diff options
Diffstat (limited to 'drivers/media/rc/ir-rcmm-decoder.c')
| -rw-r--r-- | drivers/media/rc/ir-rcmm-decoder.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/media/rc/ir-rcmm-decoder.c b/drivers/media/rc/ir-rcmm-decoder.c new file mode 100644 index 000000000..a8a34436f --- /dev/null +++ b/drivers/media/rc/ir-rcmm-decoder.c @@ -0,0 +1,255 @@ +// SPDX-License-Identifier: GPL-2.0+ +// ir-rcmm-decoder.c - A decoder for the RCMM IR protocol +// +// Copyright (C) 2018 by Patrick Lerda <patrick9876@free.fr> + +#include "rc-core-priv.h" +#include <linux/module.h> + +#define RCMM_UNIT 166 /* microseconds */ +#define RCMM_PREFIX_PULSE 417 /* 166.666666666666*2.5 */ +#define RCMM_PULSE_0 278 /* 166.666666666666*(1+2/3) */ +#define RCMM_PULSE_1 444 /* 166.666666666666*(2+2/3) */ +#define RCMM_PULSE_2 611 /* 166.666666666666*(3+2/3) */ +#define RCMM_PULSE_3 778 /* 166.666666666666*(4+2/3) */ + +enum rcmm_state { + STATE_INACTIVE, + STATE_LOW, + STATE_BUMP, + STATE_VALUE, + STATE_FINISHED, +}; + +static bool rcmm_mode(const struct rcmm_dec *data) +{ + return !((0x000c0000 & data->bits) == 0x000c0000); +} + +static int rcmm_miscmode(struct rc_dev *dev, struct rcmm_dec *data) +{ + switch (data->count) { + case 24: + if (dev->enabled_protocols & RC_PROTO_BIT_RCMM24) { + rc_keydown(dev, RC_PROTO_RCMM24, data->bits, 0); + data->state = STATE_INACTIVE; + return 0; + } + return -1; + + case 12: + if (dev->enabled_protocols & RC_PROTO_BIT_RCMM12) { + rc_keydown(dev, RC_PROTO_RCMM12, data->bits, 0); + data->state = STATE_INACTIVE; + return 0; + } + return -1; + } + + return -1; +} + +/** + * ir_rcmm_decode() - Decode one RCMM 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_rcmm_decode(struct rc_dev *dev, struct ir_raw_event ev) +{ + struct rcmm_dec *data = &dev->raw->rcmm; + u32 scancode; + u8 toggle; + int value; + + if (!(dev->enabled_protocols & (RC_PROTO_BIT_RCMM32 | + RC_PROTO_BIT_RCMM24 | + RC_PROTO_BIT_RCMM12))) + return 0; + + if (!is_timing_event(ev)) { + if (ev.overflow) + data->state = STATE_INACTIVE; + return 0; + } + + switch (data->state) { + case STATE_INACTIVE: + if (!ev.pulse) + break; + + if (!eq_margin(ev.duration, RCMM_PREFIX_PULSE, RCMM_UNIT)) + break; + + data->state = STATE_LOW; + data->count = 0; + data->bits = 0; + return 0; + + case STATE_LOW: + if (ev.pulse) + break; + + if (!eq_margin(ev.duration, RCMM_PULSE_0, RCMM_UNIT)) + break; + + data->state = STATE_BUMP; + return 0; + + case STATE_BUMP: + if (!ev.pulse) + break; + + if (!eq_margin(ev.duration, RCMM_UNIT, RCMM_UNIT / 2)) + break; + + data->state = STATE_VALUE; + return 0; + + case STATE_VALUE: + if (ev.pulse) + break; + + if (eq_margin(ev.duration, RCMM_PULSE_0, RCMM_UNIT / 2)) + value = 0; + else if (eq_margin(ev.duration, RCMM_PULSE_1, RCMM_UNIT / 2)) + value = 1; + else if (eq_margin(ev.duration, RCMM_PULSE_2, RCMM_UNIT / 2)) + value = 2; + else if (eq_margin(ev.duration, RCMM_PULSE_3, RCMM_UNIT / 2)) + value = 3; + else + value = -1; + + if (value == -1) { + if (!rcmm_miscmode(dev, data)) + return 0; + break; + } + + data->bits <<= 2; + data->bits |= value; + + data->count += 2; + + if (data->count < 32) + data->state = STATE_BUMP; + else + data->state = STATE_FINISHED; + + return 0; + + case STATE_FINISHED: + if (!ev.pulse) + break; + + if (!eq_margin(ev.duration, RCMM_UNIT, RCMM_UNIT / 2)) + break; + + if (rcmm_mode(data)) { + toggle = !!(0x8000 & data->bits); + scancode = data->bits & ~0x8000; + } else { + toggle = 0; + scancode = data->bits; + } + + if (dev->enabled_protocols & RC_PROTO_BIT_RCMM32) { + rc_keydown(dev, RC_PROTO_RCMM32, scancode, toggle); + data->state = STATE_INACTIVE; + return 0; + } + + break; + } + + dev_dbg(&dev->dev, "RC-MM decode failed at count %d state %d (%uus %s)\n", + data->count, data->state, ev.duration, TO_STR(ev.pulse)); + data->state = STATE_INACTIVE; + return -EINVAL; +} + +static const int rcmmspace[] = { + RCMM_PULSE_0, + RCMM_PULSE_1, + RCMM_PULSE_2, + RCMM_PULSE_3, +}; + +static int ir_rcmm_rawencoder(struct ir_raw_event **ev, unsigned int max, + unsigned int n, u32 data) +{ + int i; + int ret; + + ret = ir_raw_gen_pulse_space(ev, &max, RCMM_PREFIX_PULSE, RCMM_PULSE_0); + if (ret) + return ret; + + for (i = n - 2; i >= 0; i -= 2) { + const unsigned int space = rcmmspace[(data >> i) & 3]; + + ret = ir_raw_gen_pulse_space(ev, &max, RCMM_UNIT, space); + if (ret) + return ret; + } + + return ir_raw_gen_pulse_space(ev, &max, RCMM_UNIT, RCMM_PULSE_3 * 2); +} + +static int ir_rcmm_encode(enum rc_proto protocol, u32 scancode, + struct ir_raw_event *events, unsigned int max) +{ + struct ir_raw_event *e = events; + int ret; + + switch (protocol) { + case RC_PROTO_RCMM32: + ret = ir_rcmm_rawencoder(&e, max, 32, scancode); + break; + case RC_PROTO_RCMM24: + ret = ir_rcmm_rawencoder(&e, max, 24, scancode); + break; + case RC_PROTO_RCMM12: + ret = ir_rcmm_rawencoder(&e, max, 12, scancode); + break; + default: + ret = -EINVAL; + } + + if (ret < 0) + return ret; + + return e - events; +} + +static struct ir_raw_handler rcmm_handler = { + .protocols = RC_PROTO_BIT_RCMM32 | + RC_PROTO_BIT_RCMM24 | + RC_PROTO_BIT_RCMM12, + .decode = ir_rcmm_decode, + .encode = ir_rcmm_encode, + .carrier = 36000, + .min_timeout = RCMM_PULSE_3 + RCMM_UNIT, +}; + +static int __init ir_rcmm_decode_init(void) +{ + ir_raw_handler_register(&rcmm_handler); + + pr_info("IR RCMM protocol handler initialized\n"); + return 0; +} + +static void __exit ir_rcmm_decode_exit(void) +{ + ir_raw_handler_unregister(&rcmm_handler); +} + +module_init(ir_rcmm_decode_init); +module_exit(ir_rcmm_decode_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick Lerda"); +MODULE_DESCRIPTION("RCMM IR protocol decoder"); |