
118
119 return (pxa2xx_spi_read(drv_data, SSSR) & mask) == mask;
120 }
121
122 static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
123 u32 *sccr1_reg)
124 {
125 u32 mask;
126
127 switch (drv_data->ssp_type) {
128 case QUARK_X1000_SSP:
129 mask = QUARK_X1000_SSCR1_RFT;
130 break;
131 default:
132 mask = SSCR1_RFT;
133 break;
134 }
135 *sccr1_reg &= ~mask;
136 }
137
138 static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
139 u32 *sccr1_reg, u32 threshold)
140 {
141 switch (drv_data->ssp_type) {
142 case QUARK_X1000_SSP:
143 *sccr1_reg |= QUARK_X1000_SSCR1_RxTresh(threshold);
144 break;
145 default:
146 *sccr1_reg |= SSCR1_RxTresh(threshold);
147 break;
148 }
149 }
150
151 static u32 pxa2xx_configure_sscr0(const struct driver_data *drv_data,
152 u32 clk_div, u8 bits)
153 {
154 switch (drv_data->ssp_type) {
155 case QUARK_X1000_SSP:
156 return clk_div
157 | QUARK_X1000_SSCR0_Motorola
158 | QUARK_X1000_SSCR0_DataSize(bits > 32 ? 8 : bits)
159 | SSCR0_SSE;
160 default:
161 return clk_div
162 | SSCR0_Motorola
163 | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
164 | SSCR0_SSE
165 | (bits > 16 ? SSCR0_EDSS : 0);
166 }
167 }
168
169 /*
170 * Read and write LPSS SSP private registers. Caller must first check that
171 * is_lpss_ssp() returns true before these can be called.
172 */
173 static u32 __lpss_ssp_read_priv(struct driver_data *drv_data, unsigned offset)
174 {
175 WARN_ON(!drv_data->lpss_base);
176 return readl(drv_data->lpss_base + offset);
177 }
178
179 static void __lpss_ssp_write_priv(struct driver_data *drv_data,
180 unsigned offset, u32 value)
181 {
182 WARN_ON(!drv_data->lpss_base);
183 writel(value, drv_data->lpss_base + offset);
184 }
185
186 /*
187 * lpss_ssp_setup - perform LPSS SSP specific setup
188 * @drv_data: pointer to the driver private data
189 *
190 * Perform LPSS SSP specific setup. This function must be called first if
191 * one is going to use LPSS SSP private registers.
192 */
193 static void lpss_ssp_setup(struct driver_data *drv_data)
194 {
195 unsigned offset = 0x400;
196 u32 value, orig;
197
198 /*
199 * Perform auto-detection of the LPSS SSP private registers. They
200 * can be either at 1k or 2k offset from the base address.
201 */
202 orig = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
203
204 /* Test SPI_CS_CONTROL_SW_MODE bit enabling */
205 value = orig | SPI_CS_CONTROL_SW_MODE;
206 writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL);
207 value = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
208 if (value != (orig | SPI_CS_CONTROL_SW_MODE)) {
209 offset = 0x800;
210 goto detection_done;
211 }
212
213 orig = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
214
215 /* Test SPI_CS_CONTROL_SW_MODE bit disabling */
216 value = orig & ~SPI_CS_CONTROL_SW_MODE;
217 writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL);
218 value = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
219 if (value != (orig & ~SPI_CS_CONTROL_SW_MODE)) {
220 offset = 0x800;
221 goto detection_done;
222 }
223
224 detection_done:
225 /* Now set the LPSS base */
226 drv_data->lpss_base = drv_data->ioaddr + offset;
227
228 /* Enable software chip select control */
229 value = SPI_CS_CONTROL_SW_MODE | SPI_CS_CONTROL_CS_HIGH;
230 __lpss_ssp_write_priv(drv_data, SPI_CS_CONTROL, value);
231
232 /* Enable multiblock DMA transfers */
233 if (drv_data->master_info->enable_dma) {
234 __lpss_ssp_write_priv(drv_data, SSP_REG, 1);
235
236 value = __lpss_ssp_read_priv(drv_data, GENERAL_REG);
237 value |= GENERAL_REG_RXTO_HOLDOFF_DISABLE;
238 __lpss_ssp_write_priv(drv_data, GENERAL_REG, value);
239 }
240 }
241
242 static void lpss_ssp_cs_control(struct driver_data *drv_data, bool enable)
243 {
244 u32 value;
245
246 value = __lpss_ssp_read_priv(drv_data, SPI_CS_CONTROL);
247 if (enable)
248 value &= ~SPI_CS_CONTROL_CS_HIGH;
249 else
250 value |= SPI_CS_CONTROL_CS_HIGH;
251 __lpss_ssp_write_priv(drv_data, SPI_CS_CONTROL, value);
252 }
253
254 static void cs_assert(struct driver_data *drv_data)
255 {
256 struct chip_data *chip = drv_data->cur_chip;
257
258 if (drv_data->ssp_type == CE4100_SSP) {
259 pxa2xx_spi_write(drv_data, SSSR, drv_data->cur_chip->frm);
260 return;
261 }
262
263 if (chip->cs_control) {
264 chip->cs_control(PXA2XX_CS_ASSERT);
265 return;
266 }
267
268 if (gpio_is_valid(chip->gpio_cs)) {
269 gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
270 return;
271 }
272
273 if (is_lpss_ssp(drv_data))
274 lpss_ssp_cs_control(drv_data, true);
275 }
276
277 static void cs_deassert(struct driver_data *drv_data)
278 {
279 struct chip_data *chip = drv_data->cur_chip;
280
281 if (drv_data->ssp_type == CE4100_SSP)
282 return;
283
284 if (chip->cs_control) {
285 chip->cs_control(PXA2XX_CS_DEASSERT);
286 return;
287 }
288
289 if (gpio_is_valid(chip->gpio_cs)) {
290 gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
291 return;
292 }
293
294 if (is_lpss_ssp(drv_data))
295 lpss_ssp_cs_control(drv_data, false);
296 }
297
298 int pxa2xx_spi_flush(struct driver_data *drv_data)
299 {
300 unsigned long limit = loops_per_jiffy << 1;
301
302 do {
303 while (pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
304 pxa2xx_spi_read(drv_data, SSDR);
305 } while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY) && --limit);
306 write_SSSR_CS(drv_data, SSSR_ROR);
307
308 return limit;
309 }
310
311 static int null_writer(struct driver_data *drv_data)
312 {
313 u8 n_bytes = drv_data->n_bytes;
314
315 if (pxa2xx_spi_txfifo_full(drv_data)
316 || (drv_data->tx == drv_data->tx_end))
317 return 0;
318
319 pxa2xx_spi_write(drv_data, SSDR, 0);
320 drv_data->tx += n_bytes;
321
322 return 1;
323 }
324
325 static int null_reader(struct driver_data *drv_data)
326 {
327 u8 n_bytes = drv_data->n_bytes;
328
329 while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
330 && (drv_data->rx < drv_data->rx_end)) {
331 pxa2xx_spi_read(drv_data, SSDR);
332 drv_data->rx += n_bytes;
333 }
334
335 return drv_data->rx == drv_data->rx_end;
336 }
337
338 static int u8_writer(struct driver_data *drv_data)
339 {
340 if (pxa2xx_spi_txfifo_full(drv_data)
341 || (drv_data->tx == drv_data->tx_end))
342 return 0;
343
344 pxa2xx_spi_write(drv_data, SSDR, *(u8 *)(drv_data->tx));
345 ++drv_data->tx;
346
347 return 1;
348 }
349
350 static int u8_reader(struct driver_data *drv_data)
351 {
352 while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
353 && (drv_data->rx < drv_data->rx_end)) {
354 *(u8 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
355 ++drv_data->rx;
356 }
357
358 return drv_data->rx == drv_data->rx_end;
359 }
360
361 static int u16_writer(struct driver_data *drv_data)
362 {
363 if (pxa2xx_spi_txfifo_full(drv_data)
364 || (drv_data->tx == drv_data->tx_end))
365 return 0;
366
367 pxa2xx_spi_write(drv_data, SSDR, *(u16 *)(drv_data->tx));
368 drv_data->tx += 2;
369
370 return 1;
371 }
372
373 static int u16_reader(struct driver_data *drv_data)
374 {
375 while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
376 && (drv_data->rx < drv_data->rx_end)) {
377 *(u16 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
378 drv_data->rx += 2;
379 }
380
381 return drv_data->rx == drv_data->rx_end;
382 }
383
384 static int u32_writer(struct driver_data *drv_data)
385 {
386 if (pxa2xx_spi_txfifo_full(drv_data)
387 || (drv_data->tx == drv_data->tx_end))
388 return 0;
389
390 pxa2xx_spi_write(drv_data, SSDR, *(u32 *)(drv_data->tx));
391 drv_data->tx += 4;
392
393 return 1;
394 }
395
396 static int u32_reader(struct driver_data *drv_data)
397 {
398 while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
399 && (drv_data->rx < drv_data->rx_end)) {
400 *(u32 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
401 drv_data->rx += 4;
402 }
403
404 return drv_data->rx == drv_data->rx_end;
405 }
406
407 void *pxa2xx_spi_next_transfer(struct driver_data *drv_data)
408 {
409 struct spi_message *msg = drv_data->cur_msg;
410 struct spi_transfer *trans = drv_data->cur_transfer;
411
412 /* Move to next transfer */
413 if (trans->transfer_list.next != &msg->transfers) {
414 drv_data->cur_transfer =
415 list_entry(trans->transfer_list.next,
416 struct spi_transfer,
417 transfer_list);
418 return RUNNING_STATE;
419 } else
420 return DONE_STATE;
421 }
422
423 /* caller already set message->status; dma and pio irqs are blocked */
424 static void giveback(struct driver_data *drv_data)
425 {
426 struct spi_transfer* last_transfer;
427 struct spi_message *msg;
428
429 msg = drv_data->cur_msg;
430 drv_data->cur_msg = NULL;
431 drv_data->cur_transfer = NULL;
432
433 last_transfer = list_last_entry(&msg->transfers, struct spi_transfer,
434 transfer_list);
435
436 /* Delay if requested before any change in chip select */
437 if (last_transfer->delay_usecs)
438 udelay(last_transfer->delay_usecs);
439
440 /* Drop chip select UNLESS cs_change is true or we are returning
441 * a message with an error, or next message is for another chip
442 */
443 if (!last_transfer->cs_change)
444 cs_deassert(drv_data);
445 else {
446 struct spi_message *next_msg;
447
448 /* Holding of cs was hinted, but we need to make sure
449 * the next message is for the same chip. Don't waste
450 * time with the following tests unless this was hinted.
451 *
452 * We cannot postpone this until pump_messages, because
453 * after calling msg->complete (below) the driver that
454 * sent the current message could be unloaded, which
455 * could invalidate the cs_control() callback...
456 */
457
458 /* get a pointer to the next message, if any */
459 next_msg = spi_get_next_queued_message(drv_data->master);
460
461 /* see if the next and current messages point
462 * to the same chip
463 */
464 if (next_msg && next_msg->spi != msg->spi)
465 next_msg = NULL;
466 if (!next_msg || msg->state == ERROR_STATE)
467 cs_deassert(drv_data);
468 }
469
470 drv_data->cur_chip = NULL;
471 spi_finalize_current_message(drv_data->master);
472 }
473
474 static void reset_sccr1(struct driver_data *drv_data)
475 {
476 struct chip_data *chip = drv_data->cur_chip;
477 u32 sccr1_reg;
478
479 sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1) & ~drv_data->int_cr1;
480 sccr1_reg &= ~SSCR1_RFT;
481 sccr1_reg |= chip->threshold;
482 pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg);
483 }
484
485 static void int_error_stop(struct driver_data *drv_data, const char* msg)
486 {
487 /* Stop and reset SSP */
488 write_SSSR_CS(drv_data, drv_data->clear_sr);
489 reset_sccr1(drv_data);
490 if (!pxa25x_ssp_comp(drv_data))
491 pxa2xx_spi_write(drv_data, SSTO, 0);
492 pxa2xx_spi_flush(drv_data);
493 pxa2xx_spi_write(drv_data, SSCR0,
494 pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
495
496 dev_err(&drv_data->pdev->dev, "%s\n", msg);
497
498 drv_data->cur_msg->state = ERROR_STATE;
499 tasklet_schedule(&drv_data->pump_transfers);
500 }
501
502 static void int_transfer_complete(struct driver_data *drv_data)
503 {
504 /* Stop SSP */
505 write_SSSR_CS(drv_data, drv_data->clear_sr);
506 reset_sccr1(drv_data);
507 if (!pxa25x_ssp_comp(drv_data))
508 pxa2xx_spi_write(drv_data, SSTO, 0);
509
510 /* Update total byte transferred return count actual bytes read */
511 drv_data->cur_msg->actual_length += drv_data->len -
512 (drv_data->rx_end - drv_data->rx);
513
514 /* Transfer delays and chip select release are
515 * handled in pump_transfers or giveback
516 */
517
518 /* Move to next transfer */
519 drv_data->cur_msg->state = pxa2xx_spi_next_transfer(drv_data);
520
521 /* Schedule transfer tasklet */
522 tasklet_schedule(&drv_data->pump_transfers);
523 }
524
525 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
526 {
527 u32 irq_mask = (pxa2xx_spi_read(drv_data, SSCR1) & SSCR1_TIE) ?
528 drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
529
530 u32 irq_status = pxa2xx_spi_read(drv_data, SSSR) & irq_mask;
531
532 if (irq_status & SSSR_ROR) {
533 int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
534 return IRQ_HANDLED;
535 }
536
537 if (irq_status & SSSR_TINT) {
538 pxa2xx_spi_write(drv_data, SSSR, SSSR_TINT);
539 if (drv_data->read(drv_data)) {
540 int_transfer_complete(drv_data);
541 return IRQ_HANDLED;
542 }
543 }
544
545 /* Drain rx fifo, Fill tx fifo and prevent overruns */
546 do {
547 if (drv_data->read(drv_data)) {
548 int_transfer_complete(drv_data);
549 return IRQ_HANDLED;
550 }
551 } while (drv_data->write(drv_data));
552
553 if (drv_data->read(drv_data)) {
554 int_transfer_complete(drv_data);
555 return IRQ_HANDLED;
556 }
557
558 if (drv_data->tx == drv_data->tx_end) {
559 u32 bytes_left;
560 u32 sccr1_reg;
561
562 sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1);
563 sccr1_reg &= ~SSCR1_TIE;
564
565 /*
566 * PXA25x_SSP has no timeout, set up rx threshould for the
567 * remaining RX bytes.
568 */
569 if (pxa25x_ssp_comp(drv_data)) {
570 u32 rx_thre;
571
572 pxa2xx_spi_clear_rx_thre(drv_data, &sccr1_reg);
573
574 bytes_left = drv_data->rx_end - drv_data->rx;
575 switch (drv_data->n_bytes) {
576 case 4:
577 bytes_left >>= 1;
578 case 2:
579 bytes_left >>= 1;
580 }
581
582 rx_thre = pxa2xx_spi_get_rx_default_thre(drv_data);
583 if (rx_thre > bytes_left)
584 rx_thre = bytes_left;
585
586 pxa2xx_spi_set_rx_thre(drv_data, &sccr1_reg, rx_thre);
587 }
588 pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg);
589 }
590
591 /* We did something */
592 return IRQ_HANDLED;
593 }
594
595 static irqreturn_t ssp_int(int irq, void *dev_id)
596 {
597 struct driver_data *drv_data = dev_id;
598 u32 sccr1_reg;
599 u32 mask = drv_data->mask_sr;
600 u32 status;
601
602 /*
603 * The IRQ might be shared with other peripherals so we must first
604 * check that are we RPM suspended or not. If we are we assume that
605 * the IRQ was not for us (we shouldn't be RPM suspended when the
606 * interrupt is enabled).
607 */
608 if (pm_runtime_suspended(&drv_data->pdev->dev))
609 return IRQ_NONE;
610
611 /*
612 * If the device is not yet in RPM suspended state and we get an
613 * interrupt that is meant for another device, check if status bits
614 * are all set to one. That means that the device is already
615 * powered off.
616 */
617 status = pxa2xx_spi_read(drv_data, SSSR);
618 if (status == ~0)
619 return IRQ_NONE;
620
621 sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1);
622
623 /* Ignore possible writes if we don't need to write */
624 if (!(sccr1_reg & SSCR1_TIE))
625 mask &= ~SSSR_TFS;
626
627 if (!(status & mask))
628 return IRQ_NONE;
629
630 if (!drv_data->cur_msg) {
631
632 pxa2xx_spi_write(drv_data, SSCR0,
633 pxa2xx_spi_read(drv_data, SSCR0)
634 & ~SSCR0_SSE);
635 pxa2xx_spi_write(drv_data, SSCR1,
636 pxa2xx_spi_read(drv_data, SSCR1)
637 & ~drv_data->int_cr1);
638 if (!pxa25x_ssp_comp(drv_data))
639 pxa2xx_spi_write(drv_data, SSTO, 0);
640 write_SSSR_CS(drv_data, drv_data->clear_sr);
641
642 dev_err(&drv_data->pdev->dev,
643 "bad message state in interrupt handler\n");
644
645 /* Never fail */
646 return IRQ_HANDLED;
647 }
648
649 return drv_data->transfer_handler(drv_data);
650 }
651
652 /*
653 * The Quark SPI has an additional 24 bit register (DDS_CLK_RATE) to multiply
654 * input frequency by fractions of 2^24. It also has a divider by 5.
655 *
656 * There are formulas to get baud rate value for given input frequency and
657 * divider parameters, such as DDS_CLK_RATE and SCR:
658 *
659 * Fsys = 200MHz
660 *
661 * Fssp = Fsys * DDS_CLK_RATE / 2^24 (1)
662 * Baud rate = Fsclk = Fssp / (2 * (SCR + 1)) (2)
663 *
664 * DDS_CLK_RATE either 2^n or 2^n / 5.
665 * SCR is in range 0 .. 255
666 *
667 * Divisor = 5^i * 2^j * 2 * k
668 * i = [0, 1] i = 1 iff j = 0 or j > 3
669 * j = [0, 23] j = 0 iff i = 1
670 * k = [1, 256]
671 * Special case: j = 0, i = 1: Divisor = 2 / 5
672 *
673 * Accordingly to the specification the recommended values for DDS_CLK_RATE
674 * are:
675 * Case 1: 2^n, n = [0, 23]
676 * Case 2: 2^24 * 2 / 5 (0x666666)
677 * Case 3: less than or equal to 2^24 / 5 / 16 (0x33333)
678 *
679 * In all cases the lowest possible value is better.
680 *
681 * The function calculates parameters for all cases and chooses the one closest
682 * to the asked baud rate.
683 */
684 static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds)
685 {
686 unsigned long xtal = 200000000;
687 unsigned long fref = xtal / 2; /* mandatory division by 2,
688 see (2) */
689 /* case 3 */
690 unsigned long fref1 = fref / 2; /* case 1 */
691 unsigned long fref2 = fref * 2 / 5; /* case 2 */
692 unsigned long scale;
693 unsigned long q, q1, q2;
694 long r, r1, r2;
695 u32 mul;
696
697 /* Case 1 */
698
699 /* Set initial value for DDS_CLK_RATE */
700 mul = (1 << 24) >> 1;
701
702 /* Calculate initial quot */
703 q1 = DIV_ROUND_CLOSEST(fref1, rate);
704
705 /* Scale q1 if it's too big */
706 if (q1 > 256) {
707 /* Scale q1 to range [1, 512] */
708 scale = fls_long(q1 - 1);
709 if (scale > 9) {
710 q1 >>= scale - 9;
711 mul >>= scale - 9;
712 }
713
714 /* Round the result if we have a remainder */
715 q1 += q1 & 1;
716 }
717
718 /* Decrease DDS_CLK_RATE as much as we can without loss in precision */
719 scale = __ffs(q1);
720 q1 >>= scale;
721 mul >>= scale;
722
723 /* Get the remainder */
724 r1 = abs(fref1 / (1 << (24 - fls_long(mul))) / q1 - rate);
725
726 /* Case 2 */
727
728 q2 = DIV_ROUND_CLOSEST(fref2, rate);
729 r2 = abs(fref2 / q2 - rate);
730
731 /*
732 * Choose the best between two: less remainder we have the better. We
733 * can't go case 2 if q2 is greater than 256 since SCR register can
734 * hold only values 0 .. 255.
735 */
736 if (r2 >= r1 || q2 > 256) {
737 /* case 1 is better */
738 r = r1;
739 q = q1;
740 } else {
741 /* case 2 is better */
742 r = r2;
743 q = q2;
744 mul = (1 << 24) * 2 / 5;
745 }
746
747 /* Check case 3 only If the divisor is big enough */
748 if (fref / rate >= 80) {
749 u64 fssp;
750 u32 m;
751
752 /* Calculate initial quot */
753 q1 = DIV_ROUND_CLOSEST(fref, rate);
754 m = (1 << 24) / q1;
755
756 /* Get the remainder */
757 fssp = (u64)fref * m;
758 do_div(fssp, 1 << 24);
759 r1 = abs(fssp - rate);
760
761 /* Choose this one if it suits better */
762 if (r1 < r) {
763 /* case 3 is better */
764 q = 1;
765 mul = m;
766 }
767 }
768
769 *dds = mul;
770 return q - 1;
771 }
772
773 static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
774 {
775 unsigned long ssp_clk = drv_data->max_clk_rate;
776 const struct ssp_device *ssp = drv_data->ssp;
777
778 rate = min_t(int, ssp_clk, rate);
779
780 if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP)
781 return (ssp_clk / (2 * rate) - 1) & 0xff;
782 else
783 return (ssp_clk / rate - 1) & 0xfff;
784 }
785
786 static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data,
787 struct chip_data *chip, int rate)
788 {
789 unsigned int clk_div;
790
791 switch (drv_data->ssp_type) {
792 case QUARK_X1000_SSP:
793 clk_div = quark_x1000_get_clk_div(rate, &chip->dds_rate);
794 break;
795 default:
796 clk_div = ssp_get_clk_div(drv_data, rate);
797 break;
798 }
799 return clk_div << 8;
800 }
801
802 static void pump_transfers(unsigned long data)
803 {
804 struct driver_data *drv_data = (struct driver_data *)data;
805 struct spi_message *message = NULL;
806 struct spi_transfer *transfer = NULL;
807 struct spi_transfer *previous = NULL;
808 struct chip_data *chip = NULL;
809 u32 clk_div = 0;
810 u8 bits = 0;
811 u32 speed = 0;
812 u32 cr0;
813 u32 cr1;
814 u32 dma_thresh = drv_data->cur_chip->dma_threshold;
815 u32 dma_burst = drv_data->cur_chip->dma_burst_size;
816 u32 change_mask = pxa2xx_spi_get_ssrc1_change_mask(drv_data);
817
818 /* Get current state information */
819 message = drv_data->cur_msg;
820 transfer = drv_data->cur_transfer;
821 chip = drv_data->cur_chip;
822
823 /* Handle for abort */
824 if (message->state == ERROR_STATE) {
825 message->status = -EIO;
826 giveback(drv_data);
827 return;
828 }
829
830 /* Handle end of message */
831 if (message->state == DONE_STATE) {
832 message->status = 0;
833 giveback(drv_data);
834 return;
835 }
836
837 /* Delay if requested at end of transfer before CS change */
838 if (message->state == RUNNING_STATE) {
839 previous = list_entry(transfer->transfer_list.prev,
840 struct spi_transfer,
841 transfer_list);
842 if (previous->delay_usecs)
843 udelay(previous->delay_usecs);
844
845 /* Drop chip select only if cs_change is requested */
846 if (previous->cs_change)
847 cs_deassert(drv_data);
848 }
849
850 /* Check if we can DMA this transfer */
851 if (!pxa2xx_spi_dma_is_possible(transfer->len) && chip->enable_dma) {
852
853 /* reject already-mapped transfers; PIO won't always work */
854 if (message->is_dma_mapped
855 || transfer->rx_dma || transfer->tx_dma) {
856 dev_err(&drv_data->pdev->dev,
857 "pump_transfers: mapped transfer length of "
858 "%u is greater than %d\n",
859 transfer->len, MAX_DMA_LEN);
860 message->status = -EINVAL;
861 giveback(drv_data);
862 return;
863 }
864
865 /* warn ... we force this to PIO mode */
866 dev_warn_ratelimited(&message->spi->dev,
867 "pump_transfers: DMA disabled for transfer length %ld "
868 "greater than %d\n",
869 (long)drv_data->len, MAX_DMA_LEN);
870 }
871
872 /* Setup the transfer state based on the type of transfer */
873 if (pxa2xx_spi_flush(drv_data) == 0) {
874 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
875 message->status = -EIO;
876 giveback(drv_data);
877 return;
878 }
879 drv_data->n_bytes = chip->n_bytes;
880 drv_data->tx = (void *)transfer->tx_buf;
881 drv_data->tx_end = drv_data->tx + transfer->len;
882 drv_data->rx = transfer->rx_buf;
883 drv_data->rx_end = drv_data->rx + transfer->len;
884 drv_data->rx_dma = transfer->rx_dma;
885 drv_data->tx_dma = transfer->tx_dma;
886 drv_data->len = transfer->len;
887 drv_data->write = drv_data->tx ? chip->write : null_writer;
888 drv_data->read = drv_data->rx ? chip->read : null_reader;
889
890 /* Change speed and bit per word on a per transfer */
891 cr0 = chip->cr0;
892 if (transfer->speed_hz || transfer->bits_per_word) {
893
894 bits = chip->bits_per_word;
895 speed = chip->speed_hz;
896
897 if (transfer->speed_hz)
898 speed = transfer->speed_hz;
899
900 if (transfer->bits_per_word)
901 bits = transfer->bits_per_word;
902
903 clk_div = pxa2xx_ssp_get_clk_div(drv_data, chip, speed);
904
905 if (bits <= 8) {
906 drv_data->n_bytes = 1;
907 drv_data->read = drv_data->read != null_reader ?
908 u8_reader : null_reader;
909 drv_data->write = drv_data->write != null_writer ?
910 u8_writer : null_writer;
911 } else if (bits <= 16) {
912 drv_data->n_bytes = 2;
913 drv_data->read = drv_data->read != null_reader ?
914 u16_reader : null_reader;
915 drv_data->write = drv_data->write != null_writer ?
916 u16_writer : null_writer;
917 } else if (bits <= 32) {
918 drv_data->n_bytes = 4;
919 drv_data->read = drv_data->read != null_reader ?
920 u32_reader : null_reader;
921 drv_data->write = drv_data->write != null_writer ?
922 u32_writer : null_writer;
923 }
924 /* if bits/word is changed in dma mode, then must check the
925 * thresholds and burst also */
926 if (chip->enable_dma) {
927 if (pxa2xx_spi_set_dma_burst_and_threshold(chip,
928 message->spi,
929 bits, &dma_burst,
930 &dma_thresh))
931 dev_warn_ratelimited(&message->spi->dev,
932 "pump_transfers: DMA burst size reduced to match bits_per_word\n");
933 }
934
935 cr0 = pxa2xx_configure_sscr0(drv_data, clk_div, bits);
936 }
937
938 message->state = RUNNING_STATE;
939
940 drv_data->dma_mapped = 0;
941 if (pxa2xx_spi_dma_is_possible(drv_data->len))
942 drv_data->dma_mapped = pxa2xx_spi_map_dma_buffers(drv_data);
943 if (drv_data->dma_mapped) {
944
945 /* Ensure we have the correct interrupt handler */
946 drv_data->transfer_handler = pxa2xx_spi_dma_transfer;
947
948 pxa2xx_spi_dma_prepare(drv_data, dma_burst);
949
950 /* Clear status and start DMA engine */
951 cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
952 pxa2xx_spi_write(drv_data, SSSR, drv_data->clear_sr);
953
954 pxa2xx_spi_dma_start(drv_data);
955 } else {
956 /* Ensure we have the correct interrupt handler */
957 drv_data->transfer_handler = interrupt_transfer;
958
959 /* Clear status */
960 cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
961 write_SSSR_CS(drv_data, drv_data->clear_sr);
962 }
963
964 if (is_lpss_ssp(drv_data)) {
965 if ((pxa2xx_spi_read(drv_data, SSIRF) & 0xff)
966 != chip->lpss_rx_threshold)
967 pxa2xx_spi_write(drv_data, SSIRF,
968 chip->lpss_rx_threshold);
969 if ((pxa2xx_spi_read(drv_data, SSITF) & 0xffff)
970 != chip->lpss_tx_threshold)
971 pxa2xx_spi_write(drv_data, SSITF,
972 chip->lpss_tx_threshold);
973 }
974
975 if (is_quark_x1000_ssp(drv_data) &&
976 (pxa2xx_spi_read(drv_data, DDS_RATE) != chip->dds_rate))
977 pxa2xx_spi_write(drv_data, DDS_RATE, chip->dds_rate);
978
979 /* see if we need to reload the config registers */
980 if ((pxa2xx_spi_read(drv_data, SSCR0) != cr0)
981 || (pxa2xx_spi_read(drv_data, SSCR1) & change_mask)
982 != (cr1 & change_mask)) {
983 /* stop the SSP, and update the other bits */
984 pxa2xx_spi_write(drv_data, SSCR0, cr0 & ~SSCR0_SSE);
985 if (!pxa25x_ssp_comp(drv_data))
986 pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
987 /* first set CR1 without interrupt and service enables */
988 pxa2xx_spi_write(drv_data, SSCR1, cr1 & change_mask);
989 /* restart the SSP */
990 pxa2xx_spi_write(drv_data, SSCR0, cr0);
991
992 } else {
993 if (!pxa25x_ssp_comp(drv_data))
994 pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
995 }
996
997 cs_assert(drv_data);
998
999 /* after chip select, release the data by enabling service
1000 * requests and interrupts, without changing any mode bits */
1001 pxa2xx_spi_write(drv_data, SSCR1, cr1);
1002 }
1003
1004 static int pxa2xx_spi_transfer_one_message(struct spi_master *master,
1005 struct spi_message *msg)
1006 {
1007 struct driver_data *drv_data = spi_master_get_devdata(master);
1008
1009 drv_data->cur_msg = msg;
1010 /* Initial message state*/
1011 drv_data->cur_msg->state = START_STATE;
1012 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1013 struct spi_transfer,
1014 transfer_list);
1015
1016 /* prepare to setup the SSP, in pump_transfers, using the per
1017 * chip configuration */
1018 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1019
1020 /* Mark as busy and launch transfers */
1021 tasklet_schedule(&drv_data->pump_transfers);
1022 return 0;
1023 }
1024
1025 static int pxa2xx_spi_unprepare_transfer(struct spi_master *master)
1026 {
1027 struct driver_data *drv_data = spi_master_get_devdata(master);
1028
1029 /* Disable the SSP now */
1030 pxa2xx_spi_write(drv_data, SSCR0,
1031 pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
1032
1033 return 0;
1034 }
1035
1036 static int setup_cs(struct spi_device *spi, struct chip_data *chip,
1037 struct pxa2xx_spi_chip *chip_info)
1038 {
1039 int err = 0;
1040
1041 if (chip == NULL || chip_info == NULL)
1042 return 0;
1043
1044 /* NOTE: setup() can be called multiple times, possibly with
1045 * different chip_info, release previously requested GPIO
1046 */
1047 if (gpio_is_valid(chip->gpio_cs))
1048 gpio_free(chip->gpio_cs);
1049
1050 /* If (*cs_control) is provided, ignore GPIO chip select */
1051 if (chip_info->cs_control) {
1052 chip->cs_control = chip_info->cs_control;
1053 return 0;
1054 }
1055
1056 if (gpio_is_valid(chip_info->gpio_cs)) {
1057 err = gpio_request(chip_info->gpio_cs, "SPI_CS");
1058 if (err) {
1059 dev_err(&spi->dev, "failed to request chip select GPIO%d\n",
1060 chip_info->gpio_cs);
1061 return err;
1062 }
1063
1064 chip->gpio_cs = chip_info->gpio_cs;
1065 chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
1066
1067 err = gpio_direction_output(chip->gpio_cs,
1068 !chip->gpio_cs_inverted);
1069 }
1070
1071 return err;
1072 }
1073
1074 static int setup(struct spi_device *spi)
1075 {
1076 struct pxa2xx_spi_chip *chip_info = NULL;
1077 struct chip_data *chip;
1078 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1079 unsigned int clk_div;
1080 uint tx_thres, tx_hi_thres, rx_thres;
1081
1082 switch (drv_data->ssp_type) {
1083 case QUARK_X1000_SSP:
1084 tx_thres = TX_THRESH_QUARK_X1000_DFLT;
1085 tx_hi_thres = 0;
1086 rx_thres = RX_THRESH_QUARK_X1000_DFLT;
1087 break;
1088 case LPSS_SSP:
1089 tx_thres = LPSS_TX_LOTHRESH_DFLT;
1090 tx_hi_thres = LPSS_TX_HITHRESH_DFLT;
1091 rx_thres = LPSS_RX_THRESH_DFLT;
1092 break;
1093 default:
1094 tx_thres = TX_THRESH_DFLT;
1095 tx_hi_thres = 0;
1096 rx_thres = RX_THRESH_DFLT;
1097 break;
1098 }
1099
1100 /* Only alloc on first setup */
1101 chip = spi_get_ctldata(spi);
1102 if (!chip) {
1103 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1104 if (!chip)
1105 return -ENOMEM;
1106
1107 if (drv_data->ssp_type == CE4100_SSP) {
1108 if (spi->chip_select > 4) {
1109 dev_err(&spi->dev,
1110 "failed setup: cs number must not be > 4.\n");
1111 kfree(chip);
1112 return -EINVAL;
1113 }
1114
1115 chip->frm = spi->chip_select;
1116 } else
1117 chip->gpio_cs = -1;
1118 chip->enable_dma = 0;
1119 chip->timeout = TIMOUT_DFLT;
1120 }
1121
1122 /* protocol drivers may change the chip settings, so...
1123 * if chip_info exists, use it */
1124 chip_info = spi->controller_data;
1125
1126 /* chip_info isn't always needed */
1127 chip->cr1 = 0;
1128 if (chip_info) {
1129 if (chip_info->timeout)
1130 chip->timeout = chip_info->timeout;
1131 if (chip_info->tx_threshold)
1132 tx_thres = chip_info->tx_threshold;
1133 if (chip_info->tx_hi_threshold)
1134 tx_hi_thres = chip_info->tx_hi_threshold;
1135 if (chip_info->rx_threshold)
1136 rx_thres = chip_info->rx_threshold;
1137 chip->enable_dma = drv_data->master_info->enable_dma;
1138 chip->dma_threshold = 0;
1139 if (chip_info->enable_loopback)
1140 chip->cr1 = SSCR1_LBM;
1141 } else if (ACPI_HANDLE(&spi->dev)) {
1142 /*
1143 * Slave devices enumerated from ACPI namespace don't
1144 * usually have chip_info but we still might want to use
1145 * DMA with them.
1146 */
1147 chip->enable_dma = drv_data->master_info->enable_dma;
1148 }
1149
1150 chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);
1151 chip->lpss_tx_threshold = SSITF_TxLoThresh(tx_thres)
1152 | SSITF_TxHiThresh(tx_hi_thres);
1153
1154 /* set dma burst and threshold outside of chip_info path so that if
1155 * chip_info goes away after setting chip->enable_dma, the
1156 * burst and threshold can still respond to changes in bits_per_word */
1157 if (chip->enable_dma) {
1158 /* set up legal burst and threshold for dma */
1159 if (pxa2xx_spi_set_dma_burst_and_threshold(chip, spi,
1160 spi->bits_per_word,
1161 &chip->dma_burst_size,
1162 &chip->dma_threshold)) {
1163 dev_warn(&spi->dev,
1164 "in setup: DMA burst size reduced to match bits_per_word\n");
1165 }
1166 }
1167
1168 clk_div = pxa2xx_ssp_get_clk_div(drv_data, chip, spi->max_speed_hz);
1169 chip->speed_hz = spi->max_speed_hz;
1170
1171 chip->cr0 = pxa2xx_configure_sscr0(drv_data, clk_div,
1172 spi->bits_per_word);
1173 switch (drv_data->ssp_type) {
1174 case QUARK_X1000_SSP:
1175 chip->threshold = (QUARK_X1000_SSCR1_RxTresh(rx_thres)
1176 & QUARK_X1000_SSCR1_RFT)
1177 | (QUARK_X1000_SSCR1_TxTresh(tx_thres)
1178 & QUARK_X1000_SSCR1_TFT);
1179 break;
1180 default:
1181 chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
1182 (SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
1183 break;
1184 }
1185
1186 chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
1187 chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
1188 | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
1189
1190 if (spi->mode & SPI_LOOP)
1191 chip->cr1 |= SSCR1_LBM;
1192
1193 /* NOTE: PXA25x_SSP _could_ use external clocking ... */
1194 if (!pxa25x_ssp_comp(drv_data))
1195 dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
1196 drv_data->max_clk_rate
1197 / (1 + ((chip->cr0 & SSCR0_SCR(0xfff)) >> 8)),
1198 chip->enable_dma ? "DMA" : "PIO");
1199 else
1200 dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
1201 drv_data->max_clk_rate / 2
1202 / (1 + ((chip->cr0 & SSCR0_SCR(0x0ff)) >> 8)),
1203 chip->enable_dma ? "DMA" : "PIO");
1204
1205 if (spi->bits_per_word <= 8) {
1206 chip->n_bytes = 1;
1207 chip->read = u8_reader;
1208 chip->write = u8_writer;
1209 } else if (spi->bits_per_word <= 16) {
1210 chip->n_bytes = 2;
1211 chip->read = u16_reader;
1212 chip->write = u16_writer;
1213 } else if (spi->bits_per_word <= 32) {
1214 if (!is_quark_x1000_ssp(drv_data))
1215 chip->cr0 |= SSCR0_EDSS;
1216 chip->n_bytes = 4;
1217 chip->read = u32_reader;
1218 chip->write = u32_writer;
1219 }
1220 chip->bits_per_word = spi->bits_per_word;
1221
1222 spi_set_ctldata(spi, chip);
1223
1224 if (drv_data->ssp_type == CE4100_SSP)
1225 return 0;
1226
1227 return setup_cs(spi, chip, chip_info);
1228 }
1229
1230 static void cleanup(struct spi_device *spi)
1231 {
1232 struct chip_data *chip = spi_get_ctldata(spi);
1233 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1234
1235 if (!chip)
1236 return;
1237
1238 if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
1239 gpio_free(chip->gpio_cs);
1240
1241 kfree(chip);
1242 }
1243
1244 #ifdef CONFIG_ACPI
1245 static struct pxa2xx_spi_master *
1246 pxa2xx_spi_acpi_get_pdata(struct platform_device *pdev)
1247 {
1248 struct pxa2xx_spi_master *pdata;
1249 struct acpi_device *adev;
1250 struct ssp_device *ssp;
1251 struct resource *res;
1252 int devid;
1253
1254 if (!ACPI_HANDLE(&pdev->dev) ||
1255 acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
1256 return NULL;
1257
1258 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1259 if (!pdata)
1260 return NULL;
1261
1262 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1263 if (!res)
1264 return NULL;
1265
1266 ssp = &pdata->ssp;
1267
1268 ssp->phys_base = res->start;
1269 ssp->mmio_base = devm_ioremap_resource(&pdev->dev, res);
1270 if (IS_ERR(ssp->mmio_base))
1271 return NULL;
1272
1273 ssp->clk = devm_clk_get(&pdev->dev, NULL);
1274 ssp->irq = platform_get_irq(pdev, 0);
1275 ssp->type = LPSS_SSP;
1276 ssp->pdev = pdev;
1277
1278 ssp->port_id = -1;
1279 if (adev->pnp.unique_id && !kstrtoint(adev->pnp.unique_id, 0, &devid))
1280 ssp->port_id = devid;
1281
1282 pdata->num_chipselect = 1;
1283 pdata->enable_dma = true;
1284
1285 return pdata;
1286 }
1287
1288 static struct acpi_device_id pxa2xx_spi_acpi_match[] = {
1289 { "INT33C0", 0 },
1290 { "INT33C1", 0 },
1291 { "INT3430", 0 },
1292 { "INT3431", 0 },
1293 { "80860F0E", 0 },
1294 { "8086228E", 0 },
1295 { },
1296 };
1297 MODULE_DEVICE_TABLE(acpi, pxa2xx_spi_acpi_match);
1298 #else
1299 static inline struct pxa2xx_spi_master *
1300 pxa2xx_spi_acpi_get_pdata(struct platform_device *pdev)
1301 {
1302 return NULL;
1303 }
1304 #endif
1305
1306 static int pxa2xx_spi_probe(struct platform_device *pdev)
1307 {
1308 struct device *dev = &pdev->dev;
1309 struct pxa2xx_spi_master *platform_info;
1310 struct spi_master *master;
1311 struct driver_data *drv_data;
1312 struct ssp_device *ssp;
1313 int status;
1314 u32 tmp;
1315
1316 platform_info = dev_get_platdata(dev);
1317 if (!platform_info) {
1318 platform_info = pxa2xx_spi_acpi_get_pdata(pdev);
1319 if (!platform_info) {
1320 dev_err(&pdev->dev, "missing platform data\n");
1321 return -ENODEV;
1322 }
1323 }
1324
1325 ssp = pxa_ssp_request(pdev->id, pdev->name);
1326 if (!ssp)
1327 ssp = &platform_info->ssp;
1328
1329 if (!ssp->mmio_base) {
1330 dev_err(&pdev->dev, "failed to get ssp\n");
1331 return -ENODEV;
1332 }
1333
1334 /* Allocate master with space for drv_data and null dma buffer */
1335 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1336 if (!master) {
1337 dev_err(&pdev->dev, "cannot alloc spi_master\n");
1338 pxa_ssp_free(ssp);
1339 return -ENOMEM;
1340 }
1341 drv_data = spi_master_get_devdata(master);
1342 drv_data->master = master;
1343 drv_data->master_info = platform_info;
1344 drv_data->pdev = pdev;
1345 drv_data->ssp = ssp;
1346
1347 master->dev.parent = &pdev->dev;
1348 master->dev.of_node = pdev->dev.of_node;
1349 /* the spi->mode bits understood by this driver: */
1350 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
1351
1352 master->bus_num = ssp->port_id;
1353 master->num_chipselect = platform_info->num_chipselect;
1354 master->dma_alignment = DMA_ALIGNMENT;
1355 master->cleanup = cleanup;
1356 master->setup = setup;
1357 master->transfer_one_message = pxa2xx_spi_transfer_one_message;
1358 master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer;
1359 master->auto_runtime_pm = true;
1360
1361 drv_data->ssp_type = ssp->type;
1362 drv_data->null_dma_buf = (u32 *)PTR_ALIGN(&drv_data[1], DMA_ALIGNMENT);
1363
1364 drv_data->ioaddr = ssp->mmio_base;
1365 drv_data->ssdr_physical = ssp->phys_base + SSDR;
1366 if (pxa25x_ssp_comp(drv_data)) {
1367 switch (drv_data->ssp_type) {
1368 case QUARK_X1000_SSP:
1369 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1370 break;
1371 default:
1372 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
1373 break;
1374 }
1375
1376 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
1377 drv_data->dma_cr1 = 0;
1378 drv_data->clear_sr = SSSR_ROR;
1379 drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
1380 } else {
1381 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1382 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
1383 drv_data->dma_cr1 = DEFAULT_DMA_CR1;
1384 drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
1385 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
1386 }
1387
1388 status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev),
1389 drv_data);
1390 if (status < 0) {
1391 dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
1392 goto out_error_master_alloc;
1393 }
1394
1395 /* Setup DMA if requested */
1396 drv_data->tx_channel = -1;
1397 drv_data->rx_channel = -1;
1398 if (platform_info->enable_dma) {
1399 status = pxa2xx_spi_dma_setup(drv_data);
1400 if (status) {
1401 dev_dbg(dev, "no DMA channels available, using PIO\n");
1402 platform_info->enable_dma = false;
1403 }
1404 }
1405
1406 /* Enable SOC clock */
1407 clk_prepare_enable(ssp->clk);
1408
1409 drv_data->max_clk_rate = clk_get_rate(ssp->clk);
1410
1411 /* Load default SSP configuration */
1412 pxa2xx_spi_write(drv_data, SSCR0, 0);
1413 switch (drv_data->ssp_type) {
1414 case QUARK_X1000_SSP:
1415 tmp = QUARK_X1000_SSCR1_RxTresh(RX_THRESH_QUARK_X1000_DFLT)
1416 | QUARK_X1000_SSCR1_TxTresh(TX_THRESH_QUARK_X1000_DFLT);
1417 pxa2xx_spi_write(drv_data, SSCR1, tmp);
1418
1419 /* using the Motorola SPI protocol and use 8 bit frame */
1420 pxa2xx_spi_write(drv_data, SSCR0,
1421 QUARK_X1000_SSCR0_Motorola
1422 | QUARK_X1000_SSCR0_DataSize(8));
1423 break;
1424 default:
1425 tmp = SSCR1_RxTresh(RX_THRESH_DFLT) |
1426 SSCR1_TxTresh(TX_THRESH_DFLT);
1427 pxa2xx_spi_write(drv_data, SSCR1, tmp);
1428 tmp = SSCR0_SCR(2) | SSCR0_Motorola | SSCR0_DataSize(8);
1429 pxa2xx_spi_write(drv_data, SSCR0, tmp);
1430 break;
1431 }
1432
1433 if (!pxa25x_ssp_comp(drv_data))
1434 pxa2xx_spi_write(drv_data, SSTO, 0);
1435
1436 if (!is_quark_x1000_ssp(drv_data))
1437 pxa2xx_spi_write(drv_data, SSPSP, 0);
1438
1439 if (is_lpss_ssp(drv_data))
1440 lpss_ssp_setup(drv_data);
1441
1442 tasklet_init(&drv_data->pump_transfers, pump_transfers,
1443 (unsigned long)drv_data);
1444
1445 pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
1446 pm_runtime_use_autosuspend(&pdev->dev);
1447 pm_runtime_set_active(&pdev->dev);
1448 pm_runtime_enable(&pdev->dev);
1449
1450 /* Register with the SPI framework */
1451 platform_set_drvdata(pdev, drv_data);
1452 status = devm_spi_register_master(&pdev->dev, master);
1453 if (status != 0) {
1454 dev_err(&pdev->dev, "problem registering spi master\n");
1455 goto out_error_clock_enabled;
1456 }
1457
1458 return status;
1459
1460 out_error_clock_enabled:
1461 clk_disable_unprepare(ssp->clk);
1462 pxa2xx_spi_dma_release(drv_data);
1463 free_irq(ssp->irq, drv_data);
1464
1465 out_error_master_alloc:
1466 spi_master_put(master);
1467 pxa_ssp_free(ssp);
1468 return status;
1469 }
1470
1471 static int pxa2xx_spi_remove(struct platform_device *pdev)
1472 {
1473 struct driver_data *drv_data = platform_get_drvdata(pdev);
1474 struct ssp_device *ssp;
1475
1476 if (!drv_data)
1477 return 0;
1478 ssp = drv_data->ssp;
1479
1480 pm_runtime_get_sync(&pdev->dev);
1481
1482 /* Disable the SSP at the peripheral and SOC level */
1483 pxa2xx_spi_write(drv_data, SSCR0, 0);
1484 clk_disable_unprepare(ssp->clk);
1485
1486 /* Release DMA */
1487 if (drv_data->master_info->enable_dma)
1488 pxa2xx_spi_dma_release(drv_data);
1489
1490 pm_runtime_put_noidle(&pdev->dev);
1491 pm_runtime_disable(&pdev->dev);
1492
1493 /* Release IRQ */
1494 free_irq(ssp->irq, drv_data);
1495
1496 /* Release SSP */
1497 pxa_ssp_free(ssp);
1498
1499 return 0;
1500 }
1501
1502 static void pxa2xx_spi_shutdown(struct platform_device *pdev)
1503 {
1504 int status = 0;
1505
1506 if ((status = pxa2xx_spi_remove(pdev)) != 0)
1507 dev_err(&pdev->dev, "shutdown failed with %d\n", status);
1508 }
1509
1510 #ifdef CONFIG_PM_SLEEP
1511 static int pxa2xx_spi_suspend(struct device *dev)
1512 {
1513 struct driver_data *drv_data = dev_get_drvdata(dev);
1514 struct ssp_device *ssp = drv_data->ssp;
1515 int status = 0;
1516
1517 status = spi_master_suspend(drv_data->master);
1518 if (status != 0)
1519 return status;
1520 pxa2xx_spi_write(drv_data, SSCR0, 0);
1521
1522 if (!pm_runtime_suspended(dev))
1523 clk_disable_unprepare(ssp->clk);
1524
1525 return 0;
1526 }
1527
1528 static int pxa2xx_spi_resume(struct device *dev)
1529 {
1530 struct driver_data *drv_data = dev_get_drvdata(dev);
1531 struct ssp_device *ssp = drv_data->ssp;
1532 int status = 0;
1533
1534 pxa2xx_spi_dma_resume(drv_data);
1535
1536 /* Enable the SSP clock */
1537 if (!pm_runtime_suspended(dev))
1538 clk_prepare_enable(ssp->clk);
1539
1540 /* Restore LPSS private register bits */
1541 if (is_lpss_ssp(drv_data))
1542 lpss_ssp_setup(drv_data);
1543
1544 /* Start the queue running */
1545 status = spi_master_resume(drv_data->master);
1546 if (status != 0) {
1547 dev_err(dev, "problem starting queue (%d)\n", status);
1548 return status;
1549 }
1550
1551 return 0;
1552 }
1553 #endif
1554
1555 #ifdef CONFIG_PM
1556 static int pxa2xx_spi_runtime_suspend(struct device *dev)
1557 {
1558 struct driver_data *drv_data = dev_get_drvdata(dev);
1559
1560 clk_disable_unprepare(drv_data->ssp->clk);
1561 return 0;
1562 }
1563
1564 static int pxa2xx_spi_runtime_resume(struct device *dev)
1565 {
1566 struct driver_data *drv_data = dev_get_drvdata(dev);
1567
1568 clk_prepare_enable(drv_data->ssp->clk);
1569 return 0;
1570 }
1571 #endif
1572
1573 static const struct dev_pm_ops pxa2xx_spi_pm_ops = {
1574 SET_SYSTEM_SLEEP_PM_OPS(pxa2xx_spi_suspend, pxa2xx_spi_resume)
1575 SET_RUNTIME_PM_OPS(pxa2xx_spi_runtime_suspend,
1576 pxa2xx_spi_runtime_resume, NULL)
1577 };
1578
1579 static struct platform_driver driver = {
1580 .driver = {
1581 .name = "pxa2xx-spi",
1582 .pm = &pxa2xx_spi_pm_ops,
1583 .acpi_match_table = ACPI_PTR(pxa2xx_spi_acpi_match),
1584 },
1585 .probe = pxa2xx_spi_probe,
1586 .remove = pxa2xx_spi_remove,
1587 .shutdown = pxa2xx_spi_shutdown,
1588 };
1589
1590 static int __init pxa2xx_spi_init(void)
1591 {
1592 return platform_driver_register(&driver);
1593 }
1594 subsys_initcall(pxa2xx_spi_init);
1595
1596 static void __exit pxa2xx_spi_exit(void)
1597 {
1598 platform_driver_unregister(&driver);
1599 }
1600 module_exit(pxa2xx_spi_exit);
Linux kernel - Deliverables
This page took 0.075781 seconds and 5 git commands to generate.