Subject: [PATCH v2] clk: mediatek: Export CPU mux clocks for CPU frequency control

From: [email-masked] (Stephen Boyd)
Date: Fri, 15 May 2015 12:00:58 -0700

On 04/20, pi-cheng.chen wrote:
> Signed-off-by: pi-cheng.chen <[email-masked]>
> diff --git a/drivers/clk/mediatek/clk-cpumux.c b/drivers/clk/mediatek/clk-cpumux.c
> new file mode 100644
> index 0000000..dc14074
> --- /dev/null
> +++ b/drivers/clk/mediatek/clk-cpumux.c
> @@ -0,0 +1,122 @@
> +/*
> + * Copyright (c) 2015 Linaro Ltd.
> + * Author: Pi-Cheng Chen <[email-masked]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>

Do you need this include for some reason?

> +#include <linux/clk-provider.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/slab.h>
> +
> +#include "clk-mtk.h"
> +#include "clk-cpumux.h"
> +
[...]
> +
> +static struct clk_ops clk_cpumux_ops = {

const?

> +	.get_parent = clk_cpumux_get_parent,
> +	.set_parent = clk_cpumux_set_parent,
> +};
> +
> +static struct clk *mtk_clk_register_cpumux(const struct mtk_composite *mux,
> +					   struct regmap *regmap)
> +{
> +	struct mtk_clk_cpumux *cpumux;
> +	struct clk *clk;
> +	struct clk_init_data init;
> +
> +	cpumux = kzalloc(sizeof(*cpumux), GFP_KERNEL);
> +	if (!cpumux)
> +		return ERR_PTR(-ENOMEM);
> +
> +	init.name = mux->name;
> +	init.ops = &clk_cpumux_ops;
> +	init.parent_names = mux->parent_names;
> +	init.num_parents = mux->num_parents;
> +
> +	cpumux->reg = mux->mux_reg;
> +	cpumux->shift = mux->mux_shift;
> +	cpumux->mask = (BIT(mux->mux_width) - 1);

Unnecessary parenthesis.

> +	cpumux->regmap = regmap;
> +	cpumux->hw.init = &init;
> +
> +	clk = clk_register(NULL, &cpumux->hw);
> +	if (IS_ERR(clk))
> +		kfree(cpumux);
> +
> +	return clk;
> +}
> +
> +int mtk_clk_register_cpumuxes(struct device_node *node,
> +			      const struct mtk_composite *clks, int num,
> +			      struct clk_onecell_data *clk_data)
> +{
> +	int i;
> +	struct clk *clk;
> +	struct regmap *regmap;
> +
> +	if (!clk_data)
> +		return -ENOMEM;

Why would we call the function with NULL clk_data? Please remove
this check.

> +
> +	regmap = syscon_node_to_regmap(node);
> +	if (IS_ERR(regmap)) {
> +		pr_err("Cannot find regmap for %s: %ld\n", node->full_name,
> +		       PTR_ERR(regmap));
> +		return PTR_ERR(regmap);
> +	}
> +
> diff --git a/drivers/clk/mediatek/clk-cpumux.h b/drivers/clk/mediatek/clk-cpumux.h
> new file mode 100644
> index 0000000..b82ad20
> --- /dev/null
> +++ b/drivers/clk/mediatek/clk-cpumux.h
> @@ -0,0 +1,31 @@
> +/*
> + * Copyright (c) 2015 Linaro Ltd.
> + * Author: Pi-Cheng Chen <[email-masked]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef __DRV_CLK_CPUMUX_H
> +#define __DRV_CLK_CPUMUX_H
> +
> +#include <linux/regmap.h>

Looks unnecessary. Just forward declare the type you need, struct
regmap.

> +
> +struct mtk_clk_cpumux {
> +	struct clk_hw	hw;
> +	struct regmap	*regmap;
> +	u32		reg;
> +	u32		mask;
> +	u8		shift;
> +};
> +
> +int mtk_clk_register_cpumuxes(struct device_node *node,
> +			      const struct mtk_composite *clks, int num,
> +			      struct clk_onecell_data *clk_data);
> +#endif /* __DRV_CLK_CPUMUX_H */

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