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References: <20210914155607.14122-1-semen.protsenko@linaro.org>
 <20210914155607.14122-5-semen.protsenko@linaro.org> <96e5587e-aca7-248e-6448-8edfc70784b7@gmail.com>
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From:   Sam Protsenko <semen.protsenko@linaro.org>
Date:   Tue, 5 Oct 2021 13:28:40 +0300
Message-ID: <CAPLW+4mEeh8Fo8kGHx+rB7nX7bDfaQRPGDotgPLTp4pm4rC0Cg@mail.gmail.com>
Subject: Re: [PATCH 4/6] dt-bindings: clock: Add bindings definitions for
 Exynos850 CMU
To:     Chanwoo Choi <cwchoi00@gmail.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc:     =?UTF-8?Q?Pawe=C5=82_Chmiel?= <pawel.mikolaj.chmiel@gmail.com>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Tomasz Figa <tomasz.figa@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Ryu Euiyoul <ryu.real@samsung.com>,
        Tom Gall <tom.gall@linaro.org>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        John Stultz <john.stultz@linaro.org>,
        Amit Pundir <amit.pundir@linaro.org>,
        devicetree <devicetree@vger.kernel.org>,
        linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
        linux-clk <linux-clk@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Samsung SOC <linux-samsung-soc@vger.kernel.org>
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On Wed, 15 Sept 2021 at 19:37, Chanwoo Choi <cwchoi00@gmail.com> wrote:
>
> Hi,
>
> You don't add clock ids for the all defined clocks in clk-exynos850.c.
> I recommend that add all clock ids for the defined clocks if possible.
>
> If you want to change the parent clock of mux or change the clock rate
> of div rate for some clocks, you have to touch the files as following:
> - include/dt-bindings/clock/exynos850.h
> - drivers/clk/samsung/clk-exynos850.c
> - exynos850 dt files
>
> If you define the clock ids for all clocks added to this patchset,
> you can change the parent or rate by just editing the dt files.
>

Hi Chanwoo,

I see your point. But I have intentionally omitted some clock ids,
which can't be / shouldn't be used by consumers in device tree.
Actually I took that idea from clk-exynos7.c.

Krzysztof, Sylwester: can you please advice if all clock ids should be
defined, or only those that are going to be used in dts clk consumers?
I don't mind reworking the patch, just want to be sure which design
approach we want to follow.

Thanks!

> But, I have no strongly objection about just keeping this patch.
>
>
> On 21. 9. 15. =EC=98=A4=EC=A0=84 12:56, Sam Protsenko wrote:
> > Clock controller driver is designed to have separate instances for each
> > particular CMU. So clock IDs in this bindings header also start from 1
> > for each CMU.
> >
> > Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
> > ---
> >   include/dt-bindings/clock/exynos850.h | 72 ++++++++++++++++++++++++++=
+
> >   1 file changed, 72 insertions(+)
> >   create mode 100644 include/dt-bindings/clock/exynos850.h
> >
> > diff --git a/include/dt-bindings/clock/exynos850.h b/include/dt-binding=
s/clock/exynos850.h
> > new file mode 100644
> > index 000000000000..2f0a7f619627
> > --- /dev/null
> > +++ b/include/dt-bindings/clock/exynos850.h
> > @@ -0,0 +1,72 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Linaro Ltd.
> > + * Author: Sam Protsenko <semen.protsenko@linaro.org>
> > + *
> > + * Device Tree binding constants for Exynos850 clock controller.
> > + */
> > +
> > +#ifndef _DT_BINDINGS_CLOCK_EXYNOS_850_H
> > +#define _DT_BINDINGS_CLOCK_EXYNOS_850_H
> > +
> > +/* CMU_TOP */
> > +#define DOUT_HSI_BUS                 1
> > +#define DOUT_HSI_MMC_CARD            2
> > +#define DOUT_HSI_USB20DRD            3
> > +#define DOUT_PERI_BUS                        4
> > +#define DOUT_PERI_UART                       5
> > +#define DOUT_PERI_IP                 6
> > +#define DOUT_CORE_BUS                        7
> > +#define DOUT_CORE_CCI                        8
> > +#define DOUT_CORE_MMC_EMBD           9
> > +#define DOUT_CORE_SSS                        10
> > +#define TOP_NR_CLK                   11
> > +
> > +/* CMU_HSI */
> > +#define GOUT_USB_RTC_CLK             1
> > +#define GOUT_USB_REF_CLK             2
> > +#define GOUT_USB_PHY_REF_CLK         3
> > +#define GOUT_USB_PHY_ACLK            4
> > +#define GOUT_USB_BUS_EARLY_CLK               5
> > +#define GOUT_GPIO_HSI_PCLK           6
> > +#define GOUT_MMC_CARD_ACLK           7
> > +#define GOUT_MMC_CARD_SDCLKIN                8
> > +#define GOUT_SYSREG_HSI_PCLK         9
> > +#define HSI_NR_CLK                   10
> > +
> > +/* CMU_PERI */
> > +#define GOUT_GPIO_PERI_PCLK          1
> > +#define GOUT_HSI2C0_IPCLK            2
> > +#define GOUT_HSI2C0_PCLK             3
> > +#define GOUT_HSI2C1_IPCLK            4
> > +#define GOUT_HSI2C1_PCLK             5
> > +#define GOUT_HSI2C2_IPCLK            6
> > +#define GOUT_HSI2C2_PCLK             7
> > +#define GOUT_I2C0_PCLK                       8
> > +#define GOUT_I2C1_PCLK                       9
> > +#define GOUT_I2C2_PCLK                       10
> > +#define GOUT_I2C3_PCLK                       11
> > +#define GOUT_I2C4_PCLK                       12
> > +#define GOUT_I2C5_PCLK                       13
> > +#define GOUT_I2C6_PCLK                       14
> > +#define GOUT_MCT_PCLK                        15
> > +#define GOUT_PWM_MOTOR_PCLK          16
> > +#define GOUT_SPI0_IPCLK                      17
> > +#define GOUT_SPI0_PCLK                       18
> > +#define GOUT_SYSREG_PERI_PCLK                19
> > +#define GOUT_UART_IPCLK                      20
> > +#define GOUT_UART_PCLK                       21
> > +#define GOUT_WDT0_PCLK                       22
> > +#define GOUT_WDT1_PCLK                       23
> > +#define PERI_NR_CLK                  24
> > +
> > +/* CMU_CORE */
> > +#define GOUT_CCI_ACLK                        1
> > +#define GOUT_GIC_CLK                 2
> > +#define GOUT_MMC_EMBD_ACLK           3
> > +#define GOUT_MMC_EMBD_SDCLKIN                4
> > +#define GOUT_SSS_ACLK                        5
> > +#define GOUT_SSS_PCLK                        6
> > +#define CORE_NR_CLK                  7
> > +
> > +#endif /* _DT_BINDINGS_CLOCK_EXYNOS_850_H */
> >
>
>
> --
> Best Regards,
> Samsung Electronics
> Chanwoo Choi