/* * Touch Screen driver for EETI's I2C connected touch screen panels * Copyright (c) 2009 Daniel Mack * * See EETI's software guide for the protocol specification: * http://home.eeti.com.tw/web20/eg/guide.htm * * Based on migor_ts.c * Copyright (c) 2008 Magnus Damm * Copyright (c) 2007 Ujjwal Pande * * This file is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This file is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include #include #include #include #include #include #include #include static bool flip_x; module_param(flip_x, bool, 0644); MODULE_PARM_DESC(flip_x, "flip x coordinate"); static bool flip_y; module_param(flip_y, bool, 0644); MODULE_PARM_DESC(flip_y, "flip y coordinate"); struct eeti_ts { struct i2c_client *client; struct input_dev *input; struct work_struct work; struct mutex mutex; int irq_gpio, irq_active_high; }; #define EETI_TS_BITDEPTH (11) #define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1) #define REPORT_BIT_PRESSED BIT(0) #define REPORT_BIT_AD0 BIT(1) #define REPORT_BIT_AD1 BIT(2) #define REPORT_BIT_HAS_PRESSURE BIT(6) #define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH) static inline int eeti_ts_irq_active(struct eeti_ts *eeti) { return gpio_get_value_cansleep(eeti->irq_gpio) == eeti->irq_active_high; } static void eeti_ts_read(struct work_struct *work) { char buf[6]; unsigned int x, y, res, pressed, to = 100; struct eeti_ts *eeti = container_of(work, struct eeti_ts, work); mutex_lock(&eeti->mutex); while (eeti_ts_irq_active(eeti) && --to) i2c_master_recv(eeti->client, buf, sizeof(buf)); if (!to) { dev_err(&eeti->client->dev, "unable to clear IRQ - line stuck?\n"); goto out; } /* drop non-report packets */ if (!(buf[0] & 0x80)) goto out; pressed = buf[0] & REPORT_BIT_PRESSED; res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1)); x = get_unaligned_be16(&buf[1]); y = get_unaligned_be16(&buf[3]); /* fix the range to 11 bits */ x >>= res - EETI_TS_BITDEPTH; y >>= res - EETI_TS_BITDEPTH; if (flip_x) x = EETI_MAXVAL - x; if (flip_y) y = EETI_MAXVAL - y; if (buf[0] & REPORT_BIT_HAS_PRESSURE) input_report_abs(eeti->input, ABS_PRESSURE, buf[5]); input_report_abs(eeti->input, ABS_X, x); input_report_abs(eeti->input, ABS_Y, y); input_report_key(eeti->input, BTN_TOUCH, !!pressed); input_sync(eeti->input); out: mutex_unlock(&eeti->mutex); } static irqreturn_t eeti_ts_isr(int irq, void *dev_id) { struct eeti_ts *eeti = dev_id; /* postpone I2C transactions as we are atomic */ schedule_work(&eeti->work); return IRQ_HANDLED; } static void eeti_ts_start(struct eeti_ts *eeti) { enable_irq(eeti->client->irq); /* Read the events once to arm the IRQ */ eeti_ts_read(&eeti->work); } static void eeti_ts_stop(struct eeti_ts *eeti) { disable_irq(eeti->client->irq); cancel_work_sync(&eeti->work); } static int eeti_ts_open(struct input_dev *dev) { struct eeti_ts *eeti = input_get_drvdata(dev); eeti_ts_start(eeti); return 0; } static void eeti_ts_close(struct input_dev *dev) { struct eeti_ts *eeti = input_get_drvdata(dev); eeti_ts_stop(eeti); } static int eeti_ts_probe(struct i2c_client *client, const struct i2c_device_id *idp) { struct device *dev = &client->dev; struct eeti_ts_platform_data *pdata = dev_get_platdata(dev); struct eeti_ts *eeti; struct input_dev *input; unsigned int irq_flags; int error; /* * In contrast to what's described in the datasheet, there seems * to be no way of probing the presence of that device using I2C * commands. So we need to blindly believe it is there, and wait * for interrupts to occur. */ eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL); if (!eeti) { dev_err(dev, "failed to allocate driver data\n"); return -ENOMEM; } mutex_init(&eeti->mutex); input = devm_input_allocate_device(dev); if (!input) { dev_err(dev, "Failed to allocate input device.\n"); return -ENOMEM; } input_set_capability(input, EV_KEY, BTN_TOUCH); input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0); input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0); input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0); input->name = client->name; input->id.bustype = BUS_I2C; input->open = eeti_ts_open; input->close = eeti_ts_close; eeti->client = client; eeti->input = input; eeti->irq_gpio = pdata->irq_gpio; error = devm_gpio_request_one(dev, pdata->irq_gpio, GPIOF_IN, client->name); if (error) return error; eeti->irq_active_high = pdata->irq_active_high; irq_flags = eeti->irq_active_high ? IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; INIT_WORK(&eeti->work, eeti_ts_read); i2c_set_clientdata(client, eeti); input_set_drvdata(input, eeti); error = input_register_device(input); if (error) return error; error = devm_request_irq(dev, client->irq, eeti_ts_isr, irq_flags, client->name, eeti); if (error) { dev_err(dev, "Unable to request touchscreen IRQ: %d\n", error); return error; } /* * Disable the device for now. It will be enabled once the * input device is opened. */ eeti_ts_stop(eeti); return 0; } static int __maybe_unused eeti_ts_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct eeti_ts *eeti = i2c_get_clientdata(client); struct input_dev *input_dev = eeti->input; mutex_lock(&input_dev->mutex); if (input_dev->users) eeti_ts_stop(eeti); mutex_unlock(&input_dev->mutex); if (device_may_wakeup(&client->dev)) enable_irq_wake(client->irq); return 0; } static int __maybe_unused eeti_ts_resume(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct eeti_ts *eeti = i2c_get_clientdata(client); struct input_dev *input_dev = eeti->input; if (device_may_wakeup(&client->dev)) disable_irq_wake(client->irq); mutex_lock(&input_dev->mutex); if (input_dev->users) eeti_ts_start(eeti); mutex_unlock(&input_dev->mutex); return 0; } static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume); static const struct i2c_device_id eeti_ts_id[] = { { "eeti_ts", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, eeti_ts_id); static struct i2c_driver eeti_ts_driver = { .driver = { .name = "eeti_ts", .pm = &eeti_ts_pm, }, .probe = eeti_ts_probe, .id_table = eeti_ts_id, }; module_i2c_driver(eeti_ts_driver); MODULE_DESCRIPTION("EETI Touchscreen driver"); MODULE_AUTHOR("Daniel Mack "); MODULE_LICENSE("GPL");