我們對(duì)g_ethercat_ssc_port0_ext_cfg這個(gè)全局變量深入追蹤，其成員變量 g_ether_PHY0，正好是一個(gè)PHY實(shí)例的詳細(xì)描述體。

/* Instance structure to use this module. */
const ether_PHY_instance_t g_ether_PHY0 =
{
  .p_ctrl    = &g_ether_PHY0_ctrl,
  .p_cfg     = &g_ether_PHY0_cfg,
  .p_api     = &g_ether_PHY_on_ether_PHY
};

其中g(shù)_ether_PHY0_cfg是pyh實(shí)例的配置結(jié)構(gòu)體：

const ether_PHY_cfg_t g_ether_PHY0_cfg =
{


  .channel          = 0,
  .PHY_lsi_address      = 0,
  .PHY_reset_wait_time    = 0x00020000,
  .mii_bit_access_wait_time = 0,             // Unused
  .flow_control       = ETHER_PHY_FLOW_CONTROL_DISABLE,
  .mii_type         = (ether_PHY_mii_type_t) 0, // Unused
  .p_context         = NULL,
  .p_extend         = &g_ether_PHY0_extend
};

這里又通過p_extend 做了擴(kuò)展配置（其實(shí)可以合并在一起）如下所示：

const ether_PHY_extend_cfg_t g_ether_PHY0_extend =
{
  .port_type     = ETHER_PHY_PORT_TYPE_ETHER_CAT,
  .PHY_chip      = (ether_PHY_chip_t) ETHER_PHY_CHIP_VSC8541,
  .mdio_type     = ETHER_PHY_MDIO_GMAC,


  .bps        = ETHER_PHY_SPEED_100,
  .duplex       = ETHER_PHY_DUPLEX_FULL,
  .auto_negotiation  = ETHER_PHY_AUTO_NEGOTIATION_ON,


  .PHY_reset_pin   = BSP_IO_PORT_20_PIN_7,
  .PHY_reset_time   = 15000,


  .p_selector_instance = (ether_selector_instance_t *)&g_ether_selector0,
};

可以看到上面的擴(kuò)展配置當(dāng)中，PHY的具體硬件型號(hào)都已經(jīng)列出，如PHY_chip = (ether_PHY_chip_t) ETHER_PHY_CHIP_;

可以看到在示例代碼當(dāng)中已經(jīng)支持的PHY如下所示：

/** Identify PHY-LSI */
typedef enum e_ether_PHY_chip
{
  ETHER_PHY_CHIP_VSC8541 = (1 << 0), ///< VSC8541
 ? ?ETHER_PHY_CHIP_KSZ9131 = (1 << 1), ///< KSZ9131
 ? ?ETHER_PHY_CHIP_KSZ9031 = (1 << 2), ///< KSZ9031
 ? ?ETHER_PHY_CHIP_KSZ8081 = (1 << 3), ///< KSZ8081
 ? ?ETHER_PHY_CHIP_KSZ8041 = (1 << 4) ?///< KSZ8041
} ether_PHY_chip_t;

這里具體看一下 g_ether_selector0 這個(gè) ether_selector_instance_t 類型的全局指針，指向 selector driver實(shí)例的成員變量：

typedef struct st_ether_selector_instance
{
  ether_selector_ctrl_t   * p_ctrl; ///< Pointer to the control structure for this instance
 ? ?ether_selector_cfg_t const * p_cfg; ?///< Pointer to the configuration structure for this instance
 ? ?ether_selector_api_t const * p_api; ?///< Pointer to the API structure for this instance
} ether_selector_instance_t;

這又是一個(gè)類似的結(jié)構(gòu)體，通過三個(gè)指針來分別指向結(jié)構(gòu)本身，selector的具體配置，和配置selector過程中所需要用的的成員方法api.

看一下selector的具體配置信息：

typedef struct st_ether_selector_cfg
{
  uint8_t port;               ///< Port number
 ? ?ether_selector_PHYlink_polarity_t PHYlink; ///< PHY link signal polarity


 ? ?ether_selector_interface_t interface; ? ? ?///< Converter mode
 ? ?ether_selector_speed_t ? ? speed; ? ? ? ? ?///< Converter Speed
 ? ?ether_selector_duplex_t ? ?duplex; ? ? ? ? ///< Converter Duplex
 ? ?ether_selector_ref_clock_t ref_clock; ? ? ?///< Converter REF_CLK
 ? ?void const ? ? ? ? ? ? ? * p_extend; ? ? ? ///< Placeholder for user extension.
} ether_selector_cfg_t;

可以看到selector 對(duì)應(yīng)的端口號(hào)，PHY連接信號(hào)對(duì)應(yīng)的極性，接口模式，速率，全雙工，以及外部時(shí)鐘輸入。再看一下配置selector的過程中所需要用到的API函數(shù)：

const ether_selector_api_t g_ether_selector_on_ether_selector =
{
  .open     = R_ETHER_SELECTOR_Open,
  .converterSet = R_ETHER_SELECTOR_ConverterSet,
  .close    = R_ETHER_SELECTOR_Close,
  .versionGet  = R_ETHER_SELECTOR_VersionGet
};

其最主要的成員方法就是R_ETHER_SELECTOR_Open做了些什么：

先初始化ETHER_SELECTOR

 /* One time initialization for all ETHER_SELECTOR instances. */
  r_ether_selector_state_initialize();


  /* Unlock write access protection for Ethernet subsystem registers */
  r_ether_selector_reg_protection_disable(p_reg_ethss);
  
  /* Set the function of Ethernet ports. */
  sw_mode = ETHER_SELECTOR_CFG_MODE;
  p_reg_ethss->MODCTRL_b.SW_MODE = sw_mode & ETHER_SELECTOR_MODCTRL_BIT_SWMODE_MASK;
  
  /* Set the MAC of all port for half-duplex. */
  p_reg_ethss->SWDUPC_b.PHY_DUPLEX = 0;
  
  /* Set all Ethernet switch port to select not use 10Mbps. */
  p_reg_ethss->SWCTRL_b.SET10 = 0;

根據(jù)端口號(hào)來選擇對(duì)應(yīng)控制寄存器

/* Set RGMII/RMII Converter configuration */
  switch (port)
  {
    case 0:
    {
      p_reg_convctrl = (uint32_t *) &p_reg_ethss->CONVCTRL[0];
      break;
    }


    case 1:
    {
      p_reg_convctrl = (uint32_t *) &p_reg_ethss->CONVCTRL[1];
      break;
    }


    case 2:
    default:
    {
      p_reg_convctrl = (uint32_t *) &p_reg_ethss->CONVCTRL[2];
      break;
    }
  }

根據(jù)指向selector的配置信息：

const ether_selector_cfg_t g_ether_selector0_cfg =
{
  .port           = 0,
  .PHYlink          = ETHER_SELECTOR_PHYLINK_POLARITY_LOW,
  .interface         = ETHER_SELECTOR_INTERFACE_RGMII,
  .speed           = ETHER_SELECTOR_SPEED_100MBPS,
  .duplex          = ETHER_SELECTOR_DUPLEX_FULL,
  .ref_clock         = ETHER_SELECTOR_REF_CLOCK_INPUT,
  .p_extend         = NULL,
};

來對(duì)CONVCTRL[port_number]寄存器做相應(yīng)的配置

這里結(jié)合RZ/T2M的用戶手冊(cè)，很容易理解其中的意思：

結(jié)合代碼來看，總體ETHER_SELECTOR 的驅(qū)動(dòng)的配置流程圖臺(tái)下所示：

在對(duì)ETHER_SELECTOR驅(qū)動(dòng)做完配置后，下面具體看一下對(duì)ETHER_PHY_CHIP這個(gè)PHY，代碼具體做了哪些操作：

首先是做初始化：

oid ether_PHY_targets_initialize_vsc8541 (ether_PHY_instance_ctrl_t * p_instance_ctrl)
{
  /* Vendor Specific PHY Registers */
 #define ETHER_PHY_REG_LED_MODE_SELECT         (0x1D)
 #define ETHER_PHY_REG_LED_BEHAVIOR          (0x1E)
 #define ETHER_PHY_REG_EXTEND_GPIO_PAGE        (0x1F)
...

這個(gè)初始化函數(shù)，并沒有對(duì)IEEE 標(biāo)準(zhǔn)規(guī)定的16個(gè)寄存器做讀寫操作，只對(duì)廠商自定義的寄存器做了配置。初始化完成之后，對(duì)是否打開自動(dòng)協(xié)商的功能對(duì)PHY進(jìn)行了讀寫：

這里可以看到對(duì)PHY芯生來說，需要配置的寄存器并不是很多，大多數(shù)情況下，把自動(dòng)協(xié)商寄存器配置好，就可以了。除此之后就是廠商自定義的寄存器的一些自定義的功能。這部分功能需要結(jié)合用戶手冊(cè)來理解和使用，大部分也是用來調(diào)試和指示的作用以及一些IEEE基本標(biāo)準(zhǔn)之外的特色功能，比如節(jié)能標(biāo)準(zhǔn)之類的。

對(duì)于用戶說來，搞清楚數(shù)據(jù)結(jié)構(gòu)之間的關(guān)聯(lián)，剩下的就是驅(qū)動(dòng)代碼的執(zhí)行邏輯，考慮到執(zhí)行邏輯并不復(fù)雜，這里不展開來說。用戶可以參考錄屏材料進(jìn)一步深入了解。

其它

經(jīng)過驗(yàn)證的PHY芯片列表：

審核編輯：劉清