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Date:   Fri, 9 Jun 2023 15:57:19 +0300
From:   Dmitry Rokosov <ddrokosov@sberdevices.ru>
To:     Neil Armstrong <neil.armstrong@linaro.org>
CC:     Jerome Brunet <jbrunet@baylibre.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Kevin Hilman <khilman@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        <linux-amlogic@lists.infradead.org>, <linux-clk@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>
Subject: Re: [PATCH 03/18] clk: meson: migrate a1 clock drivers out of
 hw_onecell_data to drop NR_CLKS
Message-ID: <20230609125719.ji2vvcvwslrzu2oc@CAB-WSD-L081021>
References: <20230607-topic-amlogic-upstream-clkid-public-migration-v1-0-9676afa6b22c@linaro.org>
 <20230607-topic-amlogic-upstream-clkid-public-migration-v1-3-9676afa6b22c@linaro.org>
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 <638206ba-e2da-bb8e-a2e4-138af84648b4@linaro.org>
 <20230609114847.x24by2foebojbchq@CAB-WSD-L081021>
 <04791890-56f3-e620-1660-e8ed80eb5752@linaro.org>
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On Fri, Jun 09, 2023 at 02:47:04PM +0200, Neil Armstrong wrote:
> Hi,
> 
> On 09/06/2023 13:48, Dmitry Rokosov wrote:
> > Hello Neil,
> > 
> > On Thu, Jun 08, 2023 at 02:53:50PM +0200, Neil Armstrong wrote:
> > > On 08/06/2023 14:45, Jerome Brunet wrote:
> > > > > +struct meson_a1_pll_clks {
> > > > > +	struct clk_hw **hw_clks;
> > > > > +	unsigned int hw_clk_num;
> > > > > +};
> > > > > +
> > > > > +static struct meson_a1_pll_clks a1_pll_clks = {
> > > > > +	.hw_clks = a1_pll_hw_clks,
> > > > > +	.hw_clk_num = ARRAY_SIZE(a1_pll_hw_clks),
> > > > > +};
> > > > > +
> > > > > +static struct clk_hw *meson_a1_pll_hw_get(struct of_phandle_args *clkspec, void *clk_data)
> > > > > +{
> > > > > +	const struct meson_a1_pll_clks *data = clk_data;
> > > > > +	unsigned int idx = clkspec->args[0];
> > > > > +
> > > > > +	if (idx >= data->hw_clk_num) {
> > > > > +		pr_err("%s: invalid index %u\n", __func__, idx);
> > > > > +		return ERR_PTR(-EINVAL);
> > > > > +	}
> > > > > +
> > > > > +	return data->hw_clks[idx];
> > > > > +}
> > > > 
> > > > I'd prefer to have a single struct type and and single custom
> > > > callback for the different SoC please.
> > > 
> > > Sure, I've written a common code for that, but I have a hard time finding
> > > a proper naming for it... so I choosed meson-clkc since it could have
> > > more common helper code for duplicated code over the clk driver:
> > > 
> > > ===================================><============================================================================
> > > diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
> > > index 8ce846fdbe43..9070dcfd9e71 100644
> > > --- a/drivers/clk/meson/Kconfig
> > > +++ b/drivers/clk/meson/Kconfig
> > > @@ -30,6 +30,9 @@ config COMMON_CLK_MESON_VID_PLL_DIV
> > >   	tristate
> > >   	select COMMON_CLK_MESON_REGMAP
> > > 
> > > +config COMMON_CLK_MESON_CLKC
> > > +	tristate
> > > +
> > >   config COMMON_CLK_MESON_AO_CLKC
> > >   	tristate
> > >   	select COMMON_CLK_MESON_REGMAP
> > > diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
> > > index d5288662881d..13c6db466986 100644
> > > --- a/drivers/clk/meson/Makefile
> > > +++ b/drivers/clk/meson/Makefile
> > > @@ -1,6 +1,7 @@
> > >   # SPDX-License-Identifier: GPL-2.0-only
> > >   # Amlogic clock drivers
> > > 
> > > +obj-$(CONFIG_COMMON_CLK_MESON_CLKC) += meson-clkc.o
> > >   obj-$(CONFIG_COMMON_CLK_MESON_AO_CLKC) += meson-aoclk.o
> > >   obj-$(CONFIG_COMMON_CLK_MESON_CPU_DYNDIV) += clk-cpu-dyndiv.o
> > >   obj-$(CONFIG_COMMON_CLK_MESON_DUALDIV) += clk-dualdiv.o
> > > diff --git a/drivers/clk/meson/meson-clkc.c b/drivers/clk/meson/meson-clkc.c
> > > new file mode 100644
> > > index 000000000000..fa98b9d09011
> > > --- /dev/null
> > > +++ b/drivers/clk/meson/meson-clkc.c
> > > @@ -0,0 +1,25 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +/*
> > > + * Copyright (c) 2023 Neil Armstrong <neil.armstrong@linaro.org>
> > > + */
> > > +
> > > +#include <linux/of_device.h>
> > > +#include <linux/clk-provider.h>
> > > +#include <linux/module.h>
> > > +#include "meson-clkc.h"
> > > +
> > > +struct clk_hw *meson_clk_hw_get(struct of_phandle_args *clkspec, void *clk_hw_data)
> > > +{
> > > +	const struct meson_clk_hw_data *data = clk_hw_data;
> > > +	unsigned int idx = clkspec->args[0];
> > > +
> > > +	if (idx >= data->num) {
> > > +		pr_err("%s: invalid index %u\n", __func__, idx);
> > > +		return ERR_PTR(-EINVAL);
> > > +	}
> > > +
> > > +	return data->hws[idx];
> > > +}
> > > +EXPORT_SYMBOL_GPL(meson_clk_hw_get);
> > > +
> > > +MODULE_LICENSE("GPL v2");
> > > diff --git a/drivers/clk/meson/meson-clkc.h b/drivers/clk/meson/meson-clkc.h
> > > new file mode 100644
> > > index 000000000000..e3bad2aa17eb
> > > --- /dev/null
> > > +++ b/drivers/clk/meson/meson-clkc.h
> > > @@ -0,0 +1,19 @@
> > > +/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
> > > +/*
> > > + * Copyright (c) 2023 Neil Armstrong <neil.armstrong@linaro.org>
> > > + */
> > > +
> > > +#ifndef __MESON_HW_CLKC_H__
> > > +#define __MESON_HW_CLKC_H__
> > > +
> > > +#include <linux/of_device.h>
> > > +#include <linux/clk-provider.h>
> > > +
> > > +struct meson_clk_hw_data {
> > > +	struct clk_hw	**hws;
> > > +	unsigned int	num;
> > > +};
> > > +
> > > +struct clk_hw *meson_clk_hw_get(struct of_phandle_args *clkspec, void *clk_hw_data);
> > > +
> > > +#endif
> > > ===================================><============================================================================
> > > 
> > > If it's ok I'll send a v2 using this.
> > > 
> > > Thanks,
> > > Neil
> > 
> > In addition, I propose consolidating the probe() routine of the a1
> > clocks into a common part, which can be utilized for s4 and other
> > similar clocks. This solution was presented in the early a1 review
> > stages of this patch set.
> > 
> > https://lore.kernel.org/linux-amlogic/20221201225703.6507-7-ddrokosov@sberdevices.ru/
> > 
> > Maybe, it can be generalized for the all meson clock controller drivers.
> > 
> 
> Sure, the goal of that is to get rid of NR_CLKS & private IDS only,
> then yes afterwards any common clkc function will be welcome !
> 
> Neil
> 

Understood, I fully endorse and support this approach!

-- 
Thank you,
Dmitry