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[v1,0/2] spi: s3c64xx: add support for samsung,exynos990-spi

Message ID 20250212191241.280-1-wachiturroxd150@gmail.com
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Series spi: s3c64xx: add support for samsung,exynos990-spi | expand

Message

Denzeel Oliva Feb. 12, 2025, 7:12 p.m. UTC 
The Exynos990 SPI controller shares similarities with
the GS101 (Google Tensor) SPI implementation,
but introduces specific hardware requirements such as
32-bit register access and variable FIFO depths depending on
the SPI node where it will have to be specified in DT (Device Tree).

Denzeel Oliva (2):
  spi: dt-bindings: samsung: add samsung,exynos990-spi compatible
  spi: s3c64xx: add support exynos990-spi to new port config data

 .../devicetree/bindings/spi/samsung,spi.yaml    |  1 +
 drivers/spi/spi-s3c64xx.c                       | 17 +++++++++++++++++
 2 files changed, 18 insertions(+)

Comments

Denzeel Oliva Feb. 13, 2025, 7:47 p.m. UTC | #1 
On Thu, Feb 13, 2025 at 07:05:22AM +0000, Tudor Ambarus wrote:
> gs101 mandates 32-bit accesses too.

Also in exynos990 [0]

> > the SPI node where it will have to be specified in DT (Device Tree).
> 
> gs101 has some USI nodes that can work only in uart mode and indeed the
> fifosize there is 256. Does downstream define SPI nodes with 256 bytes
> FIFOs? Can you please point me the the downstream code?
> 

Yes, Exynos990 has SPI nodes with 256-byte FIFOs, and you can see this in
the downstream kernel. Here are some relevant references:

- SPI8: [1]
- SPI9: [2]
- SPI10: [3]

Best regards,
Denzeel

[0] https://github.com/pascua28/android_kernel_samsung_s20fe/blob/3be539e9cd22b89ba3cc8282945a0c46ff27341d/drivers/spi/spi-s3c64xx.c#L767
[1] https://github.com/pascua28/android_kernel_samsung_s20fe/blob/3be539e9cd22b89ba3cc8282945a0c46ff27341d/arch/arm64/boot/dts/exynos/exynos9830-usi.dtsi#L1641
[2] https://github.com/pascua28/android_kernel_samsung_s20fe/blob/3be539e9cd22b89ba3cc8282945a0c46ff27341d/arch/arm64/boot/dts/exynos/exynos9830-usi.dtsi#L1662
[3] https://github.com/pascua28/android_kernel_samsung_s20fe/blob/3be539e9cd22b89ba3cc8282945a0c46ff27341d/arch/arm64/boot/dts/exynos/exynos9830-usi.dtsi#L1683
Tudor Ambarus Feb. 14, 2025, 6:14 a.m. UTC | #2 
On 2/13/25 7:47 PM, Denzeel Oliva wrote:
> Yes, Exynos990 has SPI nodes with 256-byte FIFOs, and you can see this in
> the downstream kernel. Here are some relevant references:

thanks for the references!