Re: [PATCH] input: add driver for EETI touchpanels [v4]
From: Jean Delvare <hidden>
Date: 2009-05-16 15:57:23
Hallo Daniel, On Sat, 16 May 2009 11:27:22 +0200, Daniel Mack wrote:
quoted hunk ↗ jump to hunk
This patch adds a driver for EETI's I2C connected touchscreens. Signed-off-by: Daniel Mack <redacted> Tested-by: Sven Neumann <redacted> Cc: Jean Delvare <redacted> --- New version with Dmitry's comments considered: - use work_struct instead of delayed_work - use proper exit path in eeti_ts_read() - always report pressure if we have it - devinit/devexit cleanups drivers/input/touchscreen/Kconfig | 9 + drivers/input/touchscreen/Makefile | 1 + drivers/input/touchscreen/eeti_ts.c | 290 +++++++++++++++++++++++++++++++++++ 3 files changed, 300 insertions(+), 0 deletions(-) create mode 100644 drivers/input/touchscreen/eeti_ts.c (...)--- /dev/null +++ b/drivers/input/touchscreen/eeti_ts.c@@ -0,0 +1,290 @@ +/* + * Touch Screen driver for EETI's I2C connected touch screen panels + * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de> + * + * 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 <ujjwal@kenati.com> + * + * 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 <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/kernel.h> +#include <linux/input.h> +#include <linux/interrupt.h> +#include <linux/i2c.h> +#include <linux/timer.h> +#include <linux/gpio.h> + +static int flip_x; +module_param(flip_x, bool, 0644); +MODULE_PARM_DESC(flip_x, "flip x coordinate"); + +static int flip_y; +module_param(flip_y, bool, 0644); +MODULE_PARM_DESC(flip_y, "flip y coordinate"); + +struct eeti_ts_priv { + struct i2c_client *client; + struct input_dev *input; + struct work_struct work; + struct mutex mutex; + int irq; +}; + +#define EETI_TS_BITDEPTH (11) +#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1) + +#define REPORT_BIT_PRESSED (1 << 0) +#define REPORT_BIT_AD0 (1 << 1) +#define REPORT_BIT_AD1 (1 << 2) +#define REPORT_BIT_HAS_PRESSURE (1 << 6) +#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH) + +static void eeti_ts_read(struct work_struct *work) +{ + char buf[6]; + unsigned int x, y, res, pressed, to = 100; + struct eeti_ts_priv *priv = + container_of(work, struct eeti_ts_priv, work); + + mutex_lock(&priv->mutex); + + while (!gpio_get_value(irq_to_gpio(priv->irq)) && --to) + i2c_master_recv(priv->client, buf, sizeof(buf)); + + if (!to) { + dev_err(&priv->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 = buf[2] | (buf[1] << 8); + y = buf[4] | (buf[3] << 8); + + /* 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(priv->input, ABS_PRESSURE, buf[5]); + + input_report_abs(priv->input, ABS_X, x); + input_report_abs(priv->input, ABS_Y, y); + input_report_key(priv->input, BTN_TOUCH, !!pressed); + input_sync(priv->input); + +out: + mutex_unlock(&priv->mutex); +} + +static irqreturn_t eeti_ts_isr(int irq, void *dev_id) +{ + struct eeti_ts_priv *priv = dev_id; + + /* postpone I2C transactions as we are atomic */ + schedule_work(&priv->work); + + return IRQ_HANDLED; +} + +static int eeti_ts_open(struct input_dev *dev) +{ + struct eeti_ts_priv *priv = input_get_drvdata(dev); + + enable_irq(priv->irq); + + /* Read the events once to arm the IRQ */ + eeti_ts_read(&priv->work); + + return 0; +} + +static void eeti_ts_close(struct input_dev *dev) +{ + struct eeti_ts_priv *priv = input_get_drvdata(dev); + + disable_irq(priv->irq); + cancel_work_sync(&priv->work); +} + +static int __devinit eeti_ts_probe(struct i2c_client *client, + const struct i2c_device_id *idp) +{ + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); + struct eeti_ts_priv *priv; + struct input_dev *input; + int err = -ENOMEM; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
This functionality does not correspond to the I2C access method your code uses. You must check for I2C_FUNC_I2C instead (if you want to check at all - it's essentially optional with the new binding model.)
+ return -EIO;
And this isn't an I/O 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. */
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ dev_err(&client->dev, "failed to allocate driver data\n");
+ goto err0;
+ }
+
+ mutex_init(&priv->mutex);
+ input = input_allocate_device();
+
+ if (!input) {
+ dev_err(&client->dev, "Failed to allocate input device.\n");
+ goto err1;
+ }
+
+ input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+ input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(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->dev.parent = &client->dev;
+ input->open = eeti_ts_open;
+ input->close = eeti_ts_close;
+
+ priv->client = client;
+ priv->input = input;
+ priv->irq = client->irq;
+
+ INIT_WORK(&priv->work, eeti_ts_read);
+ dev_set_drvdata(&client->dev, priv);We have i2c_set_clientdata().
+ input_set_drvdata(input, priv);
+
+ err = input_register_device(input);
+ if (err)
+ goto err1;
+
+ err = request_irq(priv->irq, eeti_ts_isr, IRQF_TRIGGER_FALLING,
+ client->name, priv);
+ if (err) {
+ dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
+ goto err2;
+ }
+
+ /* Disable the irq for now. It will be enabled once the input device
+ * is opened. */
+ disable_irq(priv->irq);
+
+ device_init_wakeup(&client->dev, 0);
+ return 0;
+
+err2:
+ input_unregister_device(input);
+ input = NULL; /* so we dont try to free it below */
+err1:
+ input_free_device(input);
+ kfree(priv);
+err0:
+ dev_set_drvdata(&client->dev, NULL);Should be 2 lines above, before kfree(priv).
+ return err;
+}
+
+static int __devexit eeti_ts_remove(struct i2c_client *client)
+{
+ struct eeti_ts_priv *priv = dev_get_drvdata(&client->dev);We have i2c_get_clientdata().
+ + free_irq(priv->irq, priv); + input_unregister_device(priv->input); + dev_set_drvdata(&client->dev, NULL); + kfree(priv); + + return 0; +}
The rest of the I2C code looks OK. -- Jean Delvare