Hi Sam,
On Thu, Oct 14, 2021 at 04:35:06PM +0300, Sam Protsenko wrote:
> Old Exynos SoCs have both Product ID and Revision ID in one single
> register, while new SoCs tend to have two separate registers for those
> IDs. Implement handling of both cases by passing Revision ID register
> offsets in driver data.
>
> Previously existing macros for Exynos4210 (removed in this patch) were
> incorrect:
>
> #define EXYNOS_SUBREV_MASK (0xf << 4)
> #define EXYNOS_MAINREV_MASK (0xf << 0)
>
> Actual format of PRO_ID register in Exynos4210 (offset 0x0):
>
> [31:12] Product ID
> [9:8] Package information
> [7:4] Main Revision Number
> [3:0] Sub Revision Number
>
> This patch doesn't change the behavior on existing platforms, so
> '/sys/devices/soc0/revision' will show the same string as before.
>
> Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
> ---
> Changes in v2:
> - Renamed *_rev_bit fields in 'struct exynos_chipid_variant' to
> *_rev_shift
> - Renamed EXYNOS_REV_PART_LEN to EXYNOS_REV_PART_MASK
> - Renamed EXYNOS_REV_PART_OFF to EXYNOS_REV_PART_SHIFT
>
> Changes in v3:
> - Rebased on top of krzk/for-next tree
> - Fixed wrong *_rev_shift values in exynos4210_chipid_drv_data
> - Implemented reading the register only once in case when both
> Product ID and Revision ID are stored in the same register
> - Tested all possible cases by emulating read register values
> - Provided more detailed explanation in commit message
>
> drivers/soc/samsung/exynos-chipid.c | 69 +++++++++++++++++++----
> include/linux/soc/samsung/exynos-chipid.h | 6 +-
> 2 files changed, 60 insertions(+), 15 deletions(-)
>
I tested this on exynos4412-i9300 and an exynos5420 tablet that is not
yet in mainline. /sys/devices/soc0/* looks identical, I have:
$ cat /sys/devices/soc0/{family,revision,soc_id}
Samsung Exynos
11
EXYNOS4412
and
$ cat /sys/devices/soc0/{family,revision,soc_id}
Samsung Exynos
20
EXYNOS5420
before and after these patches. The printed PRO_ID in dmesg changed
though, before I had:
[ 0.894683] soc soc0: Exynos: CPU[EXYNOS4412] PRO_ID[0xe4412211] REV[0x11] Detected
[ 4.964215] soc soc0: Exynos: CPU[EXYNOS5420] PRO_ID[0xe5420020] REV[0x20] Detected
But after it looks like package information and revision is missing
from the reported PRO_ID:
[ 0.885515] soc soc0: Exynos: CPU[EXYNOS4412] PRO_ID[0xe4412000] REV[0x11] Detected
[ 4.965560] soc soc0: Exynos: CPU[EXYNOS5420] PRO_ID[0xe5420000] REV[0x20] Detected
Best regards,
Henrik Grimler
