linux-stable/include/linux/of_dma.h
Alexander Popov 16369efb1f dmaengine: of: add common xlate function for matching by channel id
This patch adds a new common OF dma xlate callback function which will match a
channel by it's id. The binding expects one integer argument which it will use to
lookup the channel by the id.

Unlike of_dma_simple_xlate this function is able to handle a system with
multiple DMA controllers. When registering the of dma provider with
of_dma_controller_register a pointer to the dma_device struct which is
associated with the dt node needs to passed as the data parameter.
New function will use this pointer to match only channels which belong to the
specified DMA controller.

Signed-off-by: Alexander Popov <a13xp0p0v88@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2014-07-26 00:21:41 +05:30

75 lines
1.9 KiB
C

/*
* OF helpers for DMA request / controller
*
* Based on of_gpio.h
*
* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __LINUX_OF_DMA_H
#define __LINUX_OF_DMA_H
#include <linux/of.h>
#include <linux/dmaengine.h>
struct device_node;
struct of_dma {
struct list_head of_dma_controllers;
struct device_node *of_node;
struct dma_chan *(*of_dma_xlate)
(struct of_phandle_args *, struct of_dma *);
void *of_dma_data;
};
struct of_dma_filter_info {
dma_cap_mask_t dma_cap;
dma_filter_fn filter_fn;
};
#ifdef CONFIG_OF
extern int of_dma_controller_register(struct device_node *np,
struct dma_chan *(*of_dma_xlate)
(struct of_phandle_args *, struct of_dma *),
void *data);
extern void of_dma_controller_free(struct device_node *np);
extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
const char *name);
extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma);
extern struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec,
struct of_dma *ofdma);
#else
static inline int of_dma_controller_register(struct device_node *np,
struct dma_chan *(*of_dma_xlate)
(struct of_phandle_args *, struct of_dma *),
void *data)
{
return -ENODEV;
}
static inline void of_dma_controller_free(struct device_node *np)
{
}
static inline struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
const char *name)
{
return NULL;
}
static inline struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
return NULL;
}
#define of_dma_xlate_by_chan_id NULL
#endif
#endif /* __LINUX_OF_DMA_H */