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ccf06998 KG |
1 | /* |
2 | * MPC83xx SPI controller driver. | |
3 | * | |
4 | * Maintainer: Kumar Gala | |
5 | * | |
6 | * Copyright (C) 2006 Polycom, Inc. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the | |
10 | * Free Software Foundation; either version 2 of the License, or (at your | |
11 | * option) any later version. | |
12 | */ | |
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/completion.h> | |
18 | #include <linux/interrupt.h> | |
19 | #include <linux/delay.h> | |
20 | #include <linux/irq.h> | |
21 | #include <linux/device.h> | |
22 | #include <linux/spi/spi.h> | |
23 | #include <linux/spi/spi_bitbang.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/fsl_devices.h> | |
26 | ||
27 | #include <asm/irq.h> | |
28 | #include <asm/io.h> | |
29 | ||
30 | /* SPI Controller registers */ | |
31 | struct mpc83xx_spi_reg { | |
32 | u8 res1[0x20]; | |
33 | __be32 mode; | |
34 | __be32 event; | |
35 | __be32 mask; | |
36 | __be32 command; | |
37 | __be32 transmit; | |
38 | __be32 receive; | |
39 | }; | |
40 | ||
41 | /* SPI Controller mode register definitions */ | |
42 | #define SPMODE_CI_INACTIVEHIGH (1 << 29) | |
43 | #define SPMODE_CP_BEGIN_EDGECLK (1 << 28) | |
44 | #define SPMODE_DIV16 (1 << 27) | |
45 | #define SPMODE_REV (1 << 26) | |
46 | #define SPMODE_MS (1 << 25) | |
47 | #define SPMODE_ENABLE (1 << 24) | |
48 | #define SPMODE_LEN(x) ((x) << 20) | |
49 | #define SPMODE_PM(x) ((x) << 16) | |
50 | ||
51 | /* | |
52 | * Default for SPI Mode: | |
53 | * SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk | |
54 | */ | |
55 | #define SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH | SPMODE_DIV16 | SPMODE_REV | \ | |
56 | SPMODE_MS | SPMODE_LEN(7) | SPMODE_PM(0xf)) | |
57 | ||
58 | /* SPIE register values */ | |
59 | #define SPIE_NE 0x00000200 /* Not empty */ | |
60 | #define SPIE_NF 0x00000100 /* Not full */ | |
61 | ||
62 | /* SPIM register values */ | |
63 | #define SPIM_NE 0x00000200 /* Not empty */ | |
64 | #define SPIM_NF 0x00000100 /* Not full */ | |
65 | ||
66 | /* SPI Controller driver's private data. */ | |
67 | struct mpc83xx_spi { | |
68 | /* bitbang has to be first */ | |
69 | struct spi_bitbang bitbang; | |
70 | struct completion done; | |
71 | ||
72 | struct mpc83xx_spi_reg __iomem *base; | |
73 | ||
74 | /* rx & tx bufs from the spi_transfer */ | |
75 | const void *tx; | |
76 | void *rx; | |
77 | ||
78 | /* functions to deal with different sized buffers */ | |
79 | void (*get_rx) (u32 rx_data, struct mpc83xx_spi *); | |
80 | u32(*get_tx) (struct mpc83xx_spi *); | |
81 | ||
82 | unsigned int count; | |
83 | u32 irq; | |
84 | ||
85 | unsigned nsecs; /* (clock cycle time)/2 */ | |
86 | ||
87 | u32 sysclk; | |
88 | void (*activate_cs) (u8 cs, u8 polarity); | |
89 | void (*deactivate_cs) (u8 cs, u8 polarity); | |
90 | }; | |
91 | ||
92 | static inline void mpc83xx_spi_write_reg(__be32 __iomem * reg, u32 val) | |
93 | { | |
94 | out_be32(reg, val); | |
95 | } | |
96 | ||
97 | static inline u32 mpc83xx_spi_read_reg(__be32 __iomem * reg) | |
98 | { | |
99 | return in_be32(reg); | |
100 | } | |
101 | ||
102 | #define MPC83XX_SPI_RX_BUF(type) \ | |
103 | void mpc83xx_spi_rx_buf_##type(u32 data, struct mpc83xx_spi *mpc83xx_spi) \ | |
104 | { \ | |
105 | type * rx = mpc83xx_spi->rx; \ | |
106 | *rx++ = (type)data; \ | |
107 | mpc83xx_spi->rx = rx; \ | |
108 | } | |
109 | ||
110 | #define MPC83XX_SPI_TX_BUF(type) \ | |
111 | u32 mpc83xx_spi_tx_buf_##type(struct mpc83xx_spi *mpc83xx_spi) \ | |
112 | { \ | |
113 | u32 data; \ | |
114 | const type * tx = mpc83xx_spi->tx; \ | |
4b1badf5 DB |
115 | if (!tx) \ |
116 | return 0; \ | |
ccf06998 KG |
117 | data = *tx++; \ |
118 | mpc83xx_spi->tx = tx; \ | |
119 | return data; \ | |
120 | } | |
121 | ||
122 | MPC83XX_SPI_RX_BUF(u8) | |
123 | MPC83XX_SPI_RX_BUF(u16) | |
124 | MPC83XX_SPI_RX_BUF(u32) | |
125 | MPC83XX_SPI_TX_BUF(u8) | |
126 | MPC83XX_SPI_TX_BUF(u16) | |
127 | MPC83XX_SPI_TX_BUF(u32) | |
128 | ||
129 | static void mpc83xx_spi_chipselect(struct spi_device *spi, int value) | |
130 | { | |
131 | struct mpc83xx_spi *mpc83xx_spi; | |
132 | u8 pol = spi->mode & SPI_CS_HIGH ? 1 : 0; | |
133 | ||
134 | mpc83xx_spi = spi_master_get_devdata(spi->master); | |
135 | ||
136 | if (value == BITBANG_CS_INACTIVE) { | |
137 | if (mpc83xx_spi->deactivate_cs) | |
138 | mpc83xx_spi->deactivate_cs(spi->chip_select, pol); | |
139 | } | |
140 | ||
141 | if (value == BITBANG_CS_ACTIVE) { | |
142 | u32 regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode); | |
143 | u32 len = spi->bits_per_word; | |
144 | if (len == 32) | |
145 | len = 0; | |
146 | else | |
147 | len = len - 1; | |
148 | ||
149 | /* mask out bits we are going to set */ | |
150 | regval &= ~0x38ff0000; | |
151 | ||
152 | if (spi->mode & SPI_CPHA) | |
153 | regval |= SPMODE_CP_BEGIN_EDGECLK; | |
154 | if (spi->mode & SPI_CPOL) | |
155 | regval |= SPMODE_CI_INACTIVEHIGH; | |
156 | ||
157 | regval |= SPMODE_LEN(len); | |
158 | ||
159 | if ((mpc83xx_spi->sysclk / spi->max_speed_hz) >= 64) { | |
160 | u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 64); | |
698ca47e CW |
161 | if (pm > 0x0f) { |
162 | printk(KERN_WARNING "MPC83xx SPI: SPICLK can't be less then a SYSCLK/1024!\n" | |
163 | "Requested SPICLK is %d Hz. Will use %d Hz instead.\n", | |
164 | spi->max_speed_hz, mpc83xx_spi->sysclk / 1024); | |
165 | pm = 0x0f; | |
166 | } | |
ccf06998 KG |
167 | regval |= SPMODE_PM(pm) | SPMODE_DIV16; |
168 | } else { | |
169 | u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 4); | |
170 | regval |= SPMODE_PM(pm); | |
171 | } | |
172 | ||
173 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval); | |
174 | if (mpc83xx_spi->activate_cs) | |
175 | mpc83xx_spi->activate_cs(spi->chip_select, pol); | |
176 | } | |
177 | } | |
178 | ||
179 | static | |
180 | int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) | |
181 | { | |
182 | struct mpc83xx_spi *mpc83xx_spi; | |
183 | u32 regval; | |
184 | u8 bits_per_word; | |
185 | u32 hz; | |
186 | ||
187 | mpc83xx_spi = spi_master_get_devdata(spi->master); | |
188 | ||
189 | if (t) { | |
190 | bits_per_word = t->bits_per_word; | |
191 | hz = t->speed_hz; | |
192 | } else { | |
193 | bits_per_word = 0; | |
194 | hz = 0; | |
195 | } | |
196 | ||
197 | /* spi_transfer level calls that work per-word */ | |
198 | if (!bits_per_word) | |
199 | bits_per_word = spi->bits_per_word; | |
200 | ||
201 | /* Make sure its a bit width we support [4..16, 32] */ | |
202 | if ((bits_per_word < 4) | |
203 | || ((bits_per_word > 16) && (bits_per_word != 32))) | |
204 | return -EINVAL; | |
205 | ||
206 | if (bits_per_word <= 8) { | |
207 | mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8; | |
208 | mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8; | |
209 | } else if (bits_per_word <= 16) { | |
210 | mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u16; | |
211 | mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u16; | |
212 | } else if (bits_per_word <= 32) { | |
213 | mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u32; | |
214 | mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u32; | |
215 | } else | |
216 | return -EINVAL; | |
217 | ||
218 | /* nsecs = (clock period)/2 */ | |
219 | if (!hz) | |
220 | hz = spi->max_speed_hz; | |
221 | mpc83xx_spi->nsecs = (1000000000 / 2) / hz; | |
222 | if (mpc83xx_spi->nsecs > MAX_UDELAY_MS * 1000) | |
223 | return -EINVAL; | |
224 | ||
225 | if (bits_per_word == 32) | |
226 | bits_per_word = 0; | |
227 | else | |
228 | bits_per_word = bits_per_word - 1; | |
229 | ||
230 | regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode); | |
231 | ||
232 | /* Mask out bits_per_wordgth */ | |
233 | regval &= 0xff0fffff; | |
234 | regval |= SPMODE_LEN(bits_per_word); | |
235 | ||
236 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval); | |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
dccd573b DB |
241 | /* the spi->mode bits understood by this driver: */ |
242 | #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH) | |
243 | ||
ccf06998 KG |
244 | static int mpc83xx_spi_setup(struct spi_device *spi) |
245 | { | |
246 | struct spi_bitbang *bitbang; | |
247 | struct mpc83xx_spi *mpc83xx_spi; | |
248 | int retval; | |
249 | ||
dccd573b DB |
250 | if (spi->mode & ~MODEBITS) { |
251 | dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n", | |
252 | spi->mode & ~MODEBITS); | |
253 | return -EINVAL; | |
254 | } | |
255 | ||
ccf06998 KG |
256 | if (!spi->max_speed_hz) |
257 | return -EINVAL; | |
258 | ||
259 | bitbang = spi_master_get_devdata(spi->master); | |
260 | mpc83xx_spi = spi_master_get_devdata(spi->master); | |
261 | ||
262 | if (!spi->bits_per_word) | |
263 | spi->bits_per_word = 8; | |
264 | ||
265 | retval = mpc83xx_spi_setup_transfer(spi, NULL); | |
266 | if (retval < 0) | |
267 | return retval; | |
268 | ||
269 | dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n", | |
270 | __FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA), | |
271 | spi->bits_per_word, 2 * mpc83xx_spi->nsecs); | |
272 | ||
273 | /* NOTE we _need_ to call chipselect() early, ideally with adapter | |
274 | * setup, unless the hardware defaults cooperate to avoid confusion | |
275 | * between normal (active low) and inverted chipselects. | |
276 | */ | |
277 | ||
278 | /* deselect chip (low or high) */ | |
279 | spin_lock(&bitbang->lock); | |
280 | if (!bitbang->busy) { | |
281 | bitbang->chipselect(spi, BITBANG_CS_INACTIVE); | |
282 | ndelay(mpc83xx_spi->nsecs); | |
283 | } | |
284 | spin_unlock(&bitbang->lock); | |
285 | ||
286 | return 0; | |
287 | } | |
288 | ||
289 | static int mpc83xx_spi_bufs(struct spi_device *spi, struct spi_transfer *t) | |
290 | { | |
291 | struct mpc83xx_spi *mpc83xx_spi; | |
292 | u32 word; | |
293 | ||
294 | mpc83xx_spi = spi_master_get_devdata(spi->master); | |
295 | ||
296 | mpc83xx_spi->tx = t->tx_buf; | |
297 | mpc83xx_spi->rx = t->rx_buf; | |
298 | mpc83xx_spi->count = t->len; | |
299 | INIT_COMPLETION(mpc83xx_spi->done); | |
300 | ||
301 | /* enable rx ints */ | |
302 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, SPIM_NE); | |
303 | ||
304 | /* transmit word */ | |
305 | word = mpc83xx_spi->get_tx(mpc83xx_spi); | |
306 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word); | |
307 | ||
308 | wait_for_completion(&mpc83xx_spi->done); | |
309 | ||
310 | /* disable rx ints */ | |
311 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0); | |
312 | ||
313 | return t->len - mpc83xx_spi->count; | |
314 | } | |
315 | ||
7d12e780 | 316 | irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data) |
ccf06998 KG |
317 | { |
318 | struct mpc83xx_spi *mpc83xx_spi = context_data; | |
319 | u32 event; | |
320 | irqreturn_t ret = IRQ_NONE; | |
321 | ||
322 | /* Get interrupt events(tx/rx) */ | |
323 | event = mpc83xx_spi_read_reg(&mpc83xx_spi->base->event); | |
324 | ||
325 | /* We need handle RX first */ | |
326 | if (event & SPIE_NE) { | |
327 | u32 rx_data = mpc83xx_spi_read_reg(&mpc83xx_spi->base->receive); | |
328 | ||
329 | if (mpc83xx_spi->rx) | |
330 | mpc83xx_spi->get_rx(rx_data, mpc83xx_spi); | |
331 | ||
332 | ret = IRQ_HANDLED; | |
333 | } | |
334 | ||
335 | if ((event & SPIE_NF) == 0) | |
336 | /* spin until TX is done */ | |
337 | while (((event = | |
338 | mpc83xx_spi_read_reg(&mpc83xx_spi->base->event)) & | |
339 | SPIE_NF) == 0) | |
340 | cpu_relax(); | |
341 | ||
342 | mpc83xx_spi->count -= 1; | |
343 | if (mpc83xx_spi->count) { | |
344 | if (mpc83xx_spi->tx) { | |
345 | u32 word = mpc83xx_spi->get_tx(mpc83xx_spi); | |
346 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, | |
347 | word); | |
348 | } | |
349 | } else { | |
350 | complete(&mpc83xx_spi->done); | |
351 | } | |
352 | ||
353 | /* Clear the events */ | |
354 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, event); | |
355 | ||
356 | return ret; | |
357 | } | |
358 | ||
359 | static int __init mpc83xx_spi_probe(struct platform_device *dev) | |
360 | { | |
361 | struct spi_master *master; | |
362 | struct mpc83xx_spi *mpc83xx_spi; | |
363 | struct fsl_spi_platform_data *pdata; | |
364 | struct resource *r; | |
365 | u32 regval; | |
366 | int ret = 0; | |
367 | ||
368 | /* Get resources(memory, IRQ) associated with the device */ | |
369 | master = spi_alloc_master(&dev->dev, sizeof(struct mpc83xx_spi)); | |
370 | ||
371 | if (master == NULL) { | |
372 | ret = -ENOMEM; | |
373 | goto err; | |
374 | } | |
375 | ||
376 | platform_set_drvdata(dev, master); | |
377 | pdata = dev->dev.platform_data; | |
378 | ||
379 | if (pdata == NULL) { | |
380 | ret = -ENODEV; | |
381 | goto free_master; | |
382 | } | |
383 | ||
384 | r = platform_get_resource(dev, IORESOURCE_MEM, 0); | |
385 | if (r == NULL) { | |
386 | ret = -ENODEV; | |
387 | goto free_master; | |
388 | } | |
389 | ||
390 | mpc83xx_spi = spi_master_get_devdata(master); | |
391 | mpc83xx_spi->bitbang.master = spi_master_get(master); | |
392 | mpc83xx_spi->bitbang.chipselect = mpc83xx_spi_chipselect; | |
393 | mpc83xx_spi->bitbang.setup_transfer = mpc83xx_spi_setup_transfer; | |
394 | mpc83xx_spi->bitbang.txrx_bufs = mpc83xx_spi_bufs; | |
395 | mpc83xx_spi->sysclk = pdata->sysclk; | |
396 | mpc83xx_spi->activate_cs = pdata->activate_cs; | |
397 | mpc83xx_spi->deactivate_cs = pdata->deactivate_cs; | |
398 | mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8; | |
399 | mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8; | |
400 | ||
401 | mpc83xx_spi->bitbang.master->setup = mpc83xx_spi_setup; | |
402 | init_completion(&mpc83xx_spi->done); | |
403 | ||
404 | mpc83xx_spi->base = ioremap(r->start, r->end - r->start + 1); | |
405 | if (mpc83xx_spi->base == NULL) { | |
406 | ret = -ENOMEM; | |
407 | goto put_master; | |
408 | } | |
409 | ||
410 | mpc83xx_spi->irq = platform_get_irq(dev, 0); | |
411 | ||
412 | if (mpc83xx_spi->irq < 0) { | |
413 | ret = -ENXIO; | |
414 | goto unmap_io; | |
415 | } | |
416 | ||
417 | /* Register for SPI Interrupt */ | |
418 | ret = request_irq(mpc83xx_spi->irq, mpc83xx_spi_irq, | |
419 | 0, "mpc83xx_spi", mpc83xx_spi); | |
420 | ||
421 | if (ret != 0) | |
422 | goto unmap_io; | |
423 | ||
424 | master->bus_num = pdata->bus_num; | |
425 | master->num_chipselect = pdata->max_chipselect; | |
426 | ||
427 | /* SPI controller initializations */ | |
428 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0); | |
429 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0); | |
430 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->command, 0); | |
431 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, 0xffffffff); | |
432 | ||
433 | /* Enable SPI interface */ | |
434 | regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE; | |
435 | mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval); | |
436 | ||
437 | ret = spi_bitbang_start(&mpc83xx_spi->bitbang); | |
438 | ||
439 | if (ret != 0) | |
440 | goto free_irq; | |
441 | ||
442 | printk(KERN_INFO | |
443 | "%s: MPC83xx SPI Controller driver at 0x%p (irq = %d)\n", | |
444 | dev->dev.bus_id, mpc83xx_spi->base, mpc83xx_spi->irq); | |
445 | ||
446 | return ret; | |
447 | ||
448 | free_irq: | |
449 | free_irq(mpc83xx_spi->irq, mpc83xx_spi); | |
450 | unmap_io: | |
451 | iounmap(mpc83xx_spi->base); | |
452 | put_master: | |
453 | spi_master_put(master); | |
454 | free_master: | |
455 | kfree(master); | |
456 | err: | |
457 | return ret; | |
458 | } | |
459 | ||
460 | static int __devexit mpc83xx_spi_remove(struct platform_device *dev) | |
461 | { | |
462 | struct mpc83xx_spi *mpc83xx_spi; | |
463 | struct spi_master *master; | |
464 | ||
465 | master = platform_get_drvdata(dev); | |
466 | mpc83xx_spi = spi_master_get_devdata(master); | |
467 | ||
468 | spi_bitbang_stop(&mpc83xx_spi->bitbang); | |
469 | free_irq(mpc83xx_spi->irq, mpc83xx_spi); | |
470 | iounmap(mpc83xx_spi->base); | |
471 | spi_master_put(mpc83xx_spi->bitbang.master); | |
472 | ||
473 | return 0; | |
474 | } | |
475 | ||
476 | static struct platform_driver mpc83xx_spi_driver = { | |
477 | .probe = mpc83xx_spi_probe, | |
478 | .remove = __devexit_p(mpc83xx_spi_remove), | |
479 | .driver = { | |
480 | .name = "mpc83xx_spi", | |
481 | }, | |
482 | }; | |
483 | ||
484 | static int __init mpc83xx_spi_init(void) | |
485 | { | |
486 | return platform_driver_register(&mpc83xx_spi_driver); | |
487 | } | |
488 | ||
489 | static void __exit mpc83xx_spi_exit(void) | |
490 | { | |
491 | platform_driver_unregister(&mpc83xx_spi_driver); | |
492 | } | |
493 | ||
494 | module_init(mpc83xx_spi_init); | |
495 | module_exit(mpc83xx_spi_exit); | |
496 | ||
497 | MODULE_AUTHOR("Kumar Gala"); | |
498 | MODULE_DESCRIPTION("Simple MPC83xx SPI Driver"); | |
499 | MODULE_LICENSE("GPL"); |