Commit | Line | Data |
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d29389de | 1 | /* |
ca632f55 | 2 | * SPI master driver using generic bitbanged GPIO |
d29389de DB |
3 | * |
4 | * Copyright (C) 2006,2008 David Brownell | |
9b00bc7b | 5 | * Copyright (C) 2017 Linus Walleij |
d29389de DB |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
d29389de DB |
16 | */ |
17 | #include <linux/kernel.h> | |
d7614de4 | 18 | #include <linux/module.h> |
d29389de | 19 | #include <linux/platform_device.h> |
9b00bc7b | 20 | #include <linux/gpio/consumer.h> |
ecc77773 | 21 | #include <linux/of.h> |
38ab18ca | 22 | #include <linux/of_device.h> |
d29389de DB |
23 | |
24 | #include <linux/spi/spi.h> | |
25 | #include <linux/spi/spi_bitbang.h> | |
26 | #include <linux/spi/spi_gpio.h> | |
27 | ||
28 | ||
29 | /* | |
30 | * This bitbanging SPI master driver should help make systems usable | |
31 | * when a native hardware SPI engine is not available, perhaps because | |
32 | * its driver isn't yet working or because the I/O pins it requires | |
33 | * are used for other purposes. | |
34 | * | |
35 | * platform_device->driver_data ... points to spi_gpio | |
36 | * | |
37 | * spi->controller_state ... reserved for bitbang framework code | |
38 | * spi->controller_data ... holds chipselect GPIO | |
39 | * | |
40 | * spi->master->dev.driver_data ... points to spi_gpio->bitbang | |
41 | */ | |
42 | ||
43 | struct spi_gpio { | |
44 | struct spi_bitbang bitbang; | |
45 | struct spi_gpio_platform_data pdata; | |
46 | struct platform_device *pdev; | |
9b00bc7b LW |
47 | struct gpio_desc *sck; |
48 | struct gpio_desc *miso; | |
49 | struct gpio_desc *mosi; | |
50 | struct gpio_desc **cs_gpios; | |
51 | bool has_cs; | |
d29389de DB |
52 | }; |
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 | |
ca632f55 | 76 | * #include "spi-gpio.c" |
d29389de DB |
77 | */ |
78 | ||
79 | #ifndef DRIVER_NAME | |
80 | #define DRIVER_NAME "spi_gpio" | |
81 | ||
82 | #define GENERIC_BITBANG /* vs tight inlines */ | |
83 | ||
d29389de DB |
84 | #endif |
85 | ||
86 | /*----------------------------------------------------------------------*/ | |
87 | ||
650705cf | 88 | static inline struct spi_gpio *__pure |
161c2dd3 | 89 | spi_to_spi_gpio(const struct spi_device *spi) |
d29389de DB |
90 | { |
91 | const struct spi_bitbang *bang; | |
161c2dd3 | 92 | struct spi_gpio *spi_gpio; |
d29389de DB |
93 | |
94 | bang = spi_master_get_devdata(spi->master); | |
95 | spi_gpio = container_of(bang, struct spi_gpio, bitbang); | |
161c2dd3 DM |
96 | return spi_gpio; |
97 | } | |
98 | ||
650705cf | 99 | static inline struct spi_gpio_platform_data *__pure |
161c2dd3 DM |
100 | spi_to_pdata(const struct spi_device *spi) |
101 | { | |
102 | return &spi_to_spi_gpio(spi)->pdata; | |
d29389de DB |
103 | } |
104 | ||
9b00bc7b | 105 | /* These helpers are in turn called by the bitbang inlines */ |
d29389de DB |
106 | static inline void setsck(const struct spi_device *spi, int is_on) |
107 | { | |
9b00bc7b LW |
108 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); |
109 | ||
110 | gpiod_set_value_cansleep(spi_gpio->sck, is_on); | |
d29389de DB |
111 | } |
112 | ||
113 | static inline void setmosi(const struct spi_device *spi, int is_on) | |
114 | { | |
9b00bc7b LW |
115 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); |
116 | ||
117 | gpiod_set_value_cansleep(spi_gpio->mosi, is_on); | |
d29389de DB |
118 | } |
119 | ||
120 | static inline int getmiso(const struct spi_device *spi) | |
121 | { | |
9b00bc7b | 122 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); |
d29389de | 123 | |
4b859db2 LB |
124 | if (spi->mode & SPI_3WIRE) |
125 | return !!gpiod_get_value_cansleep(spi_gpio->mosi); | |
126 | else | |
127 | return !!gpiod_get_value_cansleep(spi_gpio->miso); | |
9b00bc7b | 128 | } |
d29389de DB |
129 | |
130 | /* | |
131 | * NOTE: this clocks "as fast as we can". It "should" be a function of the | |
132 | * requested device clock. Software overhead means we usually have trouble | |
133 | * reaching even one Mbit/sec (except when we can inline bitops), so for now | |
134 | * we'll just assume we never need additional per-bit slowdowns. | |
135 | */ | |
136 | #define spidelay(nsecs) do {} while (0) | |
137 | ||
ca632f55 | 138 | #include "spi-bitbang-txrx.h" |
d29389de DB |
139 | |
140 | /* | |
141 | * These functions can leverage inline expansion of GPIO calls to shrink | |
142 | * costs for a txrx bit, often by factors of around ten (by instruction | |
143 | * count). That is particularly visible for larger word sizes, but helps | |
144 | * even with default 8-bit words. | |
145 | * | |
146 | * REVISIT overheads calling these functions for each word also have | |
147 | * significant performance costs. Having txrx_bufs() calls that inline | |
148 | * the txrx_word() logic would help performance, e.g. on larger blocks | |
149 | * used with flash storage or MMC/SD. There should also be ways to make | |
150 | * GCC be less stupid about reloading registers inside the I/O loops, | |
151 | * even without inlined GPIO calls; __attribute__((hot)) on GCC 4.3? | |
152 | */ | |
153 | ||
154 | static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi, | |
304d3436 | 155 | unsigned nsecs, u32 word, u8 bits, unsigned flags) |
d29389de | 156 | { |
304d3436 | 157 | return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); |
d29389de DB |
158 | } |
159 | ||
160 | static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi, | |
304d3436 | 161 | unsigned nsecs, u32 word, u8 bits, unsigned flags) |
d29389de | 162 | { |
304d3436 | 163 | return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); |
d29389de DB |
164 | } |
165 | ||
166 | static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi, | |
304d3436 | 167 | unsigned nsecs, u32 word, u8 bits, unsigned flags) |
d29389de | 168 | { |
304d3436 | 169 | return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); |
d29389de DB |
170 | } |
171 | ||
172 | static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi, | |
304d3436 | 173 | unsigned nsecs, u32 word, u8 bits, unsigned flags) |
d29389de | 174 | { |
304d3436 | 175 | return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); |
d29389de DB |
176 | } |
177 | ||
3c8e1a84 MS |
178 | /* |
179 | * These functions do not call setmosi or getmiso if respective flag | |
180 | * (SPI_MASTER_NO_RX or SPI_MASTER_NO_TX) is set, so they are safe to | |
181 | * call when such pin is not present or defined in the controller. | |
182 | * A separate set of callbacks is defined to get highest possible | |
183 | * speed in the generic case (when both MISO and MOSI lines are | |
184 | * available), as optimiser will remove the checks when argument is | |
185 | * constant. | |
186 | */ | |
187 | ||
188 | static u32 spi_gpio_spec_txrx_word_mode0(struct spi_device *spi, | |
304d3436 | 189 | unsigned nsecs, u32 word, u8 bits, unsigned flags) |
3c8e1a84 | 190 | { |
304d3436 | 191 | flags = spi->master->flags; |
3c8e1a84 MS |
192 | return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); |
193 | } | |
194 | ||
195 | static u32 spi_gpio_spec_txrx_word_mode1(struct spi_device *spi, | |
304d3436 | 196 | unsigned nsecs, u32 word, u8 bits, unsigned flags) |
3c8e1a84 | 197 | { |
304d3436 | 198 | flags = spi->master->flags; |
3c8e1a84 MS |
199 | return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); |
200 | } | |
201 | ||
202 | static u32 spi_gpio_spec_txrx_word_mode2(struct spi_device *spi, | |
304d3436 | 203 | unsigned nsecs, u32 word, u8 bits, unsigned flags) |
3c8e1a84 | 204 | { |
304d3436 | 205 | flags = spi->master->flags; |
3c8e1a84 MS |
206 | return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); |
207 | } | |
208 | ||
209 | static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi, | |
304d3436 | 210 | unsigned nsecs, u32 word, u8 bits, unsigned flags) |
3c8e1a84 | 211 | { |
304d3436 | 212 | flags = spi->master->flags; |
3c8e1a84 MS |
213 | return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); |
214 | } | |
215 | ||
d29389de DB |
216 | /*----------------------------------------------------------------------*/ |
217 | ||
218 | static void spi_gpio_chipselect(struct spi_device *spi, int is_active) | |
219 | { | |
161c2dd3 | 220 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); |
d29389de | 221 | |
9b00bc7b | 222 | /* set initial clock line level */ |
d29389de | 223 | if (is_active) |
9b00bc7b LW |
224 | gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL); |
225 | ||
226 | /* Drive chip select line, if we have one */ | |
227 | if (spi_gpio->has_cs) { | |
228 | struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select]; | |
d29389de | 229 | |
9b00bc7b LW |
230 | /* SPI chip selects are normally active-low */ |
231 | gpiod_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); | |
bfb9bcdb | 232 | } |
d29389de DB |
233 | } |
234 | ||
235 | static int spi_gpio_setup(struct spi_device *spi) | |
236 | { | |
9b00bc7b | 237 | struct gpio_desc *cs; |
161c2dd3 DM |
238 | int status = 0; |
239 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); | |
38ab18ca | 240 | |
9b00bc7b LW |
241 | /* |
242 | * The CS GPIOs have already been | |
243 | * initialized from the descriptor lookup. | |
244 | */ | |
245 | cs = spi_gpio->cs_gpios[spi->chip_select]; | |
246 | if (!spi->controller_state && cs) | |
247 | status = gpiod_direction_output(cs, | |
248 | !(spi->mode & SPI_CS_HIGH)); | |
249 | ||
250 | if (!status) | |
6b8cc330 | 251 | status = spi_bitbang_setup(spi); |
161c2dd3 | 252 | |
d29389de DB |
253 | return status; |
254 | } | |
255 | ||
4b859db2 LB |
256 | static int spi_gpio_set_direction(struct spi_device *spi, bool output) |
257 | { | |
258 | struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi); | |
5132b3d2 | 259 | int ret; |
4b859db2 LB |
260 | |
261 | if (output) | |
262 | return gpiod_direction_output(spi_gpio->mosi, 1); | |
5132b3d2 LW |
263 | |
264 | ret = gpiod_direction_input(spi_gpio->mosi); | |
265 | if (ret) | |
266 | return ret; | |
267 | /* | |
268 | * Send a turnaround high impedance cycle when switching | |
269 | * from output to input. Theoretically there should be | |
270 | * a clock delay here, but as has been noted above, the | |
271 | * nsec delay function for bit-banged GPIO is simply | |
272 | * {} because bit-banging just doesn't get fast enough | |
273 | * anyway. | |
274 | */ | |
275 | if (spi->mode & SPI_3WIRE_HIZ) { | |
276 | gpiod_set_value_cansleep(spi_gpio->sck, | |
277 | !(spi->mode & SPI_CPOL)); | |
278 | gpiod_set_value_cansleep(spi_gpio->sck, | |
279 | !!(spi->mode & SPI_CPOL)); | |
280 | } | |
281 | return 0; | |
4b859db2 LB |
282 | } |
283 | ||
d29389de DB |
284 | static void spi_gpio_cleanup(struct spi_device *spi) |
285 | { | |
d29389de DB |
286 | spi_bitbang_cleanup(spi); |
287 | } | |
288 | ||
9b00bc7b LW |
289 | /* |
290 | * It can be convenient to use this driver with pins that have alternate | |
291 | * functions associated with a "native" SPI controller if a driver for that | |
292 | * controller is not available, or is missing important functionality. | |
293 | * | |
294 | * On platforms which can do so, configure MISO with a weak pullup unless | |
295 | * there's an external pullup on that signal. That saves power by avoiding | |
296 | * floating signals. (A weak pulldown would save power too, but many | |
297 | * drivers expect to see all-ones data as the no slave "response".) | |
298 | */ | |
299 | static int spi_gpio_request(struct device *dev, | |
300 | struct spi_gpio *spi_gpio, | |
301 | unsigned int num_chipselects, | |
302 | u16 *mflags) | |
d29389de | 303 | { |
9b00bc7b | 304 | int i; |
d29389de | 305 | |
9b00bc7b LW |
306 | spi_gpio->mosi = devm_gpiod_get_optional(dev, "mosi", GPIOD_OUT_LOW); |
307 | if (IS_ERR(spi_gpio->mosi)) | |
308 | return PTR_ERR(spi_gpio->mosi); | |
309 | if (!spi_gpio->mosi) | |
3c8e1a84 | 310 | /* HW configuration without MOSI pin */ |
9b00bc7b | 311 | *mflags |= SPI_MASTER_NO_TX; |
d29389de | 312 | |
9b00bc7b LW |
313 | spi_gpio->miso = devm_gpiod_get_optional(dev, "miso", GPIOD_IN); |
314 | if (IS_ERR(spi_gpio->miso)) | |
315 | return PTR_ERR(spi_gpio->miso); | |
abf5feef LW |
316 | /* |
317 | * No setting SPI_MASTER_NO_RX here - if there is only a MOSI | |
318 | * pin connected the host can still do RX by changing the | |
319 | * direction of the line. | |
320 | */ | |
d29389de | 321 | |
9b00bc7b | 322 | spi_gpio->sck = devm_gpiod_get(dev, "sck", GPIOD_OUT_LOW); |
1723c315 LW |
323 | if (IS_ERR(spi_gpio->sck)) |
324 | return PTR_ERR(spi_gpio->sck); | |
d29389de | 325 | |
9b00bc7b LW |
326 | for (i = 0; i < num_chipselects; i++) { |
327 | spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", | |
328 | i, GPIOD_OUT_HIGH); | |
329 | if (IS_ERR(spi_gpio->cs_gpios[i])) | |
330 | return PTR_ERR(spi_gpio->cs_gpios[i]); | |
331 | } | |
d29389de | 332 | |
9b00bc7b | 333 | return 0; |
d29389de DB |
334 | } |
335 | ||
38ab18ca | 336 | #ifdef CONFIG_OF |
d9e15281 | 337 | static const struct of_device_id spi_gpio_dt_ids[] = { |
38ab18ca DM |
338 | { .compatible = "spi-gpio" }, |
339 | {} | |
340 | }; | |
341 | MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids); | |
342 | ||
343 | static int spi_gpio_probe_dt(struct platform_device *pdev) | |
344 | { | |
345 | int ret; | |
346 | u32 tmp; | |
347 | struct spi_gpio_platform_data *pdata; | |
348 | struct device_node *np = pdev->dev.of_node; | |
349 | const struct of_device_id *of_id = | |
350 | of_match_device(spi_gpio_dt_ids, &pdev->dev); | |
351 | ||
352 | if (!of_id) | |
353 | return 0; | |
354 | ||
355 | pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); | |
356 | if (!pdata) | |
357 | return -ENOMEM; | |
358 | ||
38ab18ca DM |
359 | |
360 | ret = of_property_read_u32(np, "num-chipselects", &tmp); | |
361 | if (ret < 0) { | |
362 | dev_err(&pdev->dev, "num-chipselects property not found\n"); | |
363 | goto error_free; | |
364 | } | |
365 | ||
366 | pdata->num_chipselect = tmp; | |
367 | pdev->dev.platform_data = pdata; | |
368 | ||
369 | return 1; | |
370 | ||
371 | error_free: | |
372 | devm_kfree(&pdev->dev, pdata); | |
373 | return ret; | |
374 | } | |
375 | #else | |
ac2cb30b | 376 | static inline int spi_gpio_probe_dt(struct platform_device *pdev) |
38ab18ca DM |
377 | { |
378 | return 0; | |
379 | } | |
380 | #endif | |
381 | ||
fd4a319b | 382 | static int spi_gpio_probe(struct platform_device *pdev) |
d29389de DB |
383 | { |
384 | int status; | |
385 | struct spi_master *master; | |
386 | struct spi_gpio *spi_gpio; | |
387 | struct spi_gpio_platform_data *pdata; | |
3c8e1a84 | 388 | u16 master_flags = 0; |
38ab18ca DM |
389 | bool use_of = 0; |
390 | ||
391 | status = spi_gpio_probe_dt(pdev); | |
392 | if (status < 0) | |
393 | return status; | |
394 | if (status > 0) | |
395 | use_of = 1; | |
d29389de | 396 | |
8074cf06 | 397 | pdata = dev_get_platdata(&pdev->dev); |
d29389de | 398 | #ifdef GENERIC_BITBANG |
d1d81802 | 399 | if (!pdata || (!use_of && !pdata->num_chipselect)) |
d29389de DB |
400 | return -ENODEV; |
401 | #endif | |
402 | ||
9b00bc7b LW |
403 | master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio)); |
404 | if (!master) | |
405 | return -ENOMEM; | |
d29389de | 406 | |
d29389de | 407 | spi_gpio = spi_master_get_devdata(master); |
9b00bc7b | 408 | |
a86854d0 KC |
409 | spi_gpio->cs_gpios = devm_kcalloc(&pdev->dev, |
410 | pdata->num_chipselect, | |
411 | sizeof(*spi_gpio->cs_gpios), | |
9b00bc7b LW |
412 | GFP_KERNEL); |
413 | if (!spi_gpio->cs_gpios) | |
414 | return -ENOMEM; | |
415 | ||
d29389de DB |
416 | platform_set_drvdata(pdev, spi_gpio); |
417 | ||
9b00bc7b LW |
418 | /* Determine if we have chip selects connected */ |
419 | spi_gpio->has_cs = !!pdata->num_chipselect; | |
420 | ||
d29389de DB |
421 | spi_gpio->pdev = pdev; |
422 | if (pdata) | |
423 | spi_gpio->pdata = *pdata; | |
424 | ||
9b00bc7b LW |
425 | status = spi_gpio_request(&pdev->dev, spi_gpio, |
426 | pdata->num_chipselect, &master_flags); | |
427 | if (status) | |
428 | return status; | |
429 | ||
24778be2 | 430 | master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); |
b89fefda RK |
431 | master->mode_bits = SPI_3WIRE | SPI_3WIRE_HIZ | SPI_CPHA | SPI_CPOL | |
432 | SPI_CS_HIGH; | |
3c8e1a84 | 433 | master->flags = master_flags; |
d29389de | 434 | master->bus_num = pdev->id; |
9b00bc7b LW |
435 | /* The master needs to think there is a chipselect even if not connected */ |
436 | master->num_chipselect = spi_gpio->has_cs ? pdata->num_chipselect : 1; | |
d29389de DB |
437 | master->setup = spi_gpio_setup; |
438 | master->cleanup = spi_gpio_cleanup; | |
38ab18ca DM |
439 | #ifdef CONFIG_OF |
440 | master->dev.of_node = pdev->dev.of_node; | |
38ab18ca | 441 | #endif |
d29389de | 442 | |
94c69f76 | 443 | spi_gpio->bitbang.master = master; |
d29389de | 444 | spi_gpio->bitbang.chipselect = spi_gpio_chipselect; |
4b859db2 | 445 | spi_gpio->bitbang.set_line_direction = spi_gpio_set_direction; |
3c8e1a84 | 446 | |
abf5feef | 447 | if ((master_flags & SPI_MASTER_NO_TX) == 0) { |
3c8e1a84 MS |
448 | spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0; |
449 | spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1; | |
450 | spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2; | |
451 | spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3; | |
452 | } else { | |
453 | spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0; | |
454 | spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1; | |
455 | spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2; | |
456 | spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3; | |
457 | } | |
d29389de | 458 | spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer; |
d29389de DB |
459 | |
460 | status = spi_bitbang_start(&spi_gpio->bitbang); | |
9b00bc7b | 461 | if (status) |
d29389de | 462 | spi_master_put(master); |
d29389de DB |
463 | |
464 | return status; | |
465 | } | |
466 | ||
fd4a319b | 467 | static int spi_gpio_remove(struct platform_device *pdev) |
d29389de DB |
468 | { |
469 | struct spi_gpio *spi_gpio; | |
d29389de DB |
470 | |
471 | spi_gpio = platform_get_drvdata(pdev); | |
d29389de DB |
472 | |
473 | /* stop() unregisters child devices too */ | |
d9721ae1 | 474 | spi_bitbang_stop(&spi_gpio->bitbang); |
d29389de | 475 | |
94c69f76 | 476 | spi_master_put(spi_gpio->bitbang.master); |
d29389de | 477 | |
d9721ae1 | 478 | return 0; |
d29389de DB |
479 | } |
480 | ||
481 | MODULE_ALIAS("platform:" DRIVER_NAME); | |
482 | ||
483 | static struct platform_driver spi_gpio_driver = { | |
38ab18ca DM |
484 | .driver = { |
485 | .name = DRIVER_NAME, | |
38ab18ca DM |
486 | .of_match_table = of_match_ptr(spi_gpio_dt_ids), |
487 | }, | |
940ab889 | 488 | .probe = spi_gpio_probe, |
fd4a319b | 489 | .remove = spi_gpio_remove, |
d29389de | 490 | }; |
940ab889 | 491 | module_platform_driver(spi_gpio_driver); |
d29389de DB |
492 | |
493 | MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO "); | |
494 | MODULE_AUTHOR("David Brownell"); | |
495 | MODULE_LICENSE("GPL"); |