207 lines
7.2 KiB
C
207 lines
7.2 KiB
C
/****************************************************************************
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* boards/arm/sam34/flipnclick-sam3x/src/sam_spi0.c
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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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 <assert.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 "arm_internal.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 "flipnclick-sam3x.h"
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#ifdef 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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#ifdef HAVE_SSD1306
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/* Configure the SSD1306 chip select and command/data GPIOs */
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sam_configgpio(GPIO_SSD1306_CS);
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sam_configgpio(GPIO_SSD1306_DC);
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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.
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* They 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
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* board- specific logic. These functions will perform chip selection
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* and status operations using GPIOs in the way your board is
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* 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
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* bind the 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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spiinfo("devid: %08x CS: %s\n",
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(unsigned int)devid, selected ? "assert" : "de-assert");
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#ifdef HAVE_SSD1306
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if (devid == SPIDEV_DISPLAY(0))
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{
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/* Low: the display is selected
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* High: the display is deselected
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*/
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sam_gpiowrite(GPIO_SSD1306_CS, !selected);
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}
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#endif
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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(struct spi_dev_s *dev, uint32_t devid)
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{
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spiinfo("Returning nothing\n");
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return 0;
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}
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/****************************************************************************
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* Name: sam_spi0cmddata
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*
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* Description:
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* Some SPI devices require an additional control to determine if the SPI
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* data being sent is a command or is data. If CONFIG_SPI_CMDDATA then
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* this function will be called to different be command and data transfers.
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*
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* This is often needed, for example, by LCD drivers. Some LCD hardware
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* may be configured to use 9-bit data transfers with the 9th bit
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* indicating command or data. That same hardware may be configurable,
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* instead, to use 8-bit data but to require an additional, board-
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* specific PIO control to distinguish command and data. This function
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* would be needed in that latter case.
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*
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* Input Parameters:
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* dev - SPI device info
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* devid - Identifies the (logical) device
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*
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* Returned Value:
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* Zero on success; a negated errno on failure.
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*
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****************************************************************************/
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#ifdef CONFIG_SPI_CMDDATA
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int sam_spi0cmddata(struct spi_dev_s *dev, uint32_t devid, bool cmd)
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{
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spiinfo("devid: %08x %s\n", (unsigned int)devid, cmd ? "cmd" : "data");
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#ifdef HAVE_SSD1306
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if (devid == SPIDEV_DISPLAY(0))
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{
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/* High: the inputs are treated as display data.
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* Low: the inputs are transferred to the command registers.
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*/
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sam_gpiowrite(GPIO_SSD1306_DC, !cmd);
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}
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#endif
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return 0;
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}
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#endif
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#endif /* CONFIG_SAM34_SPI0 */
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