joystick/iforce/iforce-serio.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  *  Copyright (c) 2000-2001 Vojtech Pavlik <vojtech@ucw.cz>
0004  *  Copyright (c) 2001, 2007 Johann Deneux <johann.deneux@gmail.com>
0005  *
0006  *  USB/RS232 I-Force joysticks and wheels.
0007  */
0008
0009 #include <linux/serio.h>
0010 #include "iforce.h"
0011
0012 struct iforce_serio {
0013     struct iforce iforce;
0014
0015     struct serio *serio;
0016     int idx, pkt, len, id;
0017     u8 csum;
0018     u8 expect_packet;
0019     u8 cmd_response[IFORCE_MAX_LENGTH];
0020     u8 cmd_response_len;
0021     u8 data_in[IFORCE_MAX_LENGTH];
0022 };
0023
0024 static void iforce_serio_xmit(struct iforce *iforce)
0025 {
0026     struct iforce_serio *iforce_serio = container_of(iforce,
0027                              struct iforce_serio,
0028                              iforce);
0029     unsigned char cs;
0030     int i;
0031     unsigned long flags;
0032
0033     if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) {
0034         set_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags);
0035         return;
0036     }
0037
0038     spin_lock_irqsave(&iforce->xmit_lock, flags);
0039
0040 again:
0041     if (iforce->xmit.head == iforce->xmit.tail) {
0042         iforce_clear_xmit_and_wake(iforce);
0043         spin_unlock_irqrestore(&iforce->xmit_lock, flags);
0044         return;
0045     }
0046
0047     cs = 0x2b;
0048
0049     serio_write(iforce_serio->serio, 0x2b);
0050
0051     serio_write(iforce_serio->serio, iforce->xmit.buf[iforce->xmit.tail]);
0052     cs ^= iforce->xmit.buf[iforce->xmit.tail];
0053     XMIT_INC(iforce->xmit.tail, 1);
0054
0055     for (i=iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) {
0056         serio_write(iforce_serio->serio,
0057                 iforce->xmit.buf[iforce->xmit.tail]);
0058         cs ^= iforce->xmit.buf[iforce->xmit.tail];
0059         XMIT_INC(iforce->xmit.tail, 1);
0060     }
0061
0062     serio_write(iforce_serio->serio, cs);
0063
0064     if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags))
0065         goto again;
0066
0067     iforce_clear_xmit_and_wake(iforce);
0068
0069     spin_unlock_irqrestore(&iforce->xmit_lock, flags);
0070 }
0071
0072 static int iforce_serio_get_id(struct iforce *iforce, u8 id,
0073                    u8 *response_data, size_t *response_len)
0074 {
0075     struct iforce_serio *iforce_serio = container_of(iforce,
0076                              struct iforce_serio,
0077                              iforce);
0078
0079     iforce_serio->expect_packet = HI(FF_CMD_QUERY);
0080     iforce_serio->cmd_response_len = 0;
0081
0082     iforce_send_packet(iforce, FF_CMD_QUERY, &id);
0083
0084     wait_event_interruptible_timeout(iforce->wait,
0085                      !iforce_serio->expect_packet, HZ);
0086
0087     if (iforce_serio->expect_packet) {
0088         iforce_serio->expect_packet = 0;
0089         return -ETIMEDOUT;
0090     }
0091
0092     if (iforce_serio->cmd_response[0] != id)
0093         return -EIO;
0094
0095     memcpy(response_data, iforce_serio->cmd_response,
0096            iforce_serio->cmd_response_len);
0097     *response_len = iforce_serio->cmd_response_len;
0098
0099     return 0;
0100 }
0101
0102 static int iforce_serio_start_io(struct iforce *iforce)
0103 {
0104     /* No special handling required */
0105     return 0;
0106 }
0107
0108 static void iforce_serio_stop_io(struct iforce *iforce)
0109 {
0110     //TODO: Wait for the last packets to be sent
0111 }
0112
0113 static const struct iforce_xport_ops iforce_serio_xport_ops = {
0114     .xmit       = iforce_serio_xmit,
0115     .get_id     = iforce_serio_get_id,
0116     .start_io   = iforce_serio_start_io,
0117     .stop_io    = iforce_serio_stop_io,
0118 };
0119
0120 static void iforce_serio_write_wakeup(struct serio *serio)
0121 {
0122     struct iforce *iforce = serio_get_drvdata(serio);
0123
0124     iforce_serio_xmit(iforce);
0125 }
0126
0127 static irqreturn_t iforce_serio_irq(struct serio *serio,
0128                     unsigned char data, unsigned int flags)
0129 {
0130     struct iforce_serio *iforce_serio = serio_get_drvdata(serio);
0131     struct iforce *iforce = &iforce_serio->iforce;
0132
0133     if (!iforce_serio->pkt) {
0134         if (data == 0x2b)
0135             iforce_serio->pkt = 1;
0136         goto out;
0137     }
0138
0139     if (!iforce_serio->id) {
0140         if (data > 3 && data != 0xff)
0141             iforce_serio->pkt = 0;
0142         else
0143             iforce_serio->id = data;
0144         goto out;
0145     }
0146
0147     if (!iforce_serio->len) {
0148         if (data > IFORCE_MAX_LENGTH) {
0149             iforce_serio->pkt = 0;
0150             iforce_serio->id = 0;
0151         } else {
0152             iforce_serio->len = data;
0153         }
0154         goto out;
0155     }
0156
0157     if (iforce_serio->idx < iforce_serio->len) {
0158         iforce_serio->data_in[iforce_serio->idx++] = data;
0159         iforce_serio->csum += data;
0160         goto out;
0161     }
0162
0163     if (iforce_serio->idx == iforce_serio->len) {
0164         /* Handle command completion */
0165         if (iforce_serio->expect_packet == iforce_serio->id) {
0166             iforce_serio->expect_packet = 0;
0167             memcpy(iforce_serio->cmd_response,
0168                    iforce_serio->data_in, IFORCE_MAX_LENGTH);
0169             iforce_serio->cmd_response_len = iforce_serio->len;
0170
0171             /* Signal that command is done */
0172             wake_up_all(&iforce->wait);
0173         } else if (likely(iforce->type)) {
0174             iforce_process_packet(iforce, iforce_serio->id,
0175                           iforce_serio->data_in,
0176                           iforce_serio->len);
0177         }
0178
0179         iforce_serio->pkt = 0;
0180         iforce_serio->id  = 0;
0181         iforce_serio->len = 0;
0182         iforce_serio->idx = 0;
0183         iforce_serio->csum = 0;
0184     }
0185 out:
0186     return IRQ_HANDLED;
0187 }
0188
0189 static int iforce_serio_connect(struct serio *serio, struct serio_driver *drv)
0190 {
0191     struct iforce_serio *iforce_serio;
0192     int err;
0193
0194     iforce_serio = kzalloc(sizeof(*iforce_serio), GFP_KERNEL);
0195     if (!iforce_serio)
0196         return -ENOMEM;
0197
0198     iforce_serio->iforce.xport_ops = &iforce_serio_xport_ops;
0199
0200     iforce_serio->serio = serio;
0201     serio_set_drvdata(serio, iforce_serio);
0202
0203     err = serio_open(serio, drv);
0204     if (err)
0205         goto fail1;
0206
0207     err = iforce_init_device(&serio->dev, BUS_RS232, &iforce_serio->iforce);
0208     if (err)
0209         goto fail2;
0210
0211     return 0;
0212
0213  fail2: serio_close(serio);
0214  fail1: serio_set_drvdata(serio, NULL);
0215     kfree(iforce_serio);
0216     return err;
0217 }
0218
0219 static void iforce_serio_disconnect(struct serio *serio)
0220 {
0221     struct iforce_serio *iforce_serio = serio_get_drvdata(serio);
0222
0223     input_unregister_device(iforce_serio->iforce.dev);
0224     serio_close(serio);
0225     serio_set_drvdata(serio, NULL);
0226     kfree(iforce_serio);
0227 }
0228
0229 static const struct serio_device_id iforce_serio_ids[] = {
0230     {
0231         .type   = SERIO_RS232,
0232         .proto  = SERIO_IFORCE,
0233         .id = SERIO_ANY,
0234         .extra  = SERIO_ANY,
0235     },
0236     { 0 }
0237 };
0238
0239 MODULE_DEVICE_TABLE(serio, iforce_serio_ids);
0240
0241 struct serio_driver iforce_serio_drv = {
0242     .driver     = {
0243         .name   = "iforce",
0244     },
0245     .description    = "RS232 I-Force joysticks and wheels driver",
0246     .id_table   = iforce_serio_ids,
0247     .write_wakeup   = iforce_serio_write_wakeup,
0248     .interrupt  = iforce_serio_irq,
0249     .connect    = iforce_serio_connect,
0250     .disconnect = iforce_serio_disconnect,
0251 };
0252
0253 module_serio_driver(iforce_serio_drv);
0254
0255 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>, Johann Deneux <johann.deneux@gmail.com>");
0256 MODULE_DESCRIPTION("RS232 I-Force joysticks and wheels driver");
0257 MODULE_LICENSE("GPL");