mbox series

[v3,0/3] tty: serial: samsung: Serial fixes for Apple A7-A11 SoCs

Message ID 20240908090939.2745-1-towinchenmi@gmail.com
Headers show
Series tty: serial: samsung: Serial fixes for Apple A7-A11 SoCs | expand

Message

Nick Chan Sept. 8, 2024, 9:05 a.m. UTC
Hi,

This series fixes issues with serial on A7-A11 SoCs. The changes do not
seem to affect existing M1 and up users so they can be applied
unconditionally.

Firstly, these SoCs require 32-bit writes on the serial port. This only
manifested in earlycon as reg-io-width in device tree is consulted for
normal serial writes.

Secondly, A7-A9 SoCs seems to use different bits for RXTO and RXTO
enable. Accessing these bits in addition to the original RXTO and RXTO
enable bits will allow serial rx to work correctly on those SoCs.

Changes in v3:
  - v2 did not declare itself as v2 in subject line... resend as v3.

Changes in v2:
  - Mention A7-A11 in the comment about changing register accesses to
    MMIO32.

  - Use BIT() macro for new entries, and change the existing APPLE_S5L_*
    entries for consistency.

v1: https://lore.kernel.org/linux-samsung-soc/20240907111431.2970-1-towinchenmi@gmail.com
v2: https://lore.kernel.org/linux-samsung-soc/20240908075904.12133-1-towinchenmi@gmail.com

Nick Chan

---

Nick Chan (3):
  tty: serial: samsung: Use BIT() macro for APPLE_S5L_*
  tty: serial: samsung: Fix A7-A11 serial earlycon SError
  tty: serial: samsung: Fix serial rx on Apple A7-A9

 drivers/tty/serial/samsung_tty.c | 22 ++++++++++++++++------
 include/linux/serial_s3c.h       | 24 ++++++++++++++----------
 2 files changed, 30 insertions(+), 16 deletions(-)


base-commit: 9aaeb87ce1e966169a57f53a02ba05b30880ffb8

Comments

Krzysztof Kozlowski Sept. 8, 2024, 9:14 a.m. UTC | #1
On 08/09/2024 11:05, Nick Chan wrote:
> Apple's older A7-A9 SoCs seems to use bit 3 in UTRSTAT as RXTO, which is
> enabled by bit 11 in UCON.
> 
> Access these bits in addition to the original RXTO and RXTO enable bits,
> to allow serial rx to function on A7-A9 SoCs. This change does not
> appear to affect the A10 SoC and up.
> 
> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>

This never happened. Please do not add fake tags.

Best regards,
Krzysztof
Nick Chan Sept. 8, 2024, 3:49 p.m. UTC | #2
On 8/9/2024 17:14, Krzysztof Kozlowski wrote:
> On 08/09/2024 11:05, Nick Chan wrote:
>> Apple's older A7-A9 SoCs seems to use bit 3 in UTRSTAT as RXTO, which is
>> enabled by bit 11 in UCON.
>>
>> Access these bits in addition to the original RXTO and RXTO enable bits,
>> to allow serial rx to function on A7-A9 SoCs. This change does not
>> appear to affect the A10 SoC and up.
>>
>> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
> 
> This never happened. Please do not add fake tags.
Sorry, this happened by mistake, and tags are added to both commits present
in previous versions by accident. I can send a v4 tomorrow, though I think
it is the best if this version is to be reviewed, since the mistake does
not make a difference in the patch submitted further upstream, and it saves
everyone's time.

> 
> Best regards,
> Krzysztof
> 

Nick Chan