| 1 | /* |
| 2 | * arch/ubicom32/include/asm/ubicom32ring.h |
| 3 | * Userspace I/O platform driver for Ubicom32 ring buffers |
| 4 | * |
| 5 | * (C) Copyright 2009, Ubicom, Inc. |
| 6 | * |
| 7 | * This file is part of the Ubicom32 Linux Kernel Port. |
| 8 | * |
| 9 | * The Ubicom32 Linux Kernel Port is free software: you can redistribute |
| 10 | * it and/or modify it under the terms of the GNU General Public License |
| 11 | * as published by the Free Software Foundation, either version 2 of the |
| 12 | * License, or (at your option) any later version. |
| 13 | * |
| 14 | * The Ubicom32 Linux Kernel Port is distributed in the hope that it |
| 15 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 16 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| 17 | * the GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with the Ubicom32 Linux Kernel Port. If not, |
| 21 | * see <http://www.gnu.org/licenses/>. |
| 22 | */ |
| 23 | |
| 24 | #ifndef _ASM_UBICOM32_UBICOM32RING_H |
| 25 | #define _ASM_UBICOM32_UBICOM32RING_H |
| 26 | |
| 27 | #define UIO_UBICOM32RING_REG_VERSION 2 |
| 28 | |
| 29 | struct uio_ubicom32ring_desc { |
| 30 | volatile unsigned int head; |
| 31 | volatile unsigned int tail; |
| 32 | unsigned int entries; |
| 33 | volatile unsigned int ring[0]; |
| 34 | }; |
| 35 | |
| 36 | struct uio_ubicom32ring_regs { |
| 37 | unsigned int version; |
| 38 | |
| 39 | /* |
| 40 | * Magic type used to identify the ring set. Each driver will |
| 41 | * have a different magic value. |
| 42 | */ |
| 43 | unsigned int magic; |
| 44 | |
| 45 | /* |
| 46 | * Registers defined by the driver |
| 47 | */ |
| 48 | unsigned int regs_size; |
| 49 | void *regs; |
| 50 | |
| 51 | /* |
| 52 | * The locations of the rings |
| 53 | * |
| 54 | * DO NOT ADD ANYTHING BELOW THIS LINE |
| 55 | */ |
| 56 | unsigned int num_rings; |
| 57 | struct uio_ubicom32ring_desc *rings[0]; |
| 58 | }; |
| 59 | |
| 60 | /* |
| 61 | * ringtio_ring_flush |
| 62 | */ |
| 63 | static inline void ringtio_ring_flush(struct uio_ubicom32ring_desc *rd) |
| 64 | { |
| 65 | rd->head = rd->tail = 0; |
| 66 | } |
| 67 | |
| 68 | /* |
| 69 | * ringtio_ring_get |
| 70 | */ |
| 71 | static inline int ringtio_ring_get(struct uio_ubicom32ring_desc *rd, void **val) |
| 72 | { |
| 73 | if (rd->head == rd->tail) { |
| 74 | return 0; |
| 75 | } |
| 76 | |
| 77 | *val = (void *)rd->ring[rd->head++]; |
| 78 | if (rd->head == rd->entries) { |
| 79 | rd->head = 0; |
| 80 | } |
| 81 | return 1; |
| 82 | } |
| 83 | |
| 84 | /* |
| 85 | * ringtio_ring_put |
| 86 | */ |
| 87 | static inline int ringtio_ring_put(struct uio_ubicom32ring_desc *rd, void *val) |
| 88 | { |
| 89 | unsigned int newtail = rd->tail + 1; |
| 90 | if (newtail == rd->entries) { |
| 91 | newtail = 0; |
| 92 | } |
| 93 | |
| 94 | if (newtail == rd->head) { |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | rd->ring[rd->tail] = (unsigned int)val; |
| 99 | rd->tail = newtail; |
| 100 | return 1; |
| 101 | } |
| 102 | |
| 103 | #endif /* _ASM_UBICOM32_UBICOM32RING_H */ |
| 104 | |
