mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-30 08:31:03 +00:00
185f812c41
Sphinx expects Return: and not @return to indicate a return value.
find . -name '*.c' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;
find . -name '*.h' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
345 lines
11 KiB
C
345 lines
11 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
|
|
/*
|
|
* Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
|
|
* Copyright (C) 2015 - 2018 Texas Instruments Incorporated <www.ti.com>
|
|
* Written by Mugunthan V N <mugunthanvnm@ti.com>
|
|
*
|
|
*/
|
|
|
|
#ifndef _DMA_H_
|
|
#define _DMA_H_
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/types.h>
|
|
|
|
struct udevice;
|
|
|
|
/*
|
|
* enum dma_direction - dma transfer direction indicator
|
|
* @DMA_MEM_TO_MEM: Memcpy mode
|
|
* @DMA_MEM_TO_DEV: From Memory to Device
|
|
* @DMA_DEV_TO_MEM: From Device to Memory
|
|
* @DMA_DEV_TO_DEV: From Device to Device
|
|
*/
|
|
enum dma_direction {
|
|
DMA_MEM_TO_MEM,
|
|
DMA_MEM_TO_DEV,
|
|
DMA_DEV_TO_MEM,
|
|
DMA_DEV_TO_DEV,
|
|
};
|
|
|
|
#define DMA_SUPPORTS_MEM_TO_MEM BIT(0)
|
|
#define DMA_SUPPORTS_MEM_TO_DEV BIT(1)
|
|
#define DMA_SUPPORTS_DEV_TO_MEM BIT(2)
|
|
#define DMA_SUPPORTS_DEV_TO_DEV BIT(3)
|
|
|
|
/*
|
|
* struct dma_dev_priv - information about a device used by the uclass
|
|
*
|
|
* @supported: mode of transfers that DMA can support, should be
|
|
* one/multiple of DMA_SUPPORTS_*
|
|
*/
|
|
struct dma_dev_priv {
|
|
u32 supported;
|
|
};
|
|
|
|
#ifdef CONFIG_DMA_CHANNELS
|
|
/**
|
|
* A DMA is a feature of computer systems that allows certain hardware
|
|
* subsystems to access main system memory, independent of the CPU.
|
|
* DMA channels are typically generated externally to the HW module
|
|
* consuming them, by an entity this API calls a DMA provider. This API
|
|
* provides a standard means for drivers to enable and disable DMAs, and to
|
|
* copy, send and receive data using DMA.
|
|
*
|
|
* A driver that implements UCLASS_DMA is a DMA provider. A provider will
|
|
* often implement multiple separate DMAs, since the hardware it manages
|
|
* often has this capability. dma_uclass.h describes the interface which
|
|
* DMA providers must implement.
|
|
*
|
|
* DMA consumers/clients are the HW modules driven by the DMA channels. This
|
|
* header file describes the API used by drivers for those HW modules.
|
|
*
|
|
* DMA consumer DMA_MEM_TO_DEV (transmit) usage example (based on networking).
|
|
* Note. dma_send() is sync operation always - it'll start transfer and will
|
|
* poll for it to complete:
|
|
* - get/request dma channel
|
|
* struct dma dma_tx;
|
|
* ret = dma_get_by_name(common->dev, "tx0", &dma_tx);
|
|
* if (ret) ...
|
|
*
|
|
* - enable dma channel
|
|
* ret = dma_enable(&dma_tx);
|
|
* if (ret) ...
|
|
*
|
|
* - dma transmit DMA_MEM_TO_DEV.
|
|
* struct ti_drv_packet_data packet_data;
|
|
*
|
|
* packet_data.opt1 = val1;
|
|
* packet_data.opt2 = val2;
|
|
* ret = dma_send(&dma_tx, packet, length, &packet_data);
|
|
* if (ret) ..
|
|
*
|
|
* DMA consumer DMA_DEV_TO_MEM (receive) usage example (based on networking).
|
|
* Note. dma_receive() is sync operation always - it'll start transfer
|
|
* (if required) and will poll for it to complete (or for any previously
|
|
* configured dev2mem transfer to complete):
|
|
* - get/request dma channel
|
|
* struct dma dma_rx;
|
|
* ret = dma_get_by_name(common->dev, "rx0", &dma_rx);
|
|
* if (ret) ...
|
|
*
|
|
* - enable dma channel
|
|
* ret = dma_enable(&dma_rx);
|
|
* if (ret) ...
|
|
*
|
|
* - dma receive DMA_DEV_TO_MEM.
|
|
* struct ti_drv_packet_data packet_data;
|
|
*
|
|
* len = dma_receive(&dma_rx, (void **)packet, &packet_data);
|
|
* if (ret < 0) ...
|
|
*
|
|
* DMA consumer DMA_DEV_TO_MEM (receive) zero-copy usage example (based on
|
|
* networking). Networking subsystem allows to configure and use few receive
|
|
* buffers (dev2mem), as Networking RX DMA channels usually implemented
|
|
* as streaming interface
|
|
* - get/request dma channel
|
|
* struct dma dma_rx;
|
|
* ret = dma_get_by_name(common->dev, "rx0", &dma_rx);
|
|
* if (ret) ...
|
|
*
|
|
* for (i = 0; i < RX_DESC_NUM; i++) {
|
|
* ret = dma_prepare_rcv_buf(&dma_rx,
|
|
* net_rx_packets[i],
|
|
* RX_BUF_SIZE);
|
|
* if (ret) ...
|
|
* }
|
|
*
|
|
* - enable dma channel
|
|
* ret = dma_enable(&dma_rx);
|
|
* if (ret) ...
|
|
*
|
|
* - dma receive DMA_DEV_TO_MEM.
|
|
* struct ti_drv_packet_data packet_data;
|
|
*
|
|
* len = dma_receive(&dma_rx, (void **)packet, &packet_data);
|
|
* if (ret < 0) ..
|
|
*
|
|
* -- process packet --
|
|
*
|
|
* - return buffer back to DAM channel
|
|
* ret = dma_prepare_rcv_buf(&dma_rx,
|
|
* net_rx_packets[rx_next],
|
|
* RX_BUF_SIZE);
|
|
*/
|
|
|
|
struct udevice;
|
|
|
|
/**
|
|
* struct dma - A handle to (allowing control of) a single DMA.
|
|
*
|
|
* Clients provide storage for DMA handles. The content of the structure is
|
|
* managed solely by the DMA API and DMA drivers. A DMA struct is
|
|
* initialized by "get"ing the DMA struct. The DMA struct is passed to all
|
|
* other DMA APIs to identify which DMA channel to operate upon.
|
|
*
|
|
* @dev: The device which implements the DMA channel.
|
|
* @id: The DMA channel ID within the provider.
|
|
*
|
|
* Currently, the DMA API assumes that a single integer ID is enough to
|
|
* identify and configure any DMA channel for any DMA provider. If this
|
|
* assumption becomes invalid in the future, the struct could be expanded to
|
|
* either (a) add more fields to allow DMA providers to store additional
|
|
* information, or (b) replace the id field with an opaque pointer, which the
|
|
* provider would dynamically allocated during its .of_xlate op, and process
|
|
* during is .request op. This may require the addition of an extra op to clean
|
|
* up the allocation.
|
|
*/
|
|
struct dma {
|
|
struct udevice *dev;
|
|
/*
|
|
* Written by of_xlate. We assume a single id is enough for now. In the
|
|
* future, we might add more fields here.
|
|
*/
|
|
unsigned long id;
|
|
};
|
|
|
|
# if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(DMA)
|
|
/**
|
|
* dma_get_by_index - Get/request a DMA by integer index.
|
|
*
|
|
* This looks up and requests a DMA. The index is relative to the client
|
|
* device; each device is assumed to have n DMAs associated with it somehow,
|
|
* and this function finds and requests one of them. The mapping of client
|
|
* device DMA indices to provider DMAs may be via device-tree properties,
|
|
* board-provided mapping tables, or some other mechanism.
|
|
*
|
|
* @dev: The client device.
|
|
* @index: The index of the DMA to request, within the client's list of
|
|
* DMA channels.
|
|
* @dma: A pointer to a DMA struct to initialize.
|
|
* Return: 0 if OK, or a negative error code.
|
|
*/
|
|
int dma_get_by_index(struct udevice *dev, int index, struct dma *dma);
|
|
|
|
/**
|
|
* dma_get_by_name - Get/request a DMA by name.
|
|
*
|
|
* This looks up and requests a DMA. The name is relative to the client
|
|
* device; each device is assumed to have n DMAs associated with it somehow,
|
|
* and this function finds and requests one of them. The mapping of client
|
|
* device DMA names to provider DMAs may be via device-tree properties,
|
|
* board-provided mapping tables, or some other mechanism.
|
|
*
|
|
* @dev: The client device.
|
|
* @name: The name of the DMA to request, within the client's list of
|
|
* DMA channels.
|
|
* @dma: A pointer to a DMA struct to initialize.
|
|
* Return: 0 if OK, or a negative error code.
|
|
*/
|
|
int dma_get_by_name(struct udevice *dev, const char *name, struct dma *dma);
|
|
# else
|
|
static inline int dma_get_by_index(struct udevice *dev, int index,
|
|
struct dma *dma)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static inline int dma_get_by_name(struct udevice *dev, const char *name,
|
|
struct dma *dma)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
# endif
|
|
|
|
/**
|
|
* dma_request - Request a DMA by provider-specific ID.
|
|
*
|
|
* This requests a DMA using a provider-specific ID. Generally, this function
|
|
* should not be used, since dma_get_by_index/name() provide an interface that
|
|
* better separates clients from intimate knowledge of DMA providers.
|
|
* However, this function may be useful in core SoC-specific code.
|
|
*
|
|
* @dev: The DMA provider device.
|
|
* @dma: A pointer to a DMA struct to initialize. The caller must
|
|
* have already initialized any field in this struct which the
|
|
* DMA provider uses to identify the DMA channel.
|
|
* Return: 0 if OK, or a negative error code.
|
|
*/
|
|
int dma_request(struct udevice *dev, struct dma *dma);
|
|
|
|
/**
|
|
* dma_free - Free a previously requested DMA.
|
|
*
|
|
* @dma: A DMA struct that was previously successfully requested by
|
|
* dma_request/get_by_*().
|
|
* Return: 0 if OK, or a negative error code.
|
|
*/
|
|
int dma_free(struct dma *dma);
|
|
|
|
/**
|
|
* dma_enable() - Enable (turn on) a DMA channel.
|
|
*
|
|
* @dma: A DMA struct that was previously successfully requested by
|
|
* dma_request/get_by_*().
|
|
* Return: zero on success, or -ve error code.
|
|
*/
|
|
int dma_enable(struct dma *dma);
|
|
|
|
/**
|
|
* dma_disable() - Disable (turn off) a DMA channel.
|
|
*
|
|
* @dma: A DMA struct that was previously successfully requested by
|
|
* dma_request/get_by_*().
|
|
* Return: zero on success, or -ve error code.
|
|
*/
|
|
int dma_disable(struct dma *dma);
|
|
|
|
/**
|
|
* dma_prepare_rcv_buf() - Prepare/add receive DMA buffer.
|
|
*
|
|
* It allows to implement zero-copy async DMA_DEV_TO_MEM (receive) transactions
|
|
* if supported by DMA providers.
|
|
*
|
|
* @dma: A DMA struct that was previously successfully requested by
|
|
* dma_request/get_by_*().
|
|
* @dst: The receive buffer pointer.
|
|
* @size: The receive buffer size
|
|
* Return: zero on success, or -ve error code.
|
|
*/
|
|
int dma_prepare_rcv_buf(struct dma *dma, void *dst, size_t size);
|
|
|
|
/**
|
|
* dma_receive() - Receive a DMA transfer.
|
|
*
|
|
* @dma: A DMA struct that was previously successfully requested by
|
|
* dma_request/get_by_*().
|
|
* @dst: The destination pointer.
|
|
* @metadata: DMA driver's channel specific data
|
|
* Return: length of received data on success, or zero - no data,
|
|
* or -ve error code.
|
|
*/
|
|
int dma_receive(struct dma *dma, void **dst, void *metadata);
|
|
|
|
/**
|
|
* dma_send() - Send a DMA transfer.
|
|
*
|
|
* @dma: A DMA struct that was previously successfully requested by
|
|
* dma_request/get_by_*().
|
|
* @src: The source pointer.
|
|
* @len: Length of the data to be sent (number of bytes).
|
|
* @metadata: DMA driver's channel specific data
|
|
* Return: zero on success, or -ve error code.
|
|
*/
|
|
int dma_send(struct dma *dma, void *src, size_t len, void *metadata);
|
|
|
|
/**
|
|
* dma_get_cfg() - Get DMA channel configuration for client's use
|
|
*
|
|
* @dma: The DMA Channel to manipulate
|
|
* @cfg_id: DMA provider specific ID to identify what
|
|
* configuration data client needs
|
|
* @cfg_data: Pointer to store pointer to DMA driver specific
|
|
* configuration data for the given cfg_id (output param)
|
|
* Return: zero on success, or -ve error code.
|
|
*/
|
|
int dma_get_cfg(struct dma *dma, u32 cfg_id, void **cfg_data);
|
|
#endif /* CONFIG_DMA_CHANNELS */
|
|
|
|
#if CONFIG_IS_ENABLED(DMA)
|
|
/*
|
|
* dma_get_device - get a DMA device which supports transfer
|
|
* type of transfer_type
|
|
*
|
|
* @transfer_type - transfer type should be one/multiple of
|
|
* DMA_SUPPORTS_*
|
|
* @devp - udevice pointer to return the found device
|
|
* Return: - will return on success and devp will hold the
|
|
* pointer to the device
|
|
*/
|
|
int dma_get_device(u32 transfer_type, struct udevice **devp);
|
|
|
|
/*
|
|
* dma_memcpy - try to use DMA to do a mem copy which will be
|
|
* much faster than CPU mem copy
|
|
*
|
|
* @dst - destination pointer
|
|
* @src - souce pointer
|
|
* @len - data length to be copied
|
|
* Return: - on successful transfer returns no of bytes
|
|
transferred and on failure return error code.
|
|
*/
|
|
int dma_memcpy(void *dst, void *src, size_t len);
|
|
#else
|
|
static inline int dma_get_device(u32 transfer_type, struct udevice **devp)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
|
|
static inline int dma_memcpy(void *dst, void *src, size_t len)
|
|
{
|
|
return -ENOSYS;
|
|
}
|
|
#endif /* CONFIG_DMA */
|
|
#endif /* _DMA_H_ */
|