On Wed, Feb 05, 2025 at 11:43:22AM -0500, Frank Li wrote:

On Wed, Feb 05, 2025 at 07:51:23AM +0100, Alexander Stein wrote:

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Am Freitag, 31. Januar 2025, 17:06:23 CET schrieb Frank Li:

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On Fri, Jan 31, 2025 at 02:54:06PM +0100, Alexander Stein wrote:

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Hi,

Am Donnerstag, 30. Januar 2025, 17:42:32 CET schrieb Frank Li:

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On Thu, Jan 30, 2025 at 02:01:00PM +0100, Alexander Stein wrote:

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i.MX8M OCOTP supports a specific peripheral or function being fused
which means disabled, so
 - Introduce disable_fuse for a list of possible fused peripherals.
 - Iterate all nodes to check accessing permission. If not
   allowed to be accessed, detach the node

Signed-off-by: Alexander Stein <redacted>
---
 drivers/nvmem/Kconfig     |   3 ++
 drivers/nvmem/imx-ocotp.c | 105 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 107 insertions(+), 1 deletion(-)

...

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multiples fuses for disables. This is an excerpt from imx8mp WIP

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struct disable_fuse imx8mp_disable_fuse[] = {
	[IMX8MP_OCOTP_CAN_DISABLE]		= { .fuse_addr = 16, .mask = BIT(28) },
	[IMX8MP_OCOTP_CAN_FD_DISABLE]		= { .fuse_addr = 16, .mask = BIT(29) },
	[IMX8MP_OCOTP_VPU_VC8000E_DISABLE]	= { .fuse_addr = 16, .mask = BIT(30) },
	[IMX8MP_OCOTP_IMG_ISP1_DISABLE]		= { .fuse_addr = 20, .mask = BIT(0) },
	[IMX8MP_OCOTP_IMG_ISP2_DISABLE]		= { .fuse_addr = 20, .mask = BIT(1) },
	[IMX8MP_OCOTP_IMG_DEWARP_DISABLE]	= { .fuse_addr = 20, .mask = BIT(2) },
};

Notice the fuse_addr of 16 and 20.

Yes, I am not sure if it good idea to encode fuse_addr to IMX8MP_OCOTP_CAN_DISABLE

like

#define IMX8MP_OCOTP_CAN_DISABLE  16 << 16 | BIT(28)

So dt-bindings/nvmem/fsl,imx8mn-ocotp.h can be moved to dts directory.

Mh, I personally don't like encoding offsets into bits. How about using

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'#access-controller-cells = <2>'

and using the defines like this

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#define IMX8MP_OCOTP_CAN_DISABLE  16 0x10000000

I think it is good. better told peng fan to align this!

It'd better use bit offset directly. such as

#define IMX8MP_OCOTP_CAN_DISABLE  16 28

So binding doc easy to limit it to 0..31.

Frank

Frank

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DT stays the same:

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access-controllers = <&ocotp IMX8MP_OCOTP_CAN_DISABLE>;

Note: It seems BIT(x) is not usable in DT.

Best regards,
Alexander
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