dbdma.h (5459B) - Raw
1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2008 Nathan Whitehorn 5 * All rights reserved 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #ifndef _MACHINE_DBDMA_H_ 30 #define _MACHINE_DBDMA_H_ 31 32 #include <sys/param.h> 33 #include <machine/bus.h> 34 35 /* 36 * Apple's DBDMA (Descriptor-based DMA) interface is a common DMA engine 37 * used by a variety of custom Apple ASICs. It is described in the CHRP 38 * specification and in the book Macintosh Technology in the Common 39 * Hardware Reference Platform, copyright 1995 Apple Computer. 40 */ 41 42 /* DBDMA Command Values */ 43 44 enum { 45 DBDMA_OUTPUT_MORE = 0, 46 DBDMA_OUTPUT_LAST = 1, 47 DBDMA_INPUT_MORE = 2, 48 DBDMA_INPUT_LAST = 3, 49 50 DBDMA_STORE_QUAD = 4, 51 DBDMA_LOAD_QUAD = 5, 52 DBDMA_NOP = 6, 53 DBDMA_STOP = 7 54 }; 55 56 /* These codes are for the interrupt, branch, and wait flags */ 57 58 enum { 59 DBDMA_NEVER = 0, 60 DBDMA_COND_TRUE = 1, 61 DBDMA_COND_FALSE = 2, 62 DBDMA_ALWAYS = 3 63 }; 64 65 /* Channel status bits */ 66 #define DBDMA_STATUS_RUN (0x01 << 15) 67 #define DBDMA_STATUS_PAUSE (0x01 << 14) 68 #define DBDMA_STATUS_FLUSH (0x01 << 13) 69 #define DBDMA_STATUS_WAKE (0x01 << 12) 70 #define DBDMA_STATUS_DEAD (0x01 << 11) 71 #define DBDMA_STATUS_ACTIVE (0x01 << 10) 72 73 /* Set by hardware if a branch was taken */ 74 #define DBDMA_STATUS_BRANCH 8 75 76 struct dbdma_command; 77 typedef struct dbdma_command dbdma_command_t; 78 struct dbdma_channel; 79 typedef struct dbdma_channel dbdma_channel_t; 80 81 int dbdma_allocate_channel(struct resource *dbdma_regs, u_int offset, 82 bus_dma_tag_t parent_dma, int slots, dbdma_channel_t **chan); 83 84 int dbdma_resize_channel(dbdma_channel_t *chan, int newslots); 85 int dbdma_free_channel(dbdma_channel_t *chan); 86 87 void dbdma_run(dbdma_channel_t *chan); 88 void dbdma_stop(dbdma_channel_t *chan); 89 void dbdma_reset(dbdma_channel_t *chan); 90 void dbdma_set_current_cmd(dbdma_channel_t *chan, int slot); 91 92 void dbdma_pause(dbdma_channel_t *chan); 93 void dbdma_wake(dbdma_channel_t *chan); 94 95 /* 96 * DBDMA uses a 16 bit channel control register to describe the current 97 * state of DMA on the channel. The high-order bits (8-15) contain information 98 * on the run state and are listed in the DBDMA_STATUS_* constants above. These 99 * are manipulated with the dbdma_run/stop/reset() routines above. 100 * 101 * The low order bits (0-7) are device dependent status bits. These can be set 102 * and read by both hardware and software. The mask is the set of bits to 103 * modify; if mask is 0x03 and value is 0, the lowest order 2 bits will be 104 * zeroed. 105 */ 106 107 uint16_t dbdma_get_chan_status(dbdma_channel_t *chan); 108 109 uint8_t dbdma_get_device_status(dbdma_channel_t *chan); 110 void dbdma_set_device_status(dbdma_channel_t *chan, uint8_t mask, 111 uint8_t value); 112 113 /* 114 * Each DBDMA command word has the current channel status register and the 115 * number of residual bytes (requested - actually transferred) written to it 116 * at time of command completion. 117 */ 118 119 uint16_t dbdma_get_cmd_status(dbdma_channel_t *chan, int slot); 120 uint16_t dbdma_get_residuals(dbdma_channel_t *chan, int slot); 121 122 void dbdma_clear_cmd_status(dbdma_channel_t *chan, int slot); 123 124 /* 125 * The interrupt/branch/wait selector let you specify a set of values 126 * of the device dependent status bits that will cause intterupt/branch/wait 127 * conditions to be taken if the flags for these are set to one of the 128 * DBDMA_COND_* values. 129 * 130 * The condition is considered true if (status & mask) == value. 131 */ 132 133 void dbdma_set_interrupt_selector(dbdma_channel_t *chan, uint8_t mask, 134 uint8_t value); 135 void dbdma_set_branch_selector(dbdma_channel_t *chan, uint8_t mask, 136 uint8_t value); 137 void dbdma_set_wait_selector(dbdma_channel_t *chan, uint8_t mask, 138 uint8_t value); 139 140 void dbdma_insert_command(dbdma_channel_t *chan, int slot, int command, 141 int stream, bus_addr_t data, size_t count, uint8_t interrupt, 142 uint8_t branch, uint8_t wait, uint32_t branch_slot); 143 144 void dbdma_insert_stop(dbdma_channel_t *chan, int slot); 145 void dbdma_insert_nop(dbdma_channel_t *chan, int slot); 146 void dbdma_insert_branch(dbdma_channel_t *chan, int slot, int to_slot); 147 148 void dbdma_sync_commands(dbdma_channel_t *chan, bus_dmasync_op_t op); 149 150 void dbdma_save_state(dbdma_channel_t *chan); 151 void dbdma_restore_state(dbdma_channel_t *chan); 152 153 #endif /* _MACHINE_DBDMA_H_ */