Lines Matching +full:spi +full:- +full:gpio
2 * SPI master driver using generic bitbanged GPIO
24 #include <linux/gpio.h>
26 #include <linux/spi/spi.h>
27 #include <linux/spi/spi_bitbang.h>
28 #include <linux/spi/spi_gpio.h>
32 * This bitbanging SPI master driver should help make systems usable
33 * when a native hardware SPI engine is not available, perhaps because
37 * platform_device->driver_data ... points to spi_gpio
39 * spi->controller_state ... reserved for bitbang framework code
40 * spi->controller_data ... holds chipselect GPIO
42 * spi->master->dev.driver_data ... points to spi_gpio->bitbang
51 /*----------------------------------------------------------------------*/
54 * Because the overhead of going through four GPIO procedure calls
58 * - The slow generic way: set up platform_data to hold the GPIO
62 * - The quicker inlined way: only helps with platform GPIO code
73 * #include "spi-gpio.c"
82 #define SPI_MISO_GPIO ((pdata)->miso)
83 #define SPI_MOSI_GPIO ((pdata)->mosi)
84 #define SPI_SCK_GPIO ((pdata)->sck)
86 #define SPI_N_CHIPSEL ((pdata)->num_chipselect)
90 /*----------------------------------------------------------------------*/
93 spi_to_pdata(const struct spi_device *spi) in spi_to_pdata() argument
98 bang = spi_master_get_devdata(spi->master); in spi_to_pdata()
100 return &spi_gpio->pdata; in spi_to_pdata()
103 /* this is #defined to avoid unused-variable warnings when inlining */
104 #define pdata spi_to_pdata(spi)
106 static inline void setsck(const struct spi_device *spi, int is_on) in setsck() argument
111 static inline void setmosi(const struct spi_device *spi, int is_on) in setmosi() argument
116 static inline int getmiso(const struct spi_device *spi) in getmiso() argument
127 * we'll just assume we never need additional per-bit slowdowns.
131 #include "spi-bitbang-txrx.h"
134 * These functions can leverage inline expansion of GPIO calls to shrink
137 * even with default 8-bit words.
144 * even without inlined GPIO calls; __attribute__((hot)) on GCC 4.3?
147 static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi, in spi_gpio_txrx_word_mode0() argument
150 return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits); in spi_gpio_txrx_word_mode0()
153 static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi, in spi_gpio_txrx_word_mode1() argument
156 return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits); in spi_gpio_txrx_word_mode1()
159 static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi, in spi_gpio_txrx_word_mode2() argument
162 return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits); in spi_gpio_txrx_word_mode2()
165 static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi, in spi_gpio_txrx_word_mode3() argument
168 return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits); in spi_gpio_txrx_word_mode3()
181 static u32 spi_gpio_spec_txrx_word_mode0(struct spi_device *spi, in spi_gpio_spec_txrx_word_mode0() argument
184 unsigned flags = spi->master->flags; in spi_gpio_spec_txrx_word_mode0()
185 return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits); in spi_gpio_spec_txrx_word_mode0()
188 static u32 spi_gpio_spec_txrx_word_mode1(struct spi_device *spi, in spi_gpio_spec_txrx_word_mode1() argument
191 unsigned flags = spi->master->flags; in spi_gpio_spec_txrx_word_mode1()
192 return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits); in spi_gpio_spec_txrx_word_mode1()
195 static u32 spi_gpio_spec_txrx_word_mode2(struct spi_device *spi, in spi_gpio_spec_txrx_word_mode2() argument
198 unsigned flags = spi->master->flags; in spi_gpio_spec_txrx_word_mode2()
199 return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits); in spi_gpio_spec_txrx_word_mode2()
202 static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi, in spi_gpio_spec_txrx_word_mode3() argument
205 unsigned flags = spi->master->flags; in spi_gpio_spec_txrx_word_mode3()
206 return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits); in spi_gpio_spec_txrx_word_mode3()
209 /*----------------------------------------------------------------------*/
211 static void spi_gpio_chipselect(struct spi_device *spi, int is_active) in spi_gpio_chipselect() argument
213 unsigned long cs = (unsigned long) spi->controller_data; in spi_gpio_chipselect()
217 setsck(spi, spi->mode & SPI_CPOL); in spi_gpio_chipselect()
220 /* SPI is normally active-low */ in spi_gpio_chipselect()
221 gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); in spi_gpio_chipselect()
225 static int spi_gpio_setup(struct spi_device *spi) in spi_gpio_setup() argument
227 unsigned long cs = (unsigned long) spi->controller_data; in spi_gpio_setup()
230 if (spi->bits_per_word > 32) in spi_gpio_setup()
231 return -EINVAL; in spi_gpio_setup()
233 if (!spi->controller_state) { in spi_gpio_setup()
235 status = gpio_request(cs, dev_name(&spi->dev)); in spi_gpio_setup()
238 status = gpio_direction_output(cs, spi->mode & SPI_CS_HIGH); in spi_gpio_setup()
242 status = spi_bitbang_setup(spi); in spi_gpio_setup()
244 if (!spi->controller_state && cs != SPI_GPIO_NO_CHIPSELECT) in spi_gpio_setup()
250 static void spi_gpio_cleanup(struct spi_device *spi) in spi_gpio_cleanup() argument
252 unsigned long cs = (unsigned long) spi->controller_data; in spi_gpio_cleanup()
256 spi_bitbang_cleanup(spi); in spi_gpio_cleanup()
323 pdata = pdev->dev.platform_data; in spi_gpio_probe()
325 if (!pdata || !pdata->num_chipselect) in spi_gpio_probe()
326 return -ENODEV; in spi_gpio_probe()
329 status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags); in spi_gpio_probe()
333 master = spi_alloc_master(&pdev->dev, sizeof *spi_gpio); in spi_gpio_probe()
335 status = -ENOMEM; in spi_gpio_probe()
341 spi_gpio->pdev = pdev; in spi_gpio_probe()
343 spi_gpio->pdata = *pdata; in spi_gpio_probe()
345 master->flags = master_flags; in spi_gpio_probe()
346 master->bus_num = pdev->id; in spi_gpio_probe()
347 master->num_chipselect = SPI_N_CHIPSEL; in spi_gpio_probe()
348 master->setup = spi_gpio_setup; in spi_gpio_probe()
349 master->cleanup = spi_gpio_cleanup; in spi_gpio_probe()
351 spi_gpio->bitbang.master = spi_master_get(master); in spi_gpio_probe()
352 spi_gpio->bitbang.chipselect = spi_gpio_chipselect; in spi_gpio_probe()
355 spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0; in spi_gpio_probe()
356 spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1; in spi_gpio_probe()
357 spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2; in spi_gpio_probe()
358 spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3; in spi_gpio_probe()
360 spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0; in spi_gpio_probe()
361 spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1; in spi_gpio_probe()
362 spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2; in spi_gpio_probe()
363 spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3; in spi_gpio_probe()
365 spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer; in spi_gpio_probe()
366 spi_gpio->bitbang.flags = SPI_CS_HIGH; in spi_gpio_probe()
368 status = spi_bitbang_start(&spi_gpio->bitbang); in spi_gpio_probe()
370 spi_master_put(spi_gpio->bitbang.master); in spi_gpio_probe()
390 pdata = pdev->dev.platform_data; in spi_gpio_remove()
393 status = spi_bitbang_stop(&spi_gpio->bitbang); in spi_gpio_remove()
394 spi_master_put(spi_gpio->bitbang.master); in spi_gpio_remove()
417 MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO ");