Subject: [PATCH 1/2] clk: Add composite clock type

From: [email-masked] (Stephen Boyd)
Date: Fri, 04 Jan 2013 14:18:32 -0800

On 01/03/13 21:51, Prashant Gaikwad wrote:
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index f0b269a..baf7608 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -2,7 +2,8 @@
>  obj-$(CONFIG_HAVE_CLK)		+= clk-devres.o
>  obj-$(CONFIG_CLKDEV_LOOKUP)	+= clkdev.o
>  obj-$(CONFIG_COMMON_CLK)	+= clk.o clk-fixed-rate.o clk-gate.o \
> -				   clk-mux.o clk-divider.o clk-fixed-factor.o
> +				   clk-mux.o clk-divider.o clk-fixed-factor.o \
> +				   clk-composite.o

This list is getting a little out of hand. Should we sort it
alphabetically and put each file on one line?

>  # SoCs specific
>  obj-$(CONFIG_ARCH_BCM2835)	+= clk-bcm2835.o
>  obj-$(CONFIG_ARCH_NOMADIK)	+= clk-nomadik.o
> diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c
> new file mode 100644
> index 0000000..8634dbf
> --- /dev/null
> +++ b/drivers/clk/clk-composite.c
> @@ -0,0 +1,208 @@
> +/*
> + * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope 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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/slab.h>
> +
> +#define to_clk_composite(_hw) container_of(_hw, struct clk_composite, hw)
> +
> +static u8 clk_composite_get_parent(struct clk_hw *hw)
> +{
> +	struct clk_composite *composite = to_clk_composite(hw);
> +	const struct clk_ops *mux_ops = composite->mux_ops;
> +	struct clk_hw *mux_hw = composite->mux_hw;
> +
> +	mux_hw->clk = hw->clk;

Looks like this is already done down in the register function. Why are
we doing it again here and in each op?

> +
> +	return mux_ops->get_parent(mux_hw);
> +}
[snip]
> +struct clk *clk_register_composite(struct device *dev, const char *name,
> +			const char **parent_names, int num_parents,
> +			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
> +			struct clk_hw *div_hw, const struct clk_ops *div_ops,
> +			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
> +			unsigned long flags)
> +{
> +	struct clk *clk;
> +	struct clk_init_data init;
> +	struct clk_composite *composite;
> +	struct clk_ops *clk_composite_ops;
> +
> +	composite = kzalloc(sizeof(struct clk_ops), GFP_KERNEL);

sizeof(*composite) != sizeof(struct clk_ops)

> +	if (!composite) {
> +		pr_err("%s: could not allocate composite clk\n", __func__);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	init.name = name;
> +	init.flags = flags | CLK_IS_BASIC;
> +	init.parent_names = parent_names;
> +	init.num_parents = num_parents;
> +
> +	/* allocate the clock ops */
> +	clk_composite_ops = kzalloc(sizeof(struct clk_ops), GFP_KERNEL);

This one looks right though. Perhaps you should change style to use
sizeof(*clk_composite_ops) so that the above mistake doesn't happen.

> +	if (!clk_composite_ops) {
> +		pr_err("%s: could not allocate clk ops\n", __func__);
> +		kfree(composite);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	if (mux_hw && mux_ops) {
> +		if (!mux_ops->get_parent || !mux_ops->set_parent) {
> +			clk = ERR_PTR(-EINVAL);
> +			goto err;
> +		}
> +
> +		composite->mux_hw = mux_hw;
> +		composite->mux_ops = mux_ops;
> +		clk_composite_ops->get_parent = clk_composite_get_parent;
> +		clk_composite_ops->set_parent = clk_composite_set_parent;
> +	}
> +
> +	if (div_hw && div_ops) {
> +		if (!div_ops->recalc_rate || !div_ops->round_rate ||
> +		    !div_ops->set_rate) {
> +			clk = ERR_PTR(-EINVAL);
> +			goto err;
> +		}
> +
> +		composite->div_hw = div_hw;
> +		composite->div_ops = div_ops;
> +		clk_composite_ops->recalc_rate = clk_composite_recalc_rate;
> +		clk_composite_ops->round_rate = clk_composite_round_rate;
> +		clk_composite_ops->set_rate = clk_composite_set_rate;
> +	}
> +
> +	if (gate_hw && gate_ops) {
> +		if (!gate_ops->is_enabled || !gate_ops->enable ||
> +		    !gate_ops->disable) {
> +			clk = ERR_PTR(-EINVAL);
> +			goto err;
> +		}
> +
> +		composite->gate_hw = gate_hw;
> +		composite->gate_ops = gate_ops;
> +		clk_composite_ops->is_enabled = clk_composite_is_enabled;
> +		clk_composite_ops->enable = clk_composite_enable;
> +		clk_composite_ops->disable = clk_composite_disable;
> +	}
> +
> +	init.ops = clk_composite_ops;
> +	composite->hw.init = &init;
> +
> +	clk = clk_register(NULL, &composite->hw);

Please pass dev here.

> +	if (IS_ERR(clk))
> +		goto err;
> +
> +	if (composite->mux_hw)
> +		composite->mux_hw->clk = clk;
> +
> +	if (composite->div_hw)
> +		composite->div_hw->clk = clk;
> +
> +	if (composite->gate_hw)
> +		composite->gate_hw->clk = clk;
> +
> +	return clk;
> +
> +err:
> +	kfree(clk_composite_ops);
> +	kfree(composite);
> +	return clk;
> +}
>

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