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David Brownelld29389d2009-01-06 14:41:41 -08001/*
Grant Likelyca632f52011-06-06 01:16:30 -06002 * SPI master driver using generic bitbanged GPIO
David Brownelld29389d2009-01-06 14:41:41 -08003 *
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>
Paul Gortmakerd7614de2011-07-03 15:44:29 -040021#include <linux/module.h>
David Brownelld29389d2009-01-06 14:41:41 -080022#include <linux/init.h>
23#include <linux/platform_device.h>
24#include <linux/gpio.h>
Daniel Mack38ab18c2012-09-05 11:04:36 +020025#include <linux/of_device.h>
26#include <linux/of_gpio.h>
David Brownelld29389d2009-01-06 14:41:41 -080027
28#include <linux/spi/spi.h>
29#include <linux/spi/spi_bitbang.h>
30#include <linux/spi/spi_gpio.h>
31
32
33/*
34 * This bitbanging SPI master driver should help make systems usable
35 * when a native hardware SPI engine is not available, perhaps because
36 * its driver isn't yet working or because the I/O pins it requires
37 * are used for other purposes.
38 *
39 * platform_device->driver_data ... points to spi_gpio
40 *
41 * spi->controller_state ... reserved for bitbang framework code
42 * spi->controller_data ... holds chipselect GPIO
43 *
44 * spi->master->dev.driver_data ... points to spi_gpio->bitbang
45 */
46
47struct spi_gpio {
48 struct spi_bitbang bitbang;
49 struct spi_gpio_platform_data pdata;
50 struct platform_device *pdev;
Daniel Mack161c2dd2012-09-05 11:04:35 +020051 int cs_gpios[0];
David Brownelld29389d2009-01-06 14:41:41 -080052};
53
54/*----------------------------------------------------------------------*/
55
56/*
57 * Because the overhead of going through four GPIO procedure calls
58 * per transferred bit can make performance a problem, this code
59 * is set up so that you can use it in either of two ways:
60 *
61 * - The slow generic way: set up platform_data to hold the GPIO
62 * numbers used for MISO/MOSI/SCK, and issue procedure calls for
63 * each of them. This driver can handle several such busses.
64 *
65 * - The quicker inlined way: only helps with platform GPIO code
66 * that inlines operations for constant GPIOs. This can give
67 * you tight (fast!) inner loops, but each such bus needs a
68 * new driver. You'll define a new C file, with Makefile and
69 * Kconfig support; the C code can be a total of six lines:
70 *
71 * #define DRIVER_NAME "myboard_spi2"
72 * #define SPI_MISO_GPIO 119
73 * #define SPI_MOSI_GPIO 120
74 * #define SPI_SCK_GPIO 121
75 * #define SPI_N_CHIPSEL 4
Grant Likelyca632f52011-06-06 01:16:30 -060076 * #include "spi-gpio.c"
David Brownelld29389d2009-01-06 14:41:41 -080077 */
78
79#ifndef DRIVER_NAME
80#define DRIVER_NAME "spi_gpio"
81
82#define GENERIC_BITBANG /* vs tight inlines */
83
84/* all functions referencing these symbols must define pdata */
85#define SPI_MISO_GPIO ((pdata)->miso)
86#define SPI_MOSI_GPIO ((pdata)->mosi)
87#define SPI_SCK_GPIO ((pdata)->sck)
88
89#define SPI_N_CHIPSEL ((pdata)->num_chipselect)
90
91#endif
92
93/*----------------------------------------------------------------------*/
94
Daniel Mack161c2dd2012-09-05 11:04:35 +020095static inline struct spi_gpio * __pure
96spi_to_spi_gpio(const struct spi_device *spi)
David Brownelld29389d2009-01-06 14:41:41 -080097{
98 const struct spi_bitbang *bang;
Daniel Mack161c2dd2012-09-05 11:04:35 +020099 struct spi_gpio *spi_gpio;
David Brownelld29389d2009-01-06 14:41:41 -0800100
101 bang = spi_master_get_devdata(spi->master);
102 spi_gpio = container_of(bang, struct spi_gpio, bitbang);
Daniel Mack161c2dd2012-09-05 11:04:35 +0200103 return spi_gpio;
104}
105
106static inline struct spi_gpio_platform_data * __pure
107spi_to_pdata(const struct spi_device *spi)
108{
109 return &spi_to_spi_gpio(spi)->pdata;
David Brownelld29389d2009-01-06 14:41:41 -0800110}
111
112/* this is #defined to avoid unused-variable warnings when inlining */
113#define pdata spi_to_pdata(spi)
114
115static inline void setsck(const struct spi_device *spi, int is_on)
116{
117 gpio_set_value(SPI_SCK_GPIO, is_on);
118}
119
120static inline void setmosi(const struct spi_device *spi, int is_on)
121{
122 gpio_set_value(SPI_MOSI_GPIO, is_on);
123}
124
125static inline int getmiso(const struct spi_device *spi)
126{
Michael Bueschbe503442009-02-18 14:48:41 -0800127 return !!gpio_get_value(SPI_MISO_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800128}
129
130#undef pdata
131
132/*
133 * NOTE: this clocks "as fast as we can". It "should" be a function of the
134 * requested device clock. Software overhead means we usually have trouble
135 * reaching even one Mbit/sec (except when we can inline bitops), so for now
136 * we'll just assume we never need additional per-bit slowdowns.
137 */
138#define spidelay(nsecs) do {} while (0)
139
Grant Likelyca632f52011-06-06 01:16:30 -0600140#include "spi-bitbang-txrx.h"
David Brownelld29389d2009-01-06 14:41:41 -0800141
142/*
143 * These functions can leverage inline expansion of GPIO calls to shrink
144 * costs for a txrx bit, often by factors of around ten (by instruction
145 * count). That is particularly visible for larger word sizes, but helps
146 * even with default 8-bit words.
147 *
148 * REVISIT overheads calling these functions for each word also have
149 * significant performance costs. Having txrx_bufs() calls that inline
150 * the txrx_word() logic would help performance, e.g. on larger blocks
151 * used with flash storage or MMC/SD. There should also be ways to make
152 * GCC be less stupid about reloading registers inside the I/O loops,
153 * even without inlined GPIO calls; __attribute__((hot)) on GCC 4.3?
154 */
155
156static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi,
157 unsigned nsecs, u32 word, u8 bits)
158{
Marek Szyprowski04bb2a02010-06-30 14:27:32 -0600159 return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
David Brownelld29389d2009-01-06 14:41:41 -0800160}
161
162static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi,
163 unsigned nsecs, u32 word, u8 bits)
164{
Marek Szyprowski04bb2a02010-06-30 14:27:32 -0600165 return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
David Brownelld29389d2009-01-06 14:41:41 -0800166}
167
168static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi,
169 unsigned nsecs, u32 word, u8 bits)
170{
Marek Szyprowski04bb2a02010-06-30 14:27:32 -0600171 return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
David Brownelld29389d2009-01-06 14:41:41 -0800172}
173
174static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi,
175 unsigned nsecs, u32 word, u8 bits)
176{
Marek Szyprowski04bb2a02010-06-30 14:27:32 -0600177 return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
David Brownelld29389d2009-01-06 14:41:41 -0800178}
179
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600180/*
181 * These functions do not call setmosi or getmiso if respective flag
182 * (SPI_MASTER_NO_RX or SPI_MASTER_NO_TX) is set, so they are safe to
183 * call when such pin is not present or defined in the controller.
184 * A separate set of callbacks is defined to get highest possible
185 * speed in the generic case (when both MISO and MOSI lines are
186 * available), as optimiser will remove the checks when argument is
187 * constant.
188 */
189
190static u32 spi_gpio_spec_txrx_word_mode0(struct spi_device *spi,
191 unsigned nsecs, u32 word, u8 bits)
192{
193 unsigned flags = spi->master->flags;
194 return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits);
195}
196
197static u32 spi_gpio_spec_txrx_word_mode1(struct spi_device *spi,
198 unsigned nsecs, u32 word, u8 bits)
199{
200 unsigned flags = spi->master->flags;
201 return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits);
202}
203
204static u32 spi_gpio_spec_txrx_word_mode2(struct spi_device *spi,
205 unsigned nsecs, u32 word, u8 bits)
206{
207 unsigned flags = spi->master->flags;
208 return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits);
209}
210
211static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi,
212 unsigned nsecs, u32 word, u8 bits)
213{
214 unsigned flags = spi->master->flags;
215 return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits);
216}
217
David Brownelld29389d2009-01-06 14:41:41 -0800218/*----------------------------------------------------------------------*/
219
220static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
221{
Daniel Mack161c2dd2012-09-05 11:04:35 +0200222 struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
223 unsigned int cs = spi_gpio->cs_gpios[spi->chip_select];
David Brownelld29389d2009-01-06 14:41:41 -0800224
225 /* set initial clock polarity */
226 if (is_active)
227 setsck(spi, spi->mode & SPI_CPOL);
228
Michael Bueschbfb9bcd2009-04-02 16:57:07 -0700229 if (cs != SPI_GPIO_NO_CHIPSELECT) {
230 /* SPI is normally active-low */
231 gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
232 }
David Brownelld29389d2009-01-06 14:41:41 -0800233}
234
235static int spi_gpio_setup(struct spi_device *spi)
236{
Daniel Mack38ab18c2012-09-05 11:04:36 +0200237 unsigned int cs;
Daniel Mack161c2dd2012-09-05 11:04:35 +0200238 int status = 0;
239 struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
Daniel Mack38ab18c2012-09-05 11:04:36 +0200240 struct device_node *np = spi->master->dev.of_node;
David Brownelld29389d2009-01-06 14:41:41 -0800241
242 if (spi->bits_per_word > 32)
243 return -EINVAL;
244
Daniel Mack38ab18c2012-09-05 11:04:36 +0200245 if (np) {
246 /*
247 * In DT environments, the CS GPIOs have already been
248 * initialized from the "cs-gpios" property of the node.
249 */
250 cs = spi_gpio->cs_gpios[spi->chip_select];
251 } else {
252 /*
253 * ... otherwise, take it from spi->controller_data
254 */
255 cs = (unsigned int) spi->controller_data;
256 }
257
David Brownelld29389d2009-01-06 14:41:41 -0800258 if (!spi->controller_state) {
Michael Bueschbfb9bcd2009-04-02 16:57:07 -0700259 if (cs != SPI_GPIO_NO_CHIPSELECT) {
260 status = gpio_request(cs, dev_name(&spi->dev));
261 if (status)
262 return status;
Uwe Kleine-König05644142012-02-09 22:21:45 +0100263 status = gpio_direction_output(cs,
264 !(spi->mode & SPI_CS_HIGH));
Michael Bueschbfb9bcd2009-04-02 16:57:07 -0700265 }
David Brownelld29389d2009-01-06 14:41:41 -0800266 }
Daniel Mack161c2dd2012-09-05 11:04:35 +0200267 if (!status) {
David Brownelld29389d2009-01-06 14:41:41 -0800268 status = spi_bitbang_setup(spi);
Daniel Mack38ab18c2012-09-05 11:04:36 +0200269 /* in case it was initialized from static board data */
Daniel Mack161c2dd2012-09-05 11:04:35 +0200270 spi_gpio->cs_gpios[spi->chip_select] = cs;
271 }
272
David Brownelld29389d2009-01-06 14:41:41 -0800273 if (status) {
Michael Bueschbfb9bcd2009-04-02 16:57:07 -0700274 if (!spi->controller_state && cs != SPI_GPIO_NO_CHIPSELECT)
David Brownelld29389d2009-01-06 14:41:41 -0800275 gpio_free(cs);
276 }
277 return status;
278}
279
280static void spi_gpio_cleanup(struct spi_device *spi)
281{
Daniel Mack161c2dd2012-09-05 11:04:35 +0200282 struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
283 unsigned int cs = spi_gpio->cs_gpios[spi->chip_select];
David Brownelld29389d2009-01-06 14:41:41 -0800284
Michael Bueschbfb9bcd2009-04-02 16:57:07 -0700285 if (cs != SPI_GPIO_NO_CHIPSELECT)
286 gpio_free(cs);
David Brownelld29389d2009-01-06 14:41:41 -0800287 spi_bitbang_cleanup(spi);
288}
289
Grant Likelyfd4a3192012-12-07 16:57:14 +0000290static int spi_gpio_alloc(unsigned pin, const char *label, bool is_in)
David Brownelld29389d2009-01-06 14:41:41 -0800291{
292 int value;
293
294 value = gpio_request(pin, label);
295 if (value == 0) {
296 if (is_in)
297 value = gpio_direction_input(pin);
298 else
299 value = gpio_direction_output(pin, 0);
300 }
301 return value;
302}
303
Grant Likelyfd4a3192012-12-07 16:57:14 +0000304static int spi_gpio_request(struct spi_gpio_platform_data *pdata,
305 const char *label, u16 *res_flags)
David Brownelld29389d2009-01-06 14:41:41 -0800306{
307 int value;
308
309 /* NOTE: SPI_*_GPIO symbols may reference "pdata" */
310
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600311 if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) {
312 value = spi_gpio_alloc(SPI_MOSI_GPIO, label, false);
313 if (value)
314 goto done;
315 } else {
316 /* HW configuration without MOSI pin */
317 *res_flags |= SPI_MASTER_NO_TX;
318 }
David Brownelld29389d2009-01-06 14:41:41 -0800319
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600320 if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) {
321 value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
322 if (value)
323 goto free_mosi;
324 } else {
325 /* HW configuration without MISO pin */
326 *res_flags |= SPI_MASTER_NO_RX;
327 }
David Brownelld29389d2009-01-06 14:41:41 -0800328
329 value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
330 if (value)
331 goto free_miso;
332
333 goto done;
334
335free_miso:
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600336 if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
337 gpio_free(SPI_MISO_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800338free_mosi:
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600339 if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
340 gpio_free(SPI_MOSI_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800341done:
342 return value;
343}
344
Daniel Mack38ab18c2012-09-05 11:04:36 +0200345#ifdef CONFIG_OF
346static struct of_device_id spi_gpio_dt_ids[] = {
347 { .compatible = "spi-gpio" },
348 {}
349};
350MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids);
351
352static int spi_gpio_probe_dt(struct platform_device *pdev)
353{
354 int ret;
355 u32 tmp;
356 struct spi_gpio_platform_data *pdata;
357 struct device_node *np = pdev->dev.of_node;
358 const struct of_device_id *of_id =
359 of_match_device(spi_gpio_dt_ids, &pdev->dev);
360
361 if (!of_id)
362 return 0;
363
364 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
365 if (!pdata)
366 return -ENOMEM;
367
368 pdata->sck = of_get_named_gpio(np, "gpio-sck", 0);
369 pdata->miso = of_get_named_gpio(np, "gpio-miso", 0);
370 pdata->mosi = of_get_named_gpio(np, "gpio-mosi", 0);
371
372 ret = of_property_read_u32(np, "num-chipselects", &tmp);
373 if (ret < 0) {
374 dev_err(&pdev->dev, "num-chipselects property not found\n");
375 goto error_free;
376 }
377
378 pdata->num_chipselect = tmp;
379 pdev->dev.platform_data = pdata;
380
381 return 1;
382
383error_free:
384 devm_kfree(&pdev->dev, pdata);
385 return ret;
386}
387#else
Mark Brownac2cb302012-09-07 08:23:06 +0800388static inline int spi_gpio_probe_dt(struct platform_device *pdev)
Daniel Mack38ab18c2012-09-05 11:04:36 +0200389{
390 return 0;
391}
392#endif
393
Grant Likelyfd4a3192012-12-07 16:57:14 +0000394static int spi_gpio_probe(struct platform_device *pdev)
David Brownelld29389d2009-01-06 14:41:41 -0800395{
396 int status;
397 struct spi_master *master;
398 struct spi_gpio *spi_gpio;
399 struct spi_gpio_platform_data *pdata;
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600400 u16 master_flags = 0;
Daniel Mack38ab18c2012-09-05 11:04:36 +0200401 bool use_of = 0;
402
403 status = spi_gpio_probe_dt(pdev);
404 if (status < 0)
405 return status;
406 if (status > 0)
407 use_of = 1;
David Brownelld29389d2009-01-06 14:41:41 -0800408
409 pdata = pdev->dev.platform_data;
410#ifdef GENERIC_BITBANG
411 if (!pdata || !pdata->num_chipselect)
412 return -ENODEV;
413#endif
414
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600415 status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags);
David Brownelld29389d2009-01-06 14:41:41 -0800416 if (status < 0)
417 return status;
418
Daniel Mack161c2dd2012-09-05 11:04:35 +0200419 master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio) +
420 (sizeof(int) * SPI_N_CHIPSEL));
David Brownelld29389d2009-01-06 14:41:41 -0800421 if (!master) {
422 status = -ENOMEM;
423 goto gpio_free;
424 }
425 spi_gpio = spi_master_get_devdata(master);
426 platform_set_drvdata(pdev, spi_gpio);
427
428 spi_gpio->pdev = pdev;
429 if (pdata)
430 spi_gpio->pdata = *pdata;
431
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600432 master->flags = master_flags;
David Brownelld29389d2009-01-06 14:41:41 -0800433 master->bus_num = pdev->id;
434 master->num_chipselect = SPI_N_CHIPSEL;
435 master->setup = spi_gpio_setup;
436 master->cleanup = spi_gpio_cleanup;
Daniel Mack38ab18c2012-09-05 11:04:36 +0200437#ifdef CONFIG_OF
438 master->dev.of_node = pdev->dev.of_node;
439
440 if (use_of) {
441 int i;
442 struct device_node *np = pdev->dev.of_node;
443
444 /*
445 * In DT environments, take the CS GPIO from the "cs-gpios"
446 * property of the node.
447 */
448
449 for (i = 0; i < SPI_N_CHIPSEL; i++)
450 spi_gpio->cs_gpios[i] =
451 of_get_named_gpio(np, "cs-gpios", i);
452 }
453#endif
David Brownelld29389d2009-01-06 14:41:41 -0800454
455 spi_gpio->bitbang.master = spi_master_get(master);
456 spi_gpio->bitbang.chipselect = spi_gpio_chipselect;
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600457
Roel Kluin23699f92010-10-02 14:03:32 +0200458 if ((master_flags & (SPI_MASTER_NO_TX | SPI_MASTER_NO_RX)) == 0) {
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600459 spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0;
460 spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1;
461 spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
462 spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
463 } else {
464 spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0;
465 spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1;
466 spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2;
467 spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3;
468 }
David Brownelld29389d2009-01-06 14:41:41 -0800469 spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
470 spi_gpio->bitbang.flags = SPI_CS_HIGH;
471
472 status = spi_bitbang_start(&spi_gpio->bitbang);
473 if (status < 0) {
474 spi_master_put(spi_gpio->bitbang.master);
475gpio_free:
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600476 if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
477 gpio_free(SPI_MISO_GPIO);
478 if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
479 gpio_free(SPI_MOSI_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800480 gpio_free(SPI_SCK_GPIO);
481 spi_master_put(master);
482 }
483
484 return status;
485}
486
Grant Likelyfd4a3192012-12-07 16:57:14 +0000487static int spi_gpio_remove(struct platform_device *pdev)
David Brownelld29389d2009-01-06 14:41:41 -0800488{
489 struct spi_gpio *spi_gpio;
490 struct spi_gpio_platform_data *pdata;
491 int status;
492
493 spi_gpio = platform_get_drvdata(pdev);
494 pdata = pdev->dev.platform_data;
495
496 /* stop() unregisters child devices too */
497 status = spi_bitbang_stop(&spi_gpio->bitbang);
498 spi_master_put(spi_gpio->bitbang.master);
499
500 platform_set_drvdata(pdev, NULL);
501
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600502 if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
503 gpio_free(SPI_MISO_GPIO);
504 if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
505 gpio_free(SPI_MOSI_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800506 gpio_free(SPI_SCK_GPIO);
507
508 return status;
509}
510
511MODULE_ALIAS("platform:" DRIVER_NAME);
512
513static struct platform_driver spi_gpio_driver = {
Daniel Mack38ab18c2012-09-05 11:04:36 +0200514 .driver = {
515 .name = DRIVER_NAME,
516 .owner = THIS_MODULE,
517 .of_match_table = of_match_ptr(spi_gpio_dt_ids),
518 },
Grant Likely940ab882011-10-05 11:29:49 -0600519 .probe = spi_gpio_probe,
Grant Likelyfd4a3192012-12-07 16:57:14 +0000520 .remove = spi_gpio_remove,
David Brownelld29389d2009-01-06 14:41:41 -0800521};
Grant Likely940ab882011-10-05 11:29:49 -0600522module_platform_driver(spi_gpio_driver);
David Brownelld29389d2009-01-06 14:41:41 -0800523
524MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO ");
525MODULE_AUTHOR("David Brownell");
526MODULE_LICENSE("GPL");