V4L/DVB (13930): dib0700: rework IR logic for firmware 1.20

When firmware 1.20 was introduced, the dib0700 switched from a polling model
using a USB control message, to the messages being delivered on a USB bulk
pipe.  The code I originally added would do a blocking read on the pipe with a
50ms timeout.  Because the dvb-usb-remote code makes use of the global
workqueue, this resulted in the global workqueue being blocked 50% of the
time.  Also, the synchronous urb_bulk_msg() call would burn excess CPU time
(reflected as an abnormal increase in the system's load average when devices
were connected).

Rework the logic so that we now setup an asynchronous callback on the bulk
pipe, so that we now only handle RC data when it arrives on the pipe.  Note
that we provide a stub function for the RC polling callback so that we can
continue to leverage the shared code in dvb-usb-rc for the setting up of the
input device.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 195 insertions, 1 deletions

diff --git a/drivers/media/dvb/dvb-usb/dib0700_core.c b/drivers/media/dvb/dvb-usb/dib0700_core.c
index 0d3c9a9..4450214 100644
--- a/drivers/media/dvb/dvb-usb/dib0700_core.c
+++ b/drivers/media/dvb/dvb-usb/dib0700_core.c
@@ -471,14 +471,208 @@ int dib0700_streaming_ctrl(struct dvb_usb_adapter *adap, int onoff)
 	return dib0700_ctrl_wr(adap->dev, b, 4);
 }
 
+/* Number of keypresses to ignore before start repeating */
+#define RC_REPEAT_DELAY_V1_20 10
+
+/* This is the structure of the RC response packet starting in firmware 1.20 */
+struct dib0700_rc_response {
+	u8 report_id;
+	u8 data_state;
+	u16 system;
+	u8 data;
+	u8 not_data;
+};
+#define RC_MSG_SIZE_V1_20 6
+
+static void dib0700_rc_urb_completion(struct urb *purb)
+{
+	struct dvb_usb_device *d = purb->context;
+	struct dvb_usb_rc_key *keymap;
+	struct dib0700_state *st;
+	struct dib0700_rc_response poll_reply;
+	u8 *buf;
+	int found = 0;
+	u32 event;
+	int state;
+	int i;
+
+	deb_info("%s()\n", __func__);
+	if (d == NULL)
+		return;
+
+	if (d->rc_input_dev == NULL) {
+		/* This will occur if disable_rc_polling=1 */
+		usb_free_urb(purb);
+		return;
+	}
+
+	keymap = d->props.rc_key_map;
+	st = d->priv;
+	buf = (u8 *)purb->transfer_buffer;
+
+	if (purb->status < 0) {
+		deb_info("discontinuing polling\n");
+		usb_free_urb(purb);
+		return;
+	}
+
+	if (purb->actual_length != RC_MSG_SIZE_V1_20) {
+		deb_info("malformed rc msg size=%d\n", purb->actual_length);
+		goto resubmit;
+	}
+
+	/* Set initial results in case we exit the function early */
+	event = 0;
+	state = REMOTE_NO_KEY_PRESSED;
+
+	deb_data("IR raw %02X %02X %02X %02X %02X %02X (len %d)\n", buf[0],
+		 buf[1], buf[2], buf[3], buf[4], buf[5], purb->actual_length);
+
+	switch (dvb_usb_dib0700_ir_proto) {
+	case 0:
+		/* NEC Protocol */
+		poll_reply.report_id  = 0;
+		poll_reply.data_state = 1;
+		poll_reply.system     = buf[2];
+		poll_reply.data       = buf[4];
+		poll_reply.not_data   = buf[5];
+
+		/* NEC protocol sends repeat code as 0 0 0 FF */
+		if ((poll_reply.system == 0x00) && (poll_reply.data == 0x00)
+		    && (poll_reply.not_data == 0xff)) {
+			poll_reply.data_state = 2;
+			break;
+		}
+		break;
+	default:
+		/* RC5 Protocol */
+		poll_reply.report_id  = buf[0];
+		poll_reply.data_state = buf[1];
+		poll_reply.system     = (buf[2] << 8) | buf[3];
+		poll_reply.data       = buf[4];
+		poll_reply.not_data   = buf[5];
+		break;
+	}
+
+	if ((poll_reply.data + poll_reply.not_data) != 0xff) {
+		/* Key failed integrity check */
+		err("key failed integrity check: %04x %02x %02x",
+		    poll_reply.system,
+		    poll_reply.data, poll_reply.not_data);
+		goto resubmit;
+	}
+
+	deb_data("rid=%02x ds=%02x sm=%04x d=%02x nd=%02x\n",
+		 poll_reply.report_id, poll_reply.data_state,
+		 poll_reply.system, poll_reply.data, poll_reply.not_data);
+
+	/* Find the key in the map */
+	for (i = 0; i < d->props.rc_key_map_size; i++) {
+		if (rc5_custom(&keymap[i]) == (poll_reply.system & 0xff) &&
+		    rc5_data(&keymap[i]) == poll_reply.data) {
+			event = keymap[i].event;
+			found = 1;
+			break;
+		}
+	}
+
+	if (found == 0) {
+		err("Unknown remote controller key: %04x %02x %02x",
+		    poll_reply.system, poll_reply.data, poll_reply.not_data);
+		d->last_event = 0;
+		goto resubmit;
+	}
+
+	if (poll_reply.data_state == 1) {
+		/* New key hit */
+		st->rc_counter = 0;
+		event = keymap[i].event;
+		state = REMOTE_KEY_PRESSED;
+		d->last_event = keymap[i].event;
+	} else if (poll_reply.data_state == 2) {
+		/* Key repeated */
+		st->rc_counter++;
+
+		/* prevents unwanted double hits */
+		if (st->rc_counter > RC_REPEAT_DELAY_V1_20) {
+			event = d->last_event;
+			state = REMOTE_KEY_PRESSED;
+			st->rc_counter = RC_REPEAT_DELAY_V1_20;
+		}
+	} else {
+		err("Unknown data state [%d]", poll_reply.data_state);
+	}
+
+	switch (state) {
+	case REMOTE_NO_KEY_PRESSED:
+		break;
+	case REMOTE_KEY_PRESSED:
+		deb_info("key pressed\n");
+		d->last_event = event;
+	case REMOTE_KEY_REPEAT:
+		deb_info("key repeated\n");
+		input_event(d->rc_input_dev, EV_KEY, event, 1);
+		input_event(d->rc_input_dev, EV_KEY, d->last_event, 0);
+		input_sync(d->rc_input_dev);
+		break;
+	default:
+		break;
+	}
+
+resubmit:
+	/* Clean the buffer before we requeue */
+	memset(purb->transfer_buffer, 0, RC_MSG_SIZE_V1_20);
+
+	/* Requeue URB */
+	usb_submit_urb(purb, GFP_ATOMIC);
+}
+
 int dib0700_rc_setup(struct dvb_usb_device *d)
 {
+	struct dib0700_state *st = d->priv;
 	u8 rc_setup[3] = {REQUEST_SET_RC, dvb_usb_dib0700_ir_proto, 0};
-	int i = dib0700_ctrl_wr(d, rc_setup, 3);
+	struct urb *purb;
+	int ret;
+	int i;
+
+	if (d->props.rc_key_map == NULL)
+		return 0;
+
+	/* Set the IR mode */
+	i = dib0700_ctrl_wr(d, rc_setup, 3);
 	if (i<0) {
 		err("ir protocol setup failed");
 		return -1;
 	}
+
+	if (st->fw_version < 0x10200)
+		return 0;
+
+	/* Starting in firmware 1.20, the RC info is provided on a bulk pipe */
+	purb = usb_alloc_urb(0, GFP_KERNEL);
+	if (purb == NULL) {
+		err("rc usb alloc urb failed\n");
+		return -1;
+	}
+
+	purb->transfer_buffer = kzalloc(RC_MSG_SIZE_V1_20, GFP_KERNEL);
+	if (purb->transfer_buffer == NULL) {
+		err("rc kzalloc failed\n");
+		usb_free_urb(purb);
+		return -1;
+	}
+
+	purb->status = -EINPROGRESS;
+	usb_fill_bulk_urb(purb, d->udev, usb_rcvbulkpipe(d->udev, 1),
+			  purb->transfer_buffer, RC_MSG_SIZE_V1_20,
+			  dib0700_rc_urb_completion, d);
+
+	ret = usb_submit_urb(purb, GFP_ATOMIC);
+	if (ret != 0) {
+		err("rc submit urb failed\n");
+		return -1;
+	}
+
 	return 0;
 }