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[media] mceusb: improve ir data buffer parser
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Switch to a state machine that properly handles all incoming urb data
packets, and reads much cleaner and corrects some minor parsing errors
that were hindering decode on cx231xx/Polaris integrated IR. Also tested
with four different mceusb variants, and works perfectly with all of
them (at least for the rc6a mce remotes).

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
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Mauro Carvalho Chehab committed Oct 22, 2010
1 parent 4c8fa38 commit 39dc5c3
Showing 1 changed file with 103 additions and 48 deletions.
151 changes: 103 additions & 48 deletions drivers/media/IR/mceusb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -56,14 +56,16 @@
#define MCE_CODE_LENGTH 5 /* Normal length of packet (with header) */
#define MCE_PACKET_SIZE 4 /* Normal length of packet (without header) */
#define MCE_PACKET_HEADER 0x84 /* Actual header format is 0x80 + num_bytes */
#define MCE_CONTROL_HEADER 0x9F /* MCE status header */
#define MCE_CONTROL_HEADER 0x9f /* MCE status header */
#define MCE_TX_HEADER_LENGTH 3 /* # of bytes in the initializing tx header */
#define MCE_MAX_CHANNELS 2 /* Two transmitters, hardware dependent? */
#define MCE_DEFAULT_TX_MASK 0x03 /* Val opts: TX1=0x01, TX2=0x02, ALL=0x03 */
#define MCE_PULSE_BIT 0x80 /* Pulse bit, MSB set == PULSE else SPACE */
#define MCE_PULSE_MASK 0x7F /* Pulse mask */
#define MCE_MAX_PULSE_LENGTH 0x7F /* Longest transmittable pulse symbol */
#define MCE_PACKET_LENGTH_MASK 0x1F /* Packet length mask */
#define MCE_PULSE_MASK 0x7f /* Pulse mask */
#define MCE_MAX_PULSE_LENGTH 0x7f /* Longest transmittable pulse symbol */
#define MCE_COMMAND_MASK 0xe0 /* Mask out command bits */
#define MCE_PACKET_LENGTH_MASK 0x1f /* Packet length mask */
#define MCE_COMMAND_IRDATA 0x80 /* buf & MCE_COMMAND_MASK == 0x80 -> IR data */


/* module parameters */
Expand Down Expand Up @@ -256,8 +258,15 @@ struct mceusb_dev {
/* buffers and dma */
unsigned char *buf_in;
unsigned int len_in;
u8 cmd; /* MCE command type */
u8 rem; /* Remaining IR data bytes in packet */

enum {
CMD_HEADER = 0,
SUBCMD,
CMD_DATA,
PARSE_IRDATA,
} parser_state;
u8 cmd, rem; /* Remaining IR data bytes in packet */

dma_addr_t dma_in;
dma_addr_t dma_out;

Expand Down Expand Up @@ -302,19 +311,51 @@ struct mceusb_dev {
static char DEVICE_RESET[] = {0x00, 0xff, 0xaa};
static char GET_REVISION[] = {0xff, 0x0b};
static char GET_UNKNOWN[] = {0xff, 0x18};
static char GET_UNKNOWN2[] = {0x9f, 0x05};
static char GET_CARRIER_FREQ[] = {0x9f, 0x07};
static char GET_RX_TIMEOUT[] = {0x9f, 0x0d};
static char GET_TX_BITMASK[] = {0x9f, 0x13};
static char GET_RX_SENSOR[] = {0x9f, 0x15};
static char GET_UNKNOWN2[] = {MCE_CONTROL_HEADER, 0x05};
static char GET_CARRIER_FREQ[] = {MCE_CONTROL_HEADER, 0x07};
static char GET_RX_TIMEOUT[] = {MCE_CONTROL_HEADER, 0x0d};
static char GET_TX_BITMASK[] = {MCE_CONTROL_HEADER, 0x13};
static char GET_RX_SENSOR[] = {MCE_CONTROL_HEADER, 0x15};
/* sub in desired values in lower byte or bytes for full command */
/* FIXME: make use of these for transmit.
static char SET_CARRIER_FREQ[] = {0x9f, 0x06, 0x00, 0x00};
static char SET_TX_BITMASK[] = {0x9f, 0x08, 0x00};
static char SET_RX_TIMEOUT[] = {0x9f, 0x0c, 0x00, 0x00};
static char SET_RX_SENSOR[] = {0x9f, 0x14, 0x00};
static char SET_CARRIER_FREQ[] = {MCE_CONTROL_HEADER, 0x06, 0x00, 0x00};
static char SET_TX_BITMASK[] = {MCE_CONTROL_HEADER, 0x08, 0x00};
static char SET_RX_TIMEOUT[] = {MCE_CONTROL_HEADER, 0x0c, 0x00, 0x00};
static char SET_RX_SENSOR[] = {MCE_CONTROL_HEADER, 0x14, 0x00};
*/

static int mceusb_cmdsize(u8 cmd, u8 subcmd)
{
int datasize = 0;

switch (cmd) {
case 0x00:
if (subcmd == 0xff)
datasize = 1;
break;
case 0xff:
switch (subcmd) {
case 0x0b:
datasize = 2;
break;
}
case MCE_CONTROL_HEADER:
switch (subcmd) {
case 0x04:
case 0x06:
case 0x0c:
case 0x15:
datasize = 2;
break;
case 0x08:
case 0x14:
datasize = 1;
break;
}
}
return datasize;
}

static void mceusb_dev_printdata(struct mceusb_dev *ir, char *buf,
int len, bool out)
{
Expand Down Expand Up @@ -380,7 +421,7 @@ static void mceusb_dev_printdata(struct mceusb_dev *ir, char *buf,
break;
}
break;
case 0x9f:
case MCE_CONTROL_HEADER:
switch (subcmd) {
case 0x03:
dev_info(dev, "Ping\n");
Expand Down Expand Up @@ -629,7 +670,7 @@ static int mceusb_set_tx_carrier(void *priv, u32 carrier)
struct mceusb_dev *ir = priv;
int clk = 10000000;
int prescaler = 0, divisor = 0;
unsigned char cmdbuf[4] = { 0x9f, 0x06, 0x00, 0x00 };
unsigned char cmdbuf[4] = { MCE_CONTROL_HEADER, 0x06, 0x00, 0x00 };

/* Carrier has changed */
if (ir->carrier != carrier) {
Expand Down Expand Up @@ -669,46 +710,33 @@ static int mceusb_set_tx_carrier(void *priv, u32 carrier)
static void mceusb_process_ir_data(struct mceusb_dev *ir, int buf_len)
{
DEFINE_IR_RAW_EVENT(rawir);
int i, start_index = 0;
u8 hdr = MCE_CONTROL_HEADER;
int i = 0;

/* skip meaningless 0xb1 0x60 header bytes on orig receiver */
if (ir->flags.microsoft_gen1)
start_index = 2;

for (i = start_index; i < buf_len;) {
if (ir->rem == 0) {
/* decode mce packets of the form (84),AA,BB,CC,DD */
/* IR data packets can span USB messages - rem */
hdr = ir->buf_in[i];
ir->rem = (hdr & MCE_PACKET_LENGTH_MASK);
ir->cmd = (hdr & ~MCE_PACKET_LENGTH_MASK);
dev_dbg(ir->dev, "New data. rem: 0x%02x, cmd: 0x%02x\n",
ir->rem, ir->cmd);
i++;
}
i = 2;

/* don't process MCE commands */
if (hdr == MCE_CONTROL_HEADER || hdr == 0xff) {
ir->rem = 0;
return;
}

for (; (ir->rem > 0) && (i < buf_len); i++) {
for (; i < buf_len; i++) {
switch (ir->parser_state) {
case SUBCMD:
ir->rem = mceusb_cmdsize(ir->cmd, ir->buf_in[i]);
ir->parser_state = CMD_DATA;
break;
case PARSE_IRDATA:
ir->rem--;

rawir.pulse = ((ir->buf_in[i] & MCE_PULSE_BIT) != 0);
rawir.duration = (ir->buf_in[i] & MCE_PULSE_MASK)
* MCE_TIME_UNIT * 1000;

if ((ir->buf_in[i] & MCE_PULSE_MASK) == 0x7f) {
if (ir->rawir.pulse == rawir.pulse)
if (ir->rawir.pulse == rawir.pulse) {
ir->rawir.duration += rawir.duration;
else {
} else {
ir->rawir.duration = rawir.duration;
ir->rawir.pulse = rawir.pulse;
}
continue;
if (ir->rem)
break;
}
rawir.duration += ir->rawir.duration;
ir->rawir.duration = 0;
Expand All @@ -719,14 +747,40 @@ static void mceusb_process_ir_data(struct mceusb_dev *ir, int buf_len)
rawir.duration);

ir_raw_event_store(ir->idev, &rawir);
break;
case CMD_DATA:
ir->rem--;
break;
case CMD_HEADER:
/* decode mce packets of the form (84),AA,BB,CC,DD */
/* IR data packets can span USB messages - rem */
ir->cmd = ir->buf_in[i];
if ((ir->cmd == MCE_CONTROL_HEADER) ||
((ir->cmd & MCE_COMMAND_MASK) != MCE_COMMAND_IRDATA)) {
ir->parser_state = SUBCMD;
continue;
}
ir->rem = (ir->cmd & MCE_PACKET_LENGTH_MASK);
dev_dbg(ir->dev, "Processing RX data: len = %d\n",
ir->rem);
if (ir->rem) {
ir->parser_state = PARSE_IRDATA;
break;
}
/*
* a package with len=0 (e. g. 0x80) means end of
* data. We could use it to do the call to
* ir_raw_event_handle(). For now, we don't need to
* use it.
*/
break;
}

if (ir->buf_in[i] == 0x80 || ir->buf_in[i] == 0x9f)
ir->rem = 0;

dev_dbg(ir->dev, "calling ir_raw_event_handle\n");
ir_raw_event_handle(ir->idev);
if (ir->parser_state != CMD_HEADER && !ir->rem)
ir->parser_state = CMD_HEADER;
}
dev_dbg(ir->dev, "processed IR data, calling ir_raw_event_handle\n");
ir_raw_event_handle(ir->idev);
}

static void mceusb_dev_recv(struct urb *urb, struct pt_regs *regs)
Expand Down Expand Up @@ -768,6 +822,7 @@ static void mceusb_dev_recv(struct urb *urb, struct pt_regs *regs)

case -EPIPE:
default:
dev_dbg(ir->dev, "Error: urb status = %d\n", urb->status);
break;
}

Expand Down

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