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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * au1550 psc spi controller driver
4 * may work also with au1200, au1210, au1250
5 * will not work on au1000, au1100 and au1500 (no full spi controller there)
6 *
7 * Copyright (c) 2006 ATRON electronic GmbH
8 * Author: Jan Nikitenko <jan.nikitenko@gmail.com>
9 */
10
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/slab.h>
14#include <linux/errno.h>
15#include <linux/module.h>
16#include <linux/device.h>
17#include <linux/platform_device.h>
18#include <linux/resource.h>
19#include <linux/spi/spi.h>
20#include <linux/spi/spi_bitbang.h>
21#include <linux/dma-mapping.h>
22#include <linux/completion.h>
23#include <asm/mach-au1x00/au1000.h>
24#include <asm/mach-au1x00/au1xxx_psc.h>
25#include <asm/mach-au1x00/au1xxx_dbdma.h>
26
27#include <asm/mach-au1x00/au1550_spi.h>
28
29static unsigned int usedma = 1;
30module_param(usedma, uint, 0644);
31
32/*
33#define AU1550_SPI_DEBUG_LOOPBACK
34*/
35
36
37#define AU1550_SPI_DBDMA_DESCRIPTORS 1
38#define AU1550_SPI_DMA_RXTMP_MINSIZE 2048U
39
40struct au1550_spi {
41 struct spi_bitbang bitbang;
42
43 volatile psc_spi_t __iomem *regs;
44 int irq;
45
46 unsigned int len;
47 unsigned int tx_count;
48 unsigned int rx_count;
49 const u8 *tx;
50 u8 *rx;
51
52 void (*rx_word)(struct au1550_spi *hw);
53 void (*tx_word)(struct au1550_spi *hw);
54 int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
55 irqreturn_t (*irq_callback)(struct au1550_spi *hw);
56
57 struct completion master_done;
58
59 unsigned int usedma;
60 u32 dma_tx_id;
61 u32 dma_rx_id;
62 u32 dma_tx_ch;
63 u32 dma_rx_ch;
64
65 u8 *dma_rx_tmpbuf;
66 unsigned int dma_rx_tmpbuf_size;
67 u32 dma_rx_tmpbuf_addr;
68
69 struct spi_master *master;
70 struct device *dev;
71 struct au1550_spi_info *pdata;
72 struct resource *ioarea;
73};
74
75
76/* we use an 8-bit memory device for dma transfers to/from spi fifo */
77static dbdev_tab_t au1550_spi_mem_dbdev = {
78 .dev_id = DBDMA_MEM_CHAN,
79 .dev_flags = DEV_FLAGS_ANYUSE|DEV_FLAGS_SYNC,
80 .dev_tsize = 0,
81 .dev_devwidth = 8,
82 .dev_physaddr = 0x00000000,
83 .dev_intlevel = 0,
84 .dev_intpolarity = 0
85};
86
87static int ddma_memid; /* id to above mem dma device */
88
89static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw);
90
91
92/*
93 * compute BRG and DIV bits to setup spi clock based on main input clock rate
94 * that was specified in platform data structure
95 * according to au1550 datasheet:
96 * psc_tempclk = psc_mainclk / (2 << DIV)
97 * spiclk = psc_tempclk / (2 * (BRG + 1))
98 * BRG valid range is 4..63
99 * DIV valid range is 0..3
100 */
101static u32 au1550_spi_baudcfg(struct au1550_spi *hw, unsigned int speed_hz)
102{
103 u32 mainclk_hz = hw->pdata->mainclk_hz;
104 u32 div, brg;
105
106 for (div = 0; div < 4; div++) {
107 brg = mainclk_hz / speed_hz / (4 << div);
108 /* now we have BRG+1 in brg, so count with that */
109 if (brg < (4 + 1)) {
110 brg = (4 + 1); /* speed_hz too big */
111 break; /* set lowest brg (div is == 0) */
112 }
113 if (brg <= (63 + 1))
114 break; /* we have valid brg and div */
115 }
116 if (div == 4) {
117 div = 3; /* speed_hz too small */
118 brg = (63 + 1); /* set highest brg and div */
119 }
120 brg--;
121 return PSC_SPICFG_SET_BAUD(brg) | PSC_SPICFG_SET_DIV(div);
122}
123
124static inline void au1550_spi_mask_ack_all(struct au1550_spi *hw)
125{
126 hw->regs->psc_spimsk =
127 PSC_SPIMSK_MM | PSC_SPIMSK_RR | PSC_SPIMSK_RO
128 | PSC_SPIMSK_RU | PSC_SPIMSK_TR | PSC_SPIMSK_TO
129 | PSC_SPIMSK_TU | PSC_SPIMSK_SD | PSC_SPIMSK_MD;
130 wmb(); /* drain writebuffer */
131
132 hw->regs->psc_spievent =
133 PSC_SPIEVNT_MM | PSC_SPIEVNT_RR | PSC_SPIEVNT_RO
134 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TR | PSC_SPIEVNT_TO
135 | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD | PSC_SPIEVNT_MD;
136 wmb(); /* drain writebuffer */
137}
138
139static void au1550_spi_reset_fifos(struct au1550_spi *hw)
140{
141 u32 pcr;
142
143 hw->regs->psc_spipcr = PSC_SPIPCR_RC | PSC_SPIPCR_TC;
144 wmb(); /* drain writebuffer */
145 do {
146 pcr = hw->regs->psc_spipcr;
147 wmb(); /* drain writebuffer */
148 } while (pcr != 0);
149}
150
151/*
152 * dma transfers are used for the most common spi word size of 8-bits
153 * we cannot easily change already set up dma channels' width, so if we wanted
154 * dma support for more than 8-bit words (up to 24 bits), we would need to
155 * setup dma channels from scratch on each spi transfer, based on bits_per_word
156 * instead we have pre set up 8 bit dma channels supporting spi 4 to 8 bits
157 * transfers, and 9 to 24 bits spi transfers will be done in pio irq based mode
158 * callbacks to handle dma or pio are set up in au1550_spi_bits_handlers_set()
159 */
160static void au1550_spi_chipsel(struct spi_device *spi, int value)
161{
162 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
163 unsigned int cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
164 u32 cfg, stat;
165
166 switch (value) {
167 case BITBANG_CS_INACTIVE:
168 if (hw->pdata->deactivate_cs)
169 hw->pdata->deactivate_cs(hw->pdata, spi->chip_select,
170 cspol);
171 break;
172
173 case BITBANG_CS_ACTIVE:
174 au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
175
176 cfg = hw->regs->psc_spicfg;
177 wmb(); /* drain writebuffer */
178 hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
179 wmb(); /* drain writebuffer */
180
181 if (spi->mode & SPI_CPOL)
182 cfg |= PSC_SPICFG_BI;
183 else
184 cfg &= ~PSC_SPICFG_BI;
185 if (spi->mode & SPI_CPHA)
186 cfg &= ~PSC_SPICFG_CDE;
187 else
188 cfg |= PSC_SPICFG_CDE;
189
190 if (spi->mode & SPI_LSB_FIRST)
191 cfg |= PSC_SPICFG_MLF;
192 else
193 cfg &= ~PSC_SPICFG_MLF;
194
195 if (hw->usedma && spi->bits_per_word <= 8)
196 cfg &= ~PSC_SPICFG_DD_DISABLE;
197 else
198 cfg |= PSC_SPICFG_DD_DISABLE;
199 cfg = PSC_SPICFG_CLR_LEN(cfg);
200 cfg |= PSC_SPICFG_SET_LEN(spi->bits_per_word);
201
202 cfg = PSC_SPICFG_CLR_BAUD(cfg);
203 cfg &= ~PSC_SPICFG_SET_DIV(3);
204 cfg |= au1550_spi_baudcfg(hw, spi->max_speed_hz);
205
206 hw->regs->psc_spicfg = cfg | PSC_SPICFG_DE_ENABLE;
207 wmb(); /* drain writebuffer */
208 do {
209 stat = hw->regs->psc_spistat;
210 wmb(); /* drain writebuffer */
211 } while ((stat & PSC_SPISTAT_DR) == 0);
212
213 if (hw->pdata->activate_cs)
214 hw->pdata->activate_cs(hw->pdata, spi->chip_select,
215 cspol);
216 break;
217 }
218}
219
220static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t)
221{
222 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
223 unsigned int bpw, hz;
224 u32 cfg, stat;
225
226 if (t) {
227 bpw = t->bits_per_word;
228 hz = t->speed_hz;
229 } else {
230 bpw = spi->bits_per_word;
231 hz = spi->max_speed_hz;
232 }
233
234 if (!hz)
235 return -EINVAL;
236
237 au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
238
239 cfg = hw->regs->psc_spicfg;
240 wmb(); /* drain writebuffer */
241 hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
242 wmb(); /* drain writebuffer */
243
244 if (hw->usedma && bpw <= 8)
245 cfg &= ~PSC_SPICFG_DD_DISABLE;
246 else
247 cfg |= PSC_SPICFG_DD_DISABLE;
248 cfg = PSC_SPICFG_CLR_LEN(cfg);
249 cfg |= PSC_SPICFG_SET_LEN(bpw);
250
251 cfg = PSC_SPICFG_CLR_BAUD(cfg);
252 cfg &= ~PSC_SPICFG_SET_DIV(3);
253 cfg |= au1550_spi_baudcfg(hw, hz);
254
255 hw->regs->psc_spicfg = cfg;
256 wmb(); /* drain writebuffer */
257
258 if (cfg & PSC_SPICFG_DE_ENABLE) {
259 do {
260 stat = hw->regs->psc_spistat;
261 wmb(); /* drain writebuffer */
262 } while ((stat & PSC_SPISTAT_DR) == 0);
263 }
264
265 au1550_spi_reset_fifos(hw);
266 au1550_spi_mask_ack_all(hw);
267 return 0;
268}
269
270/*
271 * for dma spi transfers, we have to setup rx channel, otherwise there is
272 * no reliable way how to recognize that spi transfer is done
273 * dma complete callbacks are called before real spi transfer is finished
274 * and if only tx dma channel is set up (and rx fifo overflow event masked)
275 * spi master done event irq is not generated unless rx fifo is empty (emptied)
276 * so we need rx tmp buffer to use for rx dma if user does not provide one
277 */
278static int au1550_spi_dma_rxtmp_alloc(struct au1550_spi *hw, unsigned int size)
279{
280 hw->dma_rx_tmpbuf = kmalloc(size, GFP_KERNEL);
281 if (!hw->dma_rx_tmpbuf)
282 return -ENOMEM;
283 hw->dma_rx_tmpbuf_size = size;
284 hw->dma_rx_tmpbuf_addr = dma_map_single(hw->dev, hw->dma_rx_tmpbuf,
285 size, DMA_FROM_DEVICE);
286 if (dma_mapping_error(hw->dev, hw->dma_rx_tmpbuf_addr)) {
287 kfree(hw->dma_rx_tmpbuf);
288 hw->dma_rx_tmpbuf = 0;
289 hw->dma_rx_tmpbuf_size = 0;
290 return -EFAULT;
291 }
292 return 0;
293}
294
295static void au1550_spi_dma_rxtmp_free(struct au1550_spi *hw)
296{
297 dma_unmap_single(hw->dev, hw->dma_rx_tmpbuf_addr,
298 hw->dma_rx_tmpbuf_size, DMA_FROM_DEVICE);
299 kfree(hw->dma_rx_tmpbuf);
300 hw->dma_rx_tmpbuf = 0;
301 hw->dma_rx_tmpbuf_size = 0;
302}
303
304static int au1550_spi_dma_txrxb(struct spi_device *spi, struct spi_transfer *t)
305{
306 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
307 dma_addr_t dma_tx_addr;
308 dma_addr_t dma_rx_addr;
309 u32 res;
310
311 hw->len = t->len;
312 hw->tx_count = 0;
313 hw->rx_count = 0;
314
315 hw->tx = t->tx_buf;
316 hw->rx = t->rx_buf;
317 dma_tx_addr = t->tx_dma;
318 dma_rx_addr = t->rx_dma;
319
320 /*
321 * check if buffers are already dma mapped, map them otherwise:
322 * - first map the TX buffer, so cache data gets written to memory
323 * - then map the RX buffer, so that cache entries (with
324 * soon-to-be-stale data) get removed
325 * use rx buffer in place of tx if tx buffer was not provided
326 * use temp rx buffer (preallocated or realloc to fit) for rx dma
327 */
328 if (t->tx_buf) {
329 if (t->tx_dma == 0) { /* if DMA_ADDR_INVALID, map it */
330 dma_tx_addr = dma_map_single(hw->dev,
331 (void *)t->tx_buf,
332 t->len, DMA_TO_DEVICE);
333 if (dma_mapping_error(hw->dev, dma_tx_addr))
334 dev_err(hw->dev, "tx dma map error\n");
335 }
336 }
337
338 if (t->rx_buf) {
339 if (t->rx_dma == 0) { /* if DMA_ADDR_INVALID, map it */
340 dma_rx_addr = dma_map_single(hw->dev,
341 (void *)t->rx_buf,
342 t->len, DMA_FROM_DEVICE);
343 if (dma_mapping_error(hw->dev, dma_rx_addr))
344 dev_err(hw->dev, "rx dma map error\n");
345 }
346 } else {
347 if (t->len > hw->dma_rx_tmpbuf_size) {
348 int ret;
349
350 au1550_spi_dma_rxtmp_free(hw);
351 ret = au1550_spi_dma_rxtmp_alloc(hw, max(t->len,
352 AU1550_SPI_DMA_RXTMP_MINSIZE));
353 if (ret < 0)
354 return ret;
355 }
356 hw->rx = hw->dma_rx_tmpbuf;
357 dma_rx_addr = hw->dma_rx_tmpbuf_addr;
358 dma_sync_single_for_device(hw->dev, dma_rx_addr,
359 t->len, DMA_FROM_DEVICE);
360 }
361
362 if (!t->tx_buf) {
363 dma_sync_single_for_device(hw->dev, dma_rx_addr,
364 t->len, DMA_BIDIRECTIONAL);
365 hw->tx = hw->rx;
366 }
367
368 /* put buffers on the ring */
369 res = au1xxx_dbdma_put_dest(hw->dma_rx_ch, virt_to_phys(hw->rx),
370 t->len, DDMA_FLAGS_IE);
371 if (!res)
372 dev_err(hw->dev, "rx dma put dest error\n");
373
374 res = au1xxx_dbdma_put_source(hw->dma_tx_ch, virt_to_phys(hw->tx),
375 t->len, DDMA_FLAGS_IE);
376 if (!res)
377 dev_err(hw->dev, "tx dma put source error\n");
378
379 au1xxx_dbdma_start(hw->dma_rx_ch);
380 au1xxx_dbdma_start(hw->dma_tx_ch);
381
382 /* by default enable nearly all events interrupt */
383 hw->regs->psc_spimsk = PSC_SPIMSK_SD;
384 wmb(); /* drain writebuffer */
385
386 /* start the transfer */
387 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
388 wmb(); /* drain writebuffer */
389
390 wait_for_completion(&hw->master_done);
391
392 au1xxx_dbdma_stop(hw->dma_tx_ch);
393 au1xxx_dbdma_stop(hw->dma_rx_ch);
394
395 if (!t->rx_buf) {
396 /* using the temporal preallocated and premapped buffer */
397 dma_sync_single_for_cpu(hw->dev, dma_rx_addr, t->len,
398 DMA_FROM_DEVICE);
399 }
400 /* unmap buffers if mapped above */
401 if (t->rx_buf && t->rx_dma == 0)
402 dma_unmap_single(hw->dev, dma_rx_addr, t->len,
403 DMA_FROM_DEVICE);
404 if (t->tx_buf && t->tx_dma == 0)
405 dma_unmap_single(hw->dev, dma_tx_addr, t->len,
406 DMA_TO_DEVICE);
407
408 return min(hw->rx_count, hw->tx_count);
409}
410
411static irqreturn_t au1550_spi_dma_irq_callback(struct au1550_spi *hw)
412{
413 u32 stat, evnt;
414
415 stat = hw->regs->psc_spistat;
416 evnt = hw->regs->psc_spievent;
417 wmb(); /* drain writebuffer */
418 if ((stat & PSC_SPISTAT_DI) == 0) {
419 dev_err(hw->dev, "Unexpected IRQ!\n");
420 return IRQ_NONE;
421 }
422
423 if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO
424 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO
425 | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD))
426 != 0) {
427 /*
428 * due to an spi error we consider transfer as done,
429 * so mask all events until before next transfer start
430 * and stop the possibly running dma immediately
431 */
432 au1550_spi_mask_ack_all(hw);
433 au1xxx_dbdma_stop(hw->dma_rx_ch);
434 au1xxx_dbdma_stop(hw->dma_tx_ch);
435
436 /* get number of transferred bytes */
437 hw->rx_count = hw->len - au1xxx_get_dma_residue(hw->dma_rx_ch);
438 hw->tx_count = hw->len - au1xxx_get_dma_residue(hw->dma_tx_ch);
439
440 au1xxx_dbdma_reset(hw->dma_rx_ch);
441 au1xxx_dbdma_reset(hw->dma_tx_ch);
442 au1550_spi_reset_fifos(hw);
443
444 if (evnt == PSC_SPIEVNT_RO)
445 dev_err(hw->dev,
446 "dma transfer: receive FIFO overflow!\n");
447 else
448 dev_err(hw->dev,
449 "dma transfer: unexpected SPI error (event=0x%x stat=0x%x)!\n",
450 evnt, stat);
451
452 complete(&hw->master_done);
453 return IRQ_HANDLED;
454 }
455
456 if ((evnt & PSC_SPIEVNT_MD) != 0) {
457 /* transfer completed successfully */
458 au1550_spi_mask_ack_all(hw);
459 hw->rx_count = hw->len;
460 hw->tx_count = hw->len;
461 complete(&hw->master_done);
462 }
463 return IRQ_HANDLED;
464}
465
466
467/* routines to handle different word sizes in pio mode */
468#define AU1550_SPI_RX_WORD(size, mask) \
469static void au1550_spi_rx_word_##size(struct au1550_spi *hw) \
470{ \
471 u32 fifoword = hw->regs->psc_spitxrx & (u32)(mask); \
472 wmb(); /* drain writebuffer */ \
473 if (hw->rx) { \
474 *(u##size *)hw->rx = (u##size)fifoword; \
475 hw->rx += (size) / 8; \
476 } \
477 hw->rx_count += (size) / 8; \
478}
479
480#define AU1550_SPI_TX_WORD(size, mask) \
481static void au1550_spi_tx_word_##size(struct au1550_spi *hw) \
482{ \
483 u32 fifoword = 0; \
484 if (hw->tx) { \
485 fifoword = *(u##size *)hw->tx & (u32)(mask); \
486 hw->tx += (size) / 8; \
487 } \
488 hw->tx_count += (size) / 8; \
489 if (hw->tx_count >= hw->len) \
490 fifoword |= PSC_SPITXRX_LC; \
491 hw->regs->psc_spitxrx = fifoword; \
492 wmb(); /* drain writebuffer */ \
493}
494
495AU1550_SPI_RX_WORD(8, 0xff)
496AU1550_SPI_RX_WORD(16, 0xffff)
497AU1550_SPI_RX_WORD(32, 0xffffff)
498AU1550_SPI_TX_WORD(8, 0xff)
499AU1550_SPI_TX_WORD(16, 0xffff)
500AU1550_SPI_TX_WORD(32, 0xffffff)
501
502static int au1550_spi_pio_txrxb(struct spi_device *spi, struct spi_transfer *t)
503{
504 u32 stat, mask;
505 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
506
507 hw->tx = t->tx_buf;
508 hw->rx = t->rx_buf;
509 hw->len = t->len;
510 hw->tx_count = 0;
511 hw->rx_count = 0;
512
513 /* by default enable nearly all events after filling tx fifo */
514 mask = PSC_SPIMSK_SD;
515
516 /* fill the transmit FIFO */
517 while (hw->tx_count < hw->len) {
518
519 hw->tx_word(hw);
520
521 if (hw->tx_count >= hw->len) {
522 /* mask tx fifo request interrupt as we are done */
523 mask |= PSC_SPIMSK_TR;
524 }
525
526 stat = hw->regs->psc_spistat;
527 wmb(); /* drain writebuffer */
528 if (stat & PSC_SPISTAT_TF)
529 break;
530 }
531
532 /* enable event interrupts */
533 hw->regs->psc_spimsk = mask;
534 wmb(); /* drain writebuffer */
535
536 /* start the transfer */
537 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
538 wmb(); /* drain writebuffer */
539
540 wait_for_completion(&hw->master_done);
541
542 return min(hw->rx_count, hw->tx_count);
543}
544
545static irqreturn_t au1550_spi_pio_irq_callback(struct au1550_spi *hw)
546{
547 int busy;
548 u32 stat, evnt;
549
550 stat = hw->regs->psc_spistat;
551 evnt = hw->regs->psc_spievent;
552 wmb(); /* drain writebuffer */
553 if ((stat & PSC_SPISTAT_DI) == 0) {
554 dev_err(hw->dev, "Unexpected IRQ!\n");
555 return IRQ_NONE;
556 }
557
558 if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO
559 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO
560 | PSC_SPIEVNT_SD))
561 != 0) {
562 /*
563 * due to an error we consider transfer as done,
564 * so mask all events until before next transfer start
565 */
566 au1550_spi_mask_ack_all(hw);
567 au1550_spi_reset_fifos(hw);
568 dev_err(hw->dev,
569 "pio transfer: unexpected SPI error (event=0x%x stat=0x%x)!\n",
570 evnt, stat);
571 complete(&hw->master_done);
572 return IRQ_HANDLED;
573 }
574
575 /*
576 * while there is something to read from rx fifo
577 * or there is a space to write to tx fifo:
578 */
579 do {
580 busy = 0;
581 stat = hw->regs->psc_spistat;
582 wmb(); /* drain writebuffer */
583
584 /*
585 * Take care to not let the Rx FIFO overflow.
586 *
587 * We only write a byte if we have read one at least. Initially,
588 * the write fifo is full, so we should read from the read fifo
589 * first.
590 * In case we miss a word from the read fifo, we should get a
591 * RO event and should back out.
592 */
593 if (!(stat & PSC_SPISTAT_RE) && hw->rx_count < hw->len) {
594 hw->rx_word(hw);
595 busy = 1;
596
597 if (!(stat & PSC_SPISTAT_TF) && hw->tx_count < hw->len)
598 hw->tx_word(hw);
599 }
600 } while (busy);
601
602 hw->regs->psc_spievent = PSC_SPIEVNT_RR | PSC_SPIEVNT_TR;
603 wmb(); /* drain writebuffer */
604
605 /*
606 * Restart the SPI transmission in case of a transmit underflow.
607 * This seems to work despite the notes in the Au1550 data book
608 * of Figure 8-4 with flowchart for SPI master operation:
609 *
610 * """Note 1: An XFR Error Interrupt occurs, unless masked,
611 * for any of the following events: Tx FIFO Underflow,
612 * Rx FIFO Overflow, or Multiple-master Error
613 * Note 2: In case of a Tx Underflow Error, all zeroes are
614 * transmitted."""
615 *
616 * By simply restarting the spi transfer on Tx Underflow Error,
617 * we assume that spi transfer was paused instead of zeroes
618 * transmittion mentioned in the Note 2 of Au1550 data book.
619 */
620 if (evnt & PSC_SPIEVNT_TU) {
621 hw->regs->psc_spievent = PSC_SPIEVNT_TU | PSC_SPIEVNT_MD;
622 wmb(); /* drain writebuffer */
623 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
624 wmb(); /* drain writebuffer */
625 }
626
627 if (hw->rx_count >= hw->len) {
628 /* transfer completed successfully */
629 au1550_spi_mask_ack_all(hw);
630 complete(&hw->master_done);
631 }
632 return IRQ_HANDLED;
633}
634
635static int au1550_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
636{
637 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
638
639 return hw->txrx_bufs(spi, t);
640}
641
642static irqreturn_t au1550_spi_irq(int irq, void *dev)
643{
644 struct au1550_spi *hw = dev;
645
646 return hw->irq_callback(hw);
647}
648
649static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw)
650{
651 if (bpw <= 8) {
652 if (hw->usedma) {
653 hw->txrx_bufs = &au1550_spi_dma_txrxb;
654 hw->irq_callback = &au1550_spi_dma_irq_callback;
655 } else {
656 hw->rx_word = &au1550_spi_rx_word_8;
657 hw->tx_word = &au1550_spi_tx_word_8;
658 hw->txrx_bufs = &au1550_spi_pio_txrxb;
659 hw->irq_callback = &au1550_spi_pio_irq_callback;
660 }
661 } else if (bpw <= 16) {
662 hw->rx_word = &au1550_spi_rx_word_16;
663 hw->tx_word = &au1550_spi_tx_word_16;
664 hw->txrx_bufs = &au1550_spi_pio_txrxb;
665 hw->irq_callback = &au1550_spi_pio_irq_callback;
666 } else {
667 hw->rx_word = &au1550_spi_rx_word_32;
668 hw->tx_word = &au1550_spi_tx_word_32;
669 hw->txrx_bufs = &au1550_spi_pio_txrxb;
670 hw->irq_callback = &au1550_spi_pio_irq_callback;
671 }
672}
673
674static void au1550_spi_setup_psc_as_spi(struct au1550_spi *hw)
675{
676 u32 stat, cfg;
677
678 /* set up the PSC for SPI mode */
679 hw->regs->psc_ctrl = PSC_CTRL_DISABLE;
680 wmb(); /* drain writebuffer */
681 hw->regs->psc_sel = PSC_SEL_PS_SPIMODE;
682 wmb(); /* drain writebuffer */
683
684 hw->regs->psc_spicfg = 0;
685 wmb(); /* drain writebuffer */
686
687 hw->regs->psc_ctrl = PSC_CTRL_ENABLE;
688 wmb(); /* drain writebuffer */
689
690 do {
691 stat = hw->regs->psc_spistat;
692 wmb(); /* drain writebuffer */
693 } while ((stat & PSC_SPISTAT_SR) == 0);
694
695
696 cfg = hw->usedma ? 0 : PSC_SPICFG_DD_DISABLE;
697 cfg |= PSC_SPICFG_SET_LEN(8);
698 cfg |= PSC_SPICFG_RT_FIFO8 | PSC_SPICFG_TT_FIFO8;
699 /* use minimal allowed brg and div values as initial setting: */
700 cfg |= PSC_SPICFG_SET_BAUD(4) | PSC_SPICFG_SET_DIV(0);
701
702#ifdef AU1550_SPI_DEBUG_LOOPBACK
703 cfg |= PSC_SPICFG_LB;
704#endif
705
706 hw->regs->psc_spicfg = cfg;
707 wmb(); /* drain writebuffer */
708
709 au1550_spi_mask_ack_all(hw);
710
711 hw->regs->psc_spicfg |= PSC_SPICFG_DE_ENABLE;
712 wmb(); /* drain writebuffer */
713
714 do {
715 stat = hw->regs->psc_spistat;
716 wmb(); /* drain writebuffer */
717 } while ((stat & PSC_SPISTAT_DR) == 0);
718
719 au1550_spi_reset_fifos(hw);
720}
721
722
723static int au1550_spi_probe(struct platform_device *pdev)
724{
725 struct au1550_spi *hw;
726 struct spi_master *master;
727 struct resource *r;
728 int err = 0;
729
730 master = spi_alloc_master(&pdev->dev, sizeof(struct au1550_spi));
731 if (master == NULL) {
732 dev_err(&pdev->dev, "No memory for spi_master\n");
733 err = -ENOMEM;
734 goto err_nomem;
735 }
736
737 /* the spi->mode bits understood by this driver: */
738 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
739 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 24);
740
741 hw = spi_master_get_devdata(master);
742
743 hw->master = master;
744 hw->pdata = dev_get_platdata(&pdev->dev);
745 hw->dev = &pdev->dev;
746
747 if (hw->pdata == NULL) {
748 dev_err(&pdev->dev, "No platform data supplied\n");
749 err = -ENOENT;
750 goto err_no_pdata;
751 }
752
753 r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
754 if (!r) {
755 dev_err(&pdev->dev, "no IRQ\n");
756 err = -ENODEV;
757 goto err_no_iores;
758 }
759 hw->irq = r->start;
760
761 hw->usedma = 0;
762 r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
763 if (r) {
764 hw->dma_tx_id = r->start;
765 r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
766 if (r) {
767 hw->dma_rx_id = r->start;
768 if (usedma && ddma_memid) {
769 if (pdev->dev.dma_mask == NULL)
770 dev_warn(&pdev->dev, "no dma mask\n");
771 else
772 hw->usedma = 1;
773 }
774 }
775 }
776
777 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
778 if (!r) {
779 dev_err(&pdev->dev, "no mmio resource\n");
780 err = -ENODEV;
781 goto err_no_iores;
782 }
783
784 hw->ioarea = request_mem_region(r->start, sizeof(psc_spi_t),
785 pdev->name);
786 if (!hw->ioarea) {
787 dev_err(&pdev->dev, "Cannot reserve iomem region\n");
788 err = -ENXIO;
789 goto err_no_iores;
790 }
791
792 hw->regs = (psc_spi_t __iomem *)ioremap(r->start, sizeof(psc_spi_t));
793 if (!hw->regs) {
794 dev_err(&pdev->dev, "cannot ioremap\n");
795 err = -ENXIO;
796 goto err_ioremap;
797 }
798
799 platform_set_drvdata(pdev, hw);
800
801 init_completion(&hw->master_done);
802
803 hw->bitbang.master = hw->master;
804 hw->bitbang.setup_transfer = au1550_spi_setupxfer;
805 hw->bitbang.chipselect = au1550_spi_chipsel;
806 hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs;
807
808 if (hw->usedma) {
809 hw->dma_tx_ch = au1xxx_dbdma_chan_alloc(ddma_memid,
810 hw->dma_tx_id, NULL, (void *)hw);
811 if (hw->dma_tx_ch == 0) {
812 dev_err(&pdev->dev,
813 "Cannot allocate tx dma channel\n");
814 err = -ENXIO;
815 goto err_no_txdma;
816 }
817 au1xxx_dbdma_set_devwidth(hw->dma_tx_ch, 8);
818 if (au1xxx_dbdma_ring_alloc(hw->dma_tx_ch,
819 AU1550_SPI_DBDMA_DESCRIPTORS) == 0) {
820 dev_err(&pdev->dev,
821 "Cannot allocate tx dma descriptors\n");
822 err = -ENXIO;
823 goto err_no_txdma_descr;
824 }
825
826
827 hw->dma_rx_ch = au1xxx_dbdma_chan_alloc(hw->dma_rx_id,
828 ddma_memid, NULL, (void *)hw);
829 if (hw->dma_rx_ch == 0) {
830 dev_err(&pdev->dev,
831 "Cannot allocate rx dma channel\n");
832 err = -ENXIO;
833 goto err_no_rxdma;
834 }
835 au1xxx_dbdma_set_devwidth(hw->dma_rx_ch, 8);
836 if (au1xxx_dbdma_ring_alloc(hw->dma_rx_ch,
837 AU1550_SPI_DBDMA_DESCRIPTORS) == 0) {
838 dev_err(&pdev->dev,
839 "Cannot allocate rx dma descriptors\n");
840 err = -ENXIO;
841 goto err_no_rxdma_descr;
842 }
843
844 err = au1550_spi_dma_rxtmp_alloc(hw,
845 AU1550_SPI_DMA_RXTMP_MINSIZE);
846 if (err < 0) {
847 dev_err(&pdev->dev,
848 "Cannot allocate initial rx dma tmp buffer\n");
849 goto err_dma_rxtmp_alloc;
850 }
851 }
852
853 au1550_spi_bits_handlers_set(hw, 8);
854
855 err = request_irq(hw->irq, au1550_spi_irq, 0, pdev->name, hw);
856 if (err) {
857 dev_err(&pdev->dev, "Cannot claim IRQ\n");
858 goto err_no_irq;
859 }
860
861 master->bus_num = pdev->id;
862 master->num_chipselect = hw->pdata->num_chipselect;
863
864 /*
865 * precompute valid range for spi freq - from au1550 datasheet:
866 * psc_tempclk = psc_mainclk / (2 << DIV)
867 * spiclk = psc_tempclk / (2 * (BRG + 1))
868 * BRG valid range is 4..63
869 * DIV valid range is 0..3
870 * round the min and max frequencies to values that would still
871 * produce valid brg and div
872 */
873 {
874 int min_div = (2 << 0) * (2 * (4 + 1));
875 int max_div = (2 << 3) * (2 * (63 + 1));
876
877 master->max_speed_hz = hw->pdata->mainclk_hz / min_div;
878 master->min_speed_hz =
879 hw->pdata->mainclk_hz / (max_div + 1) + 1;
880 }
881
882 au1550_spi_setup_psc_as_spi(hw);
883
884 err = spi_bitbang_start(&hw->bitbang);
885 if (err) {
886 dev_err(&pdev->dev, "Failed to register SPI master\n");
887 goto err_register;
888 }
889
890 dev_info(&pdev->dev,
891 "spi master registered: bus_num=%d num_chipselect=%d\n",
892 master->bus_num, master->num_chipselect);
893
894 return 0;
895
896err_register:
897 free_irq(hw->irq, hw);
898
899err_no_irq:
900 au1550_spi_dma_rxtmp_free(hw);
901
902err_dma_rxtmp_alloc:
903err_no_rxdma_descr:
904 if (hw->usedma)
905 au1xxx_dbdma_chan_free(hw->dma_rx_ch);
906
907err_no_rxdma:
908err_no_txdma_descr:
909 if (hw->usedma)
910 au1xxx_dbdma_chan_free(hw->dma_tx_ch);
911
912err_no_txdma:
913 iounmap((void __iomem *)hw->regs);
914
915err_ioremap:
916 release_mem_region(r->start, sizeof(psc_spi_t));
917
918err_no_iores:
919err_no_pdata:
920 spi_master_put(hw->master);
921
922err_nomem:
923 return err;
924}
925
926static int au1550_spi_remove(struct platform_device *pdev)
927{
928 struct au1550_spi *hw = platform_get_drvdata(pdev);
929
930 dev_info(&pdev->dev, "spi master remove: bus_num=%d\n",
931 hw->master->bus_num);
932
933 spi_bitbang_stop(&hw->bitbang);
934 free_irq(hw->irq, hw);
935 iounmap((void __iomem *)hw->regs);
936 release_mem_region(hw->ioarea->start, sizeof(psc_spi_t));
937
938 if (hw->usedma) {
939 au1550_spi_dma_rxtmp_free(hw);
940 au1xxx_dbdma_chan_free(hw->dma_rx_ch);
941 au1xxx_dbdma_chan_free(hw->dma_tx_ch);
942 }
943
944 spi_master_put(hw->master);
945 return 0;
946}
947
948/* work with hotplug and coldplug */
949MODULE_ALIAS("platform:au1550-spi");
950
951static struct platform_driver au1550_spi_drv = {
952 .probe = au1550_spi_probe,
953 .remove = au1550_spi_remove,
954 .driver = {
955 .name = "au1550-spi",
956 },
957};
958
959static int __init au1550_spi_init(void)
960{
961 /*
962 * create memory device with 8 bits dev_devwidth
963 * needed for proper byte ordering to spi fifo
964 */
965 switch (alchemy_get_cputype()) {
966 case ALCHEMY_CPU_AU1550:
967 case ALCHEMY_CPU_AU1200:
968 case ALCHEMY_CPU_AU1300:
969 break;
970 default:
971 return -ENODEV;
972 }
973
974 if (usedma) {
975 ddma_memid = au1xxx_ddma_add_device(&au1550_spi_mem_dbdev);
976 if (!ddma_memid)
977 printk(KERN_ERR "au1550-spi: cannot add memory dbdma device\n");
978 }
979 return platform_driver_register(&au1550_spi_drv);
980}
981module_init(au1550_spi_init);
982
983static void __exit au1550_spi_exit(void)
984{
985 if (usedma && ddma_memid)
986 au1xxx_ddma_del_device(ddma_memid);
987 platform_driver_unregister(&au1550_spi_drv);
988}
989module_exit(au1550_spi_exit);
990
991MODULE_DESCRIPTION("Au1550 PSC SPI Driver");
992MODULE_AUTHOR("Jan Nikitenko <jan.nikitenko@gmail.com>");
993MODULE_LICENSE("GPL");
1/*
2 * 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)
5 *
6 * Copyright (c) 2006 ATRON electronic GmbH
7 * Author: Jan Nikitenko <jan.nikitenko@gmail.com>
8 *
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.
13 *
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.
18 *
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
22 */
23
24#include <linux/init.h>
25#include <linux/interrupt.h>
26#include <linux/slab.h>
27#include <linux/errno.h>
28#include <linux/device.h>
29#include <linux/platform_device.h>
30#include <linux/resource.h>
31#include <linux/spi/spi.h>
32#include <linux/spi/spi_bitbang.h>
33#include <linux/dma-mapping.h>
34#include <linux/completion.h>
35#include <asm/mach-au1x00/au1000.h>
36#include <asm/mach-au1x00/au1xxx_psc.h>
37#include <asm/mach-au1x00/au1xxx_dbdma.h>
38
39#include <asm/mach-au1x00/au1550_spi.h>
40
41static unsigned usedma = 1;
42module_param(usedma, uint, 0644);
43
44/*
45#define AU1550_SPI_DEBUG_LOOPBACK
46*/
47
48
49#define AU1550_SPI_DBDMA_DESCRIPTORS 1
50#define AU1550_SPI_DMA_RXTMP_MINSIZE 2048U
51
52struct au1550_spi {
53 struct spi_bitbang bitbang;
54
55 volatile psc_spi_t __iomem *regs;
56 int irq;
57 unsigned freq_max;
58 unsigned freq_min;
59
60 unsigned len;
61 unsigned tx_count;
62 unsigned rx_count;
63 const u8 *tx;
64 u8 *rx;
65
66 void (*rx_word)(struct au1550_spi *hw);
67 void (*tx_word)(struct au1550_spi *hw);
68 int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
69 irqreturn_t (*irq_callback)(struct au1550_spi *hw);
70
71 struct completion master_done;
72
73 unsigned usedma;
74 u32 dma_tx_id;
75 u32 dma_rx_id;
76 u32 dma_tx_ch;
77 u32 dma_rx_ch;
78
79 u8 *dma_rx_tmpbuf;
80 unsigned dma_rx_tmpbuf_size;
81 u32 dma_rx_tmpbuf_addr;
82
83 struct spi_master *master;
84 struct device *dev;
85 struct au1550_spi_info *pdata;
86 struct resource *ioarea;
87};
88
89
90/* we use an 8-bit memory device for dma transfers to/from spi fifo */
91static dbdev_tab_t au1550_spi_mem_dbdev =
92{
93 .dev_id = DBDMA_MEM_CHAN,
94 .dev_flags = DEV_FLAGS_ANYUSE|DEV_FLAGS_SYNC,
95 .dev_tsize = 0,
96 .dev_devwidth = 8,
97 .dev_physaddr = 0x00000000,
98 .dev_intlevel = 0,
99 .dev_intpolarity = 0
100};
101
102static int ddma_memid; /* id to above mem dma device */
103
104static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw);
105
106
107/*
108 * compute BRG and DIV bits to setup spi clock based on main input clock rate
109 * that was specified in platform data structure
110 * according to au1550 datasheet:
111 * psc_tempclk = psc_mainclk / (2 << DIV)
112 * spiclk = psc_tempclk / (2 * (BRG + 1))
113 * BRG valid range is 4..63
114 * DIV valid range is 0..3
115 */
116static u32 au1550_spi_baudcfg(struct au1550_spi *hw, unsigned speed_hz)
117{
118 u32 mainclk_hz = hw->pdata->mainclk_hz;
119 u32 div, brg;
120
121 for (div = 0; div < 4; div++) {
122 brg = mainclk_hz / speed_hz / (4 << div);
123 /* now we have BRG+1 in brg, so count with that */
124 if (brg < (4 + 1)) {
125 brg = (4 + 1); /* speed_hz too big */
126 break; /* set lowest brg (div is == 0) */
127 }
128 if (brg <= (63 + 1))
129 break; /* we have valid brg and div */
130 }
131 if (div == 4) {
132 div = 3; /* speed_hz too small */
133 brg = (63 + 1); /* set highest brg and div */
134 }
135 brg--;
136 return PSC_SPICFG_SET_BAUD(brg) | PSC_SPICFG_SET_DIV(div);
137}
138
139static inline void au1550_spi_mask_ack_all(struct au1550_spi *hw)
140{
141 hw->regs->psc_spimsk =
142 PSC_SPIMSK_MM | PSC_SPIMSK_RR | PSC_SPIMSK_RO
143 | PSC_SPIMSK_RU | PSC_SPIMSK_TR | PSC_SPIMSK_TO
144 | PSC_SPIMSK_TU | PSC_SPIMSK_SD | PSC_SPIMSK_MD;
145 au_sync();
146
147 hw->regs->psc_spievent =
148 PSC_SPIEVNT_MM | PSC_SPIEVNT_RR | PSC_SPIEVNT_RO
149 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TR | PSC_SPIEVNT_TO
150 | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD | PSC_SPIEVNT_MD;
151 au_sync();
152}
153
154static void au1550_spi_reset_fifos(struct au1550_spi *hw)
155{
156 u32 pcr;
157
158 hw->regs->psc_spipcr = PSC_SPIPCR_RC | PSC_SPIPCR_TC;
159 au_sync();
160 do {
161 pcr = hw->regs->psc_spipcr;
162 au_sync();
163 } while (pcr != 0);
164}
165
166/*
167 * dma transfers are used for the most common spi word size of 8-bits
168 * we cannot easily change already set up dma channels' width, so if we wanted
169 * dma support for more than 8-bit words (up to 24 bits), we would need to
170 * setup dma channels from scratch on each spi transfer, based on bits_per_word
171 * instead we have pre set up 8 bit dma channels supporting spi 4 to 8 bits
172 * transfers, and 9 to 24 bits spi transfers will be done in pio irq based mode
173 * callbacks to handle dma or pio are set up in au1550_spi_bits_handlers_set()
174 */
175static void au1550_spi_chipsel(struct spi_device *spi, int value)
176{
177 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
178 unsigned cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
179 u32 cfg, stat;
180
181 switch (value) {
182 case BITBANG_CS_INACTIVE:
183 if (hw->pdata->deactivate_cs)
184 hw->pdata->deactivate_cs(hw->pdata, spi->chip_select,
185 cspol);
186 break;
187
188 case BITBANG_CS_ACTIVE:
189 au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
190
191 cfg = hw->regs->psc_spicfg;
192 au_sync();
193 hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
194 au_sync();
195
196 if (spi->mode & SPI_CPOL)
197 cfg |= PSC_SPICFG_BI;
198 else
199 cfg &= ~PSC_SPICFG_BI;
200 if (spi->mode & SPI_CPHA)
201 cfg &= ~PSC_SPICFG_CDE;
202 else
203 cfg |= PSC_SPICFG_CDE;
204
205 if (spi->mode & SPI_LSB_FIRST)
206 cfg |= PSC_SPICFG_MLF;
207 else
208 cfg &= ~PSC_SPICFG_MLF;
209
210 if (hw->usedma && spi->bits_per_word <= 8)
211 cfg &= ~PSC_SPICFG_DD_DISABLE;
212 else
213 cfg |= PSC_SPICFG_DD_DISABLE;
214 cfg = PSC_SPICFG_CLR_LEN(cfg);
215 cfg |= PSC_SPICFG_SET_LEN(spi->bits_per_word);
216
217 cfg = PSC_SPICFG_CLR_BAUD(cfg);
218 cfg &= ~PSC_SPICFG_SET_DIV(3);
219 cfg |= au1550_spi_baudcfg(hw, spi->max_speed_hz);
220
221 hw->regs->psc_spicfg = cfg | PSC_SPICFG_DE_ENABLE;
222 au_sync();
223 do {
224 stat = hw->regs->psc_spistat;
225 au_sync();
226 } while ((stat & PSC_SPISTAT_DR) == 0);
227
228 if (hw->pdata->activate_cs)
229 hw->pdata->activate_cs(hw->pdata, spi->chip_select,
230 cspol);
231 break;
232 }
233}
234
235static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t)
236{
237 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
238 unsigned bpw, hz;
239 u32 cfg, stat;
240
241 bpw = spi->bits_per_word;
242 hz = spi->max_speed_hz;
243 if (t) {
244 if (t->bits_per_word)
245 bpw = t->bits_per_word;
246 if (t->speed_hz)
247 hz = t->speed_hz;
248 }
249
250 if (bpw < 4 || bpw > 24) {
251 dev_err(&spi->dev, "setupxfer: invalid bits_per_word=%d\n",
252 bpw);
253 return -EINVAL;
254 }
255 if (hz > spi->max_speed_hz || hz > hw->freq_max || hz < hw->freq_min) {
256 dev_err(&spi->dev, "setupxfer: clock rate=%d out of range\n",
257 hz);
258 return -EINVAL;
259 }
260
261 au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
262
263 cfg = hw->regs->psc_spicfg;
264 au_sync();
265 hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
266 au_sync();
267
268 if (hw->usedma && bpw <= 8)
269 cfg &= ~PSC_SPICFG_DD_DISABLE;
270 else
271 cfg |= PSC_SPICFG_DD_DISABLE;
272 cfg = PSC_SPICFG_CLR_LEN(cfg);
273 cfg |= PSC_SPICFG_SET_LEN(bpw);
274
275 cfg = PSC_SPICFG_CLR_BAUD(cfg);
276 cfg &= ~PSC_SPICFG_SET_DIV(3);
277 cfg |= au1550_spi_baudcfg(hw, hz);
278
279 hw->regs->psc_spicfg = cfg;
280 au_sync();
281
282 if (cfg & PSC_SPICFG_DE_ENABLE) {
283 do {
284 stat = hw->regs->psc_spistat;
285 au_sync();
286 } while ((stat & PSC_SPISTAT_DR) == 0);
287 }
288
289 au1550_spi_reset_fifos(hw);
290 au1550_spi_mask_ack_all(hw);
291 return 0;
292}
293
294static int au1550_spi_setup(struct spi_device *spi)
295{
296 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
297
298 if (spi->bits_per_word < 4 || spi->bits_per_word > 24) {
299 dev_err(&spi->dev, "setup: invalid bits_per_word=%d\n",
300 spi->bits_per_word);
301 return -EINVAL;
302 }
303
304 if (spi->max_speed_hz == 0)
305 spi->max_speed_hz = hw->freq_max;
306 if (spi->max_speed_hz > hw->freq_max
307 || spi->max_speed_hz < hw->freq_min)
308 return -EINVAL;
309 /*
310 * NOTE: cannot change speed and other hw settings immediately,
311 * otherwise sharing of spi bus is not possible,
312 * so do not call setupxfer(spi, NULL) here
313 */
314 return 0;
315}
316
317/*
318 * for dma spi transfers, we have to setup rx channel, otherwise there is
319 * no reliable way how to recognize that spi transfer is done
320 * dma complete callbacks are called before real spi transfer is finished
321 * and if only tx dma channel is set up (and rx fifo overflow event masked)
322 * spi master done event irq is not generated unless rx fifo is empty (emptied)
323 * so we need rx tmp buffer to use for rx dma if user does not provide one
324 */
325static int au1550_spi_dma_rxtmp_alloc(struct au1550_spi *hw, unsigned size)
326{
327 hw->dma_rx_tmpbuf = kmalloc(size, GFP_KERNEL);
328 if (!hw->dma_rx_tmpbuf)
329 return -ENOMEM;
330 hw->dma_rx_tmpbuf_size = size;
331 hw->dma_rx_tmpbuf_addr = dma_map_single(hw->dev, hw->dma_rx_tmpbuf,
332 size, DMA_FROM_DEVICE);
333 if (dma_mapping_error(hw->dev, hw->dma_rx_tmpbuf_addr)) {
334 kfree(hw->dma_rx_tmpbuf);
335 hw->dma_rx_tmpbuf = 0;
336 hw->dma_rx_tmpbuf_size = 0;
337 return -EFAULT;
338 }
339 return 0;
340}
341
342static void au1550_spi_dma_rxtmp_free(struct au1550_spi *hw)
343{
344 dma_unmap_single(hw->dev, hw->dma_rx_tmpbuf_addr,
345 hw->dma_rx_tmpbuf_size, DMA_FROM_DEVICE);
346 kfree(hw->dma_rx_tmpbuf);
347 hw->dma_rx_tmpbuf = 0;
348 hw->dma_rx_tmpbuf_size = 0;
349}
350
351static int au1550_spi_dma_txrxb(struct spi_device *spi, struct spi_transfer *t)
352{
353 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
354 dma_addr_t dma_tx_addr;
355 dma_addr_t dma_rx_addr;
356 u32 res;
357
358 hw->len = t->len;
359 hw->tx_count = 0;
360 hw->rx_count = 0;
361
362 hw->tx = t->tx_buf;
363 hw->rx = t->rx_buf;
364 dma_tx_addr = t->tx_dma;
365 dma_rx_addr = t->rx_dma;
366
367 /*
368 * check if buffers are already dma mapped, map them otherwise:
369 * - first map the TX buffer, so cache data gets written to memory
370 * - then map the RX buffer, so that cache entries (with
371 * soon-to-be-stale data) get removed
372 * use rx buffer in place of tx if tx buffer was not provided
373 * use temp rx buffer (preallocated or realloc to fit) for rx dma
374 */
375 if (t->tx_buf) {
376 if (t->tx_dma == 0) { /* if DMA_ADDR_INVALID, map it */
377 dma_tx_addr = dma_map_single(hw->dev,
378 (void *)t->tx_buf,
379 t->len, DMA_TO_DEVICE);
380 if (dma_mapping_error(hw->dev, dma_tx_addr))
381 dev_err(hw->dev, "tx dma map error\n");
382 }
383 }
384
385 if (t->rx_buf) {
386 if (t->rx_dma == 0) { /* if DMA_ADDR_INVALID, map it */
387 dma_rx_addr = dma_map_single(hw->dev,
388 (void *)t->rx_buf,
389 t->len, DMA_FROM_DEVICE);
390 if (dma_mapping_error(hw->dev, dma_rx_addr))
391 dev_err(hw->dev, "rx dma map error\n");
392 }
393 } else {
394 if (t->len > hw->dma_rx_tmpbuf_size) {
395 int ret;
396
397 au1550_spi_dma_rxtmp_free(hw);
398 ret = au1550_spi_dma_rxtmp_alloc(hw, max(t->len,
399 AU1550_SPI_DMA_RXTMP_MINSIZE));
400 if (ret < 0)
401 return ret;
402 }
403 hw->rx = hw->dma_rx_tmpbuf;
404 dma_rx_addr = hw->dma_rx_tmpbuf_addr;
405 dma_sync_single_for_device(hw->dev, dma_rx_addr,
406 t->len, DMA_FROM_DEVICE);
407 }
408
409 if (!t->tx_buf) {
410 dma_sync_single_for_device(hw->dev, dma_rx_addr,
411 t->len, DMA_BIDIRECTIONAL);
412 hw->tx = hw->rx;
413 }
414
415 /* put buffers on the ring */
416 res = au1xxx_dbdma_put_dest(hw->dma_rx_ch, virt_to_phys(hw->rx),
417 t->len, DDMA_FLAGS_IE);
418 if (!res)
419 dev_err(hw->dev, "rx dma put dest error\n");
420
421 res = au1xxx_dbdma_put_source(hw->dma_tx_ch, virt_to_phys(hw->tx),
422 t->len, DDMA_FLAGS_IE);
423 if (!res)
424 dev_err(hw->dev, "tx dma put source error\n");
425
426 au1xxx_dbdma_start(hw->dma_rx_ch);
427 au1xxx_dbdma_start(hw->dma_tx_ch);
428
429 /* by default enable nearly all events interrupt */
430 hw->regs->psc_spimsk = PSC_SPIMSK_SD;
431 au_sync();
432
433 /* start the transfer */
434 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
435 au_sync();
436
437 wait_for_completion(&hw->master_done);
438
439 au1xxx_dbdma_stop(hw->dma_tx_ch);
440 au1xxx_dbdma_stop(hw->dma_rx_ch);
441
442 if (!t->rx_buf) {
443 /* using the temporal preallocated and premapped buffer */
444 dma_sync_single_for_cpu(hw->dev, dma_rx_addr, t->len,
445 DMA_FROM_DEVICE);
446 }
447 /* unmap buffers if mapped above */
448 if (t->rx_buf && t->rx_dma == 0 )
449 dma_unmap_single(hw->dev, dma_rx_addr, t->len,
450 DMA_FROM_DEVICE);
451 if (t->tx_buf && t->tx_dma == 0 )
452 dma_unmap_single(hw->dev, dma_tx_addr, t->len,
453 DMA_TO_DEVICE);
454
455 return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count;
456}
457
458static irqreturn_t au1550_spi_dma_irq_callback(struct au1550_spi *hw)
459{
460 u32 stat, evnt;
461
462 stat = hw->regs->psc_spistat;
463 evnt = hw->regs->psc_spievent;
464 au_sync();
465 if ((stat & PSC_SPISTAT_DI) == 0) {
466 dev_err(hw->dev, "Unexpected IRQ!\n");
467 return IRQ_NONE;
468 }
469
470 if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO
471 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO
472 | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD))
473 != 0) {
474 /*
475 * due to an spi error we consider transfer as done,
476 * so mask all events until before next transfer start
477 * and stop the possibly running dma immediatelly
478 */
479 au1550_spi_mask_ack_all(hw);
480 au1xxx_dbdma_stop(hw->dma_rx_ch);
481 au1xxx_dbdma_stop(hw->dma_tx_ch);
482
483 /* get number of transferred bytes */
484 hw->rx_count = hw->len - au1xxx_get_dma_residue(hw->dma_rx_ch);
485 hw->tx_count = hw->len - au1xxx_get_dma_residue(hw->dma_tx_ch);
486
487 au1xxx_dbdma_reset(hw->dma_rx_ch);
488 au1xxx_dbdma_reset(hw->dma_tx_ch);
489 au1550_spi_reset_fifos(hw);
490
491 if (evnt == PSC_SPIEVNT_RO)
492 dev_err(hw->dev,
493 "dma transfer: receive FIFO overflow!\n");
494 else
495 dev_err(hw->dev,
496 "dma transfer: unexpected SPI error "
497 "(event=0x%x stat=0x%x)!\n", evnt, stat);
498
499 complete(&hw->master_done);
500 return IRQ_HANDLED;
501 }
502
503 if ((evnt & PSC_SPIEVNT_MD) != 0) {
504 /* transfer completed successfully */
505 au1550_spi_mask_ack_all(hw);
506 hw->rx_count = hw->len;
507 hw->tx_count = hw->len;
508 complete(&hw->master_done);
509 }
510 return IRQ_HANDLED;
511}
512
513
514/* routines to handle different word sizes in pio mode */
515#define AU1550_SPI_RX_WORD(size, mask) \
516static void au1550_spi_rx_word_##size(struct au1550_spi *hw) \
517{ \
518 u32 fifoword = hw->regs->psc_spitxrx & (u32)(mask); \
519 au_sync(); \
520 if (hw->rx) { \
521 *(u##size *)hw->rx = (u##size)fifoword; \
522 hw->rx += (size) / 8; \
523 } \
524 hw->rx_count += (size) / 8; \
525}
526
527#define AU1550_SPI_TX_WORD(size, mask) \
528static void au1550_spi_tx_word_##size(struct au1550_spi *hw) \
529{ \
530 u32 fifoword = 0; \
531 if (hw->tx) { \
532 fifoword = *(u##size *)hw->tx & (u32)(mask); \
533 hw->tx += (size) / 8; \
534 } \
535 hw->tx_count += (size) / 8; \
536 if (hw->tx_count >= hw->len) \
537 fifoword |= PSC_SPITXRX_LC; \
538 hw->regs->psc_spitxrx = fifoword; \
539 au_sync(); \
540}
541
542AU1550_SPI_RX_WORD(8,0xff)
543AU1550_SPI_RX_WORD(16,0xffff)
544AU1550_SPI_RX_WORD(32,0xffffff)
545AU1550_SPI_TX_WORD(8,0xff)
546AU1550_SPI_TX_WORD(16,0xffff)
547AU1550_SPI_TX_WORD(32,0xffffff)
548
549static int au1550_spi_pio_txrxb(struct spi_device *spi, struct spi_transfer *t)
550{
551 u32 stat, mask;
552 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
553
554 hw->tx = t->tx_buf;
555 hw->rx = t->rx_buf;
556 hw->len = t->len;
557 hw->tx_count = 0;
558 hw->rx_count = 0;
559
560 /* by default enable nearly all events after filling tx fifo */
561 mask = PSC_SPIMSK_SD;
562
563 /* fill the transmit FIFO */
564 while (hw->tx_count < hw->len) {
565
566 hw->tx_word(hw);
567
568 if (hw->tx_count >= hw->len) {
569 /* mask tx fifo request interrupt as we are done */
570 mask |= PSC_SPIMSK_TR;
571 }
572
573 stat = hw->regs->psc_spistat;
574 au_sync();
575 if (stat & PSC_SPISTAT_TF)
576 break;
577 }
578
579 /* enable event interrupts */
580 hw->regs->psc_spimsk = mask;
581 au_sync();
582
583 /* start the transfer */
584 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
585 au_sync();
586
587 wait_for_completion(&hw->master_done);
588
589 return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count;
590}
591
592static irqreturn_t au1550_spi_pio_irq_callback(struct au1550_spi *hw)
593{
594 int busy;
595 u32 stat, evnt;
596
597 stat = hw->regs->psc_spistat;
598 evnt = hw->regs->psc_spievent;
599 au_sync();
600 if ((stat & PSC_SPISTAT_DI) == 0) {
601 dev_err(hw->dev, "Unexpected IRQ!\n");
602 return IRQ_NONE;
603 }
604
605 if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO
606 | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO
607 | PSC_SPIEVNT_SD))
608 != 0) {
609 /*
610 * due to an error we consider transfer as done,
611 * so mask all events until before next transfer start
612 */
613 au1550_spi_mask_ack_all(hw);
614 au1550_spi_reset_fifos(hw);
615 dev_err(hw->dev,
616 "pio transfer: unexpected SPI error "
617 "(event=0x%x stat=0x%x)!\n", evnt, stat);
618 complete(&hw->master_done);
619 return IRQ_HANDLED;
620 }
621
622 /*
623 * while there is something to read from rx fifo
624 * or there is a space to write to tx fifo:
625 */
626 do {
627 busy = 0;
628 stat = hw->regs->psc_spistat;
629 au_sync();
630
631 /*
632 * Take care to not let the Rx FIFO overflow.
633 *
634 * We only write a byte if we have read one at least. Initially,
635 * the write fifo is full, so we should read from the read fifo
636 * first.
637 * In case we miss a word from the read fifo, we should get a
638 * RO event and should back out.
639 */
640 if (!(stat & PSC_SPISTAT_RE) && hw->rx_count < hw->len) {
641 hw->rx_word(hw);
642 busy = 1;
643
644 if (!(stat & PSC_SPISTAT_TF) && hw->tx_count < hw->len)
645 hw->tx_word(hw);
646 }
647 } while (busy);
648
649 hw->regs->psc_spievent = PSC_SPIEVNT_RR | PSC_SPIEVNT_TR;
650 au_sync();
651
652 /*
653 * Restart the SPI transmission in case of a transmit underflow.
654 * This seems to work despite the notes in the Au1550 data book
655 * of Figure 8-4 with flowchart for SPI master operation:
656 *
657 * """Note 1: An XFR Error Interrupt occurs, unless masked,
658 * for any of the following events: Tx FIFO Underflow,
659 * Rx FIFO Overflow, or Multiple-master Error
660 * Note 2: In case of a Tx Underflow Error, all zeroes are
661 * transmitted."""
662 *
663 * By simply restarting the spi transfer on Tx Underflow Error,
664 * we assume that spi transfer was paused instead of zeroes
665 * transmittion mentioned in the Note 2 of Au1550 data book.
666 */
667 if (evnt & PSC_SPIEVNT_TU) {
668 hw->regs->psc_spievent = PSC_SPIEVNT_TU | PSC_SPIEVNT_MD;
669 au_sync();
670 hw->regs->psc_spipcr = PSC_SPIPCR_MS;
671 au_sync();
672 }
673
674 if (hw->rx_count >= hw->len) {
675 /* transfer completed successfully */
676 au1550_spi_mask_ack_all(hw);
677 complete(&hw->master_done);
678 }
679 return IRQ_HANDLED;
680}
681
682static int au1550_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
683{
684 struct au1550_spi *hw = spi_master_get_devdata(spi->master);
685 return hw->txrx_bufs(spi, t);
686}
687
688static irqreturn_t au1550_spi_irq(int irq, void *dev)
689{
690 struct au1550_spi *hw = dev;
691 return hw->irq_callback(hw);
692}
693
694static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw)
695{
696 if (bpw <= 8) {
697 if (hw->usedma) {
698 hw->txrx_bufs = &au1550_spi_dma_txrxb;
699 hw->irq_callback = &au1550_spi_dma_irq_callback;
700 } else {
701 hw->rx_word = &au1550_spi_rx_word_8;
702 hw->tx_word = &au1550_spi_tx_word_8;
703 hw->txrx_bufs = &au1550_spi_pio_txrxb;
704 hw->irq_callback = &au1550_spi_pio_irq_callback;
705 }
706 } else if (bpw <= 16) {
707 hw->rx_word = &au1550_spi_rx_word_16;
708 hw->tx_word = &au1550_spi_tx_word_16;
709 hw->txrx_bufs = &au1550_spi_pio_txrxb;
710 hw->irq_callback = &au1550_spi_pio_irq_callback;
711 } else {
712 hw->rx_word = &au1550_spi_rx_word_32;
713 hw->tx_word = &au1550_spi_tx_word_32;
714 hw->txrx_bufs = &au1550_spi_pio_txrxb;
715 hw->irq_callback = &au1550_spi_pio_irq_callback;
716 }
717}
718
719static void __init au1550_spi_setup_psc_as_spi(struct au1550_spi *hw)
720{
721 u32 stat, cfg;
722
723 /* set up the PSC for SPI mode */
724 hw->regs->psc_ctrl = PSC_CTRL_DISABLE;
725 au_sync();
726 hw->regs->psc_sel = PSC_SEL_PS_SPIMODE;
727 au_sync();
728
729 hw->regs->psc_spicfg = 0;
730 au_sync();
731
732 hw->regs->psc_ctrl = PSC_CTRL_ENABLE;
733 au_sync();
734
735 do {
736 stat = hw->regs->psc_spistat;
737 au_sync();
738 } while ((stat & PSC_SPISTAT_SR) == 0);
739
740
741 cfg = hw->usedma ? 0 : PSC_SPICFG_DD_DISABLE;
742 cfg |= PSC_SPICFG_SET_LEN(8);
743 cfg |= PSC_SPICFG_RT_FIFO8 | PSC_SPICFG_TT_FIFO8;
744 /* use minimal allowed brg and div values as initial setting: */
745 cfg |= PSC_SPICFG_SET_BAUD(4) | PSC_SPICFG_SET_DIV(0);
746
747#ifdef AU1550_SPI_DEBUG_LOOPBACK
748 cfg |= PSC_SPICFG_LB;
749#endif
750
751 hw->regs->psc_spicfg = cfg;
752 au_sync();
753
754 au1550_spi_mask_ack_all(hw);
755
756 hw->regs->psc_spicfg |= PSC_SPICFG_DE_ENABLE;
757 au_sync();
758
759 do {
760 stat = hw->regs->psc_spistat;
761 au_sync();
762 } while ((stat & PSC_SPISTAT_DR) == 0);
763
764 au1550_spi_reset_fifos(hw);
765}
766
767
768static int __init au1550_spi_probe(struct platform_device *pdev)
769{
770 struct au1550_spi *hw;
771 struct spi_master *master;
772 struct resource *r;
773 int err = 0;
774
775 master = spi_alloc_master(&pdev->dev, sizeof(struct au1550_spi));
776 if (master == NULL) {
777 dev_err(&pdev->dev, "No memory for spi_master\n");
778 err = -ENOMEM;
779 goto err_nomem;
780 }
781
782 /* the spi->mode bits understood by this driver: */
783 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
784
785 hw = spi_master_get_devdata(master);
786
787 hw->master = spi_master_get(master);
788 hw->pdata = pdev->dev.platform_data;
789 hw->dev = &pdev->dev;
790
791 if (hw->pdata == NULL) {
792 dev_err(&pdev->dev, "No platform data supplied\n");
793 err = -ENOENT;
794 goto err_no_pdata;
795 }
796
797 r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
798 if (!r) {
799 dev_err(&pdev->dev, "no IRQ\n");
800 err = -ENODEV;
801 goto err_no_iores;
802 }
803 hw->irq = r->start;
804
805 hw->usedma = 0;
806 r = platform_get_resource(pdev, IORESOURCE_DMA, 0);
807 if (r) {
808 hw->dma_tx_id = r->start;
809 r = platform_get_resource(pdev, IORESOURCE_DMA, 1);
810 if (r) {
811 hw->dma_rx_id = r->start;
812 if (usedma && ddma_memid) {
813 if (pdev->dev.dma_mask == NULL)
814 dev_warn(&pdev->dev, "no dma mask\n");
815 else
816 hw->usedma = 1;
817 }
818 }
819 }
820
821 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
822 if (!r) {
823 dev_err(&pdev->dev, "no mmio resource\n");
824 err = -ENODEV;
825 goto err_no_iores;
826 }
827
828 hw->ioarea = request_mem_region(r->start, sizeof(psc_spi_t),
829 pdev->name);
830 if (!hw->ioarea) {
831 dev_err(&pdev->dev, "Cannot reserve iomem region\n");
832 err = -ENXIO;
833 goto err_no_iores;
834 }
835
836 hw->regs = (psc_spi_t __iomem *)ioremap(r->start, sizeof(psc_spi_t));
837 if (!hw->regs) {
838 dev_err(&pdev->dev, "cannot ioremap\n");
839 err = -ENXIO;
840 goto err_ioremap;
841 }
842
843 platform_set_drvdata(pdev, hw);
844
845 init_completion(&hw->master_done);
846
847 hw->bitbang.master = hw->master;
848 hw->bitbang.setup_transfer = au1550_spi_setupxfer;
849 hw->bitbang.chipselect = au1550_spi_chipsel;
850 hw->bitbang.master->setup = au1550_spi_setup;
851 hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs;
852
853 if (hw->usedma) {
854 hw->dma_tx_ch = au1xxx_dbdma_chan_alloc(ddma_memid,
855 hw->dma_tx_id, NULL, (void *)hw);
856 if (hw->dma_tx_ch == 0) {
857 dev_err(&pdev->dev,
858 "Cannot allocate tx dma channel\n");
859 err = -ENXIO;
860 goto err_no_txdma;
861 }
862 au1xxx_dbdma_set_devwidth(hw->dma_tx_ch, 8);
863 if (au1xxx_dbdma_ring_alloc(hw->dma_tx_ch,
864 AU1550_SPI_DBDMA_DESCRIPTORS) == 0) {
865 dev_err(&pdev->dev,
866 "Cannot allocate tx dma descriptors\n");
867 err = -ENXIO;
868 goto err_no_txdma_descr;
869 }
870
871
872 hw->dma_rx_ch = au1xxx_dbdma_chan_alloc(hw->dma_rx_id,
873 ddma_memid, NULL, (void *)hw);
874 if (hw->dma_rx_ch == 0) {
875 dev_err(&pdev->dev,
876 "Cannot allocate rx dma channel\n");
877 err = -ENXIO;
878 goto err_no_rxdma;
879 }
880 au1xxx_dbdma_set_devwidth(hw->dma_rx_ch, 8);
881 if (au1xxx_dbdma_ring_alloc(hw->dma_rx_ch,
882 AU1550_SPI_DBDMA_DESCRIPTORS) == 0) {
883 dev_err(&pdev->dev,
884 "Cannot allocate rx dma descriptors\n");
885 err = -ENXIO;
886 goto err_no_rxdma_descr;
887 }
888
889 err = au1550_spi_dma_rxtmp_alloc(hw,
890 AU1550_SPI_DMA_RXTMP_MINSIZE);
891 if (err < 0) {
892 dev_err(&pdev->dev,
893 "Cannot allocate initial rx dma tmp buffer\n");
894 goto err_dma_rxtmp_alloc;
895 }
896 }
897
898 au1550_spi_bits_handlers_set(hw, 8);
899
900 err = request_irq(hw->irq, au1550_spi_irq, 0, pdev->name, hw);
901 if (err) {
902 dev_err(&pdev->dev, "Cannot claim IRQ\n");
903 goto err_no_irq;
904 }
905
906 master->bus_num = pdev->id;
907 master->num_chipselect = hw->pdata->num_chipselect;
908
909 /*
910 * precompute valid range for spi freq - from au1550 datasheet:
911 * psc_tempclk = psc_mainclk / (2 << DIV)
912 * spiclk = psc_tempclk / (2 * (BRG + 1))
913 * BRG valid range is 4..63
914 * DIV valid range is 0..3
915 * round the min and max frequencies to values that would still
916 * produce valid brg and div
917 */
918 {
919 int min_div = (2 << 0) * (2 * (4 + 1));
920 int max_div = (2 << 3) * (2 * (63 + 1));
921 hw->freq_max = hw->pdata->mainclk_hz / min_div;
922 hw->freq_min = hw->pdata->mainclk_hz / (max_div + 1) + 1;
923 }
924
925 au1550_spi_setup_psc_as_spi(hw);
926
927 err = spi_bitbang_start(&hw->bitbang);
928 if (err) {
929 dev_err(&pdev->dev, "Failed to register SPI master\n");
930 goto err_register;
931 }
932
933 dev_info(&pdev->dev,
934 "spi master registered: bus_num=%d num_chipselect=%d\n",
935 master->bus_num, master->num_chipselect);
936
937 return 0;
938
939err_register:
940 free_irq(hw->irq, hw);
941
942err_no_irq:
943 au1550_spi_dma_rxtmp_free(hw);
944
945err_dma_rxtmp_alloc:
946err_no_rxdma_descr:
947 if (hw->usedma)
948 au1xxx_dbdma_chan_free(hw->dma_rx_ch);
949
950err_no_rxdma:
951err_no_txdma_descr:
952 if (hw->usedma)
953 au1xxx_dbdma_chan_free(hw->dma_tx_ch);
954
955err_no_txdma:
956 iounmap((void __iomem *)hw->regs);
957
958err_ioremap:
959 release_resource(hw->ioarea);
960 kfree(hw->ioarea);
961
962err_no_iores:
963err_no_pdata:
964 spi_master_put(hw->master);
965
966err_nomem:
967 return err;
968}
969
970static int __exit au1550_spi_remove(struct platform_device *pdev)
971{
972 struct au1550_spi *hw = platform_get_drvdata(pdev);
973
974 dev_info(&pdev->dev, "spi master remove: bus_num=%d\n",
975 hw->master->bus_num);
976
977 spi_bitbang_stop(&hw->bitbang);
978 free_irq(hw->irq, hw);
979 iounmap((void __iomem *)hw->regs);
980 release_resource(hw->ioarea);
981 kfree(hw->ioarea);
982
983 if (hw->usedma) {
984 au1550_spi_dma_rxtmp_free(hw);
985 au1xxx_dbdma_chan_free(hw->dma_rx_ch);
986 au1xxx_dbdma_chan_free(hw->dma_tx_ch);
987 }
988
989 platform_set_drvdata(pdev, NULL);
990
991 spi_master_put(hw->master);
992 return 0;
993}
994
995/* work with hotplug and coldplug */
996MODULE_ALIAS("platform:au1550-spi");
997
998static struct platform_driver au1550_spi_drv = {
999 .remove = __exit_p(au1550_spi_remove),
1000 .driver = {
1001 .name = "au1550-spi",
1002 .owner = THIS_MODULE,
1003 },
1004};
1005
1006static int __init au1550_spi_init(void)
1007{
1008 /*
1009 * create memory device with 8 bits dev_devwidth
1010 * needed for proper byte ordering to spi fifo
1011 */
1012 if (usedma) {
1013 ddma_memid = au1xxx_ddma_add_device(&au1550_spi_mem_dbdev);
1014 if (!ddma_memid)
1015 printk(KERN_ERR "au1550-spi: cannot add memory"
1016 "dbdma device\n");
1017 }
1018 return platform_driver_probe(&au1550_spi_drv, au1550_spi_probe);
1019}
1020module_init(au1550_spi_init);
1021
1022static void __exit au1550_spi_exit(void)
1023{
1024 if (usedma && ddma_memid)
1025 au1xxx_ddma_del_device(ddma_memid);
1026 platform_driver_unregister(&au1550_spi_drv);
1027}
1028module_exit(au1550_spi_exit);
1029
1030MODULE_DESCRIPTION("Au1550 PSC SPI Driver");
1031MODULE_AUTHOR("Jan Nikitenko <jan.nikitenko@gmail.com>");
1032MODULE_LICENSE("GPL");