diff options
Diffstat (limited to 'drivers/media/rc/ir-sony-decoder.c')
| -rw-r--r-- | drivers/media/rc/ir-sony-decoder.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-sony-decoder.c b/drivers/media/rc/ir-sony-decoder.c new file mode 100644 index 00000000000..a92de80c48d --- /dev/null +++ b/drivers/media/rc/ir-sony-decoder.c @@ -0,0 +1,181 @@ +/* ir-sony-decoder.c - handle Sony IR Pulse/Space protocol + * + * Copyright (C) 2010 by David Härdeman <david@hardeman.nu> + * + * 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. + */ + +#include <linux/bitrev.h> +#include "rc-core-priv.h" + +#define SONY_UNIT 600000 /* ns */ +#define SONY_HEADER_PULSE (4 * SONY_UNIT) +#define SONY_HEADER_SPACE (1 * SONY_UNIT) +#define SONY_BIT_0_PULSE (1 * SONY_UNIT) +#define SONY_BIT_1_PULSE (2 * SONY_UNIT) +#define SONY_BIT_SPACE (1 * SONY_UNIT) +#define SONY_TRAILER_SPACE (10 * SONY_UNIT) /* minimum */ + +enum sony_state { + STATE_INACTIVE, + STATE_HEADER_SPACE, + STATE_BIT_PULSE, + STATE_BIT_SPACE, + STATE_FINISHED, +}; + +/** + * ir_sony_decode() - Decode one Sony pulse or space + * @dev: the struct rc_dev descriptor of the device + * @ev: the struct ir_raw_event descriptor of the pulse/space + * + * This function returns -EINVAL if the pulse violates the state machine + */ +static int ir_sony_decode(struct rc_dev *dev, struct ir_raw_event ev) +{ + struct sony_dec *data = &dev->raw->sony; + u32 scancode; + u8 device, subdevice, function; + + if (!(dev->raw->enabled_protocols & RC_TYPE_SONY)) + return 0; + + if (!is_timing_event(ev)) { + if (ev.reset) + data->state = STATE_INACTIVE; + return 0; + } + + if (!geq_margin(ev.duration, SONY_UNIT, SONY_UNIT / 2)) + goto out; + + IR_dprintk(2, "Sony 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, SONY_HEADER_PULSE, SONY_UNIT / 2)) + break; + + data->count = 0; + data->state = STATE_HEADER_SPACE; + return 0; + + case STATE_HEADER_SPACE: + if (ev.pulse) + break; + + if (!eq_margin(ev.duration, SONY_HEADER_SPACE, SONY_UNIT / 2)) + break; + + data->state = STATE_BIT_PULSE; + return 0; + + case STATE_BIT_PULSE: + if (!ev.pulse) + break; + + data->bits <<= 1; + if (eq_margin(ev.duration, SONY_BIT_1_PULSE, SONY_UNIT / 2)) + data->bits |= 1; + else if (!eq_margin(ev.duration, SONY_BIT_0_PULSE, SONY_UNIT / 2)) + break; + + data->count++; + data->state = STATE_BIT_SPACE; + return 0; + + case STATE_BIT_SPACE: + if (ev.pulse) + break; + + if (!geq_margin(ev.duration, SONY_BIT_SPACE, SONY_UNIT / 2)) + break; + + decrease_duration(&ev, SONY_BIT_SPACE); + + if (!geq_margin(ev.duration, SONY_UNIT, SONY_UNIT / 2)) { + data->state = STATE_BIT_PULSE; + return 0; + } + + data->state = STATE_FINISHED; + /* Fall through */ + + case STATE_FINISHED: + if (ev.pulse) + break; + + if (!geq_margin(ev.duration, SONY_TRAILER_SPACE, SONY_UNIT / 2)) + break; + + switch (data->count) { + case 12: + device = bitrev8((data->bits << 3) & 0xF8); + subdevice = 0; + function = bitrev8((data->bits >> 4) & 0xFE); + break; + case 15: + device = bitrev8((data->bits >> 0) & 0xFF); + subdevice = 0; + function = bitrev8((data->bits >> 7) & 0xFD); + break; + case 20: + device = bitrev8((data->bits >> 5) & 0xF8); + subdevice = bitrev8((data->bits >> 0) & 0xFF); + function = bitrev8((data->bits >> 12) & 0xFE); + break; + default: + IR_dprintk(1, "Sony invalid bitcount %u\n", data->count); + goto out; + } + + scancode = device << 16 | subdevice << 8 | function; + IR_dprintk(1, "Sony(%u) scancode 0x%05x\n", data->count, scancode); + rc_keydown(dev, scancode, 0); + data->state = STATE_INACTIVE; + return 0; + } + +out: + IR_dprintk(1, "Sony decode failed at state %d (%uus %s)\n", + data->state, TO_US(ev.duration), TO_STR(ev.pulse)); + data->state = STATE_INACTIVE; + return -EINVAL; +} + +static struct ir_raw_handler sony_handler = { + .protocols = RC_TYPE_SONY, + .decode = ir_sony_decode, +}; + +static int __init ir_sony_decode_init(void) +{ + ir_raw_handler_register(&sony_handler); + + printk(KERN_INFO "IR Sony protocol handler initialized\n"); + return 0; +} + +static void __exit ir_sony_decode_exit(void) +{ + ir_raw_handler_unregister(&sony_handler); +} + +module_init(ir_sony_decode_init); +module_exit(ir_sony_decode_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David Härdeman <david@hardeman.nu>"); +MODULE_DESCRIPTION("Sony IR protocol decoder"); |