浅谈如何获得设备驱动.md

浅谈如何获得设备驱动

1. 设备树, 记得u-boot和Linux内核的设备树要结合起来一起看。或者直接从设备上已运行的Linux中获得。

   在uboot设备树提到了:

   sdio1: sdio1@16020000 {
   			compatible = "snps,dw-mshc";
   			reg = <0x0 0x16020000 0x0 0x10000>;
   			clocks = <&clkgen JH7110_SDIO1_CLK_AHB>,
   				 <&clkgen JH7110_SDIO1_CLK_SDCARD>;
   			clock-names = "biu","ciu";
   			resets = <&rstgen RSTN_U1_DW_SDIO_AHB>;
   			reset-names = "reset";
   		};
   

   所以可以在drivers/mmc/snps_dw_mmc.c 这里找到:

   struct dm_mmc_ops snps_dwmci_dm_ops;
   
   static int snps_dwmmc_probe(struct udevice *dev)
   {
   #ifdef CONFIG_BLK
   	struct snps_dwmci_plat *plat = dev_get_plat(dev);
   #endif
   	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
   	struct snps_dwmci_priv_data *priv = dev_get_priv(dev);
   	struct dwmci_host *host = &priv->host;
   	unsigned int clock_max;
   	int ret;
   
   	/* Extend generic 'dm_dwmci_ops' with our 'getcd' implementation */
   	memcpy(&snps_dwmci_dm_ops, &dm_dwmci_ops, sizeof(struct dm_mmc_ops));
   	snps_dwmci_dm_ops.get_cd = snps_dwmmc_getcd;

   所以在drivers/mmc/dw_mmc.c 这里有代码。

   之后就交给GPT好了

2. defconfig

   从这里 configs/starfive_visionfive2_defconfig也能看到:

   ONFIG_MMC_DW=y
   CONFIG_MMC_DW_SNPS=y