include/linux/amba/pl08x.h

   1 /*
   2  * linux/amba/pl08x.h - ARM PrimeCell DMA Controller driver
   3  *
   4  * Copyright (C) 2005 ARM Ltd
   5  * Copyright (C) 2010 ST-Ericsson SA
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * pl08x information required by platform code
  12  *
  13  * Please credit ARM.com
  14  * Documentation: ARM DDI 0196D
  15  */
  16
  17 #ifndef AMBA_PL08X_H
  18 #define AMBA_PL08X_H
  19
  20 /* We need sizes of structs from this header */
  21 #include <linux/dmaengine.h>
  22 #include <linux/interrupt.h>
  23
  24 struct pl08x_lli;
  25 struct pl08x_driver_data;
  26
  27 /* Bitmasks for selecting AHB ports for DMA transfers */
  28 enum {
  29         PL08X_AHB1 = (1 << 0),
  30         PL08X_AHB2 = (1 << 1)
  31 };
  32
  33 /**
  34  * struct pl08x_channel_data - data structure to pass info between
  35  * platform and PL08x driver regarding channel configuration
  36  * @bus_id: name of this device channel, not just a device name since
  37  * devices may have more than one channel e.g. "foo_tx"
  38  * @min_signal: the minimum DMA signal number to be muxed in for this
  39  * channel (for platforms supporting muxed signals). If you have
  40  * static assignments, make sure this is set to the assigned signal
  41  * number, PL08x have 16 possible signals in number 0 thru 15 so
  42  * when these are not enough they often get muxed (in hardware)
  43  * disabling simultaneous use of the same channel for two devices.
  44  * @max_signal: the maximum DMA signal number to be muxed in for
  45  * the channel. Set to the same as min_signal for
  46  * devices with static assignments
  47  * @muxval: a number usually used to poke into some mux regiser to
  48  * mux in the signal to this channel
  49  * @cctl_opt: default options for the channel control register
  50  * @device_fc: Flow Controller Settings for ccfg register. Only valid for slave
  51  * channels. Fill with 'true' if peripheral should be flow controller. Direction
  52  * will be selected at Runtime.
  53  * @addr: source/target address in physical memory for this DMA channel,
  54  * can be the address of a FIFO register for burst requests for example.
  55  * This can be left undefined if the PrimeCell API is used for configuring
  56  * this.
  57  * @circular_buffer: whether the buffer passed in is circular and
  58  * shall simply be looped round round (like a record baby round
  59  * round round round)
  60  * @single: the device connected to this channel will request single DMA
  61  * transfers, not bursts. (Bursts are default.)
  62  * @periph_buses: the device connected to this channel is accessible via
  63  * these buses (use PL08X_AHB1 | PL08X_AHB2).
  64  */
  65 struct pl08x_channel_data {
  66         char *bus_id;
  67         int min_signal;
  68         int max_signal;
  69         u32 muxval;
  70         u32 cctl;
  71         bool device_fc;
  72         dma_addr_t addr;
  73         bool circular_buffer;
  74         bool single;
  75         u8 periph_buses;
  76 };
  77
  78 /**
  79  * Struct pl08x_bus_data - information of source or destination
  80  * busses for a transfer
  81  * @addr: current address
  82  * @maxwidth: the maximum width of a transfer on this bus
  83  * @buswidth: the width of this bus in bytes: 1, 2 or 4
  84  */
  85 struct pl08x_bus_data {
  86         dma_addr_t addr;
  87         u8 maxwidth;
  88         u8 buswidth;
  89 };
  90
  91 /**
  92  * struct pl08x_phy_chan - holder for the physical channels
  93  * @id: physical index to this channel
  94  * @lock: a lock to use when altering an instance of this struct
  95  * @signal: the physical signal (aka channel) serving this physical channel
  96  * right now
  97  * @serving: the virtual channel currently being served by this physical
  98  * channel
  99  */
 100 struct pl08x_phy_chan {
 101         unsigned int id;
 102         void __iomem *base;
 103         spinlock_t lock;
 104         int signal;
 105         struct pl08x_dma_chan *serving;
 106 };
 107
 108 /**
 109  * struct pl08x_txd - wrapper for struct dma_async_tx_descriptor
 110  * @tx: async tx descriptor
 111  * @node: node for txd list for channels
 112  * @src_addr: src address of txd
 113  * @dst_addr: dst address of txd
 114  * @len: transfer len in bytes
 115  * @direction: direction of transfer
 116  * @llis_bus: DMA memory address (physical) start for the LLIs
 117  * @llis_va: virtual memory address start for the LLIs
 118  * @cctl: control reg values for current txd
 119  * @ccfg: config reg values for current txd
 120  */
 121 struct pl08x_txd {
 122         struct dma_async_tx_descriptor tx;
 123         struct list_head node;
 124         enum dma_data_direction direction;
 125         dma_addr_t src_addr;
 126         dma_addr_t dst_addr;
 127         size_t len;
 128         dma_addr_t llis_bus;
 129         struct pl08x_lli *llis_va;
 130         /* Default cctl value for LLIs */
 131         u32 cctl;
 132         /*
 133          * Settings to be put into the physical channel when we
 134          * trigger this txd.  Other registers are in llis_va[0].
 135          */
 136         u32 ccfg;
 137 };
 138
 139 /**
 140  * struct pl08x_dma_chan_state - holds the PL08x specific virtual channel
 141  * states
 142  * @PL08X_CHAN_IDLE: the channel is idle
 143  * @PL08X_CHAN_RUNNING: the channel has allocated a physical transport
 144  * channel and is running a transfer on it
 145  * @PL08X_CHAN_PAUSED: the channel has allocated a physical transport
 146  * channel, but the transfer is currently paused
 147  * @PL08X_CHAN_WAITING: the channel is waiting for a physical transport
 148  * channel to become available (only pertains to memcpy channels)
 149  */
 150 enum pl08x_dma_chan_state {
 151         PL08X_CHAN_IDLE,
 152         PL08X_CHAN_RUNNING,
 153         PL08X_CHAN_PAUSED,
 154         PL08X_CHAN_WAITING,
 155 };
 156
 157 /**
 158  * struct pl08x_dma_chan - this structure wraps a DMA ENGINE channel
 159  * @chan: wrappped abstract channel
 160  * @phychan: the physical channel utilized by this channel, if there is one
 161  * @phychan_hold: if non-zero, hold on to the physical channel even if we
 162  * have no pending entries
 163  * @tasklet: tasklet scheduled by the IRQ to handle actual work etc
 164  * @name: name of channel
 165  * @cd: channel platform data
 166  * @runtime_addr: address for RX/TX according to the runtime config
 167  * @runtime_direction: current direction of this channel according to
 168  * runtime config
 169  * @lc: last completed transaction on this channel
 170  * @pend_list: queued transactions pending on this channel
 171  * @at: active transaction on this channel
 172  * @lock: a lock for this channel data
 173  * @host: a pointer to the host (internal use)
 174  * @state: whether the channel is idle, paused, running etc
 175  * @slave: whether this channel is a device (slave) or for memcpy
 176  * @waiting: a TX descriptor on this channel which is waiting for a physical
 177  * channel to become available
 178  */
 179 struct pl08x_dma_chan {
 180         struct dma_chan chan;
 181         struct pl08x_phy_chan *phychan;
 182         int phychan_hold;
 183         struct tasklet_struct tasklet;
 184         char *name;
 185         const struct pl08x_channel_data *cd;
 186         dma_addr_t src_addr;
 187         dma_addr_t dst_addr;
 188         u32 src_cctl;
 189         u32 dst_cctl;
 190         enum dma_data_direction runtime_direction;
 191         dma_cookie_t lc;
 192         struct list_head pend_list;
 193         struct pl08x_txd *at;
 194         spinlock_t lock;
 195         struct pl08x_driver_data *host;
 196         enum pl08x_dma_chan_state state;
 197         bool slave;
 198         struct pl08x_txd *waiting;
 199 };
 200
 201 /**
 202  * struct pl08x_platform_data - the platform configuration for the PL08x
 203  * PrimeCells.
 204  * @slave_channels: the channels defined for the different devices on the
 205  * platform, all inclusive, including multiplexed channels. The available
 206  * physical channels will be multiplexed around these signals as they are
 207  * requested, just enumerate all possible channels.
 208  * @get_signal: request a physical signal to be used for a DMA transfer
 209  * immediately: if there is some multiplexing or similar blocking the use
 210  * of the channel the transfer can be denied by returning less than zero,
 211  * else it returns the allocated signal number
 212  * @put_signal: indicate to the platform that this physical signal is not
 213  * running any DMA transfer and multiplexing can be recycled
 214  * @lli_buses: buses which LLIs can be fetched from: PL08X_AHB1 | PL08X_AHB2
 215  * @mem_buses: buses which memory can be accessed from: PL08X_AHB1 | PL08X_AHB2
 216  */
 217 struct pl08x_platform_data {
 218         const struct pl08x_channel_data *slave_channels;
 219         unsigned int num_slave_channels;
 220         struct pl08x_channel_data memcpy_channel;
 221         int (*get_signal)(struct pl08x_dma_chan *);
 222         void (*put_signal)(struct pl08x_dma_chan *);
 223         u8 lli_buses;
 224         u8 mem_buses;
 225 };
 226
 227 #ifdef CONFIG_AMBA_PL08X
 228 bool pl08x_filter_id(struct dma_chan *chan, void *chan_id);
 229 #else
 230 static inline bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
 231 {
 232         return false;
 233 }
 234 #endif
 235
 236 #endif  /* AMBA_PL08X_H */