RE: [PATCH v6 4/4] clk: samsung: add top clock support for ExynosAuto v920 SoC

Hello Krzysztof,

-----Original Message-----
From: Krzysztof Kozlowski <krzk@kernel.org>
Sent: Wednesday, August 21, 2024 3:23 PM
To: sunyeal.hong <redacted>; 'Kwanghoon Son'
[off-list ref]; 'Sylwester Nawrocki' [off-list ref];
'Chanwoo Choi' [off-list ref]; 'Alim Akhtar'
[off-list ref]; 'Michael Turquette' [off-list ref];
'Stephen Boyd' [off-list ref]; 'Rob Herring' [off-list ref]; 'Conor
Dooley' [off-list ref]
Cc: linux-samsung-soc@vger.kernel.org; linux-clk@vger.kernel.org;
devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org; linux-
kernel@vger.kernel.org
Subject: Re: [PATCH v6 4/4] clk: samsung: add top clock support for
ExynosAuto v920 SoC

On 21/08/2024 04:23, sunyeal.hong wrote:

quoted

Hello Kwanghoon,

quoted

-----Original Message-----
From: Kwanghoon Son <redacted>
Sent: Tuesday, August 20, 2024 6:54 PM
To: sunyeal.hong <redacted>; 'Krzysztof Kozlowski'
[off-list ref]; 'Sylwester Nawrocki' [off-list ref];
'Chanwoo Choi' [off-list ref]; 'Alim Akhtar'
[off-list ref]; 'Michael Turquette'

[off-list ref]; 'Stephen Boyd'

quoted

quoted

[off-list ref]; 'Rob Herring' [off-list ref]; 'Conor Dooley'
[off-list ref]
Cc: linux-samsung-soc@vger.kernel.org; linux-clk@vger.kernel.org;
devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
linux- kernel@vger.kernel.org
Subject: Re: [PATCH v6 4/4] clk: samsung: add top clock support for
ExynosAuto v920 SoC

On Tue, 2024-08-20 at 10:50 +0900, sunyeal.hong wrote:

quoted

Hello Kwanghoon,

quoted

-----Original Message-----
From: Kwanghoon Son <redacted>
Sent: Monday, August 19, 2024 6:32 PM
To: Sunyeal Hong <redacted>; Krzysztof Kozlowski
[off-list ref]; Sylwester Nawrocki [off-list ref];
Chanwoo Choi [off-list ref]; Alim Akhtar
[off-list ref]; Michael Turquette
[off-list ref]; Stephen Boyd [off-list ref]; Rob
Herring [off-list ref]; Conor Dooley [off-list ref]
Cc: linux-samsung-soc@vger.kernel.org; linux-clk@vger.kernel.org;
devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
linux- kernel@vger.kernel.org
Subject: Re: [PATCH v6 4/4] clk: samsung: add top clock support for
ExynosAuto v920 SoC

On Mon, 2024-08-19 at 14:24 +0900, Sunyeal Hong wrote:

quoted

This adds support for CMU_TOP which generates clocks for all the
function blocks such as CORE, HSI0/1/2, PERIC0/1 and so on. For
CMU_TOP, PLL_SHARED0,1,2,3,4 and 5 will be the sources of this
block and they will generate bus clocks.

Signed-off-by: Sunyeal Hong <redacted>
---
 drivers/clk/samsung/Makefile             |    1 +
 drivers/clk/samsung/clk-exynosautov920.c | 1173
++++++++++++++++++++++
 2 files changed, 1174 insertions(+)  create mode 100644
drivers/clk/samsung/clk-exynosautov920.c

diff --git a/drivers/clk/samsung/Makefile

b/drivers/clk/samsung/Makefile index 3056944a5a54..f1ba48758c78
100644

--- a/drivers/clk/samsung/Makefile
+++ b/drivers/clk/samsung/Makefile

@@ -21,6 +21,7 @@ obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-

exynos7.o

quoted

 obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-exynos7885.o
 obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-exynos850.o
 obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-exynosautov9.o
+obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-exynosautov920.o
 obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-gs101.o
 obj-$(CONFIG_S3C64XX_COMMON_CLK)	+= clk-s3c64xx.o
 obj-$(CONFIG_S5PV210_COMMON_CLK)	+= clk-s5pv210.o clk-s5pv210-

audss.o

quoted

diff --git a/drivers/clk/samsung/clk-exynosautov920.c

b/drivers/clk/samsung/clk-exynosautov920.c
new file mode 100644
index 000000000000..c17d25e3c9a0

--- /dev/null
+++ b/drivers/clk/samsung/clk-exynosautov920.c

[snip]

quoted

+};
+
+static const struct samsung_cmu_info peric0_cmu_info __initconst
+=

{

quoted

quoted

quoted

+	.mux_clks		= peric0_mux_clks,
+	.nr_mux_clks		= ARRAY_SIZE(peric0_mux_clks),
+	.div_clks		= peric0_div_clks,
+	.nr_div_clks		= ARRAY_SIZE(peric0_div_clks),
+	.nr_clk_ids		= CLKS_NR_PERIC0,
+	.clk_regs		= peric0_clk_regs,
+	.nr_clk_regs		= ARRAY_SIZE(peric0_clk_regs),
+	.clk_name		= "dout_clkcmu_peric0_noc",

same question.
Isn't it "noc"?
https://lore.kernel.org/linux-samsung-
soc/58dfae564a4a624e464c7803a309f1f07b5ae83d.camel@samsung.com/

In my case(autov9), if put wrong clk_name dmesg will show that,
exynos_arm64_register_cmu: could not enable bus clock ...; err = -2

Kwang.

clk_name follows the guide document provided by hw. v9 is bus, but
v920

uses noc.

What I mean,

.clk_name		= "dout_clkcmu_peric0_noc", // wrong
.clk_name		= "noc", // correct

Because there is no clock-names "dout_clkcmu_peric0_noc" in
exynos/exynosautov920.dtsi.

The clk_name written here has nothing to do with the device tree. Please

look at the code carefully.

Hm? I see in the code clearly:

	clk_get(dev, cmu->clk_name);

Where cmu is the discussed struct.

If you claim it does not have anything to do with DT, then what is it for?

Best regards,
Krzysztof

In general, clk_get is used via the clk_name declared in the DT.

However, the question asked here is the parent clock name of peric0_noc, so it is unrelated to the device tree.

	PNAME(mout_peric0_noc_user_p) = { "oscclk", "dout_clkcmu_peric0_noc" };

So we are using clk_name as "dout_clkcmu_peric0_noc".

Best Regards,
sunyeal