forked from mirrors/linux
bb8822cbbc
This patch adds a generic DMA API to implement DMA support for i2c-stm32fx drivers Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
58 lines
1.6 KiB
C
58 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* i2c-stm32.h
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*
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* Copyright (C) M'boumba Cedric Madianga 2017
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* Copyright (C) STMicroelectronics 2017
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* Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
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*
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*/
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#ifndef _I2C_STM32_H
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#define _I2C_STM32_H
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#include <linux/dma-direction.h>
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#include <linux/dmaengine.h>
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#include <linux/dma-mapping.h>
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enum stm32_i2c_speed {
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STM32_I2C_SPEED_STANDARD, /* 100 kHz */
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STM32_I2C_SPEED_FAST, /* 400 kHz */
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STM32_I2C_SPEED_FAST_PLUS, /* 1 MHz */
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STM32_I2C_SPEED_END,
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};
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/**
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* struct stm32_i2c_dma - DMA specific data
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* @chan_tx: dma channel for TX transfer
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* @chan_rx: dma channel for RX transfer
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* @chan_using: dma channel used for the current transfer (TX or RX)
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* @dma_buf: dma buffer
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* @dma_len: dma buffer len
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* @dma_transfer_dir: dma transfer direction indicator
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* @dma_data_dir: dma transfer mode indicator
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* @dma_complete: dma transfer completion
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*/
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struct stm32_i2c_dma {
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struct dma_chan *chan_tx;
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struct dma_chan *chan_rx;
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struct dma_chan *chan_using;
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dma_addr_t dma_buf;
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unsigned int dma_len;
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enum dma_transfer_direction dma_transfer_dir;
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enum dma_data_direction dma_data_dir;
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struct completion dma_complete;
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};
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struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
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dma_addr_t phy_addr,
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u32 txdr_offset, u32 rxdr_offset);
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void stm32_i2c_dma_free(struct stm32_i2c_dma *dma);
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int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
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bool rd_wr, u32 len, u8 *buf,
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dma_async_tx_callback callback,
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void *dma_async_param);
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#endif /* _I2C_STM32_H */
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