linux-kernel - Re: [PATCH v3 1/5] clk: sunxi: Add CLK_OF_DECLARE support for sun8i-a23-apb0-clk driver

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Message-ID: <20151125141822.GM32142@lukather>
Date:	Wed, 25 Nov 2015 15:18:22 +0100
From:	Maxime Ripard <maxime.ripard@...e-electrons.com>
To:	Chen-Yu Tsai <wens@...e.org>
Cc:	Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...eaurora.org>,
	Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>, linux-clk@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-sunxi@...glegroups.com
Subject: Re: [PATCH v3 1/5] clk: sunxi: Add CLK_OF_DECLARE support for
 sun8i-a23-apb0-clk driver

On Tue, Nov 24, 2015 at 05:32:12PM +0800, Chen-Yu Tsai wrote:
> The APBS clock on sun9i is the same as the APB0 clock on sun8i. With
> sun9i we are supporting the PRCM clocks by using CLK_OF_DECLARE,
> instead of through a PRCM mfd device and subdevices for each clock
> and reset control. As such we need a CLK_OF_DECLARE version of
> the sun8i-a23-apb0-clk driver.
> 
> Also, build it for all Allwinner/sunxi platforms, and not just for
> configurations with MFD_SUN6I_PRCM enabled.
> 
> Signed-off-by: Chen-Yu Tsai <wens@...e.org>
> ---
>  drivers/clk/sunxi/Makefile         |  4 ++--
>  drivers/clk/sunxi/clk-sun8i-apb0.c | 43 ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 45 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> index cb4c299214ce..121333ce34ea 100644
> --- a/drivers/clk/sunxi/Makefile
> +++ b/drivers/clk/sunxi/Makefile
> @@ -10,11 +10,11 @@ obj-y += clk-a10-pll2.o
>  obj-y += clk-a20-gmac.o
>  obj-y += clk-mod0.o
>  obj-y += clk-simple-gates.o
> +obj-y += clk-sun8i-apb0.o
>  obj-y += clk-sun8i-mbus.o
>  obj-y += clk-sun9i-core.o
>  obj-y += clk-sun9i-mmc.o
>  obj-y += clk-usb.o
>  
>  obj-$(CONFIG_MFD_SUN6I_PRCM) += \
> -	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
> -	clk-sun8i-apb0.o
> +	clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o

I'd really prefer not to build a driver that is used only on a few
SoCs if the support for these SoCs are not even enabled.

> diff --git a/drivers/clk/sunxi/clk-sun8i-apb0.c b/drivers/clk/sunxi/clk-sun8i-apb0.c
> index 7ae5d2c2cde1..11b2f2fde245 100644
> --- a/drivers/clk/sunxi/clk-sun8i-apb0.c
> +++ b/drivers/clk/sunxi/clk-sun8i-apb0.c
> @@ -17,8 +17,51 @@
>  #include <linux/clk-provider.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> +#include <linux/of_address.h>
>  #include <linux/platform_device.h>
>  
> +static void sun8i_a23_apb0_setup(struct device_node *node)
> +{
> +	const char *clk_name = node->name;
> +	const char *clk_parent;
> +	void __iomem *reg;
> +	struct resource res;
> +	struct clk *clk;
> +	int ret;
> +
> +	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
> +	if (IS_ERR(reg))
> +		return;
> +
> +	clk_parent = of_clk_get_parent_name(node, 0);
> +	if (!clk_parent)
> +		goto err_unmap;
> +
> +	of_property_read_string(node, "clock-output-names", &clk_name);
> +
> +	/* The A23 APB0 clock is a standard 2 bit wide divider clock */
> +	clk = clk_register_divider(NULL, clk_name, clk_parent, 0, reg,
> +				   0, 2, CLK_DIVIDER_POWER_OF_TWO, NULL);
> +	if (IS_ERR(clk))
> +		goto err_unmap;
> +
> +	ret = of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +	if (ret)
> +		goto err_unregister;
> +
> +	return;
> +
> +err_unregister:
> +	clk_unregister_divider(clk);
> +
> +err_unmap:
> +	iounmap(reg);
> +	of_address_to_resource(node, 0, &res);
> +	release_mem_region(res.start, resource_size(&res));
> +}
> +CLK_OF_DECLARE(sun8i_a23_apb0, "allwinner,sun8i-a23-apb0-clk",
> +	       sun8i_a23_apb0_setup);

So, beside the memory request / mapping, everything else is
duplicated? Can't you just create a common function and call it from
both?

Thanks,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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