1 // SPDX-License-Identifier: GPL-2.0-or-later
26  * platform_device->driver_data ... points to spi_gpio
28  * spi->controller_state ... reserved for bitbang framework code
30  * spi->master->dev.driver_data ... points to spi_gpio->bitbang
35 	struct gpio_desc		*sck;  member
41 /*----------------------------------------------------------------------*/
48  *   - The slow generic way:  set up platform_data to hold the GPIO
49  *     numbers used for MISO/MOSI/SCK, and issue procedure calls for
52  *   - The quicker inlined way:  only helps with platform GPIO code
53  *     that inlines operations for constant GPIOs.  This can give
63  *		#include "spi-gpio.c"
73 /*----------------------------------------------------------------------*/
81 	bang = spi_master_get_devdata(spi->master);  in spi_to_spi_gpio()
91 	gpiod_set_value_cansleep(spi_gpio->sck, is_on);  in setsck()
98 	gpiod_set_value_cansleep(spi_gpio->mosi, is_on);  in setmosi()
105 	if (spi->mode & SPI_3WIRE)  in getmiso()
106 		return !!gpiod_get_value_cansleep(spi_gpio->mosi);  in getmiso()
108 		return !!gpiod_get_value_cansleep(spi_gpio->miso);  in getmiso()
115  * we'll just assume we never need additional per-bit slowdowns.
119 #include "spi-bitbang-txrx.h"
125  * even with default 8-bit words.
138 	if (unlikely(spi->mode & SPI_LSB_FIRST))  in spi_gpio_txrx_word_mode0()
147 	if (unlikely(spi->mode & SPI_LSB_FIRST))  in spi_gpio_txrx_word_mode1()
156 	if (unlikely(spi->mode & SPI_LSB_FIRST))  in spi_gpio_txrx_word_mode2()
165 	if (unlikely(spi->mode & SPI_LSB_FIRST))  in spi_gpio_txrx_word_mode3()
184 	flags = spi->master->flags;  in spi_gpio_spec_txrx_word_mode0()
185 	if (unlikely(spi->mode & SPI_LSB_FIRST))  in spi_gpio_spec_txrx_word_mode0()
194 	flags = spi->master->flags;  in spi_gpio_spec_txrx_word_mode1()
195 	if (unlikely(spi->mode & SPI_LSB_FIRST))  in spi_gpio_spec_txrx_word_mode1()
204 	flags = spi->master->flags;  in spi_gpio_spec_txrx_word_mode2()
205 	if (unlikely(spi->mode & SPI_LSB_FIRST))  in spi_gpio_spec_txrx_word_mode2()
214 	flags = spi->master->flags;  in spi_gpio_spec_txrx_word_mode3()
215 	if (unlikely(spi->mode & SPI_LSB_FIRST))  in spi_gpio_spec_txrx_word_mode3()
221 /*----------------------------------------------------------------------*/
229 		gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL);  in spi_gpio_chipselect()
232 	if (spi_gpio->cs_gpios) {  in spi_gpio_chipselect()
233 		struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select];  in spi_gpio_chipselect()
235 		/* SPI chip selects are normally active-low */  in spi_gpio_chipselect()
236 		gpiod_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);  in spi_gpio_chipselect()
247 	 * The CS GPIOs have already been  in spi_gpio_setup()
250 	if (spi_gpio->cs_gpios) {  in spi_gpio_setup()
251 		cs = spi_gpio->cs_gpios[spi->chip_select];  in spi_gpio_setup()
252 		if (!spi->controller_state && cs)  in spi_gpio_setup()
254 						  !(spi->mode & SPI_CS_HIGH));  in spi_gpio_setup()
269 		return gpiod_direction_output(spi_gpio->mosi, 1);  in spi_gpio_set_direction()
271 	ret = gpiod_direction_input(spi_gpio->mosi);  in spi_gpio_set_direction()
278 	 * nsec delay function for bit-banged GPIO is simply  in spi_gpio_set_direction()
279 	 * {} because bit-banging just doesn't get fast enough  in spi_gpio_set_direction()
282 	if (spi->mode & SPI_3WIRE_HIZ) {  in spi_gpio_set_direction()
283 		gpiod_set_value_cansleep(spi_gpio->sck,  in spi_gpio_set_direction()
284 					 !(spi->mode & SPI_CPOL));  in spi_gpio_set_direction()
285 		gpiod_set_value_cansleep(spi_gpio->sck,  in spi_gpio_set_direction()
286 					 !!(spi->mode & SPI_CPOL));  in spi_gpio_set_direction()
304  * drivers expect to see all-ones data as the no slave "response".)
308 	spi_gpio->mosi = devm_gpiod_get_optional(dev, "mosi", GPIOD_OUT_LOW);  in spi_gpio_request()
309 	if (IS_ERR(spi_gpio->mosi))  in spi_gpio_request()
310 		return PTR_ERR(spi_gpio->mosi);  in spi_gpio_request()
312 	spi_gpio->miso = devm_gpiod_get_optional(dev, "miso", GPIOD_IN);  in spi_gpio_request()
313 	if (IS_ERR(spi_gpio->miso))  in spi_gpio_request()
314 		return PTR_ERR(spi_gpio->miso);  in spi_gpio_request()
316 	spi_gpio->sck = devm_gpiod_get(dev, "sck", GPIOD_OUT_LOW);  in spi_gpio_request()
317 	return PTR_ERR_OR_ZERO(spi_gpio->sck);  in spi_gpio_request()
322 	{ .compatible = "spi-gpio" },
330 	master->dev.of_node = pdev->dev.of_node;  in spi_gpio_probe_dt()
331 	master->use_gpio_descriptors = true;  in spi_gpio_probe_dt()
346 	struct device *dev = &pdev->dev;  in spi_gpio_probe_pdata()
352 	if (!pdata || !pdata->num_chipselect)  in spi_gpio_probe_pdata()
353 		return -ENODEV;  in spi_gpio_probe_pdata()
359 	master->num_chipselect = pdata->num_chipselect ?: 1;  in spi_gpio_probe_pdata()
361 	spi_gpio->cs_gpios = devm_kcalloc(dev, master->num_chipselect,  in spi_gpio_probe_pdata()
362 					  sizeof(*spi_gpio->cs_gpios),  in spi_gpio_probe_pdata()
364 	if (!spi_gpio->cs_gpios)  in spi_gpio_probe_pdata()
365 		return -ENOMEM;  in spi_gpio_probe_pdata()
367 	for (i = 0; i < master->num_chipselect; i++) {  in spi_gpio_probe_pdata()
368 		spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", i,  in spi_gpio_probe_pdata()
370 		if (IS_ERR(spi_gpio->cs_gpios[i]))  in spi_gpio_probe_pdata()
371 			return PTR_ERR(spi_gpio->cs_gpios[i]);  in spi_gpio_probe_pdata()
382 	struct device			*dev = &pdev->dev;  in spi_gpio_probe()
387 		return -ENOMEM;  in spi_gpio_probe()
389 	if (pdev->dev.of_node)  in spi_gpio_probe()
403 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);  in spi_gpio_probe()
404 	master->mode_bits = SPI_3WIRE | SPI_3WIRE_HIZ | SPI_CPHA | SPI_CPOL |  in spi_gpio_probe()
406 	if (!spi_gpio->mosi) {  in spi_gpio_probe()
409 		 * No setting SPI_MASTER_NO_RX here - if there is only  in spi_gpio_probe()
413 		master->flags = SPI_MASTER_NO_TX;  in spi_gpio_probe()
416 	master->bus_num = pdev->id;  in spi_gpio_probe()
417 	master->setup = spi_gpio_setup;  in spi_gpio_probe()
418 	master->cleanup = spi_gpio_cleanup;  in spi_gpio_probe()
420 	bb = &spi_gpio->bitbang;  in spi_gpio_probe()
421 	bb->master = master;  in spi_gpio_probe()
427 	master->flags |= SPI_MASTER_GPIO_SS;  in spi_gpio_probe()
428 	bb->chipselect = spi_gpio_chipselect;  in spi_gpio_probe()
429 	bb->set_line_direction = spi_gpio_set_direction;  in spi_gpio_probe()
431 	if (master->flags & SPI_MASTER_NO_TX) {  in spi_gpio_probe()
432 		bb->txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0;  in spi_gpio_probe()
433 		bb->txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1;  in spi_gpio_probe()
434 		bb->txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2;  in spi_gpio_probe()
435 		bb->txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3;  in spi_gpio_probe()
437 		bb->txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0;  in spi_gpio_probe()
438 		bb->txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1;  in spi_gpio_probe()
439 		bb->txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;  in spi_gpio_probe()
440 		bb->txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;  in spi_gpio_probe()
442 	bb->setup_transfer = spi_bitbang_setup_transfer;  in spi_gpio_probe()
444 	status = spi_bitbang_init(&spi_gpio->bitbang);  in spi_gpio_probe()
448 	return devm_spi_register_master(&pdev->dev, master);  in spi_gpio_probe()