Please tell me about device files.
The default device file is below.
mek_8q:/ $ cd dev
mek_8q:/dev $ ls -l
…
crw------- 1 root root 89, 1 2022-11-08 08:09 i2c-1
crw------- 1 root root 89, 2 2022-11-08 08:09 i2c-2
crw------- 1 root root 89, 3 2022-11-08 08:09 i2c-3
crw------- 1 root root 89, 4 2022-11-08 08:09 i2c-4
crw------- 1 root root 89, 5 2022-11-08 08:09 i2c-5
crw------- 1 root root 89, 6 2022-11-08 08:09 i2c-6
crw------- 1 root root 89, 7 2022-11-08 08:09 i2c-7
…
I edited the device tree and made i2c4 status="okay".
imx8qm-ss-dma.dtsi
&dma_subsys {
i2c4: i2c@5a840000 {
compatible = "fsl,imx8qm-lpi2c", "fsl,imx7ulp-lpi2c";
reg = <0x5a840000 0x4000>;
status = "okay";
};
imx8qm-mek.dts
&iomuxc {
pinctrl_i2c4: i2c4grp {
fsl,pins = <
IMX8QM_ENET1_MDC_DMA_I2C4_SCL 0x06000021
IMX8QM_ENET1_MDIO_DMA_I2C4_SDA 0x06000021
>;
};
Then the device file is:
mek_8q:/ $ cd dev
mek_8q:/dev $ ls -l
…
crw------- 1 root root 89, 1 2022-10-21 08:55 i2c-1
crw------- 1 root root 89, 2 2022-10-21 08:55 i2c-2
crw------- 1 root root 89, 3 2022-10-21 08:55 i2c-3
crw------- 1 root root 89, 4 2022-10-21 08:55 i2c-4
crw------- 1 root root 89, 5 2022-10-21 08:55 i2c-5
crw------- 1 root root 89, 6 2022-10-21 08:57 i2c-6
crw------- 1 root root 89, 7 2022-10-21 08:57 i2c-7
crw------- 1 root root 89, 8 2022-10-21 08:57 i2c-8
…
=> Which device is the added node (i2c4)? Is it i2c-8?
On the other hand, I also set i2c4=&i2c4 in the device tree aliases.
imx8qm.dtsi
/ {
aliases {
i2c0 = &i2c_rpbus_0;
i2c1 = &i2c_rpbus_1;
i2c4 = &i2c4;
};
Then the device file is:
mek_8q:/ $ cd dev
mek_8q:/dev $ ls -l
…
crw------- 1 root root 89, 1 2022-10-21 12:26 i2c-1
crw------- 1 root root 89, 4 2022-10-21 12:26 i2c-4
crw------- 1 root root 89, 5 2022-10-21 12:26 i2c-5
crw------- 1 root root 89, 6 2022-10-21 12:26 i2c-6
crw------- 1 root root 89, 7 2022-10-21 12:26 i2c-7
crw------- 1 root root 89, 8 2022-10-21 12:28 i2c-8
crw------- 1 root root 89, 9 2022-10-21 12:28 i2c-9
crw------- 1 root root 89, 10 2022-10-21 12:28 i2c-10
…
=> Which device is the added node (i2c4)? Is it i2c-4?
What are your other devices?
How are these numbered?
