/**************************************************************************** * boards/arm/sam34/sam4e-ek/src/sam_spi.c * * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. The * ASF licenses this file to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance with the * License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include "arm_internal.h" #include "chip.h" #include "sam_gpio.h" #include "sam_spi.h" #include "sam4e-ek.h" #if defined(CONFIG_SAM34_SPI0) /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: sam_spidev_initialize * * Description: * Called to configure SPI chip select GPIO pins for the SAM4E-EK board. * ****************************************************************************/ void weak_function sam_spidev_initialize(void) { #if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_ADS7843E) /* The touchscreen connects using NPCS0 (PA11). */ sam_configgpio(GPIO_TSC_CS); #endif #if defined(CONFIG_MTD_AT25) /* The AT25 Serial FLASH connects using NPCS3 (PA5). */ sam_configgpio(GPIO_FLASH_CS); #endif } /**************************************************************************** * Name: sam_spi0select, sam_spi0status, and sam_spic0mddata * * Description: * These external functions must be provided by board-specific logic. They * include: * * o sam_spi0select is a functions tomanage the board-specific chip selects * o sam_spi0status and sam_spic0mddata: Implementations of the status * and cmddata methods of the SPI interface defined by struct spi_ops_ * (see include/nuttx/spi/spi.h). All other methods including * sam_spibus_initialize()) are provided by common SAM3/4 logic. * * To use this common SPI logic on your board: * * 1. Provide logic in sam_boardinitialize() to configure SPI chip select * pins. * 2. Provide sam_spi0select() and sam_spi0status() functions in your * board specific logic. These functions will perform chip selection and * status operations using GPIOs in the way your board is configured. * 2. If CONFIG_SPI_CMDDATA is defined in the NuttX configuration, provide * sam_spic0mddata() functions in your board-specific logic. This * function will perform cmd/data selection operations using GPIOs in * the way your board is configured. * 3. Add a call to sam_spibus_initialize() in your low level application * initialization logic * 4. The handle returned by sam_spibus_initialize() may then be used to * bind the SPI driver to higher level logic (e.g., calling * mmcsd_spislotinitialize(), for example, will bind the SPI driver to * the SPI MMC/SD driver). * ****************************************************************************/ /**************************************************************************** * Name: sam_spi0select * * Description: * PIO chip select pins may be programmed by the board specific logic in * one of two different ways. First, the pins may be programmed as SPI * peripherals. In that case, the pins are completely controlled by the * SPI driver. This method still needs to be provided, but it may be only * a stub. * * An alternative way to program the PIO chip select pins is as a normal * GPIO output. In that case, the automatic control of the CS pins is * bypassed and this function must provide control of the chip select. * NOTE: In this case, the GPIO output pin does *not* have to be the * same as the NPCS pin normal associated with the chip select number. * * Input Parameters: * devid - Identifies the (logical) device * selected - TRUE:Select the device, FALSE:De-select the device * * Returned Value: * None * ****************************************************************************/ void sam_spi0select(uint32_t devid, bool selected) { switch (devid) { #if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_ADS7843E) /* The touchscreen chip select is implemented as a GPIO OUTPUT that * must be controlled by this function. * This is because the ADS7843E driver must be able to sample the * device BUSY GPIO input between SPI transfers. * However, the AD7843E will tri-state the BUSY input whenever the * chip select is de-asserted. * So the only option is to control the chip select manually and hold * it low throughout the SPI transfer. */ case SPIDEV_TOUCHSCREEN(0): sam_gpiowrite(GPIO_TSC_CS, !selected); break; #endif #if defined(CONFIG_MTD_AT25) /* The AT25 Serial FLASH connects using NPCS3 (PA5). */ case SPIDEV_FLASH(0): sam_gpiowrite(GPIO_FLASH_CS, !selected); break; #endif default: break; } } /**************************************************************************** * Name: sam_spi0status * * Description: * Return status information associated with the SPI device. * * Input Parameters: * devid - Identifies the (logical) device * * Returned Value: * Bit-encoded SPI status (see include/nuttx/spi/spi.h. * ****************************************************************************/ uint8_t sam_spi0status(struct spi_dev_s *dev, uint32_t devid) { return 0; } #endif /* CONFIG_SAM34_SPI0 || CONFIG_SAM34_SPI1 */