Merge tag 'gpio-for-v3.11-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
[linux-2.6.git] / drivers / spi / spi-pxa2xx.c
blobf440dcee852b582a2eb3369c5effd94c83fa3737
1 /*
2 * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
3 * Copyright (C) 2013, Intel Corporation
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.
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.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include <linux/init.h>
21 #include <linux/module.h>
22 #include <linux/device.h>
23 #include <linux/ioport.h>
24 #include <linux/errno.h>
25 #include <linux/err.h>
26 #include <linux/interrupt.h>
27 #include <linux/platform_device.h>
28 #include <linux/spi/pxa2xx_spi.h>
29 #include <linux/spi/spi.h>
30 #include <linux/workqueue.h>
31 #include <linux/delay.h>
32 #include <linux/gpio.h>
33 #include <linux/slab.h>
34 #include <linux/clk.h>
35 #include <linux/pm_runtime.h>
36 #include <linux/acpi.h>
38 #include <asm/io.h>
39 #include <asm/irq.h>
40 #include <asm/delay.h>
42 #include "spi-pxa2xx.h"
44 MODULE_AUTHOR("Stephen Street");
45 MODULE_DESCRIPTION("PXA2xx SSP SPI Controller");
46 MODULE_LICENSE("GPL");
47 MODULE_ALIAS("platform:pxa2xx-spi");
49 #define MAX_BUSES 3
51 #define TIMOUT_DFLT 1000
54 * for testing SSCR1 changes that require SSP restart, basically
55 * everything except the service and interrupt enables, the pxa270 developer
56 * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this
57 * list, but the PXA255 dev man says all bits without really meaning the
58 * service and interrupt enables
60 #define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \
61 | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \
62 | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \
63 | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \
64 | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
65 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
67 #define LPSS_RX_THRESH_DFLT 64
68 #define LPSS_TX_LOTHRESH_DFLT 160
69 #define LPSS_TX_HITHRESH_DFLT 224
71 /* Offset from drv_data->lpss_base */
72 #define SSP_REG 0x0c
73 #define SPI_CS_CONTROL 0x18
74 #define SPI_CS_CONTROL_SW_MODE BIT(0)
75 #define SPI_CS_CONTROL_CS_HIGH BIT(1)
77 static bool is_lpss_ssp(const struct driver_data *drv_data)
79 return drv_data->ssp_type == LPSS_SSP;
83 * Read and write LPSS SSP private registers. Caller must first check that
84 * is_lpss_ssp() returns true before these can be called.
86 static u32 __lpss_ssp_read_priv(struct driver_data *drv_data, unsigned offset)
88 WARN_ON(!drv_data->lpss_base);
89 return readl(drv_data->lpss_base + offset);
92 static void __lpss_ssp_write_priv(struct driver_data *drv_data,
93 unsigned offset, u32 value)
95 WARN_ON(!drv_data->lpss_base);
96 writel(value, drv_data->lpss_base + offset);
100 * lpss_ssp_setup - perform LPSS SSP specific setup
101 * @drv_data: pointer to the driver private data
103 * Perform LPSS SSP specific setup. This function must be called first if
104 * one is going to use LPSS SSP private registers.
106 static void lpss_ssp_setup(struct driver_data *drv_data)
108 unsigned offset = 0x400;
109 u32 value, orig;
111 if (!is_lpss_ssp(drv_data))
112 return;
115 * Perform auto-detection of the LPSS SSP private registers. They
116 * can be either at 1k or 2k offset from the base address.
118 orig = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
120 value = orig | SPI_CS_CONTROL_SW_MODE;
121 writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL);
122 value = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
123 if (value != (orig | SPI_CS_CONTROL_SW_MODE)) {
124 offset = 0x800;
125 goto detection_done;
128 value &= ~SPI_CS_CONTROL_SW_MODE;
129 writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL);
130 value = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
131 if (value != orig) {
132 offset = 0x800;
133 goto detection_done;
136 detection_done:
137 /* Now set the LPSS base */
138 drv_data->lpss_base = drv_data->ioaddr + offset;
140 /* Enable software chip select control */
141 value = SPI_CS_CONTROL_SW_MODE | SPI_CS_CONTROL_CS_HIGH;
142 __lpss_ssp_write_priv(drv_data, SPI_CS_CONTROL, value);
144 /* Enable multiblock DMA transfers */
145 if (drv_data->master_info->enable_dma)
146 __lpss_ssp_write_priv(drv_data, SSP_REG, 1);
149 static void lpss_ssp_cs_control(struct driver_data *drv_data, bool enable)
151 u32 value;
153 if (!is_lpss_ssp(drv_data))
154 return;
156 value = __lpss_ssp_read_priv(drv_data, SPI_CS_CONTROL);
157 if (enable)
158 value &= ~SPI_CS_CONTROL_CS_HIGH;
159 else
160 value |= SPI_CS_CONTROL_CS_HIGH;
161 __lpss_ssp_write_priv(drv_data, SPI_CS_CONTROL, value);
164 static void cs_assert(struct driver_data *drv_data)
166 struct chip_data *chip = drv_data->cur_chip;
168 if (drv_data->ssp_type == CE4100_SSP) {
169 write_SSSR(drv_data->cur_chip->frm, drv_data->ioaddr);
170 return;
173 if (chip->cs_control) {
174 chip->cs_control(PXA2XX_CS_ASSERT);
175 return;
178 if (gpio_is_valid(chip->gpio_cs)) {
179 gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
180 return;
183 lpss_ssp_cs_control(drv_data, true);
186 static void cs_deassert(struct driver_data *drv_data)
188 struct chip_data *chip = drv_data->cur_chip;
190 if (drv_data->ssp_type == CE4100_SSP)
191 return;
193 if (chip->cs_control) {
194 chip->cs_control(PXA2XX_CS_DEASSERT);
195 return;
198 if (gpio_is_valid(chip->gpio_cs)) {
199 gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
200 return;
203 lpss_ssp_cs_control(drv_data, false);
206 int pxa2xx_spi_flush(struct driver_data *drv_data)
208 unsigned long limit = loops_per_jiffy << 1;
210 void __iomem *reg = drv_data->ioaddr;
212 do {
213 while (read_SSSR(reg) & SSSR_RNE) {
214 read_SSDR(reg);
216 } while ((read_SSSR(reg) & SSSR_BSY) && --limit);
217 write_SSSR_CS(drv_data, SSSR_ROR);
219 return limit;
222 static int null_writer(struct driver_data *drv_data)
224 void __iomem *reg = drv_data->ioaddr;
225 u8 n_bytes = drv_data->n_bytes;
227 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
228 || (drv_data->tx == drv_data->tx_end))
229 return 0;
231 write_SSDR(0, reg);
232 drv_data->tx += n_bytes;
234 return 1;
237 static int null_reader(struct driver_data *drv_data)
239 void __iomem *reg = drv_data->ioaddr;
240 u8 n_bytes = drv_data->n_bytes;
242 while ((read_SSSR(reg) & SSSR_RNE)
243 && (drv_data->rx < drv_data->rx_end)) {
244 read_SSDR(reg);
245 drv_data->rx += n_bytes;
248 return drv_data->rx == drv_data->rx_end;
251 static int u8_writer(struct driver_data *drv_data)
253 void __iomem *reg = drv_data->ioaddr;
255 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
256 || (drv_data->tx == drv_data->tx_end))
257 return 0;
259 write_SSDR(*(u8 *)(drv_data->tx), reg);
260 ++drv_data->tx;
262 return 1;
265 static int u8_reader(struct driver_data *drv_data)
267 void __iomem *reg = drv_data->ioaddr;
269 while ((read_SSSR(reg) & SSSR_RNE)
270 && (drv_data->rx < drv_data->rx_end)) {
271 *(u8 *)(drv_data->rx) = read_SSDR(reg);
272 ++drv_data->rx;
275 return drv_data->rx == drv_data->rx_end;
278 static int u16_writer(struct driver_data *drv_data)
280 void __iomem *reg = drv_data->ioaddr;
282 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
283 || (drv_data->tx == drv_data->tx_end))
284 return 0;
286 write_SSDR(*(u16 *)(drv_data->tx), reg);
287 drv_data->tx += 2;
289 return 1;
292 static int u16_reader(struct driver_data *drv_data)
294 void __iomem *reg = drv_data->ioaddr;
296 while ((read_SSSR(reg) & SSSR_RNE)
297 && (drv_data->rx < drv_data->rx_end)) {
298 *(u16 *)(drv_data->rx) = read_SSDR(reg);
299 drv_data->rx += 2;
302 return drv_data->rx == drv_data->rx_end;
305 static int u32_writer(struct driver_data *drv_data)
307 void __iomem *reg = drv_data->ioaddr;
309 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK)
310 || (drv_data->tx == drv_data->tx_end))
311 return 0;
313 write_SSDR(*(u32 *)(drv_data->tx), reg);
314 drv_data->tx += 4;
316 return 1;
319 static int u32_reader(struct driver_data *drv_data)
321 void __iomem *reg = drv_data->ioaddr;
323 while ((read_SSSR(reg) & SSSR_RNE)
324 && (drv_data->rx < drv_data->rx_end)) {
325 *(u32 *)(drv_data->rx) = read_SSDR(reg);
326 drv_data->rx += 4;
329 return drv_data->rx == drv_data->rx_end;
332 void *pxa2xx_spi_next_transfer(struct driver_data *drv_data)
334 struct spi_message *msg = drv_data->cur_msg;
335 struct spi_transfer *trans = drv_data->cur_transfer;
337 /* Move to next transfer */
338 if (trans->transfer_list.next != &msg->transfers) {
339 drv_data->cur_transfer =
340 list_entry(trans->transfer_list.next,
341 struct spi_transfer,
342 transfer_list);
343 return RUNNING_STATE;
344 } else
345 return DONE_STATE;
348 /* caller already set message->status; dma and pio irqs are blocked */
349 static void giveback(struct driver_data *drv_data)
351 struct spi_transfer* last_transfer;
352 struct spi_message *msg;
354 msg = drv_data->cur_msg;
355 drv_data->cur_msg = NULL;
356 drv_data->cur_transfer = NULL;
358 last_transfer = list_entry(msg->transfers.prev,
359 struct spi_transfer,
360 transfer_list);
362 /* Delay if requested before any change in chip select */
363 if (last_transfer->delay_usecs)
364 udelay(last_transfer->delay_usecs);
366 /* Drop chip select UNLESS cs_change is true or we are returning
367 * a message with an error, or next message is for another chip
369 if (!last_transfer->cs_change)
370 cs_deassert(drv_data);
371 else {
372 struct spi_message *next_msg;
374 /* Holding of cs was hinted, but we need to make sure
375 * the next message is for the same chip. Don't waste
376 * time with the following tests unless this was hinted.
378 * We cannot postpone this until pump_messages, because
379 * after calling msg->complete (below) the driver that
380 * sent the current message could be unloaded, which
381 * could invalidate the cs_control() callback...
384 /* get a pointer to the next message, if any */
385 next_msg = spi_get_next_queued_message(drv_data->master);
387 /* see if the next and current messages point
388 * to the same chip
390 if (next_msg && next_msg->spi != msg->spi)
391 next_msg = NULL;
392 if (!next_msg || msg->state == ERROR_STATE)
393 cs_deassert(drv_data);
396 spi_finalize_current_message(drv_data->master);
397 drv_data->cur_chip = NULL;
400 static void reset_sccr1(struct driver_data *drv_data)
402 void __iomem *reg = drv_data->ioaddr;
403 struct chip_data *chip = drv_data->cur_chip;
404 u32 sccr1_reg;
406 sccr1_reg = read_SSCR1(reg) & ~drv_data->int_cr1;
407 sccr1_reg &= ~SSCR1_RFT;
408 sccr1_reg |= chip->threshold;
409 write_SSCR1(sccr1_reg, reg);
412 static void int_error_stop(struct driver_data *drv_data, const char* msg)
414 void __iomem *reg = drv_data->ioaddr;
416 /* Stop and reset SSP */
417 write_SSSR_CS(drv_data, drv_data->clear_sr);
418 reset_sccr1(drv_data);
419 if (!pxa25x_ssp_comp(drv_data))
420 write_SSTO(0, reg);
421 pxa2xx_spi_flush(drv_data);
422 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
424 dev_err(&drv_data->pdev->dev, "%s\n", msg);
426 drv_data->cur_msg->state = ERROR_STATE;
427 tasklet_schedule(&drv_data->pump_transfers);
430 static void int_transfer_complete(struct driver_data *drv_data)
432 void __iomem *reg = drv_data->ioaddr;
434 /* Stop SSP */
435 write_SSSR_CS(drv_data, drv_data->clear_sr);
436 reset_sccr1(drv_data);
437 if (!pxa25x_ssp_comp(drv_data))
438 write_SSTO(0, reg);
440 /* Update total byte transferred return count actual bytes read */
441 drv_data->cur_msg->actual_length += drv_data->len -
442 (drv_data->rx_end - drv_data->rx);
444 /* Transfer delays and chip select release are
445 * handled in pump_transfers or giveback
448 /* Move to next transfer */
449 drv_data->cur_msg->state = pxa2xx_spi_next_transfer(drv_data);
451 /* Schedule transfer tasklet */
452 tasklet_schedule(&drv_data->pump_transfers);
455 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
457 void __iomem *reg = drv_data->ioaddr;
459 u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
460 drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
462 u32 irq_status = read_SSSR(reg) & irq_mask;
464 if (irq_status & SSSR_ROR) {
465 int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
466 return IRQ_HANDLED;
469 if (irq_status & SSSR_TINT) {
470 write_SSSR(SSSR_TINT, reg);
471 if (drv_data->read(drv_data)) {
472 int_transfer_complete(drv_data);
473 return IRQ_HANDLED;
477 /* Drain rx fifo, Fill tx fifo and prevent overruns */
478 do {
479 if (drv_data->read(drv_data)) {
480 int_transfer_complete(drv_data);
481 return IRQ_HANDLED;
483 } while (drv_data->write(drv_data));
485 if (drv_data->read(drv_data)) {
486 int_transfer_complete(drv_data);
487 return IRQ_HANDLED;
490 if (drv_data->tx == drv_data->tx_end) {
491 u32 bytes_left;
492 u32 sccr1_reg;
494 sccr1_reg = read_SSCR1(reg);
495 sccr1_reg &= ~SSCR1_TIE;
498 * PXA25x_SSP has no timeout, set up rx threshould for the
499 * remaining RX bytes.
501 if (pxa25x_ssp_comp(drv_data)) {
503 sccr1_reg &= ~SSCR1_RFT;
505 bytes_left = drv_data->rx_end - drv_data->rx;
506 switch (drv_data->n_bytes) {
507 case 4:
508 bytes_left >>= 1;
509 case 2:
510 bytes_left >>= 1;
513 if (bytes_left > RX_THRESH_DFLT)
514 bytes_left = RX_THRESH_DFLT;
516 sccr1_reg |= SSCR1_RxTresh(bytes_left);
518 write_SSCR1(sccr1_reg, reg);
521 /* We did something */
522 return IRQ_HANDLED;
525 static irqreturn_t ssp_int(int irq, void *dev_id)
527 struct driver_data *drv_data = dev_id;
528 void __iomem *reg = drv_data->ioaddr;
529 u32 sccr1_reg;
530 u32 mask = drv_data->mask_sr;
531 u32 status;
534 * The IRQ might be shared with other peripherals so we must first
535 * check that are we RPM suspended or not. If we are we assume that
536 * the IRQ was not for us (we shouldn't be RPM suspended when the
537 * interrupt is enabled).
539 if (pm_runtime_suspended(&drv_data->pdev->dev))
540 return IRQ_NONE;
542 sccr1_reg = read_SSCR1(reg);
543 status = read_SSSR(reg);
545 /* Ignore possible writes if we don't need to write */
546 if (!(sccr1_reg & SSCR1_TIE))
547 mask &= ~SSSR_TFS;
549 if (!(status & mask))
550 return IRQ_NONE;
552 if (!drv_data->cur_msg) {
554 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
555 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
556 if (!pxa25x_ssp_comp(drv_data))
557 write_SSTO(0, reg);
558 write_SSSR_CS(drv_data, drv_data->clear_sr);
560 dev_err(&drv_data->pdev->dev, "bad message state "
561 "in interrupt handler\n");
563 /* Never fail */
564 return IRQ_HANDLED;
567 return drv_data->transfer_handler(drv_data);
570 static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
572 unsigned long ssp_clk = drv_data->max_clk_rate;
573 const struct ssp_device *ssp = drv_data->ssp;
575 rate = min_t(int, ssp_clk, rate);
577 if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP)
578 return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8;
579 else
580 return ((ssp_clk / rate - 1) & 0xfff) << 8;
583 static void pump_transfers(unsigned long data)
585 struct driver_data *drv_data = (struct driver_data *)data;
586 struct spi_message *message = NULL;
587 struct spi_transfer *transfer = NULL;
588 struct spi_transfer *previous = NULL;
589 struct chip_data *chip = NULL;
590 void __iomem *reg = drv_data->ioaddr;
591 u32 clk_div = 0;
592 u8 bits = 0;
593 u32 speed = 0;
594 u32 cr0;
595 u32 cr1;
596 u32 dma_thresh = drv_data->cur_chip->dma_threshold;
597 u32 dma_burst = drv_data->cur_chip->dma_burst_size;
599 /* Get current state information */
600 message = drv_data->cur_msg;
601 transfer = drv_data->cur_transfer;
602 chip = drv_data->cur_chip;
604 /* Handle for abort */
605 if (message->state == ERROR_STATE) {
606 message->status = -EIO;
607 giveback(drv_data);
608 return;
611 /* Handle end of message */
612 if (message->state == DONE_STATE) {
613 message->status = 0;
614 giveback(drv_data);
615 return;
618 /* Delay if requested at end of transfer before CS change */
619 if (message->state == RUNNING_STATE) {
620 previous = list_entry(transfer->transfer_list.prev,
621 struct spi_transfer,
622 transfer_list);
623 if (previous->delay_usecs)
624 udelay(previous->delay_usecs);
626 /* Drop chip select only if cs_change is requested */
627 if (previous->cs_change)
628 cs_deassert(drv_data);
631 /* Check if we can DMA this transfer */
632 if (!pxa2xx_spi_dma_is_possible(transfer->len) && chip->enable_dma) {
634 /* reject already-mapped transfers; PIO won't always work */
635 if (message->is_dma_mapped
636 || transfer->rx_dma || transfer->tx_dma) {
637 dev_err(&drv_data->pdev->dev,
638 "pump_transfers: mapped transfer length "
639 "of %u is greater than %d\n",
640 transfer->len, MAX_DMA_LEN);
641 message->status = -EINVAL;
642 giveback(drv_data);
643 return;
646 /* warn ... we force this to PIO mode */
647 if (printk_ratelimit())
648 dev_warn(&message->spi->dev, "pump_transfers: "
649 "DMA disabled for transfer length %ld "
650 "greater than %d\n",
651 (long)drv_data->len, MAX_DMA_LEN);
654 /* Setup the transfer state based on the type of transfer */
655 if (pxa2xx_spi_flush(drv_data) == 0) {
656 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
657 message->status = -EIO;
658 giveback(drv_data);
659 return;
661 drv_data->n_bytes = chip->n_bytes;
662 drv_data->tx = (void *)transfer->tx_buf;
663 drv_data->tx_end = drv_data->tx + transfer->len;
664 drv_data->rx = transfer->rx_buf;
665 drv_data->rx_end = drv_data->rx + transfer->len;
666 drv_data->rx_dma = transfer->rx_dma;
667 drv_data->tx_dma = transfer->tx_dma;
668 drv_data->len = transfer->len;
669 drv_data->write = drv_data->tx ? chip->write : null_writer;
670 drv_data->read = drv_data->rx ? chip->read : null_reader;
672 /* Change speed and bit per word on a per transfer */
673 cr0 = chip->cr0;
674 if (transfer->speed_hz || transfer->bits_per_word) {
676 bits = chip->bits_per_word;
677 speed = chip->speed_hz;
679 if (transfer->speed_hz)
680 speed = transfer->speed_hz;
682 if (transfer->bits_per_word)
683 bits = transfer->bits_per_word;
685 clk_div = ssp_get_clk_div(drv_data, speed);
687 if (bits <= 8) {
688 drv_data->n_bytes = 1;
689 drv_data->read = drv_data->read != null_reader ?
690 u8_reader : null_reader;
691 drv_data->write = drv_data->write != null_writer ?
692 u8_writer : null_writer;
693 } else if (bits <= 16) {
694 drv_data->n_bytes = 2;
695 drv_data->read = drv_data->read != null_reader ?
696 u16_reader : null_reader;
697 drv_data->write = drv_data->write != null_writer ?
698 u16_writer : null_writer;
699 } else if (bits <= 32) {
700 drv_data->n_bytes = 4;
701 drv_data->read = drv_data->read != null_reader ?
702 u32_reader : null_reader;
703 drv_data->write = drv_data->write != null_writer ?
704 u32_writer : null_writer;
706 /* if bits/word is changed in dma mode, then must check the
707 * thresholds and burst also */
708 if (chip->enable_dma) {
709 if (pxa2xx_spi_set_dma_burst_and_threshold(chip,
710 message->spi,
711 bits, &dma_burst,
712 &dma_thresh))
713 if (printk_ratelimit())
714 dev_warn(&message->spi->dev,
715 "pump_transfers: "
716 "DMA burst size reduced to "
717 "match bits_per_word\n");
720 cr0 = clk_div
721 | SSCR0_Motorola
722 | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
723 | SSCR0_SSE
724 | (bits > 16 ? SSCR0_EDSS : 0);
727 message->state = RUNNING_STATE;
729 drv_data->dma_mapped = 0;
730 if (pxa2xx_spi_dma_is_possible(drv_data->len))
731 drv_data->dma_mapped = pxa2xx_spi_map_dma_buffers(drv_data);
732 if (drv_data->dma_mapped) {
734 /* Ensure we have the correct interrupt handler */
735 drv_data->transfer_handler = pxa2xx_spi_dma_transfer;
737 pxa2xx_spi_dma_prepare(drv_data, dma_burst);
739 /* Clear status and start DMA engine */
740 cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1;
741 write_SSSR(drv_data->clear_sr, reg);
743 pxa2xx_spi_dma_start(drv_data);
744 } else {
745 /* Ensure we have the correct interrupt handler */
746 drv_data->transfer_handler = interrupt_transfer;
748 /* Clear status */
749 cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1;
750 write_SSSR_CS(drv_data, drv_data->clear_sr);
753 if (is_lpss_ssp(drv_data)) {
754 if ((read_SSIRF(reg) & 0xff) != chip->lpss_rx_threshold)
755 write_SSIRF(chip->lpss_rx_threshold, reg);
756 if ((read_SSITF(reg) & 0xffff) != chip->lpss_tx_threshold)
757 write_SSITF(chip->lpss_tx_threshold, reg);
760 /* see if we need to reload the config registers */
761 if ((read_SSCR0(reg) != cr0)
762 || (read_SSCR1(reg) & SSCR1_CHANGE_MASK) !=
763 (cr1 & SSCR1_CHANGE_MASK)) {
765 /* stop the SSP, and update the other bits */
766 write_SSCR0(cr0 & ~SSCR0_SSE, reg);
767 if (!pxa25x_ssp_comp(drv_data))
768 write_SSTO(chip->timeout, reg);
769 /* first set CR1 without interrupt and service enables */
770 write_SSCR1(cr1 & SSCR1_CHANGE_MASK, reg);
771 /* restart the SSP */
772 write_SSCR0(cr0, reg);
774 } else {
775 if (!pxa25x_ssp_comp(drv_data))
776 write_SSTO(chip->timeout, reg);
779 cs_assert(drv_data);
781 /* after chip select, release the data by enabling service
782 * requests and interrupts, without changing any mode bits */
783 write_SSCR1(cr1, reg);
786 static int pxa2xx_spi_transfer_one_message(struct spi_master *master,
787 struct spi_message *msg)
789 struct driver_data *drv_data = spi_master_get_devdata(master);
791 drv_data->cur_msg = msg;
792 /* Initial message state*/
793 drv_data->cur_msg->state = START_STATE;
794 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
795 struct spi_transfer,
796 transfer_list);
798 /* prepare to setup the SSP, in pump_transfers, using the per
799 * chip configuration */
800 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
802 /* Mark as busy and launch transfers */
803 tasklet_schedule(&drv_data->pump_transfers);
804 return 0;
807 static int pxa2xx_spi_prepare_transfer(struct spi_master *master)
809 struct driver_data *drv_data = spi_master_get_devdata(master);
811 pm_runtime_get_sync(&drv_data->pdev->dev);
812 return 0;
815 static int pxa2xx_spi_unprepare_transfer(struct spi_master *master)
817 struct driver_data *drv_data = spi_master_get_devdata(master);
819 /* Disable the SSP now */
820 write_SSCR0(read_SSCR0(drv_data->ioaddr) & ~SSCR0_SSE,
821 drv_data->ioaddr);
823 pm_runtime_mark_last_busy(&drv_data->pdev->dev);
824 pm_runtime_put_autosuspend(&drv_data->pdev->dev);
825 return 0;
828 static int setup_cs(struct spi_device *spi, struct chip_data *chip,
829 struct pxa2xx_spi_chip *chip_info)
831 int err = 0;
833 if (chip == NULL || chip_info == NULL)
834 return 0;
836 /* NOTE: setup() can be called multiple times, possibly with
837 * different chip_info, release previously requested GPIO
839 if (gpio_is_valid(chip->gpio_cs))
840 gpio_free(chip->gpio_cs);
842 /* If (*cs_control) is provided, ignore GPIO chip select */
843 if (chip_info->cs_control) {
844 chip->cs_control = chip_info->cs_control;
845 return 0;
848 if (gpio_is_valid(chip_info->gpio_cs)) {
849 err = gpio_request(chip_info->gpio_cs, "SPI_CS");
850 if (err) {
851 dev_err(&spi->dev, "failed to request chip select "
852 "GPIO%d\n", chip_info->gpio_cs);
853 return err;
856 chip->gpio_cs = chip_info->gpio_cs;
857 chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
859 err = gpio_direction_output(chip->gpio_cs,
860 !chip->gpio_cs_inverted);
863 return err;
866 static int setup(struct spi_device *spi)
868 struct pxa2xx_spi_chip *chip_info = NULL;
869 struct chip_data *chip;
870 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
871 unsigned int clk_div;
872 uint tx_thres, tx_hi_thres, rx_thres;
874 if (is_lpss_ssp(drv_data)) {
875 tx_thres = LPSS_TX_LOTHRESH_DFLT;
876 tx_hi_thres = LPSS_TX_HITHRESH_DFLT;
877 rx_thres = LPSS_RX_THRESH_DFLT;
878 } else {
879 tx_thres = TX_THRESH_DFLT;
880 tx_hi_thres = 0;
881 rx_thres = RX_THRESH_DFLT;
884 /* Only alloc on first setup */
885 chip = spi_get_ctldata(spi);
886 if (!chip) {
887 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
888 if (!chip) {
889 dev_err(&spi->dev,
890 "failed setup: can't allocate chip data\n");
891 return -ENOMEM;
894 if (drv_data->ssp_type == CE4100_SSP) {
895 if (spi->chip_select > 4) {
896 dev_err(&spi->dev, "failed setup: "
897 "cs number must not be > 4.\n");
898 kfree(chip);
899 return -EINVAL;
902 chip->frm = spi->chip_select;
903 } else
904 chip->gpio_cs = -1;
905 chip->enable_dma = 0;
906 chip->timeout = TIMOUT_DFLT;
909 /* protocol drivers may change the chip settings, so...
910 * if chip_info exists, use it */
911 chip_info = spi->controller_data;
913 /* chip_info isn't always needed */
914 chip->cr1 = 0;
915 if (chip_info) {
916 if (chip_info->timeout)
917 chip->timeout = chip_info->timeout;
918 if (chip_info->tx_threshold)
919 tx_thres = chip_info->tx_threshold;
920 if (chip_info->tx_hi_threshold)
921 tx_hi_thres = chip_info->tx_hi_threshold;
922 if (chip_info->rx_threshold)
923 rx_thres = chip_info->rx_threshold;
924 chip->enable_dma = drv_data->master_info->enable_dma;
925 chip->dma_threshold = 0;
926 if (chip_info->enable_loopback)
927 chip->cr1 = SSCR1_LBM;
928 } else if (ACPI_HANDLE(&spi->dev)) {
930 * Slave devices enumerated from ACPI namespace don't
931 * usually have chip_info but we still might want to use
932 * DMA with them.
934 chip->enable_dma = drv_data->master_info->enable_dma;
937 chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
938 (SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
940 chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);
941 chip->lpss_tx_threshold = SSITF_TxLoThresh(tx_thres)
942 | SSITF_TxHiThresh(tx_hi_thres);
944 /* set dma burst and threshold outside of chip_info path so that if
945 * chip_info goes away after setting chip->enable_dma, the
946 * burst and threshold can still respond to changes in bits_per_word */
947 if (chip->enable_dma) {
948 /* set up legal burst and threshold for dma */
949 if (pxa2xx_spi_set_dma_burst_and_threshold(chip, spi,
950 spi->bits_per_word,
951 &chip->dma_burst_size,
952 &chip->dma_threshold)) {
953 dev_warn(&spi->dev, "in setup: DMA burst size reduced "
954 "to match bits_per_word\n");
958 clk_div = ssp_get_clk_div(drv_data, spi->max_speed_hz);
959 chip->speed_hz = spi->max_speed_hz;
961 chip->cr0 = clk_div
962 | SSCR0_Motorola
963 | SSCR0_DataSize(spi->bits_per_word > 16 ?
964 spi->bits_per_word - 16 : spi->bits_per_word)
965 | SSCR0_SSE
966 | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
967 chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
968 chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
969 | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
971 if (spi->mode & SPI_LOOP)
972 chip->cr1 |= SSCR1_LBM;
974 /* NOTE: PXA25x_SSP _could_ use external clocking ... */
975 if (!pxa25x_ssp_comp(drv_data))
976 dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
977 drv_data->max_clk_rate
978 / (1 + ((chip->cr0 & SSCR0_SCR(0xfff)) >> 8)),
979 chip->enable_dma ? "DMA" : "PIO");
980 else
981 dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
982 drv_data->max_clk_rate / 2
983 / (1 + ((chip->cr0 & SSCR0_SCR(0x0ff)) >> 8)),
984 chip->enable_dma ? "DMA" : "PIO");
986 if (spi->bits_per_word <= 8) {
987 chip->n_bytes = 1;
988 chip->read = u8_reader;
989 chip->write = u8_writer;
990 } else if (spi->bits_per_word <= 16) {
991 chip->n_bytes = 2;
992 chip->read = u16_reader;
993 chip->write = u16_writer;
994 } else if (spi->bits_per_word <= 32) {
995 chip->cr0 |= SSCR0_EDSS;
996 chip->n_bytes = 4;
997 chip->read = u32_reader;
998 chip->write = u32_writer;
1000 chip->bits_per_word = spi->bits_per_word;
1002 spi_set_ctldata(spi, chip);
1004 if (drv_data->ssp_type == CE4100_SSP)
1005 return 0;
1007 return setup_cs(spi, chip, chip_info);
1010 static void cleanup(struct spi_device *spi)
1012 struct chip_data *chip = spi_get_ctldata(spi);
1013 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1015 if (!chip)
1016 return;
1018 if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
1019 gpio_free(chip->gpio_cs);
1021 kfree(chip);
1024 #ifdef CONFIG_ACPI
1025 static struct pxa2xx_spi_master *
1026 pxa2xx_spi_acpi_get_pdata(struct platform_device *pdev)
1028 struct pxa2xx_spi_master *pdata;
1029 struct acpi_device *adev;
1030 struct ssp_device *ssp;
1031 struct resource *res;
1032 int devid;
1034 if (!ACPI_HANDLE(&pdev->dev) ||
1035 acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
1036 return NULL;
1038 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
1039 if (!pdata) {
1040 dev_err(&pdev->dev,
1041 "failed to allocate memory for platform data\n");
1042 return NULL;
1045 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1046 if (!res)
1047 return NULL;
1049 ssp = &pdata->ssp;
1051 ssp->phys_base = res->start;
1052 ssp->mmio_base = devm_ioremap_resource(&pdev->dev, res);
1053 if (IS_ERR(ssp->mmio_base))
1054 return NULL;
1056 ssp->clk = devm_clk_get(&pdev->dev, NULL);
1057 ssp->irq = platform_get_irq(pdev, 0);
1058 ssp->type = LPSS_SSP;
1059 ssp->pdev = pdev;
1061 ssp->port_id = -1;
1062 if (adev->pnp.unique_id && !kstrtoint(adev->pnp.unique_id, 0, &devid))
1063 ssp->port_id = devid;
1065 pdata->num_chipselect = 1;
1066 pdata->enable_dma = true;
1068 return pdata;
1071 static struct acpi_device_id pxa2xx_spi_acpi_match[] = {
1072 { "INT33C0", 0 },
1073 { "INT33C1", 0 },
1074 { "80860F0E", 0 },
1075 { },
1077 MODULE_DEVICE_TABLE(acpi, pxa2xx_spi_acpi_match);
1078 #else
1079 static inline struct pxa2xx_spi_master *
1080 pxa2xx_spi_acpi_get_pdata(struct platform_device *pdev)
1082 return NULL;
1084 #endif
1086 static int pxa2xx_spi_probe(struct platform_device *pdev)
1088 struct device *dev = &pdev->dev;
1089 struct pxa2xx_spi_master *platform_info;
1090 struct spi_master *master;
1091 struct driver_data *drv_data;
1092 struct ssp_device *ssp;
1093 int status;
1095 platform_info = dev_get_platdata(dev);
1096 if (!platform_info) {
1097 platform_info = pxa2xx_spi_acpi_get_pdata(pdev);
1098 if (!platform_info) {
1099 dev_err(&pdev->dev, "missing platform data\n");
1100 return -ENODEV;
1104 ssp = pxa_ssp_request(pdev->id, pdev->name);
1105 if (!ssp)
1106 ssp = &platform_info->ssp;
1108 if (!ssp->mmio_base) {
1109 dev_err(&pdev->dev, "failed to get ssp\n");
1110 return -ENODEV;
1113 /* Allocate master with space for drv_data and null dma buffer */
1114 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16);
1115 if (!master) {
1116 dev_err(&pdev->dev, "cannot alloc spi_master\n");
1117 pxa_ssp_free(ssp);
1118 return -ENOMEM;
1120 drv_data = spi_master_get_devdata(master);
1121 drv_data->master = master;
1122 drv_data->master_info = platform_info;
1123 drv_data->pdev = pdev;
1124 drv_data->ssp = ssp;
1126 master->dev.parent = &pdev->dev;
1127 master->dev.of_node = pdev->dev.of_node;
1128 /* the spi->mode bits understood by this driver: */
1129 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
1131 master->bus_num = ssp->port_id;
1132 master->num_chipselect = platform_info->num_chipselect;
1133 master->dma_alignment = DMA_ALIGNMENT;
1134 master->cleanup = cleanup;
1135 master->setup = setup;
1136 master->transfer_one_message = pxa2xx_spi_transfer_one_message;
1137 master->prepare_transfer_hardware = pxa2xx_spi_prepare_transfer;
1138 master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer;
1140 drv_data->ssp_type = ssp->type;
1141 drv_data->null_dma_buf = (u32 *)PTR_ALIGN(&drv_data[1], DMA_ALIGNMENT);
1143 drv_data->ioaddr = ssp->mmio_base;
1144 drv_data->ssdr_physical = ssp->phys_base + SSDR;
1145 if (pxa25x_ssp_comp(drv_data)) {
1146 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
1147 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
1148 drv_data->dma_cr1 = 0;
1149 drv_data->clear_sr = SSSR_ROR;
1150 drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR;
1151 } else {
1152 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1153 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE;
1154 drv_data->dma_cr1 = DEFAULT_DMA_CR1;
1155 drv_data->clear_sr = SSSR_ROR | SSSR_TINT;
1156 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
1159 status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev),
1160 drv_data);
1161 if (status < 0) {
1162 dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
1163 goto out_error_master_alloc;
1166 /* Setup DMA if requested */
1167 drv_data->tx_channel = -1;
1168 drv_data->rx_channel = -1;
1169 if (platform_info->enable_dma) {
1170 status = pxa2xx_spi_dma_setup(drv_data);
1171 if (status) {
1172 dev_dbg(dev, "no DMA channels available, using PIO\n");
1173 platform_info->enable_dma = false;
1177 /* Enable SOC clock */
1178 clk_prepare_enable(ssp->clk);
1180 drv_data->max_clk_rate = clk_get_rate(ssp->clk);
1182 /* Load default SSP configuration */
1183 write_SSCR0(0, drv_data->ioaddr);
1184 write_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) |
1185 SSCR1_TxTresh(TX_THRESH_DFLT),
1186 drv_data->ioaddr);
1187 write_SSCR0(SSCR0_SCR(2)
1188 | SSCR0_Motorola
1189 | SSCR0_DataSize(8),
1190 drv_data->ioaddr);
1191 if (!pxa25x_ssp_comp(drv_data))
1192 write_SSTO(0, drv_data->ioaddr);
1193 write_SSPSP(0, drv_data->ioaddr);
1195 lpss_ssp_setup(drv_data);
1197 tasklet_init(&drv_data->pump_transfers, pump_transfers,
1198 (unsigned long)drv_data);
1200 /* Register with the SPI framework */
1201 platform_set_drvdata(pdev, drv_data);
1202 status = spi_register_master(master);
1203 if (status != 0) {
1204 dev_err(&pdev->dev, "problem registering spi master\n");
1205 goto out_error_clock_enabled;
1208 pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
1209 pm_runtime_use_autosuspend(&pdev->dev);
1210 pm_runtime_set_active(&pdev->dev);
1211 pm_runtime_enable(&pdev->dev);
1213 return status;
1215 out_error_clock_enabled:
1216 clk_disable_unprepare(ssp->clk);
1217 pxa2xx_spi_dma_release(drv_data);
1218 free_irq(ssp->irq, drv_data);
1220 out_error_master_alloc:
1221 spi_master_put(master);
1222 pxa_ssp_free(ssp);
1223 return status;
1226 static int pxa2xx_spi_remove(struct platform_device *pdev)
1228 struct driver_data *drv_data = platform_get_drvdata(pdev);
1229 struct ssp_device *ssp;
1231 if (!drv_data)
1232 return 0;
1233 ssp = drv_data->ssp;
1235 pm_runtime_get_sync(&pdev->dev);
1237 /* Disable the SSP at the peripheral and SOC level */
1238 write_SSCR0(0, drv_data->ioaddr);
1239 clk_disable_unprepare(ssp->clk);
1241 /* Release DMA */
1242 if (drv_data->master_info->enable_dma)
1243 pxa2xx_spi_dma_release(drv_data);
1245 pm_runtime_put_noidle(&pdev->dev);
1246 pm_runtime_disable(&pdev->dev);
1248 /* Release IRQ */
1249 free_irq(ssp->irq, drv_data);
1251 /* Release SSP */
1252 pxa_ssp_free(ssp);
1254 /* Disconnect from the SPI framework */
1255 spi_unregister_master(drv_data->master);
1257 return 0;
1260 static void pxa2xx_spi_shutdown(struct platform_device *pdev)
1262 int status = 0;
1264 if ((status = pxa2xx_spi_remove(pdev)) != 0)
1265 dev_err(&pdev->dev, "shutdown failed with %d\n", status);
1268 #ifdef CONFIG_PM
1269 static int pxa2xx_spi_suspend(struct device *dev)
1271 struct driver_data *drv_data = dev_get_drvdata(dev);
1272 struct ssp_device *ssp = drv_data->ssp;
1273 int status = 0;
1275 status = spi_master_suspend(drv_data->master);
1276 if (status != 0)
1277 return status;
1278 write_SSCR0(0, drv_data->ioaddr);
1279 clk_disable_unprepare(ssp->clk);
1281 return 0;
1284 static int pxa2xx_spi_resume(struct device *dev)
1286 struct driver_data *drv_data = dev_get_drvdata(dev);
1287 struct ssp_device *ssp = drv_data->ssp;
1288 int status = 0;
1290 pxa2xx_spi_dma_resume(drv_data);
1292 /* Enable the SSP clock */
1293 clk_prepare_enable(ssp->clk);
1295 /* Start the queue running */
1296 status = spi_master_resume(drv_data->master);
1297 if (status != 0) {
1298 dev_err(dev, "problem starting queue (%d)\n", status);
1299 return status;
1302 return 0;
1304 #endif
1306 #ifdef CONFIG_PM_RUNTIME
1307 static int pxa2xx_spi_runtime_suspend(struct device *dev)
1309 struct driver_data *drv_data = dev_get_drvdata(dev);
1311 clk_disable_unprepare(drv_data->ssp->clk);
1312 return 0;
1315 static int pxa2xx_spi_runtime_resume(struct device *dev)
1317 struct driver_data *drv_data = dev_get_drvdata(dev);
1319 clk_prepare_enable(drv_data->ssp->clk);
1320 return 0;
1322 #endif
1324 static const struct dev_pm_ops pxa2xx_spi_pm_ops = {
1325 SET_SYSTEM_SLEEP_PM_OPS(pxa2xx_spi_suspend, pxa2xx_spi_resume)
1326 SET_RUNTIME_PM_OPS(pxa2xx_spi_runtime_suspend,
1327 pxa2xx_spi_runtime_resume, NULL)
1330 static struct platform_driver driver = {
1331 .driver = {
1332 .name = "pxa2xx-spi",
1333 .owner = THIS_MODULE,
1334 .pm = &pxa2xx_spi_pm_ops,
1335 .acpi_match_table = ACPI_PTR(pxa2xx_spi_acpi_match),
1337 .probe = pxa2xx_spi_probe,
1338 .remove = pxa2xx_spi_remove,
1339 .shutdown = pxa2xx_spi_shutdown,
1342 static int __init pxa2xx_spi_init(void)
1344 return platform_driver_register(&driver);
1346 subsys_initcall(pxa2xx_spi_init);
1348 static void __exit pxa2xx_spi_exit(void)
1350 platform_driver_unregister(&driver);
1352 module_exit(pxa2xx_spi_exit);