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文章目录
- 动手写驱动之前的思考
- MAC驱动兼容不同的MPU平台
- 解决不同MPU平台头文件包含的问题
- 对MAC操作接口的抽象
- 对MAC设备的抽象
- MAC设备的注册
这是个人驱动开发过程中做的一些记录，仅代表个人意见和理解，不喜勿喷
动手写驱动之前的思考
- MAC驱动需要兼容不同的MPU平台
- MAC驱动需要支持不同的PHY芯片
- MAC驱动需要支持多个以太网接口
- MAC驱动需要是否借鉴某个平台代码
在动手写驱动之前，脑海里就会在不停地思考这几个问题，等脑子里有个大概的可行框架就开始动手码代码。
MAC驱动兼容不同的MPU平台
Microchip 也有着丰富的MPU产品线(通过收购Atmel而获取)，覆盖传统的ARM9、Cortex-A5和Cortex-A7内核。有的MPU它的以太网叫做GMAC，而有的又叫做EMAC，那编写驱动的时候就要留意对GMAC
解决不同MPU平台头文件包含的问题
选择在libraries/Kconfig文件下添加以下内容：
config SOC_SAM9X60_EKboolselect RT_USING_COMPONENTS_INITselect RT_USING_CACHEconfig SOC_SAM9X75_EKboolselect RT_USING_COMPONENTS_INITselect RT_USING_CACHEconfig SOC_SAMA5D2_XULTboolselect ARCH_ARM_CORTEX_Aselect ARCH_ARM_CORTEX_FPUconfig SOC_SAMA5D2_SOM1_EKboolselect ARCH_ARM_CORTEX_Aselect ARCH_ARM_CORTEX_FPUconfig SOC_SAMA7G54_EKboolselect ARCH_ARM_CORTEX_Aselect ARCH_ARM_CORTEX_FPU
那在sam9x75-ek/board/Kconfig文件下这么做：
menu "Microchip Harmony Plib Configuration"config SOC_SAM9X75boolselect ARCH_ARM_ARM9select SOC_SAM9X75_EKselect RT_USING_USER_MAINdefault y
通过这样的方式，在选择sam9x75-ek平台做开发的时候，就会自动选择上SOC_SAM9X75_EK这个宏定义，后面会用到这个定义。
接下来在gmac/hpl_mac_async.h头文件中添加以下代码实现了对不同平台头文件的包含：
#ifdef SOC_SAMA5D2
#include <sama5d27.h>
#endif#ifdef SOC_SAM9X75
#include <sam9x75.h>
#endif#ifdef SOC_SAMA7G54
#include <sama7g54.h>
#endif
有的MPU平台只有一个GMAC，那它给的MAC相关ID定义是ID_GMAC，如果包含2个GMAC的MPU平台，则会给出ID_GMAC0和ID_GMAC1，那我选择在hpl_mac_async.h头文件添加这样的定义（后面会讲解到这样定义的作用）：
#define ID_GMAC_NONE 0xFF#ifdef ID_GMAC
# define MAC0_ID ID_GMAC
# define MAC1_ID ID_GMAC_NONE
# define MAC0_IRQn GMAC_IRQn
# define MAC1_IRQn ID_GMAC_NONE
# define MAC0_REGS GMAC_REGS
# define MAC1_REGS (void *)0
#else
# define MAC0_ID ID_GMAC0
# define MAC1_ID ID_GMAC1
# define MAC0_IRQn GMAC0_IRQn
# define MAC1_IRQn GMAC1_IRQn
# define MAC0_REGS GMAC0_REGS
# define MAC1_REGS GMAC1_REGS
#endif
对MAC操作接口的抽象
MAC操作接口的抽象，包括中断处理函数、初始化、使能和禁止、网络数据包的收发、获取接收数据包长度、过滤的设置、MAC地址的设置和非常重要的PHY读写访问接口：
struct h3_macplib_ops
{void (*macdev_interrupt)(mac_dev *const dev);int32_t (*macdev_init)(mac_dev *const dev, void *const hw);int32_t (*macdev_deinit)(mac_dev *const dev);int32_t (*macdev_enable)(mac_dev *const dev);int32_t (*macdev_disable)(mac_dev *const dev);int32_t (*macdev_send)(mac_dev *const dev, uint8_t *buf, uint32_t len);uint32_t (*macdev_recv)(mac_dev *const dev, uint8_t *buf, uint32_t len);uint32_t (*macdev_rxbyte)(mac_dev *const dev);int32_t (*macdev_register)(mac_dev *const dev, mac_cb_type type, mac_async_cb fn);int32_t (*macdev_filter)(mac_dev *const dev, uint8_t index, mac_filter *filter);int32_t (*macdev_setmac)(mac_dev *const dev, uint8_t mac[6]);int32_t (*macdev_writephy)(mac_dev *const dev, uint16_t addr, uint16_t reg, uint16_t data);int32_t (*macdev_readphy) (mac_dev *const dev, uint16_t addr, uint16_t reg, uint16_t *val);
};
对MAC设备的抽象
对MAC设备也做出了抽象，MPU中如果存在多个MAC接口，那就会有对应数量的MAC设备实例：
struct h3_macplib_dev
{const char *name;IRQn_Type irqnum;H3_MAC_REGS regs;uint8_t mac_addr[6];uint8_t dev_id;uint8_t reserved;mac_async_dev mac_dev;phy_async_dev phy_dev;const struct rt_mdio_bus_ops *mdio_ops;const struct h3_macplib_ops *mac_ops;struct rt_mdio_bus rt_mdiobus;struct eth_device rt_ethdev;
};
MAC设备的注册
对MAC设备对应的实例，其部分成员都会在h3_macplib.c文件里面做静态的初始化：
#if defined(BSP_USING_GMAC0) || defined(BSP_USING_EMAC0)
struct h3_macplib_dev h3_macdev0 = {.name = "e0",.irqnum = MAC0_IRQn,.regs = MAC0_REGS,.dev_id = MAC0_ID,.mac_ops = &h3_macdev_ops,
};
#endif#if defined(BSP_USING_GMAC1) || defined(BSP_USING_EMAC1)
struct h3_macplib_dev h3_macdev1 = {.name = "e1",.irqnum = MAC1_IRQn,.regs = MAC1_REGS,.dev_id = MAC1_ID,.mac_ops = &h3_macdev_ops,
};
#endif
实现对多个MAC设备的注册是这样来实现的：
static struct h3_macplib_dev *h3_macplib_devtable[] =
{0
#if defined(BSP_USING_GMAC0) || defined(BSP_USING_EMAC0), &h3_macdev0
#endif
#if defined(BSP_USING_GMAC1) || defined(BSP_USING_EMAC1), &h3_macdev1
#endif
};
int h3_macplib_init(void)
{rt_err_t state;uint8_t macaddr = 0xAA;uint32_t table_sz = sizeof(h3_macplib_devtable)/sizeof(uint32_t);struct h3_macplib_dev *macplib_dev;for (uint32_t i = 1; i < table_sz; i++){macplib_dev = h3_macplib_devtable[i];macplib_dev->mac_dev.devid = macplib_dev->dev_id;macplib_dev->rt_mdiobus.hw_obj = (void *)macplib_dev;macplib_dev->rt_mdiobus.ops = &h3_mdiobus_ops;/* GMAC MAC Address */macplib_dev->mac_addr[0] = 0x54;macplib_dev->mac_addr[1] = 0x27;macplib_dev->mac_addr[2] = 0x8d;macplib_dev->mac_addr[3] = 0x33;macplib_dev->mac_addr[4] = 0x55;macplib_dev->mac_addr[5] = macaddr++;macplib_dev->rt_ethdev.parent.init = h3_macplib_initial;macplib_dev->rt_ethdev.parent.open = h3_macplib_open;macplib_dev->rt_ethdev.parent.close = h3_macplib_close;macplib_dev->rt_ethdev.parent.read = h3_macplib_read;macplib_dev->rt_ethdev.parent.write = h3_macplib_write;macplib_dev->rt_ethdev.parent.control = h3_macplib_control;macplib_dev->rt_ethdev.parent.user_data = (void *)macplib_dev;macplib_dev->rt_ethdev.eth_rx = h3_macplib_rx;macplib_dev->rt_ethdev.eth_tx = h3_macplib_tx;/* register eth device */state = eth_device_init(&macplib_dev->rt_ethdev, macplib_dev->name);if (RT_EOK != state) {break;}eth_device_linkchange(&macplib_dev->rt_ethdev, RT_FALSE);}return state;
}
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