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Diffstat (limited to 'nuttx/arch/arm/src/sam34/sam_spi.h')
| -rw-r--r-- | nuttx/arch/arm/src/sam34/sam_spi.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/sam34/sam_spi.h b/nuttx/arch/arm/src/sam34/sam_spi.h new file mode 100644 index 000000000..77e6e26f3 --- /dev/null +++ b/nuttx/arch/arm/src/sam34/sam_spi.h @@ -0,0 +1,226 @@ +/************************************************************************************ + * arch/arm/src/sam34/sam_spi.h + * + * Copyright (C) 2009-2011, 2013 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ************************************************************************************/ + +#ifndef __ARCH_ARM_SRC_SAM34_SAM_SPI_H +#define __ARCH_ARM_SRC_SAM34_SAM_SPI_H + +/************************************************************************************ + * Included Files + ************************************************************************************/ + +#include <nuttx/config.h> + +#include <stdint.h> +#include <stdbool.h> + +#include "chip.h" + +/************************************************************************************ + * Definitions + ************************************************************************************/ + +/************************************************************************************ + * Public Types + ************************************************************************************/ + +/************************************************************************************ + * Inline Functions + ************************************************************************************/ + +#ifndef __ASSEMBLY__ + +/************************************************************************************ + * Public Data + ************************************************************************************/ + +#undef EXTERN +#if defined(__cplusplus) +#define EXTERN extern "C" +extern "C" +{ +#else +#define EXTERN extern +#endif + +/************************************************************************************ + * Public Function Prototypes + ************************************************************************************/ + +/**************************************************************************** + * Name: sam_spicsnumber, sam_spiselect, sam_spistatus, and sam_spicmddata + * + * Description: + * These external functions must be provided by board-specific logic. They + * include: + * + * o sam_spicsnumber and sam_spiselect which are helper functions to + * manage the board-specific aspects of the unique SAM3/4 chip select + * architecture. + * o sam_spistatus and sam_spicmddata: Implementations of the status + * and cmddata methods of the SPI interface defined by struct spi_ops_ + * (see include/nuttx/spi.h). All other methods including + * up_spiinitialize()) 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_spicsnumber(), sam_spiselect() and sam_spistatus() + * 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_spicmddata() 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 up_spiinitialize() in your low level application + * initialization logic + * 4. The handle returned by up_spiinitialize() 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). + * + ****************************************************************************/ + +#ifdef CONFIG_SAM34_SPI +struct spi_dev_s; +enum spi_dev_e; + +/**************************************************************************** + * Name: sam_spicsnumber + * + * Description: + * The SAM3/4 has 4 CS registers for controlling device features. This + * function must be provided by board-specific code. Given a logical device + * ID, this function returns a number from 0 to 3 that identifies one of + * these SAM3/4 CS resources. + * + * If CONFIG_SPI_OWNBUS is not defined and the GPIO is controlled by + * sam_spiselect, then the same CS register may be used to control + * multiple devices. + * + * Input Parameters: + * dev - SPI device info + * devid - Identifies the (logical) device + * + * Returned Values: + * On success, a CS number from 0 to 3 is returned; A negated errno may + * be returned on a failure. + * + ****************************************************************************/ + +int sam_spicsnumber(enum spi_dev_e devid); + +/**************************************************************************** + * Name: sam_spiselect + * + * 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: + * dev - SPI device info + * devid - Identifies the (logical) device + * selected - TRUE:Select the device, FALSE:De-select the device + * + * Returned Values: + * None + * + ****************************************************************************/ + +void sam_spiselect(enum spi_dev_e devid, bool selected); + +/**************************************************************************** + * Name: sam_spistatus + * + * Description: + * Return status information associated with the SPI device. + * + * Input Parameters: + * dev - SPI device info + * devid - Identifies the (logical) device + * + * Returned Values: + * Bit-encoded SPI status (see include/nuttx/spi.h. + * + ****************************************************************************/ + +uint8_t sam_spistatus(FAR struct spi_dev_s *dev, enum spi_dev_e devid); + +/**************************************************************************** + * Name: sam_spicmddata + * + * Description: + * Some SPI devices require an additional control to determine if the SPI + * data being sent is a command or is data. If CONFIG_SPI_CMDDATA then + * this function will be called to different be command and data transfers. + * + * This is often needed, for example, by LCD drivers. Some LCD hardware + * may be configured to use 9-bit data transfers with the 9th bit + * indicating command or data. That same hardware may be configurable, + * instead, to use 8-bit data but to require an additional, board- + * specific GPIO control to distinguish command and data. This function + * would be needed in that latter case. + * + * Input Parameters: + * dev - SPI device info + * devid - Identifies the (logical) device + * + * Returned Values: + * Zero on success; a negated errno on failure. + * + ****************************************************************************/ + +#ifdef CONFIG_SPI_CMDDATA +int sam_spicmddata(FAR struct spi_dev_s *dev, enum spi_dev_e devid, bool cmd); +#endif +#endif /* CONFIG_SAM34_SPI */ + +#undef EXTERN +#if defined(__cplusplus) +} +#endif + +#endif /* __ASSEMBLY__ */ +#endif /* __ARCH_ARM_SRC_SAM34_SAM_SPI_H */ |