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:
> > Am Freitag, 31. Januar 2025, 17:06:23 CET schrieb Frank Li:
> > > On Fri, Jan 31, 2025 at 02:54:06PM +0100, Alexander Stein wrote:
> > > > Hi,
> > > >
> > > > Am Donnerstag, 30. Januar 2025, 17:42:32 CET schrieb Frank Li:
> > > > > On Thu, Jan 30, 2025 at 02:01:00PM +0100, Alexander Stein wrote:
> > > > > > 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 <alexander.stein@xxxxxxxxxxxxxxx>
> > > > > > ---
> > > > > > drivers/nvmem/Kconfig | 3 ++
> > > > > > drivers/nvmem/imx-ocotp.c | 105 +++++++++++++++++++++++++++++++++++++-
> > > > > > 2 files changed, 107 insertions(+), 1 deletion(-)
> > > > > >
> ...
> > > > multiples fuses for disables. This is an excerpt from imx8mp WIP
> > > > > 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
> > > '#access-controller-cells = <2>'
> > and using the defines like this
> > > #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
>
> >
> > DT stays the same:
> > > access-controllers = <&ocotp IMX8MP_OCOTP_CAN_DISABLE>;
> >
> > Note: It seems BIT(x) is not usable in DT.
> >
> > Best regards,
> > Alexander
> > --
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> >
> >
