dma.h

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/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_DRIVERS_DMA_H_
#define ZEPHYR_INCLUDE_DRIVERS_DMA_H_
 
#include <kernel.h>
#include <device.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
 
enum dma_channel_direction {
        MEMORY_TO_MEMORY = 0x0,
        MEMORY_TO_PERIPHERAL,
        PERIPHERAL_TO_MEMORY,
        PERIPHERAL_TO_PERIPHERAL /*only supported in NXP EDMA*/
};
 
enum dma_addr_adj {
        DMA_ADDR_ADJ_INCREMENT,
        DMA_ADDR_ADJ_DECREMENT,
        DMA_ADDR_ADJ_NO_CHANGE,
};
 
/* channel attributes */
enum dma_channel_filter {
        DMA_CHANNEL_NORMAL, /* normal DMA channel */
        DMA_CHANNEL_PERIODIC, /* can be triggerred by periodic sources */
};
 
struct dma_block_config {
#ifdef CONFIG_DMA_64BIT
        uint64_t source_address;
        uint64_t dest_address;
#else
        uint32_t source_address;
        uint32_t dest_address;
#endif
        uint32_t source_gather_interval;
        uint32_t dest_scatter_interval;
        uint16_t dest_scatter_count;
        uint16_t source_gather_count;
        uint32_t block_size;
        struct dma_block_config *next_block;
        uint16_t  source_gather_en :  1;
        uint16_t  dest_scatter_en :   1;
        uint16_t  source_addr_adj :   2;
        uint16_t  dest_addr_adj :     2;
        uint16_t  source_reload_en :  1;
        uint16_t  dest_reload_en :    1;
        uint16_t  fifo_mode_control : 4;
        uint16_t  flow_control_mode : 1;
        uint16_t  reserved :          3;
};
 
typedef void (*dma_callback_t)(const struct device *dev, void *user_data,
                               uint32_t channel, int status);
 
struct dma_config {
        uint32_t  dma_slot :             7;
        uint32_t  channel_direction :    3;
        uint32_t  complete_callback_en : 1;
        uint32_t  error_callback_en :    1;
        uint32_t  source_handshake :     1;
        uint32_t  dest_handshake :       1;
        uint32_t  channel_priority :     4;
        uint32_t  source_chaining_en :   1;
        uint32_t  dest_chaining_en :     1;
        uint32_t  linked_channel   :     7;
        uint32_t  reserved :             5;
        uint32_t  source_data_size :    16;
        uint32_t  dest_data_size :      16;
        uint32_t  source_burst_length : 16;
        uint32_t  dest_burst_length :   16;
        uint32_t block_count;
        struct dma_block_config *head_block;
        void *user_data;
        dma_callback_t dma_callback;
};
 
struct dma_status {
        bool busy;
        enum dma_channel_direction dir;
        uint32_t pending_length;
};
 
struct dma_context {
        int32_t magic;
        int dma_channels;
        atomic_t *atomic;
};
 
/* magic code to identify context content */
#define DMA_MAGIC 0x47494749
 
typedef int (*dma_api_config)(const struct device *dev, uint32_t channel,
                              struct dma_config *config);
 
#ifdef CONFIG_DMA_64BIT
typedef int (*dma_api_reload)(const struct device *dev, uint32_t channel,
                              uint64_t src, uint64_t dst, size_t size);
#else
typedef int (*dma_api_reload)(const struct device *dev, uint32_t channel,
                              uint32_t src, uint32_t dst, size_t size);
#endif
 
typedef int (*dma_api_start)(const struct device *dev, uint32_t channel);
 
typedef int (*dma_api_stop)(const struct device *dev, uint32_t channel);
 
typedef int (*dma_api_get_status)(const struct device *dev, uint32_t channel,
                                  struct dma_status *status);
 
typedef bool (*dma_api_chan_filter)(const struct device *dev,
                                int channel, void *filter_param);
 
__subsystem struct dma_driver_api {
        dma_api_config config;
        dma_api_reload reload;
        dma_api_start start;
        dma_api_stop stop;
        dma_api_get_status get_status;
        dma_api_chan_filter chan_filter;
};
static inline int dma_config(const struct device *dev, uint32_t channel,
                             struct dma_config *config)
{
        const struct dma_driver_api *api =
                (const struct dma_driver_api *)dev->api;
 
        return api->config(dev, channel, config);
}
 
#ifdef CONFIG_DMA_64BIT
static inline int dma_reload(const struct device *dev, uint32_t channel,
                             uint64_t src, uint64_t dst, size_t size)
#else
static inline int dma_reload(const struct device *dev, uint32_t channel,
                uint32_t src, uint32_t dst, size_t size)
#endif
{
        const struct dma_driver_api *api =
                (const struct dma_driver_api *)dev->api;
 
        if (api->reload) {
                return api->reload(dev, channel, src, dst, size);
        }
 
        return -ENOSYS;
}
 
__syscall int dma_start(const struct device *dev, uint32_t channel);
 
static inline int z_impl_dma_start(const struct device *dev, uint32_t channel)
{
        const struct dma_driver_api *api =
                (const struct dma_driver_api *)dev->api;
 
        return api->start(dev, channel);
}
 
__syscall int dma_stop(const struct device *dev, uint32_t channel);
 
static inline int z_impl_dma_stop(const struct device *dev, uint32_t channel)
{
        const struct dma_driver_api *api =
                (const struct dma_driver_api *)dev->api;
 
        return api->stop(dev, channel);
}
 
__syscall int dma_request_channel(const struct device *dev,
                                  void *filter_param);
 
static inline int z_impl_dma_request_channel(const struct device *dev,
                                             void *filter_param)
{
        int i = 0;
        int channel = -EINVAL;
        const struct dma_driver_api *api =
                (const struct dma_driver_api *)dev->api;
        /* dma_context shall be the first one in dev data */
        struct dma_context *dma_ctx = (struct dma_context *)dev->data;
 
        if (dma_ctx->magic != DMA_MAGIC) {
                return channel;
        }
 
        for (i = 0; i < dma_ctx->dma_channels; i++) {
                if (!atomic_test_and_set_bit(dma_ctx->atomic, i)) {
                        channel = i;
                        if (api->chan_filter &&
                            !api->chan_filter(dev, channel, filter_param)) {
                                atomic_clear_bit(dma_ctx->atomic, channel);
                                continue;
                        }
                        break;
                }
        }
 
        return channel;
}
 
__syscall void dma_release_channel(const struct device *dev,
                                   uint32_t channel);
 
static inline void z_impl_dma_release_channel(const struct device *dev,
                                              uint32_t channel)
{
        struct dma_context *dma_ctx = (struct dma_context *)dev->data;
 
        if (dma_ctx->magic != DMA_MAGIC) {
                return;
        }
 
        if (channel < dma_ctx->dma_channels) {
                atomic_clear_bit(dma_ctx->atomic, channel);
        }
 
}
 
__syscall int dma_chan_filter(const struct device *dev,
                                   int channel, void *filter_param);
 
static inline int z_impl_dma_chan_filter(const struct device *dev,
                                              int channel, void *filter_param)
{
        const struct dma_driver_api *api =
                (const struct dma_driver_api *)dev->api;
 
        if (api->chan_filter) {
                return api->chan_filter(dev, channel, filter_param);
        }
 
        return -ENOSYS;
}
 
static inline int dma_get_status(const struct device *dev, uint32_t channel,
                                 struct dma_status *stat)
{
        const struct dma_driver_api *api =
                (const struct dma_driver_api *)dev->api;
 
        if (api->get_status) {
                return api->get_status(dev, channel, stat);
        }
 
        return -ENOSYS;
}
 
static inline uint32_t dma_width_index(uint32_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);
}
 
static inline uint32_t dma_burst_index(uint32_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_DRIVERS_DMA_H_ */