通过在位修改指令中使用屏蔽字节,可以精确地指定要修改的寄存器位,而不会影响其他位的内容。 MCP2515支持位修改指令和屏蔽字节,MCP2515的SPI指令表如下所示: 位修改指令格式如下所示: CS片选信号拉低之后依次向MCP2515发送位修改命令字节、寄存器地址、屏蔽字节以及数据字节。 屏蔽字节确定允许修改寄存器中的哪一位。屏蔽...
在应用程序中可以通过ioctl来获取和配置SPI的相关属性,并实现SPI数据的发送和接收,SPI的ioctl宏定义在“/usr/include/linux/spi/spidev.h”,部分ioctl cmd如下所示: /* 读取 / 写入 SPI 模式(SPI_MODE_0..SPI_MODE_3)(限制为 8 位) */ #define SPI_IOC_RD_MODE _IOR(SPI_IOC_MAGIC, 1, __u8) /...
spi-max-frequency = <24000000>;/* 选择引脚GPIO4_C4 默认状态下是高电平 */ cs-gpio = <&gpio...
> CAN Device Drivers > CAN SPI interfaces <*> Microchip MCP251x and MCP25625 SPI CAN controllers 然后在kernel/arch/arm64/boot/dts/rockchip/rk3568-evb1-ddr4-v10.dtsi设备树中添加如下节点: &spi0 { status = "okay"; pinctrl-0 = <&spi0m1_cs0 &spi0m1_pins>; pinctrl-1 = <&spi0m1...
pinctrl-1 = <&spi0m1_cs0 &spi0m1_pins_hs>; mcp2515: mcp2515@0 { compatible = "microchip,mcp2515"; reg = <0>; spi-max-frequency = <10000000>; interrupt-parent = <&gpio0>; interrupts = ; pinctrl-names = "default"; pinctrl-0 = <&mcp2515_int>; ...
> CAN SPI interfaces <*> Microchip MCP251x and MCP25625 SPI CAN controllers 然后在kernel/arch/arm64/boot/dts/rockchip/rk3568-evb1-ddr4-v10.dtsi设备树中添加如下节点: &spi0 { status = "okay"; pinctrl-0 = <&spi0m1_cs0 &spi0m1_pins>; ...
cs-gpios = <&gpio1 RK_PB2_GPIO_ACTIVE_LOW>; num-chipselects = <1>; pinctrl-names = "default"; pinctrl-0 = <&spi5_gpios>; status = "disabled"; }; 然后对pinctrl节点进行追加,追加内容如下所示: spi5_gpios: gpios { rockchip,pins = <0 RK_PB0 0 &pcfg_pull_none>, ...
78 GMAC0_INT/PMEB_GPIO2_D2 GPOP(风扇控制) LCDC_D2/VOP_BT656_D2_M0/SPI0_CS0_M1/PCIE30X1_CLKREQn_M1/I2S1_LRCK_TX_M2/ GPIO2_D2_d 79 GMAC0_RSTn_GPIO2_D3 GPIO(GMAC0复位) LCDC_D3/VOP_BT656_D3_M0/SPI0_CLK_M1/PCIE30X1_WAKEn_M1/I2S1_SDI0_M2/GPIO2_D3_d 80 GND 电源...
PIN 16 SPI0_MOSI 输入输出 3V3 SPI接口 GPIO PIN 17 SPI0_MISO 输入输出 3V3 SPI接口 GPIO PIN 18 SPI0_CS0 输入输出 3V3 SPI接口 GPIO PIN 19 ADC0 输入 1V8 ADC模拟输入 PIN 20 ADC1 输入 1V8 Loard 按键 PIN 21 EMMC_KEY 输入 1V8 升级键 PIN 22 RST_KEY 输入 1V8 复位键 PIN 23...
cs-gpios = <&gpio1 RK_PB2_GPIO_ACTIVE_LOW>; num-chipselects = <1>; pinctrl-names = "default"; pinctrl-0 = <&spi5_gpios>; status = "disabled"; }; 然后对pinctrl节点进行追加,追加内容如下所示: spi5_gpios: gpios { rockchip,pins = <0 RK_PB0 0 &pcfg_pull_none>, ...