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 250 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_cpup(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: %8ph", 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 rawir.pulse = !rawir.pulse; 61 bit = fls64(data & (BIT_ULL(offset) - 1)); 62 if (bit < offset) { 63 dev_dbg(imon->dev, "%s: %d bits", 64 rawir.pulse ? "pulse" : "space", offset - bit); 65 rawir.duration = (offset - bit) * BIT_DURATION; 66 ir_raw_event_store_with_filter(imon->rcdev, &rawir); 67 68 offset = bit; 69 } 70 71 data = ~data; 72 } while (offset > 0); 73 74 if (packet_no == 0x0a && !imon->rcdev->idle) { 75 ir_raw_event_set_idle(imon->rcdev, true); 76 ir_raw_event_handle(imon->rcdev); 77 } 78 } 79 80 static void imon_ir_rx(struct urb *urb) 81 { 82 struct imon *imon = urb->context; 83 int ret; 84 85 switch (urb->status) { 86 case 0: 87 imon_ir_data(imon); 88 break; 89 case -ECONNRESET: 90 case -ENOENT: 91 case -ESHUTDOWN: 92 usb_unlink_urb(urb); 93 return; 94 case -EPIPE: 95 default: 96 dev_dbg(imon->dev, "error: urb status = %d", urb->status); 97 break; 98 } 99 100 ret = usb_submit_urb(urb, GFP_ATOMIC); 101 if (ret && ret != -ENODEV) 102 dev_warn(imon->dev, "failed to resubmit urb: %d", ret); 103 } 104 105 static int imon_probe(struct usb_interface *intf, 106 const struct usb_device_id *id) 107 { 108 struct usb_endpoint_descriptor *ir_ep; 109 struct usb_device *udev; 110 struct rc_dev *rcdev; 111 struct imon *imon; 112 int ret; 113 114 udev = interface_to_usbdev(intf); 115 116 ret = usb_find_int_in_endpoint(intf->cur_altsetting, &ir_ep); 117 if (ret) { 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->ir_buf = kmalloc(sizeof(__be64), GFP_KERNEL); 131 if (!imon->ir_buf) { 132 ret = -ENOMEM; 133 goto free_urb; 134 } 135 136 imon->dev = &intf->dev; 137 usb_fill_int_urb(imon->ir_urb, udev, 138 usb_rcvintpipe(udev, ir_ep->bEndpointAddress), 139 imon->ir_buf, sizeof(__be64), 140 imon_ir_rx, imon, ir_ep->bInterval); 141 142 rcdev = devm_rc_allocate_device(&intf->dev, RC_DRIVER_IR_RAW); 143 if (!rcdev) { 144 ret = -ENOMEM; 145 goto free_urb; 146 } 147 148 usb_make_path(udev, imon->phys, sizeof(imon->phys)); 149 150 rcdev->device_name = "iMON Station"; 151 rcdev->driver_name = KBUILD_MODNAME; 152 rcdev->input_phys = imon->phys; 153 usb_to_input_id(udev, &rcdev->input_id); 154 rcdev->dev.parent = &intf->dev; 155 rcdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER; 156 rcdev->map_name = RC_MAP_IMON_RSC; 157 rcdev->rx_resolution = BIT_DURATION; 158 rcdev->priv = imon; 159 160 ret = devm_rc_register_device(&intf->dev, rcdev); 161 if (ret) 162 goto free_urb; 163 164 imon->rcdev = rcdev; 165 166 ret = usb_submit_urb(imon->ir_urb, GFP_KERNEL); 167 if (ret) 168 goto free_urb; 169 170 usb_set_intfdata(intf, imon); 171 172 return 0; 173 174 free_urb: 175 usb_free_urb(imon->ir_urb); 176 kfree(imon->ir_buf); 177 return ret; 178 } 179 180 static void imon_disconnect(struct usb_interface *intf) 181 { 182 struct imon *imon = usb_get_intfdata(intf); 183 184 usb_kill_urb(imon->ir_urb); 185 usb_free_urb(imon->ir_urb); 186 kfree(imon->ir_buf); 187 } 188 189 static const struct usb_device_id imon_table[] = { 190 /* SoundGraph iMON (IR only) -- sg_imon.inf */ 191 { USB_DEVICE(0x04e8, 0xff30) }, 192 {} 193 }; 194 195 static struct usb_driver imon_driver = { 196 .name = KBUILD_MODNAME, 197 .probe = imon_probe, 198 .disconnect = imon_disconnect, 199 .id_table = imon_table 200 }; 201 202 module_usb_driver(imon_driver); 203 204 MODULE_DESCRIPTION("Early raw iMON IR devices"); 205 MODULE_AUTHOR("Sean Young <sean@mess.org>"); 206 MODULE_LICENSE("GPL"); 207 MODULE_DEVICE_TABLE(usb, imon_table); 208