/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __LINUX_SPI_GPIO_H #define __LINUX_SPI_GPIO_H /* * For each bitbanged SPI bus, set up a platform_device node with: * - name "spi_gpio" * - id the same as the SPI bus number it implements * - dev.platform data pointing to a struct spi_gpio_platform_data * * Or, see the driver code for information about speedups that are * possible on platforms that support inlined access for GPIOs (no * spi_gpio_platform_data is used). * * Use spi_board_info with these busses in the usual way, being sure * that the controller_data being the GPIO used for each device's * chipselect: * * static struct spi_board_info ... [] = { * ... * // this slave uses GPIO 42 for its chipselect * .controller_data = (void *) 42, * ... * // this one uses GPIO 86 for its chipselect * .controller_data = (void *) 86, * ... * }; * * If chipselect is not used (there's only one device on the bus), assign * SPI_GPIO_NO_CHIPSELECT to the controller_data: * .controller_data = (void *) SPI_GPIO_NO_CHIPSELECT; * * If the MISO or MOSI pin is not available then it should be set to * SPI_GPIO_NO_MISO or SPI_GPIO_NO_MOSI. * * If the bitbanged bus is later switched to a "native" controller, * that platform_device and controller_data should be removed. */ #define SPI_GPIO_NO_CHIPSELECT ((unsigned long)-1l) #define SPI_GPIO_NO_MISO ((unsigned long)-1l) #define SPI_GPIO_NO_MOSI ((unsigned long)-1l) /** * struct spi_gpio_platform_data - parameter for bitbanged SPI master * @sck: number of the GPIO used for clock output * @mosi: number of the GPIO used for Master Output, Slave In (MOSI) data * @miso: number of the GPIO used for Master Input, Slave Output (MISO) data * @num_chipselect: how many slaves to allow * * All GPIO signals used with the SPI bus managed through this driver * (chipselects, MOSI, MISO, SCK) must be configured as GPIOs, instead * of some alternate function. * * It can be convenient to use this driver with pins that have alternate * functions associated with a "native" SPI controller if a driver for that * controller is not available, or is missing important functionality. * * On platforms which can do so, configure MISO with a weak pullup unless * there's an external pullup on that signal. That saves power by avoiding * floating signals. (A weak pulldown would save power too, but many * drivers expect to see all-ones data as the no slave "response".) */ struct spi_gpio_platform_data { unsigned sck; unsigned long mosi; unsigned long miso; u16 num_chipselect; }; #endif /* __LINUX_SPI_GPIO_H */
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ad7877.h | File | 835 B | 0644 |
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adi_spi3.h | File | 15.1 KB | 0644 |
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ads7846.h | File | 2.02 KB | 0644 |
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at73c213.h | File | 828 B | 0644 |
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at86rf230.h | File | 724 B | 0644 |
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cc2520.h | File | 620 B | 0644 |
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ds1305.h | File | 1.08 KB | 0644 |
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flash.h | File | 1023 B | 0644 |
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ifx_modem.h | File | 616 B | 0644 |
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l4f00242t03.h | File | 847 B | 0644 |
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libertas_spi.h | File | 907 B | 0644 |
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lms283gf05.h | File | 775 B | 0644 |
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max7301.h | File | 939 B | 0644 |
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mc33880.h | File | 196 B | 0644 |
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mcp23s08.h | File | 685 B | 0644 |
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mmc_spi.h | File | 1.91 KB | 0644 |
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mxs-spi.h | File | 5.24 KB | 0644 |
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pxa2xx_spi.h | File | 1.5 KB | 0644 |
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rspi.h | File | 715 B | 0644 |
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s3c24xx.h | File | 816 B | 0644 |
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sh_hspi.h | File | 572 B | 0644 |
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sh_msiof.h | File | 357 B | 0644 |
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spi-fsl-dspi.h | File | 955 B | 0644 |
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spi.h | File | 50.33 KB | 0644 |
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spi_bitbang.h | File | 1.43 KB | 0644 |
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spi_gpio.h | File | 2.56 KB | 0644 |
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spi_oc_tiny.h | File | 628 B | 0644 |
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tdo24m.h | File | 210 B | 0644 |
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tle62x0.h | File | 660 B | 0644 |
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xilinx_spi.h | File | 627 B | 0644 |
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