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Diffstat (limited to 'include/linux/amba')
| -rw-r--r-- | include/linux/amba/pl08x.h | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/include/linux/amba/pl08x.h b/include/linux/amba/pl08x.h new file mode 100644 index 00000000000..521a0f8974a --- /dev/null +++ b/include/linux/amba/pl08x.h @@ -0,0 +1,222 @@ +/* + * 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_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.) + */ +struct pl08x_channel_data { + char *bus_id; + int min_signal; + int max_signal; + u32 muxval; + u32 cctl; + u32 ccfg; + dma_addr_t addr; + bool circular_buffer; + bool single; +}; + +/** + * 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; + u32 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; + u32 csrc; + u32 cdst; + u32 clli; + u32 cctl; + u32 ccfg; +}; + +/** + * 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; + struct pl08x_bus_data srcbus; + struct pl08x_bus_data dstbus; + int len; + dma_addr_t llis_bus; + void *llis_va; + struct pl08x_channel_data *cd; + bool active; + /* + * Settings to be put into the physical channel when we + * trigger this txd + */ + u32 csrc; + u32 cdst; + u32 clli; + u32 cctl; +}; + +/** + * 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 + * @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 + * @desc_list: queued transactions pending on this channel + * @at: active transaction on this channel + * @lockflags: sometimes we let a lock last between two function calls, + * especially prep/submit, and then we need to store the IRQ flags + * in the channel state, here + * @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; + struct tasklet_struct tasklet; + char *name; + struct pl08x_channel_data *cd; + dma_addr_t runtime_addr; + enum dma_data_direction runtime_direction; + atomic_t last_issued; + dma_cookie_t lc; + struct list_head desc_list; + struct pl08x_txd *at; + unsigned long lockflags; + spinlock_t lock; + void *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 + * @bus_bit_lli: Bit[0] of the address indicated which AHB bus master the + * LLI addresses are on 0/1 Master 1/2. + */ +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 *); +}; + +#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 */ |