Transplantation of touchpanel on msm7x27

Debugging touchpanel has been around for a while. Today, the platform is msm7x27, android2.2, and TP is mainly I2C. I2C is not introduced here, but self-search is unclear, this article mainly introduces the content of TP porting on this platform. Note that the platform uses hardware I2C instead of gpio simulation.

1. File nodes of devices and drivers

The device in the/sys/bus/I2C/devices directory is the I2C device described in the i2c_board_info structure,

The device names under/sys/bus/I2C/devices are named according to the i2caddress defined in the i2c_board_info struct.

# Ls

I2c-0

0-0038 // i2c_board_info ("ft5xxx", 0x70> 1),/* This is the slave address of the I2C device */

0-005c // i2c_board_info ("ssd2531", 0x53),/* The slave address of the I2C device */

0-000a // i2c_board_info ("bma200", 0x0a),/* This is the slave address of the I2C device */

0-001e // i2c_board_info ("hmc5883", 0x3c> 1),/* The slave address of the I2C device */

0-003c // i2c_board_info ("ov2655", 0x60> 1)

0-0030

0-0010 // i2c_board_info ("rda5802", 0x20> 1 ),

0-001c // i2c_board_info ("ltr600", 0x38> 1),/* The slave address of the I2C device */

I2c-1

<6> [1.107875] input: ft5xxxas/devices/i2c-0/0-0038/input/input3

# Cd sys/devices/i2c-0

# Ls

Uevent

Name

New_device

Delete_device

Subsystem

Power

0-0038

0-005c

0-000a

0-001e

0-003c

0-0030

0-0010

0-001c

I2c-dev

# Cd 0-005c

# Ls

Uevent

Name

Modalias

Subsystem

Power

#

# CD 0-0038

# Ls

Uevent

Name

Modalias

Subsystem

Power

Driver

Input

# Cat name

Ft5xxx

#

Ii. debugging methods

ADB shell dmesg> dmesg. log;

Alternatively, you can view CAT/proc/kmsg in real time. For example, if the returned coordinates are correct during touch;

After you view the input device in real time, you can go to shell: getevent to list all the event devices. The corresponding operations will output information. Paste the log as follows:

<3> [1, 1.095116] [ft5xxx] entermutitouch _

<3> [1, 1.095168] [ft5xxx] entermutitouch_probe

<3> [2, 1.095183] [ft5xxx] mutitouch_chip-> pdata-> gpio_rst = 41

<3> [1, 1.107221] [ft5xxx] entermutitouch_read_dev

<3> [1, 1.107238] [ft5xxx] entermutitouch _

<3> [1, 1.107356] [ft5xxx] entermutitouch_read

<6> [1, 1.107440] Read ft5302 id = 0x79

<3> [1, 1.107451] [ft5xxx] entermutitouch_write

<3> [1, 1.107558] [ft5xxx] entermutitouch _

<6> [1, 1.107638] Select ctpft5302

<6> [1.108021] input: ft5xxx as/devices/i2c-0/0-0038/input/input3

<3> [1, 1.108341] [ft5xxx] leavemutitouch_probe

3. Modified files:

1. kernel/ARCH/ARM/Mach-Sm/board-msm7x27-qrd.c

Initialize msm7x2x_init upon startup, configure the gpio corresponding to int and rstpin, and the address of I2C device, etc.

# Ifdef config_touchscreen_ft5xxx

I2c_register_board_info (0, ft5xxx_i2c_board_info, array_size (ft5xxx_i2c_board_info ));

Ts_ft5xxx_config_gpio ();

# Endif

The key I2C address is in ft5xxx_i2c_board_info

Static struct i2c_board_infoft5xxx_i2c_board_info [] = {

{

I2c_board_info ("ft5xxx", 0x70> 1 ),

. IRQ = msm_gpio_to_int (ts_ft5xxx_gpio_int ),

. Platform_data = & ft5xxx_ts_data,

},

};

This address is in the 7-bit format and does not include the read/write bits. Generally, the address obtained from datasheet needs to be shifted to the right by one bit. During read/write, the system will perform the processing on its own, I read from the file system that the driver name is shifted, that is, the value passed in from here, but the address of the waveform graph device is still not moved. If the host and Server Load balancer cannot communicate with each other, you can try the one-bit left operation.

2. kernel/Drivers/input/touchscreen/ft5xxx. c

This is the driver file. The two main functions are mutitouch_probe and mutitouch_ts_work,

Mutitouch_probe reads the device ID, sets the device property parameters (acceptable event type, XY coordinate range, device name (must be consistent with drivername), and bus type ), register the input device to create the device node/dev/input/eventx, create the corresponding work and register the sleep function

Mutitouch_ts_work is the associated function after the call of the corresponding work triggered by the interruption. It mainly reads the coordinate information and reports it to the upper layer. To complete this function, you must be familiar with the IC, including read and write commands, the format of the data packet.

3. kernel/ARCH/ARM/configs/msm7627-perf-qrd_defconfig

Configure the macro config_touchscreen_ft5xxx = y.

4. kernel/Drivers/input/touchscreen/makefile

Compile related driver files based on macros

OBJ-$ (config_touchscreen_ft5xxx) + = ft5xxx. o

5. kernel/Drivers/input/touchscreen/kconfig

Config touchscreen_ft5xxx

Tristate "ft5xxx capacitive touchpanel"

Depends on I2C

Iv. Supplement

1. Where is the sda scl set?

Board-msm7x27-qrd.c: msm_i2c_gpio_config ()

Gpio_scl = 60;

Gpio_sda = 61;

2. the reset duration is the low-level duration.

Gpio_set_value (tc_chip-> pdata-> gpio_rst, io_low );

Mdelay (200 );

Gpio_set_value (tc_chip-> pdata-> gpio_rst, io_hight );

Mdelay (2 );

3. Other Related Documents

I2c-msm.c

4. For a TP, in addition to being familiar with datasheet, you need to know the system interfaces provided by Linux.

For example, how to apply for an interruption and how to create a work queue.

5. Reference

Linux subsystem analysis and touch screen driver analysis: the simplest example of adding an input device

Http://blog.csdn.net/Ralph_sqd/article/details/5933388

The hierarchical design concept of Linux Device Driver: inputdev

Http://www.linuxidc.com/Linux/2010-06/26812p2.htm

I2C-based embedded multi-point touch screen Driver Design: A description of the driver Process

Http://www.dzsc.com/data/html/2011-3-11/89104.html

LINUX multi-touch interface: detailed descriptions of input device parameters

Http://tanatseng.blog.163.com/blog/static/174991629201132561941518/

Android multi-point touch: instructions from driver to framework to Application

Http://wenku.baidu.com/view/a6a0ee0b79563c1ec5da7119.html