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epca.c: reformat comments and coding style improvements
[linux-2.6/openmoko-kernel.git] / drivers / spi / spi_imx.c
blob3b4650ae6f1ab14acd070d9b87f0faa75c1e3ce2
1 /*
2 * drivers/spi/spi_imx.c
3 *
4 * Copyright (C) 2006 SWAPP
5 * Andrea Paterniani <a.paterniani@swapp-eng.it>
6 *
7 * Initial version inspired by:
8 * linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 */
20
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/device.h>
24 #include <linux/ioport.h>
25 #include <linux/errno.h>
26 #include <linux/interrupt.h>
27 #include <linux/platform_device.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/spi/spi.h>
30 #include <linux/workqueue.h>
31 #include <linux/delay.h>
32
33 #include <asm/io.h>
34 #include <asm/irq.h>
35 #include <asm/hardware.h>
36 #include <asm/delay.h>
37
38 #include <asm/arch/hardware.h>
39 #include <asm/arch/imx-dma.h>
40 #include <asm/arch/spi_imx.h>
41
42 /*-------------------------------------------------------------------------*/
43 /* SPI Registers offsets from peripheral base address */
44 #define SPI_RXDATA (0x00)
45 #define SPI_TXDATA (0x04)
46 #define SPI_CONTROL (0x08)
47 #define SPI_INT_STATUS (0x0C)
48 #define SPI_TEST (0x10)
49 #define SPI_PERIOD (0x14)
50 #define SPI_DMA (0x18)
51 #define SPI_RESET (0x1C)
52
53 /* SPI Control Register Bit Fields & Masks */
54 #define SPI_CONTROL_BITCOUNT_MASK (0xF) /* Bit Count Mask */
55 #define SPI_CONTROL_BITCOUNT(n) (((n) - 1) & SPI_CONTROL_BITCOUNT_MASK)
56 #define SPI_CONTROL_POL (0x1 << 4) /* Clock Polarity Mask */
57 #define SPI_CONTROL_POL_ACT_HIGH (0x0 << 4) /* Active high pol. (0=idle) */
58 #define SPI_CONTROL_POL_ACT_LOW (0x1 << 4) /* Active low pol. (1=idle) */
59 #define SPI_CONTROL_PHA (0x1 << 5) /* Clock Phase Mask */
60 #define SPI_CONTROL_PHA_0 (0x0 << 5) /* Clock Phase 0 */
61 #define SPI_CONTROL_PHA_1 (0x1 << 5) /* Clock Phase 1 */
62 #define SPI_CONTROL_SSCTL (0x1 << 6) /* /SS Waveform Select Mask */
63 #define SPI_CONTROL_SSCTL_0 (0x0 << 6) /* Master: /SS stays low between SPI burst
64 Slave: RXFIFO advanced by BIT_COUNT */
65 #define SPI_CONTROL_SSCTL_1 (0x1 << 6) /* Master: /SS insert pulse between SPI burst
66 Slave: RXFIFO advanced by /SS rising edge */
67 #define SPI_CONTROL_SSPOL (0x1 << 7) /* /SS Polarity Select Mask */
68 #define SPI_CONTROL_SSPOL_ACT_LOW (0x0 << 7) /* /SS Active low */
69 #define SPI_CONTROL_SSPOL_ACT_HIGH (0x1 << 7) /* /SS Active high */
70 #define SPI_CONTROL_XCH (0x1 << 8) /* Exchange */
71 #define SPI_CONTROL_SPIEN (0x1 << 9) /* SPI Module Enable */
72 #define SPI_CONTROL_MODE (0x1 << 10) /* SPI Mode Select Mask */
73 #define SPI_CONTROL_MODE_SLAVE (0x0 << 10) /* SPI Mode Slave */
74 #define SPI_CONTROL_MODE_MASTER (0x1 << 10) /* SPI Mode Master */
75 #define SPI_CONTROL_DRCTL (0x3 << 11) /* /SPI_RDY Control Mask */
76 #define SPI_CONTROL_DRCTL_0 (0x0 << 11) /* Ignore /SPI_RDY */
77 #define SPI_CONTROL_DRCTL_1 (0x1 << 11) /* /SPI_RDY falling edge triggers input */
78 #define SPI_CONTROL_DRCTL_2 (0x2 << 11) /* /SPI_RDY active low level triggers input */
79 #define SPI_CONTROL_DATARATE (0x7 << 13) /* Data Rate Mask */
80 #define SPI_PERCLK2_DIV_MIN (0) /* PERCLK2:4 */
81 #define SPI_PERCLK2_DIV_MAX (7) /* PERCLK2:512 */
82 #define SPI_CONTROL_DATARATE_MIN (SPI_PERCLK2_DIV_MAX << 13)
83 #define SPI_CONTROL_DATARATE_MAX (SPI_PERCLK2_DIV_MIN << 13)
84 #define SPI_CONTROL_DATARATE_BAD (SPI_CONTROL_DATARATE_MIN + 1)
85
86 /* SPI Interrupt/Status Register Bit Fields & Masks */
87 #define SPI_STATUS_TE (0x1 << 0) /* TXFIFO Empty Status */
88 #define SPI_STATUS_TH (0x1 << 1) /* TXFIFO Half Status */
89 #define SPI_STATUS_TF (0x1 << 2) /* TXFIFO Full Status */
90 #define SPI_STATUS_RR (0x1 << 3) /* RXFIFO Data Ready Status */
91 #define SPI_STATUS_RH (0x1 << 4) /* RXFIFO Half Status */
92 #define SPI_STATUS_RF (0x1 << 5) /* RXFIFO Full Status */
93 #define SPI_STATUS_RO (0x1 << 6) /* RXFIFO Overflow */
94 #define SPI_STATUS_BO (0x1 << 7) /* Bit Count Overflow */
95 #define SPI_STATUS (0xFF) /* SPI Status Mask */
96 #define SPI_INTEN_TE (0x1 << 8) /* TXFIFO Empty Interrupt Enable */
97 #define SPI_INTEN_TH (0x1 << 9) /* TXFIFO Half Interrupt Enable */
98 #define SPI_INTEN_TF (0x1 << 10) /* TXFIFO Full Interrupt Enable */
99 #define SPI_INTEN_RE (0x1 << 11) /* RXFIFO Data Ready Interrupt Enable */
100 #define SPI_INTEN_RH (0x1 << 12) /* RXFIFO Half Interrupt Enable */
101 #define SPI_INTEN_RF (0x1 << 13) /* RXFIFO Full Interrupt Enable */
102 #define SPI_INTEN_RO (0x1 << 14) /* RXFIFO Overflow Interrupt Enable */
103 #define SPI_INTEN_BO (0x1 << 15) /* Bit Count Overflow Interrupt Enable */
104 #define SPI_INTEN (0xFF << 8) /* SPI Interrupt Enable Mask */
105
106 /* SPI Test Register Bit Fields & Masks */
107 #define SPI_TEST_TXCNT (0xF << 0) /* TXFIFO Counter */
108 #define SPI_TEST_RXCNT_LSB (4) /* RXFIFO Counter LSB */
109 #define SPI_TEST_RXCNT (0xF << 4) /* RXFIFO Counter */
110 #define SPI_TEST_SSTATUS (0xF << 8) /* State Machine Status */
111 #define SPI_TEST_LBC (0x1 << 14) /* Loop Back Control */
112
113 /* SPI Period Register Bit Fields & Masks */
114 #define SPI_PERIOD_WAIT (0x7FFF << 0) /* Wait Between Transactions */
115 #define SPI_PERIOD_MAX_WAIT (0x7FFF) /* Max Wait Between
116 Transactions */
117 #define SPI_PERIOD_CSRC (0x1 << 15) /* Period Clock Source Mask */
118 #define SPI_PERIOD_CSRC_BCLK (0x0 << 15) /* Period Clock Source is
119 Bit Clock */
120 #define SPI_PERIOD_CSRC_32768 (0x1 << 15) /* Period Clock Source is
121 32.768 KHz Clock */
122
123 /* SPI DMA Register Bit Fields & Masks */
124 #define SPI_DMA_RHDMA (0x1 << 4) /* RXFIFO Half Status */
125 #define SPI_DMA_RFDMA (0x1 << 5) /* RXFIFO Full Status */
126 #define SPI_DMA_TEDMA (0x1 << 6) /* TXFIFO Empty Status */
127 #define SPI_DMA_THDMA (0x1 << 7) /* TXFIFO Half Status */
128 #define SPI_DMA_RHDEN (0x1 << 12) /* RXFIFO Half DMA Request Enable */
129 #define SPI_DMA_RFDEN (0x1 << 13) /* RXFIFO Full DMA Request Enable */
130 #define SPI_DMA_TEDEN (0x1 << 14) /* TXFIFO Empty DMA Request Enable */
131 #define SPI_DMA_THDEN (0x1 << 15) /* TXFIFO Half DMA Request Enable */
132
133 /* SPI Soft Reset Register Bit Fields & Masks */
134 #define SPI_RESET_START (0x1) /* Start */
135
136 /* Default SPI configuration values */
137 #define SPI_DEFAULT_CONTROL \
138 ( \
139 SPI_CONTROL_BITCOUNT(16) | \
140 SPI_CONTROL_POL_ACT_HIGH | \
141 SPI_CONTROL_PHA_0 | \
142 SPI_CONTROL_SPIEN | \
143 SPI_CONTROL_SSCTL_1 | \
144 SPI_CONTROL_MODE_MASTER | \
145 SPI_CONTROL_DRCTL_0 | \
146 SPI_CONTROL_DATARATE_MIN \
147 )
148 #define SPI_DEFAULT_ENABLE_LOOPBACK (0)
149 #define SPI_DEFAULT_ENABLE_DMA (0)
150 #define SPI_DEFAULT_PERIOD_WAIT (8)
151 /*-------------------------------------------------------------------------*/
152
153
154 /*-------------------------------------------------------------------------*/
155 /* TX/RX SPI FIFO size */
156 #define SPI_FIFO_DEPTH (8)
157 #define SPI_FIFO_BYTE_WIDTH (2)
158 #define SPI_FIFO_OVERFLOW_MARGIN (2)
159
160 /* DMA burst lenght for half full/empty request trigger */
161 #define SPI_DMA_BLR (SPI_FIFO_DEPTH * SPI_FIFO_BYTE_WIDTH / 2)
162
163 /* Dummy char output to achieve reads.
164 Choosing something different from all zeroes may help pattern recogition
165 for oscilloscope analysis, but may break some drivers. */
166 #define SPI_DUMMY_u8 0
167 #define SPI_DUMMY_u16 ((SPI_DUMMY_u8 << 8) | SPI_DUMMY_u8)
168 #define SPI_DUMMY_u32 ((SPI_DUMMY_u16 << 16) | SPI_DUMMY_u16)
169
170 /**
171 * Macro to change a u32 field:
172 * @r : register to edit
173 * @m : bit mask
174 * @v : new value for the field correctly bit-alligned
175 */
176 #define u32_EDIT(r, m, v) r = (r & ~(m)) | (v)
177
178 /* Message state */
179 #define START_STATE ((void*)0)
180 #define RUNNING_STATE ((void*)1)
181 #define DONE_STATE ((void*)2)
182 #define ERROR_STATE ((void*)-1)
183
184 /* Queue state */
185 #define QUEUE_RUNNING (0)
186 #define QUEUE_STOPPED (1)
187
188 #define IS_DMA_ALIGNED(x) (((u32)(x) & 0x03) == 0)
189 /*-------------------------------------------------------------------------*/
190
191
192 /*-------------------------------------------------------------------------*/
193 /* Driver data structs */
194
195 /* Context */
196 struct driver_data {
197 /* Driver model hookup */
198 struct platform_device *pdev;
199
200 /* SPI framework hookup */
201 struct spi_master *master;
202
203 /* IMX hookup */
204 struct spi_imx_master *master_info;
205
206 /* Memory resources and SPI regs virtual address */
207 struct resource *ioarea;
208 void __iomem *regs;
209
210 /* SPI RX_DATA physical address */
211 dma_addr_t rd_data_phys;
212
213 /* Driver message queue */
214 struct workqueue_struct *workqueue;
215 struct work_struct work;
216 spinlock_t lock;
217 struct list_head queue;
218 int busy;
219 int run;
220
221 /* Message Transfer pump */
222 struct tasklet_struct pump_transfers;
223
224 /* Current message, transfer and state */
225 struct spi_message *cur_msg;
226 struct spi_transfer *cur_transfer;
227 struct chip_data *cur_chip;
228
229 /* Rd / Wr buffers pointers */
230 size_t len;
231 void *tx;
232 void *tx_end;
233 void *rx;
234 void *rx_end;
235
236 u8 rd_only;
237 u8 n_bytes;
238 int cs_change;
239
240 /* Function pointers */
241 irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
242 void (*cs_control)(u32 command);
243
244 /* DMA setup */
245 int rx_channel;
246 int tx_channel;
247 dma_addr_t rx_dma;
248 dma_addr_t tx_dma;
249 int rx_dma_needs_unmap;
250 int tx_dma_needs_unmap;
251 size_t tx_map_len;
252 u32 dummy_dma_buf ____cacheline_aligned;
253 };
254
255 /* Runtime state */
256 struct chip_data {
257 u32 control;
258 u32 period;
259 u32 test;
260
261 u8 enable_dma:1;
262 u8 bits_per_word;
263 u8 n_bytes;
264 u32 max_speed_hz;
265
266 void (*cs_control)(u32 command);
267 };
268 /*-------------------------------------------------------------------------*/
269
270
271 static void pump_messages(struct work_struct *work);
272
273 static int flush(struct driver_data *drv_data)
274 {
275 unsigned long limit = loops_per_jiffy << 1;
276 void __iomem *regs = drv_data->regs;
277 volatile u32 d;
278
279 dev_dbg(&drv_data->pdev->dev, "flush\n");
280 do {
281 while (readl(regs + SPI_INT_STATUS) & SPI_STATUS_RR)
282 d = readl(regs + SPI_RXDATA);
283 } while ((readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH) && limit--);
284
285 return limit;
286 }
287
288 static void restore_state(struct driver_data *drv_data)
289 {
290 void __iomem *regs = drv_data->regs;
291 struct chip_data *chip = drv_data->cur_chip;
292
293 /* Load chip registers */
294 dev_dbg(&drv_data->pdev->dev,
295 "restore_state\n"
296 " test = 0x%08X\n"
297 " control = 0x%08X\n",
298 chip->test,
299 chip->control);
300 writel(chip->test, regs + SPI_TEST);
301 writel(chip->period, regs + SPI_PERIOD);
302 writel(0, regs + SPI_INT_STATUS);
303 writel(chip->control, regs + SPI_CONTROL);
304 }
305
306 static void null_cs_control(u32 command)
307 {
308 }
309
310 static inline u32 data_to_write(struct driver_data *drv_data)
311 {
312 return ((u32)(drv_data->tx_end - drv_data->tx)) / drv_data->n_bytes;
313 }
314
315 static inline u32 data_to_read(struct driver_data *drv_data)
316 {
317 return ((u32)(drv_data->rx_end - drv_data->rx)) / drv_data->n_bytes;
318 }
319
320 static int write(struct driver_data *drv_data)
321 {
322 void __iomem *regs = drv_data->regs;
323 void *tx = drv_data->tx;
324 void *tx_end = drv_data->tx_end;
325 u8 n_bytes = drv_data->n_bytes;
326 u32 remaining_writes;
327 u32 fifo_avail_space;
328 u32 n;
329 u16 d;
330
331 /* Compute how many fifo writes to do */
332 remaining_writes = (u32)(tx_end - tx) / n_bytes;
333 fifo_avail_space = SPI_FIFO_DEPTH -
334 (readl(regs + SPI_TEST) & SPI_TEST_TXCNT);
335 if (drv_data->rx && (fifo_avail_space > SPI_FIFO_OVERFLOW_MARGIN))
336 /* Fix misunderstood receive overflow */
337 fifo_avail_space -= SPI_FIFO_OVERFLOW_MARGIN;
338 n = min(remaining_writes, fifo_avail_space);
339
340 dev_dbg(&drv_data->pdev->dev,
341 "write type %s\n"
342 " remaining writes = %d\n"
343 " fifo avail space = %d\n"
344 " fifo writes = %d\n",
345 (n_bytes == 1) ? "u8" : "u16",
346 remaining_writes,
347 fifo_avail_space,
348 n);
349
350 if (n > 0) {
351 /* Fill SPI TXFIFO */
352 if (drv_data->rd_only) {
353 tx += n * n_bytes;
354 while (n--)
355 writel(SPI_DUMMY_u16, regs + SPI_TXDATA);
356 } else {
357 if (n_bytes == 1) {
358 while (n--) {
359 d = *(u8*)tx;
360 writel(d, regs + SPI_TXDATA);
361 tx += 1;
362 }
363 } else {
364 while (n--) {
365 d = *(u16*)tx;
366 writel(d, regs + SPI_TXDATA);
367 tx += 2;
368 }
369 }
370 }
371
372 /* Trigger transfer */
373 writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
374 regs + SPI_CONTROL);
375
376 /* Update tx pointer */
377 drv_data->tx = tx;
378 }
379
380 return (tx >= tx_end);
381 }
382
383 static int read(struct driver_data *drv_data)
384 {
385 void __iomem *regs = drv_data->regs;
386 void *rx = drv_data->rx;
387 void *rx_end = drv_data->rx_end;
388 u8 n_bytes = drv_data->n_bytes;
389 u32 remaining_reads;
390 u32 fifo_rxcnt;
391 u32 n;
392 u16 d;
393
394 /* Compute how many fifo reads to do */
395 remaining_reads = (u32)(rx_end - rx) / n_bytes;
396 fifo_rxcnt = (readl(regs + SPI_TEST) & SPI_TEST_RXCNT) >>
397 SPI_TEST_RXCNT_LSB;
398 n = min(remaining_reads, fifo_rxcnt);
399
400 dev_dbg(&drv_data->pdev->dev,
401 "read type %s\n"
402 " remaining reads = %d\n"
403 " fifo rx count = %d\n"
404 " fifo reads = %d\n",
405 (n_bytes == 1) ? "u8" : "u16",
406 remaining_reads,
407 fifo_rxcnt,
408 n);
409
410 if (n > 0) {
411 /* Read SPI RXFIFO */
412 if (n_bytes == 1) {
413 while (n--) {
414 d = readl(regs + SPI_RXDATA);
415 *((u8*)rx) = d;
416 rx += 1;
417 }
418 } else {
419 while (n--) {
420 d = readl(regs + SPI_RXDATA);
421 *((u16*)rx) = d;
422 rx += 2;
423 }
424 }
425
426 /* Update rx pointer */
427 drv_data->rx = rx;
428 }
429
430 return (rx >= rx_end);
431 }
432
433 static void *next_transfer(struct driver_data *drv_data)
434 {
435 struct spi_message *msg = drv_data->cur_msg;
436 struct spi_transfer *trans = drv_data->cur_transfer;
437
438 /* Move to next transfer */
439 if (trans->transfer_list.next != &msg->transfers) {
440 drv_data->cur_transfer =
441 list_entry(trans->transfer_list.next,
442 struct spi_transfer,
443 transfer_list);
444 return RUNNING_STATE;
445 }
446
447 return DONE_STATE;
448 }
449
450 static int map_dma_buffers(struct driver_data *drv_data)
451 {
452 struct spi_message *msg;
453 struct device *dev;
454 void *buf;
455
456 drv_data->rx_dma_needs_unmap = 0;
457 drv_data->tx_dma_needs_unmap = 0;
458
459 if (!drv_data->master_info->enable_dma ||
460 !drv_data->cur_chip->enable_dma)
461 return -1;
462
463 msg = drv_data->cur_msg;
464 dev = &msg->spi->dev;
465 if (msg->is_dma_mapped) {
466 if (drv_data->tx_dma)
467 /* The caller provided at least dma and cpu virtual
468 address for write; pump_transfers() will consider the
469 transfer as write only if cpu rx virtual address is
470 NULL */
471 return 0;
472
473 if (drv_data->rx_dma) {
474 /* The caller provided dma and cpu virtual address to
475 performe read only transfer -->
476 use drv_data->dummy_dma_buf for dummy writes to
477 achive reads */
478 buf = &drv_data->dummy_dma_buf;
479 drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
480 drv_data->tx_dma = dma_map_single(dev,
481 buf,
482 drv_data->tx_map_len,
483 DMA_TO_DEVICE);
484 if (dma_mapping_error(drv_data->tx_dma))
485 return -1;
486
487 drv_data->tx_dma_needs_unmap = 1;
488
489 /* Flags transfer as rd_only for pump_transfers() DMA
490 regs programming (should be redundant) */
491 drv_data->tx = NULL;
492
493 return 0;
494 }
495 }
496
497 if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx))
498 return -1;
499
500 /* NULL rx means write-only transfer and no map needed
501 since rx DMA will not be used */
502 if (drv_data->rx) {
503 buf = drv_data->rx;
504 drv_data->rx_dma = dma_map_single(
505 dev,
506 buf,
507 drv_data->len,
508 DMA_FROM_DEVICE);
509 if (dma_mapping_error(drv_data->rx_dma))
510 return -1;
511 drv_data->rx_dma_needs_unmap = 1;
512 }
513
514 if (drv_data->tx == NULL) {
515 /* Read only message --> use drv_data->dummy_dma_buf for dummy
516 writes to achive reads */
517 buf = &drv_data->dummy_dma_buf;
518 drv_data->tx_map_len = sizeof(drv_data->dummy_dma_buf);
519 } else {
520 buf = drv_data->tx;
521 drv_data->tx_map_len = drv_data->len;
522 }
523 drv_data->tx_dma = dma_map_single(dev,
524 buf,
525 drv_data->tx_map_len,
526 DMA_TO_DEVICE);
527 if (dma_mapping_error(drv_data->tx_dma)) {
528 if (drv_data->rx_dma) {
529 dma_unmap_single(dev,
530 drv_data->rx_dma,
531 drv_data->len,
532 DMA_FROM_DEVICE);
533 drv_data->rx_dma_needs_unmap = 0;
534 }
535 return -1;
536 }
537 drv_data->tx_dma_needs_unmap = 1;
538
539 return 0;
540 }
541
542 static void unmap_dma_buffers(struct driver_data *drv_data)
543 {
544 struct spi_message *msg = drv_data->cur_msg;
545 struct device *dev = &msg->spi->dev;
546
547 if (drv_data->rx_dma_needs_unmap) {
548 dma_unmap_single(dev,
549 drv_data->rx_dma,
550 drv_data->len,
551 DMA_FROM_DEVICE);
552 drv_data->rx_dma_needs_unmap = 0;
553 }
554 if (drv_data->tx_dma_needs_unmap) {
555 dma_unmap_single(dev,
556 drv_data->tx_dma,
557 drv_data->tx_map_len,
558 DMA_TO_DEVICE);
559 drv_data->tx_dma_needs_unmap = 0;
560 }
561 }
562
563 /* Caller already set message->status (dma is already blocked) */
564 static void giveback(struct spi_message *message, struct driver_data *drv_data)
565 {
566 void __iomem *regs = drv_data->regs;
567
568 /* Bring SPI to sleep; restore_state() and pump_transfer()
569 will do new setup */
570 writel(0, regs + SPI_INT_STATUS);
571 writel(0, regs + SPI_DMA);
572
573 drv_data->cs_control(SPI_CS_DEASSERT);
574
575 message->state = NULL;
576 if (message->complete)
577 message->complete(message->context);
578
579 drv_data->cur_msg = NULL;
580 drv_data->cur_transfer = NULL;
581 drv_data->cur_chip = NULL;
582 queue_work(drv_data->workqueue, &drv_data->work);
583 }
584
585 static void dma_err_handler(int channel, void *data, int errcode)
586 {
587 struct driver_data *drv_data = data;
588 struct spi_message *msg = drv_data->cur_msg;
589
590 dev_dbg(&drv_data->pdev->dev, "dma_err_handler\n");
591
592 /* Disable both rx and tx dma channels */
593 imx_dma_disable(drv_data->rx_channel);
594 imx_dma_disable(drv_data->tx_channel);
595
596 if (flush(drv_data) == 0)
597 dev_err(&drv_data->pdev->dev,
598 "dma_err_handler - flush failed\n");
599
600 unmap_dma_buffers(drv_data);
601
602 msg->state = ERROR_STATE;
603 tasklet_schedule(&drv_data->pump_transfers);
604 }
605
606 static void dma_tx_handler(int channel, void *data)
607 {
608 struct driver_data *drv_data = data;
609
610 dev_dbg(&drv_data->pdev->dev, "dma_tx_handler\n");
611
612 imx_dma_disable(channel);
613
614 /* Now waits for TX FIFO empty */
615 writel(readl(drv_data->regs + SPI_INT_STATUS) | SPI_INTEN_TE,
616 drv_data->regs + SPI_INT_STATUS);
617 }
618
619 static irqreturn_t dma_transfer(struct driver_data *drv_data)
620 {
621 u32 status;
622 struct spi_message *msg = drv_data->cur_msg;
623 void __iomem *regs = drv_data->regs;
624 unsigned long limit;
625
626 status = readl(regs + SPI_INT_STATUS);
627
628 if ((status & SPI_INTEN_RO) && (status & SPI_STATUS_RO)) {
629 writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
630
631 imx_dma_disable(drv_data->rx_channel);
632 unmap_dma_buffers(drv_data);
633
634 if (flush(drv_data) == 0)
635 dev_err(&drv_data->pdev->dev,
636 "dma_transfer - flush failed\n");
637
638 dev_warn(&drv_data->pdev->dev,
639 "dma_transfer - fifo overun\n");
640
641 msg->state = ERROR_STATE;
642 tasklet_schedule(&drv_data->pump_transfers);
643
644 return IRQ_HANDLED;
645 }
646
647 if (status & SPI_STATUS_TE) {
648 writel(status & ~SPI_INTEN_TE, regs + SPI_INT_STATUS);
649
650 if (drv_data->rx) {
651 /* Wait end of transfer before read trailing data */
652 limit = loops_per_jiffy << 1;
653 while ((readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH) &&
654 limit--);
655
656 if (limit == 0)
657 dev_err(&drv_data->pdev->dev,
658 "dma_transfer - end of tx failed\n");
659 else
660 dev_dbg(&drv_data->pdev->dev,
661 "dma_transfer - end of tx\n");
662
663 imx_dma_disable(drv_data->rx_channel);
664 unmap_dma_buffers(drv_data);
665
666 /* Calculate number of trailing data and read them */
667 dev_dbg(&drv_data->pdev->dev,
668 "dma_transfer - test = 0x%08X\n",
669 readl(regs + SPI_TEST));
670 drv_data->rx = drv_data->rx_end -
671 ((readl(regs + SPI_TEST) &
672 SPI_TEST_RXCNT) >>
673 SPI_TEST_RXCNT_LSB)*drv_data->n_bytes;
674 read(drv_data);
675 } else {
676 /* Write only transfer */
677 unmap_dma_buffers(drv_data);
678
679 if (flush(drv_data) == 0)
680 dev_err(&drv_data->pdev->dev,
681 "dma_transfer - flush failed\n");
682 }
683
684 /* End of transfer, update total byte transfered */
685 msg->actual_length += drv_data->len;
686
687 /* Release chip select if requested, transfer delays are
688 handled in pump_transfers() */
689 if (drv_data->cs_change)
690 drv_data->cs_control(SPI_CS_DEASSERT);
691
692 /* Move to next transfer */
693 msg->state = next_transfer(drv_data);
694
695 /* Schedule transfer tasklet */
696 tasklet_schedule(&drv_data->pump_transfers);
697
698 return IRQ_HANDLED;
699 }
700
701 /* Opps problem detected */
702 return IRQ_NONE;
703 }
704
705 static irqreturn_t interrupt_wronly_transfer(struct driver_data *drv_data)
706 {
707 struct spi_message *msg = drv_data->cur_msg;
708 void __iomem *regs = drv_data->regs;
709 u32 status;
710 irqreturn_t handled = IRQ_NONE;
711
712 status = readl(regs + SPI_INT_STATUS);
713
714 while (status & SPI_STATUS_TH) {
715 dev_dbg(&drv_data->pdev->dev,
716 "interrupt_wronly_transfer - status = 0x%08X\n", status);
717
718 /* Pump data */
719 if (write(drv_data)) {
720 writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
721 regs + SPI_INT_STATUS);
722
723 dev_dbg(&drv_data->pdev->dev,
724 "interrupt_wronly_transfer - end of tx\n");
725
726 if (flush(drv_data) == 0)
727 dev_err(&drv_data->pdev->dev,
728 "interrupt_wronly_transfer - "
729 "flush failed\n");
730
731 /* End of transfer, update total byte transfered */
732 msg->actual_length += drv_data->len;
733
734 /* Release chip select if requested, transfer delays are
735 handled in pump_transfers */
736 if (drv_data->cs_change)
737 drv_data->cs_control(SPI_CS_DEASSERT);
738
739 /* Move to next transfer */
740 msg->state = next_transfer(drv_data);
741
742 /* Schedule transfer tasklet */
743 tasklet_schedule(&drv_data->pump_transfers);
744
745 return IRQ_HANDLED;
746 }
747
748 status = readl(regs + SPI_INT_STATUS);
749
750 /* We did something */
751 handled = IRQ_HANDLED;
752 }
753
754 return handled;
755 }
756
757 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
758 {
759 struct spi_message *msg = drv_data->cur_msg;
760 void __iomem *regs = drv_data->regs;
761 u32 status;
762 irqreturn_t handled = IRQ_NONE;
763 unsigned long limit;
764
765 status = readl(regs + SPI_INT_STATUS);
766
767 while (status & (SPI_STATUS_TH | SPI_STATUS_RO)) {
768 dev_dbg(&drv_data->pdev->dev,
769 "interrupt_transfer - status = 0x%08X\n", status);
770
771 if (status & SPI_STATUS_RO) {
772 writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
773 regs + SPI_INT_STATUS);
774
775 dev_warn(&drv_data->pdev->dev,
776 "interrupt_transfer - fifo overun\n"
777 " data not yet written = %d\n"
778 " data not yet read = %d\n",
779 data_to_write(drv_data),
780 data_to_read(drv_data));
781
782 if (flush(drv_data) == 0)
783 dev_err(&drv_data->pdev->dev,
784 "interrupt_transfer - flush failed\n");
785
786 msg->state = ERROR_STATE;
787 tasklet_schedule(&drv_data->pump_transfers);
788
789 return IRQ_HANDLED;
790 }
791
792 /* Pump data */
793 read(drv_data);
794 if (write(drv_data)) {
795 writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
796 regs + SPI_INT_STATUS);
797
798 dev_dbg(&drv_data->pdev->dev,
799 "interrupt_transfer - end of tx\n");
800
801 /* Read trailing bytes */
802 limit = loops_per_jiffy << 1;
803 while ((read(drv_data) == 0) && limit--);
804
805 if (limit == 0)
806 dev_err(&drv_data->pdev->dev,
807 "interrupt_transfer - "
808 "trailing byte read failed\n");
809 else
810 dev_dbg(&drv_data->pdev->dev,
811 "interrupt_transfer - end of rx\n");
812
813 /* End of transfer, update total byte transfered */
814 msg->actual_length += drv_data->len;
815
816 /* Release chip select if requested, transfer delays are
817 handled in pump_transfers */
818 if (drv_data->cs_change)
819 drv_data->cs_control(SPI_CS_DEASSERT);
820
821 /* Move to next transfer */
822 msg->state = next_transfer(drv_data);
823
824 /* Schedule transfer tasklet */
825 tasklet_schedule(&drv_data->pump_transfers);
826
827 return IRQ_HANDLED;
828 }
829
830 status = readl(regs + SPI_INT_STATUS);
831
832 /* We did something */
833 handled = IRQ_HANDLED;
834 }
835
836 return handled;
837 }
838
839 static irqreturn_t spi_int(int irq, void *dev_id)
840 {
841 struct driver_data *drv_data = (struct driver_data *)dev_id;
842
843 if (!drv_data->cur_msg) {
844 dev_err(&drv_data->pdev->dev,
845 "spi_int - bad message state\n");
846 /* Never fail */
847 return IRQ_HANDLED;
848 }
849
850 return drv_data->transfer_handler(drv_data);
851 }
852
853 static inline u32 spi_speed_hz(u32 data_rate)
854 {
855 return imx_get_perclk2() / (4 << ((data_rate) >> 13));
856 }
857
858 static u32 spi_data_rate(u32 speed_hz)
859 {
860 u32 div;
861 u32 quantized_hz = imx_get_perclk2() >> 2;
862
863 for (div = SPI_PERCLK2_DIV_MIN;
864 div <= SPI_PERCLK2_DIV_MAX;
865 div++, quantized_hz >>= 1) {
866 if (quantized_hz <= speed_hz)
867 /* Max available speed LEQ required speed */
868 return div << 13;
869 }
870 return SPI_CONTROL_DATARATE_BAD;
871 }
872
873 static void pump_transfers(unsigned long data)
874 {
875 struct driver_data *drv_data = (struct driver_data *)data;
876 struct spi_message *message;
877 struct spi_transfer *transfer, *previous;
878 struct chip_data *chip;
879 void __iomem *regs;
880 u32 tmp, control;
881
882 dev_dbg(&drv_data->pdev->dev, "pump_transfer\n");
883
884 message = drv_data->cur_msg;
885
886 /* Handle for abort */
887 if (message->state == ERROR_STATE) {
888 message->status = -EIO;
889 giveback(message, drv_data);
890 return;
891 }
892
893 /* Handle end of message */
894 if (message->state == DONE_STATE) {
895 message->status = 0;
896 giveback(message, drv_data);
897 return;
898 }
899
900 chip = drv_data->cur_chip;
901
902 /* Delay if requested at end of transfer*/
903 transfer = drv_data->cur_transfer;
904 if (message->state == RUNNING_STATE) {
905 previous = list_entry(transfer->transfer_list.prev,
906 struct spi_transfer,
907 transfer_list);
908 if (previous->delay_usecs)
909 udelay(previous->delay_usecs);
910 } else {
911 /* START_STATE */
912 message->state = RUNNING_STATE;
913 drv_data->cs_control = chip->cs_control;
914 }
915
916 transfer = drv_data->cur_transfer;
917 drv_data->tx = (void *)transfer->tx_buf;
918 drv_data->tx_end = drv_data->tx + transfer->len;
919 drv_data->rx = transfer->rx_buf;
920 drv_data->rx_end = drv_data->rx + transfer->len;
921 drv_data->rx_dma = transfer->rx_dma;
922 drv_data->tx_dma = transfer->tx_dma;
923 drv_data->len = transfer->len;
924 drv_data->cs_change = transfer->cs_change;
925 drv_data->rd_only = (drv_data->tx == NULL);
926
927 regs = drv_data->regs;
928 control = readl(regs + SPI_CONTROL);
929
930 /* Bits per word setup */
931 tmp = transfer->bits_per_word;
932 if (tmp == 0) {
933 /* Use device setup */
934 tmp = chip->bits_per_word;
935 drv_data->n_bytes = chip->n_bytes;
936 } else
937 /* Use per-transfer setup */
938 drv_data->n_bytes = (tmp <= 8) ? 1 : 2;
939 u32_EDIT(control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
940
941 /* Speed setup (surely valid because already checked) */
942 tmp = transfer->speed_hz;
943 if (tmp == 0)
944 tmp = chip->max_speed_hz;
945 tmp = spi_data_rate(tmp);
946 u32_EDIT(control, SPI_CONTROL_DATARATE, tmp);
947
948 writel(control, regs + SPI_CONTROL);
949
950 /* Assert device chip-select */
951 drv_data->cs_control(SPI_CS_ASSERT);
952
953 /* DMA cannot read/write SPI FIFOs other than 16 bits at a time; hence
954 if bits_per_word is less or equal 8 PIO transfers are performed.
955 Moreover DMA is convinient for transfer length bigger than FIFOs
956 byte size. */
957 if ((drv_data->n_bytes == 2) &&
958 (drv_data->len > SPI_FIFO_DEPTH*SPI_FIFO_BYTE_WIDTH) &&
959 (map_dma_buffers(drv_data) == 0)) {
960 dev_dbg(&drv_data->pdev->dev,
961 "pump dma transfer\n"
962 " tx = %p\n"
963 " tx_dma = %08X\n"
964 " rx = %p\n"
965 " rx_dma = %08X\n"
966 " len = %d\n",
967 drv_data->tx,
968 (unsigned int)drv_data->tx_dma,
969 drv_data->rx,
970 (unsigned int)drv_data->rx_dma,
971 drv_data->len);
972
973 /* Ensure we have the correct interrupt handler */
974 drv_data->transfer_handler = dma_transfer;
975
976 /* Trigger transfer */
977 writel(readl(regs + SPI_CONTROL) | SPI_CONTROL_XCH,
978 regs + SPI_CONTROL);
979
980 /* Setup tx DMA */
981 if (drv_data->tx)
982 /* Linear source address */
983 CCR(drv_data->tx_channel) =
984 CCR_DMOD_FIFO |
985 CCR_SMOD_LINEAR |
986 CCR_SSIZ_32 | CCR_DSIZ_16 |
987 CCR_REN;
988 else
989 /* Read only transfer -> fixed source address for
990 dummy write to achive read */
991 CCR(drv_data->tx_channel) =
992 CCR_DMOD_FIFO |
993 CCR_SMOD_FIFO |
994 CCR_SSIZ_32 | CCR_DSIZ_16 |
995 CCR_REN;
996
997 imx_dma_setup_single(
998 drv_data->tx_channel,
999 drv_data->tx_dma,
1000 drv_data->len,
1001 drv_data->rd_data_phys + 4,
1002 DMA_MODE_WRITE);
1003
1004 if (drv_data->rx) {
1005 /* Setup rx DMA for linear destination address */
1006 CCR(drv_data->rx_channel) =
1007 CCR_DMOD_LINEAR |
1008 CCR_SMOD_FIFO |
1009 CCR_DSIZ_32 | CCR_SSIZ_16 |
1010 CCR_REN;
1011 imx_dma_setup_single(
1012 drv_data->rx_channel,
1013 drv_data->rx_dma,
1014 drv_data->len,
1015 drv_data->rd_data_phys,
1016 DMA_MODE_READ);
1017 imx_dma_enable(drv_data->rx_channel);
1018
1019 /* Enable SPI interrupt */
1020 writel(SPI_INTEN_RO, regs + SPI_INT_STATUS);
1021
1022 /* Set SPI to request DMA service on both
1023 Rx and Tx half fifo watermark */
1024 writel(SPI_DMA_RHDEN | SPI_DMA_THDEN, regs + SPI_DMA);
1025 } else
1026 /* Write only access -> set SPI to request DMA
1027 service on Tx half fifo watermark */
1028 writel(SPI_DMA_THDEN, regs + SPI_DMA);
1029
1030 imx_dma_enable(drv_data->tx_channel);
1031 } else {
1032 dev_dbg(&drv_data->pdev->dev,
1033 "pump pio transfer\n"
1034 " tx = %p\n"
1035 " rx = %p\n"
1036 " len = %d\n",
1037 drv_data->tx,
1038 drv_data->rx,
1039 drv_data->len);
1040
1041 /* Ensure we have the correct interrupt handler */
1042 if (drv_data->rx)
1043 drv_data->transfer_handler = interrupt_transfer;
1044 else
1045 drv_data->transfer_handler = interrupt_wronly_transfer;
1046
1047 /* Enable SPI interrupt */
1048 if (drv_data->rx)
1049 writel(SPI_INTEN_TH | SPI_INTEN_RO,
1050 regs + SPI_INT_STATUS);
1051 else
1052 writel(SPI_INTEN_TH, regs + SPI_INT_STATUS);
1053 }
1054 }
1055
1056 static void pump_messages(struct work_struct *work)
1057 {
1058 struct driver_data *drv_data =
1059 container_of(work, struct driver_data, work);
1060 unsigned long flags;
1061
1062 /* Lock queue and check for queue work */
1063 spin_lock_irqsave(&drv_data->lock, flags);
1064 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
1065 drv_data->busy = 0;
1066 spin_unlock_irqrestore(&drv_data->lock, flags);
1067 return;
1068 }
1069
1070 /* Make sure we are not already running a message */
1071 if (drv_data->cur_msg) {
1072 spin_unlock_irqrestore(&drv_data->lock, flags);
1073 return;
1074 }
1075
1076 /* Extract head of queue */
1077 drv_data->cur_msg = list_entry(drv_data->queue.next,
1078 struct spi_message, queue);
1079 list_del_init(&drv_data->cur_msg->queue);
1080 drv_data->busy = 1;
1081 spin_unlock_irqrestore(&drv_data->lock, flags);
1082
1083 /* Initial message state */
1084 drv_data->cur_msg->state = START_STATE;
1085 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
1086 struct spi_transfer,
1087 transfer_list);
1088
1089 /* Setup the SPI using the per chip configuration */
1090 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
1091 restore_state(drv_data);
1092
1093 /* Mark as busy and launch transfers */
1094 tasklet_schedule(&drv_data->pump_transfers);
1095 }
1096
1097 static int transfer(struct spi_device *spi, struct spi_message *msg)
1098 {
1099 struct driver_data *drv_data = spi_master_get_devdata(spi->master);
1100 u32 min_speed_hz, max_speed_hz, tmp;
1101 struct spi_transfer *trans;
1102 unsigned long flags;
1103
1104 msg->actual_length = 0;
1105
1106 /* Per transfer setup check */
1107 min_speed_hz = spi_speed_hz(SPI_CONTROL_DATARATE_MIN);
1108 max_speed_hz = spi->max_speed_hz;
1109 list_for_each_entry(trans, &msg->transfers, transfer_list) {
1110 tmp = trans->bits_per_word;
1111 if (tmp > 16) {
1112 dev_err(&drv_data->pdev->dev,
1113 "message rejected : "
1114 "invalid transfer bits_per_word (%d bits)\n",
1115 tmp);
1116 goto msg_rejected;
1117 }
1118 tmp = trans->speed_hz;
1119 if (tmp) {
1120 if (tmp < min_speed_hz) {
1121 dev_err(&drv_data->pdev->dev,
1122 "message rejected : "
1123 "device min speed (%d Hz) exceeds "
1124 "required transfer speed (%d Hz)\n",
1125 min_speed_hz,
1126 tmp);
1127 goto msg_rejected;
1128 } else if (tmp > max_speed_hz) {
1129 dev_err(&drv_data->pdev->dev,
1130 "message rejected : "
1131 "transfer speed (%d Hz) exceeds "
1132 "device max speed (%d Hz)\n",
1133 tmp,
1134 max_speed_hz);
1135 goto msg_rejected;
1136 }
1137 }
1138 }
1139
1140 /* Message accepted */
1141 msg->status = -EINPROGRESS;
1142 msg->state = START_STATE;
1143
1144 spin_lock_irqsave(&drv_data->lock, flags);
1145 if (drv_data->run == QUEUE_STOPPED) {
1146 spin_unlock_irqrestore(&drv_data->lock, flags);
1147 return -ESHUTDOWN;
1148 }
1149
1150 list_add_tail(&msg->queue, &drv_data->queue);
1151 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
1152 queue_work(drv_data->workqueue, &drv_data->work);
1153
1154 spin_unlock_irqrestore(&drv_data->lock, flags);
1155 return 0;
1156
1157 msg_rejected:
1158 /* Message rejected and not queued */
1159 msg->status = -EINVAL;
1160 msg->state = ERROR_STATE;
1161 if (msg->complete)
1162 msg->complete(msg->context);
1163 return -EINVAL;
1164 }
1165
1166 /* the spi->mode bits understood by this driver: */
1167 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
1168
1169 /* On first setup bad values must free chip_data memory since will cause
1170 spi_new_device to fail. Bad value setup from protocol driver are simply not
1171 applied and notified to the calling driver. */
1172 static int setup(struct spi_device *spi)
1173 {
1174 struct spi_imx_chip *chip_info;
1175 struct chip_data *chip;
1176 int first_setup = 0;
1177 u32 tmp;
1178 int status = 0;
1179
1180 if (spi->mode & ~MODEBITS) {
1181 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
1182 spi->mode & ~MODEBITS);
1183 return -EINVAL;
1184 }
1185
1186 /* Get controller data */
1187 chip_info = spi->controller_data;
1188
1189 /* Get controller_state */
1190 chip = spi_get_ctldata(spi);
1191 if (chip == NULL) {
1192 first_setup = 1;
1193
1194 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1195 if (!chip) {
1196 dev_err(&spi->dev,
1197 "setup - cannot allocate controller state");
1198 return -ENOMEM;
1199 }
1200 chip->control = SPI_DEFAULT_CONTROL;
1201
1202 if (chip_info == NULL) {
1203 /* spi_board_info.controller_data not is supplied */
1204 chip_info = kzalloc(sizeof(struct spi_imx_chip),
1205 GFP_KERNEL);
1206 if (!chip_info) {
1207 dev_err(&spi->dev,
1208 "setup - "
1209 "cannot allocate controller data");
1210 status = -ENOMEM;
1211 goto err_first_setup;
1212 }
1213 /* Set controller data default value */
1214 chip_info->enable_loopback =
1215 SPI_DEFAULT_ENABLE_LOOPBACK;
1216 chip_info->enable_dma = SPI_DEFAULT_ENABLE_DMA;
1217 chip_info->ins_ss_pulse = 1;
1218 chip_info->bclk_wait = SPI_DEFAULT_PERIOD_WAIT;
1219 chip_info->cs_control = null_cs_control;
1220 }
1221 }
1222
1223 /* Now set controller state based on controller data */
1224
1225 if (first_setup) {
1226 /* SPI loopback */
1227 if (chip_info->enable_loopback)
1228 chip->test = SPI_TEST_LBC;
1229 else
1230 chip->test = 0;
1231
1232 /* SPI dma driven */
1233 chip->enable_dma = chip_info->enable_dma;
1234
1235 /* SPI /SS pulse between spi burst */
1236 if (chip_info->ins_ss_pulse)
1237 u32_EDIT(chip->control,
1238 SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_1);
1239 else
1240 u32_EDIT(chip->control,
1241 SPI_CONTROL_SSCTL, SPI_CONTROL_SSCTL_0);
1242
1243 /* SPI bclk waits between each bits_per_word spi burst */
1244 if (chip_info->bclk_wait > SPI_PERIOD_MAX_WAIT) {
1245 dev_err(&spi->dev,
1246 "setup - "
1247 "bclk_wait exceeds max allowed (%d)\n",
1248 SPI_PERIOD_MAX_WAIT);
1249 goto err_first_setup;
1250 }
1251 chip->period = SPI_PERIOD_CSRC_BCLK |
1252 (chip_info->bclk_wait & SPI_PERIOD_WAIT);
1253 }
1254
1255 /* SPI mode */
1256 tmp = spi->mode;
1257 if (tmp & SPI_CS_HIGH) {
1258 u32_EDIT(chip->control,
1259 SPI_CONTROL_SSPOL, SPI_CONTROL_SSPOL_ACT_HIGH);
1260 }
1261 switch (tmp & SPI_MODE_3) {
1262 case SPI_MODE_0:
1263 tmp = 0;
1264 break;
1265 case SPI_MODE_1:
1266 tmp = SPI_CONTROL_PHA_1;
1267 break;
1268 case SPI_MODE_2:
1269 tmp = SPI_CONTROL_POL_ACT_LOW;
1270 break;
1271 default:
1272 /* SPI_MODE_3 */
1273 tmp = SPI_CONTROL_PHA_1 | SPI_CONTROL_POL_ACT_LOW;
1274 break;
1275 }
1276 u32_EDIT(chip->control, SPI_CONTROL_POL | SPI_CONTROL_PHA, tmp);
1277
1278 /* SPI word width */
1279 tmp = spi->bits_per_word;
1280 if (tmp == 0) {
1281 tmp = 8;
1282 spi->bits_per_word = 8;
1283 } else if (tmp > 16) {
1284 status = -EINVAL;
1285 dev_err(&spi->dev,
1286 "setup - "
1287 "invalid bits_per_word (%d)\n",
1288 tmp);
1289 if (first_setup)
1290 goto err_first_setup;
1291 else {
1292 /* Undo setup using chip as backup copy */
1293 tmp = chip->bits_per_word;
1294 spi->bits_per_word = tmp;
1295 }
1296 }
1297 chip->bits_per_word = tmp;
1298 u32_EDIT(chip->control, SPI_CONTROL_BITCOUNT_MASK, tmp - 1);
1299 chip->n_bytes = (tmp <= 8) ? 1 : 2;
1300
1301 /* SPI datarate */
1302 tmp = spi_data_rate(spi->max_speed_hz);
1303 if (tmp == SPI_CONTROL_DATARATE_BAD) {
1304 status = -EINVAL;
1305 dev_err(&spi->dev,
1306 "setup - "
1307 "HW min speed (%d Hz) exceeds required "
1308 "max speed (%d Hz)\n",
1309 spi_speed_hz(SPI_CONTROL_DATARATE_MIN),
1310 spi->max_speed_hz);
1311 if (first_setup)
1312 goto err_first_setup;
1313 else
1314 /* Undo setup using chip as backup copy */
1315 spi->max_speed_hz = chip->max_speed_hz;
1316 } else {
1317 u32_EDIT(chip->control, SPI_CONTROL_DATARATE, tmp);
1318 /* Actual rounded max_speed_hz */
1319 tmp = spi_speed_hz(tmp);
1320 spi->max_speed_hz = tmp;
1321 chip->max_speed_hz = tmp;
1322 }
1323
1324 /* SPI chip-select management */
1325 if (chip_info->cs_control)
1326 chip->cs_control = chip_info->cs_control;
1327 else
1328 chip->cs_control = null_cs_control;
1329
1330 /* Save controller_state */
1331 spi_set_ctldata(spi, chip);
1332
1333 /* Summary */
1334 dev_dbg(&spi->dev,
1335 "setup succeded\n"
1336 " loopback enable = %s\n"
1337 " dma enable = %s\n"
1338 " insert /ss pulse = %s\n"
1339 " period wait = %d\n"
1340 " mode = %d\n"
1341 " bits per word = %d\n"
1342 " min speed = %d Hz\n"
1343 " rounded max speed = %d Hz\n",
1344 chip->test & SPI_TEST_LBC ? "Yes" : "No",
1345 chip->enable_dma ? "Yes" : "No",
1346 chip->control & SPI_CONTROL_SSCTL ? "Yes" : "No",
1347 chip->period & SPI_PERIOD_WAIT,
1348 spi->mode,
1349 spi->bits_per_word,
1350 spi_speed_hz(SPI_CONTROL_DATARATE_MIN),
1351 spi->max_speed_hz);
1352 return status;
1353
1354 err_first_setup:
1355 kfree(chip);
1356 return status;
1357 }
1358
1359 static void cleanup(struct spi_device *spi)
1360 {
1361 kfree(spi_get_ctldata(spi));
1362 }
1363
1364 static int __init init_queue(struct driver_data *drv_data)
1365 {
1366 INIT_LIST_HEAD(&drv_data->queue);
1367 spin_lock_init(&drv_data->lock);
1368
1369 drv_data->run = QUEUE_STOPPED;
1370 drv_data->busy = 0;
1371
1372 tasklet_init(&drv_data->pump_transfers,
1373 pump_transfers, (unsigned long)drv_data);
1374
1375 INIT_WORK(&drv_data->work, pump_messages);
1376 drv_data->workqueue = create_singlethread_workqueue(
1377 drv_data->master->dev.parent->bus_id);
1378 if (drv_data->workqueue == NULL)
1379 return -EBUSY;
1380
1381 return 0;
1382 }
1383
1384 static int start_queue(struct driver_data *drv_data)
1385 {
1386 unsigned long flags;
1387
1388 spin_lock_irqsave(&drv_data->lock, flags);
1389
1390 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
1391 spin_unlock_irqrestore(&drv_data->lock, flags);
1392 return -EBUSY;
1393 }
1394
1395 drv_data->run = QUEUE_RUNNING;
1396 drv_data->cur_msg = NULL;
1397 drv_data->cur_transfer = NULL;
1398 drv_data->cur_chip = NULL;
1399 spin_unlock_irqrestore(&drv_data->lock, flags);
1400
1401 queue_work(drv_data->workqueue, &drv_data->work);
1402
1403 return 0;
1404 }
1405
1406 static int stop_queue(struct driver_data *drv_data)
1407 {
1408 unsigned long flags;
1409 unsigned limit = 500;
1410 int status = 0;
1411
1412 spin_lock_irqsave(&drv_data->lock, flags);
1413
1414 /* This is a bit lame, but is optimized for the common execution path.
1415 * A wait_queue on the drv_data->busy could be used, but then the common
1416 * execution path (pump_messages) would be required to call wake_up or
1417 * friends on every SPI message. Do this instead */
1418 drv_data->run = QUEUE_STOPPED;
1419 while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1420 spin_unlock_irqrestore(&drv_data->lock, flags);
1421 msleep(10);
1422 spin_lock_irqsave(&drv_data->lock, flags);
1423 }
1424
1425 if (!list_empty(&drv_data->queue) || drv_data->busy)
1426 status = -EBUSY;
1427
1428 spin_unlock_irqrestore(&drv_data->lock, flags);
1429
1430 return status;
1431 }
1432
1433 static int destroy_queue(struct driver_data *drv_data)
1434 {
1435 int status;
1436
1437 status = stop_queue(drv_data);
1438 if (status != 0)
1439 return status;
1440
1441 if (drv_data->workqueue)
1442 destroy_workqueue(drv_data->workqueue);
1443
1444 return 0;
1445 }
1446
1447 static int __init spi_imx_probe(struct platform_device *pdev)
1448 {
1449 struct device *dev = &pdev->dev;
1450 struct spi_imx_master *platform_info;
1451 struct spi_master *master;
1452 struct driver_data *drv_data = NULL;
1453 struct resource *res;
1454 int irq, status = 0;
1455
1456 platform_info = dev->platform_data;
1457 if (platform_info == NULL) {
1458 dev_err(&pdev->dev, "probe - no platform data supplied\n");
1459 status = -ENODEV;
1460 goto err_no_pdata;
1461 }
1462
1463 /* Allocate master with space for drv_data */
1464 master = spi_alloc_master(dev, sizeof(struct driver_data));
1465 if (!master) {
1466 dev_err(&pdev->dev, "probe - cannot alloc spi_master\n");
1467 status = -ENOMEM;
1468 goto err_no_mem;
1469 }
1470 drv_data = spi_master_get_devdata(master);
1471 drv_data->master = master;
1472 drv_data->master_info = platform_info;
1473 drv_data->pdev = pdev;
1474
1475 master->bus_num = pdev->id;
1476 master->num_chipselect = platform_info->num_chipselect;
1477 master->cleanup = cleanup;
1478 master->setup = setup;
1479 master->transfer = transfer;
1480
1481 drv_data->dummy_dma_buf = SPI_DUMMY_u32;
1482
1483 /* Find and map resources */
1484 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1485 if (!res) {
1486 dev_err(&pdev->dev, "probe - MEM resources not defined\n");
1487 status = -ENODEV;
1488 goto err_no_iores;
1489 }
1490 drv_data->ioarea = request_mem_region(res->start,
1491 res->end - res->start + 1,
1492 pdev->name);
1493 if (drv_data->ioarea == NULL) {
1494 dev_err(&pdev->dev, "probe - cannot reserve region\n");
1495 status = -ENXIO;
1496 goto err_no_iores;
1497 }
1498 drv_data->regs = ioremap(res->start, res->end - res->start + 1);
1499 if (drv_data->regs == NULL) {
1500 dev_err(&pdev->dev, "probe - cannot map IO\n");
1501 status = -ENXIO;
1502 goto err_no_iomap;
1503 }
1504 drv_data->rd_data_phys = (dma_addr_t)res->start;
1505
1506 /* Attach to IRQ */
1507 irq = platform_get_irq(pdev, 0);
1508 if (irq < 0) {
1509 dev_err(&pdev->dev, "probe - IRQ resource not defined\n");
1510 status = -ENODEV;
1511 goto err_no_irqres;
1512 }
1513 status = request_irq(irq, spi_int, IRQF_DISABLED, dev->bus_id, drv_data);
1514 if (status < 0) {
1515 dev_err(&pdev->dev, "probe - cannot get IRQ (%d)\n", status);
1516 goto err_no_irqres;
1517 }
1518
1519 /* Setup DMA if requested */
1520 drv_data->tx_channel = -1;
1521 drv_data->rx_channel = -1;
1522 if (platform_info->enable_dma) {
1523 /* Get rx DMA channel */
1524 status = imx_dma_request_by_prio(&drv_data->rx_channel,
1525 "spi_imx_rx", DMA_PRIO_HIGH);
1526 if (status < 0) {
1527 dev_err(dev,
1528 "probe - problem (%d) requesting rx channel\n",
1529 status);
1530 goto err_no_rxdma;
1531 } else
1532 imx_dma_setup_handlers(drv_data->rx_channel, NULL,
1533 dma_err_handler, drv_data);
1534
1535 /* Get tx DMA channel */
1536 status = imx_dma_request_by_prio(&drv_data->tx_channel,
1537 "spi_imx_tx", DMA_PRIO_MEDIUM);
1538 if (status < 0) {
1539 dev_err(dev,
1540 "probe - problem (%d) requesting tx channel\n",
1541 status);
1542 imx_dma_free(drv_data->rx_channel);
1543 goto err_no_txdma;
1544 } else
1545 imx_dma_setup_handlers(drv_data->tx_channel,
1546 dma_tx_handler, dma_err_handler,
1547 drv_data);
1548
1549 /* Set request source and burst length for allocated channels */
1550 switch (drv_data->pdev->id) {
1551 case 1:
1552 /* Using SPI1 */
1553 RSSR(drv_data->rx_channel) = DMA_REQ_SPI1_R;
1554 RSSR(drv_data->tx_channel) = DMA_REQ_SPI1_T;
1555 break;
1556 case 2:
1557 /* Using SPI2 */
1558 RSSR(drv_data->rx_channel) = DMA_REQ_SPI2_R;
1559 RSSR(drv_data->tx_channel) = DMA_REQ_SPI2_T;
1560 break;
1561 default:
1562 dev_err(dev, "probe - bad SPI Id\n");
1563 imx_dma_free(drv_data->rx_channel);
1564 imx_dma_free(drv_data->tx_channel);
1565 status = -ENODEV;
1566 goto err_no_devid;
1567 }
1568 BLR(drv_data->rx_channel) = SPI_DMA_BLR;
1569 BLR(drv_data->tx_channel) = SPI_DMA_BLR;
1570 }
1571
1572 /* Load default SPI configuration */
1573 writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1574 writel(0, drv_data->regs + SPI_RESET);
1575 writel(SPI_DEFAULT_CONTROL, drv_data->regs + SPI_CONTROL);
1576
1577 /* Initial and start queue */
1578 status = init_queue(drv_data);
1579 if (status != 0) {
1580 dev_err(&pdev->dev, "probe - problem initializing queue\n");
1581 goto err_init_queue;
1582 }
1583 status = start_queue(drv_data);
1584 if (status != 0) {
1585 dev_err(&pdev->dev, "probe - problem starting queue\n");
1586 goto err_start_queue;
1587 }
1588
1589 /* Register with the SPI framework */
1590 platform_set_drvdata(pdev, drv_data);
1591 status = spi_register_master(master);
1592 if (status != 0) {
1593 dev_err(&pdev->dev, "probe - problem registering spi master\n");
1594 goto err_spi_register;
1595 }
1596
1597 dev_dbg(dev, "probe succeded\n");
1598 return 0;
1599
1600 err_init_queue:
1601 err_start_queue:
1602 err_spi_register:
1603 destroy_queue(drv_data);
1604
1605 err_no_rxdma:
1606 err_no_txdma:
1607 err_no_devid:
1608 free_irq(irq, drv_data);
1609
1610 err_no_irqres:
1611 iounmap(drv_data->regs);
1612
1613 err_no_iomap:
1614 release_resource(drv_data->ioarea);
1615 kfree(drv_data->ioarea);
1616
1617 err_no_iores:
1618 spi_master_put(master);
1619
1620 err_no_pdata:
1621 err_no_mem:
1622 return status;
1623 }
1624
1625 static int __exit spi_imx_remove(struct platform_device *pdev)
1626 {
1627 struct driver_data *drv_data = platform_get_drvdata(pdev);
1628 int irq;
1629 int status = 0;
1630
1631 if (!drv_data)
1632 return 0;
1633
1634 tasklet_kill(&drv_data->pump_transfers);
1635
1636 /* Remove the queue */
1637 status = destroy_queue(drv_data);
1638 if (status != 0) {
1639 dev_err(&pdev->dev, "queue remove failed (%d)\n", status);
1640 return status;
1641 }
1642
1643 /* Reset SPI */
1644 writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1645 writel(0, drv_data->regs + SPI_RESET);
1646
1647 /* Release DMA */
1648 if (drv_data->master_info->enable_dma) {
1649 RSSR(drv_data->rx_channel) = 0;
1650 RSSR(drv_data->tx_channel) = 0;
1651 imx_dma_free(drv_data->tx_channel);
1652 imx_dma_free(drv_data->rx_channel);
1653 }
1654
1655 /* Release IRQ */
1656 irq = platform_get_irq(pdev, 0);
1657 if (irq >= 0)
1658 free_irq(irq, drv_data);
1659
1660 /* Release map resources */
1661 iounmap(drv_data->regs);
1662 release_resource(drv_data->ioarea);
1663 kfree(drv_data->ioarea);
1664
1665 /* Disconnect from the SPI framework */
1666 spi_unregister_master(drv_data->master);
1667 spi_master_put(drv_data->master);
1668
1669 /* Prevent double remove */
1670 platform_set_drvdata(pdev, NULL);
1671
1672 dev_dbg(&pdev->dev, "remove succeded\n");
1673
1674 return 0;
1675 }
1676
1677 static void spi_imx_shutdown(struct platform_device *pdev)
1678 {
1679 struct driver_data *drv_data = platform_get_drvdata(pdev);
1680
1681 /* Reset SPI */
1682 writel(SPI_RESET_START, drv_data->regs + SPI_RESET);
1683 writel(0, drv_data->regs + SPI_RESET);
1684
1685 dev_dbg(&pdev->dev, "shutdown succeded\n");
1686 }
1687
1688 #ifdef CONFIG_PM
1689 static int suspend_devices(struct device *dev, void *pm_message)
1690 {
1691 pm_message_t *state = pm_message;
1692
1693 if (dev->power.power_state.event != state->event) {
1694 dev_warn(dev, "pm state does not match request\n");
1695 return -1;
1696 }
1697
1698 return 0;
1699 }
1700
1701 static int spi_imx_suspend(struct platform_device *pdev, pm_message_t state)
1702 {
1703 struct driver_data *drv_data = platform_get_drvdata(pdev);
1704 int status = 0;
1705
1706 status = stop_queue(drv_data);
1707 if (status != 0) {
1708 dev_warn(&pdev->dev, "suspend cannot stop queue\n");
1709 return status;
1710 }
1711
1712 dev_dbg(&pdev->dev, "suspended\n");
1713
1714 return 0;
1715 }
1716
1717 static int spi_imx_resume(struct platform_device *pdev)
1718 {
1719 struct driver_data *drv_data = platform_get_drvdata(pdev);
1720 int status = 0;
1721
1722 /* Start the queue running */
1723 status = start_queue(drv_data);
1724 if (status != 0)
1725 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1726 else
1727 dev_dbg(&pdev->dev, "resumed\n");
1728
1729 return status;
1730 }
1731 #else
1732 #define spi_imx_suspend NULL
1733 #define spi_imx_resume NULL
1734 #endif /* CONFIG_PM */
1735
1736 static struct platform_driver driver = {
1737 .driver = {
1738 .name = "spi_imx",
1739 .bus = &platform_bus_type,
1740 .owner = THIS_MODULE,
1741 },
1742 .remove = __exit_p(spi_imx_remove),
1743 .shutdown = spi_imx_shutdown,
1744 .suspend = spi_imx_suspend,
1745 .resume = spi_imx_resume,
1746 };
1747
1748 static int __init spi_imx_init(void)
1749 {
1750 return platform_driver_probe(&driver, spi_imx_probe);
1751 }
1752 module_init(spi_imx_init);
1753
1754 static void __exit spi_imx_exit(void)
1755 {
1756 platform_driver_unregister(&driver);
1757 }
1758 module_exit(spi_imx_exit);
1759
1760 MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
1761 MODULE_DESCRIPTION("iMX SPI Contoller Driver");
1762 MODULE_LICENSE("GPL");
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