154 lines
5.0 KiB
C
154 lines
5.0 KiB
C
/****************************************************************************
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* include/nuttx/spi/spi_bitbang.h
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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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#ifndef __INCLUDE_NUTTX_SPI_SPI_BITBANG_H
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#define __INCLUDE_NUTTX_SPI_SPI_BITBANG_H
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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 <nuttx/mutex.h>
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#include <nuttx/spi/spi.h>
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#ifdef CONFIG_SPI_BITBANG
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/****************************************************************************
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* Public Types
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****************************************************************************/
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#ifndef __ASSEMBLY__
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/* These are the lower-half handlers that perform the level-level, platform-
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* specific bit-bang operations.
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*/
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struct spi_bitbang_s; /* Forward reference */
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struct spi_bitbang_ops_s
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{
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/* Platform specific chip select logic */
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void (*select)(FAR struct spi_bitbang_s *priv, uint32_t devid,
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bool selected);
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/* Platform-specific, SPI frequency function */
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uint32_t (*setfrequency)(FAR struct spi_bitbang_s *priv,
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uint32_t frequency);
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/* Platform-specific, SPI mode function */
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void (*setmode)(FAR struct spi_bitbang_s *priv, enum spi_mode_e mode);
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/* Platform-specific word exchange function */
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uint16_t (*exchange)(FAR struct spi_bitbang_s *priv, uint16_t dataout);
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/* Platform-specific word exchange function */
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uint8_t (*status)(FAR struct spi_bitbang_s *priv, uint32_t devid);
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#ifdef CONFIG_SPI_CMDDATA
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/* Platform-specific CMD/DATA function */
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int (*cmddata)(FAR struct spi_bitbang_s *priv, uint32_t devid,
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bool cmd);
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#endif
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};
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/* This is the type of the function that can exchange one bit */
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typedef CODE uint8_t (*bitexchange_t)(uint8_t dataout, uint32_t holdtime);
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/* This structure provides the state of the SPI bit-bang driver */
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struct spi_bitbang_s
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{
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struct spi_dev_s dev; /* Publicly visible version of SPI driver */
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FAR const struct spi_bitbang_ops_s *low; /* Low-level operations */
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uint32_t holdtime; /* SCK hold time to achieve requested frequency */
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bitexchange_t exchange; /* The select bit exchange function */
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mutex_t lock; /* Supports mutually exclusive access to SPI */
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FAR void *priv; /* Private data for instance specific */
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#ifdef CONFIG_SPI_BITBANG_VARWIDTH
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uint8_t nbits; /* Number of bits in the transfer */
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#endif
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};
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/****************************************************************************
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* Public Data
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****************************************************************************/
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#undef EXTERN
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#if defined(__cplusplus)
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#define EXTERN extern "C"
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extern "C"
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{
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#else
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#define EXTERN extern
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#endif
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/****************************************************************************
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* Public Function Prototypes
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****************************************************************************/
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/****************************************************************************
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* Name: spi_create_bitbang
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*
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* Description:
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* Create an instance of the SPI bit-bang driver.
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*
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* Input Parameters:
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* low - Low-level, platform specific device operations.
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* low_priv - Low-level private data, platform specific data.
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*
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* Returned Value:
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* On success a non-NULL, initialized SPI driver instance is returned.
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*
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****************************************************************************/
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FAR struct spi_dev_s *spi_create_bitbang(
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FAR const struct spi_bitbang_ops_s *low,
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FAR void *low_priv);
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/****************************************************************************
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* Name: spi_destroy_bitbang
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*
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* Description:
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* Destroy an instance of the SPI bit-bang driver.
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*
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* Input Parameters:
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* dev - device instance, target driver to destroy.
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*
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****************************************************************************/
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void spi_destroy_bitbang(FAR struct spi_dev_s *dev);
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#undef EXTERN
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#if defined(__cplusplus)
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}
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#endif
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#endif /* __ASSEMBLY__ */
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#endif /* CONFIG_SPI_BITBANG */
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#endif /* __INCLUDE_NUTTX_SPI_SPI_BITBANG_H */
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