Cirrus EP93xx SPI controller driver HOWTO ========================================= ep93xx_spi driver brings SPI master support for EP93xx SPI controller. Chip selects are implemented with GPIO lines. NOTE: If possible, don't use SFRMOUT (SFRM1) signal as a chip select. It will not work correctly (it cannot be controlled by software). Use GPIO lines instead. Sample configuration ==================== Typically driver configuration is done in platform board files (the files under arch/arm/mach-ep93xx/*.c). In this example we configure MMC over SPI through this driver on TS-7260 board. You can adapt the code to suit your needs. This example uses EGPIO9 as SD/MMC card chip select (this is wired in DIO1 header on the board). You need to select CONFIG_MMC_SPI to use mmc_spi driver. arch/arm/mach-ep93xx/ts72xx.c: ... #include #include #include /* this is our GPIO line used for chip select */ #define MMC_CHIP_SELECT_GPIO EP93XX_GPIO_LINE_EGPIO9 static int ts72xx_mmc_spi_setup(struct spi_device *spi) { int err; err = gpio_request(MMC_CHIP_SELECT_GPIO, spi->modalias); if (err) return err; gpio_direction_output(MMC_CHIP_SELECT_GPIO, 1); return 0; } static void ts72xx_mmc_spi_cleanup(struct spi_device *spi) { gpio_set_value(MMC_CHIP_SELECT_GPIO, 1); gpio_direction_input(MMC_CHIP_SELECT_GPIO); gpio_free(MMC_CHIP_SELECT_GPIO); } static void ts72xx_mmc_spi_cs_control(struct spi_device *spi, int value) { gpio_set_value(MMC_CHIP_SELECT_GPIO, value); } static struct ep93xx_spi_chip_ops ts72xx_mmc_spi_ops = { .setup = ts72xx_mmc_spi_setup, .cleanup = ts72xx_mmc_spi_cleanup, .cs_control = ts72xx_mmc_spi_cs_control, }; static struct spi_board_info ts72xx_spi_devices[] __initdata = { { .modalias = "mmc_spi", .controller_data = &ts72xx_mmc_spi_ops, /* * We use 10 MHz even though the maximum is 7.4 MHz. The driver * will limit it automatically to max. frequency. */ .max_speed_hz = 10 * 1000 * 1000, .bus_num = 0, .chip_select = 0, .mode = SPI_MODE_0, }, }; static struct ep93xx_spi_info ts72xx_spi_info = { .num_chipselect = ARRAY_SIZE(ts72xx_spi_devices), }; static void __init ts72xx_init_machine(void) { ... ep93xx_register_spi(&ts72xx_spi_info, ts72xx_spi_devices, ARRAY_SIZE(ts72xx_spi_devices)); } Thanks to ========= Martin Guy, H. Hartley Sweeten and others who helped me during development of the driver. Simplemachines.it donated me a Sim.One board which I used testing the driver on EP9307.