Re: [PATCH v1 1/2] dt-bindings: i2c: exynos5: Add samsung,exynos8895-hsi2c compatible

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Hi Krzysztof,

On 12/17/24 11:43 AM, Krzysztof Kozlowski wrote:
On 17/12/2024 10:31, Ivaylo Ivanov wrote:
On 12/17/24 11:26, Krzysztof Kozlowski wrote:
On 17/12/2024 10:08, Ivaylo Ivanov wrote:
        - items:
            - enum:
@@ -94,9 +95,28 @@ allOf:
          - clock-names
else:
-      properties:
-        clocks:
-          maxItems: 1
+      if:
+        properties:
+          compatible:
+            contains:
+              enum:
+                - samsung,exynos8895-hsi2c
+
+      then:
+        properties:
+          clocks:
Missing minItems

+            maxItems: 2
+
+          clock-names:
Ditto

+            maxItems: 2
+
+        required:
+          - clock-names
I don't understand why do you need second, same branch in if, basically
Because, as I stated in the commit message, we have HSI2C controllers
both implemented in USIv1 blocks and outside. These that are a part of
On Exynos8895? Where? With the same compatible?
hsi2c_0 which has a clock from BUSC and hsi2c_1 to hsi2c_4 which use clocks
from PERIC1 (CLK_GOUT_PERIC1_HSI2C_CAM{0,1,2,3}_IPCLK). Why would
they need a different compatible though? It's functionally the same i2c design
as the one implemented in USIv1 blocks.
If one block is part of USI and other not, they might not be the same
I2C blocks, even if interface is similar. If they were the same or even
functionally the same, they would have the same clock inputs. However
I see, so in such case I should make samsung,exynos8895-hsi2c-nonusi or
something like that?

user manual also suggests that there is only one clock, not two (for
both cases), so they could be functionally equivalent but then number of
clocks looks incorrect.
That'd be weird. Both according to downstream and upstream clk driver,
for the USI-implemented i2cs we have a pclk and an sclk_usi.
Something is not precise here, as usually with Samsung clock topology.

First, the non-USI instances have the IPCLK as well, e.g. things like
PERIC1_UID_HSI2C_CAM1_IPCLKPORT_iPCLK

USI have BLK_PERIC0_UID_USI03_IPCLKPORT_i_SCLK_USI, but that's USI
clock, not HSI2C in USI. Datasheet mentions this is UART and SPI special
clock, but not I2C. The PCLK is used for HSI2C iPCLK.

In USI, USI PCLK is used for the internal AMBA APB bus clock and the IPCLK signal is used for the peripheral controller blocks (i2c/spi/uart).

So perhaps we have it described incorrectly, and the hsi2c controllers (at least on E8895) should take only one clock input (IPCLK), and USI block should take the PCLK input.




Best regards,
Krzysztof


- Markuss





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