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d99caa472c
gpiod API allows standard way of specifying GPIO polarity and takes it into account when reading or setting GPIO state. It also allows us to switch to common way of obtaining GPIO descriptor and away form legacy platform data. Reviewed-by: Daniel Mack <daniel@zonque.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
279 lines
6.6 KiB
C
279 lines
6.6 KiB
C
/*
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* Touch Screen driver for EETI's I2C connected touch screen panels
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* Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
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*
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* See EETI's software guide for the protocol specification:
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* http://home.eeti.com.tw/web20/eg/guide.htm
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*
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* Based on migor_ts.c
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* Copyright (c) 2008 Magnus Damm
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* Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>
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*
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* This file is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This file is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/kernel.h>
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#include <linux/input.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/timer.h>
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#include <linux/gpio/consumer.h>
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#include <linux/slab.h>
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#include <asm/unaligned.h>
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static bool flip_x;
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module_param(flip_x, bool, 0644);
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MODULE_PARM_DESC(flip_x, "flip x coordinate");
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static bool flip_y;
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module_param(flip_y, bool, 0644);
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MODULE_PARM_DESC(flip_y, "flip y coordinate");
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struct eeti_ts {
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struct i2c_client *client;
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struct input_dev *input;
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struct gpio_desc *attn_gpio;
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bool running;
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};
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#define EETI_TS_BITDEPTH (11)
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#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1)
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#define REPORT_BIT_PRESSED BIT(0)
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#define REPORT_BIT_AD0 BIT(1)
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#define REPORT_BIT_AD1 BIT(2)
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#define REPORT_BIT_HAS_PRESSURE BIT(6)
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#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
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static void eeti_ts_report_event(struct eeti_ts *eeti, u8 *buf)
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{
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unsigned int res;
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u16 x, y;
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res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
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x = get_unaligned_be16(&buf[1]);
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y = get_unaligned_be16(&buf[3]);
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/* fix the range to 11 bits */
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x >>= res - EETI_TS_BITDEPTH;
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y >>= res - EETI_TS_BITDEPTH;
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if (flip_x)
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x = EETI_MAXVAL - x;
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if (flip_y)
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y = EETI_MAXVAL - y;
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if (buf[0] & REPORT_BIT_HAS_PRESSURE)
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input_report_abs(eeti->input, ABS_PRESSURE, buf[5]);
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input_report_abs(eeti->input, ABS_X, x);
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input_report_abs(eeti->input, ABS_Y, y);
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input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED);
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input_sync(eeti->input);
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}
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static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
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{
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struct eeti_ts *eeti = dev_id;
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int len;
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int error;
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char buf[6];
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do {
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len = i2c_master_recv(eeti->client, buf, sizeof(buf));
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if (len != sizeof(buf)) {
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error = len < 0 ? len : -EIO;
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dev_err(&eeti->client->dev,
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"failed to read touchscreen data: %d\n",
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error);
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break;
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}
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if (buf[0] & 0x80) {
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/* Motion packet */
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eeti_ts_report_event(eeti, buf);
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}
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} while (eeti->running &&
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eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio));
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return IRQ_HANDLED;
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}
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static void eeti_ts_start(struct eeti_ts *eeti)
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{
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eeti->running = true;
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wmb();
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enable_irq(eeti->client->irq);
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}
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static void eeti_ts_stop(struct eeti_ts *eeti)
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{
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eeti->running = false;
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wmb();
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disable_irq(eeti->client->irq);
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}
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static int eeti_ts_open(struct input_dev *dev)
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{
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struct eeti_ts *eeti = input_get_drvdata(dev);
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eeti_ts_start(eeti);
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return 0;
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}
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static void eeti_ts_close(struct input_dev *dev)
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{
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struct eeti_ts *eeti = input_get_drvdata(dev);
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eeti_ts_stop(eeti);
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}
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static int eeti_ts_probe(struct i2c_client *client,
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const struct i2c_device_id *idp)
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{
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struct device *dev = &client->dev;
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struct eeti_ts *eeti;
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struct input_dev *input;
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int error;
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/*
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* In contrast to what's described in the datasheet, there seems
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* to be no way of probing the presence of that device using I2C
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* commands. So we need to blindly believe it is there, and wait
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* for interrupts to occur.
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*/
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eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL);
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if (!eeti) {
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dev_err(dev, "failed to allocate driver data\n");
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return -ENOMEM;
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}
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input = devm_input_allocate_device(dev);
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if (!input) {
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dev_err(dev, "Failed to allocate input device.\n");
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return -ENOMEM;
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}
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input_set_capability(input, EV_KEY, BTN_TOUCH);
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input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
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input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
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input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);
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input->name = client->name;
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input->id.bustype = BUS_I2C;
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input->open = eeti_ts_open;
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input->close = eeti_ts_close;
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eeti->client = client;
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eeti->input = input;
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eeti->attn_gpio = devm_gpiod_get_optional(dev, "attn", GPIOD_IN);
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if (IS_ERR(eeti->attn_gpio))
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return PTR_ERR(eeti->attn_gpio);
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i2c_set_clientdata(client, eeti);
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input_set_drvdata(input, eeti);
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error = devm_request_threaded_irq(dev, client->irq,
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NULL, eeti_ts_isr,
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IRQF_ONESHOT,
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client->name, eeti);
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if (error) {
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dev_err(dev, "Unable to request touchscreen IRQ: %d\n",
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error);
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return error;
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}
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/*
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* Disable the device for now. It will be enabled once the
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* input device is opened.
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*/
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eeti_ts_stop(eeti);
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error = input_register_device(input);
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if (error)
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return error;
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return 0;
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}
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static int __maybe_unused eeti_ts_suspend(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct eeti_ts *eeti = i2c_get_clientdata(client);
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struct input_dev *input_dev = eeti->input;
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mutex_lock(&input_dev->mutex);
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if (input_dev->users)
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eeti_ts_stop(eeti);
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mutex_unlock(&input_dev->mutex);
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if (device_may_wakeup(&client->dev))
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enable_irq_wake(client->irq);
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return 0;
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}
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static int __maybe_unused eeti_ts_resume(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct eeti_ts *eeti = i2c_get_clientdata(client);
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struct input_dev *input_dev = eeti->input;
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if (device_may_wakeup(&client->dev))
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disable_irq_wake(client->irq);
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mutex_lock(&input_dev->mutex);
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if (input_dev->users)
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eeti_ts_start(eeti);
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mutex_unlock(&input_dev->mutex);
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
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static const struct i2c_device_id eeti_ts_id[] = {
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{ "eeti_ts", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
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static struct i2c_driver eeti_ts_driver = {
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.driver = {
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.name = "eeti_ts",
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.pm = &eeti_ts_pm,
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},
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.probe = eeti_ts_probe,
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.id_table = eeti_ts_id,
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};
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module_i2c_driver(eeti_ts_driver);
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MODULE_DESCRIPTION("EETI Touchscreen driver");
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MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
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MODULE_LICENSE("GPL");
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