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rk3568 phy驱动调式_phy寄存器

news 来源：原创 2025/5/10 21:54:19

1，phy调式相关寄存器

root@ubuntu2004:~# cat /sys/bus/mdio_bus/devices/stmmac-0\:00/phy_id
0x001cc916
root@ubuntu2004:~# cat /sys/bus/mdio_bus/devices/stmmac-0\:00/phy_interface
rgmii

root@ubuntu2004:~# cat /sys/bus/mdio_bus/devices/stmmac-0\:00/phy_registers
0: 0x1040
1: 0x79ad
2: 0x1c
3: 0xc916
4: 0xde1
5: 0xcde1
6: 0x6f
7: 0x2801
8: 0x5282
9: 0x200
10: 0x0
11: 0x0
12: 0x0
13: 0x4003
14: 0x400
15: 0x2000
16: 0x23
17: 0x0
18: 0x0
19: 0x0
20: 0x0
21: 0xe00
22: 0xf00
23: 0xf00
24: 0x311e
25: 0x863
26: 0x31dc
27: 0x2
28: 0x0
29: 0x0
30: 0x0
31: 0xa42

写寄存器：

root@ubuntu2004:~# echo 00 abcd > /sys/bus/mdio_bus/devices/stmmac-0:00/phy_registers
bash: /sys/bus/mdio_bus/devices/stmmac-0:00/phy_registers : Permission denied

查看权限后修改权限：

root@ubuntu2004:/sys/bus/mdio_bus/devices/stmmac-0:00# chmod 777 phy_registers
root@ubuntu2004:/sys/bus/mdio_bus/devices/stmmac-0:00# ls -al
-rwxrwxrwx 1 root root 4096 Mar 2 21:06 phy_registers

写测试：

root@untu2004:/sys/bus/mdio_bus/devices/stmmac-0:00# echo 0x00 0x1140 > phy_registers
root@ubuntu2004:/sys/bus/mdio_bus/devices/stmmac-0:00#
root@ubuntu2004:/sys/bus/mdio_bus/devices/stmmac-0:00# cat phy_registers
0: 0x1140
1: 0x7989

2，代码分析：rk3568\rk356x-linux\kernel\drivers\net\phy\phy_device.c

读寄存器：

static ssize_t phy_registers_show(struct device *dev, struct device_attribute *attr, char *buf)
{
   struct phy_device *phydev = to_phy_device(dev);
   int index;

   for (index = 0; index < 32; index++)
       sprintf(buf, "%s%2d: 0x%x\n", buf, index,
           phy_read(phydev, index));

   return strlen(buf);
}

写寄存器

static ssize_t phy_registers_store(struct device *dev, struct device_attribute *attr,
       const char *buf, size_t count){
   struct phy_device *phydev = to_phy_device(dev);
   int index = 0, val = 0;
   char tmp[32];
   char *data;

   if (count >= sizeof(tmp))
       goto out;

   memset(tmp, 0, sizeof(tmp));
   memcpy(tmp, buf, count);

   data = tmp;
   data = strstr(data, " ");
   if (!data)
       goto out;
   *data = 0;
   data++;

   if (kstrtoint(tmp, 0, &index) || index >= 32)
       goto out;

   if (kstrtoint(data, 0, &val) || val > 0xffff)
       goto out;

   pr_info("Set Ethernet PHY register %d to 0x%x\n", (int)index, (int)val);

   phy_write(phydev, index, val);

   return count;

out:
   pr_err("wrong register value input\n");
   pr_err("usage: <reg index> <value>\n");

   return count;
}

查看调用sysfs调用过程

static DEVICE_ATTR_RW(phy_registers);

#define DEVICE_ATTR_RW(_name) \
struct device_attribute dev_attr_##_name = __ATTR_RW(_name)

#define __ATTR_RW(_name) __ATTR(_name, 0644, _name##_show, _name##_store)

sys/bus/mdio_bus/devices/stmmac-0\:00/里面的 phy_registers。

device_attribute描述phy_registers的属性，而他有show和store两种操作（读和写）。

/* interface for exporting device attributes */
struct device_attribute {
   struct attribute   attr;
   ssize_t (*show)(struct device *dev, struct device_attribute *attr, char *buf);
   ssize_t (*store)(struct device *dev, struct device_attribute *attr, const char *buf, size_t count);
};