drivers/i2c/busses/i2c-stm32.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * i2c-stm32.h
   4  *
   5  * Copyright (C) M'boumba Cedric Madianga 2017
   6  * Copyright (C) STMicroelectronics 2017
   7  * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
   8  *
   9  */
  10
  11 #ifndef _I2C_STM32_H
  12 #define _I2C_STM32_H
  13
  14 #include <linux/dma-direction.h>
  15 #include <linux/dmaengine.h>
  16 #include <linux/dma-mapping.h>
  17
  18 enum stm32_i2c_speed {
  19         STM32_I2C_SPEED_STANDARD, /* 100 kHz */
  20         STM32_I2C_SPEED_FAST, /* 400 kHz */
  21         STM32_I2C_SPEED_FAST_PLUS, /* 1 MHz */
  22         STM32_I2C_SPEED_END,
  23 };
  24
  25 /**
  26  * struct stm32_i2c_dma - DMA specific data
  27  * @chan_tx: dma channel for TX transfer
  28  * @chan_rx: dma channel for RX transfer
  29  * @chan_using: dma channel used for the current transfer (TX or RX)
  30  * @dma_buf: dma buffer
  31  * @dma_len: dma buffer len
  32  * @dma_transfer_dir: dma transfer direction indicator
  33  * @dma_data_dir: dma transfer mode indicator
  34  * @dma_complete: dma transfer completion
  35  */
  36 struct stm32_i2c_dma {
  37         struct dma_chan *chan_tx;
  38         struct dma_chan *chan_rx;
  39         struct dma_chan *chan_using;
  40         dma_addr_t dma_buf;
  41         unsigned int dma_len;
  42         enum dma_transfer_direction dma_transfer_dir;
  43         enum dma_data_direction dma_data_dir;
  44         struct completion dma_complete;
  45 };
  46
  47 struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
  48                                             dma_addr_t phy_addr,
  49                                             u32 txdr_offset, u32 rxdr_offset);
  50
  51 void stm32_i2c_dma_free(struct stm32_i2c_dma *dma);
  52
  53 int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
  54                             bool rd_wr, u32 len, u8 *buf,
  55                             dma_async_tx_callback callback,
  56                             void *dma_async_param);
  57
  58 #endif /* _I2C_STM32_H */