![Arnd Bergmann](/assets/img/avatar_default.png)
The EETI touchscreen asserts its IRQ line as soon as it has data in its internal buffers. The line is automatically deasserted once all data has been read via I2C. Hence, the driver has to monitor the GPIO line and cannot simply rely on the interrupt handler reception. In the current implementation of the driver, irq_to_gpio() is used to determine the GPIO number from the i2c_client's IRQ value. As irq_to_gpio() is not available on all platforms, this patch changes this and makes the driver ignore the passed in IRQ. Instead, a GPIO is added to the platform_data struct and gpio_to_irq is used to derive the IRQ from that GPIO. If this fails, bail out. The driver is only able to work in environments where the touchscreen GPIO can be mapped to an IRQ. Without this patch, building raumfeld_defconfig results in: drivers/input/touchscreen/eeti_ts.c: In function 'eeti_ts_irq_active': drivers/input/touchscreen/eeti_ts.c:65:2: error: implicit declaration of function 'irq_to_gpio' [-Werror=implicit-function-declaration] Signed-off-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: stable@vger.kernel.org (v3.2+) Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Sven Neumann <s.neumann@raumfeld.com> Cc: linux-input@vger.kernel.org Cc: Haojian Zhuang <haojian.zhuang@gmail.com>
333 lines
7.9 KiB
C
333 lines
7.9 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.h>
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#include <linux/input/eeti_ts.h>
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#include <linux/slab.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_priv {
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struct i2c_client *client;
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struct input_dev *input;
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struct work_struct work;
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struct mutex mutex;
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int irq_gpio, irq, irq_active_high;
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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 (1 << 0)
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#define REPORT_BIT_AD0 (1 << 1)
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#define REPORT_BIT_AD1 (1 << 2)
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#define REPORT_BIT_HAS_PRESSURE (1 << 6)
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#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
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static inline int eeti_ts_irq_active(struct eeti_ts_priv *priv)
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{
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return gpio_get_value(priv->irq_gpio) == priv->irq_active_high;
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}
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static void eeti_ts_read(struct work_struct *work)
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{
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char buf[6];
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unsigned int x, y, res, pressed, to = 100;
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struct eeti_ts_priv *priv =
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container_of(work, struct eeti_ts_priv, work);
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mutex_lock(&priv->mutex);
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while (eeti_ts_irq_active(priv) && --to)
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i2c_master_recv(priv->client, buf, sizeof(buf));
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if (!to) {
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dev_err(&priv->client->dev,
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"unable to clear IRQ - line stuck?\n");
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goto out;
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}
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/* drop non-report packets */
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if (!(buf[0] & 0x80))
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goto out;
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pressed = buf[0] & REPORT_BIT_PRESSED;
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res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
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x = buf[2] | (buf[1] << 8);
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y = buf[4] | (buf[3] << 8);
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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(priv->input, ABS_PRESSURE, buf[5]);
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input_report_abs(priv->input, ABS_X, x);
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input_report_abs(priv->input, ABS_Y, y);
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input_report_key(priv->input, BTN_TOUCH, !!pressed);
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input_sync(priv->input);
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out:
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mutex_unlock(&priv->mutex);
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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_priv *priv = dev_id;
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/* postpone I2C transactions as we are atomic */
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schedule_work(&priv->work);
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return IRQ_HANDLED;
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}
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static void eeti_ts_start(struct eeti_ts_priv *priv)
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{
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enable_irq(priv->irq);
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/* Read the events once to arm the IRQ */
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eeti_ts_read(&priv->work);
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}
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static void eeti_ts_stop(struct eeti_ts_priv *priv)
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{
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disable_irq(priv->irq);
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cancel_work_sync(&priv->work);
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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_priv *priv = input_get_drvdata(dev);
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eeti_ts_start(priv);
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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_priv *priv = input_get_drvdata(dev);
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eeti_ts_stop(priv);
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}
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static int __devinit 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 eeti_ts_platform_data *pdata = client->dev.platform_data;
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struct eeti_ts_priv *priv;
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struct input_dev *input;
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unsigned int irq_flags;
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int err = -ENOMEM;
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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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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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if (!priv) {
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dev_err(&client->dev, "failed to allocate driver data\n");
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goto err0;
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}
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mutex_init(&priv->mutex);
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input = input_allocate_device();
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if (!input) {
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dev_err(&client->dev, "Failed to allocate input device.\n");
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goto err1;
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}
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input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
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input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(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->dev.parent = &client->dev;
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input->open = eeti_ts_open;
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input->close = eeti_ts_close;
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priv->client = client;
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priv->input = input;
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priv->irq_gpio = pdata->irq_gpio;
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priv->irq = gpio_to_irq(pdata->irq_gpio);
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err = gpio_request_one(pdata->irq_gpio, GPIOF_IN, client->name);
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if (err < 0)
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goto err1;
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if (pdata)
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priv->irq_active_high = pdata->irq_active_high;
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irq_flags = priv->irq_active_high ?
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IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
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INIT_WORK(&priv->work, eeti_ts_read);
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i2c_set_clientdata(client, priv);
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input_set_drvdata(input, priv);
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err = input_register_device(input);
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if (err)
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goto err2;
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err = request_irq(priv->irq, eeti_ts_isr, irq_flags,
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client->name, priv);
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if (err) {
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dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
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goto err3;
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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(priv);
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device_init_wakeup(&client->dev, 0);
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return 0;
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err3:
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input_unregister_device(input);
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input = NULL; /* so we dont try to free it below */
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err2:
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gpio_free(pdata->irq_gpio);
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err1:
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input_free_device(input);
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kfree(priv);
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err0:
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return err;
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}
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static int __devexit eeti_ts_remove(struct i2c_client *client)
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{
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struct eeti_ts_priv *priv = i2c_get_clientdata(client);
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free_irq(priv->irq, priv);
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/*
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* eeti_ts_stop() leaves IRQ disabled. We need to re-enable it
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* so that device still works if we reload the driver.
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*/
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enable_irq(priv->irq);
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input_unregister_device(priv->input);
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kfree(priv);
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return 0;
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}
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#ifdef CONFIG_PM
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static int 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_priv *priv = i2c_get_clientdata(client);
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struct input_dev *input_dev = priv->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(priv);
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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(priv->irq);
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return 0;
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}
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static int 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_priv *priv = i2c_get_clientdata(client);
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struct input_dev *input_dev = priv->input;
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if (device_may_wakeup(&client->dev))
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disable_irq_wake(priv->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(priv);
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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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#endif
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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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#ifdef CONFIG_PM
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.pm = &eeti_ts_pm,
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#endif
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},
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.probe = eeti_ts_probe,
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.remove = __devexit_p(eeti_ts_remove),
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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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