input/mouse/focaltech.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Focaltech TouchPad PS/2 mouse driver
0004  *
0005  * Copyright (c) 2014 Red Hat Inc.
0006  * Copyright (c) 2014 Mathias Gottschlag <mgottschlag@gmail.com>
0007  *
0008  * Red Hat authors:
0009  *
0010  * Hans de Goede <hdegoede@redhat.com>
0011  */
0012
0013
0014 #include <linux/device.h>
0015 #include <linux/libps2.h>
0016 #include <linux/input/mt.h>
0017 #include <linux/serio.h>
0018 #include <linux/slab.h>
0019 #include "psmouse.h"
0020 #include "focaltech.h"
0021
0022 static const char * const focaltech_pnp_ids[] = {
0023     "FLT0101",
0024     "FLT0102",
0025     "FLT0103",
0026     NULL
0027 };
0028
0029 /*
0030  * Even if the kernel is built without support for Focaltech PS/2 touchpads (or
0031  * when the real driver fails to recognize the device), we still have to detect
0032  * them in order to avoid further detection attempts confusing the touchpad.
0033  * This way it at least works in PS/2 mouse compatibility mode.
0034  */
0035 int focaltech_detect(struct psmouse *psmouse, bool set_properties)
0036 {
0037     if (!psmouse_matches_pnp_id(psmouse, focaltech_pnp_ids))
0038         return -ENODEV;
0039
0040     if (set_properties) {
0041         psmouse->vendor = "FocalTech";
0042         psmouse->name = "Touchpad";
0043     }
0044
0045     return 0;
0046 }
0047
0048 #ifdef CONFIG_MOUSE_PS2_FOCALTECH
0049
0050 /*
0051  * Packet types - the numbers are not consecutive, so we might be missing
0052  * something here.
0053  */
0054 #define FOC_TOUCH 0x3 /* bitmap of active fingers */
0055 #define FOC_ABS 0x6 /* absolute position of one finger */
0056 #define FOC_REL 0x9 /* relative position of 1-2 fingers */
0057
0058 #define FOC_MAX_FINGERS 5
0059
0060 /*
0061  * Current state of a single finger on the touchpad.
0062  */
0063 struct focaltech_finger_state {
0064     /* The touchpad has generated a touch event for the finger */
0065     bool active;
0066
0067     /*
0068      * The touchpad has sent position data for the finger. The
0069      * flag is 0 when the finger is not active, and there is a
0070      * time between the first touch event for the finger and the
0071      * following absolute position packet for the finger where the
0072      * touchpad has declared the finger to be valid, but we do not
0073      * have any valid position yet.
0074      */
0075     bool valid;
0076
0077     /*
0078      * Absolute position (from the bottom left corner) of the
0079      * finger.
0080      */
0081     unsigned int x;
0082     unsigned int y;
0083 };
0084
0085 /*
0086  * Description of the current state of the touchpad hardware.
0087  */
0088 struct focaltech_hw_state {
0089     /*
0090      * The touchpad tracks the positions of the fingers for us,
0091      * the array indices correspond to the finger indices returned
0092      * in the report packages.
0093      */
0094     struct focaltech_finger_state fingers[FOC_MAX_FINGERS];
0095
0096     /*
0097      * Finger width 0-7 and 15 for a very big contact area.
0098      * 15 value stays until the finger is released.
0099      * Width is reported only in absolute packets.
0100      * Since hardware reports width only for last touching finger,
0101      * there is no need to store width for every specific finger,
0102      * so we keep only last value reported.
0103      */
0104     unsigned int width;
0105
0106     /* True if the clickpad has been pressed. */
0107     bool pressed;
0108 };
0109
0110 struct focaltech_data {
0111     unsigned int x_max, y_max;
0112     struct focaltech_hw_state state;
0113 };
0114
0115 static void focaltech_report_state(struct psmouse *psmouse)
0116 {
0117     struct focaltech_data *priv = psmouse->private;
0118     struct focaltech_hw_state *state = &priv->state;
0119     struct input_dev *dev = psmouse->dev;
0120     int i;
0121
0122     for (i = 0; i < FOC_MAX_FINGERS; i++) {
0123         struct focaltech_finger_state *finger = &state->fingers[i];
0124         bool active = finger->active && finger->valid;
0125
0126         input_mt_slot(dev, i);
0127         input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
0128         if (active) {
0129             unsigned int clamped_x, clamped_y;
0130             /*
0131              * The touchpad might report invalid data, so we clamp
0132              * the resulting values so that we do not confuse
0133              * userspace.
0134              */
0135             clamped_x = clamp(finger->x, 0U, priv->x_max);
0136             clamped_y = clamp(finger->y, 0U, priv->y_max);
0137             input_report_abs(dev, ABS_MT_POSITION_X, clamped_x);
0138             input_report_abs(dev, ABS_MT_POSITION_Y,
0139                      priv->y_max - clamped_y);
0140             input_report_abs(dev, ABS_TOOL_WIDTH, state->width);
0141         }
0142     }
0143     input_mt_report_pointer_emulation(dev, true);
0144
0145     input_report_key(dev, BTN_LEFT, state->pressed);
0146     input_sync(dev);
0147 }
0148
0149 static void focaltech_process_touch_packet(struct psmouse *psmouse,
0150                        unsigned char *packet)
0151 {
0152     struct focaltech_data *priv = psmouse->private;
0153     struct focaltech_hw_state *state = &priv->state;
0154     unsigned char fingers = packet[1];
0155     int i;
0156
0157     state->pressed = (packet[0] >> 4) & 1;
0158
0159     /* the second byte contains a bitmap of all fingers touching the pad */
0160     for (i = 0; i < FOC_MAX_FINGERS; i++) {
0161         state->fingers[i].active = fingers & 0x1;
0162         if (!state->fingers[i].active) {
0163             /*
0164              * Even when the finger becomes active again, we still
0165              * will have to wait for the first valid position.
0166              */
0167             state->fingers[i].valid = false;
0168         }
0169         fingers >>= 1;
0170     }
0171 }
0172
0173 static void focaltech_process_abs_packet(struct psmouse *psmouse,
0174                      unsigned char *packet)
0175 {
0176     struct focaltech_data *priv = psmouse->private;
0177     struct focaltech_hw_state *state = &priv->state;
0178     unsigned int finger;
0179
0180     finger = (packet[1] >> 4) - 1;
0181     if (finger >= FOC_MAX_FINGERS) {
0182         psmouse_err(psmouse, "Invalid finger in abs packet: %d\n",
0183                 finger);
0184         return;
0185     }
0186
0187     state->pressed = (packet[0] >> 4) & 1;
0188
0189     state->fingers[finger].x = ((packet[1] & 0xf) << 8) | packet[2];
0190     state->fingers[finger].y = (packet[3] << 8) | packet[4];
0191     state->width = packet[5] >> 4;
0192     state->fingers[finger].valid = true;
0193 }
0194
0195 static void focaltech_process_rel_packet(struct psmouse *psmouse,
0196                      unsigned char *packet)
0197 {
0198     struct focaltech_data *priv = psmouse->private;
0199     struct focaltech_hw_state *state = &priv->state;
0200     int finger1, finger2;
0201
0202     state->pressed = packet[0] >> 7;
0203     finger1 = ((packet[0] >> 4) & 0x7) - 1;
0204     if (finger1 < FOC_MAX_FINGERS) {
0205         state->fingers[finger1].x += (char)packet[1];
0206         state->fingers[finger1].y += (char)packet[2];
0207     } else {
0208         psmouse_err(psmouse, "First finger in rel packet invalid: %d\n",
0209                 finger1);
0210     }
0211
0212     /*
0213      * If there is an odd number of fingers, the last relative
0214      * packet only contains one finger. In this case, the second
0215      * finger index in the packet is 0 (we subtract 1 in the lines
0216      * above to create array indices, so the finger will overflow
0217      * and be above FOC_MAX_FINGERS).
0218      */
0219     finger2 = ((packet[3] >> 4) & 0x7) - 1;
0220     if (finger2 < FOC_MAX_FINGERS) {
0221         state->fingers[finger2].x += (char)packet[4];
0222         state->fingers[finger2].y += (char)packet[5];
0223     }
0224 }
0225
0226 static void focaltech_process_packet(struct psmouse *psmouse)
0227 {
0228     unsigned char *packet = psmouse->packet;
0229
0230     switch (packet[0] & 0xf) {
0231     case FOC_TOUCH:
0232         focaltech_process_touch_packet(psmouse, packet);
0233         break;
0234
0235     case FOC_ABS:
0236         focaltech_process_abs_packet(psmouse, packet);
0237         break;
0238
0239     case FOC_REL:
0240         focaltech_process_rel_packet(psmouse, packet);
0241         break;
0242
0243     default:
0244         psmouse_err(psmouse, "Unknown packet type: %02x\n", packet[0]);
0245         break;
0246     }
0247
0248     focaltech_report_state(psmouse);
0249 }
0250
0251 static psmouse_ret_t focaltech_process_byte(struct psmouse *psmouse)
0252 {
0253     if (psmouse->pktcnt >= 6) { /* Full packet received */
0254         focaltech_process_packet(psmouse);
0255         return PSMOUSE_FULL_PACKET;
0256     }
0257
0258     /*
0259      * We might want to do some validation of the data here, but
0260      * we do not know the protocol well enough
0261      */
0262     return PSMOUSE_GOOD_DATA;
0263 }
0264
0265 static int focaltech_switch_protocol(struct psmouse *psmouse)
0266 {
0267     struct ps2dev *ps2dev = &psmouse->ps2dev;
0268     unsigned char param[3];
0269
0270     param[0] = 0;
0271     if (ps2_command(ps2dev, param, 0x10f8))
0272         return -EIO;
0273
0274     if (ps2_command(ps2dev, param, 0x10f8))
0275         return -EIO;
0276
0277     if (ps2_command(ps2dev, param, 0x10f8))
0278         return -EIO;
0279
0280     param[0] = 1;
0281     if (ps2_command(ps2dev, param, 0x10f8))
0282         return -EIO;
0283
0284     if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
0285         return -EIO;
0286
0287     if (ps2_command(ps2dev, param, PSMOUSE_CMD_ENABLE))
0288         return -EIO;
0289
0290     return 0;
0291 }
0292
0293 static void focaltech_reset(struct psmouse *psmouse)
0294 {
0295     ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_RESET_DIS);
0296     psmouse_reset(psmouse);
0297 }
0298
0299 static void focaltech_disconnect(struct psmouse *psmouse)
0300 {
0301     focaltech_reset(psmouse);
0302     kfree(psmouse->private);
0303     psmouse->private = NULL;
0304 }
0305
0306 static int focaltech_reconnect(struct psmouse *psmouse)
0307 {
0308     int error;
0309
0310     focaltech_reset(psmouse);
0311
0312     error = focaltech_switch_protocol(psmouse);
0313     if (error) {
0314         psmouse_err(psmouse, "Unable to initialize the device\n");
0315         return error;
0316     }
0317
0318     return 0;
0319 }
0320
0321 static void focaltech_set_input_params(struct psmouse *psmouse)
0322 {
0323     struct input_dev *dev = psmouse->dev;
0324     struct focaltech_data *priv = psmouse->private;
0325
0326     /*
0327      * Undo part of setup done for us by psmouse core since touchpad
0328      * is not a relative device.
0329      */
0330     __clear_bit(EV_REL, dev->evbit);
0331     __clear_bit(REL_X, dev->relbit);
0332     __clear_bit(REL_Y, dev->relbit);
0333     __clear_bit(BTN_RIGHT, dev->keybit);
0334     __clear_bit(BTN_MIDDLE, dev->keybit);
0335
0336     /*
0337      * Now set up our capabilities.
0338      */
0339     __set_bit(EV_ABS, dev->evbit);
0340     input_set_abs_params(dev, ABS_MT_POSITION_X, 0, priv->x_max, 0, 0);
0341     input_set_abs_params(dev, ABS_MT_POSITION_Y, 0, priv->y_max, 0, 0);
0342     input_set_abs_params(dev, ABS_TOOL_WIDTH, 0, 15, 0, 0);
0343     input_mt_init_slots(dev, 5, INPUT_MT_POINTER);
0344     __set_bit(INPUT_PROP_BUTTONPAD, dev->propbit);
0345 }
0346
0347 static int focaltech_read_register(struct ps2dev *ps2dev, int reg,
0348                    unsigned char *param)
0349 {
0350     if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETSCALE11))
0351         return -EIO;
0352
0353     param[0] = 0;
0354     if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
0355         return -EIO;
0356
0357     if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
0358         return -EIO;
0359
0360     if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
0361         return -EIO;
0362
0363     param[0] = reg;
0364     if (ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES))
0365         return -EIO;
0366
0367     if (ps2_command(ps2dev, param, PSMOUSE_CMD_GETINFO))
0368         return -EIO;
0369
0370     return 0;
0371 }
0372
0373 static int focaltech_read_size(struct psmouse *psmouse)
0374 {
0375     struct ps2dev *ps2dev = &psmouse->ps2dev;
0376     struct focaltech_data *priv = psmouse->private;
0377     char param[3];
0378
0379     if (focaltech_read_register(ps2dev, 2, param))
0380         return -EIO;
0381
0382     /* not sure whether this is 100% correct */
0383     priv->x_max = (unsigned char)param[1] * 128;
0384     priv->y_max = (unsigned char)param[2] * 128;
0385
0386     return 0;
0387 }
0388
0389 static void focaltech_set_resolution(struct psmouse *psmouse,
0390                      unsigned int resolution)
0391 {
0392     /* not supported yet */
0393 }
0394
0395 static void focaltech_set_rate(struct psmouse *psmouse, unsigned int rate)
0396 {
0397     /* not supported yet */
0398 }
0399
0400 static void focaltech_set_scale(struct psmouse *psmouse,
0401                 enum psmouse_scale scale)
0402 {
0403     /* not supported yet */
0404 }
0405
0406 int focaltech_init(struct psmouse *psmouse)
0407 {
0408     struct focaltech_data *priv;
0409     int error;
0410
0411     psmouse->private = priv = kzalloc(sizeof(struct focaltech_data),
0412                       GFP_KERNEL);
0413     if (!priv)
0414         return -ENOMEM;
0415
0416     focaltech_reset(psmouse);
0417
0418     error = focaltech_read_size(psmouse);
0419     if (error) {
0420         psmouse_err(psmouse,
0421                 "Unable to read the size of the touchpad\n");
0422         goto fail;
0423     }
0424
0425     error = focaltech_switch_protocol(psmouse);
0426     if (error) {
0427         psmouse_err(psmouse, "Unable to initialize the device\n");
0428         goto fail;
0429     }
0430
0431     focaltech_set_input_params(psmouse);
0432
0433     psmouse->protocol_handler = focaltech_process_byte;
0434     psmouse->pktsize = 6;
0435     psmouse->disconnect = focaltech_disconnect;
0436     psmouse->reconnect = focaltech_reconnect;
0437     psmouse->cleanup = focaltech_reset;
0438     /* resync is not supported yet */
0439     psmouse->resync_time = 0;
0440     /*
0441      * rate/resolution/scale changes are not supported yet, and
0442      * the generic implementations of these functions seem to
0443      * confuse some touchpads
0444      */
0445     psmouse->set_resolution = focaltech_set_resolution;
0446     psmouse->set_rate = focaltech_set_rate;
0447     psmouse->set_scale = focaltech_set_scale;
0448
0449     return 0;
0450
0451 fail:
0452     focaltech_reset(psmouse);
0453     kfree(priv);
0454     return error;
0455 }
0456 #endif /* CONFIG_MOUSE_PS2_FOCALTECH */