2 * au1550_spi.c - au1550 psc spi controller driver
3 * may work also with au1200, au1210, au1250
4 * will not work on au1000, au1100 and au1500 (no full spi controller there)
6 * Copyright (c) 2006 ATRON electronic GmbH
7 * Author: Jan Nikitenko <jan.nikitenko@gmail.com>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/errno.h>
27 #include <linux/device.h>
28 #include <linux/platform_device.h>
29 #include <linux/resource.h>
30 #include <linux/spi/spi.h>
31 #include <linux/spi/spi_bitbang.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/completion.h>
34 #include <asm/mach-au1x00/au1000.h>
35 #include <asm/mach-au1x00/au1xxx_psc.h>
36 #include <asm/mach-au1x00/au1xxx_dbdma.h>
38 #include <asm/mach-au1x00/au1550_spi.h>
40 static unsigned usedma = 1;
41 module_param(usedma, uint, 0644);
44 #define AU1550_SPI_DEBUG_LOOPBACK
48 #define AU1550_SPI_DBDMA_DESCRIPTORS 1
49 #define AU1550_SPI_DMA_RXTMP_MINSIZE 2048U
52 struct spi_bitbang bitbang;
54 volatile psc_spi_t __iomem *regs;
65 void (*rx_word)(struct au1550_spi *hw);
66 void (*tx_word)(struct au1550_spi *hw);
67 int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
68 irqreturn_t (*irq_callback)(struct au1550_spi *hw);
70 struct completion master_done;
79 unsigned dma_rx_tmpbuf_size;
80 u32 dma_rx_tmpbuf_addr;
82 struct spi_master *master;
84 struct au1550_spi_info *pdata;
85 struct resource *ioarea;
89 /* we use an 8-bit memory device for dma transfers to/from spi fifo */
90 static dbdev_tab_t au1550_spi_mem_dbdev =
92 .dev_id = DBDMA_MEM_CHAN,
93 .dev_flags = DEV_FLAGS_ANYUSE|DEV_FLAGS_SYNC,
96 .dev_physaddr = 0x00000000,
101 static int ddma_memid; /* id to above mem dma device */
103 static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw);
107 * compute BRG and DIV bits to setup spi clock based on main input clock rate
108 * that was specified in platform data structure
109 * according to au1550 datasheet:
110 * psc_tempclk = psc_mainclk / (2 << DIV)
111 * spiclk = psc_tempclk / (2 * (BRG + 1))
112 * BRG valid range is 4..63
113 * DIV valid range is 0..3
115 static u32 au1550_spi_baudcfg(struct au1550_spi *hw, unsigned speed_hz)
117 u32 mainclk_hz = hw->pdata->mainclk_hz;
120 for (div = 0; div < 4; div++) {
121 brg = mainclk_hz / speed_hz / (4 << div);
122 /* now we have BRG+1 in brg, so count with that */
124 brg = (4 + 1); /* speed_hz too big */
125 break; /* set lowest brg (div is == 0) */
128 break; /* we have valid brg and div */
131 div = 3; /* speed_hz too small */
132 brg = (63 + 1); /* set highest brg and div */
135 return PSC_SPICFG_SET_BAUD(brg) | PSC_SPICFG_SET_DIV(div);
138 static inline void au1550_spi_mask_ack_all(struct au1550_spi *hw)
140 hw->regs->psc_spimsk =
141 PSC_SPIMSK_MM | PSC_SPIMSK_RR | PSC_SPIMSK_RO
142 | PSC_SPIMSK_RU | PSC_SPIMSK_TR | PSC_SPIMSK_TO
143 | PSC_SPIMSK_TU | PSC_SPIMSK_SD | PSC_SPIMSK_MD;
146 hw->regs->psc_spievent =
147 PSC_SPIEVNT_MM | PSC_SPIEVNT_RR | PSC_SPIEVNT_RO
148 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TR | PSC_SPIEVNT_TO
149 | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD | PSC_SPIEVNT_MD;
153 static void au1550_spi_reset_fifos(struct au1550_spi *hw)
157 hw->regs->psc_spipcr = PSC_SPIPCR_RC | PSC_SPIPCR_TC;
160 pcr = hw->regs->psc_spipcr;
166 * dma transfers are used for the most common spi word size of 8-bits
167 * we cannot easily change already set up dma channels' width, so if we wanted
168 * dma support for more than 8-bit words (up to 24 bits), we would need to
169 * setup dma channels from scratch on each spi transfer, based on bits_per_word
170 * instead we have pre set up 8 bit dma channels supporting spi 4 to 8 bits
171 * transfers, and 9 to 24 bits spi transfers will be done in pio irq based mode
172 * callbacks to handle dma or pio are set up in au1550_spi_bits_handlers_set()
174 static void au1550_spi_chipsel(struct spi_device *spi, int value)
176 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
177 unsigned cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
181 case BITBANG_CS_INACTIVE:
182 if (hw->pdata->deactivate_cs)
183 hw->pdata->deactivate_cs(hw->pdata, spi->chip_select,
187 case BITBANG_CS_ACTIVE:
188 au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
190 cfg = hw->regs->psc_spicfg;
192 hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
195 if (spi->mode & SPI_CPOL)
196 cfg |= PSC_SPICFG_BI;
198 cfg &= ~PSC_SPICFG_BI;
199 if (spi->mode & SPI_CPHA)
200 cfg &= ~PSC_SPICFG_CDE;
202 cfg |= PSC_SPICFG_CDE;
204 if (spi->mode & SPI_LSB_FIRST)
205 cfg |= PSC_SPICFG_MLF;
207 cfg &= ~PSC_SPICFG_MLF;
209 if (hw->usedma && spi->bits_per_word <= 8)
210 cfg &= ~PSC_SPICFG_DD_DISABLE;
212 cfg |= PSC_SPICFG_DD_DISABLE;
213 cfg = PSC_SPICFG_CLR_LEN(cfg);
214 cfg |= PSC_SPICFG_SET_LEN(spi->bits_per_word);
216 cfg = PSC_SPICFG_CLR_BAUD(cfg);
217 cfg &= ~PSC_SPICFG_SET_DIV(3);
218 cfg |= au1550_spi_baudcfg(hw, spi->max_speed_hz);
220 hw->regs->psc_spicfg = cfg | PSC_SPICFG_DE_ENABLE;
223 stat = hw->regs->psc_spistat;
225 } while ((stat & PSC_SPISTAT_DR) == 0);
227 if (hw->pdata->activate_cs)
228 hw->pdata->activate_cs(hw->pdata, spi->chip_select,
234 static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t)
236 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
240 bpw = t ? t->bits_per_word : spi->bits_per_word;
241 hz = t ? t->speed_hz : spi->max_speed_hz;
243 if (bpw < 4 || bpw > 24) {
244 dev_err(&spi->dev, "setupxfer: invalid bits_per_word=%d\n",
248 if (hz > spi->max_speed_hz || hz > hw->freq_max || hz < hw->freq_min) {
249 dev_err(&spi->dev, "setupxfer: clock rate=%d out of range\n",
254 au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
256 cfg = hw->regs->psc_spicfg;
258 hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
261 if (hw->usedma && bpw <= 8)
262 cfg &= ~PSC_SPICFG_DD_DISABLE;
264 cfg |= PSC_SPICFG_DD_DISABLE;
265 cfg = PSC_SPICFG_CLR_LEN(cfg);
266 cfg |= PSC_SPICFG_SET_LEN(bpw);
268 cfg = PSC_SPICFG_CLR_BAUD(cfg);
269 cfg &= ~PSC_SPICFG_SET_DIV(3);
270 cfg |= au1550_spi_baudcfg(hw, hz);
272 hw->regs->psc_spicfg = cfg;
275 if (cfg & PSC_SPICFG_DE_ENABLE) {
277 stat = hw->regs->psc_spistat;
279 } while ((stat & PSC_SPISTAT_DR) == 0);
282 au1550_spi_reset_fifos(hw);
283 au1550_spi_mask_ack_all(hw);
287 /* the spi->mode bits understood by this driver: */
288 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
290 static int au1550_spi_setup(struct spi_device *spi)
292 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
294 if (spi->bits_per_word == 0)
295 spi->bits_per_word = 8;
296 if (spi->bits_per_word < 4 || spi->bits_per_word > 24) {
297 dev_err(&spi->dev, "setup: invalid bits_per_word=%d\n",
302 if (spi->mode & ~MODEBITS) {
303 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
304 spi->mode & ~MODEBITS);
308 if (spi->max_speed_hz == 0)
309 spi->max_speed_hz = hw->freq_max;
310 if (spi->max_speed_hz > hw->freq_max
311 || spi->max_speed_hz < hw->freq_min)
314 * NOTE: cannot change speed and other hw settings immediately,
315 * otherwise sharing of spi bus is not possible,
316 * so do not call setupxfer(spi, NULL) here
322 * for dma spi transfers, we have to setup rx channel, otherwise there is
323 * no reliable way how to recognize that spi transfer is done
324 * dma complete callbacks are called before real spi transfer is finished
325 * and if only tx dma channel is set up (and rx fifo overflow event masked)
326 * spi master done event irq is not generated unless rx fifo is empty (emptied)
327 * so we need rx tmp buffer to use for rx dma if user does not provide one
329 static int au1550_spi_dma_rxtmp_alloc(struct au1550_spi *hw, unsigned size)
331 hw->dma_rx_tmpbuf = kmalloc(size, GFP_KERNEL);
332 if (!hw->dma_rx_tmpbuf)
334 hw->dma_rx_tmpbuf_size = size;
335 hw->dma_rx_tmpbuf_addr = dma_map_single(hw->dev, hw->dma_rx_tmpbuf,
336 size, DMA_FROM_DEVICE);
337 if (dma_mapping_error(hw->dev, hw->dma_rx_tmpbuf_addr)) {
338 kfree(hw->dma_rx_tmpbuf);
339 hw->dma_rx_tmpbuf = 0;
340 hw->dma_rx_tmpbuf_size = 0;
346 static void au1550_spi_dma_rxtmp_free(struct au1550_spi *hw)
348 dma_unmap_single(hw->dev, hw->dma_rx_tmpbuf_addr,
349 hw->dma_rx_tmpbuf_size, DMA_FROM_DEVICE);
350 kfree(hw->dma_rx_tmpbuf);
351 hw->dma_rx_tmpbuf = 0;
352 hw->dma_rx_tmpbuf_size = 0;
355 static int au1550_spi_dma_txrxb(struct spi_device *spi, struct spi_transfer *t)
357 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
358 dma_addr_t dma_tx_addr;
359 dma_addr_t dma_rx_addr;
368 dma_tx_addr = t->tx_dma;
369 dma_rx_addr = t->rx_dma;
372 * check if buffers are already dma mapped, map them otherwise:
373 * - first map the TX buffer, so cache data gets written to memory
374 * - then map the RX buffer, so that cache entries (with
375 * soon-to-be-stale data) get removed
376 * use rx buffer in place of tx if tx buffer was not provided
377 * use temp rx buffer (preallocated or realloc to fit) for rx dma
380 if (t->tx_dma == 0) { /* if DMA_ADDR_INVALID, map it */
381 dma_tx_addr = dma_map_single(hw->dev,
383 t->len, DMA_TO_DEVICE);
384 if (dma_mapping_error(hw->dev, dma_tx_addr))
385 dev_err(hw->dev, "tx dma map error\n");
390 if (t->rx_dma == 0) { /* if DMA_ADDR_INVALID, map it */
391 dma_rx_addr = dma_map_single(hw->dev,
393 t->len, DMA_FROM_DEVICE);
394 if (dma_mapping_error(hw->dev, dma_rx_addr))
395 dev_err(hw->dev, "rx dma map error\n");
398 if (t->len > hw->dma_rx_tmpbuf_size) {
401 au1550_spi_dma_rxtmp_free(hw);
402 ret = au1550_spi_dma_rxtmp_alloc(hw, max(t->len,
403 AU1550_SPI_DMA_RXTMP_MINSIZE));
407 hw->rx = hw->dma_rx_tmpbuf;
408 dma_rx_addr = hw->dma_rx_tmpbuf_addr;
409 dma_sync_single_for_device(hw->dev, dma_rx_addr,
410 t->len, DMA_FROM_DEVICE);
414 dma_sync_single_for_device(hw->dev, dma_rx_addr,
415 t->len, DMA_BIDIRECTIONAL);
419 /* put buffers on the ring */
420 res = au1xxx_dbdma_put_dest(hw->dma_rx_ch, hw->rx, t->len);
422 dev_err(hw->dev, "rx dma put dest error\n");
424 res = au1xxx_dbdma_put_source(hw->dma_tx_ch, (void *)hw->tx, t->len);
426 dev_err(hw->dev, "tx dma put source error\n");
428 au1xxx_dbdma_start(hw->dma_rx_ch);
429 au1xxx_dbdma_start(hw->dma_tx_ch);
431 /* by default enable nearly all events interrupt */
432 hw->regs->psc_spimsk = PSC_SPIMSK_SD;
435 /* start the transfer */
436 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
439 wait_for_completion(&hw->master_done);
441 au1xxx_dbdma_stop(hw->dma_tx_ch);
442 au1xxx_dbdma_stop(hw->dma_rx_ch);
445 /* using the temporal preallocated and premapped buffer */
446 dma_sync_single_for_cpu(hw->dev, dma_rx_addr, t->len,
449 /* unmap buffers if mapped above */
450 if (t->rx_buf && t->rx_dma == 0 )
451 dma_unmap_single(hw->dev, dma_rx_addr, t->len,
453 if (t->tx_buf && t->tx_dma == 0 )
454 dma_unmap_single(hw->dev, dma_tx_addr, t->len,
457 return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count;
460 static irqreturn_t au1550_spi_dma_irq_callback(struct au1550_spi *hw)
464 stat = hw->regs->psc_spistat;
465 evnt = hw->regs->psc_spievent;
467 if ((stat & PSC_SPISTAT_DI) == 0) {
468 dev_err(hw->dev, "Unexpected IRQ!\n");
472 if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO
473 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO
474 | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD))
477 * due to an spi error we consider transfer as done,
478 * so mask all events until before next transfer start
479 * and stop the possibly running dma immediatelly
481 au1550_spi_mask_ack_all(hw);
482 au1xxx_dbdma_stop(hw->dma_rx_ch);
483 au1xxx_dbdma_stop(hw->dma_tx_ch);
485 /* get number of transfered bytes */
486 hw->rx_count = hw->len - au1xxx_get_dma_residue(hw->dma_rx_ch);
487 hw->tx_count = hw->len - au1xxx_get_dma_residue(hw->dma_tx_ch);
489 au1xxx_dbdma_reset(hw->dma_rx_ch);
490 au1xxx_dbdma_reset(hw->dma_tx_ch);
491 au1550_spi_reset_fifos(hw);
493 if (evnt == PSC_SPIEVNT_RO)
495 "dma transfer: receive FIFO overflow!\n");
498 "dma transfer: unexpected SPI error "
499 "(event=0x%x stat=0x%x)!\n", evnt, stat);
501 complete(&hw->master_done);
505 if ((evnt & PSC_SPIEVNT_MD) != 0) {
506 /* transfer completed successfully */
507 au1550_spi_mask_ack_all(hw);
508 hw->rx_count = hw->len;
509 hw->tx_count = hw->len;
510 complete(&hw->master_done);
516 /* routines to handle different word sizes in pio mode */
517 #define AU1550_SPI_RX_WORD(size, mask) \
518 static void au1550_spi_rx_word_##size(struct au1550_spi *hw) \
520 u32 fifoword = hw->regs->psc_spitxrx & (u32)(mask); \
523 *(u##size *)hw->rx = (u##size)fifoword; \
524 hw->rx += (size) / 8; \
526 hw->rx_count += (size) / 8; \
529 #define AU1550_SPI_TX_WORD(size, mask) \
530 static void au1550_spi_tx_word_##size(struct au1550_spi *hw) \
534 fifoword = *(u##size *)hw->tx & (u32)(mask); \
535 hw->tx += (size) / 8; \
537 hw->tx_count += (size) / 8; \
538 if (hw->tx_count >= hw->len) \
539 fifoword |= PSC_SPITXRX_LC; \
540 hw->regs->psc_spitxrx = fifoword; \
544 AU1550_SPI_RX_WORD(8,0xff)
545 AU1550_SPI_RX_WORD(16,0xffff)
546 AU1550_SPI_RX_WORD(32,0xffffff)
547 AU1550_SPI_TX_WORD(8,0xff)
548 AU1550_SPI_TX_WORD(16,0xffff)
549 AU1550_SPI_TX_WORD(32,0xffffff)
551 static int au1550_spi_pio_txrxb(struct spi_device *spi, struct spi_transfer *t)
554 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
562 /* by default enable nearly all events after filling tx fifo */
563 mask = PSC_SPIMSK_SD;
565 /* fill the transmit FIFO */
566 while (hw->tx_count < hw->len) {
570 if (hw->tx_count >= hw->len) {
571 /* mask tx fifo request interrupt as we are done */
572 mask |= PSC_SPIMSK_TR;
575 stat = hw->regs->psc_spistat;
577 if (stat & PSC_SPISTAT_TF)
581 /* enable event interrupts */
582 hw->regs->psc_spimsk = mask;
585 /* start the transfer */
586 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
589 wait_for_completion(&hw->master_done);
591 return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count;
594 static irqreturn_t au1550_spi_pio_irq_callback(struct au1550_spi *hw)
599 stat = hw->regs->psc_spistat;
600 evnt = hw->regs->psc_spievent;
602 if ((stat & PSC_SPISTAT_DI) == 0) {
603 dev_err(hw->dev, "Unexpected IRQ!\n");
607 if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO
608 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO
612 * due to an error we consider transfer as done,
613 * so mask all events until before next transfer start
615 au1550_spi_mask_ack_all(hw);
616 au1550_spi_reset_fifos(hw);
618 "pio transfer: unexpected SPI error "
619 "(event=0x%x stat=0x%x)!\n", evnt, stat);
620 complete(&hw->master_done);
625 * while there is something to read from rx fifo
626 * or there is a space to write to tx fifo:
630 stat = hw->regs->psc_spistat;
634 * Take care to not let the Rx FIFO overflow.
636 * We only write a byte if we have read one at least. Initially,
637 * the write fifo is full, so we should read from the read fifo
639 * In case we miss a word from the read fifo, we should get a
640 * RO event and should back out.
642 if (!(stat & PSC_SPISTAT_RE) && hw->rx_count < hw->len) {
646 if (!(stat & PSC_SPISTAT_TF) && hw->tx_count < hw->len)
651 hw->regs->psc_spievent = PSC_SPIEVNT_RR | PSC_SPIEVNT_TR;
655 * Restart the SPI transmission in case of a transmit underflow.
656 * This seems to work despite the notes in the Au1550 data book
657 * of Figure 8-4 with flowchart for SPI master operation:
659 * """Note 1: An XFR Error Interrupt occurs, unless masked,
660 * for any of the following events: Tx FIFO Underflow,
661 * Rx FIFO Overflow, or Multiple-master Error
662 * Note 2: In case of a Tx Underflow Error, all zeroes are
665 * By simply restarting the spi transfer on Tx Underflow Error,
666 * we assume that spi transfer was paused instead of zeroes
667 * transmittion mentioned in the Note 2 of Au1550 data book.
669 if (evnt & PSC_SPIEVNT_TU) {
670 hw->regs->psc_spievent = PSC_SPIEVNT_TU | PSC_SPIEVNT_MD;
672 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
676 if (hw->rx_count >= hw->len) {
677 /* transfer completed successfully */
678 au1550_spi_mask_ack_all(hw);
679 complete(&hw->master_done);
684 static int au1550_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
686 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
687 return hw->txrx_bufs(spi, t);
690 static irqreturn_t au1550_spi_irq(int irq, void *dev)
692 struct au1550_spi *hw = dev;
693 return hw->irq_callback(hw);
696 static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw)
700 hw->txrx_bufs = &au1550_spi_dma_txrxb;
701 hw->irq_callback = &au1550_spi_dma_irq_callback;
703 hw->rx_word = &au1550_spi_rx_word_8;
704 hw->tx_word = &au1550_spi_tx_word_8;
705 hw->txrx_bufs = &au1550_spi_pio_txrxb;
706 hw->irq_callback = &au1550_spi_pio_irq_callback;
708 } else if (bpw <= 16) {
709 hw->rx_word = &au1550_spi_rx_word_16;
710 hw->tx_word = &au1550_spi_tx_word_16;
711 hw->txrx_bufs = &au1550_spi_pio_txrxb;
712 hw->irq_callback = &au1550_spi_pio_irq_callback;
714 hw->rx_word = &au1550_spi_rx_word_32;
715 hw->tx_word = &au1550_spi_tx_word_32;
716 hw->txrx_bufs = &au1550_spi_pio_txrxb;
717 hw->irq_callback = &au1550_spi_pio_irq_callback;
721 static void __init au1550_spi_setup_psc_as_spi(struct au1550_spi *hw)
725 /* set up the PSC for SPI mode */
726 hw->regs->psc_ctrl = PSC_CTRL_DISABLE;
728 hw->regs->psc_sel = PSC_SEL_PS_SPIMODE;
731 hw->regs->psc_spicfg = 0;
734 hw->regs->psc_ctrl = PSC_CTRL_ENABLE;
738 stat = hw->regs->psc_spistat;
740 } while ((stat & PSC_SPISTAT_SR) == 0);
743 cfg = hw->usedma ? 0 : PSC_SPICFG_DD_DISABLE;
744 cfg |= PSC_SPICFG_SET_LEN(8);
745 cfg |= PSC_SPICFG_RT_FIFO8 | PSC_SPICFG_TT_FIFO8;
746 /* use minimal allowed brg and div values as initial setting: */
747 cfg |= PSC_SPICFG_SET_BAUD(4) | PSC_SPICFG_SET_DIV(0);
749 #ifdef AU1550_SPI_DEBUG_LOOPBACK
750 cfg |= PSC_SPICFG_LB;
753 hw->regs->psc_spicfg = cfg;
756 au1550_spi_mask_ack_all(hw);
758 hw->regs->psc_spicfg |= PSC_SPICFG_DE_ENABLE;
762 stat = hw->regs->psc_spistat;
764 } while ((stat & PSC_SPISTAT_DR) == 0);
766 au1550_spi_reset_fifos(hw);
770 static int __init au1550_spi_probe(struct platform_device *pdev)
772 struct au1550_spi *hw;
773 struct spi_master *master;
777 master = spi_alloc_master(&pdev->dev, sizeof(struct au1550_spi));
778 if (master == NULL) {
779 dev_err(&pdev->dev, "No memory for spi_master\n");
784 hw = spi_master_get_devdata(master);
786 hw->master = spi_master_get(master);
787 hw->pdata = pdev->dev.platform_data;
788 hw->dev = &pdev->dev;
790 if (hw->pdata == NULL) {
791 dev_err(&pdev->dev, "No platform data supplied\n");
796 r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
798 dev_err(&pdev->dev, "no IRQ\n");
805 r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
807 hw->dma_tx_id = r->start;
808 r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
810 hw->dma_rx_id = r->start;
811 if (usedma && ddma_memid) {
812 if (pdev->dev.dma_mask == NULL)
813 dev_warn(&pdev->dev, "no dma mask\n");
820 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
822 dev_err(&pdev->dev, "no mmio resource\n");
827 hw->ioarea = request_mem_region(r->start, sizeof(psc_spi_t),
830 dev_err(&pdev->dev, "Cannot reserve iomem region\n");
835 hw->regs = (psc_spi_t __iomem *)ioremap(r->start, sizeof(psc_spi_t));
837 dev_err(&pdev->dev, "cannot ioremap\n");
842 platform_set_drvdata(pdev, hw);
844 init_completion(&hw->master_done);
846 hw->bitbang.master = hw->master;
847 hw->bitbang.setup_transfer = au1550_spi_setupxfer;
848 hw->bitbang.chipselect = au1550_spi_chipsel;
849 hw->bitbang.master->setup = au1550_spi_setup;
850 hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs;
853 hw->dma_tx_ch = au1xxx_dbdma_chan_alloc(ddma_memid,
854 hw->dma_tx_id, NULL, (void *)hw);
855 if (hw->dma_tx_ch == 0) {
857 "Cannot allocate tx dma channel\n");
861 au1xxx_dbdma_set_devwidth(hw->dma_tx_ch, 8);
862 if (au1xxx_dbdma_ring_alloc(hw->dma_tx_ch,
863 AU1550_SPI_DBDMA_DESCRIPTORS) == 0) {
865 "Cannot allocate tx dma descriptors\n");
867 goto err_no_txdma_descr;
871 hw->dma_rx_ch = au1xxx_dbdma_chan_alloc(hw->dma_rx_id,
872 ddma_memid, NULL, (void *)hw);
873 if (hw->dma_rx_ch == 0) {
875 "Cannot allocate rx dma channel\n");
879 au1xxx_dbdma_set_devwidth(hw->dma_rx_ch, 8);
880 if (au1xxx_dbdma_ring_alloc(hw->dma_rx_ch,
881 AU1550_SPI_DBDMA_DESCRIPTORS) == 0) {
883 "Cannot allocate rx dma descriptors\n");
885 goto err_no_rxdma_descr;
888 err = au1550_spi_dma_rxtmp_alloc(hw,
889 AU1550_SPI_DMA_RXTMP_MINSIZE);
892 "Cannot allocate initial rx dma tmp buffer\n");
893 goto err_dma_rxtmp_alloc;
897 au1550_spi_bits_handlers_set(hw, 8);
899 err = request_irq(hw->irq, au1550_spi_irq, 0, pdev->name, hw);
901 dev_err(&pdev->dev, "Cannot claim IRQ\n");
905 master->bus_num = pdev->id;
906 master->num_chipselect = hw->pdata->num_chipselect;
909 * precompute valid range for spi freq - from au1550 datasheet:
910 * psc_tempclk = psc_mainclk / (2 << DIV)
911 * spiclk = psc_tempclk / (2 * (BRG + 1))
912 * BRG valid range is 4..63
913 * DIV valid range is 0..3
914 * round the min and max frequencies to values that would still
915 * produce valid brg and div
918 int min_div = (2 << 0) * (2 * (4 + 1));
919 int max_div = (2 << 3) * (2 * (63 + 1));
920 hw->freq_max = hw->pdata->mainclk_hz / min_div;
921 hw->freq_min = hw->pdata->mainclk_hz / (max_div + 1) + 1;
924 au1550_spi_setup_psc_as_spi(hw);
926 err = spi_bitbang_start(&hw->bitbang);
928 dev_err(&pdev->dev, "Failed to register SPI master\n");
933 "spi master registered: bus_num=%d num_chipselect=%d\n",
934 master->bus_num, master->num_chipselect);
939 free_irq(hw->irq, hw);
942 au1550_spi_dma_rxtmp_free(hw);
947 au1xxx_dbdma_chan_free(hw->dma_rx_ch);
952 au1xxx_dbdma_chan_free(hw->dma_tx_ch);
955 iounmap((void __iomem *)hw->regs);
958 release_resource(hw->ioarea);
963 spi_master_put(hw->master);
969 static int __exit au1550_spi_remove(struct platform_device *pdev)
971 struct au1550_spi *hw = platform_get_drvdata(pdev);
973 dev_info(&pdev->dev, "spi master remove: bus_num=%d\n",
974 hw->master->bus_num);
976 spi_bitbang_stop(&hw->bitbang);
977 free_irq(hw->irq, hw);
978 iounmap((void __iomem *)hw->regs);
979 release_resource(hw->ioarea);
983 au1550_spi_dma_rxtmp_free(hw);
984 au1xxx_dbdma_chan_free(hw->dma_rx_ch);
985 au1xxx_dbdma_chan_free(hw->dma_tx_ch);
988 platform_set_drvdata(pdev, NULL);
990 spi_master_put(hw->master);
994 /* work with hotplug and coldplug */
995 MODULE_ALIAS("platform:au1550-spi");
997 static struct platform_driver au1550_spi_drv = {
998 .remove = __exit_p(au1550_spi_remove),
1000 .name = "au1550-spi",
1001 .owner = THIS_MODULE,
1005 static int __init au1550_spi_init(void)
1008 * create memory device with 8 bits dev_devwidth
1009 * needed for proper byte ordering to spi fifo
1012 ddma_memid = au1xxx_ddma_add_device(&au1550_spi_mem_dbdev);
1014 printk(KERN_ERR "au1550-spi: cannot add memory"
1017 return platform_driver_probe(&au1550_spi_drv, au1550_spi_probe);
1019 module_init(au1550_spi_init);
1021 static void __exit au1550_spi_exit(void)
1023 if (usedma && ddma_memid)
1024 au1xxx_ddma_del_device(ddma_memid);
1025 platform_driver_unregister(&au1550_spi_drv);
1027 module_exit(au1550_spi_exit);
1029 MODULE_DESCRIPTION("Au1550 PSC SPI Driver");
1030 MODULE_AUTHOR("Jan Nikitenko <jan.nikitenko@gmail.com>");
1031 MODULE_LICENSE("GPL");