/*
* linux/amba/pl08x.h - ARM PrimeCell DMA Controller driver
*
* Copyright (C) 2005 ARM Ltd
* Copyright (C) 2010 ST-Ericsson SA
*
* 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.
*
* pl08x information required by platform code
*
* Please credit ARM.com
* Documentation: ARM DDI 0196D
*/
#ifndef AMBA_PL08X_H
#define AMBA_PL08X_H
/* We need sizes of structs from this header */
#include <linux/dmaengine.h>
#include <linux/interrupt.h>
struct pl08x_lli;
struct pl08x_driver_data;
/* Bitmasks for selecting AHB ports for DMA transfers */
enum {
PL08X_AHB1 = (1 << 0),
PL08X_AHB2 = (1 << 1)
};
/**
* struct pl08x_channel_data - data structure to pass info between
* platform and PL08x driver regarding channel configuration
* @bus_id: name of this device channel, not just a device name since
* devices may have more than one channel e.g. "foo_tx"
* @min_signal: the minimum DMA signal number to be muxed in for this
* channel (for platforms supporting muxed signals). If you have
* static assignments, make sure this is set to the assigned signal
* number, PL08x have 16 possible signals in number 0 thru 15 so
* when these are not enough they often get muxed (in hardware)
* disabling simultaneous use of the same channel for two devices.
* @max_signal: the maximum DMA signal number to be muxed in for
* the channel. Set to the same as min_signal for
* devices with static assignments
* @muxval: a number usually used to poke into some mux regiser to
* mux in the signal to this channel
* @cctl_opt: default options for the channel control register
* @addr: source/target address in physical memory for this DMA channel,
* can be the address of a FIFO register for burst requests for example.
* This can be left undefined if the PrimeCell API is used for configuring
* this.
* @circular_buffer: whether the buffer passed in is circular and
* shall simply be looped round round (like a record baby round
* round round round)
* @single: the device connected to this channel will request single DMA
* transfers, not bursts. (Bursts are default.)
* @periph_buses: the device connected to this channel is accessible via
* these buses (use PL08X_AHB1 | PL08X_AHB2).
*/
struct pl08x_channel_data {
char *bus_id;
int min_signal;
int max_signal;
u32 muxval;
u32 cctl;
dma_addr_t addr;
bool circular_buffer;
bool single;
u8 periph_buses;
};
/**
* Struct pl08x_bus_data - information of source or destination
* busses for a transfer
* @addr: current address
* @maxwidth: the maximum width of a transfer on this bus
* @buswidth: the width of this bus in bytes: 1, 2 or 4
* @fill_bytes: bytes required to fill to the next bus memory boundary
*/
struct pl08x_bus_data {
dma_addr_t addr;
u8 maxwidth;
u8 buswidth;
size_t fill_bytes;
};
/**
* struct pl08x_phy_chan - holder for the physical channels
* @id: physical index to this channel
* @lock: a lock to use when altering an instance of this struct
* @signal: the physical signal (aka channel) serving this physical channel
* right now
* @serving: the virtual channel currently being served by this physical
* channel
*/
struct pl08x_phy_chan {
unsigned int id;
void __iomem *base;
spinlock_t lock;
int signal;
struct pl08x_dma_chan *serving;
};
/**
* struct pl08x_txd - wrapper for struct dma_async_tx_descriptor
* @llis_bus: DMA memory address (physical) start for the LLIs
* @llis_va: virtual memory address start for the LLIs
*/
struct pl08x_txd {
struct dma_async_tx_descriptor tx;
struct list_head node;
enum dma_data_direction direction;
dma_addr_t src_addr;
dma_addr_t dst_addr;
size_t len;
dma_addr_t llis_bus;
struct pl08x_lli *llis_va;
/* Default cctl value for LLIs */
u32 cctl;
/*
* Settings to be put into the physical channel when we
* trigger this txd. Other registers are in llis_va[0].
*/
u32 ccfg;
};
/**
* struct pl08x_dma_chan_state - holds the PL08x specific virtual channel
* states
* @PL08X_CHAN_IDLE: the channel is idle
* @PL08X_CHAN_RUNNING: the channel has allocated a physical transport
* channel and is running a transfer on it
* @PL08X_CHAN_PAUSED: the channel has allocated a physical transport
* channel, but the transfer is currently paused
* @PL08X_CHAN_WAITING: the channel is waiting for a physical transport
* channel to become available (only pertains to memcpy channels)
*/
enum pl08x_dma_chan_state {
PL08X_CHAN_IDLE,
PL08X_CHAN_RUNNING,
PL08X_CHAN_PAUSED,
PL08X_CHAN_WAITING,
};
/**
* struct pl08x_dma_chan - this structure wraps a DMA ENGINE channel
* @chan: wrappped abstract channel
* @phychan: the physical channel utilized by this channel, if there is one
* @phychan_hold: if non-zero, hold on to the physical channel even if we
* have no pending entries
* @tasklet: tasklet scheduled by the IRQ to handle actual work etc
* @name: name of channel
* @cd: channel platform data
* @runtime_addr: address for RX/TX according to the runtime config
* @runtime_direction: current direction of this channel according to
* runtime config
* @lc: last completed transaction on this channel
* @pend_list: queued transactions pending on this channel
* @at: active transaction on this channel
* @lock: a lock for this channel data
* @host: a pointer to the host (internal use)
* @state: whether the channel is idle, paused, running etc
* @slave: whether this channel is a device (slave) or for memcpy
* @waiting: a TX descriptor on this channel which is waiting for a physical
* channel to become available
*/
struct pl08x_dma_chan {
struct dma_chan chan;
struct pl08x_phy_chan *phychan;
int phychan_hold;
struct tasklet_struct tasklet;
char *name;
struct pl08x_channel_data *cd;
dma_addr_t runtime_addr;
enum dma_data_direction runtime_direction;
dma_cookie_t lc;
struct list_head pend_list;
struct pl08x_txd *at;
spinlock_t lock;
struct pl08x_driver_data *host;
enum pl08x_dma_chan_state state;
bool slave;
struct pl08x_txd *waiting;
};
/**
* struct pl08x_platform_data - the platform configuration for the PL08x
* PrimeCells.
* @slave_channels: the channels defined for the different devices on the
* platform, all inclusive, including multiplexed channels. The available
* physical channels will be multiplexed around these signals as they are
* requested, just enumerate all possible channels.
* @get_signal: request a physical signal to be used for a DMA transfer
* immediately: if there is some multiplexing or similar blocking the use
* of the channel the transfer can be denied by returning less than zero,
* else it returns the allocated signal number
* @put_signal: indicate to the platform that this physical signal is not
* running any DMA transfer and multiplexing can be recycled
* @lli_buses: buses which LLIs can be fetched from: PL08X_AHB1 | PL08X_AHB2
* @mem_buses: buses which memory can be accessed from: PL08X_AHB1 | PL08X_AHB2
*/
struct pl08x_platform_data {
struct pl08x_channel_data *slave_channels;
unsigned int num_slave_channels;
struct pl08x_channel_data memcpy_channel;
int (*get_signal)(struct pl08x_dma_chan *);
void (*put_signal)(struct pl08x_dma_chan *);
u8 lli_buses;
u8 mem_buses;
};
#ifdef CONFIG_AMBA_PL08X
bool pl08x_filter_id(struct dma_chan *chan, void *chan_id);
#else
static inline bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
{
return false;
}
#endif
#endif /* AMBA_PL08X_H */