[PATCH v9 07/12] clk: meson: add vclk driver
Jerome Brunet
jbrunet at baylibre.com
Fri Nov 24 06:41:07 PST 2023
On Fri 24 Nov 2023 at 09:41, Neil Armstrong <neil.armstrong at linaro.org> wrote:
> The VCLK and VCLK_DIV clocks have supplementary bits.
>
> The VCLK has a "SOFT RESET" bit to toggle after the whole
> VCLK sub-tree rate has been set, this is implemented in
> the gate enable callback.
>
> The VCLK_DIV clocks as enable and reset bits used to disable
> and reset the divider, associated with CLK_SET_RATE_GATE it ensures
> the rate is set while the divider is disabled and in reset mode.
>
> The VCLK_DIV enable bit isn't implemented as a gate since it's part
> of the divider logic and vendor does this exact sequence to ensure
> the divider is correctly set.
>
> Signed-off-by: Neil Armstrong <neil.armstrong at linaro.org>
> ---
> drivers/clk/meson/Kconfig | 5 ++
> drivers/clk/meson/Makefile | 1 +
> drivers/clk/meson/vclk.c | 141 +++++++++++++++++++++++++++++++++++++++++++++
> drivers/clk/meson/vclk.h | 51 ++++++++++++++++
> 4 files changed, 198 insertions(+)
>
> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
> index 29ffd14d267b..59a40a49f8e1 100644
> --- a/drivers/clk/meson/Kconfig
> +++ b/drivers/clk/meson/Kconfig
> @@ -30,6 +30,10 @@ config COMMON_CLK_MESON_VID_PLL_DIV
> tristate
> select COMMON_CLK_MESON_REGMAP
>
> +config COMMON_CLK_MESON_VCLK
> + tristate
> + select COMMON_CLK_MESON_REGMAP
> +
> config COMMON_CLK_MESON_CLKC_UTILS
> tristate
>
> @@ -140,6 +144,7 @@ config COMMON_CLK_G12A
> select COMMON_CLK_MESON_EE_CLKC
> select COMMON_CLK_MESON_CPU_DYNDIV
> select COMMON_CLK_MESON_VID_PLL_DIV
> + select COMMON_CLK_MESON_VCLK
This particular line belong in the next patch
> select MFD_SYSCON
> help
> Support for the clock controller on Amlogic S905D2, S905X2 and S905Y2
> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
> index 9ee4b954c896..9ba43fe7a07a 100644
> --- a/drivers/clk/meson/Makefile
> +++ b/drivers/clk/meson/Makefile
> @@ -12,6 +12,7 @@ obj-$(CONFIG_COMMON_CLK_MESON_PLL) += clk-pll.o
> obj-$(CONFIG_COMMON_CLK_MESON_REGMAP) += clk-regmap.o
> obj-$(CONFIG_COMMON_CLK_MESON_SCLK_DIV) += sclk-div.o
> obj-$(CONFIG_COMMON_CLK_MESON_VID_PLL_DIV) += vid-pll-div.o
> +obj-$(CONFIG_COMMON_CLK_MESON_VCLK) += vclk.o
>
> # Amlogic Clock controllers
>
> diff --git a/drivers/clk/meson/vclk.c b/drivers/clk/meson/vclk.c
> new file mode 100644
> index 000000000000..47f08a52b49f
> --- /dev/null
> +++ b/drivers/clk/meson/vclk.c
> @@ -0,0 +1,141 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2023 Neil Armstrong <neil.armstrong at linaro.org>
> + */
> +
> +#include <linux/module.h>
> +#include "vclk.h"
> +
> +/* The VCLK gate has a supplementary reset bit to pulse after ungating */
> +
> +static inline struct clk_regmap_vclk_data *
> +clk_get_regmap_vclk_data(struct clk_regmap *clk)
> +{
> + return (struct clk_regmap_vclk_data *)clk->data;
> +}
> +
> +static int clk_regmap_vclk_enable(struct clk_hw *hw)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_data *vclk = clk_get_regmap_vclk_data(clk);
> +
> + meson_parm_write(clk->map, &vclk->enable, 1);
> +
> + /* Do a reset pulse */
> + meson_parm_write(clk->map, &vclk->reset, 1);
> + meson_parm_write(clk->map, &vclk->reset, 0);
> +
> + return 0;
> +}
> +
> +static void clk_regmap_vclk_disable(struct clk_hw *hw)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_data *vclk = clk_get_regmap_vclk_data(clk);
> +
> + meson_parm_write(clk->map, &vclk->enable, 0);
> +}
> +
> +static int clk_regmap_vclk_is_enabled(struct clk_hw *hw)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_data *vclk = clk_get_regmap_vclk_data(clk);
> +
> + return meson_parm_read(clk->map, &vclk->enable);
> +}
> +
> +const struct clk_ops clk_regmap_vclk_ops = {
> + .enable = clk_regmap_vclk_enable,
> + .disable = clk_regmap_vclk_disable,
> + .is_enabled = clk_regmap_vclk_is_enabled,
> +};
> +EXPORT_SYMBOL_GPL(clk_regmap_vclk_ops);
s/clk_regmap_vclk/meson_vclk at least for what is exported, ideally most
all the code.
I get clk_regmap_ comes from code copied from clk_regmap.c.
The reason the this part is different (and not using parm) if that when
I converted amlogic to regmap, I hope we could make this generic,
possibly converging between aml and qcom (which was the only other
platform using regmap for clock at the time). This is why clk_regmap.c
is a bit different from the other driver.
For the aml specific drivers, best to look at the mpll or cpu-dyndiv one.
> +
> +/* The VCLK Divider has supplementary reset & enable bits */
> +
> +static inline struct clk_regmap_vclk_div_data *
> +clk_get_regmap_vclk_div_data(struct clk_regmap *clk)
> +{
> + return (struct clk_regmap_vclk_div_data *)clk->data;
> +}
> +
> +static unsigned long clk_regmap_vclk_div_recalc_rate(struct clk_hw *hw,
> + unsigned long prate)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_div_data *vclk = clk_get_regmap_vclk_div_data(clk);
> +
> + return divider_recalc_rate(hw, prate, meson_parm_read(clk->map, &vclk->div),
> + vclk->table, vclk->flags, vclk->div.width);
> +}
> +
> +static int clk_regmap_vclk_div_determine_rate(struct clk_hw *hw,
> + struct clk_rate_request *req)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_div_data *vclk = clk_get_regmap_vclk_div_data(clk);
> +
> + return divider_determine_rate(hw, req, vclk->table, vclk->div.width,
> + vclk->flags);
> +}
> +
> +static int clk_regmap_vclk_div_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_div_data *vclk = clk_get_regmap_vclk_div_data(clk);
> + int ret;
> +
> + ret = divider_get_val(rate, parent_rate, vclk->table, vclk->div.width,
> + vclk->flags);
> + if (ret < 0)
> + return ret;
> +
> + meson_parm_write(clk->map, &vclk->div, ret);
> +
> + return 0;
> +};
> +
> +static int clk_regmap_vclk_div_enable(struct clk_hw *hw)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_div_data *vclk = clk_get_regmap_vclk_div_data(clk);
> +
> + /* Unreset the divider when ungating */
> + meson_parm_write(clk->map, &vclk->reset, 0);
> + meson_parm_write(clk->map, &vclk->enable, 1);
> +
> + return 0;
> +}
> +
> +static void clk_regmap_vclk_div_disable(struct clk_hw *hw)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_div_data *vclk = clk_get_regmap_vclk_div_data(clk);
> +
> + /* Reset the divider when gating */
> + meson_parm_write(clk->map, &vclk->enable, 0);
> + meson_parm_write(clk->map, &vclk->reset, 1);
> +}
> +
> +static int clk_regmap_vclk_div_is_enabled(struct clk_hw *hw)
> +{
> + struct clk_regmap *clk = to_clk_regmap(hw);
> + struct clk_regmap_vclk_div_data *vclk = clk_get_regmap_vclk_div_data(clk);
> +
> + return meson_parm_read(clk->map, &vclk->enable);
> +}
> +
> +const struct clk_ops clk_regmap_vclk_div_ops = {
> + .recalc_rate = clk_regmap_vclk_div_recalc_rate,
> + .determine_rate = clk_regmap_vclk_div_determine_rate,
> + .set_rate = clk_regmap_vclk_div_set_rate,
> + .enable = clk_regmap_vclk_div_enable,
> + .disable = clk_regmap_vclk_div_disable,
> + .is_enabled = clk_regmap_vclk_div_is_enabled,
> +};
> +EXPORT_SYMBOL_GPL(clk_regmap_vclk_div_ops);
> +
> +MODULE_DESCRIPTION("Amlogic vclk clock driver");
> +MODULE_AUTHOR("Neil Armstrong <neil.armstrong at linaro.org>");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/clk/meson/vclk.h b/drivers/clk/meson/vclk.h
> new file mode 100644
> index 000000000000..4f25d7ad2717
> --- /dev/null
> +++ b/drivers/clk/meson/vclk.h
> @@ -0,0 +1,51 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2023 Neil Armstrong <neil.armstrong at linaro.org>
> + */
> +
> +#ifndef __VCLK_H
> +#define __VCLK_H
This is too generic.
Please add the MESON prefix like the other clock driver please.
> +
> +#include "clk-regmap.h"
> +#include "parm.h"
> +
> +/**
> + * struct clk_regmap_vclk_data - vclk regmap backed specific data
> + *
> + * @enable: vclk enable field
> + * @reset: vclk reset field
> + * @flags: hardware-specific flags
> + *
> + * Flags:
> + * Same as clk_gate except CLK_GATE_HIWORD_MASK which is ignored
> + */
> +struct clk_regmap_vclk_data {
> + struct parm enable;
> + struct parm reset;
> + u8 flags;
> +};
> +
> +extern const struct clk_ops clk_regmap_vclk_ops;
> +
> +/**
> + * struct clk_regmap_vclk_div_data - vclk_div regmap back specific data
> + *
> + * @div: divider field
> + * @enable: vclk divider enable field
> + * @reset: vclk divider reset field
> + * @table: array of value/divider pairs, last entry should have div = 0
> + *
> + * Flags:
> + * Same as clk_divider except CLK_DIVIDER_HIWORD_MASK which is ignored
> + */
> +struct clk_regmap_vclk_div_data {
> + struct parm div;
> + struct parm enable;
> + struct parm reset;
> + const struct clk_div_table *table;
> + u8 flags;
> +};
> +
> +extern const struct clk_ops clk_regmap_vclk_div_ops;
> +
> +#endif /* __VCLK_H */
More information about the linux-amlogic
mailing list