diff options
author | Haavard Skinnemoen <hskinnemoen@atmel.com> | 2007-02-14 03:33:09 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-14 11:09:53 -0500 |
commit | 754ce4f29937ba11f16afa41a648a30b0fc1f075 (patch) | |
tree | 65586a969cb51be1069406fd12bb441a10999b60 /drivers/spi/atmel_spi.c | |
parent | de8211b96b8491911bcb222d153c0986cb522bd6 (diff) |
[PATCH] SPI: atmel_spi driver
Driver for the Atmel on-chip SPI master controller.
Tested primarily on AVR32/AT32AP7000/ATSTK1000 using mtd_dataflash and the
jffs2 filesystem. Should also work fine on various AT91 ARM-based chips
like AT91SAM926x and AT91RM9200.
Hardware documentation can be found in the AT32AP7000 data sheet, or its
AT91 siblings, which can be downloaded from
http://www.atmel.com/dyn/products/datasheets.asp?family_id=682
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/spi/atmel_spi.c')
-rw-r--r-- | drivers/spi/atmel_spi.c | 678 |
1 files changed, 678 insertions, 0 deletions
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c new file mode 100644 index 000000000000..c2a9fef58edc --- /dev/null +++ b/drivers/spi/atmel_spi.c | |||
@@ -0,0 +1,678 @@ | |||
1 | /* | ||
2 | * Driver for Atmel AT32 and AT91 SPI Controllers | ||
3 | * | ||
4 | * Copyright (C) 2006 Atmel Corporation | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License version 2 as | ||
8 | * published by the Free Software Foundation. | ||
9 | */ | ||
10 | |||
11 | #include <linux/kernel.h> | ||
12 | #include <linux/init.h> | ||
13 | #include <linux/clk.h> | ||
14 | #include <linux/module.h> | ||
15 | #include <linux/platform_device.h> | ||
16 | #include <linux/delay.h> | ||
17 | #include <linux/dma-mapping.h> | ||
18 | #include <linux/err.h> | ||
19 | #include <linux/interrupt.h> | ||
20 | #include <linux/spi/spi.h> | ||
21 | |||
22 | #include <asm/io.h> | ||
23 | #include <asm/arch/board.h> | ||
24 | #include <asm/arch/gpio.h> | ||
25 | |||
26 | #include "atmel_spi.h" | ||
27 | |||
28 | /* | ||
29 | * The core SPI transfer engine just talks to a register bank to set up | ||
30 | * DMA transfers; transfer queue progress is driven by IRQs. The clock | ||
31 | * framework provides the base clock, subdivided for each spi_device. | ||
32 | * | ||
33 | * Newer controllers, marked with "new_1" flag, have: | ||
34 | * - CR.LASTXFER | ||
35 | * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) | ||
36 | * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) | ||
37 | * - SPI_CSRx.CSAAT | ||
38 | * - SPI_CSRx.SBCR allows faster clocking | ||
39 | */ | ||
40 | struct atmel_spi { | ||
41 | spinlock_t lock; | ||
42 | |||
43 | void __iomem *regs; | ||
44 | int irq; | ||
45 | struct clk *clk; | ||
46 | struct platform_device *pdev; | ||
47 | unsigned new_1:1; | ||
48 | |||
49 | u8 stopping; | ||
50 | struct list_head queue; | ||
51 | struct spi_transfer *current_transfer; | ||
52 | unsigned long remaining_bytes; | ||
53 | |||
54 | void *buffer; | ||
55 | dma_addr_t buffer_dma; | ||
56 | }; | ||
57 | |||
58 | #define BUFFER_SIZE PAGE_SIZE | ||
59 | #define INVALID_DMA_ADDRESS 0xffffffff | ||
60 | |||
61 | /* | ||
62 | * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby | ||
63 | * they assume that spi slave device state will not change on deselect, so | ||
64 | * that automagic deselection is OK. Not so! Workaround uses nCSx pins | ||
65 | * as GPIOs; or newer controllers have CSAAT and friends. | ||
66 | * | ||
67 | * Since the CSAAT functionality is a bit weird on newer controllers | ||
68 | * as well, we use GPIO to control nCSx pins on all controllers. | ||
69 | */ | ||
70 | |||
71 | static inline void cs_activate(struct spi_device *spi) | ||
72 | { | ||
73 | unsigned gpio = (unsigned) spi->controller_data; | ||
74 | unsigned active = spi->mode & SPI_CS_HIGH; | ||
75 | |||
76 | dev_dbg(&spi->dev, "activate %u%s\n", gpio, active ? " (high)" : ""); | ||
77 | gpio_set_value(gpio, active); | ||
78 | } | ||
79 | |||
80 | static inline void cs_deactivate(struct spi_device *spi) | ||
81 | { | ||
82 | unsigned gpio = (unsigned) spi->controller_data; | ||
83 | unsigned active = spi->mode & SPI_CS_HIGH; | ||
84 | |||
85 | dev_dbg(&spi->dev, "DEactivate %u%s\n", gpio, active ? " (low)" : ""); | ||
86 | gpio_set_value(gpio, !active); | ||
87 | } | ||
88 | |||
89 | /* | ||
90 | * Submit next transfer for DMA. | ||
91 | * lock is held, spi irq is blocked | ||
92 | */ | ||
93 | static void atmel_spi_next_xfer(struct spi_master *master, | ||
94 | struct spi_message *msg) | ||
95 | { | ||
96 | struct atmel_spi *as = spi_master_get_devdata(master); | ||
97 | struct spi_transfer *xfer; | ||
98 | u32 len; | ||
99 | dma_addr_t tx_dma, rx_dma; | ||
100 | |||
101 | xfer = as->current_transfer; | ||
102 | if (!xfer || as->remaining_bytes == 0) { | ||
103 | if (xfer) | ||
104 | xfer = list_entry(xfer->transfer_list.next, | ||
105 | struct spi_transfer, transfer_list); | ||
106 | else | ||
107 | xfer = list_entry(msg->transfers.next, | ||
108 | struct spi_transfer, transfer_list); | ||
109 | as->remaining_bytes = xfer->len; | ||
110 | as->current_transfer = xfer; | ||
111 | } | ||
112 | |||
113 | len = as->remaining_bytes; | ||
114 | |||
115 | tx_dma = xfer->tx_dma; | ||
116 | rx_dma = xfer->rx_dma; | ||
117 | |||
118 | /* use scratch buffer only when rx or tx data is unspecified */ | ||
119 | if (rx_dma == INVALID_DMA_ADDRESS) { | ||
120 | rx_dma = as->buffer_dma; | ||
121 | if (len > BUFFER_SIZE) | ||
122 | len = BUFFER_SIZE; | ||
123 | } | ||
124 | if (tx_dma == INVALID_DMA_ADDRESS) { | ||
125 | tx_dma = as->buffer_dma; | ||
126 | if (len > BUFFER_SIZE) | ||
127 | len = BUFFER_SIZE; | ||
128 | memset(as->buffer, 0, len); | ||
129 | dma_sync_single_for_device(&as->pdev->dev, | ||
130 | as->buffer_dma, len, DMA_TO_DEVICE); | ||
131 | } | ||
132 | |||
133 | spi_writel(as, RPR, rx_dma); | ||
134 | spi_writel(as, TPR, tx_dma); | ||
135 | |||
136 | as->remaining_bytes -= len; | ||
137 | if (msg->spi->bits_per_word > 8) | ||
138 | len >>= 1; | ||
139 | |||
140 | /* REVISIT: when xfer->delay_usecs == 0, the PDC "next transfer" | ||
141 | * mechanism might help avoid the IRQ latency between transfers | ||
142 | * | ||
143 | * We're also waiting for ENDRX before we start the next | ||
144 | * transfer because we need to handle some difficult timing | ||
145 | * issues otherwise. If we wait for ENDTX in one transfer and | ||
146 | * then starts waiting for ENDRX in the next, it's difficult | ||
147 | * to tell the difference between the ENDRX interrupt we're | ||
148 | * actually waiting for and the ENDRX interrupt of the | ||
149 | * previous transfer. | ||
150 | * | ||
151 | * It should be doable, though. Just not now... | ||
152 | */ | ||
153 | spi_writel(as, TNCR, 0); | ||
154 | spi_writel(as, RNCR, 0); | ||
155 | spi_writel(as, IER, SPI_BIT(ENDRX) | SPI_BIT(OVRES)); | ||
156 | |||
157 | dev_dbg(&msg->spi->dev, | ||
158 | " start xfer %p: len %u tx %p/%08x rx %p/%08x imr %03x\n", | ||
159 | xfer, xfer->len, xfer->tx_buf, xfer->tx_dma, | ||
160 | xfer->rx_buf, xfer->rx_dma, spi_readl(as, IMR)); | ||
161 | |||
162 | spi_writel(as, TCR, len); | ||
163 | spi_writel(as, RCR, len); | ||
164 | spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN)); | ||
165 | } | ||
166 | |||
167 | static void atmel_spi_next_message(struct spi_master *master) | ||
168 | { | ||
169 | struct atmel_spi *as = spi_master_get_devdata(master); | ||
170 | struct spi_message *msg; | ||
171 | u32 mr; | ||
172 | |||
173 | BUG_ON(as->current_transfer); | ||
174 | |||
175 | msg = list_entry(as->queue.next, struct spi_message, queue); | ||
176 | |||
177 | /* Select the chip */ | ||
178 | mr = spi_readl(as, MR); | ||
179 | mr = SPI_BFINS(PCS, ~(1 << msg->spi->chip_select), mr); | ||
180 | spi_writel(as, MR, mr); | ||
181 | cs_activate(msg->spi); | ||
182 | |||
183 | atmel_spi_next_xfer(master, msg); | ||
184 | } | ||
185 | |||
186 | static void | ||
187 | atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer) | ||
188 | { | ||
189 | xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS; | ||
190 | if (xfer->tx_buf) | ||
191 | xfer->tx_dma = dma_map_single(&as->pdev->dev, | ||
192 | (void *) xfer->tx_buf, xfer->len, | ||
193 | DMA_TO_DEVICE); | ||
194 | if (xfer->rx_buf) | ||
195 | xfer->rx_dma = dma_map_single(&as->pdev->dev, | ||
196 | xfer->rx_buf, xfer->len, | ||
197 | DMA_FROM_DEVICE); | ||
198 | } | ||
199 | |||
200 | static void atmel_spi_dma_unmap_xfer(struct spi_master *master, | ||
201 | struct spi_transfer *xfer) | ||
202 | { | ||
203 | if (xfer->tx_dma != INVALID_DMA_ADDRESS) | ||
204 | dma_unmap_single(master->cdev.dev, xfer->tx_dma, | ||
205 | xfer->len, DMA_TO_DEVICE); | ||
206 | if (xfer->rx_dma != INVALID_DMA_ADDRESS) | ||
207 | dma_unmap_single(master->cdev.dev, xfer->rx_dma, | ||
208 | xfer->len, DMA_FROM_DEVICE); | ||
209 | } | ||
210 | |||
211 | static void | ||
212 | atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as, | ||
213 | struct spi_message *msg, int status) | ||
214 | { | ||
215 | cs_deactivate(msg->spi); | ||
216 | list_del(&msg->queue); | ||
217 | msg->status = status; | ||
218 | |||
219 | dev_dbg(master->cdev.dev, | ||
220 | "xfer complete: %u bytes transferred\n", | ||
221 | msg->actual_length); | ||
222 | |||
223 | spin_unlock(&as->lock); | ||
224 | msg->complete(msg->context); | ||
225 | spin_lock(&as->lock); | ||
226 | |||
227 | as->current_transfer = NULL; | ||
228 | |||
229 | /* continue if needed */ | ||
230 | if (list_empty(&as->queue) || as->stopping) | ||
231 | spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); | ||
232 | else | ||
233 | atmel_spi_next_message(master); | ||
234 | } | ||
235 | |||
236 | static irqreturn_t | ||
237 | atmel_spi_interrupt(int irq, void *dev_id) | ||
238 | { | ||
239 | struct spi_master *master = dev_id; | ||
240 | struct atmel_spi *as = spi_master_get_devdata(master); | ||
241 | struct spi_message *msg; | ||
242 | struct spi_transfer *xfer; | ||
243 | u32 status, pending, imr; | ||
244 | int ret = IRQ_NONE; | ||
245 | |||
246 | spin_lock(&as->lock); | ||
247 | |||
248 | xfer = as->current_transfer; | ||
249 | msg = list_entry(as->queue.next, struct spi_message, queue); | ||
250 | |||
251 | imr = spi_readl(as, IMR); | ||
252 | status = spi_readl(as, SR); | ||
253 | pending = status & imr; | ||
254 | |||
255 | if (pending & SPI_BIT(OVRES)) { | ||
256 | int timeout; | ||
257 | |||
258 | ret = IRQ_HANDLED; | ||
259 | |||
260 | spi_writel(as, IDR, (SPI_BIT(ENDTX) | SPI_BIT(ENDRX) | ||
261 | | SPI_BIT(OVRES))); | ||
262 | |||
263 | /* | ||
264 | * When we get an overrun, we disregard the current | ||
265 | * transfer. Data will not be copied back from any | ||
266 | * bounce buffer and msg->actual_len will not be | ||
267 | * updated with the last xfer. | ||
268 | * | ||
269 | * We will also not process any remaning transfers in | ||
270 | * the message. | ||
271 | * | ||
272 | * First, stop the transfer and unmap the DMA buffers. | ||
273 | */ | ||
274 | spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); | ||
275 | if (!msg->is_dma_mapped) | ||
276 | atmel_spi_dma_unmap_xfer(master, xfer); | ||
277 | |||
278 | /* REVISIT: udelay in irq is unfriendly */ | ||
279 | if (xfer->delay_usecs) | ||
280 | udelay(xfer->delay_usecs); | ||
281 | |||
282 | dev_warn(master->cdev.dev, "fifo overrun (%u/%u remaining)\n", | ||
283 | spi_readl(as, TCR), spi_readl(as, RCR)); | ||
284 | |||
285 | /* | ||
286 | * Clean up DMA registers and make sure the data | ||
287 | * registers are empty. | ||
288 | */ | ||
289 | spi_writel(as, RNCR, 0); | ||
290 | spi_writel(as, TNCR, 0); | ||
291 | spi_writel(as, RCR, 0); | ||
292 | spi_writel(as, TCR, 0); | ||
293 | for (timeout = 1000; timeout; timeout--) | ||
294 | if (spi_readl(as, SR) & SPI_BIT(TXEMPTY)) | ||
295 | break; | ||
296 | if (!timeout) | ||
297 | dev_warn(master->cdev.dev, | ||
298 | "timeout waiting for TXEMPTY"); | ||
299 | while (spi_readl(as, SR) & SPI_BIT(RDRF)) | ||
300 | spi_readl(as, RDR); | ||
301 | |||
302 | /* Clear any overrun happening while cleaning up */ | ||
303 | spi_readl(as, SR); | ||
304 | |||
305 | atmel_spi_msg_done(master, as, msg, -EIO); | ||
306 | } else if (pending & SPI_BIT(ENDRX)) { | ||
307 | ret = IRQ_HANDLED; | ||
308 | |||
309 | spi_writel(as, IDR, pending); | ||
310 | |||
311 | if (as->remaining_bytes == 0) { | ||
312 | msg->actual_length += xfer->len; | ||
313 | |||
314 | if (!msg->is_dma_mapped) | ||
315 | atmel_spi_dma_unmap_xfer(master, xfer); | ||
316 | |||
317 | /* REVISIT: udelay in irq is unfriendly */ | ||
318 | if (xfer->delay_usecs) | ||
319 | udelay(xfer->delay_usecs); | ||
320 | |||
321 | if (msg->transfers.prev == &xfer->transfer_list) { | ||
322 | /* report completed message */ | ||
323 | atmel_spi_msg_done(master, as, msg, 0); | ||
324 | } else { | ||
325 | if (xfer->cs_change) { | ||
326 | cs_deactivate(msg->spi); | ||
327 | udelay(1); | ||
328 | cs_activate(msg->spi); | ||
329 | } | ||
330 | |||
331 | /* | ||
332 | * Not done yet. Submit the next transfer. | ||
333 | * | ||
334 | * FIXME handle protocol options for xfer | ||
335 | */ | ||
336 | atmel_spi_next_xfer(master, msg); | ||
337 | } | ||
338 | } else { | ||
339 | /* | ||
340 | * Keep going, we still have data to send in | ||
341 | * the current transfer. | ||
342 | */ | ||
343 | atmel_spi_next_xfer(master, msg); | ||
344 | } | ||
345 | } | ||
346 | |||
347 | spin_unlock(&as->lock); | ||
348 | |||
349 | return ret; | ||
350 | } | ||
351 | |||
352 | #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH) | ||
353 | |||
354 | static int atmel_spi_setup(struct spi_device *spi) | ||
355 | { | ||
356 | struct atmel_spi *as; | ||
357 | u32 scbr, csr; | ||
358 | unsigned int bits = spi->bits_per_word; | ||
359 | unsigned long bus_hz, sck_hz; | ||
360 | unsigned int npcs_pin; | ||
361 | int ret; | ||
362 | |||
363 | as = spi_master_get_devdata(spi->master); | ||
364 | |||
365 | if (as->stopping) | ||
366 | return -ESHUTDOWN; | ||
367 | |||
368 | if (spi->chip_select > spi->master->num_chipselect) { | ||
369 | dev_dbg(&spi->dev, | ||
370 | "setup: invalid chipselect %u (%u defined)\n", | ||
371 | spi->chip_select, spi->master->num_chipselect); | ||
372 | return -EINVAL; | ||
373 | } | ||
374 | |||
375 | if (bits == 0) | ||
376 | bits = 8; | ||
377 | if (bits < 8 || bits > 16) { | ||
378 | dev_dbg(&spi->dev, | ||
379 | "setup: invalid bits_per_word %u (8 to 16)\n", | ||
380 | bits); | ||
381 | return -EINVAL; | ||
382 | } | ||
383 | |||
384 | if (spi->mode & ~MODEBITS) { | ||
385 | dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n", | ||
386 | spi->mode & ~MODEBITS); | ||
387 | return -EINVAL; | ||
388 | } | ||
389 | |||
390 | /* speed zero convention is used by some upper layers */ | ||
391 | bus_hz = clk_get_rate(as->clk); | ||
392 | if (spi->max_speed_hz) { | ||
393 | /* assume div32/fdiv/mbz == 0 */ | ||
394 | if (!as->new_1) | ||
395 | bus_hz /= 2; | ||
396 | scbr = ((bus_hz + spi->max_speed_hz - 1) | ||
397 | / spi->max_speed_hz); | ||
398 | if (scbr >= (1 << SPI_SCBR_SIZE)) { | ||
399 | dev_dbg(&spi->dev, "setup: %d Hz too slow, scbr %u\n", | ||
400 | spi->max_speed_hz, scbr); | ||
401 | return -EINVAL; | ||
402 | } | ||
403 | } else | ||
404 | scbr = 0xff; | ||
405 | sck_hz = bus_hz / scbr; | ||
406 | |||
407 | csr = SPI_BF(SCBR, scbr) | SPI_BF(BITS, bits - 8); | ||
408 | if (spi->mode & SPI_CPOL) | ||
409 | csr |= SPI_BIT(CPOL); | ||
410 | if (!(spi->mode & SPI_CPHA)) | ||
411 | csr |= SPI_BIT(NCPHA); | ||
412 | |||
413 | /* TODO: DLYBS and DLYBCT */ | ||
414 | csr |= SPI_BF(DLYBS, 10); | ||
415 | csr |= SPI_BF(DLYBCT, 10); | ||
416 | |||
417 | /* chipselect must have been muxed as GPIO (e.g. in board setup) */ | ||
418 | npcs_pin = (unsigned int)spi->controller_data; | ||
419 | if (!spi->controller_state) { | ||
420 | ret = gpio_request(npcs_pin, "spi_npcs"); | ||
421 | if (ret) | ||
422 | return ret; | ||
423 | spi->controller_state = (void *)npcs_pin; | ||
424 | gpio_direction_output(npcs_pin); | ||
425 | } | ||
426 | |||
427 | dev_dbg(&spi->dev, | ||
428 | "setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n", | ||
429 | sck_hz, bits, spi->mode, spi->chip_select, csr); | ||
430 | |||
431 | spi_writel(as, CSR0 + 4 * spi->chip_select, csr); | ||
432 | |||
433 | return 0; | ||
434 | } | ||
435 | |||
436 | static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) | ||
437 | { | ||
438 | struct atmel_spi *as; | ||
439 | struct spi_transfer *xfer; | ||
440 | unsigned long flags; | ||
441 | struct device *controller = spi->master->cdev.dev; | ||
442 | |||
443 | as = spi_master_get_devdata(spi->master); | ||
444 | |||
445 | dev_dbg(controller, "new message %p submitted for %s\n", | ||
446 | msg, spi->dev.bus_id); | ||
447 | |||
448 | if (unlikely(list_empty(&msg->transfers) | ||
449 | || !spi->max_speed_hz)) | ||
450 | return -EINVAL; | ||
451 | |||
452 | if (as->stopping) | ||
453 | return -ESHUTDOWN; | ||
454 | |||
455 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | ||
456 | if (!(xfer->tx_buf || xfer->rx_buf)) { | ||
457 | dev_dbg(&spi->dev, "missing rx or tx buf\n"); | ||
458 | return -EINVAL; | ||
459 | } | ||
460 | |||
461 | /* FIXME implement these protocol options!! */ | ||
462 | if (xfer->bits_per_word || xfer->speed_hz) { | ||
463 | dev_dbg(&spi->dev, "no protocol options yet\n"); | ||
464 | return -ENOPROTOOPT; | ||
465 | } | ||
466 | } | ||
467 | |||
468 | /* scrub dcache "early" */ | ||
469 | if (!msg->is_dma_mapped) { | ||
470 | list_for_each_entry(xfer, &msg->transfers, transfer_list) | ||
471 | atmel_spi_dma_map_xfer(as, xfer); | ||
472 | } | ||
473 | |||
474 | list_for_each_entry(xfer, &msg->transfers, transfer_list) { | ||
475 | dev_dbg(controller, | ||
476 | " xfer %p: len %u tx %p/%08x rx %p/%08x\n", | ||
477 | xfer, xfer->len, | ||
478 | xfer->tx_buf, xfer->tx_dma, | ||
479 | xfer->rx_buf, xfer->rx_dma); | ||
480 | } | ||
481 | |||
482 | msg->status = -EINPROGRESS; | ||
483 | msg->actual_length = 0; | ||
484 | |||
485 | spin_lock_irqsave(&as->lock, flags); | ||
486 | list_add_tail(&msg->queue, &as->queue); | ||
487 | if (!as->current_transfer) | ||
488 | atmel_spi_next_message(spi->master); | ||
489 | spin_unlock_irqrestore(&as->lock, flags); | ||
490 | |||
491 | return 0; | ||
492 | } | ||
493 | |||
494 | static void atmel_spi_cleanup(const struct spi_device *spi) | ||
495 | { | ||
496 | if (spi->controller_state) | ||
497 | gpio_free((unsigned int)spi->controller_data); | ||
498 | } | ||
499 | |||
500 | /*-------------------------------------------------------------------------*/ | ||
501 | |||
502 | static int __init atmel_spi_probe(struct platform_device *pdev) | ||
503 | { | ||
504 | struct resource *regs; | ||
505 | int irq; | ||
506 | struct clk *clk; | ||
507 | int ret; | ||
508 | struct spi_master *master; | ||
509 | struct atmel_spi *as; | ||
510 | |||
511 | regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); | ||
512 | if (!regs) | ||
513 | return -ENXIO; | ||
514 | |||
515 | irq = platform_get_irq(pdev, 0); | ||
516 | if (irq < 0) | ||
517 | return irq; | ||
518 | |||
519 | clk = clk_get(&pdev->dev, "spi_clk"); | ||
520 | if (IS_ERR(clk)) | ||
521 | return PTR_ERR(clk); | ||
522 | |||
523 | /* setup spi core then atmel-specific driver state */ | ||
524 | ret = -ENOMEM; | ||
525 | master = spi_alloc_master(&pdev->dev, sizeof *as); | ||
526 | if (!master) | ||
527 | goto out_free; | ||
528 | |||
529 | master->bus_num = pdev->id; | ||
530 | master->num_chipselect = 4; | ||
531 | master->setup = atmel_spi_setup; | ||
532 | master->transfer = atmel_spi_transfer; | ||
533 | master->cleanup = atmel_spi_cleanup; | ||
534 | platform_set_drvdata(pdev, master); | ||
535 | |||
536 | as = spi_master_get_devdata(master); | ||
537 | |||
538 | as->buffer = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE, | ||
539 | &as->buffer_dma, GFP_KERNEL); | ||
540 | if (!as->buffer) | ||
541 | goto out_free; | ||
542 | |||
543 | spin_lock_init(&as->lock); | ||
544 | INIT_LIST_HEAD(&as->queue); | ||
545 | as->pdev = pdev; | ||
546 | as->regs = ioremap(regs->start, (regs->end - regs->start) + 1); | ||
547 | if (!as->regs) | ||
548 | goto out_free_buffer; | ||
549 | as->irq = irq; | ||
550 | as->clk = clk; | ||
551 | #ifdef CONFIG_ARCH_AT91 | ||
552 | if (!cpu_is_at91rm9200()) | ||
553 | as->new_1 = 1; | ||
554 | #endif | ||
555 | |||
556 | ret = request_irq(irq, atmel_spi_interrupt, 0, | ||
557 | pdev->dev.bus_id, master); | ||
558 | if (ret) | ||
559 | goto out_unmap_regs; | ||
560 | |||
561 | /* Initialize the hardware */ | ||
562 | clk_enable(clk); | ||
563 | spi_writel(as, CR, SPI_BIT(SWRST)); | ||
564 | spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS)); | ||
565 | spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); | ||
566 | spi_writel(as, CR, SPI_BIT(SPIEN)); | ||
567 | |||
568 | /* go! */ | ||
569 | dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n", | ||
570 | (unsigned long)regs->start, irq); | ||
571 | |||
572 | ret = spi_register_master(master); | ||
573 | if (ret) | ||
574 | goto out_reset_hw; | ||
575 | |||
576 | return 0; | ||
577 | |||
578 | out_reset_hw: | ||
579 | spi_writel(as, CR, SPI_BIT(SWRST)); | ||
580 | clk_disable(clk); | ||
581 | free_irq(irq, master); | ||
582 | out_unmap_regs: | ||
583 | iounmap(as->regs); | ||
584 | out_free_buffer: | ||
585 | dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer, | ||
586 | as->buffer_dma); | ||
587 | out_free: | ||
588 | clk_put(clk); | ||
589 | spi_master_put(master); | ||
590 | return ret; | ||
591 | } | ||
592 | |||
593 | static int __exit atmel_spi_remove(struct platform_device *pdev) | ||
594 | { | ||
595 | struct spi_master *master = platform_get_drvdata(pdev); | ||
596 | struct atmel_spi *as = spi_master_get_devdata(master); | ||
597 | struct spi_message *msg; | ||
598 | |||
599 | /* reset the hardware and block queue progress */ | ||
600 | spin_lock_irq(&as->lock); | ||
601 | as->stopping = 1; | ||
602 | spi_writel(as, CR, SPI_BIT(SWRST)); | ||
603 | spi_readl(as, SR); | ||
604 | spin_unlock_irq(&as->lock); | ||
605 | |||
606 | /* Terminate remaining queued transfers */ | ||
607 | list_for_each_entry(msg, &as->queue, queue) { | ||
608 | /* REVISIT unmapping the dma is a NOP on ARM and AVR32 | ||
609 | * but we shouldn't depend on that... | ||
610 | */ | ||
611 | msg->status = -ESHUTDOWN; | ||
612 | msg->complete(msg->context); | ||
613 | } | ||
614 | |||
615 | dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer, | ||
616 | as->buffer_dma); | ||
617 | |||
618 | clk_disable(as->clk); | ||
619 | clk_put(as->clk); | ||
620 | free_irq(as->irq, master); | ||
621 | iounmap(as->regs); | ||
622 | |||
623 | spi_unregister_master(master); | ||
624 | |||
625 | return 0; | ||
626 | } | ||
627 | |||
628 | #ifdef CONFIG_PM | ||
629 | |||
630 | static int atmel_spi_suspend(struct platform_device *pdev, pm_message_t mesg) | ||
631 | { | ||
632 | struct spi_master *master = platform_get_drvdata(pdev); | ||
633 | struct atmel_spi *as = spi_master_get_devdata(master); | ||
634 | |||
635 | clk_disable(as->clk); | ||
636 | return 0; | ||
637 | } | ||
638 | |||
639 | static int atmel_spi_resume(struct platform_device *pdev) | ||
640 | { | ||
641 | struct spi_master *master = platform_get_drvdata(pdev); | ||
642 | struct atmel_spi *as = spi_master_get_devdata(master); | ||
643 | |||
644 | clk_enable(as->clk); | ||
645 | return 0; | ||
646 | } | ||
647 | |||
648 | #else | ||
649 | #define atmel_spi_suspend NULL | ||
650 | #define atmel_spi_resume NULL | ||
651 | #endif | ||
652 | |||
653 | |||
654 | static struct platform_driver atmel_spi_driver = { | ||
655 | .driver = { | ||
656 | .name = "atmel_spi", | ||
657 | .owner = THIS_MODULE, | ||
658 | }, | ||
659 | .suspend = atmel_spi_suspend, | ||
660 | .resume = atmel_spi_resume, | ||
661 | .remove = __exit_p(atmel_spi_remove), | ||
662 | }; | ||
663 | |||
664 | static int __init atmel_spi_init(void) | ||
665 | { | ||
666 | return platform_driver_probe(&atmel_spi_driver, atmel_spi_probe); | ||
667 | } | ||
668 | module_init(atmel_spi_init); | ||
669 | |||
670 | static void __exit atmel_spi_exit(void) | ||
671 | { | ||
672 | platform_driver_unregister(&atmel_spi_driver); | ||
673 | } | ||
674 | module_exit(atmel_spi_exit); | ||
675 | |||
676 | MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver"); | ||
677 | MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>"); | ||
678 | MODULE_LICENSE("GPL"); | ||