Re: [PATCH] input: add maxim max11801 resistance touchscreencontroller driver.

From: Dmitry Torokhov
Date: Wed Apr 06 2011 - 13:08:51 EST


Hi Zhang,

On Wed, Apr 06, 2011 at 11:52:22PM +0800, Jiejing Zhang wrote:
> From: Zhang Jiejing <jiejing.zhang@xxxxxxxxxxxxx>
>
> Add MAXI max11801 resistance touch screen controller driver,
> This driver use Auto Mode and Aperture Mode.
>
> Other max1180x driver can support in this driver, they use
> almost same register address and define, you can find a table in
> max11801_ts.c
>
> You can find data sheet under this link:
> http://www.maxim-ic.com/datasheet/index.mvp/id/5943
>
> Signed-off-by: Zhang Jiejing <jiejing.zhang@xxxxxxxxxxxxx>
> ---
> drivers/input/touchscreen/Kconfig | 12 ++
> drivers/input/touchscreen/Makefile | 1 +
> drivers/input/touchscreen/max11801_ts.c | 293 +++++++++++++++++++++++++++++++
> 3 files changed, 306 insertions(+), 0 deletions(-)
> create mode 100644 drivers/input/touchscreen/max11801_ts.c
>
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index 434fd80..a1067af 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -714,4 +714,16 @@ config TOUCHSCREEN_TPS6507X
> To compile this driver as a module, choose M here: the
> module will be called tps6507x_ts.
>
> +config TOUCHSCREEN_MAX11801
> + tristate "MAX11801 based touchscreens"
> + depends on I2C
> + help
> + Say Y here if you have a MAX11801 based touchscreen
> + controller
> +
> + If unsure, say N.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called max11801_ts
> +
> endif
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index ca94098..d2302f9 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -59,3 +59,4 @@ obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE) += mainstone-wm97xx.o
> obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE) += zylonite-wm97xx.o
> obj-$(CONFIG_TOUCHSCREEN_W90X900) += w90p910_ts.o
> obj-$(CONFIG_TOUCHSCREEN_TPS6507X) += tps6507x-ts.o
> +obj-$(CONFIG_TOUCHSCREEN_MAX11801) += max11801_ts.o
> diff --git a/drivers/input/touchscreen/max11801_ts.c b/drivers/input/touchscreen/max11801_ts.c
> new file mode 100644
> index 0000000..cdbd3c6
> --- /dev/null
> +++ b/drivers/input/touchscreen/max11801_ts.c
> @@ -0,0 +1,293 @@
> +/*
> + * max11801_ts.c - Driver for MAXI MAX11801 - A Resistive touch screen

No filenames in comments please.

> + * controller with i2c interface
> + *
> + * Copyright (C) 2011 Freescale Semiconductor, Inc.
> + * Author: Zhang Jiejing <jiejing.zhang@xxxxxxxxxxxxx>
> + *
> + * Based on mcs5000_ts.c
> + *
> + * This program 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.
> + */
> +
> +/* This driver is aim for support the serial of MAXI touch chips
> + * max11801-max11803, the main different of this 4 chips can get from
> + * this table
> + * -----------------------------------------------------
> + * | CHIP | AUTO MODE SUPPORT(FIFO) | INTERFACE |
> + * |----------------------------------------------------|
> + * | max11800 | YES | SPI |
> + * | max11801 | YES | I2C |
> + * | max11802 | NO | SPI |
> + * | max11803 | NO | I2C |
> + * ------------------------------------------------------
> + *
> + * Currently, this driver only support max11801.
> + *
> + * Data Sheet:
> + * http://www.maxim-ic.com/datasheet/index.mvp/id/5943
> + * */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/input.h>
> +#include <linux/irq.h>
> +#include <linux/slab.h>
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +
> +/* Register Address define */
> +#define GENERNAL_STATUS_REG 0x00
> +#define GENERNAL_CONF_REG 0x01
> +#define MESURE_RES_CONF_REG 0x02
> +#define MESURE_AVER_CONF_REG 0x03
> +#define ADC_SAMPLE_TIME_CONF_REG 0x04
> +#define PANEL_SETUPTIME_CONF_REG 0x05
> +#define DELAY_CONVERSION_CONF_REG 0x06
> +#define TOUCH_DETECT_PULLUP_CONF_REG 0x07
> +#define AUTO_MODE_TIME_CONF_REG 0x08 /* only for max11800/max11801 */
> +#define APERTURE_CONF_REG 0x09 /* only for max11800/max11801 */
> +#define AUX_MESURE_CONF_REG 0x0a
> +#define OP_MODE_CONF_REG 0x0b
> +
> +/* FIFO is only in max11800 & max11801 */
> +#define FIFO_RD_CMD (0x50 << 1)
> +#define MAX11801_FIFO_INT (1 << 2)
> +#define MAX11801_FIFO_OVERFLOW (1 << 3)
> +
> +#define XY_BUFSIZE 4
> +#define XY_BUF_OFFSET 4
> +
> +#define MAX11801_MAX_X 0xfff
> +#define MAX11801_MAX_Y 0xfff
> +
> +#define MEASURE_TAG_OFFSET 2
> +#define MEASURE_TAG_MASK (3 << MEASURE_TAG_OFFSET)
> +#define EVENT_TAG_OFFSET 0
> +#define EVENT_TAG_MASK (3 << EVENT_TAG_OFFSET)
> +#define MEASURE_X_TAG (0 << MEASURE_TAG_OFFSET)
> +#define MEASURE_Y_TAG (1 << MEASURE_TAG_OFFSET)
> +
> +/* These are the state of touch event state machine */
> +enum {
> + EVENT_INIT,
> + EVENT_MIDDLE,
> + EVENT_RELEASE,
> + EVENT_FIFO_END
> +};
> +
> +struct max11801_data {
> + struct i2c_client *client;
> + struct input_dev *input_dev;
> + struct delayed_work work;
> + struct workqueue_struct *workq;
> +};
> +
> +static u8 read_register(struct i2c_client *client, int addr)
> +{
> + /* XXX: The chip ignore LSB of register address */

s/ignore/ignores/


> + return i2c_smbus_read_byte_data(client, addr << 1);
> +}
> +
> +static int max11801_write_reg(struct i2c_client *client, int addr, int data)
> +{
> + /* XXX: The chip ignore LSB of register address */

s/ignore/ignores/

> + return i2c_smbus_write_byte_data(client, addr << 1, data);
> +}
> +
> +static void max11801_ts_work(struct work_struct *work)
> +{
> + struct max11801_data *data = container_of(to_delayed_work(work),
> + struct max11801_data, work);
> + struct i2c_client *client = data->client;
> + int status, i, ret;
> + u8 buf[XY_BUFSIZE];
> + int x = -1;
> + int y = -1;
> +
> + status = read_register(data->client, GENERNAL_STATUS_REG);
> + while (status & (MAX11801_FIFO_INT | MAX11801_FIFO_OVERFLOW)) {
> + status = read_register(data->client, GENERNAL_STATUS_REG);
> +
> + ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_CMD,
> + XY_BUFSIZE, buf);
> +
> + /* We will get 4 bytes buffer that contains X,Y and event tag */
> + if (ret < XY_BUFSIZE)
> + continue;
> +
> + for (i = 0; i < XY_BUFSIZE; i += XY_BUFSIZE / 2) {
> + if ((buf[i+1] & MEASURE_TAG_MASK) == MEASURE_X_TAG)
> + x = (buf[i] << XY_BUF_OFFSET) + (buf[i+1] >> XY_BUF_OFFSET);
> + else if ((buf[i+1] & MEASURE_TAG_MASK) == MEASURE_Y_TAG)
> + y = (buf[i] << XY_BUF_OFFSET) + (buf[i+1] >> XY_BUF_OFFSET);
> + }
> +
> + if ((buf[1] & EVENT_TAG_MASK) != (buf[3] & EVENT_TAG_MASK))
> + continue;
> +
> + switch (buf[1] & EVENT_TAG_MASK) { /* What status of current p */
> + case EVENT_INIT:
> + case EVENT_MIDDLE:
> + input_report_abs(data->input_dev, ABS_X, x);
> + input_report_abs(data->input_dev, ABS_Y, y);
> + input_report_abs(data->input_dev, ABS_PRESSURE, 1);

If the device does not provide true pressure reading you should not
report fake values. Please do not report ABS_PRESSURE and remove it from
device capabilities.

> + input_event(data->input_dev, EV_KEY, BTN_TOUCH, 1);
> + input_sync(data->input_dev);
> + break;
> + case EVENT_RELEASE:
> + input_report_abs(data->input_dev, ABS_PRESSURE, 0);
> + input_event(data->input_dev, EV_KEY, BTN_TOUCH, 0);
> + input_sync(data->input_dev);
> + break;
> + case EVENT_FIFO_END:
> + break;
> + }
> + }
> + enable_irq(client->irq);
> +}
> +
> +static void max11801_ts_phy_init(struct max11801_data *data)
> +{
> + struct i2c_client *client = data->client;
> +
> + /* Average X,Y, take 16 samples, average eight media sample */
> + max11801_write_reg(client, MESURE_AVER_CONF_REG, 0xff);
> + /* X,Y panel setup time set to 20us */
> + max11801_write_reg(client, PANEL_SETUPTIME_CONF_REG, 0x11);
> + /* Rough pullup time (2uS), Fine pullup time (10us) */
> + max11801_write_reg(client, TOUCH_DETECT_PULLUP_CONF_REG, 0x10);
> + /* Auto mode init period = 5ms , scan period = 5ms*/
> + max11801_write_reg(client, AUTO_MODE_TIME_CONF_REG, 0xaa);
> + /* Aperture X,Y set to +- 4LSB */
> + max11801_write_reg(client, APERTURE_CONF_REG, 0x33);
> + /* Enable Power, enable Automode, enable Aperture, enable Average X,Y */
> + max11801_write_reg(client, OP_MODE_CONF_REG, 0x36);
> +}
> +
> +static irqreturn_t max11801_irq(int irq, void *dev)
> +{
> + struct max11801_data *data = dev;
> + disable_irq_nosync(irq);
> + queue_delayed_work(data->workq, &data->work, 0);
> + return IRQ_HANDLED;

You should be using request_threaded_irq() and get rid of your private
workqueue.

> +}
> +
> +static int __devinit max11801_ts_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + struct max11801_data *data;
> + struct input_dev *input_dev;
> + int ret;
> +
> + data = kzalloc(sizeof(struct max11801_data), GFP_KERNEL);
> + if (!data) {
> + dev_err(&client->dev, "Failed to allocate memory\n");
> + return -ENOMEM;
> + }
> +
> + input_dev = input_allocate_device();
> + if (!input_dev) {
> + dev_err(&client->dev, "Failed to allocate memory\n");
> + ret = -ENOMEM;
> + goto err_free_mem;
> + }
> +
> + data->client = client;
> + data->input_dev = input_dev;
> + max11801_ts_phy_init(data);
> + INIT_DELAYED_WORK(&data->work, max11801_ts_work);
> + data->workq = create_singlethread_workqueue("max11801_ts");
> + if (!data->workq) {
> + dev_err(&client->dev, "Failed to create workqueue\n");
> + ret = -ENOMEM;
> + goto err_free_wq;
> + }
> +
> + input_dev->name = "max11801_ts";
> + input_dev->id.bustype = BUS_I2C;
> + input_dev->dev.parent = &client->dev;
> +
> + __set_bit(EV_ABS, input_dev->evbit);
> + __set_bit(EV_KEY, input_dev->evbit);
> + __set_bit(BTN_TOUCH, input_dev->keybit);
> + __set_bit(ABS_X, input_dev->absbit);
> + __set_bit(ABS_Y, input_dev->absbit);
> + __set_bit(ABS_PRESSURE, input_dev->absbit);
> + input_set_abs_params(input_dev, ABS_X, 0, MAX11801_MAX_X, 0, 0);
> + input_set_abs_params(input_dev, ABS_Y, 0, MAX11801_MAX_Y, 0, 0);
> + input_set_drvdata(input_dev, data);
> +
> + ret = request_irq(client->irq, max11801_irq,
> + IRQF_TRIGGER_LOW, "max11801_ts", data);
> + if (ret < 0) {
> + dev_err(&client->dev, "Failed to register interrupt\n");
> + goto err_free_dev;
> + }
> +
> + ret = input_register_device(data->input_dev);
> + if (ret < 0)
> + goto err_free_irq;
> + i2c_set_clientdata(client, data);
> + return 0;
> +
> +err_free_irq:
> + free_irq(client->irq, data);
> +err_free_wq:
> + destroy_workqueue(data->workq);
> +err_free_dev:
> + input_free_device(input_dev);
> +err_free_mem:
> + kfree(data);
> + return ret;
> +}
> +
> +static __devexit int max11801_ts_remove(struct i2c_client *client)
> +{
> + struct max11801_data *data = i2c_get_clientdata(client);
> +
> + free_irq(client->irq, data);
> + cancel_delayed_work_sync(&data->work);
> + destroy_workqueue(data->workq);
> + input_unregister_device(data->input_dev);
> + input_free_device(data->input_dev);
> + kfree(data);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id max11801_ts_id[] = {
> + {"max11801", 0},
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, max11801_ts_id);
> +
> +static struct i2c_driver max11801_ts_driver = {
> + .probe = max11801_ts_probe,
> + .remove = __devexit_p(max11801_ts_remove),
> + .driver = {
> + .name = "max11801_ts",
> + },
> + .id_table = max11801_ts_id,
> +};
> +
> +static int __init max11801_ts_init(void)
> +{
> + return i2c_add_driver(&max11801_ts_driver);
> +}
> +
> +static void __exit max11801_ts_exit(void)
> +{
> + i2c_del_driver(&max11801_ts_driver);
> +}
> +
> +module_init(max11801_ts_init);
> +module_exit(max11801_ts_exit);
> +
> +MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@xxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Touchscreen driver for MAXI MAX11801 controller");
> +MODULE_LICENSE("GPL");

Thanks.

--
Dmitry
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