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/**
* @file
*
* @brief Public APIs for the DMA drivers.
*/
/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_DMA_H_
#define ZEPHYR_INCLUDE_DMA_H_
#include <kernel.h>
#include <device.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief DMA Interface
* @defgroup dma_interface DMA Interface
* @ingroup io_interfaces
* @{
*/
enum dma_channel_direction {
MEMORY_TO_MEMORY = 0x0,
MEMORY_TO_PERIPHERAL,
PERIPHERAL_TO_MEMORY
};
/** Valid values for @a source_addr_adj and @a dest_addr_adj */
enum dma_addr_adj {
DMA_ADDR_ADJ_INCREMENT,
DMA_ADDR_ADJ_DECREMENT,
DMA_ADDR_ADJ_NO_CHANGE,
};
/**
* @brief DMA block configuration structure.
*
* source_address is block starting address at source
* source_gather_interval is the address adjustment at gather boundary
* dest_address is block starting address at destination
* dest_scatter_interval is the address adjustment at scatter boundary
* dest_scatter_count is the continuous transfer count between scatter
* boundaries
* source_gather_count is the continuous transfer count between gather
* boundaries
* block_size is the number of bytes to be transferred for this block.
*
* config is a bit field with the following parts:
* source_gather_en [ 0 ] - 0-disable, 1-enable
* dest_scatter_en [ 1 ] - 0-disable, 1-enable
* source_addr_adj [ 2 : 3 ] - 00-increment, 01-decrement,
* 10-no change
* dest_addr_adj [ 4 : 5 ] - 00-increment, 01-decrement,
* 10-no change
* source_reload_en [ 6 ] - reload source address at the end of
* block transfer
* 0-disable, 1-enable
* dest_reload_en [ 7 ] - reload destination address at the end
* of block transfer
* 0-disable, 1-enable
* fifo_mode_control [ 8 : 11 ] - How full of the fifo before transfer
* start. HW specific.
* flow_control_mode [ 12 ] - 0-source request served upon data
* availability
* 1-source request postponed until
* destination request happens
* reserved [ 13 : 15 ]
*/
struct dma_block_config {
u32_t source_address;
u32_t source_gather_interval;
u32_t dest_address;
u32_t dest_scatter_interval;
u16_t dest_scatter_count;
u16_t source_gather_count;
u32_t block_size;
struct dma_block_config *next_block;
u16_t source_gather_en : 1;
u16_t dest_scatter_en : 1;
u16_t source_addr_adj : 2;
u16_t dest_addr_adj : 2;
u16_t source_reload_en : 1;
u16_t dest_reload_en : 1;
u16_t fifo_mode_control : 4;
u16_t flow_control_mode : 1;
u16_t reserved : 3;
};
/**
* @brief DMA configuration structure.
*
* dma_slot [ 0 : 5 ] - which peripheral and direction
* (HW specific)
* channel_direction [ 6 : 8 ] - 000-memory to memory, 001-memory to
* peripheral, 010-peripheral to memory,
* ...
* complete_callback_en [ 9 ] - 0-callback invoked at completion only
* 1-callback invoked at completion of
* each block
* error_callback_en [ 10 ] - 0-error callback enabled
* 1-error callback disabled
* source_handshake [ 11 ] - 0-HW, 1-SW
* dest_handshake [ 12 ] - 0-HW, 1-SW
* channel_priority [ 13 : 16 ] - DMA channel priority
* source_chaining_en [ 17 ] - enable/disable source block chaining
* 0-disable, 1-enable
* dest_chaining_en [ 18 ] - enable/disable destination block
* chaining.
* 0-disable, 1-enable
* reserved [ 19 : 31 ]
*
* source_data_size [ 0 : 15 ] - width of source data (in bytes)
* dest_data_size [ 16 : 31 ] - width of dest data (in bytes)
* source_burst_length [ 0 : 15 ] - number of source data units
* dest_burst_length [ 16 : 31 ] - number of destination data units
*
* block_count is the number of blocks used for block chaining, this
* depends on availability of the DMA controller.
*
* callback_arg private argument from DMA client.
*
* dma_callback is the callback function pointer. If enabled, callback function
* will be invoked at transfer completion or when error happens
* (error_code: zero-transfer success, non zero-error happens).
*/
struct dma_config {
u32_t dma_slot : 6;
u32_t channel_direction : 3;
u32_t complete_callback_en : 1;
u32_t error_callback_en : 1;
u32_t source_handshake : 1;
u32_t dest_handshake : 1;
u32_t channel_priority : 4;
u32_t source_chaining_en : 1;
u32_t dest_chaining_en : 1;
u32_t reserved : 13;
u32_t source_data_size : 16;
u32_t dest_data_size : 16;
u32_t source_burst_length : 16;
u32_t dest_burst_length : 16;
u32_t block_count;
struct dma_block_config *head_block;
void *callback_arg;
void (*dma_callback)(void *callback_arg, u32_t channel,
int error_code);
};
/**
* @cond INTERNAL_HIDDEN
*
* These are for internal use only, so skip these in
* public documentation.
*/
typedef int (*dma_api_config)(struct device *dev, u32_t channel,
struct dma_config *config);
typedef int (*dma_api_reload)(struct device *dev, u32_t channel,
u32_t src, u32_t dst, size_t size);
typedef int (*dma_api_start)(struct device *dev, u32_t channel);
typedef int (*dma_api_stop)(struct device *dev, u32_t channel);
struct dma_driver_api {
dma_api_config config;
dma_api_reload reload;
dma_api_start start;
dma_api_stop stop;
};
/**
* @endcond
*/
/**
* @brief Configure individual channel for DMA transfer.
*
* @param dev Pointer to the device structure for the driver instance.
* @param channel Numeric identification of the channel to configure
* @param config Data structure containing the intended configuration for the
* selected channel
*
* @retval 0 if successful.
* @retval Negative errno code if failure.
*/
static inline int dma_config(struct device *dev, u32_t channel,
struct dma_config *config)
{
const struct dma_driver_api *api =
(const struct dma_driver_api *)dev->driver_api;
return api->config(dev, channel, config);
}
/**
* @brief Reload buffer(s) for a DMA channel
*
* @param dev Pointer to the device structure for the driver instance.
* @param channel Numeric identification of the channel to configure
* selected channel
* @param src source address for the DMA transfer
* @param dst destination address for the DMA transfer
* @param size size of DMA transfer
*
* @retval 0 if successful.
* @retval Negative errno code if failure.
*/
static inline int dma_reload(struct device *dev, u32_t channel,
u32_t src, u32_t dst, size_t size)
{
const struct dma_driver_api *api =
(const struct dma_driver_api *)dev->driver_api;
return api->reload(dev, channel, src, dst, size);
}
/**
* @brief Enables DMA channel and starts the transfer, the channel must be
* configured beforehand.
*
* Implementations must check the validity of the channel ID passed in and
* return -EINVAL if it is invalid.
*
* @param dev Pointer to the device structure for the driver instance.
* @param channel Numeric identification of the channel where the transfer will
* be processed
*
* @retval 0 if successful.
* @retval Negative errno code if failure.
*/
__syscall int dma_start(struct device *dev, u32_t channel);
static inline int _impl_dma_start(struct device *dev, u32_t channel)
{
const struct dma_driver_api *api =
(const struct dma_driver_api *)dev->driver_api;
return api->start(dev, channel);
}
/**
* @brief Stops the DMA transfer and disables the channel.
*
* Implementations must check the validity of the channel ID passed in and
* return -EINVAL if it is invalid.
*
* @param dev Pointer to the device structure for the driver instance.
* @param channel Numeric identification of the channel where the transfer was
* being processed
*
* @retval 0 if successful.
* @retval Negative errno code if failure.
*/
__syscall int dma_stop(struct device *dev, u32_t channel);
static inline int _impl_dma_stop(struct device *dev, u32_t channel)
{
const struct dma_driver_api *api =
(const struct dma_driver_api *)dev->driver_api;
return api->stop(dev, channel);
}
/**
* @brief Look-up generic width index to be used in registers
*
* WARNING: This look-up works for most controllers, but *may* not work for
* yours. Ensure your controller expects the most common register
* bit values before using this convenience function. If your
* controller does not support these values, you will have to write
* your own look-up inside the controller driver.
*
* @param size: width of bus (in bytes)
*
* @retval common DMA index to be placed into registers.
*/
static inline u32_t dma_width_index(u32_t size)
{
/* Check boundaries (max supported width is 32 Bytes) */
if (size < 1 || size > 32) {
return 0; /* Zero is the default (8 Bytes) */
}
/* Ensure size is a power of 2 */
if (!is_power_of_two(size)) {
return 0; /* Zero is the default (8 Bytes) */
}
/* Convert to bit pattern for writing to a register */
return find_msb_set(size);
}
/**
* @brief Look-up generic burst index to be used in registers
*
* WARNING: This look-up works for most controllers, but *may* not work for
* yours. Ensure your controller expects the most common register
* bit values before using this convenience function. If your
* controller does not support these values, you will have to write
* your own look-up inside the controller driver.
*
* @param burst: number of bytes to be sent in a single burst
*
* @retval common DMA index to be placed into registers.
*/
static inline u32_t dma_burst_index(u32_t burst)
{
/* Check boundaries (max supported burst length is 256) */
if (burst < 1 || burst > 256) {
return 0; /* Zero is the default (1 burst length) */
}
/* Ensure burst is a power of 2 */
if (!(burst & (burst - 1))) {
return 0; /* Zero is the default (1 burst length) */
}
/* Convert to bit pattern for writing to a register */
return find_msb_set(burst);
}
/**
* @}
*/
#ifdef __cplusplus
}
#endif
#include <syscalls/dma.h>
#endif /* ZEPHYR_INCLUDE_DMA_H_ */