#include <media/ir-core.h>
+#define NEC_UNIT 559979 /* ns */
+#define NEC_HEADER_MARK (16 * NEC_UNIT)
+#define NEC_HEADER_SPACE (8 * NEC_UNIT)
+#define NEC_REPEAT_SPACE (4 * NEC_UNIT)
+#define NEC_MARK (NEC_UNIT)
+#define NEC_0_SYMBOL (NEC_UNIT)
+#define NEC_1_SYMBOL (3 * NEC_UNIT)
+
/* Start time: 4.5 ms + 560 us of the next pulse */
#define MIN_START_TIME (3900000 + 560000)
#define MAX_START_TIME (5100000 + 560000)
static LIST_HEAD(decoder_list);
static spinlock_t decoder_lock;
+enum nec_state {
+ STATE_INACTIVE,
+ STATE_HEADER_MARK,
+ STATE_HEADER_SPACE,
+ STATE_MARK,
+ STATE_SPACE,
+ STATE_TRAILER_MARK,
+ STATE_TRAILER_SPACE,
+};
+
+struct nec_code {
+ u8 address;
+ u8 not_address;
+ u8 command;
+ u8 not_command;
+};
+
struct decoder_data {
struct list_head list;
struct ir_input_dev *ir_dev;
int enabled:1;
+
+ /* State machine control */
+ enum nec_state state;
+ struct nec_code nec_code;
+ unsigned count;
};
};
-/** is_repeat - Check if it is a NEC repeat event
+/**
+ * handle_event() - Decode one NEC pulse or space
* @input_dev: the struct input_dev descriptor of the device
- * @pos: the position of the first event
- * @len: the length of the buffer
+ * @ev: event array with type/duration of pulse/space
+ *
+ * This function returns -EINVAL if the pulse violates the state machine
*/
-static int is_repeat(struct ir_raw_event *evs, int len, int pos)
+static int handle_event(struct input_dev *input_dev,
+ struct ir_raw_event *ev)
{
- if ((evs[pos].delta.tv_nsec < MIN_REPEAT_START_TIME) ||
- (evs[pos].delta.tv_nsec > MAX_REPEAT_START_TIME))
- return 0;
+ struct decoder_data *data;
+ struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
+ int bit, last_bit;
- if (++pos >= len)
- return 0;
+ data = get_decoder_data(ir_dev);
+ if (!data)
+ return -EINVAL;
- if ((evs[pos].delta.tv_nsec < MIN_REPEAT_TIME) ||
- (evs[pos].delta.tv_nsec > MAX_REPEAT_TIME))
- return 0;
+ /* Except for the initial event, what matters is the previous bit */
+ bit = (ev->type & IR_PULSE) ? 1 : 0;
- return 1;
-}
+ last_bit = !bit;
-/**
- * __ir_nec_decode() - Decode one NEC pulsecode
- * @input_dev: the struct input_dev descriptor of the device
- * @evs: event array with type/duration of pulse/space
- * @len: length of the array
- * @pos: position to start seeking for a code
- * This function returns -EINVAL if no pulse got decoded,
- * 0 if buffer is empty and 1 if one keycode were handled.
- */
-static int __ir_nec_decode(struct input_dev *input_dev,
- struct ir_raw_event *evs,
- int len, int *pos)
-{
- struct ir_input_dev *ir = input_get_drvdata(input_dev);
- int count = -1;
- int ircode = 0, not_code = 0;
-
- /* Be sure that the first event is an start one and is a pulse */
- for (; *pos < len; (*pos)++) {
- /* Very long delays are considered as start events */
- if (evs[*pos].delta.tv_nsec > MAX_NEC_TIME)
- break;
- if (evs[*pos].type & IR_START_EVENT)
- break;
- IR_dprintk(1, "%luus: Spurious NEC %s\n",
- (evs[*pos].delta.tv_nsec + 500) / 1000,
- (evs[*pos].type & IR_SPACE) ? "space" : "pulse");
+ /* Discards spurious space last_bits when inactive */
- }
- if (*pos >= len)
- return 0;
+ /* Very long delays are considered as start events */
+ if (ev->delta.tv_nsec > NEC_HEADER_MARK + NEC_HEADER_SPACE - NEC_UNIT / 2)
+ data->state = STATE_INACTIVE;
- (*pos)++; /* First event doesn't contain data */
+ if (ev->type & IR_START_EVENT)
+ data->state = STATE_INACTIVE;
- if (evs[*pos].type != IR_PULSE)
- goto err;
+ switch (data->state) {
+ case STATE_INACTIVE:
+ if (!bit) /* PULSE marks the start event */
+ return 0;
- /* Check if it is a NEC repeat event */
- if (is_repeat(evs, len, *pos)) {
- *pos += 2;
- if (ir->keypressed) {
- ir_repeat(input_dev);
- IR_dprintk(1, "NEC repeat event\n");
- return 1;
- } else {
- IR_dprintk(1, "missing NEC repeat event\n");
+ data->count = 0;
+ data->state = STATE_HEADER_MARK;
+ memset (&data->nec_code, 0, sizeof(data->nec_code));
+ return 0;
+ case STATE_HEADER_MARK:
+ if (!last_bit)
+ goto err;
+ if (ev->delta.tv_nsec < NEC_HEADER_MARK - 6 * NEC_UNIT)
+ goto err;
+ data->state = STATE_HEADER_SPACE;
+ return 0;
+ case STATE_HEADER_SPACE:
+ if (last_bit)
+ goto err;
+ if (ev->delta.tv_nsec >= NEC_HEADER_SPACE - NEC_UNIT / 2) {
+ data->state = STATE_MARK;
return 0;
}
- }
- /* First space should have 4.5 ms otherwise is not NEC protocol */
- if ((evs[*pos].delta.tv_nsec < MIN_START_TIME) ||
- (evs[*pos].delta.tv_nsec > MAX_START_TIME))
+ if (ev->delta.tv_nsec >= NEC_REPEAT_SPACE - NEC_UNIT / 2) {
+ ir_repeat(input_dev);
+ IR_dprintk(1, "Repeat last key\n");
+ data->state = STATE_TRAILER_MARK;
+ return 0;
+ }
goto err;
+ case STATE_MARK:
+ if (!last_bit)
+ goto err;
+ if ((ev->delta.tv_nsec > NEC_MARK + NEC_UNIT / 2) ||
+ (ev->delta.tv_nsec < NEC_MARK - NEC_UNIT / 2))
+ goto err;
+ data->state = STATE_SPACE;
+ return 0;
+ case STATE_SPACE:
+ if (last_bit)
+ goto err;
- count = 0;
- for ((*pos)++; *pos < len; (*pos)++) {
- int bit;
- if ((evs[*pos].delta.tv_nsec > MIN_BIT1_TIME) &&
- (evs[*pos].delta.tv_nsec < MAX_BIT1_TIME))
- bit = 1;
- else if ((evs[*pos].delta.tv_nsec > MIN_BIT0_TIME) &&
- (evs[*pos].delta.tv_nsec < MAX_BIT0_TIME))
+ if ((ev->delta.tv_nsec >= NEC_0_SYMBOL - NEC_UNIT / 2) &&
+ (ev->delta.tv_nsec < NEC_0_SYMBOL + NEC_UNIT / 2))
bit = 0;
- else
- goto err;
+ else if ((ev->delta.tv_nsec >= NEC_1_SYMBOL - NEC_UNIT / 2) &&
+ (ev->delta.tv_nsec < NEC_1_SYMBOL + NEC_UNIT / 2))
+ bit = 1;
+ else {
+ IR_dprintk(1, "Decode failed at %d-th bit (%s) @%luus\n",
+ data->count,
+ last_bit ? "pulse" : "space",
+ (ev->delta.tv_nsec + 500) / 1000);
+
+ goto err2;
+ }
+ /* Ok, we've got a valid bit. proccess it */
if (bit) {
- int shift = count;
- /* Address first, then command */
+ int shift = data->count;
+
+ /*
+ * NEC transmit bytes on this temporal order:
+ * address | not address | command | not command
+ */
if (shift < 8) {
- shift += 8;
- ircode |= 1 << shift;
+ data->nec_code.address |= 1 << shift;
} else if (shift < 16) {
- not_code |= 1 << shift;
+ data->nec_code.not_address |= 1 << (shift - 8);
} else if (shift < 24) {
- shift -= 16;
- ircode |= 1 << shift;
+ data->nec_code.command |= 1 << (shift - 16);
} else {
- shift -= 24;
- not_code |= 1 << shift;
+ data->nec_code.not_command |= 1 << (shift - 24);
}
}
- if (++count == 32)
- break;
- }
- (*pos)++;
-
- /*
- * Fixme: may need to accept Extended NEC protocol?
- */
- if ((ircode & ~not_code) != ircode) {
- IR_dprintk(1, "NEC checksum error: code 0x%04x, not-code 0x%04x\n",
- ircode, not_code);
- return -EINVAL;
- }
+ if (++data->count == 32) {
+ u32 scancode;
+ /*
+ * Fixme: may need to accept Extended NEC protocol?
+ */
+ if ((data->nec_code.command ^ data->nec_code.not_command) != 0xff)
+ goto checksum_err;
+
+ if ((data->nec_code.address ^ data->nec_code.not_address) != 0xff) {
+ /* Extended NEC */
+ scancode = data->nec_code.address << 16 |
+ data->nec_code.not_address << 8 |
+ data->nec_code.command;
+ IR_dprintk(1, "NEC scancode 0x%06x\n", scancode);
+ } else {
+ /* normal NEC */
+ scancode = data->nec_code.address << 8 |
+ data->nec_code.command;
+ IR_dprintk(1, "NEC scancode 0x%04x\n", scancode);
+ }
+ ir_keydown(input_dev, scancode, 0);
- IR_dprintk(1, "NEC scancode 0x%04x\n", ircode);
- ir_keydown(input_dev, ircode, 0);
+ data->state = STATE_TRAILER_MARK;
+ } else
+ data->state = STATE_MARK;
+ return 0;
+ case STATE_TRAILER_MARK:
+ if (!last_bit)
+ goto err;
+ data->state = STATE_TRAILER_SPACE;
+ return 0;
+ case STATE_TRAILER_SPACE:
+ if (last_bit)
+ goto err;
+ data->state = STATE_INACTIVE;
+ return 0;
+ }
- return 1;
err:
- IR_dprintk(1, "NEC decoded failed at bit %d (%s) while decoding %luus time\n",
- count,
- (evs[*pos].type & IR_SPACE) ? "space" : "pulse",
- (evs[*pos].delta.tv_nsec + 500) / 1000);
+ IR_dprintk(1, "NEC decoded failed at state %d (%s) @ %luus\n",
+ data->state,
+ bit ? "pulse" : "space",
+ (ev->delta.tv_nsec + 500) / 1000);
+err2:
+ data->state = STATE_INACTIVE;
+ return -EINVAL;
+checksum_err:
+ data->state = STATE_INACTIVE;
+ IR_dprintk(1, "NEC checksum error: received 0x%02x%02x%02x%02x\n",
+ data->nec_code.address,
+ data->nec_code.not_address,
+ data->nec_code.command,
+ data->nec_code.not_command);
return -EINVAL;
}
/**
- * __ir_nec_decode() - Decodes all NEC pulsecodes on a given array
+ * ir_nec_decode() - Decodes all NEC pulsecodes on a given array
* @input_dev: the struct input_dev descriptor of the device
* @evs: event array with type/duration of pulse/space
* @len: length of the array
if (!data || !data->enabled)
return 0;
- while (pos < len) {
- if (__ir_nec_decode(input_dev, evs, len, &pos) > 0)
- rc++;
- }
+ for (pos = 0; pos < len; pos++)
+ handle_event(input_dev, &evs[pos]);
+
return rc;
}
git.openpandora.org / pandora-kernel.git / blobdiff