V4L/DVB: gspca_xirlink_cit: support bandwidth changing for devices with 1 alt setting

Some xirlink_cit models have only 1 alt setting, but the actual used
bandwidth can be programmed through a register use this to allow streaming
while other isoc streams (for example sound) are active at the same time.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/gspca/xirlink_cit.c b/drivers/media/video/gspca/xirlink_cit.c
index b13ecba..c4e9b8c 100644 (file)
--- a/drivers/media/video/gspca/xirlink_cit.c
+++ b/drivers/media/video/gspca/xirlink_cit.c
@@ -2758,6 +2758,25 @@ static int sd_start(struct gspca_dev *gspca_dev)
        return 0;
 }
 
+static int sd_isoc_nego(struct gspca_dev *gspca_dev)
+{
+       int ret, packet_size;
+       struct usb_host_interface *alt;
+
+       alt = &gspca_dev->dev->config->intf_cache[0]->altsetting[1];
+       packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
+       packet_size -= 100;
+       if (packet_size < 300)
+               return -EIO;
+       alt->endpoint[0].desc.wMaxPacketSize = cpu_to_le16(packet_size);
+
+       ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, 1);
+       if (ret < 0)
+               PDEBUG(D_ERR|D_STREAM, "set alt 1 err %d", ret);
+
+       return ret;
+}
+
 static void sd_stopN(struct gspca_dev *gspca_dev)
 {
        cit_write_reg(gspca_dev, 0x0000, 0x010c);
@@ -2766,12 +2785,15 @@ static void sd_stopN(struct gspca_dev *gspca_dev)
 static void sd_stop0(struct gspca_dev *gspca_dev)
 {
        struct sd *sd = (struct sd *) gspca_dev;
+       struct usb_host_interface *alt;
 
        /* We cannot use gspca_dev->present here as that is not set when
           sd_init gets called and we get called from sd_init */
        if (!gspca_dev->dev)
                return;
 
+       alt = &gspca_dev->dev->config->intf_cache[0]->altsetting[1];
+
        switch (sd->model) {
        case CIT_MODEL0:
                /* HDG windows does this, but it causes the cams autogain to
@@ -2826,6 +2848,10 @@ static void sd_stop0(struct gspca_dev *gspca_dev)
                   restarting the stream after this */
                /* cit_write_reg(gspca_dev, 0x0000, 0x0112); */
                cit_write_reg(gspca_dev, 0x00c0, 0x0100);
+
+               /* Start isoc bandwidth "negotiation" at max isoc bandwith
+                  next stream start */
+               alt->endpoint[0].desc.wMaxPacketSize = cpu_to_le16(1022);
                break;
        }
 }
@@ -3135,6 +3161,19 @@ static const struct sd_desc sd_desc = {
        .pkt_scan = sd_pkt_scan,
 };
 
+static const struct sd_desc sd_desc_isoc_nego = {
+       .name = MODULE_NAME,
+       .ctrls = sd_ctrls,
+       .nctrls = ARRAY_SIZE(sd_ctrls),
+       .config = sd_config,
+       .init = sd_init,
+       .start = sd_start,
+       .isoc_nego = sd_isoc_nego,
+       .stopN = sd_stopN,
+       .stop0 = sd_stop0,
+       .pkt_scan = sd_pkt_scan,
+};
+
 /* -- module initialisation -- */
 static const __devinitdata struct usb_device_id device_table[] = {
        { USB_DEVICE_VER(0x0545, 0x8080, 0x0001, 0x0001), .driver_info = CIT_MODEL0 },
@@ -3152,6 +3191,8 @@ MODULE_DEVICE_TABLE(usb, device_table);
 static int sd_probe(struct usb_interface *intf,
                        const struct usb_device_id *id)
 {
+       const struct sd_desc *desc = &sd_desc;
+
        switch (id->driver_info) {
        case CIT_MODEL0:
        case CIT_MODEL1:
@@ -3159,16 +3200,21 @@ static int sd_probe(struct usb_interface *intf,
                        return -ENODEV;
                break;
        case CIT_MODEL2:
-       case CIT_MODEL3:
        case CIT_MODEL4:
-       case CIT_IBM_NETCAM_PRO:
                if (intf->cur_altsetting->desc.bInterfaceNumber != 0)
                        return -ENODEV;
                break;
+       case CIT_MODEL3:
+               if (intf->cur_altsetting->desc.bInterfaceNumber != 0)
+                       return -ENODEV;
+               /* FIXME this likely applies to all model3 cams and probably
+                  to other models too. */
+               if (ibm_netcam_pro)
+                       desc = &sd_desc_isoc_nego;
+               break;
        }
 
-       return gspca_dev_probe2(intf, id, &sd_desc, sizeof(struct sd),
-                               THIS_MODULE);
+       return gspca_dev_probe2(intf, id, desc, sizeof(struct sd), THIS_MODULE);
 }
 
 static struct usb_driver sd_driver = {