drivers/input/joystick/iforce/iforce-serio.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Copyright (c) 2000-2001 Vojtech Pavlik <vojtech@ucw.cz>
   4  *  Copyright (c) 2001, 2007 Johann Deneux <johann.deneux@gmail.com>
   5  *
   6  *  USB/RS232 I-Force joysticks and wheels.
   7  */
   8
   9 #include <linux/serio.h>
  10 #include "iforce.h"
  11
  12 struct iforce_serio {
  13         struct iforce iforce;
  14
  15         struct serio *serio;
  16         int idx, pkt, len, id;
  17         u8 csum;
  18         u8 expect_packet;
  19         u8 cmd_response[IFORCE_MAX_LENGTH];
  20         u8 cmd_response_len;
  21         u8 data_in[IFORCE_MAX_LENGTH];
  22 };
  23
  24 static void iforce_serio_xmit(struct iforce *iforce)
  25 {
  26         struct iforce_serio *iforce_serio = container_of(iforce,
  27                                                          struct iforce_serio,
  28                                                          iforce);
  29         unsigned char cs;
  30         int i;
  31         unsigned long flags;
  32
  33         if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) {
  34                 set_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags);
  35                 return;
  36         }
  37
  38         spin_lock_irqsave(&iforce->xmit_lock, flags);
  39
  40 again:
  41         if (iforce->xmit.head == iforce->xmit.tail) {
  42                 clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);
  43                 spin_unlock_irqrestore(&iforce->xmit_lock, flags);
  44                 return;
  45         }
  46
  47         cs = 0x2b;
  48
  49         serio_write(iforce_serio->serio, 0x2b);
  50
  51         serio_write(iforce_serio->serio, iforce->xmit.buf[iforce->xmit.tail]);
  52         cs ^= iforce->xmit.buf[iforce->xmit.tail];
  53         XMIT_INC(iforce->xmit.tail, 1);
  54
  55         for (i=iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) {
  56                 serio_write(iforce_serio->serio,
  57                             iforce->xmit.buf[iforce->xmit.tail]);
  58                 cs ^= iforce->xmit.buf[iforce->xmit.tail];
  59                 XMIT_INC(iforce->xmit.tail, 1);
  60         }
  61
  62         serio_write(iforce_serio->serio, cs);
  63
  64         if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags))
  65                 goto again;
  66
  67         clear_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags);
  68
  69         spin_unlock_irqrestore(&iforce->xmit_lock, flags);
  70 }
  71
  72 static int iforce_serio_get_id(struct iforce *iforce, u8 id,
  73                                u8 *response_data, size_t *response_len)
  74 {
  75         struct iforce_serio *iforce_serio = container_of(iforce,
  76                                                          struct iforce_serio,
  77                                                          iforce);
  78
  79         iforce_serio->expect_packet = HI(FF_CMD_QUERY);
  80         iforce_serio->cmd_response_len = 0;
  81
  82         iforce_send_packet(iforce, FF_CMD_QUERY, &id);
  83
  84         wait_event_interruptible_timeout(iforce->wait,
  85                                          !iforce_serio->expect_packet, HZ);
  86
  87         if (iforce_serio->expect_packet) {
  88                 iforce_serio->expect_packet = 0;
  89                 return -ETIMEDOUT;
  90         }
  91
  92         if (iforce_serio->cmd_response[0] != id)
  93                 return -EIO;
  94
  95         memcpy(response_data, iforce_serio->cmd_response,
  96                iforce_serio->cmd_response_len);
  97         *response_len = iforce_serio->cmd_response_len;
  98
  99         return 0;
 100 }
 101
 102 static int iforce_serio_start_io(struct iforce *iforce)
 103 {
 104         /* No special handling required */
 105         return 0;
 106 }
 107
 108 static void iforce_serio_stop_io(struct iforce *iforce)
 109 {
 110         //TODO: Wait for the last packets to be sent
 111 }
 112
 113 static const struct iforce_xport_ops iforce_serio_xport_ops = {
 114         .xmit           = iforce_serio_xmit,
 115         .get_id         = iforce_serio_get_id,
 116         .start_io       = iforce_serio_start_io,
 117         .stop_io        = iforce_serio_stop_io,
 118 };
 119
 120 static void iforce_serio_write_wakeup(struct serio *serio)
 121 {
 122         struct iforce *iforce = serio_get_drvdata(serio);
 123
 124         iforce_serio_xmit(iforce);
 125 }
 126
 127 static irqreturn_t iforce_serio_irq(struct serio *serio,
 128                                     unsigned char data, unsigned int flags)
 129 {
 130         struct iforce_serio *iforce_serio = serio_get_drvdata(serio);
 131         struct iforce *iforce = &iforce_serio->iforce;
 132
 133         if (!iforce_serio->pkt) {
 134                 if (data == 0x2b)
 135                         iforce_serio->pkt = 1;
 136                 goto out;
 137         }
 138
 139         if (!iforce_serio->id) {
 140                 if (data > 3 && data != 0xff)
 141                         iforce_serio->pkt = 0;
 142                 else
 143                         iforce_serio->id = data;
 144                 goto out;
 145         }
 146
 147         if (!iforce_serio->len) {
 148                 if (data > IFORCE_MAX_LENGTH) {
 149                         iforce_serio->pkt = 0;
 150                         iforce_serio->id = 0;
 151                 } else {
 152                         iforce_serio->len = data;
 153                 }
 154                 goto out;
 155         }
 156
 157         if (iforce_serio->idx < iforce_serio->len) {
 158                 iforce_serio->data_in[iforce_serio->idx++] = data;
 159                 iforce_serio->csum += data;
 160                 goto out;
 161         }
 162
 163         if (iforce_serio->idx == iforce_serio->len) {
 164                 /* Handle command completion */
 165                 if (iforce_serio->expect_packet == iforce_serio->id) {
 166                         iforce_serio->expect_packet = 0;
 167                         memcpy(iforce_serio->cmd_response,
 168                                iforce_serio->data_in, IFORCE_MAX_LENGTH);
 169                         iforce_serio->cmd_response_len = iforce_serio->len;
 170
 171                         /* Signal that command is done */
 172                         wake_up(&iforce->wait);
 173                 } else if (likely(iforce->type)) {
 174                         iforce_process_packet(iforce, iforce_serio->id,
 175                                               iforce_serio->data_in,
 176                                               iforce_serio->len);
 177                 }
 178
 179                 iforce_serio->pkt = 0;
 180                 iforce_serio->id  = 0;
 181                 iforce_serio->len = 0;
 182                 iforce_serio->idx = 0;
 183                 iforce_serio->csum = 0;
 184         }
 185 out:
 186         return IRQ_HANDLED;
 187 }
 188
 189 static int iforce_serio_connect(struct serio *serio, struct serio_driver *drv)
 190 {
 191         struct iforce_serio *iforce_serio;
 192         int err;
 193
 194         iforce_serio = kzalloc(sizeof(*iforce_serio), GFP_KERNEL);
 195         if (!iforce_serio)
 196                 return -ENOMEM;
 197
 198         iforce_serio->iforce.xport_ops = &iforce_serio_xport_ops;
 199
 200         iforce_serio->serio = serio;
 201         serio_set_drvdata(serio, iforce_serio);
 202
 203         err = serio_open(serio, drv);
 204         if (err)
 205                 goto fail1;
 206
 207         err = iforce_init_device(&serio->dev, BUS_RS232, &iforce_serio->iforce);
 208         if (err)
 209                 goto fail2;
 210
 211         return 0;
 212
 213  fail2: serio_close(serio);
 214  fail1: serio_set_drvdata(serio, NULL);
 215         kfree(iforce_serio);
 216         return err;
 217 }
 218
 219 static void iforce_serio_disconnect(struct serio *serio)
 220 {
 221         struct iforce_serio *iforce_serio = serio_get_drvdata(serio);
 222
 223         input_unregister_device(iforce_serio->iforce.dev);
 224         serio_close(serio);
 225         serio_set_drvdata(serio, NULL);
 226         kfree(iforce_serio);
 227 }
 228
 229 static const struct serio_device_id iforce_serio_ids[] = {
 230         {
 231                 .type   = SERIO_RS232,
 232                 .proto  = SERIO_IFORCE,
 233                 .id     = SERIO_ANY,
 234                 .extra  = SERIO_ANY,
 235         },
 236         { 0 }
 237 };
 238
 239 MODULE_DEVICE_TABLE(serio, iforce_serio_ids);
 240
 241 struct serio_driver iforce_serio_drv = {
 242         .driver         = {
 243                 .name   = "iforce",
 244         },
 245         .description    = "RS232 I-Force joysticks and wheels driver",
 246         .id_table       = iforce_serio_ids,
 247         .write_wakeup   = iforce_serio_write_wakeup,
 248         .interrupt      = iforce_serio_irq,
 249         .connect        = iforce_serio_connect,
 250         .disconnect     = iforce_serio_disconnect,
 251 };
 252
 253 module_serio_driver(iforce_serio_drv);
 254
 255 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>, Johann Deneux <johann.deneux@gmail.com>");
 256 MODULE_DESCRIPTION("RS232 I-Force joysticks and wheels driver");
 257 MODULE_LICENSE("GPL");