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

From: Stephen Boyd
Date: Fri May 15 2015 - 15:01:18 EST


On 04/20, pi-cheng.chen wrote:
> Signed-off-by: pi-cheng.chen <pi-cheng.chen@xxxxxxxxxx>
> 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 <pi-cheng.chen@xxxxxxxxxx>
> + *
> + * 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 <pi-cheng.chen@xxxxxxxxxx>
> + *
> + * 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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