Difference between revisions of "SPI"
From FriendlyELEC WiKi
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| − | + | 开发人员可以自行修改和编译dts文件将其使能，也可以通过[[npi-config]]快速地将其使能，如下: | |
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$ npi-config | $ npi-config | ||
Revision as of 01:57, 18 January 2019
Contents
1 S5P4418
1.1 Q: S5P4418的/dev目录下只有一个spidev0.0这个设备节点, 怎么添加spidev1.0
对于3.4内核来说，4418 需要修改 arch/arm/plat-s5p4418/nanopi2/device.c;
想要增加一路的话，可先搜索 CONFIG_SPI_SPIDEV , 然后参考已有代码增加另一路的支持;
另外，arch/arm/plat-s5p4418/asb/device.c 有 spi2 的支持，修改时可参考;
2 H5
2.1 SPI Flash
FriendlyElec H5的Linux-4.14内核集成了"mxicy,mx25l12805d"的SPI Flash驱动，使用的是SPI0，但是默认并没有使能，相关的dts配置如下:
$ cat linux/arch/arm64/boot/dts/allwinner/sun50i-h5-nanopi.dtsi
&spi0 {
...
spiflash: spiflash@0 {
#address-cells = <1>;
#size-cells = <1>;
compatible = "mxicy,mx25l12805d";
reg = <0>;
status = "disabled"; // disabled表示禁用该驱动
spi-max-frequency = <50000000>;
mode = <0>;
partition@0 {
reg = <0x0 0x1000000>;
label = "spi-flash";
};
};
...可以在npi-config里将其使能，如下:
$ npi-config 6 Advanced Options| Configure advanced setting A5 SPI| Enable/Disable SPI spi0 Enable/Disable spi0[enabled] spidev0.0| SPI0 char device spi-2.8'tft| Matrix-2'8_SPI_Key_TFT spi-flash| SPI0 flash(X)
设置完毕后，dtb里spi flash的status = "okay"，需要重启系统才能生效。
启动Linux系统时，看到类似下面的启动信息则说明SPI Flash被成功检测到了:
m25p80 spi0.0: mx25l12805d (16384 Kbytes) 1 ofpart partitions found on MTD device spi0.0 Creating 1 MTD partitions on "spi0.0": 0x000000000000-0x000001000000 : "spi-flash"
SPI Flash在Linux系统下的使用方法如下:
$ cat /sys/class/mtd/mtd0/size # 以byte为单位 $ cat /sys/class/block/mtdblock0/size # 以sector(512 byte)为单位 $ apt-get install mtd-utils $ flash_eraseall -j /dev/mtd0 # 格式成jffs2的格式 $ mount -t jffs2 /dev/mtdblock0 /mnt $ mkfs.ext4 /dev/mtdblock0 # 也格式化为ext4 $ mount -t ext4 /dev/mtdblock0 /mnt
3 H3/H2+
3.1 SPI Flash
FriendlyElec H3/H2+的Linux-4.14内核集成了"mxicy,mx25l12805d"的SPI Flash驱动，使用的是SPI0，但是默认并没有使能，相关的dts配置如下:
$ cat linux/arch/arm/boot/dts/sun8i-h3-nanopi.dtsi
&spi0 {
...
spiflash: spiflash@0 {
#address-cells = <1>;
#size-cells = <1>;
compatible = "mxicy,mx25l12805d";
reg = <0>;
status = "disabled"; // disabled表示禁用该驱动
spi-max-frequency = <50000000>;
mode = <0>;
partition@0 {
reg = <0x0 0x1000000>;
label = "spi-flash";
};
};
...开发人员可以自行修改和编译dts文件将其使能，也可以通过npi-config快速地将其使能，如下:
$ npi-config 6 Advanced Options| Configure advanced setting A5 SPI| Enable/Disable SPI spi0 Enable/Disable spi0[enabled] spidev0.0| SPI0 char device spi-2.8'tft| Matrix-2'8_SPI_Key_TFT spi-flash| SPI0 flash(X)
设置完毕后，dtb里spi flash的status = "okay"，需要重启系统才能生效。
启动Linux系统时，看到类似下面的启动信息则说明SPI Flash被成功检测到了:
m25p80 spi0.0: mx25l12805d (16384 Kbytes) 1 ofpart partitions found on MTD device spi0.0 Creating 1 MTD partitions on "spi0.0": 0x000000000000-0x000001000000 : "spi-flash"
SPI Flash在Linux系统下的使用方法如下:
$ cat /sys/class/mtd/mtd0/size # 以byte为单位 $ cat /sys/class/block/mtdblock0/size # 以sector(512 byte)为单位 $ apt-get install mtd-utils $ flash_eraseall -j /dev/mtd0 # 格式成jffs2的格式 $ mount -t jffs2 /dev/mtdblock0 /mnt $ mkfs.ext4 /dev/mtdblock0 # 也格式化为ext4 $ mount -t ext4 /dev/mtdblock0 /mnt
