==== About ==== Controlling the SPI bus from userspace allows you to communicate with SPI devices without messing with kernel drivers, which can be painful and make you reboot often. ==== Setup ==== See the [[carambola_where_to_start|tutorial]] for building the image, but before launching "make" apply this patch: <code> diff --git a/target/linux/ramips/files/arch/mips/ralink/rt305x/mach-carambola.c b/target/linux/ramips/files/arch/mips/ralink/rt305x/mach-carambola.c index baa23c1..66d1930 100644 --- a/target/linux/ramips/files/arch/mips/ralink/rt305x/mach-carambola.c +++ b/target/linux/ramips/files/arch/mips/ralink/rt305x/mach-carambola.c @@ -21,9 +21,12 @@ #include <asm/sizes.h> #include <linux/i2c.h> #include <linux/i2c-gpio.h> +#include <linux/spi/spi.h> #include "devices.h" +#define CONFIG_MTD_PARTITIONS 1 + #ifdef CONFIG_MTD_PARTITIONS #define CARAMBOLA_UBOOT_SIZE 0x030000 /* 192KB */ @@ -62,12 +65,12 @@ static struct mtd_partition carambola_partitions[] = { }; #endif /* CONFIG_MTD_PARTITIONS */ -static struct physmap_flash_data carambola_flash_data = { -#ifdef CONFIG_MTD_PARTITIONS - .nr_parts = ARRAY_SIZE(carambola_partitions), - .parts = carambola_partitions, -#endif -}; +// static struct physmap_flash_data carambola_flash_data = { +// #ifdef CONFIG_MTD_PARTITIONS +// .nr_parts = ARRAY_SIZE(carambola_partitions), +// .parts = carambola_partitions, +// #endif +// }; static int __init carambola_register_gpiodev(void) @@ -99,6 +102,16 @@ static struct platform_device carambola_i2c_gpio = { }, }; +struct spi_board_info carambola_spi_dev_info[] __initdata = { + { + .modalias = "spidev", + .max_speed_hz = 10000000, + .bus_num = 0, + .chip_select = 0, + .mode = SPI_MODE_0, + }, +}; + static struct platform_device *carambola_devices[] __initdata = { &carambola_i2c_gpio }; @@ -106,10 +119,16 @@ static struct platform_device *carambola_devices[] __initdata = { static void __init carambola_init(void) { rt305x_gpio_init((RT305X_GPIO_MODE_GPIO << RT305X_GPIO_MODE_UART0_SHIFT) | - RT305X_GPIO_MODE_I2C); + RT305X_GPIO_MODE_I2C | RT305X_GPIO_MODE_SPI); carambola_register_gpiodev(); + rt305x_register_spi(carambola_spi_dev_info, + ARRAY_SIZE(carambola_spi_dev_info)); platform_add_devices(carambola_devices, ARRAY_SIZE(carambola_devices)); - rt305x_register_flash(0, &carambola_flash_data); + #ifdef CONFIG_MTD_PARTITIONS + rt305x_flash0_data.nr_parts = ARRAY_SIZE(carambola_partitions); + rt305x_flash0_data.parts = carambola_partitions; + #endif + rt305x_register_flash(0); rt305x_esw_data.vlan_config = RT305X_ESW_VLAN_CONFIG_LLLLW; rt305x_register_ethernet(); </code> After compiling the image, you should find the file /dev/spidev0.0 ==== Enabling the SPI bus controller ==== To "connect" the bus to the actual pins (instead of using them as GPIOs) use the 'io' tool to clear the bit 1 of the memory address 0x10000060 io 0x10000060 0x1d ==== Coding ==== see [[using_spi_from_python|Using SPI from python]]