diff mbox series

[v1,2/3] dt-bindings: serial: samsung: add Exynos990 compatible

Message ID 20250212234034.284-3-wachiturroxd150@gmail.com (mailing list archive)
State New
Headers show
Series arm64: dts: exynos990: define all PERIC0/1 USI nodes | expand

Commit Message

Denzeel Oliva Feb. 12, 2025, 11:40 p.m. UTC
Add samsung,exynos990-uart compatible. It falls back to
samsung,exynos8895-uart since FIFO size is defined in DT.

Signed-off-by: Denzeel Oliva <wachiturroxd150@gmail.com>
---
 Documentation/devicetree/bindings/serial/samsung_uart.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Tudor Ambarus Feb. 13, 2025, 7:20 a.m. UTC | #1
On 2/12/25 11:40 PM, Denzeel Oliva wrote:
> Add samsung,exynos990-uart compatible. It falls back to
> samsung,exynos8895-uart since FIFO size is defined in DT.

doesn't the 32 bit register restriction apply to uart as it applies to
SPI? If so, you shall probably fallback to gs101.
Denzeel Oliva Feb. 14, 2025, 5:16 a.m. UTC | #2
On Thu, Feb 13, 2025 at 07:20:22AM +0000, Tudor Ambarus wrote:
> doesn't the 32 bit register restriction apply to uart as it applies to
> SPI? If so, you shall probably fallback to gs101.

Of course not, downstream of the UART serial driver there is nothing
specified about 32-bit access restriction, nothing explicitly
in the driver. [0]

https://github.com/pascua28/android_kernel_samsung_s20fe/blob/3be539e9cd22b89ba3cc8282945a0c46ff27341d/drivers/tty/serial/samsung.c#L1543
Tudor Ambarus Feb. 14, 2025, 6:42 a.m. UTC | #3
On 2/14/25 5:16 AM, Denzeel Oliva wrote:
> On Thu, Feb 13, 2025 at 07:20:22AM +0000, Tudor Ambarus wrote:
>> doesn't the 32 bit register restriction apply to uart as it applies to
>> SPI? If so, you shall probably fallback to gs101.
> 
> Of course not, downstream of the UART serial driver there is nothing
> specified about 32-bit access restriction, nothing explicitly
> in the driver. [0]
> 
> https://github.com/pascua28/android_kernel_samsung_s20fe/blob/3be539e9cd22b89ba3cc8282945a0c46ff27341d/drivers/tty/serial/samsung.c#L1543

that's very strange. uart and spi are part of the same USI IP, on the
same bus. I don't think you can have the same IP requiring 32 bit
accesses for SPI but allow 8-bit accesses for uart.

Maybe SPI can work with 8bit accesses? How did you test SPI and uart?
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/serial/samsung_uart.yaml b/Documentation/devicetree/bindings/serial/samsung_uart.yaml
index 070eba9f1..f38be8e95 100644
--- a/Documentation/devicetree/bindings/serial/samsung_uart.yaml
+++ b/Documentation/devicetree/bindings/serial/samsung_uart.yaml
@@ -28,6 +28,7 @@  properties:
           - samsung,exynos5433-uart
           - samsung,exynos850-uart
           - samsung,exynos8895-uart
+          - samsung,exynos990-uart
       - items:
           - enum:
               - samsung,exynos7-uart
@@ -42,6 +43,10 @@  properties:
               - samsung,exynosautov9-uart
               - samsung,exynosautov920-uart
           - const: samsung,exynos850-uart
+      - items:
+          - enum:
+              - samsung,exynos990-uart
+          - const: samsung,exynos8895-uart
 
   reg:
     maxItems: 1
@@ -162,6 +167,7 @@  allOf:
             enum:
               - google,gs101-uart
               - samsung,exynos8895-uart
+              - samsung,exynos990-uart
     then:
       required:
         - samsung,uart-fifosize