fsia6b.c 5.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * FS-iA6B iBus RC receiver driver
  4. *
  5. * This driver provides all 14 channels of the FlySky FS-ia6B RC receiver
  6. * as analog values.
  7. *
  8. * Additionally, the channels can be converted to discrete switch values.
  9. * By default, it is configured for the offical FS-i6 remote control.
  10. * If you use a different hardware configuration, you can configure it
  11. * using the `switch_config` parameter.
  12. */
  13. #include <linux/device.h>
  14. #include <linux/input.h>
  15. #include <linux/kernel.h>
  16. #include <linux/module.h>
  17. #include <linux/serio.h>
  18. #include <linux/slab.h>
  19. #include <linux/types.h>
  20. #define DRIVER_DESC "FS-iA6B iBus RC receiver"
  21. MODULE_AUTHOR("Markus Koch <markus@notsyncing.net>");
  22. MODULE_DESCRIPTION(DRIVER_DESC);
  23. MODULE_LICENSE("GPL");
  24. #define IBUS_SERVO_COUNT 14
  25. static char *switch_config = "00000022320000";
  26. module_param(switch_config, charp, 0444);
  27. MODULE_PARM_DESC(switch_config,
  28. "Amount of switch positions per channel (14 characters, 0-3)");
  29. static int fsia6b_axes[IBUS_SERVO_COUNT] = {
  30. ABS_X, ABS_Y,
  31. ABS_Z, ABS_RX,
  32. ABS_RY, ABS_RZ,
  33. ABS_HAT0X, ABS_HAT0Y,
  34. ABS_HAT1X, ABS_HAT1Y,
  35. ABS_HAT2X, ABS_HAT2Y,
  36. ABS_HAT3X, ABS_HAT3Y
  37. };
  38. enum ibus_state { SYNC, COLLECT, PROCESS };
  39. struct ibus_packet {
  40. enum ibus_state state;
  41. int offset;
  42. u16 ibuf;
  43. u16 channel[IBUS_SERVO_COUNT];
  44. };
  45. struct fsia6b {
  46. struct input_dev *dev;
  47. struct ibus_packet packet;
  48. char phys[32];
  49. };
  50. static irqreturn_t fsia6b_serio_irq(struct serio *serio,
  51. unsigned char data, unsigned int flags)
  52. {
  53. struct fsia6b *fsia6b = serio_get_drvdata(serio);
  54. int i;
  55. int sw_state;
  56. int sw_id = BTN_0;
  57. fsia6b->packet.ibuf = (data << 8) | ((fsia6b->packet.ibuf >> 8) & 0xFF);
  58. switch (fsia6b->packet.state) {
  59. case SYNC:
  60. if (fsia6b->packet.ibuf == 0x4020)
  61. fsia6b->packet.state = COLLECT;
  62. break;
  63. case COLLECT:
  64. fsia6b->packet.state = PROCESS;
  65. break;
  66. case PROCESS:
  67. fsia6b->packet.channel[fsia6b->packet.offset] =
  68. fsia6b->packet.ibuf;
  69. fsia6b->packet.offset++;
  70. if (fsia6b->packet.offset == IBUS_SERVO_COUNT) {
  71. fsia6b->packet.offset = 0;
  72. fsia6b->packet.state = SYNC;
  73. for (i = 0; i < IBUS_SERVO_COUNT; ++i) {
  74. input_report_abs(fsia6b->dev, fsia6b_axes[i],
  75. fsia6b->packet.channel[i]);
  76. sw_state = 0;
  77. if (fsia6b->packet.channel[i] > 1900)
  78. sw_state = 1;
  79. else if (fsia6b->packet.channel[i] < 1100)
  80. sw_state = 2;
  81. switch (switch_config[i]) {
  82. case '3':
  83. input_report_key(fsia6b->dev,
  84. sw_id++,
  85. sw_state == 0);
  86. fallthrough;
  87. case '2':
  88. input_report_key(fsia6b->dev,
  89. sw_id++,
  90. sw_state == 1);
  91. fallthrough;
  92. case '1':
  93. input_report_key(fsia6b->dev,
  94. sw_id++,
  95. sw_state == 2);
  96. }
  97. }
  98. input_sync(fsia6b->dev);
  99. } else {
  100. fsia6b->packet.state = COLLECT;
  101. }
  102. break;
  103. }
  104. return IRQ_HANDLED;
  105. }
  106. static int fsia6b_serio_connect(struct serio *serio, struct serio_driver *drv)
  107. {
  108. struct fsia6b *fsia6b;
  109. struct input_dev *input_dev;
  110. int err;
  111. int i, j;
  112. int sw_id = 0;
  113. fsia6b = kzalloc(sizeof(*fsia6b), GFP_KERNEL);
  114. if (!fsia6b)
  115. return -ENOMEM;
  116. fsia6b->packet.ibuf = 0;
  117. fsia6b->packet.offset = 0;
  118. fsia6b->packet.state = SYNC;
  119. serio_set_drvdata(serio, fsia6b);
  120. input_dev = input_allocate_device();
  121. if (!input_dev) {
  122. err = -ENOMEM;
  123. goto fail1;
  124. }
  125. fsia6b->dev = input_dev;
  126. snprintf(fsia6b->phys, sizeof(fsia6b->phys), "%s/input0", serio->phys);
  127. input_dev->name = DRIVER_DESC;
  128. input_dev->phys = fsia6b->phys;
  129. input_dev->id.bustype = BUS_RS232;
  130. input_dev->id.vendor = SERIO_FSIA6B;
  131. input_dev->id.product = serio->id.id;
  132. input_dev->id.version = 0x0100;
  133. input_dev->dev.parent = &serio->dev;
  134. for (i = 0; i < IBUS_SERVO_COUNT; i++)
  135. input_set_abs_params(input_dev, fsia6b_axes[i],
  136. 1000, 2000, 2, 2);
  137. /* Register switch configuration */
  138. for (i = 0; i < IBUS_SERVO_COUNT; i++) {
  139. if (switch_config[i] < '0' || switch_config[i] > '3') {
  140. dev_err(&fsia6b->dev->dev,
  141. "Invalid switch configuration supplied for fsia6b.\n");
  142. err = -EINVAL;
  143. goto fail2;
  144. }
  145. for (j = '1'; j <= switch_config[i]; j++) {
  146. input_set_capability(input_dev, EV_KEY, BTN_0 + sw_id);
  147. sw_id++;
  148. }
  149. }
  150. err = serio_open(serio, drv);
  151. if (err)
  152. goto fail2;
  153. err = input_register_device(fsia6b->dev);
  154. if (err)
  155. goto fail3;
  156. return 0;
  157. fail3: serio_close(serio);
  158. fail2: input_free_device(input_dev);
  159. fail1: serio_set_drvdata(serio, NULL);
  160. kfree(fsia6b);
  161. return err;
  162. }
  163. static void fsia6b_serio_disconnect(struct serio *serio)
  164. {
  165. struct fsia6b *fsia6b = serio_get_drvdata(serio);
  166. serio_close(serio);
  167. serio_set_drvdata(serio, NULL);
  168. input_unregister_device(fsia6b->dev);
  169. kfree(fsia6b);
  170. }
  171. static const struct serio_device_id fsia6b_serio_ids[] = {
  172. {
  173. .type = SERIO_RS232,
  174. .proto = SERIO_FSIA6B,
  175. .id = SERIO_ANY,
  176. .extra = SERIO_ANY,
  177. },
  178. { 0 }
  179. };
  180. MODULE_DEVICE_TABLE(serio, fsia6b_serio_ids);
  181. static struct serio_driver fsia6b_serio_drv = {
  182. .driver = {
  183. .name = "fsia6b"
  184. },
  185. .description = DRIVER_DESC,
  186. .id_table = fsia6b_serio_ids,
  187. .interrupt = fsia6b_serio_irq,
  188. .connect = fsia6b_serio_connect,
  189. .disconnect = fsia6b_serio_disconnect
  190. };
  191. module_serio_driver(fsia6b_serio_drv)