xref: /openbmc/linux/drivers/spi/spi-pxa2xx.c (revision 110e6f26)
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/bitops.h>
17 #include <linux/init.h>
18 #include <linux/module.h>
19 #include <linux/device.h>
20 #include <linux/ioport.h>
21 #include <linux/errno.h>
22 #include <linux/err.h>
23 #include <linux/interrupt.h>
24 #include <linux/kernel.h>
25 #include <linux/pci.h>
26 #include <linux/platform_device.h>
27 #include <linux/spi/pxa2xx_spi.h>
28 #include <linux/spi/spi.h>
29 #include <linux/delay.h>
30 #include <linux/gpio.h>
31 #include <linux/slab.h>
32 #include <linux/clk.h>
33 #include <linux/pm_runtime.h>
34 #include <linux/acpi.h>
35 
36 #include "spi-pxa2xx.h"
37 
38 MODULE_AUTHOR("Stephen Street");
39 MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
40 MODULE_LICENSE("GPL");
41 MODULE_ALIAS("platform:pxa2xx-spi");
42 
43 #define TIMOUT_DFLT		1000
44 
45 /*
46  * for testing SSCR1 changes that require SSP restart, basically
47  * everything except the service and interrupt enables, the pxa270 developer
48  * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
49  * list, but the PXA255 dev man says all bits without really meaning the
50  * service and interrupt enables
51  */
52 #define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
53 				| SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
54 				| SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
55 				| SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
56 				| SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
57 				| SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
58 
59 #define QUARK_X1000_SSCR1_CHANGE_MASK (QUARK_X1000_SSCR1_STRF	\
60 				| QUARK_X1000_SSCR1_EFWR	\
61 				| QUARK_X1000_SSCR1_RFT		\
62 				| QUARK_X1000_SSCR1_TFT		\
63 				| SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
64 
65 #define LPSS_GENERAL_REG_RXTO_HOLDOFF_DISABLE	BIT(24)
66 #define LPSS_CS_CONTROL_SW_MODE			BIT(0)
67 #define LPSS_CS_CONTROL_CS_HIGH			BIT(1)
68 #define LPSS_CAPS_CS_EN_SHIFT			9
69 #define LPSS_CAPS_CS_EN_MASK			(0xf << LPSS_CAPS_CS_EN_SHIFT)
70 
71 struct lpss_config {
72 	/* LPSS offset from drv_data->ioaddr */
73 	unsigned offset;
74 	/* Register offsets from drv_data->lpss_base or -1 */
75 	int reg_general;
76 	int reg_ssp;
77 	int reg_cs_ctrl;
78 	int reg_capabilities;
79 	/* FIFO thresholds */
80 	u32 rx_threshold;
81 	u32 tx_threshold_lo;
82 	u32 tx_threshold_hi;
83 	/* Chip select control */
84 	unsigned cs_sel_shift;
85 	unsigned cs_sel_mask;
86 	unsigned cs_num;
87 };
88 
89 /* Keep these sorted with enum pxa_ssp_type */
90 static const struct lpss_config lpss_platforms[] = {
91 	{	/* LPSS_LPT_SSP */
92 		.offset = 0x800,
93 		.reg_general = 0x08,
94 		.reg_ssp = 0x0c,
95 		.reg_cs_ctrl = 0x18,
96 		.reg_capabilities = -1,
97 		.rx_threshold = 64,
98 		.tx_threshold_lo = 160,
99 		.tx_threshold_hi = 224,
100 	},
101 	{	/* LPSS_BYT_SSP */
102 		.offset = 0x400,
103 		.reg_general = 0x08,
104 		.reg_ssp = 0x0c,
105 		.reg_cs_ctrl = 0x18,
106 		.reg_capabilities = -1,
107 		.rx_threshold = 64,
108 		.tx_threshold_lo = 160,
109 		.tx_threshold_hi = 224,
110 	},
111 	{	/* LPSS_BSW_SSP */
112 		.offset = 0x400,
113 		.reg_general = 0x08,
114 		.reg_ssp = 0x0c,
115 		.reg_cs_ctrl = 0x18,
116 		.reg_capabilities = -1,
117 		.rx_threshold = 64,
118 		.tx_threshold_lo = 160,
119 		.tx_threshold_hi = 224,
120 		.cs_sel_shift = 2,
121 		.cs_sel_mask = 1 << 2,
122 		.cs_num = 2,
123 	},
124 	{	/* LPSS_SPT_SSP */
125 		.offset = 0x200,
126 		.reg_general = -1,
127 		.reg_ssp = 0x20,
128 		.reg_cs_ctrl = 0x24,
129 		.reg_capabilities = 0xfc,
130 		.rx_threshold = 1,
131 		.tx_threshold_lo = 32,
132 		.tx_threshold_hi = 56,
133 	},
134 	{	/* LPSS_BXT_SSP */
135 		.offset = 0x200,
136 		.reg_general = -1,
137 		.reg_ssp = 0x20,
138 		.reg_cs_ctrl = 0x24,
139 		.reg_capabilities = 0xfc,
140 		.rx_threshold = 1,
141 		.tx_threshold_lo = 16,
142 		.tx_threshold_hi = 48,
143 		.cs_sel_shift = 8,
144 		.cs_sel_mask = 3 << 8,
145 	},
146 };
147 
148 static inline const struct lpss_config
149 *lpss_get_config(const struct driver_data *drv_data)
150 {
151 	return &lpss_platforms[drv_data->ssp_type - LPSS_LPT_SSP];
152 }
153 
154 static bool is_lpss_ssp(const struct driver_data *drv_data)
155 {
156 	switch (drv_data->ssp_type) {
157 	case LPSS_LPT_SSP:
158 	case LPSS_BYT_SSP:
159 	case LPSS_BSW_SSP:
160 	case LPSS_SPT_SSP:
161 	case LPSS_BXT_SSP:
162 		return true;
163 	default:
164 		return false;
165 	}
166 }
167 
168 static bool is_quark_x1000_ssp(const struct driver_data *drv_data)
169 {
170 	return drv_data->ssp_type == QUARK_X1000_SSP;
171 }
172 
173 static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
174 {
175 	switch (drv_data->ssp_type) {
176 	case QUARK_X1000_SSP:
177 		return QUARK_X1000_SSCR1_CHANGE_MASK;
178 	default:
179 		return SSCR1_CHANGE_MASK;
180 	}
181 }
182 
183 static u32
184 pxa2xx_spi_get_rx_default_thre(const struct driver_data *drv_data)
185 {
186 	switch (drv_data->ssp_type) {
187 	case QUARK_X1000_SSP:
188 		return RX_THRESH_QUARK_X1000_DFLT;
189 	default:
190 		return RX_THRESH_DFLT;
191 	}
192 }
193 
194 static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
195 {
196 	u32 mask;
197 
198 	switch (drv_data->ssp_type) {
199 	case QUARK_X1000_SSP:
200 		mask = QUARK_X1000_SSSR_TFL_MASK;
201 		break;
202 	default:
203 		mask = SSSR_TFL_MASK;
204 		break;
205 	}
206 
207 	return (pxa2xx_spi_read(drv_data, SSSR) & mask) == mask;
208 }
209 
210 static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
211 				     u32 *sccr1_reg)
212 {
213 	u32 mask;
214 
215 	switch (drv_data->ssp_type) {
216 	case QUARK_X1000_SSP:
217 		mask = QUARK_X1000_SSCR1_RFT;
218 		break;
219 	default:
220 		mask = SSCR1_RFT;
221 		break;
222 	}
223 	*sccr1_reg &= ~mask;
224 }
225 
226 static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
227 				   u32 *sccr1_reg, u32 threshold)
228 {
229 	switch (drv_data->ssp_type) {
230 	case QUARK_X1000_SSP:
231 		*sccr1_reg |= QUARK_X1000_SSCR1_RxTresh(threshold);
232 		break;
233 	default:
234 		*sccr1_reg |= SSCR1_RxTresh(threshold);
235 		break;
236 	}
237 }
238 
239 static u32 pxa2xx_configure_sscr0(const struct driver_data *drv_data,
240 				  u32 clk_div, u8 bits)
241 {
242 	switch (drv_data->ssp_type) {
243 	case QUARK_X1000_SSP:
244 		return clk_div
245 			| QUARK_X1000_SSCR0_Motorola
246 			| QUARK_X1000_SSCR0_DataSize(bits > 32 ? 8 : bits)
247 			| SSCR0_SSE;
248 	default:
249 		return clk_div
250 			| SSCR0_Motorola
251 			| SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
252 			| SSCR0_SSE
253 			| (bits > 16 ? SSCR0_EDSS : 0);
254 	}
255 }
256 
257 /*
258  * Read and write LPSS SSP private registers. Caller must first check that
259  * is_lpss_ssp() returns true before these can be called.
260  */
261 static u32 __lpss_ssp_read_priv(struct driver_data *drv_data, unsigned offset)
262 {
263 	WARN_ON(!drv_data->lpss_base);
264 	return readl(drv_data->lpss_base + offset);
265 }
266 
267 static void __lpss_ssp_write_priv(struct driver_data *drv_data,
268 				  unsigned offset, u32 value)
269 {
270 	WARN_ON(!drv_data->lpss_base);
271 	writel(value, drv_data->lpss_base + offset);
272 }
273 
274 /*
275  * lpss_ssp_setup - perform LPSS SSP specific setup
276  * @drv_data: pointer to the driver private data
277  *
278  * Perform LPSS SSP specific setup. This function must be called first if
279  * one is going to use LPSS SSP private registers.
280  */
281 static void lpss_ssp_setup(struct driver_data *drv_data)
282 {
283 	const struct lpss_config *config;
284 	u32 value;
285 
286 	config = lpss_get_config(drv_data);
287 	drv_data->lpss_base = drv_data->ioaddr + config->offset;
288 
289 	/* Enable software chip select control */
290 	value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
291 	value &= ~(LPSS_CS_CONTROL_SW_MODE | LPSS_CS_CONTROL_CS_HIGH);
292 	value |= LPSS_CS_CONTROL_SW_MODE | LPSS_CS_CONTROL_CS_HIGH;
293 	__lpss_ssp_write_priv(drv_data, config->reg_cs_ctrl, value);
294 
295 	/* Enable multiblock DMA transfers */
296 	if (drv_data->master_info->enable_dma) {
297 		__lpss_ssp_write_priv(drv_data, config->reg_ssp, 1);
298 
299 		if (config->reg_general >= 0) {
300 			value = __lpss_ssp_read_priv(drv_data,
301 						     config->reg_general);
302 			value |= LPSS_GENERAL_REG_RXTO_HOLDOFF_DISABLE;
303 			__lpss_ssp_write_priv(drv_data,
304 					      config->reg_general, value);
305 		}
306 	}
307 }
308 
309 static void lpss_ssp_select_cs(struct driver_data *drv_data,
310 			       const struct lpss_config *config)
311 {
312 	u32 value, cs;
313 
314 	if (!config->cs_sel_mask)
315 		return;
316 
317 	value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
318 
319 	cs = drv_data->cur_msg->spi->chip_select;
320 	cs <<= config->cs_sel_shift;
321 	if (cs != (value & config->cs_sel_mask)) {
322 		/*
323 		 * When switching another chip select output active the
324 		 * output must be selected first and wait 2 ssp_clk cycles
325 		 * before changing state to active. Otherwise a short
326 		 * glitch will occur on the previous chip select since
327 		 * output select is latched but state control is not.
328 		 */
329 		value &= ~config->cs_sel_mask;
330 		value |= cs;
331 		__lpss_ssp_write_priv(drv_data,
332 				      config->reg_cs_ctrl, value);
333 		ndelay(1000000000 /
334 		       (drv_data->master->max_speed_hz / 2));
335 	}
336 }
337 
338 static void lpss_ssp_cs_control(struct driver_data *drv_data, bool enable)
339 {
340 	const struct lpss_config *config;
341 	u32 value;
342 
343 	config = lpss_get_config(drv_data);
344 
345 	if (enable)
346 		lpss_ssp_select_cs(drv_data, config);
347 
348 	value = __lpss_ssp_read_priv(drv_data, config->reg_cs_ctrl);
349 	if (enable)
350 		value &= ~LPSS_CS_CONTROL_CS_HIGH;
351 	else
352 		value |= LPSS_CS_CONTROL_CS_HIGH;
353 	__lpss_ssp_write_priv(drv_data, config->reg_cs_ctrl, value);
354 }
355 
356 static void cs_assert(struct driver_data *drv_data)
357 {
358 	struct chip_data *chip = drv_data->cur_chip;
359 
360 	if (drv_data->ssp_type == CE4100_SSP) {
361 		pxa2xx_spi_write(drv_data, SSSR, drv_data->cur_chip->frm);
362 		return;
363 	}
364 
365 	if (chip->cs_control) {
366 		chip->cs_control(PXA2XX_CS_ASSERT);
367 		return;
368 	}
369 
370 	if (gpio_is_valid(chip->gpio_cs)) {
371 		gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
372 		return;
373 	}
374 
375 	if (is_lpss_ssp(drv_data))
376 		lpss_ssp_cs_control(drv_data, true);
377 }
378 
379 static void cs_deassert(struct driver_data *drv_data)
380 {
381 	struct chip_data *chip = drv_data->cur_chip;
382 
383 	if (drv_data->ssp_type == CE4100_SSP)
384 		return;
385 
386 	if (chip->cs_control) {
387 		chip->cs_control(PXA2XX_CS_DEASSERT);
388 		return;
389 	}
390 
391 	if (gpio_is_valid(chip->gpio_cs)) {
392 		gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
393 		return;
394 	}
395 
396 	if (is_lpss_ssp(drv_data))
397 		lpss_ssp_cs_control(drv_data, false);
398 }
399 
400 int pxa2xx_spi_flush(struct driver_data *drv_data)
401 {
402 	unsigned long limit = loops_per_jiffy << 1;
403 
404 	do {
405 		while (pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
406 			pxa2xx_spi_read(drv_data, SSDR);
407 	} while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY) && --limit);
408 	write_SSSR_CS(drv_data, SSSR_ROR);
409 
410 	return limit;
411 }
412 
413 static int null_writer(struct driver_data *drv_data)
414 {
415 	u8 n_bytes = drv_data->n_bytes;
416 
417 	if (pxa2xx_spi_txfifo_full(drv_data)
418 		|| (drv_data->tx == drv_data->tx_end))
419 		return 0;
420 
421 	pxa2xx_spi_write(drv_data, SSDR, 0);
422 	drv_data->tx += n_bytes;
423 
424 	return 1;
425 }
426 
427 static int null_reader(struct driver_data *drv_data)
428 {
429 	u8 n_bytes = drv_data->n_bytes;
430 
431 	while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
432 	       && (drv_data->rx < drv_data->rx_end)) {
433 		pxa2xx_spi_read(drv_data, SSDR);
434 		drv_data->rx += n_bytes;
435 	}
436 
437 	return drv_data->rx == drv_data->rx_end;
438 }
439 
440 static int u8_writer(struct driver_data *drv_data)
441 {
442 	if (pxa2xx_spi_txfifo_full(drv_data)
443 		|| (drv_data->tx == drv_data->tx_end))
444 		return 0;
445 
446 	pxa2xx_spi_write(drv_data, SSDR, *(u8 *)(drv_data->tx));
447 	++drv_data->tx;
448 
449 	return 1;
450 }
451 
452 static int u8_reader(struct driver_data *drv_data)
453 {
454 	while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
455 	       && (drv_data->rx < drv_data->rx_end)) {
456 		*(u8 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
457 		++drv_data->rx;
458 	}
459 
460 	return drv_data->rx == drv_data->rx_end;
461 }
462 
463 static int u16_writer(struct driver_data *drv_data)
464 {
465 	if (pxa2xx_spi_txfifo_full(drv_data)
466 		|| (drv_data->tx == drv_data->tx_end))
467 		return 0;
468 
469 	pxa2xx_spi_write(drv_data, SSDR, *(u16 *)(drv_data->tx));
470 	drv_data->tx += 2;
471 
472 	return 1;
473 }
474 
475 static int u16_reader(struct driver_data *drv_data)
476 {
477 	while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
478 	       && (drv_data->rx < drv_data->rx_end)) {
479 		*(u16 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
480 		drv_data->rx += 2;
481 	}
482 
483 	return drv_data->rx == drv_data->rx_end;
484 }
485 
486 static int u32_writer(struct driver_data *drv_data)
487 {
488 	if (pxa2xx_spi_txfifo_full(drv_data)
489 		|| (drv_data->tx == drv_data->tx_end))
490 		return 0;
491 
492 	pxa2xx_spi_write(drv_data, SSDR, *(u32 *)(drv_data->tx));
493 	drv_data->tx += 4;
494 
495 	return 1;
496 }
497 
498 static int u32_reader(struct driver_data *drv_data)
499 {
500 	while ((pxa2xx_spi_read(drv_data, SSSR) & SSSR_RNE)
501 	       && (drv_data->rx < drv_data->rx_end)) {
502 		*(u32 *)(drv_data->rx) = pxa2xx_spi_read(drv_data, SSDR);
503 		drv_data->rx += 4;
504 	}
505 
506 	return drv_data->rx == drv_data->rx_end;
507 }
508 
509 void *pxa2xx_spi_next_transfer(struct driver_data *drv_data)
510 {
511 	struct spi_message *msg = drv_data->cur_msg;
512 	struct spi_transfer *trans = drv_data->cur_transfer;
513 
514 	/* Move to next transfer */
515 	if (trans->transfer_list.next != &msg->transfers) {
516 		drv_data->cur_transfer =
517 			list_entry(trans->transfer_list.next,
518 					struct spi_transfer,
519 					transfer_list);
520 		return RUNNING_STATE;
521 	} else
522 		return DONE_STATE;
523 }
524 
525 /* caller already set message->status; dma and pio irqs are blocked */
526 static void giveback(struct driver_data *drv_data)
527 {
528 	struct spi_transfer* last_transfer;
529 	struct spi_message *msg;
530 	unsigned long timeout;
531 
532 	msg = drv_data->cur_msg;
533 	drv_data->cur_msg = NULL;
534 	drv_data->cur_transfer = NULL;
535 
536 	last_transfer = list_last_entry(&msg->transfers, struct spi_transfer,
537 					transfer_list);
538 
539 	/* Delay if requested before any change in chip select */
540 	if (last_transfer->delay_usecs)
541 		udelay(last_transfer->delay_usecs);
542 
543 	/* Wait until SSP becomes idle before deasserting the CS */
544 	timeout = jiffies + msecs_to_jiffies(10);
545 	while (pxa2xx_spi_read(drv_data, SSSR) & SSSR_BSY &&
546 	       !time_after(jiffies, timeout))
547 		cpu_relax();
548 
549 	/* Drop chip select UNLESS cs_change is true or we are returning
550 	 * a message with an error, or next message is for another chip
551 	 */
552 	if (!last_transfer->cs_change)
553 		cs_deassert(drv_data);
554 	else {
555 		struct spi_message *next_msg;
556 
557 		/* Holding of cs was hinted, but we need to make sure
558 		 * the next message is for the same chip.  Don't waste
559 		 * time with the following tests unless this was hinted.
560 		 *
561 		 * We cannot postpone this until pump_messages, because
562 		 * after calling msg->complete (below) the driver that
563 		 * sent the current message could be unloaded, which
564 		 * could invalidate the cs_control() callback...
565 		 */
566 
567 		/* get a pointer to the next message, if any */
568 		next_msg = spi_get_next_queued_message(drv_data->master);
569 
570 		/* see if the next and current messages point
571 		 * to the same chip
572 		 */
573 		if (next_msg && next_msg->spi != msg->spi)
574 			next_msg = NULL;
575 		if (!next_msg || msg->state == ERROR_STATE)
576 			cs_deassert(drv_data);
577 	}
578 
579 	drv_data->cur_chip = NULL;
580 	spi_finalize_current_message(drv_data->master);
581 }
582 
583 static void reset_sccr1(struct driver_data *drv_data)
584 {
585 	struct chip_data *chip = drv_data->cur_chip;
586 	u32 sccr1_reg;
587 
588 	sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1) & ~drv_data->int_cr1;
589 	sccr1_reg &= ~SSCR1_RFT;
590 	sccr1_reg |= chip->threshold;
591 	pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg);
592 }
593 
594 static void int_error_stop(struct driver_data *drv_data, const char* msg)
595 {
596 	/* Stop and reset SSP */
597 	write_SSSR_CS(drv_data, drv_data->clear_sr);
598 	reset_sccr1(drv_data);
599 	if (!pxa25x_ssp_comp(drv_data))
600 		pxa2xx_spi_write(drv_data, SSTO, 0);
601 	pxa2xx_spi_flush(drv_data);
602 	pxa2xx_spi_write(drv_data, SSCR0,
603 			 pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
604 
605 	dev_err(&drv_data->pdev->dev, "%s\n", msg);
606 
607 	drv_data->cur_msg->state = ERROR_STATE;
608 	tasklet_schedule(&drv_data->pump_transfers);
609 }
610 
611 static void int_transfer_complete(struct driver_data *drv_data)
612 {
613 	/* Clear and disable interrupts */
614 	write_SSSR_CS(drv_data, drv_data->clear_sr);
615 	reset_sccr1(drv_data);
616 	if (!pxa25x_ssp_comp(drv_data))
617 		pxa2xx_spi_write(drv_data, SSTO, 0);
618 
619 	/* Update total byte transferred return count actual bytes read */
620 	drv_data->cur_msg->actual_length += drv_data->len -
621 				(drv_data->rx_end - drv_data->rx);
622 
623 	/* Transfer delays and chip select release are
624 	 * handled in pump_transfers or giveback
625 	 */
626 
627 	/* Move to next transfer */
628 	drv_data->cur_msg->state = pxa2xx_spi_next_transfer(drv_data);
629 
630 	/* Schedule transfer tasklet */
631 	tasklet_schedule(&drv_data->pump_transfers);
632 }
633 
634 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
635 {
636 	u32 irq_mask = (pxa2xx_spi_read(drv_data, SSCR1) & SSCR1_TIE) ?
637 		       drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
638 
639 	u32 irq_status = pxa2xx_spi_read(drv_data, SSSR) & irq_mask;
640 
641 	if (irq_status & SSSR_ROR) {
642 		int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
643 		return IRQ_HANDLED;
644 	}
645 
646 	if (irq_status & SSSR_TINT) {
647 		pxa2xx_spi_write(drv_data, SSSR, SSSR_TINT);
648 		if (drv_data->read(drv_data)) {
649 			int_transfer_complete(drv_data);
650 			return IRQ_HANDLED;
651 		}
652 	}
653 
654 	/* Drain rx fifo, Fill tx fifo and prevent overruns */
655 	do {
656 		if (drv_data->read(drv_data)) {
657 			int_transfer_complete(drv_data);
658 			return IRQ_HANDLED;
659 		}
660 	} while (drv_data->write(drv_data));
661 
662 	if (drv_data->read(drv_data)) {
663 		int_transfer_complete(drv_data);
664 		return IRQ_HANDLED;
665 	}
666 
667 	if (drv_data->tx == drv_data->tx_end) {
668 		u32 bytes_left;
669 		u32 sccr1_reg;
670 
671 		sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1);
672 		sccr1_reg &= ~SSCR1_TIE;
673 
674 		/*
675 		 * PXA25x_SSP has no timeout, set up rx threshould for the
676 		 * remaining RX bytes.
677 		 */
678 		if (pxa25x_ssp_comp(drv_data)) {
679 			u32 rx_thre;
680 
681 			pxa2xx_spi_clear_rx_thre(drv_data, &sccr1_reg);
682 
683 			bytes_left = drv_data->rx_end - drv_data->rx;
684 			switch (drv_data->n_bytes) {
685 			case 4:
686 				bytes_left >>= 1;
687 			case 2:
688 				bytes_left >>= 1;
689 			}
690 
691 			rx_thre = pxa2xx_spi_get_rx_default_thre(drv_data);
692 			if (rx_thre > bytes_left)
693 				rx_thre = bytes_left;
694 
695 			pxa2xx_spi_set_rx_thre(drv_data, &sccr1_reg, rx_thre);
696 		}
697 		pxa2xx_spi_write(drv_data, SSCR1, sccr1_reg);
698 	}
699 
700 	/* We did something */
701 	return IRQ_HANDLED;
702 }
703 
704 static irqreturn_t ssp_int(int irq, void *dev_id)
705 {
706 	struct driver_data *drv_data = dev_id;
707 	u32 sccr1_reg;
708 	u32 mask = drv_data->mask_sr;
709 	u32 status;
710 
711 	/*
712 	 * The IRQ might be shared with other peripherals so we must first
713 	 * check that are we RPM suspended or not. If we are we assume that
714 	 * the IRQ was not for us (we shouldn't be RPM suspended when the
715 	 * interrupt is enabled).
716 	 */
717 	if (pm_runtime_suspended(&drv_data->pdev->dev))
718 		return IRQ_NONE;
719 
720 	/*
721 	 * If the device is not yet in RPM suspended state and we get an
722 	 * interrupt that is meant for another device, check if status bits
723 	 * are all set to one. That means that the device is already
724 	 * powered off.
725 	 */
726 	status = pxa2xx_spi_read(drv_data, SSSR);
727 	if (status == ~0)
728 		return IRQ_NONE;
729 
730 	sccr1_reg = pxa2xx_spi_read(drv_data, SSCR1);
731 
732 	/* Ignore possible writes if we don't need to write */
733 	if (!(sccr1_reg & SSCR1_TIE))
734 		mask &= ~SSSR_TFS;
735 
736 	/* Ignore RX timeout interrupt if it is disabled */
737 	if (!(sccr1_reg & SSCR1_TINTE))
738 		mask &= ~SSSR_TINT;
739 
740 	if (!(status & mask))
741 		return IRQ_NONE;
742 
743 	if (!drv_data->cur_msg) {
744 
745 		pxa2xx_spi_write(drv_data, SSCR0,
746 				 pxa2xx_spi_read(drv_data, SSCR0)
747 				 & ~SSCR0_SSE);
748 		pxa2xx_spi_write(drv_data, SSCR1,
749 				 pxa2xx_spi_read(drv_data, SSCR1)
750 				 & ~drv_data->int_cr1);
751 		if (!pxa25x_ssp_comp(drv_data))
752 			pxa2xx_spi_write(drv_data, SSTO, 0);
753 		write_SSSR_CS(drv_data, drv_data->clear_sr);
754 
755 		dev_err(&drv_data->pdev->dev,
756 			"bad message state in interrupt handler\n");
757 
758 		/* Never fail */
759 		return IRQ_HANDLED;
760 	}
761 
762 	return drv_data->transfer_handler(drv_data);
763 }
764 
765 /*
766  * The Quark SPI has an additional 24 bit register (DDS_CLK_RATE) to multiply
767  * input frequency by fractions of 2^24. It also has a divider by 5.
768  *
769  * There are formulas to get baud rate value for given input frequency and
770  * divider parameters, such as DDS_CLK_RATE and SCR:
771  *
772  * Fsys = 200MHz
773  *
774  * Fssp = Fsys * DDS_CLK_RATE / 2^24			(1)
775  * Baud rate = Fsclk = Fssp / (2 * (SCR + 1))		(2)
776  *
777  * DDS_CLK_RATE either 2^n or 2^n / 5.
778  * SCR is in range 0 .. 255
779  *
780  * Divisor = 5^i * 2^j * 2 * k
781  *       i = [0, 1]      i = 1 iff j = 0 or j > 3
782  *       j = [0, 23]     j = 0 iff i = 1
783  *       k = [1, 256]
784  * Special case: j = 0, i = 1: Divisor = 2 / 5
785  *
786  * Accordingly to the specification the recommended values for DDS_CLK_RATE
787  * are:
788  *	Case 1:		2^n, n = [0, 23]
789  *	Case 2:		2^24 * 2 / 5 (0x666666)
790  *	Case 3:		less than or equal to 2^24 / 5 / 16 (0x33333)
791  *
792  * In all cases the lowest possible value is better.
793  *
794  * The function calculates parameters for all cases and chooses the one closest
795  * to the asked baud rate.
796  */
797 static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds)
798 {
799 	unsigned long xtal = 200000000;
800 	unsigned long fref = xtal / 2;		/* mandatory division by 2,
801 						   see (2) */
802 						/* case 3 */
803 	unsigned long fref1 = fref / 2;		/* case 1 */
804 	unsigned long fref2 = fref * 2 / 5;	/* case 2 */
805 	unsigned long scale;
806 	unsigned long q, q1, q2;
807 	long r, r1, r2;
808 	u32 mul;
809 
810 	/* Case 1 */
811 
812 	/* Set initial value for DDS_CLK_RATE */
813 	mul = (1 << 24) >> 1;
814 
815 	/* Calculate initial quot */
816 	q1 = DIV_ROUND_UP(fref1, rate);
817 
818 	/* Scale q1 if it's too big */
819 	if (q1 > 256) {
820 		/* Scale q1 to range [1, 512] */
821 		scale = fls_long(q1 - 1);
822 		if (scale > 9) {
823 			q1 >>= scale - 9;
824 			mul >>= scale - 9;
825 		}
826 
827 		/* Round the result if we have a remainder */
828 		q1 += q1 & 1;
829 	}
830 
831 	/* Decrease DDS_CLK_RATE as much as we can without loss in precision */
832 	scale = __ffs(q1);
833 	q1 >>= scale;
834 	mul >>= scale;
835 
836 	/* Get the remainder */
837 	r1 = abs(fref1 / (1 << (24 - fls_long(mul))) / q1 - rate);
838 
839 	/* Case 2 */
840 
841 	q2 = DIV_ROUND_UP(fref2, rate);
842 	r2 = abs(fref2 / q2 - rate);
843 
844 	/*
845 	 * Choose the best between two: less remainder we have the better. We
846 	 * can't go case 2 if q2 is greater than 256 since SCR register can
847 	 * hold only values 0 .. 255.
848 	 */
849 	if (r2 >= r1 || q2 > 256) {
850 		/* case 1 is better */
851 		r = r1;
852 		q = q1;
853 	} else {
854 		/* case 2 is better */
855 		r = r2;
856 		q = q2;
857 		mul = (1 << 24) * 2 / 5;
858 	}
859 
860 	/* Check case 3 only if the divisor is big enough */
861 	if (fref / rate >= 80) {
862 		u64 fssp;
863 		u32 m;
864 
865 		/* Calculate initial quot */
866 		q1 = DIV_ROUND_UP(fref, rate);
867 		m = (1 << 24) / q1;
868 
869 		/* Get the remainder */
870 		fssp = (u64)fref * m;
871 		do_div(fssp, 1 << 24);
872 		r1 = abs(fssp - rate);
873 
874 		/* Choose this one if it suits better */
875 		if (r1 < r) {
876 			/* case 3 is better */
877 			q = 1;
878 			mul = m;
879 		}
880 	}
881 
882 	*dds = mul;
883 	return q - 1;
884 }
885 
886 static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
887 {
888 	unsigned long ssp_clk = drv_data->master->max_speed_hz;
889 	const struct ssp_device *ssp = drv_data->ssp;
890 
891 	rate = min_t(int, ssp_clk, rate);
892 
893 	if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP)
894 		return (ssp_clk / (2 * rate) - 1) & 0xff;
895 	else
896 		return (ssp_clk / rate - 1) & 0xfff;
897 }
898 
899 static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data,
900 					   int rate)
901 {
902 	struct chip_data *chip = drv_data->cur_chip;
903 	unsigned int clk_div;
904 
905 	switch (drv_data->ssp_type) {
906 	case QUARK_X1000_SSP:
907 		clk_div = quark_x1000_get_clk_div(rate, &chip->dds_rate);
908 		break;
909 	default:
910 		clk_div = ssp_get_clk_div(drv_data, rate);
911 		break;
912 	}
913 	return clk_div << 8;
914 }
915 
916 static void pump_transfers(unsigned long data)
917 {
918 	struct driver_data *drv_data = (struct driver_data *)data;
919 	struct spi_message *message = NULL;
920 	struct spi_transfer *transfer = NULL;
921 	struct spi_transfer *previous = NULL;
922 	struct chip_data *chip = NULL;
923 	u32 clk_div = 0;
924 	u8 bits = 0;
925 	u32 speed = 0;
926 	u32 cr0;
927 	u32 cr1;
928 	u32 dma_thresh = drv_data->cur_chip->dma_threshold;
929 	u32 dma_burst = drv_data->cur_chip->dma_burst_size;
930 	u32 change_mask = pxa2xx_spi_get_ssrc1_change_mask(drv_data);
931 
932 	/* Get current state information */
933 	message = drv_data->cur_msg;
934 	transfer = drv_data->cur_transfer;
935 	chip = drv_data->cur_chip;
936 
937 	/* Handle for abort */
938 	if (message->state == ERROR_STATE) {
939 		message->status = -EIO;
940 		giveback(drv_data);
941 		return;
942 	}
943 
944 	/* Handle end of message */
945 	if (message->state == DONE_STATE) {
946 		message->status = 0;
947 		giveback(drv_data);
948 		return;
949 	}
950 
951 	/* Delay if requested at end of transfer before CS change */
952 	if (message->state == RUNNING_STATE) {
953 		previous = list_entry(transfer->transfer_list.prev,
954 					struct spi_transfer,
955 					transfer_list);
956 		if (previous->delay_usecs)
957 			udelay(previous->delay_usecs);
958 
959 		/* Drop chip select only if cs_change is requested */
960 		if (previous->cs_change)
961 			cs_deassert(drv_data);
962 	}
963 
964 	/* Check if we can DMA this transfer */
965 	if (!pxa2xx_spi_dma_is_possible(transfer->len) && chip->enable_dma) {
966 
967 		/* reject already-mapped transfers; PIO won't always work */
968 		if (message->is_dma_mapped
969 				|| transfer->rx_dma || transfer->tx_dma) {
970 			dev_err(&drv_data->pdev->dev,
971 				"pump_transfers: mapped transfer length of "
972 				"%u is greater than %d\n",
973 				transfer->len, MAX_DMA_LEN);
974 			message->status = -EINVAL;
975 			giveback(drv_data);
976 			return;
977 		}
978 
979 		/* warn ... we force this to PIO mode */
980 		dev_warn_ratelimited(&message->spi->dev,
981 				     "pump_transfers: DMA disabled for transfer length %ld "
982 				     "greater than %d\n",
983 				     (long)drv_data->len, MAX_DMA_LEN);
984 	}
985 
986 	/* Setup the transfer state based on the type of transfer */
987 	if (pxa2xx_spi_flush(drv_data) == 0) {
988 		dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
989 		message->status = -EIO;
990 		giveback(drv_data);
991 		return;
992 	}
993 	drv_data->n_bytes = chip->n_bytes;
994 	drv_data->tx = (void *)transfer->tx_buf;
995 	drv_data->tx_end = drv_data->tx + transfer->len;
996 	drv_data->rx = transfer->rx_buf;
997 	drv_data->rx_end = drv_data->rx + transfer->len;
998 	drv_data->len = transfer->len;
999 	drv_data->write = drv_data->tx ? chip->write : null_writer;
1000 	drv_data->read = drv_data->rx ? chip->read : null_reader;
1001 
1002 	/* Change speed and bit per word on a per transfer */
1003 	bits = transfer->bits_per_word;
1004 	speed = transfer->speed_hz;
1005 
1006 	clk_div = pxa2xx_ssp_get_clk_div(drv_data, speed);
1007 
1008 	if (bits <= 8) {
1009 		drv_data->n_bytes = 1;
1010 		drv_data->read = drv_data->read != null_reader ?
1011 					u8_reader : null_reader;
1012 		drv_data->write = drv_data->write != null_writer ?
1013 					u8_writer : null_writer;
1014 	} else if (bits <= 16) {
1015 		drv_data->n_bytes = 2;
1016 		drv_data->read = drv_data->read != null_reader ?
1017 					u16_reader : null_reader;
1018 		drv_data->write = drv_data->write != null_writer ?
1019 					u16_writer : null_writer;
1020 	} else if (bits <= 32) {
1021 		drv_data->n_bytes = 4;
1022 		drv_data->read = drv_data->read != null_reader ?
1023 					u32_reader : null_reader;
1024 		drv_data->write = drv_data->write != null_writer ?
1025 					u32_writer : null_writer;
1026 	}
1027 	/*
1028 	 * if bits/word is changed in dma mode, then must check the
1029 	 * thresholds and burst also
1030 	 */
1031 	if (chip->enable_dma) {
1032 		if (pxa2xx_spi_set_dma_burst_and_threshold(chip,
1033 						message->spi,
1034 						bits, &dma_burst,
1035 						&dma_thresh))
1036 			dev_warn_ratelimited(&message->spi->dev,
1037 					     "pump_transfers: DMA burst size reduced to match bits_per_word\n");
1038 	}
1039 
1040 	message->state = RUNNING_STATE;
1041 
1042 	drv_data->dma_mapped = 0;
1043 	if (pxa2xx_spi_dma_is_possible(drv_data->len))
1044 		drv_data->dma_mapped = pxa2xx_spi_map_dma_buffers(drv_data);
1045 	if (drv_data->dma_mapped) {
1046 
1047 		/* Ensure we have the correct interrupt handler */
1048 		drv_data->transfer_handler = pxa2xx_spi_dma_transfer;
1049 
1050 		pxa2xx_spi_dma_prepare(drv_data, dma_burst);
1051 
1052 		/* Clear status and start DMA engine */
1053 		cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
1054 		pxa2xx_spi_write(drv_data, SSSR, drv_data->clear_sr);
1055 
1056 		pxa2xx_spi_dma_start(drv_data);
1057 	} else {
1058 		/* Ensure we have the correct interrupt handler	*/
1059 		drv_data->transfer_handler = interrupt_transfer;
1060 
1061 		/* Clear status  */
1062 		cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
1063 		write_SSSR_CS(drv_data, drv_data->clear_sr);
1064 	}
1065 
1066 	/* NOTE:  PXA25x_SSP _could_ use external clocking ... */
1067 	cr0 = pxa2xx_configure_sscr0(drv_data, clk_div, bits);
1068 	if (!pxa25x_ssp_comp(drv_data))
1069 		dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
1070 			drv_data->master->max_speed_hz
1071 				/ (1 + ((cr0 & SSCR0_SCR(0xfff)) >> 8)),
1072 			drv_data->dma_mapped ? "DMA" : "PIO");
1073 	else
1074 		dev_dbg(&message->spi->dev, "%u Hz actual, %s\n",
1075 			drv_data->master->max_speed_hz / 2
1076 				/ (1 + ((cr0 & SSCR0_SCR(0x0ff)) >> 8)),
1077 			drv_data->dma_mapped ? "DMA" : "PIO");
1078 
1079 	if (is_lpss_ssp(drv_data)) {
1080 		if ((pxa2xx_spi_read(drv_data, SSIRF) & 0xff)
1081 		    != chip->lpss_rx_threshold)
1082 			pxa2xx_spi_write(drv_data, SSIRF,
1083 					 chip->lpss_rx_threshold);
1084 		if ((pxa2xx_spi_read(drv_data, SSITF) & 0xffff)
1085 		    != chip->lpss_tx_threshold)
1086 			pxa2xx_spi_write(drv_data, SSITF,
1087 					 chip->lpss_tx_threshold);
1088 	}
1089 
1090 	if (is_quark_x1000_ssp(drv_data) &&
1091 	    (pxa2xx_spi_read(drv_data, DDS_RATE) != chip->dds_rate))
1092 		pxa2xx_spi_write(drv_data, DDS_RATE, chip->dds_rate);
1093 
1094 	/* see if we need to reload the config registers */
1095 	if ((pxa2xx_spi_read(drv_data, SSCR0) != cr0)
1096 	    || (pxa2xx_spi_read(drv_data, SSCR1) & change_mask)
1097 	    != (cr1 & change_mask)) {
1098 		/* stop the SSP, and update the other bits */
1099 		pxa2xx_spi_write(drv_data, SSCR0, cr0 & ~SSCR0_SSE);
1100 		if (!pxa25x_ssp_comp(drv_data))
1101 			pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
1102 		/* first set CR1 without interrupt and service enables */
1103 		pxa2xx_spi_write(drv_data, SSCR1, cr1 & change_mask);
1104 		/* restart the SSP */
1105 		pxa2xx_spi_write(drv_data, SSCR0, cr0);
1106 
1107 	} else {
1108 		if (!pxa25x_ssp_comp(drv_data))
1109 			pxa2xx_spi_write(drv_data, SSTO, chip->timeout);
1110 	}
1111 
1112 	cs_assert(drv_data);
1113 
1114 	/* after chip select, release the data by enabling service
1115 	 * requests and interrupts, without changing any mode bits */
1116 	pxa2xx_spi_write(drv_data, SSCR1, cr1);
1117 }
1118 
1119 static int pxa2xx_spi_transfer_one_message(struct spi_master *master,
1120 					   struct spi_message *msg)
1121 {
1122 	struct driver_data *drv_data = spi_master_get_devdata(master);
1123 
1124 	drv_data->cur_msg = msg;
1125 	/* Initial message state*/
1126 	drv_data->cur_msg->state = START_STATE;
1127 	drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1128 						struct spi_transfer,
1129 						transfer_list);
1130 
1131 	/* prepare to setup the SSP, in pump_transfers, using the per
1132 	 * chip configuration */
1133 	drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1134 
1135 	/* Mark as busy and launch transfers */
1136 	tasklet_schedule(&drv_data->pump_transfers);
1137 	return 0;
1138 }
1139 
1140 static int pxa2xx_spi_unprepare_transfer(struct spi_master *master)
1141 {
1142 	struct driver_data *drv_data = spi_master_get_devdata(master);
1143 
1144 	/* Disable the SSP now */
1145 	pxa2xx_spi_write(drv_data, SSCR0,
1146 			 pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
1147 
1148 	return 0;
1149 }
1150 
1151 static int setup_cs(struct spi_device *spi, struct chip_data *chip,
1152 		    struct pxa2xx_spi_chip *chip_info)
1153 {
1154 	int err = 0;
1155 
1156 	if (chip == NULL || chip_info == NULL)
1157 		return 0;
1158 
1159 	/* NOTE: setup() can be called multiple times, possibly with
1160 	 * different chip_info, release previously requested GPIO
1161 	 */
1162 	if (gpio_is_valid(chip->gpio_cs))
1163 		gpio_free(chip->gpio_cs);
1164 
1165 	/* If (*cs_control) is provided, ignore GPIO chip select */
1166 	if (chip_info->cs_control) {
1167 		chip->cs_control = chip_info->cs_control;
1168 		return 0;
1169 	}
1170 
1171 	if (gpio_is_valid(chip_info->gpio_cs)) {
1172 		err = gpio_request(chip_info->gpio_cs, "SPI_CS");
1173 		if (err) {
1174 			dev_err(&spi->dev, "failed to request chip select GPIO%d\n",
1175 				chip_info->gpio_cs);
1176 			return err;
1177 		}
1178 
1179 		chip->gpio_cs = chip_info->gpio_cs;
1180 		chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
1181 
1182 		err = gpio_direction_output(chip->gpio_cs,
1183 					!chip->gpio_cs_inverted);
1184 	}
1185 
1186 	return err;
1187 }
1188 
1189 static int setup(struct spi_device *spi)
1190 {
1191 	struct pxa2xx_spi_chip *chip_info = NULL;
1192 	struct chip_data *chip;
1193 	const struct lpss_config *config;
1194 	struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1195 	uint tx_thres, tx_hi_thres, rx_thres;
1196 
1197 	switch (drv_data->ssp_type) {
1198 	case QUARK_X1000_SSP:
1199 		tx_thres = TX_THRESH_QUARK_X1000_DFLT;
1200 		tx_hi_thres = 0;
1201 		rx_thres = RX_THRESH_QUARK_X1000_DFLT;
1202 		break;
1203 	case LPSS_LPT_SSP:
1204 	case LPSS_BYT_SSP:
1205 	case LPSS_BSW_SSP:
1206 	case LPSS_SPT_SSP:
1207 	case LPSS_BXT_SSP:
1208 		config = lpss_get_config(drv_data);
1209 		tx_thres = config->tx_threshold_lo;
1210 		tx_hi_thres = config->tx_threshold_hi;
1211 		rx_thres = config->rx_threshold;
1212 		break;
1213 	default:
1214 		tx_thres = TX_THRESH_DFLT;
1215 		tx_hi_thres = 0;
1216 		rx_thres = RX_THRESH_DFLT;
1217 		break;
1218 	}
1219 
1220 	/* Only alloc on first setup */
1221 	chip = spi_get_ctldata(spi);
1222 	if (!chip) {
1223 		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1224 		if (!chip)
1225 			return -ENOMEM;
1226 
1227 		if (drv_data->ssp_type == CE4100_SSP) {
1228 			if (spi->chip_select > 4) {
1229 				dev_err(&spi->dev,
1230 					"failed setup: cs number must not be > 4.\n");
1231 				kfree(chip);
1232 				return -EINVAL;
1233 			}
1234 
1235 			chip->frm = spi->chip_select;
1236 		} else
1237 			chip->gpio_cs = -1;
1238 		chip->enable_dma = 0;
1239 		chip->timeout = TIMOUT_DFLT;
1240 	}
1241 
1242 	/* protocol drivers may change the chip settings, so...
1243 	 * if chip_info exists, use it */
1244 	chip_info = spi->controller_data;
1245 
1246 	/* chip_info isn't always needed */
1247 	chip->cr1 = 0;
1248 	if (chip_info) {
1249 		if (chip_info->timeout)
1250 			chip->timeout = chip_info->timeout;
1251 		if (chip_info->tx_threshold)
1252 			tx_thres = chip_info->tx_threshold;
1253 		if (chip_info->tx_hi_threshold)
1254 			tx_hi_thres = chip_info->tx_hi_threshold;
1255 		if (chip_info->rx_threshold)
1256 			rx_thres = chip_info->rx_threshold;
1257 		chip->enable_dma = drv_data->master_info->enable_dma;
1258 		chip->dma_threshold = 0;
1259 		if (chip_info->enable_loopback)
1260 			chip->cr1 = SSCR1_LBM;
1261 	} else if (ACPI_HANDLE(&spi->dev)) {
1262 		/*
1263 		 * Slave devices enumerated from ACPI namespace don't
1264 		 * usually have chip_info but we still might want to use
1265 		 * DMA with them.
1266 		 */
1267 		chip->enable_dma = drv_data->master_info->enable_dma;
1268 	}
1269 
1270 	chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);
1271 	chip->lpss_tx_threshold = SSITF_TxLoThresh(tx_thres)
1272 				| SSITF_TxHiThresh(tx_hi_thres);
1273 
1274 	/* set dma burst and threshold outside of chip_info path so that if
1275 	 * chip_info goes away after setting chip->enable_dma, the
1276 	 * burst and threshold can still respond to changes in bits_per_word */
1277 	if (chip->enable_dma) {
1278 		/* set up legal burst and threshold for dma */
1279 		if (pxa2xx_spi_set_dma_burst_and_threshold(chip, spi,
1280 						spi->bits_per_word,
1281 						&chip->dma_burst_size,
1282 						&chip->dma_threshold)) {
1283 			dev_warn(&spi->dev,
1284 				 "in setup: DMA burst size reduced to match bits_per_word\n");
1285 		}
1286 	}
1287 
1288 	switch (drv_data->ssp_type) {
1289 	case QUARK_X1000_SSP:
1290 		chip->threshold = (QUARK_X1000_SSCR1_RxTresh(rx_thres)
1291 				   & QUARK_X1000_SSCR1_RFT)
1292 				   | (QUARK_X1000_SSCR1_TxTresh(tx_thres)
1293 				   & QUARK_X1000_SSCR1_TFT);
1294 		break;
1295 	default:
1296 		chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
1297 			(SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
1298 		break;
1299 	}
1300 
1301 	chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
1302 	chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
1303 			| (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
1304 
1305 	if (spi->mode & SPI_LOOP)
1306 		chip->cr1 |= SSCR1_LBM;
1307 
1308 	if (spi->bits_per_word <= 8) {
1309 		chip->n_bytes = 1;
1310 		chip->read = u8_reader;
1311 		chip->write = u8_writer;
1312 	} else if (spi->bits_per_word <= 16) {
1313 		chip->n_bytes = 2;
1314 		chip->read = u16_reader;
1315 		chip->write = u16_writer;
1316 	} else if (spi->bits_per_word <= 32) {
1317 		chip->n_bytes = 4;
1318 		chip->read = u32_reader;
1319 		chip->write = u32_writer;
1320 	}
1321 
1322 	spi_set_ctldata(spi, chip);
1323 
1324 	if (drv_data->ssp_type == CE4100_SSP)
1325 		return 0;
1326 
1327 	return setup_cs(spi, chip, chip_info);
1328 }
1329 
1330 static void cleanup(struct spi_device *spi)
1331 {
1332 	struct chip_data *chip = spi_get_ctldata(spi);
1333 	struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1334 
1335 	if (!chip)
1336 		return;
1337 
1338 	if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
1339 		gpio_free(chip->gpio_cs);
1340 
1341 	kfree(chip);
1342 }
1343 
1344 #ifdef CONFIG_PCI
1345 #ifdef CONFIG_ACPI
1346 
1347 static const struct acpi_device_id pxa2xx_spi_acpi_match[] = {
1348 	{ "INT33C0", LPSS_LPT_SSP },
1349 	{ "INT33C1", LPSS_LPT_SSP },
1350 	{ "INT3430", LPSS_LPT_SSP },
1351 	{ "INT3431", LPSS_LPT_SSP },
1352 	{ "80860F0E", LPSS_BYT_SSP },
1353 	{ "8086228E", LPSS_BSW_SSP },
1354 	{ },
1355 };
1356 MODULE_DEVICE_TABLE(acpi, pxa2xx_spi_acpi_match);
1357 
1358 static int pxa2xx_spi_get_port_id(struct acpi_device *adev)
1359 {
1360 	unsigned int devid;
1361 	int port_id = -1;
1362 
1363 	if (adev && adev->pnp.unique_id &&
1364 	    !kstrtouint(adev->pnp.unique_id, 0, &devid))
1365 		port_id = devid;
1366 	return port_id;
1367 }
1368 #else /* !CONFIG_ACPI */
1369 static int pxa2xx_spi_get_port_id(struct acpi_device *adev)
1370 {
1371 	return -1;
1372 }
1373 #endif
1374 
1375 /*
1376  * PCI IDs of compound devices that integrate both host controller and private
1377  * integrated DMA engine. Please note these are not used in module
1378  * autoloading and probing in this module but matching the LPSS SSP type.
1379  */
1380 static const struct pci_device_id pxa2xx_spi_pci_compound_match[] = {
1381 	/* SPT-LP */
1382 	{ PCI_VDEVICE(INTEL, 0x9d29), LPSS_SPT_SSP },
1383 	{ PCI_VDEVICE(INTEL, 0x9d2a), LPSS_SPT_SSP },
1384 	/* SPT-H */
1385 	{ PCI_VDEVICE(INTEL, 0xa129), LPSS_SPT_SSP },
1386 	{ PCI_VDEVICE(INTEL, 0xa12a), LPSS_SPT_SSP },
1387 	/* BXT A-Step */
1388 	{ PCI_VDEVICE(INTEL, 0x0ac2), LPSS_BXT_SSP },
1389 	{ PCI_VDEVICE(INTEL, 0x0ac4), LPSS_BXT_SSP },
1390 	{ PCI_VDEVICE(INTEL, 0x0ac6), LPSS_BXT_SSP },
1391 	/* BXT B-Step */
1392 	{ PCI_VDEVICE(INTEL, 0x1ac2), LPSS_BXT_SSP },
1393 	{ PCI_VDEVICE(INTEL, 0x1ac4), LPSS_BXT_SSP },
1394 	{ PCI_VDEVICE(INTEL, 0x1ac6), LPSS_BXT_SSP },
1395 	/* APL */
1396 	{ PCI_VDEVICE(INTEL, 0x5ac2), LPSS_BXT_SSP },
1397 	{ PCI_VDEVICE(INTEL, 0x5ac4), LPSS_BXT_SSP },
1398 	{ PCI_VDEVICE(INTEL, 0x5ac6), LPSS_BXT_SSP },
1399 	{ },
1400 };
1401 
1402 static bool pxa2xx_spi_idma_filter(struct dma_chan *chan, void *param)
1403 {
1404 	struct device *dev = param;
1405 
1406 	if (dev != chan->device->dev->parent)
1407 		return false;
1408 
1409 	return true;
1410 }
1411 
1412 static struct pxa2xx_spi_master *
1413 pxa2xx_spi_init_pdata(struct platform_device *pdev)
1414 {
1415 	struct pxa2xx_spi_master *pdata;
1416 	struct acpi_device *adev;
1417 	struct ssp_device *ssp;
1418 	struct resource *res;
1419 	const struct acpi_device_id *adev_id = NULL;
1420 	const struct pci_device_id *pcidev_id = NULL;
1421 	int type;
1422 
1423 	adev = ACPI_COMPANION(&pdev->dev);
1424 
1425 	if (dev_is_pci(pdev->dev.parent))
1426 		pcidev_id = pci_match_id(pxa2xx_spi_pci_compound_match,
1427 					 to_pci_dev(pdev->dev.parent));
1428 	else if (adev)
1429 		adev_id = acpi_match_device(pdev->dev.driver->acpi_match_table,
1430 					    &pdev->dev);
1431 	else
1432 		return NULL;
1433 
1434 	if (adev_id)
1435 		type = (int)adev_id->driver_data;
1436 	else if (pcidev_id)
1437 		type = (int)pcidev_id->driver_data;
1438 	else
1439 		return NULL;
1440 
1441 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1442 	if (!pdata)
1443 		return NULL;
1444 
1445 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1446 	if (!res)
1447 		return NULL;
1448 
1449 	ssp = &pdata->ssp;
1450 
1451 	ssp->phys_base = res->start;
1452 	ssp->mmio_base = devm_ioremap_resource(&pdev->dev, res);
1453 	if (IS_ERR(ssp->mmio_base))
1454 		return NULL;
1455 
1456 	if (pcidev_id) {
1457 		pdata->tx_param = pdev->dev.parent;
1458 		pdata->rx_param = pdev->dev.parent;
1459 		pdata->dma_filter = pxa2xx_spi_idma_filter;
1460 	}
1461 
1462 	ssp->clk = devm_clk_get(&pdev->dev, NULL);
1463 	ssp->irq = platform_get_irq(pdev, 0);
1464 	ssp->type = type;
1465 	ssp->pdev = pdev;
1466 	ssp->port_id = pxa2xx_spi_get_port_id(adev);
1467 
1468 	pdata->num_chipselect = 1;
1469 	pdata->enable_dma = true;
1470 
1471 	return pdata;
1472 }
1473 
1474 #else /* !CONFIG_PCI */
1475 static inline struct pxa2xx_spi_master *
1476 pxa2xx_spi_init_pdata(struct platform_device *pdev)
1477 {
1478 	return NULL;
1479 }
1480 #endif
1481 
1482 static int pxa2xx_spi_fw_translate_cs(struct spi_master *master, unsigned cs)
1483 {
1484 	struct driver_data *drv_data = spi_master_get_devdata(master);
1485 
1486 	if (has_acpi_companion(&drv_data->pdev->dev)) {
1487 		switch (drv_data->ssp_type) {
1488 		/*
1489 		 * For Atoms the ACPI DeviceSelection used by the Windows
1490 		 * driver starts from 1 instead of 0 so translate it here
1491 		 * to match what Linux expects.
1492 		 */
1493 		case LPSS_BYT_SSP:
1494 		case LPSS_BSW_SSP:
1495 			return cs - 1;
1496 
1497 		default:
1498 			break;
1499 		}
1500 	}
1501 
1502 	return cs;
1503 }
1504 
1505 static int pxa2xx_spi_probe(struct platform_device *pdev)
1506 {
1507 	struct device *dev = &pdev->dev;
1508 	struct pxa2xx_spi_master *platform_info;
1509 	struct spi_master *master;
1510 	struct driver_data *drv_data;
1511 	struct ssp_device *ssp;
1512 	const struct lpss_config *config;
1513 	int status;
1514 	u32 tmp;
1515 
1516 	platform_info = dev_get_platdata(dev);
1517 	if (!platform_info) {
1518 		platform_info = pxa2xx_spi_init_pdata(pdev);
1519 		if (!platform_info) {
1520 			dev_err(&pdev->dev, "missing platform data\n");
1521 			return -ENODEV;
1522 		}
1523 	}
1524 
1525 	ssp = pxa_ssp_request(pdev->id, pdev->name);
1526 	if (!ssp)
1527 		ssp = &platform_info->ssp;
1528 
1529 	if (!ssp->mmio_base) {
1530 		dev_err(&pdev->dev, "failed to get ssp\n");
1531 		return -ENODEV;
1532 	}
1533 
1534 	master = spi_alloc_master(dev, sizeof(struct driver_data));
1535 	if (!master) {
1536 		dev_err(&pdev->dev, "cannot alloc spi_master\n");
1537 		pxa_ssp_free(ssp);
1538 		return -ENOMEM;
1539 	}
1540 	drv_data = spi_master_get_devdata(master);
1541 	drv_data->master = master;
1542 	drv_data->master_info = platform_info;
1543 	drv_data->pdev = pdev;
1544 	drv_data->ssp = ssp;
1545 
1546 	master->dev.parent = &pdev->dev;
1547 	master->dev.of_node = pdev->dev.of_node;
1548 	/* the spi->mode bits understood by this driver: */
1549 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
1550 
1551 	master->bus_num = ssp->port_id;
1552 	master->dma_alignment = DMA_ALIGNMENT;
1553 	master->cleanup = cleanup;
1554 	master->setup = setup;
1555 	master->transfer_one_message = pxa2xx_spi_transfer_one_message;
1556 	master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer;
1557 	master->fw_translate_cs = pxa2xx_spi_fw_translate_cs;
1558 	master->auto_runtime_pm = true;
1559 
1560 	drv_data->ssp_type = ssp->type;
1561 
1562 	drv_data->ioaddr = ssp->mmio_base;
1563 	drv_data->ssdr_physical = ssp->phys_base + SSDR;
1564 	if (pxa25x_ssp_comp(drv_data)) {
1565 		switch (drv_data->ssp_type) {
1566 		case QUARK_X1000_SSP:
1567 			master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1568 			break;
1569 		default:
1570 			master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
1571 			break;
1572 		}
1573 
1574 		drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
1575 		drv_data->dma_cr1 = 0;
1576 		drv_data->clear_sr = SSSR_ROR;
1577 		drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
1578 	} else {
1579 		master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1580 		drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
1581 		drv_data->dma_cr1 = DEFAULT_DMA_CR1;
1582 		drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
1583 		drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
1584 	}
1585 
1586 	status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev),
1587 			drv_data);
1588 	if (status < 0) {
1589 		dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
1590 		goto out_error_master_alloc;
1591 	}
1592 
1593 	/* Setup DMA if requested */
1594 	if (platform_info->enable_dma) {
1595 		status = pxa2xx_spi_dma_setup(drv_data);
1596 		if (status) {
1597 			dev_dbg(dev, "no DMA channels available, using PIO\n");
1598 			platform_info->enable_dma = false;
1599 		}
1600 	}
1601 
1602 	/* Enable SOC clock */
1603 	clk_prepare_enable(ssp->clk);
1604 
1605 	master->max_speed_hz = clk_get_rate(ssp->clk);
1606 
1607 	/* Load default SSP configuration */
1608 	pxa2xx_spi_write(drv_data, SSCR0, 0);
1609 	switch (drv_data->ssp_type) {
1610 	case QUARK_X1000_SSP:
1611 		tmp = QUARK_X1000_SSCR1_RxTresh(RX_THRESH_QUARK_X1000_DFLT)
1612 		      | QUARK_X1000_SSCR1_TxTresh(TX_THRESH_QUARK_X1000_DFLT);
1613 		pxa2xx_spi_write(drv_data, SSCR1, tmp);
1614 
1615 		/* using the Motorola SPI protocol and use 8 bit frame */
1616 		pxa2xx_spi_write(drv_data, SSCR0,
1617 				 QUARK_X1000_SSCR0_Motorola
1618 				 | QUARK_X1000_SSCR0_DataSize(8));
1619 		break;
1620 	default:
1621 		tmp = SSCR1_RxTresh(RX_THRESH_DFLT) |
1622 		      SSCR1_TxTresh(TX_THRESH_DFLT);
1623 		pxa2xx_spi_write(drv_data, SSCR1, tmp);
1624 		tmp = SSCR0_SCR(2) | SSCR0_Motorola | SSCR0_DataSize(8);
1625 		pxa2xx_spi_write(drv_data, SSCR0, tmp);
1626 		break;
1627 	}
1628 
1629 	if (!pxa25x_ssp_comp(drv_data))
1630 		pxa2xx_spi_write(drv_data, SSTO, 0);
1631 
1632 	if (!is_quark_x1000_ssp(drv_data))
1633 		pxa2xx_spi_write(drv_data, SSPSP, 0);
1634 
1635 	if (is_lpss_ssp(drv_data)) {
1636 		lpss_ssp_setup(drv_data);
1637 		config = lpss_get_config(drv_data);
1638 		if (config->reg_capabilities >= 0) {
1639 			tmp = __lpss_ssp_read_priv(drv_data,
1640 						   config->reg_capabilities);
1641 			tmp &= LPSS_CAPS_CS_EN_MASK;
1642 			tmp >>= LPSS_CAPS_CS_EN_SHIFT;
1643 			platform_info->num_chipselect = ffz(tmp);
1644 		} else if (config->cs_num) {
1645 			platform_info->num_chipselect = config->cs_num;
1646 		}
1647 	}
1648 	master->num_chipselect = platform_info->num_chipselect;
1649 
1650 	tasklet_init(&drv_data->pump_transfers, pump_transfers,
1651 		     (unsigned long)drv_data);
1652 
1653 	pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
1654 	pm_runtime_use_autosuspend(&pdev->dev);
1655 	pm_runtime_set_active(&pdev->dev);
1656 	pm_runtime_enable(&pdev->dev);
1657 
1658 	/* Register with the SPI framework */
1659 	platform_set_drvdata(pdev, drv_data);
1660 	status = devm_spi_register_master(&pdev->dev, master);
1661 	if (status != 0) {
1662 		dev_err(&pdev->dev, "problem registering spi master\n");
1663 		goto out_error_clock_enabled;
1664 	}
1665 
1666 	return status;
1667 
1668 out_error_clock_enabled:
1669 	clk_disable_unprepare(ssp->clk);
1670 	pxa2xx_spi_dma_release(drv_data);
1671 	free_irq(ssp->irq, drv_data);
1672 
1673 out_error_master_alloc:
1674 	spi_master_put(master);
1675 	pxa_ssp_free(ssp);
1676 	return status;
1677 }
1678 
1679 static int pxa2xx_spi_remove(struct platform_device *pdev)
1680 {
1681 	struct driver_data *drv_data = platform_get_drvdata(pdev);
1682 	struct ssp_device *ssp;
1683 
1684 	if (!drv_data)
1685 		return 0;
1686 	ssp = drv_data->ssp;
1687 
1688 	pm_runtime_get_sync(&pdev->dev);
1689 
1690 	/* Disable the SSP at the peripheral and SOC level */
1691 	pxa2xx_spi_write(drv_data, SSCR0, 0);
1692 	clk_disable_unprepare(ssp->clk);
1693 
1694 	/* Release DMA */
1695 	if (drv_data->master_info->enable_dma)
1696 		pxa2xx_spi_dma_release(drv_data);
1697 
1698 	pm_runtime_put_noidle(&pdev->dev);
1699 	pm_runtime_disable(&pdev->dev);
1700 
1701 	/* Release IRQ */
1702 	free_irq(ssp->irq, drv_data);
1703 
1704 	/* Release SSP */
1705 	pxa_ssp_free(ssp);
1706 
1707 	return 0;
1708 }
1709 
1710 static void pxa2xx_spi_shutdown(struct platform_device *pdev)
1711 {
1712 	int status = 0;
1713 
1714 	if ((status = pxa2xx_spi_remove(pdev)) != 0)
1715 		dev_err(&pdev->dev, "shutdown failed with %d\n", status);
1716 }
1717 
1718 #ifdef CONFIG_PM_SLEEP
1719 static int pxa2xx_spi_suspend(struct device *dev)
1720 {
1721 	struct driver_data *drv_data = dev_get_drvdata(dev);
1722 	struct ssp_device *ssp = drv_data->ssp;
1723 	int status = 0;
1724 
1725 	status = spi_master_suspend(drv_data->master);
1726 	if (status != 0)
1727 		return status;
1728 	pxa2xx_spi_write(drv_data, SSCR0, 0);
1729 
1730 	if (!pm_runtime_suspended(dev))
1731 		clk_disable_unprepare(ssp->clk);
1732 
1733 	return 0;
1734 }
1735 
1736 static int pxa2xx_spi_resume(struct device *dev)
1737 {
1738 	struct driver_data *drv_data = dev_get_drvdata(dev);
1739 	struct ssp_device *ssp = drv_data->ssp;
1740 	int status = 0;
1741 
1742 	/* Enable the SSP clock */
1743 	if (!pm_runtime_suspended(dev))
1744 		clk_prepare_enable(ssp->clk);
1745 
1746 	/* Restore LPSS private register bits */
1747 	if (is_lpss_ssp(drv_data))
1748 		lpss_ssp_setup(drv_data);
1749 
1750 	/* Start the queue running */
1751 	status = spi_master_resume(drv_data->master);
1752 	if (status != 0) {
1753 		dev_err(dev, "problem starting queue (%d)\n", status);
1754 		return status;
1755 	}
1756 
1757 	return 0;
1758 }
1759 #endif
1760 
1761 #ifdef CONFIG_PM
1762 static int pxa2xx_spi_runtime_suspend(struct device *dev)
1763 {
1764 	struct driver_data *drv_data = dev_get_drvdata(dev);
1765 
1766 	clk_disable_unprepare(drv_data->ssp->clk);
1767 	return 0;
1768 }
1769 
1770 static int pxa2xx_spi_runtime_resume(struct device *dev)
1771 {
1772 	struct driver_data *drv_data = dev_get_drvdata(dev);
1773 
1774 	clk_prepare_enable(drv_data->ssp->clk);
1775 	return 0;
1776 }
1777 #endif
1778 
1779 static const struct dev_pm_ops pxa2xx_spi_pm_ops = {
1780 	SET_SYSTEM_SLEEP_PM_OPS(pxa2xx_spi_suspend, pxa2xx_spi_resume)
1781 	SET_RUNTIME_PM_OPS(pxa2xx_spi_runtime_suspend,
1782 			   pxa2xx_spi_runtime_resume, NULL)
1783 };
1784 
1785 static struct platform_driver driver = {
1786 	.driver = {
1787 		.name	= "pxa2xx-spi",
1788 		.pm	= &pxa2xx_spi_pm_ops,
1789 		.acpi_match_table = ACPI_PTR(pxa2xx_spi_acpi_match),
1790 	},
1791 	.probe = pxa2xx_spi_probe,
1792 	.remove = pxa2xx_spi_remove,
1793 	.shutdown = pxa2xx_spi_shutdown,
1794 };
1795 
1796 static int __init pxa2xx_spi_init(void)
1797 {
1798 	return platform_driver_register(&driver);
1799 }
1800 subsys_initcall(pxa2xx_spi_init);
1801 
1802 static void __exit pxa2xx_spi_exit(void)
1803 {
1804 	platform_driver_unregister(&driver);
1805 }
1806 module_exit(pxa2xx_spi_exit);
1807