diff options
Diffstat (limited to 'drivers/media/IR/ir-rc5-decoder.c')
-rw-r--r-- | drivers/media/IR/ir-rc5-decoder.c | 150 |
1 files changed, 75 insertions, 75 deletions
diff --git a/drivers/media/IR/ir-rc5-decoder.c b/drivers/media/IR/ir-rc5-decoder.c index 6323066438b..1d0857b6908 100644 --- a/drivers/media/IR/ir-rc5-decoder.c +++ b/drivers/media/IR/ir-rc5-decoder.c @@ -21,11 +21,8 @@ #include <media/ir-core.h> -static unsigned int ir_rc5_remote_gap = 888888; - #define RC5_NBITS 14 -#define RC5_BIT (ir_rc5_remote_gap * 2) -#define RC5_DURATION (ir_rc5_remote_gap * RC5_NBITS) +#define RC5_UNIT 888888 /* ns */ /* Used to register rc5_decoder clients */ static LIST_HEAD(decoder_list); @@ -33,13 +30,9 @@ static DEFINE_SPINLOCK(decoder_lock); enum rc5_state { STATE_INACTIVE, - STATE_MARKSPACE, - STATE_TRAILER, -}; - -struct rc5_code { - u8 address; - u8 command; + STATE_BIT_START, + STATE_BIT_END, + STATE_FINISHED, }; struct decoder_data { @@ -49,8 +42,9 @@ struct decoder_data { /* State machine control */ enum rc5_state state; - struct rc5_code rc5_code; - unsigned code, elapsed, last_bit, last_code; + u32 rc5_bits; + int last_unit; + unsigned count; }; @@ -122,18 +116,19 @@ static struct attribute_group decoder_attribute_group = { }; /** - * handle_event() - Decode one RC-5 pulse or space + * ir_rc5_decode() - Decode one RC-5 pulse or space * @input_dev: the struct input_dev descriptor of the device - * @ev: event array with type/duration of pulse/space + * @duration: duration of pulse/space in ns * * This function returns -EINVAL if the pulse violates the state machine */ -static int ir_rc5_decode(struct input_dev *input_dev, - struct ir_raw_event *ev) +static int ir_rc5_decode(struct input_dev *input_dev, s64 duration) { struct decoder_data *data; struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); - int is_pulse, scancode, delta, toggle; + u8 command, system, toggle; + u32 scancode; + int u; data = get_decoder_data(ir_dev); if (!data) @@ -142,79 +137,84 @@ static int ir_rc5_decode(struct input_dev *input_dev, if (!data->enabled) return 0; - delta = DIV_ROUND_CLOSEST(ev->delta.tv_nsec, ir_rc5_remote_gap); - - /* The duration time refers to the last bit time */ - is_pulse = (ev->type & IR_PULSE) ? 1 : 0; - - /* Very long delays are considered as start events */ - if (delta > RC5_DURATION || (ev->type & IR_START_EVENT)) + if (IS_RESET(duration)) { data->state = STATE_INACTIVE; - - switch (data->state) { - case STATE_INACTIVE: - IR_dprintk(2, "currently inative. Start bit (%s) @%uus\n", - is_pulse ? "pulse" : "space", - (unsigned)(ev->delta.tv_nsec + 500) / 1000); - - /* Discards the initial start space */ - if (!is_pulse) - goto err; - data->code = 1; - data->last_bit = 1; - data->elapsed = 0; - memset(&data->rc5_code, 0, sizeof(data->rc5_code)); - data->state = STATE_MARKSPACE; return 0; - case STATE_MARKSPACE: - if (delta != 1) - data->last_bit = data->last_bit ? 0 : 1; + } - data->elapsed += delta; + u = TO_UNITS(duration, RC5_UNIT); + if (DURATION(u) == 0) + goto out; - if ((data->elapsed % 2) == 1) - return 0; +again: + IR_dprintk(2, "RC5 decode started at state %i (%i units, %ius)\n", + data->state, u, TO_US(duration)); - data->code <<= 1; - data->code |= data->last_bit; - - /* Fill the 2 unused bits at the command with 0 */ - if (data->elapsed / 2 == 6) - data->code <<= 2; + if (DURATION(u) == 0 && data->state != STATE_FINISHED) + return 0; - if (data->elapsed >= (RC5_NBITS - 1) * 2) { - scancode = data->code; + switch (data->state) { - /* Check for the start bits */ - if ((scancode & 0xc000) != 0xc000) { - IR_dprintk(1, "Code 0x%04x doesn't have two start bits. It is not RC-5\n", scancode); - goto err; + case STATE_INACTIVE: + if (IS_PULSE(u)) { + data->state = STATE_BIT_START; + data->count = 1; + DECREASE_DURATION(u, 1); + goto again; + } + break; + + case STATE_BIT_START: + if (DURATION(u) == 1) { + data->rc5_bits <<= 1; + if (IS_SPACE(u)) + data->rc5_bits |= 1; + data->count++; + data->last_unit = u; + + /* + * If the last bit is zero, a space will merge + * with the silence after the command. + */ + if (IS_PULSE(u) && data->count == RC5_NBITS) { + data->state = STATE_FINISHED; + goto again; } - toggle = (scancode & 0x2000) ? 1 : 0; + data->state = STATE_BIT_END; + return 0; + } + break; - if (scancode == data->last_code) { - IR_dprintk(1, "RC-5 repeat\n"); - ir_repeat(input_dev); - } else { - data->last_code = scancode; - scancode &= 0x1fff; - IR_dprintk(1, "RC-5 scancode 0x%04x\n", scancode); + case STATE_BIT_END: + if (IS_TRANSITION(u, data->last_unit)) { + if (data->count == RC5_NBITS) + data->state = STATE_FINISHED; + else + data->state = STATE_BIT_START; - ir_keydown(input_dev, scancode, 0); - } - data->state = STATE_TRAILER; + DECREASE_DURATION(u, 1); + goto again; } - return 0; - case STATE_TRAILER: + break; + + case STATE_FINISHED: + command = (data->rc5_bits & 0x0003F) >> 0; + system = (data->rc5_bits & 0x007C0) >> 6; + toggle = (data->rc5_bits & 0x00800) ? 1 : 0; + command += (data->rc5_bits & 0x01000) ? 0 : 0x40; + scancode = system << 8 | command; + + IR_dprintk(1, "RC5 scancode 0x%04x (toggle: %u)\n", + scancode, toggle); + ir_keydown(input_dev, scancode, toggle); data->state = STATE_INACTIVE; return 0; } -err: - IR_dprintk(1, "RC-5 decoded failed at %s @ %luus\n", - is_pulse ? "pulse" : "space", - (ev->delta.tv_nsec + 500) / 1000); +out: + IR_dprintk(1, "RC5 decode failed at state %i (%i units, %ius)\n", + data->state, u, TO_US(duration)); data->state = STATE_INACTIVE; return -EINVAL; } |