Hi Heiko,
> This adds a driver for touchscreens using the zforce infrared
> technology from Neonode connected via i2c to the host system.
>
> It supports multitouch with up to two fingers and tracking of the
> contacts in hardware.
>
> Signed-off-by: Heiko Stuebner <he...@sntech.de>
Thanks for the driver. Please find some comments below.
> +static int zforce_touch_event(struct zforce_ts *ts, u8 *payload)
> +{
> + struct i2c_client *client = ts->client;
> + struct zforce_point point[ZFORCE_REPORT_POINTS];
You do not really need the array here, do you? A single member should
suffice, stack is precious.
> + const struct zforce_ts_platdata *pdata = client->dev.platform_data;
> + int count, i;
> +
> + count = payload[0];
> + if (count > ZFORCE_REPORT_POINTS) {
> + dev_warn(&client->dev, "to many coordinates %d, expected max
> %d\n",
> + count, ZFORCE_REPORT_POINTS);
> + count = ZFORCE_REPORT_POINTS;
> + }
> +
> + for (i = 0; i < count; i++) {
> + point[i].coord_x =
> + payload[9 * i + 2] << 8 | payload[9 * i + 1];
> + point[i].coord_y =
> + payload[9 * i + 4] << 8 | payload[9 * i + 3];
> +
> + if (point[i].coord_x > pdata->x_max ||
> + point[i].coord_y > pdata->y_max) {
> + dev_warn(&client->dev, "coordinates (%d,%d) invalid\n",
> + point[i].coord_x, point[i].coord_y);
> + point[i].coord_x = point[i].coord_y = 0;
> + }
> +
> + point[i].state = payload[9 * i + 5] & 0x03;
> + point[i].id = (payload[9 * i + 5] & 0xfc) >> 2;
> +
> + /* determine touch major, minor and orientation */
> + point[i].area_major = max(payload[9 * i + 6],
> + payload[9 * i + 7]);
> + point[i].area_minor = min(payload[9 * i + 6],
> + payload[9 * i + 7]);
> + point[i].orientation = payload[9 * i + 6] > payload[9 * i + 7];
> +
> + point[i].pressure = payload[9 * i + 8];
> + point[i].prblty = payload[9 * i + 9];
> + }
> +
> + for (i = 0; i < count; i++) {
just continue the loop here (or move the conversion out as a function).
> + dev_dbg(&client->dev, "point %d/%d: state %d, id %d, pressure
> %d, prblty %d, x %d, y %d, amajor %d, aminor %d, ori %d\n",
> + i, count, point[i].state, point[i].id,
> + point[i].pressure, point[i].prblty,
> + point[i].coord_x, point[i].coord_y,
> + point[i].area_major, point[i].area_minor,
> + point[i].orientation);
> +
> + /* the zforce id starts with "1", so needs to be decreased */
> + input_mt_slot(ts->input, point[i].id - 1);
> +
> + input_mt_report_slot_state(ts->input, MT_TOOL_FINGER,
> + point[i].state != STATE_UP);
> +
> + if (point[i].state != STATE_UP) {
> + input_report_abs(ts->input, ABS_MT_POSITION_X,
> + point[i].coord_x);
> + input_report_abs(ts->input, ABS_MT_POSITION_Y,
> + point[i].coord_y);
> + input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
> + point[i].area_major);
> + input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
> + point[i].area_minor);
> + input_report_abs(ts->input, ABS_MT_ORIENTATION,
> + point[i].orientation);
> + }
> + }
> +
> + if (point[0].state != STATE_UP) {
> + input_report_abs(ts->input, ABS_X, point[0].coord_x);
> + input_report_abs(ts->input, ABS_Y, point[0].coord_y);
> + }
> +
> + input_report_key(ts->input, BTN_TOUCH, point[0].state != STATE_UP);
You can use input_mt_sync() here instead of the single-touch stuff.
> +
> + input_sync(ts->input);
> +
> + return 0;
> +}
> +
> +static int zforce_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + const struct zforce_ts_platdata *pdata = client->dev.platform_data;
> + struct zforce_ts *ts;
> + struct input_dev *input_dev;
> + int ret;
> +
> + if (!pdata)
> + return -EINVAL;
> +
> + ts = devm_kzalloc(&client->dev, sizeof(struct zforce_ts), GFP_KERNEL);
> + if (!ts)
> + return -ENOMEM;
> +
> + ret = devm_gpio_request_one(&client->dev, pdata->gpio_int, GPIOF_IN,
> + "zforce_ts_int");
> + if (ret) {
> + dev_err(&client->dev, "request of gpio %d failed, %d\n",
> + pdata->gpio_int, ret);
> + return ret;
> + }
> +
> + ret = devm_gpio_request_one(&client->dev, pdata->gpio_rst,
> + GPIOF_OUT_INIT_LOW, "zforce_ts_rst");
> + if (ret) {
> + dev_err(&client->dev, "request of gpio %d failed, %d\n",
> + pdata->gpio_rst, ret);
> + return ret;
> + }
> +
> + ret = devm_add_action(&client->dev, zforce_reset, ts);
> + if (ret) {
> + dev_err(&client->dev, "failed to register reset action, %d\n",
> + ret);
> + return ret;
> + }
> +
> + msleep(20);
> +
> + snprintf(ts->phys, sizeof(ts->phys),
> + "%s/input0", dev_name(&client->dev));
> +
> + input_dev = devm_input_allocate_device(&client->dev);
> + if (!input_dev) {
> + dev_err(&client->dev, "could not allocate input device\n");
> + return -ENOMEM;
> + }
> +
> + mutex_init(&ts->access_mutex);
> + mutex_init(&ts->command_mutex);
> +
> + ts->pdata = pdata;
> + ts->client = client;
> + ts->input = input_dev;
> +
> + input_dev->name = "Neonode zForce touchscreen";
> + input_dev->phys = ts->phys;
> + input_dev->id.bustype = BUS_I2C;
> + input_dev->dev.parent = &client->dev;
> +
> + input_dev->open = zforce_input_open;
> + input_dev->close = zforce_input_close;
> +
> + set_bit(EV_KEY, input_dev->evbit);
> + set_bit(EV_SYN, input_dev->evbit);
> + set_bit(EV_ABS, input_dev->evbit);
> + set_bit(BTN_TOUCH, input_dev->keybit);
BTN_TOUCH can be skipped,
> +
> + /* For single touch */
> + input_set_abs_params(input_dev, ABS_X, 0, pdata->x_max, 0, 0);
> + input_set_abs_params(input_dev, ABS_Y, 0, pdata->y_max, 0, 0);
and these too,
> +
> + /* For multi touch */
> + input_mt_init_slots(input_dev, ZFORCE_REPORT_POINTS, 0);
if you add INPUT_MT_DIRECT as argument here.
> + input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0,
> + pdata->x_max, 0, 0);
> + input_set_abs_params(input_dev, ABS_MT_POSITION_Y, 0,
> + pdata->y_max, 0, 0);
> +
> + input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
> + ZFORCE_MAX_AREA, 0, 0);
> + input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, 0,
> + ZFORCE_MAX_AREA, 0, 0);
> + input_set_abs_params(input_dev, ABS_MT_ORIENTATION, 0, 1, 0, 0);
> +
> + input_set_drvdata(ts->input, ts);
> +
> + init_completion(&ts->command_done);
> +
> + /* The zforce pulls the interrupt low when it has data ready.
> + * After it is triggered the isr thread runs until all the available
> + * packets have been read and the interrupt is high again.
> + * Therefore we can trigger the interrupt anytime it is low and do
> + * not need to limit it to the interrupt edge.
> + */
> + ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> + zforce_interrupt,
> + IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> + input_dev->name, ts);
> + if (ret) {
> + dev_err(&client->dev, "irq %d request failed\n", client->irq);
> + return ret;
> + }
> +
> + i2c_set_clientdata(client, ts);
> +
> + /* let the controller boot */
> + gpio_set_value(pdata->gpio_rst, 1);
> +
> + ts->command_waiting = NOTIFICATION_BOOTCOMPLETE;
> + if (wait_for_completion_timeout(&ts->command_done, WAIT_TIMEOUT) == 0)
> + dev_warn(&client->dev, "bootcomplete timed out\n");
> +
> + /* need to start device to get version information */
> + ret = zforce_command_wait(ts, COMMAND_INITIALIZE);
> + if (ret) {
> + dev_err(&client->dev, "unable to initialize, %d\n", ret);
> + return ret;
> + }
> +
> + /* this gets the firmware version among other informations */
> + ret = zforce_command_wait(ts, COMMAND_STATUS);
> + if (ret < 0) {
> + dev_err(&client->dev, "couldn't get status, %d\n", ret);
> + zforce_stop(ts);
> + return ret;
> + }
> +
> + /* stop device and put it into sleep until it is opened */
> + ret = zforce_stop(ts);
> + if (ret < 0)
> + return ret;
> +
> + device_set_wakeup_capable(&client->dev, true);
> +
> + ret = input_register_device(input_dev);
> + if (ret) {
> + dev_err(&client->dev, "could not register input device, %d\n",
> + ret);
> + return ret;
> + }
> +
> + return 0;
> +}
Thanks,
Henrik
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