194 lines
7.2 KiB
C
194 lines
7.2 KiB
C
/************************************************************************************
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* configs/sam4e-ek/src/sam_spi.c
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*
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* Copyright (C) 2014 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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************************************************************************************/
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/************************************************************************************
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* Included Files
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************************************************************************************/
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#include <nuttx/config.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <debug.h>
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#include <errno.h>
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#include <nuttx/spi/spi.h>
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#include <arch/board/board.h>
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#include "up_arch.h"
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#include "chip.h"
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#include "sam_gpio.h"
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#include "sam_spi.h"
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#include "sam4e-ek.h"
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#if defined(CONFIG_SAM34_SPI0)
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/************************************************************************************
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* Public Functions
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************************************************************************************/
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/************************************************************************************
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* Name: sam_spidev_initialize
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*
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* Description:
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* Called to configure SPI chip select GPIO pins for the SAM4E-EK board.
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*
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************************************************************************************/
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void weak_function sam_spidev_initialize(void)
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{
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#if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_ADS7843E)
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/* The touchscreen connects using NPCS0 (PA11). */
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sam_configgpio(GPIO_TSC_CS);
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#endif
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#if defined(CONFIG_MTD_AT25)
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/* The AT25 Serial FLASH connects using NPCS3 (PA5). */
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sam_configgpio(GPIO_FLASH_CS);
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#endif
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}
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/****************************************************************************
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* Name: sam_spi0select, sam_spi0status, and sam_spic0mddata
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*
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* Description:
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* These external functions must be provided by board-specific logic. They
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* include:
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*
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* o sam_spi0select is a functions tomanage the board-specific chip selects
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* o sam_spi0status and sam_spic0mddata: Implementations of the status
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* and cmddata methods of the SPI interface defined by struct spi_ops_
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* (see include/nuttx/spi/spi.h). All other methods including
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* sam_spibus_initialize()) are provided by common SAM3/4 logic.
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*
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* To use this common SPI logic on your board:
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*
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* 1. Provide logic in sam_boardinitialize() to configure SPI chip select
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* pins.
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* 2. Provide sam_spi0select() and sam_spi0status() functions in your board-
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* specific logic. These functions will perform chip selection and
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* status operations using GPIOs in the way your board is configured.
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* 2. If CONFIG_SPI_CMDDATA is defined in the NuttX configuration, provide
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* sam_spic0mddata() functions in your board-specific logic. This
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* function will perform cmd/data selection operations using GPIOs in
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* the way your board is configured.
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* 3. Add a call to sam_spibus_initialize() in your low level application
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* initialization logic
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* 4. The handle returned by sam_spibus_initialize() may then be used to bind the
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* SPI driver to higher level logic (e.g., calling
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* mmcsd_spislotinitialize(), for example, will bind the SPI driver to
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* the SPI MMC/SD driver).
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*
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****************************************************************************/
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/****************************************************************************
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* Name: sam_spi0select
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*
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* Description:
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* PIO chip select pins may be programmed by the board specific logic in
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* one of two different ways. First, the pins may be programmed as SPI
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* peripherals. In that case, the pins are completely controlled by the
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* SPI driver. This method still needs to be provided, but it may be only
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* a stub.
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*
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* An alternative way to program the PIO chip select pins is as a normal
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* GPIO output. In that case, the automatic control of the CS pins is
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* bypassed and this function must provide control of the chip select.
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* NOTE: In this case, the GPIO output pin does *not* have to be the
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* same as the NPCS pin normal associated with the chip select number.
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*
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* Input Parameters:
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* devid - Identifies the (logical) device
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* selected - TRUE:Select the device, FALSE:De-select the device
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*
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* Returned Value:
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* None
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*
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****************************************************************************/
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void sam_spi0select(uint32_t devid, bool selected)
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{
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switch (devid)
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{
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#if defined(CONFIG_INPUT) && defined(CONFIG_INPUT_ADS7843E)
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/* The touchscreen chip select is implemented as a GPIO OUTPUT that must
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* be controlled by this function. This is because the ADS7843E driver
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* must be able to sample the device BUSY GPIO input between SPI transfers.
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* However, the AD7843E will tri-state the BUSY input whenever the chip
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* select is de-asserted. So the only option is to control the chip select
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* manually and hold it low throughout the SPI transfer.
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*/
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case SPIDEV_TOUCHSCREEN(0):
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sam_gpiowrite(GPIO_TSC_CS, !selected);
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break;
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#endif
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#if defined(CONFIG_MTD_AT25)
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/* The AT25 Serial FLASH connects using NPCS3 (PA5). */
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case SPIDEV_FLASH(0):
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sam_gpiowrite(GPIO_FLASH_CS, !selected);
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break;
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#endif
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default:
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break;
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}
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}
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/****************************************************************************
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* Name: sam_spi0status
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*
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* Description:
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* Return status information associated with the SPI device.
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*
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* Input Parameters:
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* devid - Identifies the (logical) device
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*
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* Returned Value:
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* Bit-encoded SPI status (see include/nuttx/spi/spi.h.
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*
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****************************************************************************/
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uint8_t sam_spi0status(FAR struct spi_dev_s *dev, uint32_t devid)
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{
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return 0;
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}
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#endif /* CONFIG_SAM34_SPI0 || CONFIG_SAM34_SPI1 */
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