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 __be64 ir_buf; 18 char phys[64]; 19 }; 20 21 /* 22 * The first 5 bytes of data represent IR pulse or space. Each bit, starting 23 * from highest bit in the first byte, represents 250µs of data. It is 1 24 * for space and 0 for pulse. 25 * 26 * The station sends 10 packets, and the 7th byte will be number 1 to 10, so 27 * when we receive 10 we assume all the data has arrived. 28 */ 29 static void imon_ir_data(struct imon *imon) 30 { 31 struct ir_raw_event rawir = {}; 32 u64 data = be64_to_cpu(imon->ir_buf); 33 u8 packet_no = data & 0xff; 34 int offset = 40; 35 int bit; 36 37 if (packet_no == 0xff) 38 return; 39 40 dev_dbg(imon->dev, "data: %*ph", 8, &imon->ir_buf); 41 42 /* 43 * Only the first 5 bytes contain IR data. Right shift so we move 44 * the IR bits to the lower 40 bits. 45 */ 46 data >>= 24; 47 48 do { 49 /* 50 * Find highest set bit which is less or equal to offset 51 * 52 * offset is the bit above (base 0) where we start looking. 53 * 54 * data & (BIT_ULL(offset) - 1) masks off any unwanted bits, 55 * so we have just bits less than offset. 56 * 57 * fls will tell us the highest bit set plus 1 (or 0 if no 58 * bits are set). 59 */ 60 bit = fls64(data & (BIT_ULL(offset) - 1)); 61 if (bit < offset) { 62 dev_dbg(imon->dev, "pulse: %d bits", offset - bit); 63 rawir.pulse = true; 64 rawir.duration = (offset - bit) * BIT_DURATION; 65 ir_raw_event_store_with_filter(imon->rcdev, &rawir); 66 67 if (bit == 0) 68 break; 69 70 offset = bit; 71 } 72 73 /* 74 * Find highest clear bit which is less than offset. 75 * 76 * Just invert the data and use same trick as above. 77 */ 78 bit = fls64(~data & (BIT_ULL(offset) - 1)); 79 dev_dbg(imon->dev, "space: %d bits", offset - bit); 80 81 rawir.pulse = false; 82 rawir.duration = (offset - bit) * BIT_DURATION; 83 ir_raw_event_store_with_filter(imon->rcdev, &rawir); 84 85 offset = bit; 86 } while (offset > 0); 87 88 if (packet_no == 0x0a && !imon->rcdev->idle) { 89 ir_raw_event_set_idle(imon->rcdev, true); 90 ir_raw_event_handle(imon->rcdev); 91 } 92 } 93 94 static void imon_ir_rx(struct urb *urb) 95 { 96 struct imon *imon = urb->context; 97 int ret; 98 99 switch (urb->status) { 100 case 0: 101 imon_ir_data(imon); 102 break; 103 case -ECONNRESET: 104 case -ENOENT: 105 case -ESHUTDOWN: 106 usb_unlink_urb(urb); 107 return; 108 case -EPIPE: 109 default: 110 dev_dbg(imon->dev, "error: urb status = %d", urb->status); 111 break; 112 } 113 114 ret = usb_submit_urb(urb, GFP_ATOMIC); 115 if (ret && ret != -ENODEV) 116 dev_warn(imon->dev, "failed to resubmit urb: %d", ret); 117 } 118 119 static int imon_probe(struct usb_interface *intf, 120 const struct usb_device_id *id) 121 { 122 struct usb_endpoint_descriptor *ir_ep = NULL; 123 struct usb_host_interface *idesc; 124 struct usb_device *udev; 125 struct rc_dev *rcdev; 126 struct imon *imon; 127 int i, ret; 128 129 udev = interface_to_usbdev(intf); 130 idesc = intf->cur_altsetting; 131 132 for (i = 0; i < idesc->desc.bNumEndpoints; i++) { 133 struct usb_endpoint_descriptor *ep = &idesc->endpoint[i].desc; 134 135 if (usb_endpoint_is_int_in(ep)) { 136 ir_ep = ep; 137 break; 138 } 139 } 140 141 if (!ir_ep) { 142 dev_err(&intf->dev, "IR endpoint missing"); 143 return -ENODEV; 144 } 145 146 imon = devm_kmalloc(&intf->dev, sizeof(*imon), GFP_KERNEL); 147 if (!imon) 148 return -ENOMEM; 149 150 imon->ir_urb = usb_alloc_urb(0, GFP_KERNEL); 151 if (!imon->ir_urb) 152 return -ENOMEM; 153 154 imon->dev = &intf->dev; 155 usb_fill_int_urb(imon->ir_urb, udev, 156 usb_rcvintpipe(udev, ir_ep->bEndpointAddress), 157 &imon->ir_buf, sizeof(imon->ir_buf), 158 imon_ir_rx, imon, ir_ep->bInterval); 159 160 rcdev = devm_rc_allocate_device(&intf->dev, RC_DRIVER_IR_RAW); 161 if (!rcdev) { 162 ret = -ENOMEM; 163 goto free_urb; 164 } 165 166 usb_make_path(udev, imon->phys, sizeof(imon->phys)); 167 168 rcdev->device_name = "iMON Station"; 169 rcdev->driver_name = KBUILD_MODNAME; 170 rcdev->input_phys = imon->phys; 171 usb_to_input_id(udev, &rcdev->input_id); 172 rcdev->dev.parent = &intf->dev; 173 rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER; 174 rcdev->map_name = RC_MAP_IMON_RSC; 175 rcdev->rx_resolution = BIT_DURATION; 176 rcdev->priv = imon; 177 178 ret = devm_rc_register_device(&intf->dev, rcdev); 179 if (ret) 180 goto free_urb; 181 182 imon->rcdev = rcdev; 183 184 ret = usb_submit_urb(imon->ir_urb, GFP_KERNEL); 185 if (ret) 186 goto free_urb; 187 188 usb_set_intfdata(intf, imon); 189 190 return 0; 191 192 free_urb: 193 usb_free_urb(imon->ir_urb); 194 return ret; 195 } 196 197 static void imon_disconnect(struct usb_interface *intf) 198 { 199 struct imon *imon = usb_get_intfdata(intf); 200 201 usb_kill_urb(imon->ir_urb); 202 usb_free_urb(imon->ir_urb); 203 } 204 205 static const struct usb_device_id imon_table[] = { 206 /* SoundGraph iMON (IR only) -- sg_imon.inf */ 207 { USB_DEVICE(0x04e8, 0xff30) }, 208 {} 209 }; 210 211 static struct usb_driver imon_driver = { 212 .name = KBUILD_MODNAME, 213 .probe = imon_probe, 214 .disconnect = imon_disconnect, 215 .id_table = imon_table 216 }; 217 218 module_usb_driver(imon_driver); 219 220 MODULE_DESCRIPTION("Early raw iMON IR devices"); 221 MODULE_AUTHOR("Sean Young <sean@mess.org>"); 222 MODULE_LICENSE("GPL"); 223 MODULE_DEVICE_TABLE(usb, imon_table); 224