]>
Commit | Line | Data |
---|---|---|
d29389de | 1 | /* |
ca632f55 | 2 | * SPI master driver using generic bitbanged GPIO |
d29389de DB |
3 | * |
4 | * Copyright (C) 2006,2008 David Brownell | |
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 as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | #include <linux/kernel.h> | |
d7614de4 | 21 | #include <linux/module.h> |
d29389de DB |
22 | #include <linux/init.h> |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/gpio.h> | |
ecc77773 | 25 | #include <linux/of.h> |
38ab18ca DM |
26 | #include <linux/of_device.h> |
27 | #include <linux/of_gpio.h> | |
d29389de DB |
28 | |
29 | #include <linux/spi/spi.h> | |
30 | #include <linux/spi/spi_bitbang.h> | |
31 | #include <linux/spi/spi_gpio.h> | |
32 | ||
33 | ||
34 | /* | |
35 | * This bitbanging SPI master driver should help make systems usable | |
36 | * when a native hardware SPI engine is not available, perhaps because | |
37 | * its driver isn't yet working or because the I/O pins it requires | |
38 | * are used for other purposes. | |
39 | * | |
40 | * platform_device->driver_data ... points to spi_gpio | |
41 | * | |
42 | * spi->controller_state ... reserved for bitbang framework code | |
43 | * spi->controller_data ... holds chipselect GPIO | |
44 | * | |
45 | * spi->master->dev.driver_data ... points to spi_gpio->bitbang | |
46 | */ | |
47 | ||
48 | struct spi_gpio { | |
49 | struct spi_bitbang bitbang; | |
50 | struct spi_gpio_platform_data pdata; | |
51 | struct platform_device *pdev; | |
161c2dd3 | 52 | int cs_gpios[0]; |
d29389de DB |
53 | }; |
54 | ||
55 | /*----------------------------------------------------------------------*/ | |
56 | ||
57 | /* | |
58 | * Because the overhead of going through four GPIO procedure calls | |
59 | * per transferred bit can make performance a problem, this code | |
60 | * is set up so that you can use it in either of two ways: | |
61 | * | |
62 | * - The slow generic way: set up platform_data to hold the GPIO | |
63 | * numbers used for MISO/MOSI/SCK, and issue procedure calls for | |
64 | * each of them. This driver can handle several such busses. | |
65 | * | |
66 | * - The quicker inlined way: only helps with platform GPIO code | |
67 | * that inlines operations for constant GPIOs. This can give | |
68 | * you tight (fast!) inner loops, but each such bus needs a | |
69 | * new driver. You'll define a new C file, with Makefile and | |
70 | * Kconfig support; the C code can be a total of six lines: | |
71 | * | |
72 | * #define DRIVER_NAME "myboard_spi2" | |
73 | * #define SPI_MISO_GPIO 119 | |
74 | * #define SPI_MOSI_GPIO 120 | |
75 | * #define SPI_SCK_GPIO 121 | |
76 | * #define SPI_N_CHIPSEL 4 | |
ca632f55 | 77 | * #include "spi-gpio.c" |
d29389de DB |
78 | */ |
79 | ||
80 | #ifndef DRIVER_NAME | |
81 | #define DRIVER_NAME "spi_gpio" | |
82 | ||
83 | #define GENERIC_BITBANG /* vs tight inlines */ | |
84 | ||
85 | /* all functions referencing these symbols must define pdata */ | |
86 | #define SPI_MISO_GPIO ((pdata)->miso) | |
87 | #define SPI_MOSI_GPIO ((pdata)->mosi) | |
88 | #define SPI_SCK_GPIO ((pdata)->sck) | |
89 | ||
90 | #define SPI_N_CHIPSEL ((pdata)->num_chipselect) | |
91 | ||
92 | #endif | |
93 | ||
94 | /*----------------------------------------------------------------------*/ | |
95 | ||
161c2dd3 DM |
96 | static inline struct spi_gpio * __pure |
97 | spi_to_spi_gpio(const struct spi_device *spi) | |
d29389de DB |
98 | { |
99 | const struct spi_bitbang *bang; | |
161c2dd3 | 100 | struct spi_gpio *spi_gpio; |
d29389de DB |
101 | |
102 | bang = spi_master_get_devdata(spi->master); | |
103 | spi_gpio = container_of(bang, struct spi_gpio, bitbang); | |
161c2dd3 DM |
104 | return spi_gpio; |
105 | } | |
106 | ||
107 | static inline struct spi_gpio_platform_data * __pure | |
108 | spi_to_pdata(const struct spi_device *spi) | |
109 | { | |
110 | return &spi_to_spi_gpio(spi)->pdata; | |
d29389de DB |
111 | } |
112 | ||
113 | /* this is #defined to avoid unused-variable warnings when inlining */ | |
114 | #define pdata spi_to_pdata(spi) | |
115 | ||
116 | static inline void setsck(const struct spi_device *spi, int is_on) | |
117 | { | |
118 | gpio_set_value(SPI_SCK_GPIO, is_on); | |
119 | } | |
120 | ||
121 | static inline void setmosi(const struct spi_device *spi, int is_on) | |
122 | { | |
123 | gpio_set_value(SPI_MOSI_GPIO, is_on); | |
124 | } | |
125 | ||
126 | static inline int getmiso(const struct spi_device *spi) | |
127 | { | |
be50344e | 128 | return !!gpio_get_value(SPI_MISO_GPIO); |
d29389de DB |
129 | } |
130 | ||
131 | #undef pdata | |
132 | ||
133 | /* | |
134 | * NOTE: this clocks "as fast as we can". It "should" be a function of the | |
135 | * requested device clock. Software overhead means we usually have trouble | |
136 | * reaching even one Mbit/sec (except when we can inline bitops), so for now | |
137 | * we'll just assume we never need additional per-bit slowdowns. | |
138 | */ | |
139 | #define spidelay(nsecs) do {} while (0) | |
140 | ||
ca632f55 | 141 | #include "spi-bitbang-txrx.h" |
d29389de DB |
142 | |
143 | /* | |
144 | * These functions can leverage inline expansion of GPIO calls to shrink | |
145 | * costs for a txrx bit, often by factors of around ten (by instruction | |
146 | * count). That is particularly visible for larger word sizes, but helps | |
147 | * even with default 8-bit words. | |
148 | * | |
149 | * REVISIT overheads calling these functions for each word also have | |
150 | * significant performance costs. Having txrx_bufs() calls that inline | |
151 | * the txrx_word() logic would help performance, e.g. on larger blocks | |
152 | * used with flash storage or MMC/SD. There should also be ways to make | |
153 | * GCC be less stupid about reloading registers inside the I/O loops, | |
154 | * even without inlined GPIO calls; __attribute__((hot)) on GCC 4.3? | |
155 | */ | |
156 | ||
157 | static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi, | |
158 | unsigned nsecs, u32 word, u8 bits) | |
159 | { | |
04bb2a03 | 160 | return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); |
d29389de DB |
161 | } |
162 | ||
163 | static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi, | |
164 | unsigned nsecs, u32 word, u8 bits) | |
165 | { | |
04bb2a03 | 166 | return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits); |
d29389de DB |
167 | } |
168 | ||
169 | static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi, | |
170 | unsigned nsecs, u32 word, u8 bits) | |
171 | { | |
04bb2a03 | 172 | return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits); |
d29389de DB |
173 | } |
174 | ||
175 | static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi, | |
176 | unsigned nsecs, u32 word, u8 bits) | |
177 | { | |
04bb2a03 | 178 | return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits); |
d29389de DB |
179 | } |
180 | ||
3c8e1a84 MS |
181 | /* |
182 | * These functions do not call setmosi or getmiso if respective flag | |
183 | * (SPI_MASTER_NO_RX or SPI_MASTER_NO_TX) is set, so they are safe to | |
184 | * call when such pin is not present or defined in the controller. | |
185 | * A separate set of callbacks is defined to get highest possible | |
186 | * speed in the generic case (when both MISO and MOSI lines are | |
187 | * available), as optimiser will remove the checks when argument is | |
188 | * constant. | |
189 | */ | |
190 | ||
191 | static u32 spi_gpio_spec_txrx_word_mode0(struct spi_device *spi, | |
192 | unsigned nsecs, u32 word, u8 bits) | |
193 | { | |
194 | unsigned flags = spi->master->flags; | |
195 | return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); | |
196 | } | |
197 | ||
198 | static u32 spi_gpio_spec_txrx_word_mode1(struct spi_device *spi, | |
199 | unsigned nsecs, u32 word, u8 bits) | |
200 | { | |
201 | unsigned flags = spi->master->flags; | |
202 | return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); | |
203 | } | |
204 | ||
205 | static u32 spi_gpio_spec_txrx_word_mode2(struct spi_device *spi, | |
206 | unsigned nsecs, u32 word, u8 bits) | |
207 | { | |
208 | unsigned flags = spi->master->flags; | |
209 | return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); | |
210 | } | |
211 | ||
212 | static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi, | |
213 | unsigned nsecs, u32 word, u8 bits) | |
214 | { | |
215 | unsigned flags = spi->master->flags; | |
216 | return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); | |
217 | } | |
218 | ||
d29389de DB |
219 | /*----------------------------------------------------------------------*/ |
220 | ||
221 | static void spi_gpio_chipselect(struct spi_device *spi, int is_active) | |
222 | { | |
161c2dd3 DM |
223 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); |
224 | unsigned int cs = spi_gpio->cs_gpios[spi->chip_select]; | |
d29389de DB |
225 | |
226 | /* set initial clock polarity */ | |
227 | if (is_active) | |
228 | setsck(spi, spi->mode & SPI_CPOL); | |
229 | ||
bfb9bcdb MB |
230 | if (cs != SPI_GPIO_NO_CHIPSELECT) { |
231 | /* SPI is normally active-low */ | |
232 | gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); | |
233 | } | |
d29389de DB |
234 | } |
235 | ||
236 | static int spi_gpio_setup(struct spi_device *spi) | |
237 | { | |
38ab18ca | 238 | unsigned int cs; |
161c2dd3 DM |
239 | int status = 0; |
240 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); | |
38ab18ca | 241 | struct device_node *np = spi->master->dev.of_node; |
d29389de | 242 | |
38ab18ca DM |
243 | if (np) { |
244 | /* | |
245 | * In DT environments, the CS GPIOs have already been | |
246 | * initialized from the "cs-gpios" property of the node. | |
247 | */ | |
248 | cs = spi_gpio->cs_gpios[spi->chip_select]; | |
249 | } else { | |
250 | /* | |
251 | * ... otherwise, take it from spi->controller_data | |
252 | */ | |
253 | cs = (unsigned int) spi->controller_data; | |
254 | } | |
255 | ||
d29389de | 256 | if (!spi->controller_state) { |
bfb9bcdb MB |
257 | if (cs != SPI_GPIO_NO_CHIPSELECT) { |
258 | status = gpio_request(cs, dev_name(&spi->dev)); | |
259 | if (status) | |
260 | return status; | |
05644147 UKK |
261 | status = gpio_direction_output(cs, |
262 | !(spi->mode & SPI_CS_HIGH)); | |
bfb9bcdb | 263 | } |
d29389de | 264 | } |
161c2dd3 | 265 | if (!status) { |
38ab18ca | 266 | /* in case it was initialized from static board data */ |
161c2dd3 | 267 | spi_gpio->cs_gpios[spi->chip_select] = cs; |
6b8cc330 | 268 | status = spi_bitbang_setup(spi); |
161c2dd3 DM |
269 | } |
270 | ||
d29389de | 271 | if (status) { |
bfb9bcdb | 272 | if (!spi->controller_state && cs != SPI_GPIO_NO_CHIPSELECT) |
d29389de DB |
273 | gpio_free(cs); |
274 | } | |
275 | return status; | |
276 | } | |
277 | ||
278 | static void spi_gpio_cleanup(struct spi_device *spi) | |
279 | { | |
161c2dd3 DM |
280 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); |
281 | unsigned int cs = spi_gpio->cs_gpios[spi->chip_select]; | |
d29389de | 282 | |
bfb9bcdb MB |
283 | if (cs != SPI_GPIO_NO_CHIPSELECT) |
284 | gpio_free(cs); | |
d29389de DB |
285 | spi_bitbang_cleanup(spi); |
286 | } | |
287 | ||
fd4a319b | 288 | static int spi_gpio_alloc(unsigned pin, const char *label, bool is_in) |
d29389de DB |
289 | { |
290 | int value; | |
291 | ||
292 | value = gpio_request(pin, label); | |
293 | if (value == 0) { | |
294 | if (is_in) | |
295 | value = gpio_direction_input(pin); | |
296 | else | |
297 | value = gpio_direction_output(pin, 0); | |
298 | } | |
299 | return value; | |
300 | } | |
301 | ||
fd4a319b GL |
302 | static int spi_gpio_request(struct spi_gpio_platform_data *pdata, |
303 | const char *label, u16 *res_flags) | |
d29389de DB |
304 | { |
305 | int value; | |
306 | ||
307 | /* NOTE: SPI_*_GPIO symbols may reference "pdata" */ | |
308 | ||
3c8e1a84 MS |
309 | if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) { |
310 | value = spi_gpio_alloc(SPI_MOSI_GPIO, label, false); | |
311 | if (value) | |
312 | goto done; | |
313 | } else { | |
314 | /* HW configuration without MOSI pin */ | |
315 | *res_flags |= SPI_MASTER_NO_TX; | |
316 | } | |
d29389de | 317 | |
3c8e1a84 MS |
318 | if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) { |
319 | value = spi_gpio_alloc(SPI_MISO_GPIO, label, true); | |
320 | if (value) | |
321 | goto free_mosi; | |
322 | } else { | |
323 | /* HW configuration without MISO pin */ | |
324 | *res_flags |= SPI_MASTER_NO_RX; | |
325 | } | |
d29389de DB |
326 | |
327 | value = spi_gpio_alloc(SPI_SCK_GPIO, label, false); | |
328 | if (value) | |
329 | goto free_miso; | |
330 | ||
331 | goto done; | |
332 | ||
333 | free_miso: | |
3c8e1a84 MS |
334 | if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) |
335 | gpio_free(SPI_MISO_GPIO); | |
d29389de | 336 | free_mosi: |
3c8e1a84 MS |
337 | if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) |
338 | gpio_free(SPI_MOSI_GPIO); | |
d29389de DB |
339 | done: |
340 | return value; | |
341 | } | |
342 | ||
38ab18ca DM |
343 | #ifdef CONFIG_OF |
344 | static struct of_device_id spi_gpio_dt_ids[] = { | |
345 | { .compatible = "spi-gpio" }, | |
346 | {} | |
347 | }; | |
348 | MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids); | |
349 | ||
350 | static int spi_gpio_probe_dt(struct platform_device *pdev) | |
351 | { | |
352 | int ret; | |
353 | u32 tmp; | |
354 | struct spi_gpio_platform_data *pdata; | |
355 | struct device_node *np = pdev->dev.of_node; | |
356 | const struct of_device_id *of_id = | |
357 | of_match_device(spi_gpio_dt_ids, &pdev->dev); | |
358 | ||
359 | if (!of_id) | |
360 | return 0; | |
361 | ||
362 | pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); | |
363 | if (!pdata) | |
364 | return -ENOMEM; | |
365 | ||
0202a32d MR |
366 | ret = of_get_named_gpio(np, "gpio-sck", 0); |
367 | if (ret < 0) { | |
368 | dev_err(&pdev->dev, "gpio-sck property not found\n"); | |
369 | goto error_free; | |
370 | } | |
371 | pdata->sck = ret; | |
372 | ||
373 | ret = of_get_named_gpio(np, "gpio-miso", 0); | |
374 | if (ret < 0) { | |
375 | dev_info(&pdev->dev, "gpio-miso property not found, switching to no-rx mode\n"); | |
376 | pdata->miso = SPI_GPIO_NO_MISO; | |
377 | } else | |
378 | pdata->miso = ret; | |
379 | ||
380 | ret = of_get_named_gpio(np, "gpio-mosi", 0); | |
381 | if (ret < 0) { | |
382 | dev_info(&pdev->dev, "gpio-mosi property not found, switching to no-tx mode\n"); | |
383 | pdata->mosi = SPI_GPIO_NO_MOSI; | |
384 | } else | |
385 | pdata->mosi = ret; | |
38ab18ca DM |
386 | |
387 | ret = of_property_read_u32(np, "num-chipselects", &tmp); | |
388 | if (ret < 0) { | |
389 | dev_err(&pdev->dev, "num-chipselects property not found\n"); | |
390 | goto error_free; | |
391 | } | |
392 | ||
393 | pdata->num_chipselect = tmp; | |
394 | pdev->dev.platform_data = pdata; | |
395 | ||
396 | return 1; | |
397 | ||
398 | error_free: | |
399 | devm_kfree(&pdev->dev, pdata); | |
400 | return ret; | |
401 | } | |
402 | #else | |
ac2cb30b | 403 | static inline int spi_gpio_probe_dt(struct platform_device *pdev) |
38ab18ca DM |
404 | { |
405 | return 0; | |
406 | } | |
407 | #endif | |
408 | ||
fd4a319b | 409 | static int spi_gpio_probe(struct platform_device *pdev) |
d29389de DB |
410 | { |
411 | int status; | |
412 | struct spi_master *master; | |
413 | struct spi_gpio *spi_gpio; | |
414 | struct spi_gpio_platform_data *pdata; | |
3c8e1a84 | 415 | u16 master_flags = 0; |
38ab18ca DM |
416 | bool use_of = 0; |
417 | ||
418 | status = spi_gpio_probe_dt(pdev); | |
419 | if (status < 0) | |
420 | return status; | |
421 | if (status > 0) | |
422 | use_of = 1; | |
d29389de | 423 | |
8074cf06 | 424 | pdata = dev_get_platdata(&pdev->dev); |
d29389de DB |
425 | #ifdef GENERIC_BITBANG |
426 | if (!pdata || !pdata->num_chipselect) | |
427 | return -ENODEV; | |
428 | #endif | |
429 | ||
3c8e1a84 | 430 | status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags); |
d29389de DB |
431 | if (status < 0) |
432 | return status; | |
433 | ||
161c2dd3 DM |
434 | master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio) + |
435 | (sizeof(int) * SPI_N_CHIPSEL)); | |
d29389de DB |
436 | if (!master) { |
437 | status = -ENOMEM; | |
438 | goto gpio_free; | |
439 | } | |
440 | spi_gpio = spi_master_get_devdata(master); | |
441 | platform_set_drvdata(pdev, spi_gpio); | |
442 | ||
443 | spi_gpio->pdev = pdev; | |
444 | if (pdata) | |
445 | spi_gpio->pdata = *pdata; | |
446 | ||
24778be2 | 447 | master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); |
3c8e1a84 | 448 | master->flags = master_flags; |
d29389de DB |
449 | master->bus_num = pdev->id; |
450 | master->num_chipselect = SPI_N_CHIPSEL; | |
451 | master->setup = spi_gpio_setup; | |
452 | master->cleanup = spi_gpio_cleanup; | |
38ab18ca DM |
453 | #ifdef CONFIG_OF |
454 | master->dev.of_node = pdev->dev.of_node; | |
455 | ||
456 | if (use_of) { | |
457 | int i; | |
458 | struct device_node *np = pdev->dev.of_node; | |
459 | ||
460 | /* | |
461 | * In DT environments, take the CS GPIO from the "cs-gpios" | |
462 | * property of the node. | |
463 | */ | |
464 | ||
465 | for (i = 0; i < SPI_N_CHIPSEL; i++) | |
466 | spi_gpio->cs_gpios[i] = | |
467 | of_get_named_gpio(np, "cs-gpios", i); | |
468 | } | |
469 | #endif | |
d29389de | 470 | |
94c69f76 | 471 | spi_gpio->bitbang.master = master; |
d29389de | 472 | spi_gpio->bitbang.chipselect = spi_gpio_chipselect; |
3c8e1a84 | 473 | |
23699f98 | 474 | if ((master_flags & (SPI_MASTER_NO_TX | SPI_MASTER_NO_RX)) == 0) { |
3c8e1a84 MS |
475 | spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0; |
476 | spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1; | |
477 | spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2; | |
478 | spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3; | |
479 | } else { | |
480 | spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0; | |
481 | spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1; | |
482 | spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2; | |
483 | spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3; | |
484 | } | |
d29389de DB |
485 | spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer; |
486 | spi_gpio->bitbang.flags = SPI_CS_HIGH; | |
487 | ||
488 | status = spi_bitbang_start(&spi_gpio->bitbang); | |
489 | if (status < 0) { | |
d29389de | 490 | gpio_free: |
3c8e1a84 MS |
491 | if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) |
492 | gpio_free(SPI_MISO_GPIO); | |
493 | if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) | |
494 | gpio_free(SPI_MOSI_GPIO); | |
d29389de DB |
495 | gpio_free(SPI_SCK_GPIO); |
496 | spi_master_put(master); | |
497 | } | |
498 | ||
499 | return status; | |
500 | } | |
501 | ||
fd4a319b | 502 | static int spi_gpio_remove(struct platform_device *pdev) |
d29389de DB |
503 | { |
504 | struct spi_gpio *spi_gpio; | |
505 | struct spi_gpio_platform_data *pdata; | |
506 | int status; | |
507 | ||
508 | spi_gpio = platform_get_drvdata(pdev); | |
8074cf06 | 509 | pdata = dev_get_platdata(&pdev->dev); |
d29389de DB |
510 | |
511 | /* stop() unregisters child devices too */ | |
512 | status = spi_bitbang_stop(&spi_gpio->bitbang); | |
d29389de | 513 | |
3c8e1a84 MS |
514 | if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) |
515 | gpio_free(SPI_MISO_GPIO); | |
516 | if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) | |
517 | gpio_free(SPI_MOSI_GPIO); | |
d29389de | 518 | gpio_free(SPI_SCK_GPIO); |
94c69f76 | 519 | spi_master_put(spi_gpio->bitbang.master); |
d29389de DB |
520 | |
521 | return status; | |
522 | } | |
523 | ||
524 | MODULE_ALIAS("platform:" DRIVER_NAME); | |
525 | ||
526 | static struct platform_driver spi_gpio_driver = { | |
38ab18ca DM |
527 | .driver = { |
528 | .name = DRIVER_NAME, | |
529 | .owner = THIS_MODULE, | |
530 | .of_match_table = of_match_ptr(spi_gpio_dt_ids), | |
531 | }, | |
940ab889 | 532 | .probe = spi_gpio_probe, |
fd4a319b | 533 | .remove = spi_gpio_remove, |
d29389de | 534 | }; |
940ab889 | 535 | module_platform_driver(spi_gpio_driver); |
d29389de DB |
536 | |
537 | MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO "); | |
538 | MODULE_AUTHOR("David Brownell"); | |
539 | MODULE_LICENSE("GPL"); |