一:加载wifi驱动模块
在hardware/libhardware_legacy/wifi/wifi.c调用函数
insmod(DRIVER_MODULE_PATH, DRIVER_MODULE_ARG)
其中
DRIVER_MODULE_PATH = /system/lib/dhd.ko
DRIVER_MODULE_ARG = "firmware_path=/etc/wifi/40181/fw_bcm40181a2.bin nvram_path=/etc/wifi/40181/nvram.txt"
二:wifi驱动模块运行
wifi驱动入口dhd_module_init(void) dhd_linux.c
dhd_module_init(void) { int error = 0; DHD_TRACE(("%s: Enter\n", __FUNCTION__)); wl_android_init(); //初始化dhd_msg_level |= DHD_ERROR_VAL,给iface_name赋值为wlan do { sema_init(&dhd_chipup_sem, 0); dhd_bus_reg_sdio_notify(&dhd_chipup_sem); //注册sdio driver,支持如下图wifi列表,sdio驱动获取wifi列表的设备后调用 //dummy_probe() --> up(dhd_chipup_sem); dhd_customer_gpio_wlan_ctrl(WLAN_POWER_ON); if (down_timeout(&dhd_chipup_sem, //2000ms超时等待dhd_chipup_sem msecs_to_jiffies(POWERUP_WAIT_MS)) == 0) { dhd_bus_unreg_sdio_notify(); chip_up = 1; break; } DHD_ERROR(("\nfailed to power up wifi chip, retry again (%d left) **\n\n", retry+1)); dhd_bus_unreg_sdio_notify(); dhd_customer_gpio_wlan_ctrl(WLAN_POWER_OFF); } while (retry-- > 0); if (!chip_up) { DHD_ERROR(("\nfailed to power up wifi chip, max retry reached, exits **\n\n")); return -ENODEV; } sema_init(&dhd_registration_sem, 0); error = dhd_bus_register(); //注册dhd_sdio驱动,最终会调用到dhd_net_attach(); if (!error) printf("\n%s\n", dhd_version); else { DHD_ERROR(("%s: sdio_register_driver failed\n", __FUNCTION__)); goto fail_1; } /* * Wait till MMC sdio_register_driver callback called and made driver attach. * It‘s needed to make sync up exit from dhd insmod and * Kernel MMC sdio device callback registration */ if ((down_timeout(&dhd_registration_sem, //函数dhd_net_attach() --> up(&dhd_registration_sem); msecs_to_jiffies(DHD_REGISTRATION_TIMEOUT)) != 0) || (dhd_registration_check != TRUE)) { error = -ENODEV; DHD_ERROR(("%s: sdio_register_driver timeout or error \n", __FUNCTION__)); goto fail_2; } wl_android_post_init(); return error; fail_2: dhd_bus_unregister(); fail_1: /* Call customer gpio to turn off power with WL_REG_ON signal */ dhd_customer_gpio_wlan_ctrl(WLAN_POWER_OFF); return error; }
原文:http://blog.csdn.net/enson16855/article/details/25284437