【MediaTek X20开发板试用体验】3.MTX20开发板串口测试方法，adb+wifi，添加新的驱动和应用程序验证。

开发板

嵌入式开发调试方法很重要，我们先来看看MTX20板子的调试方式。
一）串口log，本来以为96boards的板子应该是一样，可实际结果不一样（MTX20使用android系统，另外一块板子使用linux系统，难道是这个原因？），注意USB转TTL线是1.8V。

PC端串口调试助手设置如下，可选择的最大波特率，比较特殊。说明一下此时串口输出的log比较多，还没有完全搞清楚输出机制，不一定每次开机都可以有串口log输出原因未知。

二）adb+wifi调试
adb+u***方式很简单，注意MTX20开发板USB Device和HOST模式切换。
adb+wifi设置步骤：
1.adb+u***输入情况下：
adb shell
getprop service.adb.tcp.port 5555
setprop service.adb.tcp.port 5555
stop adbd
（此时adb连接自动断开）
2.不断电，将u***切换到host模式
设置wifi静态ip地址： 192.168.9.233
3.设置setting-》Developer options-》USB debugging开启
4.adb+wifi连接：
adb connect 192.168.9.233:5555

adb shell可以正常连接开发板。
三）添加新驱动和应用测试
1.驱动源代码和位置

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
struct xble_device_data {
struct block_device *binding;
int inuse;
};
#define mtx20_unflatten_dts_TIP "mtx20_unflatten_dts_tip"
#define DEV_NAME "ds1302_cdev"
char mtx20_unflatten_dts_code[64] = "mtx20_unflatten_dts, mtx20_unflatten_dts_show";
int ds1302_major = 217;
dev_t ds1302_devno;
struct ds1302_cdev_t {
struct cdev cdev;
} ds1302_dev;
static struct class *xble_class;
static struct xble_device_data *xble_devices;
static DEFINE_MUTEX(xble_mutex);
static int max_xble_minors = 2;
module_param(max_xble_minors, int, 0);
MODULE_PARM_DESC(max_xble_minors, "Maximum number of xble devices (1-65536)");
int g_nNum = 99;
int ds1302_open(struct inode *inode, struct file *filep)
{
int nNum = 99;
pr_warn("20170116 open nNum=%d g_nNum=%dn", nNum, g_nNum);
printk( "20170116 open =11= g_nNum=%dn", g_nNum);
return 0;
}
static const struct file_operations ds1302_fops = {
.owner = THIS_MODULE,
.open = ds1302_open,
};
static ssize_t show(struct device_driver *driver, char *buf)
{
if(NULL != buf)
{
/* Newline is not appended on purpose, for convenience of reader programs */
snprintf(buf, PAGE_SIZE, "%sn", mtx20_unflatten_dts_code);
return strlen(buf);
}
return 0;
}
DRIVER_ATTR(mtx20_unflatten_dts, 0444, show, NULL);
static struct attribute *mtx20_unflatten_dts_attrs[] = {
&driver_attr_mtx20_unflatten_dts.attr,
NULL,
};
static struct attribute_group mtx20_unflatten_dts_group = {
.name ="mtx20_unflatten_dts",
.attrs = mtx20_unflatten_dts_attrs,
};
static const struct attribute_group *mtx20_unflatten_dts_groups[] = {
&mtx20_unflatten_dts_group,
NULL,
};
static char *xble_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "xble/%s", dev_name(dev));
}
static int mtx20_unflatten_dts_probe(struct platform_device *pdev)
{
int nNum;
int ret;
const char *m_string;
printk("-0000-mtx20_unflatten_dts_proben");
if(NULL == pdev)
{
printk("xiaomi_test: mtx20_unflatten_dts_probe failed, pdev is NULLn");
return 0;
}
pr_warn("mtx20_unflatten_dts_probe 0004n");
if(NULL == pdev->dev.of_node)
{
printk( "xiaomi_test: mtx20_unflatten_dts_probe failed, of_node is NULLn");
return 0;
}
/* mtx20_unflatten_dts_TIP*/
if(of_property_read_bool(pdev->dev.of_node, mtx20_unflatten_dts_TIP))
{
printk( "mtx20_unflatten_dts_probe: dtsi<%s> is existingn", mtx20_unflatten_dts_TIP);
}
if (of_property_read_u32(pdev->dev.of_node, "linux,code", &nNum))
{
printk(KERN_INFO "=11= nNum=%dn", nNum);
}
else
{
printk(KERN_INFO "=0101= nNum=%dn", nNum);
}
g_nNum = nNum;
if (of_property_read_string(pdev->dev.of_node, "linux,string", &m_string))
{
printk(KERN_INFO "=11= m_string=%sn", m_string);
}
else
{
printk(KERN_INFO "=12= m_string=%sn", m_string);
}
printk(KERN_INFO "=0102= nNum=%dn", nNum);
if (ds1302_major) {
ds1302_devno = MKDEV(ds1302_major, 0);
register_chrdev_region(ds1302_devno, 1, DEV_NAME);
} else {
alloc_chrdev_region(&ds1302_devno, 0, 1, DEV_NAME);
}
printk("-00001-mtx20_unflatten_dts_probe max_xble_minors=%dn", max_xble_minors);
printk(KERN_INFO "=0103= nNum=%dn", nNum);
xble_devices = vzalloc(sizeof(struct xble_device_data) * max_xble_minors);
if (!xble_devices) {
printk(KERN_ERR "Not enough memory for xble device structuresn");
ret = -ENOMEM;
printk("-000011-mtx20_unflatten_dts_probe max_xble_minors=%dn", max_xble_minors);
goto error;
}
printk(KERN_INFO "=0104= nNum=%dn", nNum);
cdev_init(&ds1302_dev.cdev, &ds1302_fops);
ds1302_dev.cdev.owner = THIS_MODULE;
if ((ret = cdev_add(&ds1302_dev.cdev, ds1302_devno, 1) < 0)) {
unregister_chrdev_region(ds1302_devno, 1);
goto error;
}
printk(KERN_INFO "=0105= nNum=%dn", nNum);
xble_class = class_create(THIS_MODULE, "xble");
if (IS_ERR(xble_class)) {
printk(KERN_ERR "Error creating xble class.n");
cdev_del(&ds1302_dev.cdev);
ret = PTR_ERR(xble_class);
goto error_region;
}
printk(KERN_INFO "=0106= nNum=%dn", nNum);
xble_class->devnode = xble_devnode;
device_create(xble_class, NULL, MKDEV(ds1302_major, 0), NULL, "xblectl");
printk(KERN_INFO "=0107= nNum=%dn", nNum);
error_region:
unregister_chrdev_region(ds1302_devno, max_xble_minors);
error:
vfree(xble_devices);
return 0;
}
static struct of_device_id mtx20_unflatten_dts_info_match_table[] = {
{ .compatible = "mediatek,mtx20_unflatten_dts",},
{ },
};
static struct platform_driver mtx20_unflatten_dts = {
.driver = {
.name = "mtx20_unflatten_dts",
.owner = THIS_MODULE,
.groups = mtx20_unflatten_dts_groups,
.of_match_table = mtx20_unflatten_dts_info_match_table,
},
.probe = mtx20_unflatten_dts_probe,
.remove = NULL,
};
static int __init mtx20_unflatten_dts_init(void)
{
pr_warn("mtx20_unflatten_dts_init 0004n");
return platform_driver_register(&mtx20_unflatten_dts);
}
static void __exit mtx20_unflatten_dts_exit(void)
{
device_destroy(xble_class, ds1302_devno);
class_destroy(xble_class);
cdev_del(&ds1302_dev.cdev);
unregister_chrdev_region(ds1302_devno, 1);
platform_driver_unregister(&mtx20_unflatten_dts);
}
module_init(mtx20_unflatten_dts_init);
module_exit(mtx20_unflatten_dts_exit);
MODULE_LICENSE("GPL");

复制代码

位置：android6.0.0/kernel-3.18/drivers/pinctrl/mediatek下，这个位置可以任意只要可以编译即可。
2.dts设置

mtx20_unflatten_dts: mtx20_unflatten_dts@10030000 {
compatible = "mediatek,mtx20_unflatten_dts";
#address-cells = <3>;
#size-cells = <1>;
mtx20_unflatten_dts_tip;
linux,code = <20170111>;
linux,string = "MediaTek X20-0000-";
};

复制代码

android-6.0.0/kernel-3.18/arch/arm64/boot/dts下mt6797.dtsi文件中。
3.linux kernel编译开关设置
android-6.0.0/kernel-3.18/arch/arm64下Kconfig文件中添加
select MTX20_UNFLATTEN_DTS
然后编译更新boot.img。
4.应用程序源代码