Re: 回复: 回复: 回复: [PATCH v4 04/20] firmware: scmi: add pin control protocol support to SCMI agent

[Marek Vasut]

On 3/3/25 9:04 AM, Alice Guo (OSS) wrote:

[...]

>>> In Linux Kernel, there are two drivers, pinctrl-scmi.c and pinctrl-imx-scmi.c.
>>> Both follows ARM SCMI 3.2, but pinctrl-imx-scmi has some special
>>> settings to align with i.mx iomuxc array based settings, mux,input,pad and etc.
>>>
>>> In gerneral, imx part could be merged with pinctrl-scmi.c but that
>>> will make code not clean.
>> In that case, why does U-Boot not have pinctrl-imx-scmi.c to contain the iMX
>> customization too ? If this protocol is IMX specific, it shouldn't be ifdeffed in
>> common code.
> 
> Is it acceptable to rename " drivers/pinctrl/nxp/pinctrl-scmi.c" to "drivers/pinctrl/nxp/ pinctrl-imx-scmi.c"? SCMI_PROTOCOL_ID_PINCTRL = 0x19 is not i.MX specific.

Look at this commit, which allows drivers placed in some driver.c file 
insert their driver entry into a linker list, and then some common code 
can iterate over this linker list and match drivers against some properties.

In this case, it is a PHY driver which does list supported PHY IDs in 
each U_BOOT_PHY_DRIVER, and the common code checks whether the PHY IDs 
match when a new PHY gets registered:

7940a93eb977 ("net: phy: Iterate over both registered PHYs and struct 
phy_driver linker list")

This is the driver side conversion example:

20bd8e4fcbb5 ("net: phy: gen10g: Convert to U_BOOT_PHY_DRIVER()")

What you could do is the same:

- Basically duplicate the mechanism in 7940a93eb977 ("net: phy: Iterate 
over both registered PHYs and struct phy_driver linker list"), call it 
e.g. U_BOOT_SCMI_DRIVER()
- Switch SCMI drivers to use U_BOOT_SCMI_DRIVER , have each one list a 
protocol ID (instead of the PHY IDs), and then use the 
scmi_agent-uclass.c to iterate over all the linker lists

About the MX95 specifics and handling those, it is possible to have two 
drivers which support the same hardware compiled into U-Boot and have 
them decide at bind time which driver should bind and which not, look at 
drivers/mtd/renesas_rpc_hf.c rpc_hf_probe() and 
drivers/spi/renesas_rpc_spi.c rpc_spi_bind() for example of doing this.

I hope this helps untangle the SCMI implementation.