linux-kernel - Re: [PATCH 2/7] clk: meson: add clk-phase clock driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <86b8e8f5-fb69-3249-fc1e-b4f2213284db@baylibre.com>
Date:   Thu, 26 Apr 2018 10:46:12 +0200
From:   Neil Armstrong <narmstrong@...libre.com>
To:     Jerome Brunet <jbrunet@...libre.com>,
        Carlo Caione <carlo@...one.org>,
        Kevin Hilman <khilman@...libre.com>
Cc:     Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        linux-amlogic@...ts.infradead.org, linux-clk@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/7] clk: meson: add clk-phase clock driver

On 25/04/2018 18:32, Jerome Brunet wrote:
> Add a driver based meson clk-regmap to control clock phase on
> amlogic SoCs
> 
> Signed-off-by: Jerome Brunet <jbrunet@...libre.com>
> ---
>  drivers/clk/meson/Makefile    |  1 +
>  drivers/clk/meson/clk-phase.c | 63 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/clk/meson/clkc.h      |  8 ++++++
>  3 files changed, 72 insertions(+)
>  create mode 100644 drivers/clk/meson/clk-phase.c
> 
> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
> index ffee82e60b7a..352fb848c406 100644
> --- a/drivers/clk/meson/Makefile
> +++ b/drivers/clk/meson/Makefile
> @@ -3,6 +3,7 @@
>  #
>  
>  obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-audio-divider.o
> +obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-phase.o
>  obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
>  obj-$(CONFIG_COMMON_CLK_GXBB)	 += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o
>  obj-$(CONFIG_COMMON_CLK_AXG)	 += axg.o
> diff --git a/drivers/clk/meson/clk-phase.c b/drivers/clk/meson/clk-phase.c
> new file mode 100644
> index 000000000000..96e70497ef1b
> --- /dev/null
> +++ b/drivers/clk/meson/clk-phase.c
> @@ -0,0 +1,63 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Copyright (c) 2018 BayLibre, SAS.
> + * Author: Jerome Brunet <jbrunet@...libre.com>
> + */
> +
> +#include <linux/clk-provider.h>
> +#include "clkc.h"
> +
> +#define phase_step(_width) (360 / (1 << (_width)))
> +
> +static inline struct meson_clk_phase_data *
> +meson_clk_phase_data(struct clk_regmap *clk)
> +{
> +	return (struct meson_clk_phase_data *)clk->data;
> +}
> +
> +int meson_clk_degrees_from_val(unsigned int val, unsigned int width)
> +{
> +	return phase_step(width) * val;
> +}
> +EXPORT_SYMBOL_GPL(meson_clk_degrees_from_val);
> +
> +unsigned int meson_clk_degrees_to_val(int degrees, unsigned int width)
> +{
> +	unsigned int val = DIV_ROUND_CLOSEST(degrees, phase_step(width));
> +
> +	/*
> +	 * This last calculation is here for cases when degrees is rounded
> +	 * to 360, in which case val == (1 << width).
> +	 */
> +	return val % (1 << width);
> +}
> +EXPORT_SYMBOL_GPL(meson_clk_degrees_to_val);
> +
> +static int meson_clk_phase_get_phase(struct clk_hw *hw)
> +{
> +	struct clk_regmap *clk = to_clk_regmap(hw);
> +	struct meson_clk_phase_data *phase = meson_clk_phase_data(clk);
> +	unsigned int val;
> +
> +	val = meson_parm_read(clk->map, &phase->ph);
> +
> +	return meson_clk_degrees_from_val(val, phase->ph.width);
> +}
> +
> +static int meson_clk_phase_set_phase(struct clk_hw *hw, int degrees)
> +{
> +	struct clk_regmap *clk = to_clk_regmap(hw);
> +	struct meson_clk_phase_data *phase = meson_clk_phase_data(clk);
> +	unsigned int val;
> +
> +	val = meson_clk_degrees_to_val(degrees, phase->ph.width);
> +	meson_parm_write(clk->map, &phase->ph, val);
> +
> +	return 0;
> +}
> +
> +const struct clk_ops meson_clk_phase_ops = {
> +	.get_phase	= meson_clk_phase_get_phase,
> +	.set_phase	= meson_clk_phase_set_phase,
> +};
> +EXPORT_SYMBOL_GPL(meson_clk_phase_ops);
> diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
> index 8fe73c4edca8..9a17d6705e0a 100644
> --- a/drivers/clk/meson/clkc.h
> +++ b/drivers/clk/meson/clkc.h
> @@ -104,6 +104,13 @@ struct meson_clk_audio_div_data {
>  	u8 flags;
>  };
>  
> +struct meson_clk_phase_data {
> +	struct parm ph;
> +};
> +
> +int meson_clk_degrees_from_val(unsigned int val, unsigned int width);
> +unsigned int meson_clk_degrees_to_val(int degrees, unsigned int width);
> +
>  #define MESON_GATE(_name, _reg, _bit)					\
>  struct clk_regmap _name = {						\
>  	.data = &(struct clk_regmap_gate_data){				\
> @@ -127,5 +134,6 @@ extern const struct clk_ops meson_clk_mpll_ro_ops;
>  extern const struct clk_ops meson_clk_mpll_ops;
>  extern const struct clk_ops meson_clk_audio_divider_ro_ops;
>  extern const struct clk_ops meson_clk_audio_divider_ops;
> +extern const struct clk_ops meson_clk_phase_ops;
>  
>  #endif /* __CLKC_H */
> 

Acked-by: Neil Armstrong <narmstrong@...libre.com>