drivers/media/rc/imon_raw.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 //
   3 // Copyright (C) 2018 Sean Young <sean@mess.org>
   4
   5 #include <linux/module.h>
   6 #include <linux/usb.h>
   7 #include <linux/usb/input.h>
   8 #include <media/rc-core.h>
   9
  10 /* Each bit is 250us */
  11 #define BIT_DURATION 250000
  12
  13 struct imon {
  14         struct device *dev;
  15         struct urb *ir_urb;
  16         struct rc_dev *rcdev;
  17         u8 ir_buf[8];
  18         char phys[64];
  19 };
  20
  21 /*
  22  * ffs/find_next_bit() searches in the wrong direction, so open-code our own.
  23  */
  24 static inline int is_bit_set(const u8 *buf, int bit)
  25 {
  26         return buf[bit / 8] & (0x80 >> (bit & 7));
  27 }
  28
  29 static void imon_ir_data(struct imon *imon)
  30 {
  31         DEFINE_IR_RAW_EVENT(rawir);
  32         int offset = 0, size = 5 * 8;
  33         int bit;
  34
  35         dev_dbg(imon->dev, "data: %*ph", 8, imon->ir_buf);
  36
  37         while (offset < size) {
  38                 bit = offset;
  39                 while (!is_bit_set(imon->ir_buf, bit) && bit < size)
  40                         bit++;
  41                 dev_dbg(imon->dev, "pulse: %d bits", bit - offset);
  42                 if (bit > offset) {
  43                         rawir.pulse = true;
  44                         rawir.duration = (bit - offset) * BIT_DURATION;
  45                         ir_raw_event_store_with_filter(imon->rcdev, &rawir);
  46                 }
  47
  48                 if (bit >= size)
  49                         break;
  50
  51                 offset = bit;
  52                 while (is_bit_set(imon->ir_buf, bit) && bit < size)
  53                         bit++;
  54                 dev_dbg(imon->dev, "space: %d bits", bit - offset);
  55
  56                 rawir.pulse = false;
  57                 rawir.duration = (bit - offset) * BIT_DURATION;
  58                 ir_raw_event_store_with_filter(imon->rcdev, &rawir);
  59
  60                 offset = bit;
  61         }
  62
  63         if (imon->ir_buf[7] == 0x0a) {
  64                 ir_raw_event_set_idle(imon->rcdev, true);
  65                 ir_raw_event_handle(imon->rcdev);
  66         }
  67 }
  68
  69 static void imon_ir_rx(struct urb *urb)
  70 {
  71         struct imon *imon = urb->context;
  72         int ret;
  73
  74         switch (urb->status) {
  75         case 0:
  76                 if (imon->ir_buf[7] != 0xff)
  77                         imon_ir_data(imon);
  78                 break;
  79         case -ECONNRESET:
  80         case -ENOENT:
  81         case -ESHUTDOWN:
  82                 usb_unlink_urb(urb);
  83                 return;
  84         case -EPIPE:
  85         default:
  86                 dev_dbg(imon->dev, "error: urb status = %d", urb->status);
  87                 break;
  88         }
  89
  90         ret = usb_submit_urb(urb, GFP_ATOMIC);
  91         if (ret && ret != -ENODEV)
  92                 dev_warn(imon->dev, "failed to resubmit urb: %d", ret);
  93 }
  94
  95 static int imon_probe(struct usb_interface *intf,
  96                       const struct usb_device_id *id)
  97 {
  98         struct usb_endpoint_descriptor *ir_ep = NULL;
  99         struct usb_host_interface *idesc;
 100         struct usb_device *udev;
 101         struct rc_dev *rcdev;
 102         struct imon *imon;
 103         int i, ret;
 104
 105         udev = interface_to_usbdev(intf);
 106         idesc = intf->cur_altsetting;
 107
 108         for (i = 0; i < idesc->desc.bNumEndpoints; i++) {
 109                 struct usb_endpoint_descriptor *ep = &idesc->endpoint[i].desc;
 110
 111                 if (usb_endpoint_is_int_in(ep)) {
 112                         ir_ep = ep;
 113                         break;
 114                 }
 115         }
 116
 117         if (!ir_ep) {
 118                 dev_err(&intf->dev, "IR endpoint missing");
 119                 return -ENODEV;
 120         }
 121
 122         imon = devm_kmalloc(&intf->dev, sizeof(*imon), GFP_KERNEL);
 123         if (!imon)
 124                 return -ENOMEM;
 125
 126         imon->ir_urb = usb_alloc_urb(0, GFP_KERNEL);
 127         if (!imon->ir_urb)
 128                 return -ENOMEM;
 129
 130         imon->dev = &intf->dev;
 131         usb_fill_int_urb(imon->ir_urb, udev,
 132                          usb_rcvintpipe(udev, ir_ep->bEndpointAddress),
 133                          imon->ir_buf, sizeof(imon->ir_buf),
 134                          imon_ir_rx, imon, ir_ep->bInterval);
 135
 136         rcdev = devm_rc_allocate_device(&intf->dev, RC_DRIVER_IR_RAW);
 137         if (!rcdev) {
 138                 ret = -ENOMEM;
 139                 goto free_urb;
 140         }
 141
 142         usb_make_path(udev, imon->phys, sizeof(imon->phys));
 143
 144         rcdev->device_name = "iMON Station";
 145         rcdev->driver_name = KBUILD_MODNAME;
 146         rcdev->input_phys = imon->phys;
 147         usb_to_input_id(udev, &rcdev->input_id);
 148         rcdev->dev.parent = &intf->dev;
 149         rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
 150         rcdev->map_name = RC_MAP_IMON_RSC;
 151         rcdev->rx_resolution = BIT_DURATION;
 152         rcdev->priv = imon;
 153
 154         ret = devm_rc_register_device(&intf->dev, rcdev);
 155         if (ret)
 156                 goto free_urb;
 157
 158         imon->rcdev = rcdev;
 159
 160         ret = usb_submit_urb(imon->ir_urb, GFP_KERNEL);
 161         if (ret)
 162                 goto free_urb;
 163
 164         usb_set_intfdata(intf, imon);
 165
 166         return 0;
 167
 168 free_urb:
 169         usb_free_urb(imon->ir_urb);
 170         return ret;
 171 }
 172
 173 static void imon_disconnect(struct usb_interface *intf)
 174 {
 175         struct imon *imon = usb_get_intfdata(intf);
 176
 177         usb_kill_urb(imon->ir_urb);
 178         usb_free_urb(imon->ir_urb);
 179 }
 180
 181 static const struct usb_device_id imon_table[] = {
 182         /* SoundGraph iMON (IR only) -- sg_imon.inf */
 183         { USB_DEVICE(0x04e8, 0xff30) },
 184         {}
 185 };
 186
 187 static struct usb_driver imon_driver = {
 188         .name = KBUILD_MODNAME,
 189         .probe = imon_probe,
 190         .disconnect = imon_disconnect,
 191         .id_table = imon_table
 192 };
 193
 194 module_usb_driver(imon_driver);
 195
 196 MODULE_DESCRIPTION("Early raw iMON IR devices");
 197 MODULE_AUTHOR("Sean Young <sean@mess.org>");
 198 MODULE_LICENSE("GPL");
 199 MODULE_DEVICE_TABLE(usb, imon_table);