# evtest /dev/event0
或者
# hexdump /dev/event0
//
分析：
\drivers\i2c\busses\I2c-digicolor.c
static struct platform_driver i2c_dc_driver = {
.probe = i2c_dc_probe,
.remove = __exit_p(i2c_dc_remove),
.driver = {
.name = "i2c-digicolor",
.owner = THIS_MODULE,
},
};
static int i2c_dc_probe(struct platform_device *dev)
--->i2c->adap.algo = &i2c_dc_algorithm;
static const struct i2c_algorithm i2c_dc_algorithm = {
.master_xfer = i2c_dc_xfer,
.functionality = i2c_dc_functionality,
};
static int i2c_dc_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
--->i2c_dc_fatal_error(i2c, "excess retries");
在文件
\drivers\input\dc\Gt9xx.c
static int __devinit goodix_ts_init(void)
---> ret = i2c_add_driver(&goodix_ts_driver);
static struct i2c_driver goodix_ts_driver = {
.probe = goodix_ts_probe,
.remove = goodix_ts_remove,
#ifdef CONFIG_HAS_EARLYSUSPEND
.suspend = goodix_ts_early_suspend,
.resume = goodix_ts_late_resume,
#endif
.id_table = goodix_ts_id,
.driver = {
.name = GTP_I2C_NAME,
.owner = THIS_MODULE,
},
};
static int goodix_ts_probe(struct i2c_client *client, const struct i2c_device_id *id)
--->INIT_WORK(&ts->work, goodix_ts_work_func);
static void goodix_ts_work_func(struct work_struct *work)
--->ret = gtp_i2c_read(ts->client, point_data, 12);
--->ret = i2c_transfer(client->adapter, &msg, 1);
--->ret = adap->algo->master_xfer(adap, msgs, num);
最终调用i2c_dc_xfer
//---------------------------------------------------------------------
//温度传感器Rtc-pcf8563
static int i2c_dc_probe(struct platform_device *dev)
--->i2c_new_probed_device(&i2c->adap, &(i2c_dc_board_list[i].dc_board_info),i2c_dc_board_list[i].dc_board_addr_list);
static struct i2c_dc_board i2c_dc_board_list[] =
--->
//添加i2c子设备
//ljh
#if defined 1
{
{I2C_BOARD_INFO("pcf8563", 0x51)},
{0x51,I2C_CLIENT_END},
},
#endif
\drivers\rtc\Rtc-pcf8563.c
匹配name pcf8563
static struct i2c_driver pcf8563_driver = {
.driver = {
//.name = "rtc-pcf8563",
.name = "pcf8563",
},
.probe = pcf8563_probe,
.remove = pcf8563_remove,
.id_table = pcf8563_id,
};
//-----------------------------------------------------------------------
2015-04-02
问1：内核启动的时候，加载i2c总线驱动，加载pcf8563设备和Goodix-TS设备出错
i2c /dev entries driver
i2c_dc_enable: RA_CSR_GP_MNOP_CTRL = 0x1f1f101f
i2c-digicolor: i2c-1: I2C adapter
i2c-digicolor: registering device dc_maui which has slave addr 0x4a
DigiColor MAUI registered with bus id (1) with slave address 0x4a
Forcing PLL3 to 960 MHz!
Forcing AUD_TX to 24.62 MHz!
dc_maui: read reg_id: ANALOG_TEST_26 addr: 0xbe result: 0x0d (13)
dc_maui: read reg_id: ANALOG_TEST_22 addr: 0xba result: 0x00 (0)
dc_maui: read reg_id: ANALOG_TEST_18 addr: 0xb6 result: 0x00 (0)
i2c-digicolor: registering device pcf8563 which has slave addr 0x51
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: registering device Goodix-TS which has slave addr 0x5d
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
答1：入口跟踪分析
static int i2c_dc_probe(struct platform_device *dev)
---> printk(KERN_INFO "i2c-digicolor: registering device %s which has slave addr 0x%x\n", i2c_dc_board_list[i].dc_board_info.type, i2c_dc_board_list[i].dc_board_addr_list[0]);
i2c_new_probed_device(&i2c->adap, &(i2c_dc_board_list[i].dc_board_info),i2c_dc_board_list[i].dc_board_addr_list);
问2：加载gt9xx 驱动后错误信息：
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
<<-GTP-ERROR->> I2C retry timeout, reset chip.
<<-GTP-INFO->> I2C write end_cmd error!
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
<<-GTP-ERROR->> I2C retry timeout, reset chip.
<<-GTP-ERROR->> I2C transfer error. errno:-121
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
<<-GTP-ERROR->> I2C retry timeout, reset chip.
<<-GTP-INFO->> I2C write end_cmd error!
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
<<-GTP-ERROR->> I2C retry timeout, reset chip.
<<-GTP-ERROR->> I2C transfer error. errno:-121
一直循环打印出来
答2：i2c总线挂载了3个i2c从设备，上拉电阻改小，由4.7k改成1k左右就可以了，电阻小的话驱动能力加强了！
问3： i2c_client和i2c_driver结构体在设备驱动层如何填充？
答3： i2c驱动由3个部分组成，总线驱动层，核心驱动层，设备驱动层，
平时我们移植驱动的话主要是移植设备驱动层， i2c_client和i2c_driver结构体都是设备驱动层相关的结构体
问4：定时36ms刷新触摸电容ic的数据，这些数据如何定义？
point_data[0]=129
point_data[1]=78
point_data[2]=0
point_data[3]=129
point_data[4]=11
point_data[5]=99
point_data[6]=31
point_data[7]=217
point_data[8]=29
point_data[9]=242
point_data[10]=194
point_data[11]=250
point_data[12]=0
point_data[13]=0
finger = 0
point_data[0]=129
point_data[1]=78
point_data[2]=0
point_data[3]=129
point_data[4]=11
point_data[5]=99
point_data[6]=31
point_data[7]=217
point_data[8]=29
point_data[9]=242
point_data[10]=194
point_data[11]=250
point_data[12]=0
point_data[13]=0
finger = 0
答4:
这些都是电容屏gt9xx的坐标数据
问5：读取version出错？自己写入i2c，再去取i2c数据，有时候出错，不稳定？拔掉i2c屏幕，还是同样的现象，
如何判定cpu和i2c芯片通信正常？
81,40, b9, 13, fa, 59, 72, c4
185 s 250 y 114 196
# insmod gt9xx.ko
<<-GTP-FUNC->> Func:goodix_ts_init@Line:1621
<<-GTP-FUNC->> Func:goodix_ts_probe@Line:1182
<<-GTP-INFO->> **************************************
<<-GTP-INFO->> GTP Driver Version:V1.5<2013/08/05>
<<-GTP-INFO->> GTP Driver build@15:22:34,Apr 11 2015
<<-GTP-INFO->> GTP I2C Address:0x14
<<-GTP-INFO->> **************************************
<<-GTP-INFO->>
<<-GTP-FUNC->> Func:gtp_i2c_test@Line:958
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
ret=2
test[0]=80
test[1]=47
test[2]=12
<<-GTP-DEBUG->> [806]len1=228,len2=0,len3=0,send_len:228
<<-GTP-DEBUG->> [823]SENSOR ID:0
ljh debug gt9xx
<<-GTP-FUNC->> Func:gtp_init_panel@Line:868
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-DEBUG->> [887]X_MAX = 1280,Y_MAX = 800,TRIGGER = 0x00
<<-GTP-FUNC->> Func:gtp_request_input_dev@Line:1097
input: Goodix Capacitive TouchScreen as /class/input/input1
<<-GTP-DEBUG->> [1048]INT trigger type:0
<<-GTP-ERROR->> Request IRQ failed!ERRNO:1.
<<-GTP-INFO->> GTP works in polling mode.
<<-GTP-FUNC->> Func:gtp_read_version@Line:911
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
<<-GTP-INFO->> IC VERSION:14
IC VERSION:81,40,b9,01,fa,49,f2,d4
<<-GTP-FUNC->> Func:gtp_irq_enable@Line:222
# <<-GTP-FUNC->> Func:goodix_ts_timer_handler@Line:575
<<-GTP-FUNC->> Func:goodix_ts_work_func@Line:328
goodix_ts_work_func
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
point_data[0]=81
point_data[1]=4e
point_data[2]=fb
point_data[3]=81
point_data[4]=10
point_data[5]=e3
point_data[6]=9e
point_data[7]=fa
point_data[8]=1d
point_data[9]=f2
point_data[10]=8a
point_data[11]=fb
point_data[12]=0
point_data[13]=0
finger = 251
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
test_buf[0]=80
test_buf[1]=9d
test_buf[2]=5a
test_buf[3]=5b
test_buf[4]=57
test_buf[5]=65
test_buf[6]=6a
test_buf[7]=6c
test_buf[8]=6d
test_buf[9]=0
test_buf[10]=0
touch_num = 11
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:goodix_ts_timer_handler@Line:575
<<-GTP-FUNC->> Func:goodix_ts_work_func@Line:328
goodix_ts_work_func
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
point_data[0]=81
point_data[1]=4e
point_data[2]=0
point_data[3]=81
point_data[4]=10
point_data[5]=e3
point_data[6]=9e
point_data[7]=fa
point_data[8]=1d
point_data[9]=f2
point_data[10]=8a
point_data[11]=fb
point_data[12]=0
point_data[13]=0
finger = 0
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
test_buf[0]=80
test_buf[1]=9d
test_buf[2]=59
test_buf[3]=5b
test_buf[4]=57
test_buf[5]=66
test_buf[6]=6a
test_buf[7]=6b
test_buf[8]=6d
test_buf[9]=0
test_buf[10]=0
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:goodix_ts_timer_handler@Line:575
<<-GTP-FUNC->> Func:goodix_ts_work_func@Line:328
goodix_ts_work_func
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
point_data[0]=81
point_data[1]=4e
point_data[2]=0
point_data[3]=81
point_data[4]=10
point_data[5]=e3
point_data[6]=9e
point_data[7]=fa
point_data[8]=1d
point_data[9]=f2
point_data[10]=8a
point_data[11]=fb
point_data[12]=0
point_data[13]=0
finger = 0
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
test_buf[0]=80
test_buf[1]=9d
test_buf[2]=59
test_buf[3]=5b
test_buf[4]=57
test_buf[5]=65
test_buf[6]=6a
test_buf[7]=6b
test_buf[8]=6d
test_buf[9]=0
test_buf[10]=0
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:goodix_ts_timer_handler@Line:575
<<-GTP-FUNC->> Func:goodix_ts_work_func@Line:328
goodix_ts_work_func
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
point_data[0]=81
point_data[1]=4e
point_data[2]=0
point_data[3]=81
point_data[4]=10
point_data[5]=e3
point_data[6]=9e
point_data[7]=fa
point_data[8]=1d
point_data[9]=f2
point_data[10]=8a
point_data[11]=fb
point_data[12]=0
point_data[13]=0
finger = 0
答5：写入寄存器数据，再读出寄存器的数据，如果一样就证明通信正常。最好的办法是读只读寄存器的数据，如果读出的值
符合手册要求，就证明cpu与外设通信正常了。
问6：中断方式下无法进入goodix_ts_work_func函数，但是定时查询方式可以进入中断子函数goodix_ts_work_func？
答6：目前把io配置成查询方式
问7：hexdump /dev/event1 分析
地址 秒 微秒 类 code value
按下打印
0000120 1341 0000 4ff0 0001 0003 0000 0211 0000 x坐标0x211 =529
0000130 1341 0000 4ff0 0001 0003 0001 000d 0000 y坐标0x0d =13
0000140 1341 0000 4ff0 0001 0003 0018 00ff 0000
0000150 1341 0000 4ff0 0001 0001 014a 0001 0000
0000160 1341 0000 4ff0 0001 0000 0000 0000 0000
释放打印
0000170 1345 0000 b3b0 0000 0003 0018 0000 0000
0000180 1345 0000 b3b0 0000 0001 014a 0000 0000
0000190 1345 0000 b3b0 0000 0000 0000 0000 0000
问8：加载完触摸驱动后，接上触摸屏硬件，驱动是如何探测到硬件，并打印相关信息？
答8：如果本身是dev，则把dev注册到bus总线上，然后在bus总线搜寻drv，bus_for_each_drv
问9：分析驱动gt9xx加载过程？
答9：
static int __devinit goodix_ts_init(void)
ret = i2c_add_driver(&goodix_ts_driver);
i2c_register_driver
driver->driver.bus = &i2c_bus_type;
bus_for_each_dev(&i2c_bus_type, NULL, driver, __attach_adapter);
参考
struct bus_type i2c_bus_type = {
.name = "i2c",
.match = i2c_device_match,
.probe = i2c_device_probe,
.remove = i2c_device_remove,
.shutdown = i2c_device_shutdown,
.suspend = i2c_device_suspend,
.resume = i2c_device_resume,
};
直接调用
static int i2c_device_match(struct device *dev, struct device_driver *drv)
i2c_match_id(driver->id_table, client)
//匹配设备id和id_table的ID号，如果相同则调用i2c_device_probe
if (strcmp(client->name, id->name) == 0)
static int i2c_device_probe(struct device *dev)
driver->probe(client, i2c_match_id(driver->id_table, client));
调用goodix_ts_probe
//driver和device匹配成功后执行驱动加载
参考
static struct i2c_driver goodix_ts_driver = {
.probe = goodix_ts_probe,
.remove = goodix_ts_remove,
#ifdef CONFIG_HAS_EARLYSUSPEND
.suspend = goodix_ts_early_suspend,
.resume = goodix_ts_late_resume,
#endif
.id_table = goodix_ts_id,
.driver = {
.name = GTP_I2C_NAME,
.owner = THIS_MODULE,
},
};
问10：目前调试gt9xx驱动的时候，在自己搭建的板子上加载驱动时，复位完gt9271芯片后，工作3秒左右，芯片就不能工作了，
现在改成硬件复位的方式工作正常
答10：到时候在自己新做好的pcb板再调试看看，是不是硬件的io驱动能力不行.
或者
# hexdump /dev/event0
//
分析：
\drivers\i2c\busses\I2c-digicolor.c
static struct platform_driver i2c_dc_driver = {
.probe = i2c_dc_probe,
.remove = __exit_p(i2c_dc_remove),
.driver = {
.name = "i2c-digicolor",
.owner = THIS_MODULE,
},
};
static int i2c_dc_probe(struct platform_device *dev)
--->i2c->adap.algo = &i2c_dc_algorithm;
static const struct i2c_algorithm i2c_dc_algorithm = {
.master_xfer = i2c_dc_xfer,
.functionality = i2c_dc_functionality,
};
static int i2c_dc_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
--->i2c_dc_fatal_error(i2c, "excess retries");
在文件
\drivers\input\dc\Gt9xx.c
static int __devinit goodix_ts_init(void)
---> ret = i2c_add_driver(&goodix_ts_driver);
static struct i2c_driver goodix_ts_driver = {
.probe = goodix_ts_probe,
.remove = goodix_ts_remove,
#ifdef CONFIG_HAS_EARLYSUSPEND
.suspend = goodix_ts_early_suspend,
.resume = goodix_ts_late_resume,
#endif
.id_table = goodix_ts_id,
.driver = {
.name = GTP_I2C_NAME,
.owner = THIS_MODULE,
},
};
static int goodix_ts_probe(struct i2c_client *client, const struct i2c_device_id *id)
--->INIT_WORK(&ts->work, goodix_ts_work_func);
static void goodix_ts_work_func(struct work_struct *work)
--->ret = gtp_i2c_read(ts->client, point_data, 12);
--->ret = i2c_transfer(client->adapter, &msg, 1);
--->ret = adap->algo->master_xfer(adap, msgs, num);
最终调用i2c_dc_xfer
//---------------------------------------------------------------------
//温度传感器Rtc-pcf8563
static int i2c_dc_probe(struct platform_device *dev)
--->i2c_new_probed_device(&i2c->adap, &(i2c_dc_board_list[i].dc_board_info),i2c_dc_board_list[i].dc_board_addr_list);
static struct i2c_dc_board i2c_dc_board_list[] =
--->
//添加i2c子设备
//ljh
#if defined 1
{
{I2C_BOARD_INFO("pcf8563", 0x51)},
{0x51,I2C_CLIENT_END},
},
#endif
\drivers\rtc\Rtc-pcf8563.c
匹配name pcf8563
static struct i2c_driver pcf8563_driver = {
.driver = {
//.name = "rtc-pcf8563",
.name = "pcf8563",
},
.probe = pcf8563_probe,
.remove = pcf8563_remove,
.id_table = pcf8563_id,
};
//-----------------------------------------------------------------------
2015-04-02
问1：内核启动的时候，加载i2c总线驱动，加载pcf8563设备和Goodix-TS设备出错
i2c /dev entries driver
i2c_dc_enable: RA_CSR_GP_MNOP_CTRL = 0x1f1f101f
i2c-digicolor: i2c-1: I2C adapter
i2c-digicolor: registering device dc_maui which has slave addr 0x4a
DigiColor MAUI registered with bus id (1) with slave address 0x4a
Forcing PLL3 to 960 MHz!
Forcing AUD_TX to 24.62 MHz!
dc_maui: read reg_id: ANALOG_TEST_26 addr: 0xbe result: 0x0d (13)
dc_maui: read reg_id: ANALOG_TEST_22 addr: 0xba result: 0x00 (0)
dc_maui: read reg_id: ANALOG_TEST_18 addr: 0xb6 result: 0x00 (0)
i2c-digicolor: registering device pcf8563 which has slave addr 0x51
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: registering device Goodix-TS which has slave addr 0x5d
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
答1：入口跟踪分析
static int i2c_dc_probe(struct platform_device *dev)
---> printk(KERN_INFO "i2c-digicolor: registering device %s which has slave addr 0x%x\n", i2c_dc_board_list[i].dc_board_info.type, i2c_dc_board_list[i].dc_board_addr_list[0]);
i2c_new_probed_device(&i2c->adap, &(i2c_dc_board_list[i].dc_board_info),i2c_dc_board_list[i].dc_board_addr_list);
问2：加载gt9xx 驱动后错误信息：
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
<<-GTP-ERROR->> I2C retry timeout, reset chip.
<<-GTP-INFO->> I2C write end_cmd error!
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
<<-GTP-ERROR->> I2C retry timeout, reset chip.
<<-GTP-ERROR->> I2C transfer error. errno:-121
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
<<-GTP-ERROR->> I2C retry timeout, reset chip.
<<-GTP-INFO->> I2C write end_cmd error!
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
i2c-digicolor: error: excess retries
i2c_dc: msg_num: 0 msg_idx: -11 msg_ptr: 0, bus: 0f cmd: 0a
<<-GTP-ERROR->> I2C retry timeout, reset chip.
<<-GTP-ERROR->> I2C transfer error. errno:-121
一直循环打印出来
答2：i2c总线挂载了3个i2c从设备，上拉电阻改小，由4.7k改成1k左右就可以了，电阻小的话驱动能力加强了！
问3： i2c_client和i2c_driver结构体在设备驱动层如何填充？
答3： i2c驱动由3个部分组成，总线驱动层，核心驱动层，设备驱动层，
平时我们移植驱动的话主要是移植设备驱动层， i2c_client和i2c_driver结构体都是设备驱动层相关的结构体
问4：定时36ms刷新触摸电容ic的数据，这些数据如何定义？
point_data[0]=129
point_data[1]=78
point_data[2]=0
point_data[3]=129
point_data[4]=11
point_data[5]=99
point_data[6]=31
point_data[7]=217
point_data[8]=29
point_data[9]=242
point_data[10]=194
point_data[11]=250
point_data[12]=0
point_data[13]=0
finger = 0
point_data[0]=129
point_data[1]=78
point_data[2]=0
point_data[3]=129
point_data[4]=11
point_data[5]=99
point_data[6]=31
point_data[7]=217
point_data[8]=29
point_data[9]=242
point_data[10]=194
point_data[11]=250
point_data[12]=0
point_data[13]=0
finger = 0
答4:
这些都是电容屏gt9xx的坐标数据
问5：读取version出错？自己写入i2c，再去取i2c数据，有时候出错，不稳定？拔掉i2c屏幕，还是同样的现象，
如何判定cpu和i2c芯片通信正常？
81,40, b9, 13, fa, 59, 72, c4
185 s 250 y 114 196
# insmod gt9xx.ko
<<-GTP-FUNC->> Func:goodix_ts_init@Line:1621
<<-GTP-FUNC->> Func:goodix_ts_probe@Line:1182
<<-GTP-INFO->> **************************************
<<-GTP-INFO->> GTP Driver Version:V1.5<2013/08/05>
<<-GTP-INFO->> GTP Driver build@15:22:34,Apr 11 2015
<<-GTP-INFO->> GTP I2C Address:0x14
<<-GTP-INFO->> **************************************
<<-GTP-INFO->>
<<-GTP-FUNC->> Func:gtp_i2c_test@Line:958
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
ret=2
test[0]=80
test[1]=47
test[2]=12
<<-GTP-DEBUG->> [806]len1=228,len2=0,len3=0,send_len:228
<<-GTP-DEBUG->> [823]SENSOR ID:0
ljh debug gt9xx
<<-GTP-FUNC->> Func:gtp_init_panel@Line:868
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-DEBUG->> [887]X_MAX = 1280,Y_MAX = 800,TRIGGER = 0x00
<<-GTP-FUNC->> Func:gtp_request_input_dev@Line:1097
input: Goodix Capacitive TouchScreen as /class/input/input1
<<-GTP-DEBUG->> [1048]INT trigger type:0
<<-GTP-ERROR->> Request IRQ failed!ERRNO:1.
<<-GTP-INFO->> GTP works in polling mode.
<<-GTP-FUNC->> Func:gtp_read_version@Line:911
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
<<-GTP-INFO->> IC VERSION:14
IC VERSION:81,40,b9,01,fa,49,f2,d4
<<-GTP-FUNC->> Func:gtp_irq_enable@Line:222
# <<-GTP-FUNC->> Func:goodix_ts_timer_handler@Line:575
<<-GTP-FUNC->> Func:goodix_ts_work_func@Line:328
goodix_ts_work_func
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
point_data[0]=81
point_data[1]=4e
point_data[2]=fb
point_data[3]=81
point_data[4]=10
point_data[5]=e3
point_data[6]=9e
point_data[7]=fa
point_data[8]=1d
point_data[9]=f2
point_data[10]=8a
point_data[11]=fb
point_data[12]=0
point_data[13]=0
finger = 251
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
test_buf[0]=80
test_buf[1]=9d
test_buf[2]=5a
test_buf[3]=5b
test_buf[4]=57
test_buf[5]=65
test_buf[6]=6a
test_buf[7]=6c
test_buf[8]=6d
test_buf[9]=0
test_buf[10]=0
touch_num = 11
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:goodix_ts_timer_handler@Line:575
<<-GTP-FUNC->> Func:goodix_ts_work_func@Line:328
goodix_ts_work_func
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
point_data[0]=81
point_data[1]=4e
point_data[2]=0
point_data[3]=81
point_data[4]=10
point_data[5]=e3
point_data[6]=9e
point_data[7]=fa
point_data[8]=1d
point_data[9]=f2
point_data[10]=8a
point_data[11]=fb
point_data[12]=0
point_data[13]=0
finger = 0
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
test_buf[0]=80
test_buf[1]=9d
test_buf[2]=59
test_buf[3]=5b
test_buf[4]=57
test_buf[5]=66
test_buf[6]=6a
test_buf[7]=6b
test_buf[8]=6d
test_buf[9]=0
test_buf[10]=0
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:goodix_ts_timer_handler@Line:575
<<-GTP-FUNC->> Func:goodix_ts_work_func@Line:328
goodix_ts_work_func
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
point_data[0]=81
point_data[1]=4e
point_data[2]=0
point_data[3]=81
point_data[4]=10
point_data[5]=e3
point_data[6]=9e
point_data[7]=fa
point_data[8]=1d
point_data[9]=f2
point_data[10]=8a
point_data[11]=fb
point_data[12]=0
point_data[13]=0
finger = 0
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
test_buf[0]=80
test_buf[1]=9d
test_buf[2]=59
test_buf[3]=5b
test_buf[4]=57
test_buf[5]=65
test_buf[6]=6a
test_buf[7]=6b
test_buf[8]=6d
test_buf[9]=0
test_buf[10]=0
<<-GTP-FUNC->> Func:gtp_i2c_write@Line:132
<<-GTP-FUNC->> Func:goodix_ts_timer_handler@Line:575
<<-GTP-FUNC->> Func:goodix_ts_work_func@Line:328
goodix_ts_work_func
<<-GTP-FUNC->> Func:gtp_i2c_read@Line:87
point_data[0]=81
point_data[1]=4e
point_data[2]=0
point_data[3]=81
point_data[4]=10
point_data[5]=e3
point_data[6]=9e
point_data[7]=fa
point_data[8]=1d
point_data[9]=f2
point_data[10]=8a
point_data[11]=fb
point_data[12]=0
point_data[13]=0
finger = 0
答5：写入寄存器数据，再读出寄存器的数据，如果一样就证明通信正常。最好的办法是读只读寄存器的数据，如果读出的值
符合手册要求，就证明cpu与外设通信正常了。
问6：中断方式下无法进入goodix_ts_work_func函数，但是定时查询方式可以进入中断子函数goodix_ts_work_func？
答6：目前把io配置成查询方式
问7：hexdump /dev/event1 分析
地址 秒 微秒 类 code value
按下打印
0000120 1341 0000 4ff0 0001 0003 0000 0211 0000 x坐标0x211 =529
0000130 1341 0000 4ff0 0001 0003 0001 000d 0000 y坐标0x0d =13
0000140 1341 0000 4ff0 0001 0003 0018 00ff 0000
0000150 1341 0000 4ff0 0001 0001 014a 0001 0000
0000160 1341 0000 4ff0 0001 0000 0000 0000 0000
释放打印
0000170 1345 0000 b3b0 0000 0003 0018 0000 0000
0000180 1345 0000 b3b0 0000 0001 014a 0000 0000
0000190 1345 0000 b3b0 0000 0000 0000 0000 0000
问8：加载完触摸驱动后，接上触摸屏硬件，驱动是如何探测到硬件，并打印相关信息？
答8：如果本身是dev，则把dev注册到bus总线上，然后在bus总线搜寻drv，bus_for_each_drv
问9：分析驱动gt9xx加载过程？
答9：
static int __devinit goodix_ts_init(void)
ret = i2c_add_driver(&goodix_ts_driver);
i2c_register_driver
driver->driver.bus = &i2c_bus_type;
bus_for_each_dev(&i2c_bus_type, NULL, driver, __attach_adapter);
参考
struct bus_type i2c_bus_type = {
.name = "i2c",
.match = i2c_device_match,
.probe = i2c_device_probe,
.remove = i2c_device_remove,
.shutdown = i2c_device_shutdown,
.suspend = i2c_device_suspend,
.resume = i2c_device_resume,
};
直接调用
static int i2c_device_match(struct device *dev, struct device_driver *drv)
i2c_match_id(driver->id_table, client)
//匹配设备id和id_table的ID号，如果相同则调用i2c_device_probe
if (strcmp(client->name, id->name) == 0)
static int i2c_device_probe(struct device *dev)
driver->probe(client, i2c_match_id(driver->id_table, client));
调用goodix_ts_probe
//driver和device匹配成功后执行驱动加载
参考
static struct i2c_driver goodix_ts_driver = {
.probe = goodix_ts_probe,
.remove = goodix_ts_remove,
#ifdef CONFIG_HAS_EARLYSUSPEND
.suspend = goodix_ts_early_suspend,
.resume = goodix_ts_late_resume,
#endif
.id_table = goodix_ts_id,
.driver = {
.name = GTP_I2C_NAME,
.owner = THIS_MODULE,
},
};
问10：目前调试gt9xx驱动的时候，在自己搭建的板子上加载驱动时，复位完gt9271芯片后，工作3秒左右，芯片就不能工作了，
现在改成硬件复位的方式工作正常
答10：到时候在自己新做好的pcb板再调试看看，是不是硬件的io驱动能力不行.
