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发表于 2018-8-22 10:29:30
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在3399上的wifi信号比较差,想改信号强度,但sdio的dts配置中没有相关描述只看到emmc的信息。
《Rockchip RK3399 TRM V1.4 Part2-20170408.pdf》里的emmc host controller章节有如下描述:
The ‘phyctrl_dr_ty[2:0]’ are used to program the drive strength of the IO in push/pull
mode of operation by programming the source/sink impedance of EMMC51 IO. The PAD
source/sink impedance can be programmed to 50, 33, 66, 100 or 40 Ohms
在drivers/phy/phy-rockchiop-emmc.c文件中有
68 #define PHYCTRL_DR_50OHM 0x0
69 #define PHYCTRL_DR_33OHM 0x1
70 #define PHYCTRL_DR_66OHM 0x2
71 #define PHYCTRL_DR_100OHM 0x3
72 #define PHYCTRL_DR_40OHM 0x4
/* Drive impedance: 50 Ohm */ 292 regmap_write(rk_phy->reg_base, 293 rk_phy->reg_offset + GRF_EMMCPHY_CON6, 294 HIWORD_UPDATE(PHYCTRL_DR_50OHM, 295 PHYCTRL_DR_MASK, 296 PHYCTRL_DR_SHIFT));更改PHYCTRL_DR_50OHM > PHYCTRL_DR_100OHM
但发现sdio0的驱动强度没有改变 ,请问这里的drive strength是指什么意思?
硬件sdio0接到wifi网卡,这里也没有看到改的是哪一路sdio,如果我想要改sdio0的驱动强度应该怎么改呢?
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