V4L/DVB: staging/lirc: add lirc_ttusbir driver

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/lirc/lirc_ttusbir.c

+/*
+ * lirc_ttusbir.c
+ *
+ * lirc_ttusbir - LIRC device driver for the TechnoTrend USB IR Receiver
+ *
+ * Copyright (C) 2007 Stefan Macher <st_maker-lirc@yahoo.de>
+ *
+ * This LIRC driver provides access to the TechnoTrend USB IR Receiver.
+ * The receiver delivers the IR signal as raw sampled true/false data in
+ * isochronous USB packets each of size 128 byte.
+ * Currently the driver reduces the sampling rate by factor of 8 as this
+ * is still more than enough to decode RC-5 - others should be analyzed.
+ * But the driver does not rely on RC-5 it should be able to decode every
+ * IR signal that is not too fast.
+ */
+
+/*
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+
+#include <media/lirc.h>
+#include <media/lirc_dev.h>
+
+MODULE_DESCRIPTION("TechnoTrend USB IR device driver for LIRC");
+MODULE_AUTHOR("Stefan Macher (st_maker-lirc@yahoo.de)");
+MODULE_LICENSE("GPL");
+
+/* #define DEBUG */
+#ifdef DEBUG
+#define DPRINTK printk
+#else
+#define DPRINTK(_x_, a...)
+#endif
+
+/* function declarations */
+static int probe(struct usb_interface *intf, const struct usb_device_id *id);
+static void disconnect(struct usb_interface *intf);
+static void urb_complete(struct urb *urb);
+static int set_use_inc(void *data);
+static void set_use_dec(void *data);
+
+static int num_urbs = 2;
+module_param(num_urbs, int, S_IRUGO);
+MODULE_PARM_DESC(num_urbs,
+		 "Number of URBs in queue. Try to increase to 4 in case "
+		 "of problems (default: 2; minimum: 2)");
+
+/* table of devices that work with this driver */
+static struct usb_device_id device_id_table[] = {
+	/* TechnoTrend USB IR Receiver */
+	{ USB_DEVICE(0x0B48, 0x2003) },
+	/* Terminating entry */
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, device_id_table);
+
+/* USB driver definition */
+static struct usb_driver usb_driver = {
+	.name = "TTUSBIR",
+	.id_table = &(device_id_table[0]),
+	.probe = probe,
+	.disconnect = disconnect,
+};
+
+/* USB device definition */
+struct ttusbir_device {
+	struct usb_driver *usb_driver;
+	struct usb_device *udev;
+	struct usb_interface *interf;
+	struct usb_class_driver class_driver;
+	unsigned int ifnum; /* Interface number to use */
+	unsigned int alt_setting; /* alternate setting to use */
+	unsigned int endpoint; /* Endpoint to use */
+	struct urb **urb; /* num_urb URB pointers*/
+	char **buffer; /* 128 byte buffer for each URB */
+	struct lirc_buffer rbuf; /* Buffer towards LIRC */
+	struct lirc_driver driver;
+	int minor;
+	int last_pulse; /* remembers if last received byte was pulse or space */
+	int last_num; /* remembers how many last bytes appeared */
+	int opened;
+};
+
+/*** LIRC specific functions ***/
+static int set_use_inc(void *data)
+{
+	int i, retval;
+	struct ttusbir_device *ttusbir = data;
+
+	DPRINTK("Sending first URBs\n");
+	/* @TODO Do I need to check if I am already opened */
+	ttusbir->opened = 1;
+
+	for (i = 0; i < num_urbs; i++) {
+		retval = usb_submit_urb(ttusbir->urb[i], GFP_KERNEL);
+		if (retval) {
+			err("%s: usb_submit_urb failed on urb %d",
+			    __func__, i);
+			return retval;
+		}
+	}
+	return 0;
+}
+
+static void set_use_dec(void *data)
+{
+	struct ttusbir_device *ttusbir = data;
+
+	DPRINTK("Device closed\n");
+
+	ttusbir->opened = 0;
+}
+
+/*** USB specific functions ***/
+
+/*
+ * This mapping table is used to do a very simple filtering of the
+ * input signal.
+ * For a value with at least 4 bits set it returns 0xFF otherwise
+ * 0x00.  For faster IR signals this can not be used. But for RC-5 we
+ * still have about 14 samples per pulse/space, i.e. we sample with 14
+ * times higher frequency than the signal frequency
+ */
+const unsigned char map_table[] =
+{
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0x00, 0x00, 0x00, 0xFF, 0x00, 0xFF, 0xFF, 0xFF,
+	0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
+};
+
+static void urb_complete(struct urb *urb)
+{
+	struct ttusbir_device *ttusbir;
+	unsigned char *buf;
+	int i;
+	int l;
+
+	ttusbir = urb->context;
+
+	if (!ttusbir->opened)
+		return;
+
+	buf = (unsigned char *)urb->transfer_buffer;
+
+	for (i = 0; i < 128; i++) {
+		/* Here we do the filtering and some kind of down sampling */
+		buf[i] = ~map_table[buf[i]];
+		if (ttusbir->last_pulse == buf[i]) {
+			if (ttusbir->last_num < PULSE_MASK/63)
+				ttusbir->last_num++;
+		/*
+		 * else we are in a idle period and do not need to
+		 * increment any longer
+		 */
+		} else {
+			l = ttusbir->last_num * 62; /* about 62 = us/byte */
+			if (ttusbir->last_pulse) /* pulse or space? */
+				l |= PULSE_BIT;
+			if (!lirc_buffer_full(&ttusbir->rbuf)) {
+				lirc_buffer_write(&ttusbir->rbuf, (void *)&l);
+				wake_up_interruptible(&ttusbir->rbuf.wait_poll);
+			}
+			ttusbir->last_num = 0;
+			ttusbir->last_pulse = buf[i];
+		}
+	}
+	usb_submit_urb(urb, GFP_ATOMIC); /* keep data rolling :-) */
+}
+
+/*
+ * Called whenever the USB subsystem thinks we could be the right driver
+ * to handle this device
+ */
+static int probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	int alt_set, endp;
+	int found = 0;
+	int i, j;
+	int struct_size;
+	struct usb_host_interface *host_interf;
+	struct usb_interface_descriptor *interf_desc;
+	struct usb_host_endpoint *host_endpoint;
+	struct ttusbir_device *ttusbir;
+
+	DPRINTK("Module ttusbir probe\n");
+
+	/* To reduce memory fragmentation we use only one allocation */
+	struct_size =  sizeof(struct ttusbir_device) +
+		(sizeof(struct urb *) * num_urbs) +
+		(sizeof(char *) * num_urbs) +
+		(num_urbs * 128);
+	ttusbir = kzalloc(struct_size, GFP_KERNEL);
+	if (!ttusbir)
+		return -ENOMEM;
+
+	ttusbir->urb = (struct urb **)((char *)ttusbir +
+				      sizeof(struct ttusbir_device));
+	ttusbir->buffer = (char **)((char *)ttusbir->urb +
+				   (sizeof(struct urb *) * num_urbs));
+	for (i = 0; i < num_urbs; i++)
+		ttusbir->buffer[i] = (char *)ttusbir->buffer +
+			(sizeof(char *)*num_urbs) + (i * 128);
+
+	ttusbir->usb_driver = &usb_driver;
+	ttusbir->alt_setting = -1;
+	/* @TODO check if error can be returned */
+	ttusbir->udev = usb_get_dev(interface_to_usbdev(intf));
+	ttusbir->interf = intf;
+	ttusbir->last_pulse = 0x00;
+	ttusbir->last_num = 0;
+
+	/*
+	 * Now look for interface setting we can handle
+	 * We are searching for the alt setting where end point
+	 * 0x82 has max packet size 16
+	 */
+	for (alt_set = 0; alt_set < intf->num_altsetting && !found; alt_set++) {
+		host_interf = &intf->altsetting[alt_set];
+		interf_desc = &host_interf->desc;
+		for (endp = 0; endp < interf_desc->bNumEndpoints; endp++) {
+			host_endpoint = &host_interf->endpoint[endp];
+			if ((host_endpoint->desc.bEndpointAddress == 0x82) &&
+			    (host_endpoint->desc.wMaxPacketSize == 0x10)) {
+				ttusbir->alt_setting = alt_set;
+				ttusbir->endpoint = endp;
+				found = 1;
+				break;
+			}
+		}
+	}
+	if (ttusbir->alt_setting != -1)
+		DPRINTK("alt setting: %d\n", ttusbir->alt_setting);
+	else {
+		err("Could not find alternate setting\n");
+		kfree(ttusbir);
+		return -EINVAL;
+	}
+
+	/* OK lets setup this interface setting */
+	usb_set_interface(ttusbir->udev, 0, ttusbir->alt_setting);
+
+	/* Store device info in interface structure */
+	usb_set_intfdata(intf, ttusbir);
+
+	/* Register as a LIRC driver */
+	if (lirc_buffer_init(&ttusbir->rbuf, sizeof(int), 256) < 0) {
+		err("Could not get memory for LIRC data buffer\n");
+		usb_set_intfdata(intf, NULL);
+		kfree(ttusbir);
+		return -ENOMEM;
+	}
+	strcpy(ttusbir->driver.name, "TTUSBIR");
+	ttusbir->driver.minor = -1;
+	ttusbir->driver.code_length = 1;
+	ttusbir->driver.sample_rate = 0;
+	ttusbir->driver.data = ttusbir;
+	ttusbir->driver.add_to_buf = NULL;
+	ttusbir->driver.rbuf = &ttusbir->rbuf;
+	ttusbir->driver.set_use_inc = set_use_inc;
+	ttusbir->driver.set_use_dec = set_use_dec;
+	ttusbir->driver.dev = &intf->dev;
+	ttusbir->driver.owner = THIS_MODULE;
+	ttusbir->driver.features = LIRC_CAN_REC_MODE2;
+	ttusbir->minor = lirc_register_driver(&ttusbir->driver);
+	if (ttusbir->minor < 0) {
+		err("Error registering as LIRC driver\n");
+		usb_set_intfdata(intf, NULL);
+		lirc_buffer_free(&ttusbir->rbuf);
+		kfree(ttusbir);
+		return -EIO;
+	}
+
+	/* Allocate and setup the URB that we will use to talk to the device */
+	for (i = 0; i < num_urbs; i++) {
+		ttusbir->urb[i] = usb_alloc_urb(8, GFP_KERNEL);
+		if (!ttusbir->urb[i]) {
+			err("Could not allocate memory for the URB\n");
+			for (j = i - 1; j >= 0; j--)
+				kfree(ttusbir->urb[j]);
+			lirc_buffer_free(&ttusbir->rbuf);
+			lirc_unregister_driver(ttusbir->minor);
+			kfree(ttusbir);
+			usb_set_intfdata(intf, NULL);
+			return -ENOMEM;
+		}
+		ttusbir->urb[i]->dev = ttusbir->udev;
+		ttusbir->urb[i]->context = ttusbir;
+		ttusbir->urb[i]->pipe = usb_rcvisocpipe(ttusbir->udev,
+							ttusbir->endpoint);
+		ttusbir->urb[i]->interval = 1;
+		ttusbir->urb[i]->transfer_flags = URB_ISO_ASAP;
+		ttusbir->urb[i]->transfer_buffer = &ttusbir->buffer[i][0];
+		ttusbir->urb[i]->complete = urb_complete;
+		ttusbir->urb[i]->number_of_packets = 8;
+		ttusbir->urb[i]->transfer_buffer_length = 128;
+		for (j = 0; j < 8; j++) {
+			ttusbir->urb[i]->iso_frame_desc[j].offset = j*16;
+			ttusbir->urb[i]->iso_frame_desc[j].length = 16;
+		}
+	}
+	return 0;
+}
+
+/**
+ * Called when the driver is unloaded or the device is unplugged
+ */
+static void disconnect(struct usb_interface *intf)
+{
+	int i;
+	struct ttusbir_device *ttusbir;
+
+	DPRINTK("Module ttusbir disconnect\n");
+
+	ttusbir = (struct ttusbir_device *) usb_get_intfdata(intf);
+	usb_set_intfdata(intf, NULL);
+	lirc_unregister_driver(ttusbir->minor);
+	DPRINTK("unregistered\n");
+
+	for (i = 0; i < num_urbs; i++) {
+		usb_kill_urb(ttusbir->urb[i]);
+		usb_free_urb(ttusbir->urb[i]);
+	}
+	DPRINTK("URBs killed\n");
+	lirc_buffer_free(&ttusbir->rbuf);
+	kfree(ttusbir);
+}
+
+static int ttusbir_init_module(void)
+{
+	int result;
+
+	DPRINTK(KERN_DEBUG "Module ttusbir init\n");
+
+	/* register this driver with the USB subsystem */
+	result = usb_register(&usb_driver);
+	if (result)
+		err("usb_register failed. Error number %d", result);
+	return result;
+}
+
+static void ttusbir_exit_module(void)
+{
+	printk(KERN_DEBUG "Module ttusbir exit\n");
+	usb_deregister(&usb_driver);
+}
+
+module_init(ttusbir_init_module);
+module_exit(ttusbir_exit_module);