10.1.2. CTP调试配置¶
10.1.2.1. 概述¶
相比RTP电阻触摸屏， CTP电容触摸屏的调试稍微繁琐一点，CTP驱动一般由触摸屏原厂提供，经过移植添加到SDK中编译和使用 本章节以GT9xx为例来说明一款新的CTP的调试和移植过程。
10.1.2.2. 内核配置¶
10.1.2.2.1. 驱动移植¶
驱动存放路径：source/linux-5.10/drivers/input/touchscreen/gt9xx
其中source/linux-5.10/drivers/input/touchscreen/Makefile修改添加如下：
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 75924acd8..4be057598 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -116,3 +116,6 @@ obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023) += rohm_bu21023.o
obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_FW) += raspberrypi-ts.o
obj-$(CONFIG_TOUCHSCREEN_IQS5XX) += iqs5xx.o
obj-$(CONFIG_TOUCHSCREEN_ZINITIX) += zinitix.o
+obj-$(CONFIG_INPUT_TOUCHSCREEN) += gt9xx/
其中source/linux-5.10/drivers/input/touchscreen/Kconfig修改添加如下：
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index a8d18a679..6acdc3b63 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1344,5 +1344,7 @@ config TOUCHSCREEN_ZINITIX
To compile this driver as a module, choose M here: the
module will be called zinitix.
-
+source "drivers/input/touchscreen/gt9xx/Kconfig"
注意
请从触摸屏供应商处获取和内核版本匹配的驱动程序，如果版本不匹配则可能编译出错，需要自行适配。
10.1.2.2.2. 内核配置¶
在luban根目录下执行 make km (make kernel-menuconfig)，进入kernel的功能配置，按如下选择：
Linux
Device Drivers
Input device support
[*] Touchscreens
<M> gt9xx based touchscreens
驱动以ko的方式编译后，系统启动后在启动脚本S10mdev自动加载，如下：
start() {
echo -n "Starting $DAEMON... "
start-stop-daemon -S -b -m -p $PIDFILE -x /sbin/mdev -- -df
[ $? -eq 0 ] && echo "OK" || echo "ERROR"
# coldplug modules
find /sys/ -name modalias -print0 | \
xargs -0 sort -u | \
tr '\n' '\0' | \
xargs -0 modprobe -abq
}
小技巧
如果不需要自动加载，可注释掉所示代码，仿照其他启动服务自定义加载服务。
10.1.2.3. DTS参数配置¶
board.dts中要添加的参数选项需要查看驱动代码中所要解析的dts参数而添加，示例如下：
GT9xx驱动程序中所要解析的dts参数
static int gtp_parse_dt(struct device *dev,
struct goodix_ts_platform_data *pdata)
{
int ret;
u32 key_nums;
struct property *prop;
u32 key_map[MAX_KEY_NUMS];
struct device_node *np = dev->of_node;
gtp_parse_dt_coords(dev, pdata);
ret = of_property_read_u32(np, "irq-flags",
&pdata->irq_flags);
if (ret) {
dev_info(dev,
"Failed get int-trigger-type from dts,set default\n");
pdata->irq_flags = GTP_DEFAULT_INT_TRIGGER;
}
of_property_read_u32(np, "goodix,int-sync", &pdata->int_sync);
if (pdata->int_sync)
dev_info(dev, "int-sync enabled\n");
of_property_read_u32(np, "goodix,driver-send-cfg",
&pdata->driver_send_cfg);
if (pdata->driver_send_cfg)
dev_info(dev, "driver-send-cfg enabled\n");
of_property_read_u32(np, "goodix,swap-x2y", &pdata->swap_x2y);
if (pdata->swap_x2y)
dev_info(dev, "swap-x2y enabled\n");
of_property_read_u32(np, "goodix,slide-wakeup", &pdata->slide_wakeup);
if (pdata->slide_wakeup)
dev_info(dev, "slide-wakeup enabled\n");
of_property_read_u32(np, "goodix,auto-update", &pdata->auto_update);
if (pdata->auto_update)
dev_info(dev, "auto-update enabled\n");
of_property_read_u32(np, "goodix,auto-update-cfg",
&pdata->auto_update_cfg);
if (pdata->auto_update_cfg)
dev_info(dev, "auto-update-cfg enabled\n");
of_property_read_u32(np, "goodix,esd-protect", &pdata->esd_protect);
if (pdata->esd_protect)
dev_info(dev, "esd-protect enabled\n");
of_property_read_u32(np, "goodix,type-a-report",
&pdata->type_a_report);
if (pdata->type_a_report)
dev_info(dev, "type-a-report enabled\n");
of_property_read_u32(np, "goodix,resume-in-workqueue",
&pdata->resume_in_workqueue);
if (pdata->resume_in_workqueue)
dev_info(dev, "resume-in-workqueue enabled\n");
of_property_read_u32(np, "goodix,power-off-sleep",
&pdata->power_off_sleep);
if (pdata->power_off_sleep)
dev_info(dev, "power-off-sleep enabled\n");
of_property_read_u32(np, "goodix,pen-suppress-finger",
&pdata->pen_suppress_finger);
if (pdata->pen_suppress_finger)
dev_info(dev, "pen-suppress-finger enabled\n");
prop = of_find_property(np, "touchscreen-key-map", NULL);
if (prop) {
key_nums = prop->length / sizeof(key_map[0]);
key_nums = key_nums > MAX_KEY_NUMS ? MAX_KEY_NUMS : key_nums;
dev_dbg(dev, "key nums %d\n", key_nums);
ret = of_property_read_u32_array(np,
"touchscreen-key-map", key_map,
key_nums);
if (ret) {
dev_err(dev, "Unable to read key codes\n");
pdata->key_nums = 0;
memset(pdata->key_map, 0,
MAX_KEY_NUMS * sizeof(pdata->key_map[0]));
}
pdata->key_nums = key_nums;
memcpy(pdata->key_map, key_map,
key_nums * sizeof(pdata->key_map[0]));
dev_info(dev, "key-map is [%x %x %x %x]\n",
pdata->key_map[0], pdata->key_map[1],
pdata->key_map[2], pdata->key_map[3]);
}
pdata->irq_gpio = of_get_named_gpio(np, "irq-gpios", 0);
if (!gpio_is_valid(pdata->irq_gpio))
dev_err(dev, "No valid irq gpio");
pdata->rst_gpio = of_get_named_gpio(np, "reset-gpios", 0);
if (!gpio_is_valid(pdata->rst_gpio))
dev_err(dev, "No valid rst gpio");
return 0;
}
board.dts中所添加的参数项
&i2c3 {
pinctrl-names = "default";
pinctrl-0 = <&i2c3_pins_a>;
status = "okay";
gt9xx@5d {
status = "okay";
compatible = "goodix,gt9xx";
reg = <0x5d>; //CTP设备地址，可以从规格书中获取
reset-gpios = <&gpio_a 8 GPIO_ACTIVE_LOW>;
irq-gpios = <&gpio_a 9 GPIO_ACTIVE_HIGH>;
irq-flags = <2>;
touchscreen-max-id = <11>;
touchscreen-size-x = <1024>; //CTP x轴的范围
touchscreen-size-y = <600>; //CTP y轴的范围
touchscreen-max-w = <1024>; //MAX width
touchscreen-max-p = <512>; //MAX pressure
goodix,int-sync = <1>;
};
};
CTP设备地址获取：
从规格书中可以看出GT9xx根据初始化时序的不同支持两种设备地址，默认时序的读写地址为0xBA/0xBB,读写地址去掉最后一位读写位就是设备地址，即：0x5d
硬件接线示例图如下：
注意
请务必确保dts所配置的参数和引脚与硬件原理图一致
10.1.2.4. 调试¶
测量硬件通路
测量硬件通路是否正常，测量电压信号是否正常
查看打印信息
在board.dts中修改bootargs，增加“loglevel=8” 调高打印级别，系统启动时或insmod驱动模块时看是否有异常打印
获取坐标信息
如果系统有编译getevent工具，触摸屏有触摸时进行坐标的打印
# getevent获取设备信息
# cat /proc/bus/input/devices 例如：（以GT9xx为例） I: Bus=0018 Vendor=dead Product=beef Version=28bb N: Name="goodix-ts" P: Phys=input/ts S: Sysfs=/devices/virtual/input/input0 U: Uniq= H: Handlers=event0 B: PROP=2 B: EV=b B: KEY=1c00 0 0 0 0 0 B: ABS=6e1800000000000