diff options
Diffstat (limited to 'drivers/media/rc/ir-sanyo-decoder.c')
| -rw-r--r-- | drivers/media/rc/ir-sanyo-decoder.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-sanyo-decoder.c b/drivers/media/rc/ir-sanyo-decoder.c new file mode 100644 index 00000000000..d38fbdd0b25 --- /dev/null +++ b/drivers/media/rc/ir-sanyo-decoder.c @@ -0,0 +1,205 @@ +/* ir-sanyo-decoder.c - handle SANYO IR Pulse/Space protocol + * + * Copyright (C) 2011 by Mauro Carvalho Chehab <mchehab@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * This protocol uses the NEC protocol timings. However, data is formatted as: + * 13 bits Custom Code + * 13 bits NOT(Custom Code) + * 8 bits Key data + * 8 bits NOT(Key data) + * + * According with LIRC, this protocol is used on Sanyo, Aiwa and Chinon + * Information for this protocol is available at the Sanyo LC7461 datasheet. + */ + +#include <linux/module.h> +#include <linux/bitrev.h> +#include "rc-core-priv.h" + +#define SANYO_NBITS (13+13+8+8) +#define SANYO_UNIT 562500 /* ns */ +#define SANYO_HEADER_PULSE (16 * SANYO_UNIT) +#define SANYO_HEADER_SPACE (8 * SANYO_UNIT) +#define SANYO_BIT_PULSE (1 * SANYO_UNIT) +#define SANYO_BIT_0_SPACE (1 * SANYO_UNIT) +#define SANYO_BIT_1_SPACE (3 * SANYO_UNIT) +#define SANYO_REPEAT_SPACE (150 * SANYO_UNIT) +#define SANYO_TRAILER_PULSE (1 * SANYO_UNIT) +#define SANYO_TRAILER_SPACE (10 * SANYO_UNIT) /* in fact, 42 */ + +enum sanyo_state { + STATE_INACTIVE, + STATE_HEADER_SPACE, + STATE_BIT_PULSE, + STATE_BIT_SPACE, + STATE_TRAILER_PULSE, + STATE_TRAILER_SPACE, +}; + +/** + * ir_sanyo_decode() - Decode one SANYO pulse or space + * @dev: the struct rc_dev descriptor of the device + * @duration: the struct ir_raw_event descriptor of the pulse/space + * + * This function returns -EINVAL if the pulse violates the state machine + */ +static int ir_sanyo_decode(struct rc_dev *dev, struct ir_raw_event ev) +{ + struct sanyo_dec *data = &dev->raw->sanyo; + u32 scancode; + u8 address, not_address, command, not_command; + + if (!(dev->raw->enabled_protocols & RC_TYPE_SANYO)) + return 0; + + if (!is_timing_event(ev)) { + if (ev.reset) { + IR_dprintk(1, "SANYO event reset received. reset to state 0\n"); + data->state = STATE_INACTIVE; + } + return 0; + } + + IR_dprintk(2, "SANYO decode started at state %d (%uus %s)\n", + data->state, TO_US(ev.duration), TO_STR(ev.pulse)); + + switch (data->state) { + + case STATE_INACTIVE: + if (!ev.pulse) + break; + + if (eq_margin(ev.duration, SANYO_HEADER_PULSE, SANYO_UNIT / 2)) { + data->count = 0; + data->state = STATE_HEADER_SPACE; + return 0; + } + break; + + + case STATE_HEADER_SPACE: + if (ev.pulse) + break; + + if (eq_margin(ev.duration, SANYO_HEADER_SPACE, SANYO_UNIT / 2)) { + data->state = STATE_BIT_PULSE; + return 0; + } + + break; + + case STATE_BIT_PULSE: + if (!ev.pulse) + break; + + if (!eq_margin(ev.duration, SANYO_BIT_PULSE, SANYO_UNIT / 2)) + break; + + data->state = STATE_BIT_SPACE; + return 0; + + case STATE_BIT_SPACE: + if (ev.pulse) + break; + + if (!data->count && geq_margin(ev.duration, SANYO_REPEAT_SPACE, SANYO_UNIT / 2)) { + if (!dev->keypressed) { + IR_dprintk(1, "SANYO discarding last key repeat: event after key up\n"); + } else { + rc_repeat(dev); + IR_dprintk(1, "SANYO repeat last key\n"); + data->state = STATE_INACTIVE; + } + return 0; + } + + data->bits <<= 1; + if (eq_margin(ev.duration, SANYO_BIT_1_SPACE, SANYO_UNIT / 2)) + data->bits |= 1; + else if (!eq_margin(ev.duration, SANYO_BIT_0_SPACE, SANYO_UNIT / 2)) + break; + data->count++; + + if (data->count == SANYO_NBITS) + data->state = STATE_TRAILER_PULSE; + else + data->state = STATE_BIT_PULSE; + + return 0; + + case STATE_TRAILER_PULSE: + if (!ev.pulse) + break; + + if (!eq_margin(ev.duration, SANYO_TRAILER_PULSE, SANYO_UNIT / 2)) + break; + + data->state = STATE_TRAILER_SPACE; + return 0; + + case STATE_TRAILER_SPACE: + if (ev.pulse) + break; + + if (!geq_margin(ev.duration, SANYO_TRAILER_SPACE, SANYO_UNIT / 2)) + break; + + address = bitrev16((data->bits >> 29) & 0x1fff) >> 3; + not_address = bitrev16((data->bits >> 16) & 0x1fff) >> 3; + command = bitrev8((data->bits >> 8) & 0xff); + not_command = bitrev8((data->bits >> 0) & 0xff); + + if ((command ^ not_command) != 0xff) { + IR_dprintk(1, "SANYO checksum error: received 0x%08Lx\n", + data->bits); + data->state = STATE_INACTIVE; + return 0; + } + + scancode = address << 8 | command; + IR_dprintk(1, "SANYO scancode: 0x%06x\n", scancode); + rc_keydown(dev, scancode, 0); + data->state = STATE_INACTIVE; + return 0; + } + + IR_dprintk(1, "SANYO decode failed at count %d state %d (%uus %s)\n", + data->count, data->state, TO_US(ev.duration), TO_STR(ev.pulse)); + data->state = STATE_INACTIVE; + return -EINVAL; +} + +static struct ir_raw_handler sanyo_handler = { + .protocols = RC_TYPE_SANYO, + .decode = ir_sanyo_decode, +}; + +static int __init ir_sanyo_decode_init(void) +{ + ir_raw_handler_register(&sanyo_handler); + + printk(KERN_INFO "IR SANYO protocol handler initialized\n"); + return 0; +} + +static void __exit ir_sanyo_decode_exit(void) +{ + ir_raw_handler_unregister(&sanyo_handler); +} + +module_init(ir_sanyo_decode_init); +module_exit(ir_sanyo_decode_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>"); +MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)"); +MODULE_DESCRIPTION("SANYO IR protocol decoder"); |