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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
Manuel Laussc65b53b2011-11-19 13:08:10 +0100290static int __devinit 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
Manuel Laussc65b53b2011-11-19 13:08:10 +0100304static int __devinit
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600305spi_gpio_request(struct spi_gpio_platform_data *pdata, const char *label,
306 u16 *res_flags)
David Brownelld29389d2009-01-06 14:41:41 -0800307{
308 int value;
309
310 /* NOTE: SPI_*_GPIO symbols may reference "pdata" */
311
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600312 if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) {
313 value = spi_gpio_alloc(SPI_MOSI_GPIO, label, false);
314 if (value)
315 goto done;
316 } else {
317 /* HW configuration without MOSI pin */
318 *res_flags |= SPI_MASTER_NO_TX;
319 }
David Brownelld29389d2009-01-06 14:41:41 -0800320
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600321 if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) {
322 value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
323 if (value)
324 goto free_mosi;
325 } else {
326 /* HW configuration without MISO pin */
327 *res_flags |= SPI_MASTER_NO_RX;
328 }
David Brownelld29389d2009-01-06 14:41:41 -0800329
330 value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
331 if (value)
332 goto free_miso;
333
334 goto done;
335
336free_miso:
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600337 if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
338 gpio_free(SPI_MISO_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800339free_mosi:
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600340 if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
341 gpio_free(SPI_MOSI_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800342done:
343 return value;
344}
345
Daniel Mack38ab18c2012-09-05 11:04:36 +0200346#ifdef CONFIG_OF
347static struct of_device_id spi_gpio_dt_ids[] = {
348 { .compatible = "spi-gpio" },
349 {}
350};
351MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids);
352
353static int spi_gpio_probe_dt(struct platform_device *pdev)
354{
355 int ret;
356 u32 tmp;
357 struct spi_gpio_platform_data *pdata;
358 struct device_node *np = pdev->dev.of_node;
359 const struct of_device_id *of_id =
360 of_match_device(spi_gpio_dt_ids, &pdev->dev);
361
362 if (!of_id)
363 return 0;
364
365 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
366 if (!pdata)
367 return -ENOMEM;
368
369 pdata->sck = of_get_named_gpio(np, "gpio-sck", 0);
370 pdata->miso = of_get_named_gpio(np, "gpio-miso", 0);
371 pdata->mosi = of_get_named_gpio(np, "gpio-mosi", 0);
372
373 ret = of_property_read_u32(np, "num-chipselects", &tmp);
374 if (ret < 0) {
375 dev_err(&pdev->dev, "num-chipselects property not found\n");
376 goto error_free;
377 }
378
379 pdata->num_chipselect = tmp;
380 pdev->dev.platform_data = pdata;
381
382 return 1;
383
384error_free:
385 devm_kfree(&pdev->dev, pdata);
386 return ret;
387}
388#else
389static inline int spi_probe_dt(struct platform_device *)
390{
391 return 0;
392}
393#endif
394
Grant Likely940ab882011-10-05 11:29:49 -0600395static int __devinit spi_gpio_probe(struct platform_device *pdev)
David Brownelld29389d2009-01-06 14:41:41 -0800396{
397 int status;
398 struct spi_master *master;
399 struct spi_gpio *spi_gpio;
400 struct spi_gpio_platform_data *pdata;
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600401 u16 master_flags = 0;
Daniel Mack38ab18c2012-09-05 11:04:36 +0200402 bool use_of = 0;
403
404 status = spi_gpio_probe_dt(pdev);
405 if (status < 0)
406 return status;
407 if (status > 0)
408 use_of = 1;
David Brownelld29389d2009-01-06 14:41:41 -0800409
410 pdata = pdev->dev.platform_data;
411#ifdef GENERIC_BITBANG
412 if (!pdata || !pdata->num_chipselect)
413 return -ENODEV;
414#endif
415
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600416 status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags);
David Brownelld29389d2009-01-06 14:41:41 -0800417 if (status < 0)
418 return status;
419
Daniel Mack161c2dd2012-09-05 11:04:35 +0200420 master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio) +
421 (sizeof(int) * SPI_N_CHIPSEL));
David Brownelld29389d2009-01-06 14:41:41 -0800422 if (!master) {
423 status = -ENOMEM;
424 goto gpio_free;
425 }
426 spi_gpio = spi_master_get_devdata(master);
427 platform_set_drvdata(pdev, spi_gpio);
428
429 spi_gpio->pdev = pdev;
430 if (pdata)
431 spi_gpio->pdata = *pdata;
432
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600433 master->flags = master_flags;
David Brownelld29389d2009-01-06 14:41:41 -0800434 master->bus_num = pdev->id;
435 master->num_chipselect = SPI_N_CHIPSEL;
436 master->setup = spi_gpio_setup;
437 master->cleanup = spi_gpio_cleanup;
Daniel Mack38ab18c2012-09-05 11:04:36 +0200438#ifdef CONFIG_OF
439 master->dev.of_node = pdev->dev.of_node;
440
441 if (use_of) {
442 int i;
443 struct device_node *np = pdev->dev.of_node;
444
445 /*
446 * In DT environments, take the CS GPIO from the "cs-gpios"
447 * property of the node.
448 */
449
450 for (i = 0; i < SPI_N_CHIPSEL; i++)
451 spi_gpio->cs_gpios[i] =
452 of_get_named_gpio(np, "cs-gpios", i);
453 }
454#endif
David Brownelld29389d2009-01-06 14:41:41 -0800455
456 spi_gpio->bitbang.master = spi_master_get(master);
457 spi_gpio->bitbang.chipselect = spi_gpio_chipselect;
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600458
Roel Kluin23699f92010-10-02 14:03:32 +0200459 if ((master_flags & (SPI_MASTER_NO_TX | SPI_MASTER_NO_RX)) == 0) {
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600460 spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0;
461 spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1;
462 spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
463 spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
464 } else {
465 spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0;
466 spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1;
467 spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2;
468 spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3;
469 }
David Brownelld29389d2009-01-06 14:41:41 -0800470 spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
471 spi_gpio->bitbang.flags = SPI_CS_HIGH;
472
473 status = spi_bitbang_start(&spi_gpio->bitbang);
474 if (status < 0) {
475 spi_master_put(spi_gpio->bitbang.master);
476gpio_free:
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600477 if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
478 gpio_free(SPI_MISO_GPIO);
479 if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
480 gpio_free(SPI_MOSI_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800481 gpio_free(SPI_SCK_GPIO);
482 spi_master_put(master);
483 }
484
485 return status;
486}
487
Grant Likely940ab882011-10-05 11:29:49 -0600488static int __devexit spi_gpio_remove(struct platform_device *pdev)
David Brownelld29389d2009-01-06 14:41:41 -0800489{
490 struct spi_gpio *spi_gpio;
491 struct spi_gpio_platform_data *pdata;
492 int status;
493
494 spi_gpio = platform_get_drvdata(pdev);
495 pdata = pdev->dev.platform_data;
496
497 /* stop() unregisters child devices too */
498 status = spi_bitbang_stop(&spi_gpio->bitbang);
499 spi_master_put(spi_gpio->bitbang.master);
500
501 platform_set_drvdata(pdev, NULL);
502
Marek Szyprowski3c8e1a82010-06-30 14:27:37 -0600503 if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO)
504 gpio_free(SPI_MISO_GPIO);
505 if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI)
506 gpio_free(SPI_MOSI_GPIO);
David Brownelld29389d2009-01-06 14:41:41 -0800507 gpio_free(SPI_SCK_GPIO);
508
509 return status;
510}
511
512MODULE_ALIAS("platform:" DRIVER_NAME);
513
514static struct platform_driver spi_gpio_driver = {
Daniel Mack38ab18c2012-09-05 11:04:36 +0200515 .driver = {
516 .name = DRIVER_NAME,
517 .owner = THIS_MODULE,
518 .of_match_table = of_match_ptr(spi_gpio_dt_ids),
519 },
Grant Likely940ab882011-10-05 11:29:49 -0600520 .probe = spi_gpio_probe,
521 .remove = __devexit_p(spi_gpio_remove),
David Brownelld29389d2009-01-06 14:41:41 -0800522};
Grant Likely940ab882011-10-05 11:29:49 -0600523module_platform_driver(spi_gpio_driver);
David Brownelld29389d2009-01-06 14:41:41 -0800524
525MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO ");
526MODULE_AUTHOR("David Brownell");
527MODULE_LICENSE("GPL");