小白自制Linux开发板七. USB驱动配置

阅读原文时间：2021年10月24日阅读：52

本文章基于
https://whycan.com/t_3087.html
https://whycan.com/t_6021.html
整理

F1c100s芯片支持USB的OTG模式，也就是可以通过更改UsbId拉低或拉高方式定义当前的开发板可以作为host还是device。

usbid 拉高时，开发板作为外设方式。
usbid 拉低时，开发板作为主机方式。

当然除了使用硬件方式，还可以通过Linux系统直接更改当前USB的模式。

在F1c100s中PE2引脚是作为usbid功能来使用，因为为了使用Sunxi-tool 所以我在画原理图的时候默认将PE2做了上拉处理。

这个芯片只有一个usb引脚

为了可以引出更多的usb外设，所以这里使用了FE8.1这个USB Hub芯片，这个芯片最多可以引出4个Usb接口。具体原理图如下：

硬件处理完成，接下来就是软件部分修改了，打开Linux5.7.1内核源码

2.1 首先修改设备树文件arch/arm/boot/dts/suniv-f1c100s.dtsi文件

在soc节点下增加

usb_otg: usb@1c13000 {
compatible = "allwinner,suniv-musb";
reg = <0x01c13000 0x0400>;
clocks = <&ccu CLK_BUS_OTG>;
resets = <&ccu RST_BUS_OTG>;
interrupts = <26>;
interrupt-names = "mc";
phys = <&usbphy 0>;
phy-names = "usb";
extcon = <&usbphy 0>;
allwinner,sram = <&otg_sram 1>;
status = "disabled";
};

usbphy: phy@1c13400 {
compatible = "allwinner,suniv-usb-phy";
reg = <0x01c13400 0x10>;
reg-names = "phy_ctrl";
clocks = <&ccu CLK_USB_PHY0>;
clock-names = "usb0_phy";
resets = <&ccu RST_USB_PHY0>;
reset-names = "usb0_reset";
#phy-cells = <1>;
status = "disabled";
};

2.2 修改arch/arm/boot/dts/suniv-f1c100s-licheepi-nano.dts文件

在文件里面添加

&otg_sram {
status = "okay";
};

&usb_otg {
dr_mode = "host"; /* 三个可选项: otg / host / peripheral 我在这里指定为host模式*/
status = "okay";
};

&usbphy {
usb0_id_det-gpio = <&pio 4 2 GPIO_ACTIVE_HIGH>; /* PE2 */
status = "okay";
};

2.3 修改drivers/phy/allwinner/phy-sun4i-usb.c文件

因为我们在设备树中定义的驱动是suniv-usb-phy，所以我们需要添加这部分代码。

enum sun4i_usb_phy_type {
suniv_phy, //新增枚举值
sun4i_a10_phy,
sun6i_a31_phy,
sun8i_a33_phy,
sun8i_a83t_phy,
sun8i_h3_phy,
sun8i_r40_phy,
sun8i_v3s_phy,
sun50i_a64_phy,
sun50i_h6_phy,
};

//新增以下结构
static const struct sun4i_usb_phy_cfg suniv_cfg = {
.num_phys = 1,
.type = suniv_phy,
.disc_thresh = 3,
.phyctl_offset = REG_PHYCTL_A10,
.dedicated_clocks = true,
};

static const struct of_device_id sun4i_usb_phy_of_match[] = {
{ .compatible = "allwinner,suniv-usb-phy", .data = &suniv_cfg }, //新增配置项
{ .compatible = "allwinner,sun4i-a10-usb-phy", .data = &sun4i_a10_cfg },
{ .compatible = "allwinner,sun5i-a13-usb-phy", .data = &sun5i_a13_cfg },
{ .compatible = "allwinner,sun6i-a31-usb-phy", .data = &sun6i_a31_cfg },
{ .compatible = "allwinner,sun7i-a20-usb-phy", .data = &sun7i_a20_cfg },
{ .compatible = "allwinner,sun8i-a23-usb-phy", .data = &sun8i_a23_cfg },
{ .compatible = "allwinner,sun8i-a33-usb-phy", .data = &sun8i_a33_cfg },
{ .compatible = "allwinner,sun8i-a83t-usb-phy", .data = &sun8i_a83t_cfg },
{ .compatible = "allwinner,sun8i-h3-usb-phy", .data = &sun8i_h3_cfg },
{ .compatible = "allwinner,sun8i-r40-usb-phy", .data = &sun8i_r40_cfg },
{ .compatible = "allwinner,sun8i-v3s-usb-phy", .data = &sun8i_v3s_cfg },
{ .compatible = "allwinner,sun50i-a64-usb-phy",
.data = &sun50i_a64_cfg},
{ .compatible = "allwinner,sun50i-h6-usb-phy", .data = &sun50i_h6_cfg },
{ },
};

2.4 修改drivers/usb/musb/sunxi.c文件

这里主要处理设备树中定义的驱动suniv-musb。

static int sunxi_musb_probe(struct platform_device *pdev)
{
struct musb_hdrc_platform_data pdata;
struct platform_device_info pinfo;
struct sunxi_glue *glue;
struct device_node *np = pdev->dev.of_node;
int ret;

if (!np) {  
    dev\_err(&pdev->dev, "Error no device tree node found\\n");  
    return -EINVAL;  
}

glue = devm\_kzalloc(&pdev->dev, sizeof(\*glue), GFP\_KERNEL);  
if (!glue)  
    return -ENOMEM;

memset(&pdata, 0, sizeof(pdata));  
switch (usb\_get\_dr\_mode(&pdev->dev)) {

#if defined CONFIG_USB_MUSB_DUAL_ROLE || defined CONFIG_USB_MUSB_HOST
case USB_DR_MODE_HOST:
pdata.mode = MUSB_HOST;
glue->phy_mode = PHY_MODE_USB_HOST;
break;
#endif
#if defined CONFIG_USB_MUSB_DUAL_ROLE || defined CONFIG_USB_MUSB_GADGET
case USB_DR_MODE_PERIPHERAL:
pdata.mode = MUSB_PERIPHERAL;
glue->phy_mode = PHY_MODE_USB_DEVICE;
break;
#endif
#ifdef CONFIG_USB_MUSB_DUAL_ROLE
case USB_DR_MODE_OTG:
pdata.mode = MUSB_OTG;
glue->phy_mode = PHY_MODE_USB_OTG;
break;
#endif
default:
dev_err(&pdev->dev, "Invalid or missing 'dr_mode' property\n");
return -EINVAL;
}
pdata.platform_ops = &sunxi_musb_ops;
if (!of_device_is_compatible(np, "allwinner,sun8i-h3-musb"))
pdata.config = &sunxi_musb_hdrc_config;
else
pdata.config = &sunxi_musb_hdrc_config_h3;

glue->dev = &pdev->dev;  
INIT\_WORK(&glue->work, sunxi\_musb\_work);  
glue->host\_nb.notifier\_call = sunxi\_musb\_host\_notifier;

if (of\_device\_is\_compatible(np, "allwinner,sun4i-a10-musb")||  
    of\_device\_is\_compatible(np, "allwinner,suniv-musb")){ //新增判断项代码  
    set\_bit(SUNXI\_MUSB\_FL\_HAS\_SRAM, &glue->flags);  
}  
if (of\_device\_is\_compatible(np, "allwinner,sun6i-a31-musb"))  
    set\_bit(SUNXI\_MUSB\_FL\_HAS\_RESET, &glue->flags);

if (of\_device\_is\_compatible(np, "allwinner,sun8i-a33-musb") ||  
    of\_device\_is\_compatible(np, "allwinner,sun8i-h3-musb") ||  
    of\_device\_is\_compatible(np, "allwinner,suniv-musb")) {  //新增判断项代码  
    set\_bit(SUNXI\_MUSB\_FL\_HAS\_RESET, &glue->flags);  
    set\_bit(SUNXI\_MUSB\_FL\_NO\_CONFIGDATA, &glue->flags);  
}

glue->clk = devm\_clk\_get(&pdev->dev, NULL);  
if (IS\_ERR(glue->clk)) {  
    dev\_err(&pdev->dev, "Error getting clock: %ld\\n",  
        PTR\_ERR(glue->clk));  
    return PTR\_ERR(glue->clk);  
}

if (test\_bit(SUNXI\_MUSB\_FL\_HAS\_RESET, &glue->flags)) {  
    glue->rst = devm\_reset\_control\_get(&pdev->dev, NULL);  
    if (IS\_ERR(glue->rst)) {  
        if (PTR\_ERR(glue->rst) == -EPROBE\_DEFER)  
            return -EPROBE\_DEFER;  
        dev\_err(&pdev->dev, "Error getting reset %ld\\n",  
            PTR\_ERR(glue->rst));  
        return PTR\_ERR(glue->rst);  
    }  
}

…………

static const struct of_device_id sunxi_musb_match[] = {
{ .compatible = "allwinner,suniv-musb", }, //新增代码
{ .compatible = "allwinner,sun4i-a10-musb", },
{ .compatible = "allwinner,sun6i-a31-musb", },
{ .compatible = "allwinner,sun8i-a33-musb", },
{ .compatible = "allwinner,sun8i-h3-musb", },
{}
};

2.5 通过menuconfig配置usb相关的选项

进入：Device Drivers - USB support

进行配置，当然可以根据自己实际情况进行开启与配置。

接下载编译Linux编译内核和设备树，就可以得到内核文件和设备树文件了。

这里我默认设置开发板为host模式，然后我要通过usb连接键盘进行输入操作：

[ 31.653231] cfg80211: failed to load regulatory.db
[ 31.696053] EXT4-fs (mmcblk0p2): mounted filesystem with ordered data mode. Opts: (null)
[ 31.707915] VFS: Mounted root (ext4 filesystem) on device 179:2.
[ 31.726584] devtmpfs: mounted
[ 31.736031] Freeing unused kernel memory: 1024K
[ 31.746083] Run /sbin/init as init process
[ 32.023410] usb 1-1: new high-speed USB device number 2 using musb-hdrc
[ 32.215728] hub 1-1:1.0: USB hub found
[ 32.221496] hub 1-1:1.0: 4 ports detected

启动日志中我们可以看到usb已经被检测到，并且检测到4个端口，但是我们只用到两个。

插入键盘。

拔出键盘。

键盘操作开发板：

如果想要进一步了解usb相关的操作，可以借助usbutils相关组件。

首先安装usbutils组件

apt-get install usbutils

安装完成后执行：

lsusb

就可以查看相关usb设备信息了。

首先更改设备树，改为otg模式

&usb_otg {
dr_mode = "otg"; /* 三个可选项: otg / host / peripheral */
status = "okay";
};

进入Linux系统,执行,usb将会被设置成为host模式

echo host > /sys/devices/platform/soc/1c13000.usb/musb-hdrc.1.auto/mode

运行结果如下，此时可以插入键盘，就可以使用键盘操作Linux了。

# echo host > /sys/devices/platform/soc/1c13000.usb/musb-hdrc.1.auto/mode

[117.758152] phy phy-1c13400.phy.0: Changing dr_mode to 1

[ 118.414817] usb 1-1: new high-speed USB device number 3 using musb-hdrc
[ 118.598193] usb-storage 1-1:1.0: USB Mass Storage device detected
[ 118.611789] scsi host0: usb-storage 1-1:1.0
[ 119.686198] scsi 0:0:0:0: Direct-Access Mass Storage Device 1.00 PQ: 0 ANSI: 0 CCS
[ 119.703976] sd 0:0:0:0: [sda] 3842048 512-byte logical blocks: (1.97 GB/1.83 GiB)
[ 119.725260] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 119.739844] sd 0:0:0:0: [sda] Write Protect is off
[ 119.771819] sd 0:0:0:0: [sda] No Caching mode page found
[ 119.777288] sd 0:0:0:0: [sda] Assuming drive cache: write through
[ 119.801571] sda: sda1 sda2 sda3
[ 119.817224] sd 0:0:0:0: [sda] Attached SCSI removable disk

如果执行如下命令，则进入设备模式

##切换到device模式: