[v8,06/11] clk: meson: introduce a1-clkc common driver for all A1 clock controllers

  Generally, A1 SoC has four clock controllers on the board: PLL,
Peripherals, CPU, and Audio. The audio clock controller is different
from others, but the rest are very similar from a functional and regmap
point of view. So a it's good idea to generalize some routines for all
of them. Exactly, meson-a1-clkc driver contains the common probe() flow.

Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
---
 drivers/clk/meson/Kconfig         |  4 ++
 drivers/clk/meson/Makefile        |  1 +
 drivers/clk/meson/meson-a1-clkc.c | 63 +++++++++++++++++++++++++++++++
 drivers/clk/meson/meson-a1-clkc.h | 25 ++++++++++++
 4 files changed, 93 insertions(+)
 create mode 100644 drivers/clk/meson/meson-a1-clkc.c
 create mode 100644 drivers/clk/meson/meson-a1-clkc.h
  

On Fri 02 Dec 2022 at 01:56, Dmitry Rokosov <ddrokosov@sberdevices.ru> wrote:

> Generally, A1 SoC has four clock controllers on the board: PLL,
> Peripherals, CPU, and Audio. The audio clock controller is different
> from others, but the rest are very similar from a functional and regmap
> point of view. So a it's good idea to generalize some routines for all
> of them. Exactly, meson-a1-clkc driver contains the common probe() flow.
>
> Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>

I think you should leave this out for the initial submission. It makes
harder to review.

In some case, these factorizations actually the maitenance harder.

There is also the s4 that is coming up. It looks similar to the A1 as
well.

Let's wait for both them to land, see how it goes and then we'll decide
if a factorization is appropriate.

> ---
>  drivers/clk/meson/Kconfig         |  4 ++
>  drivers/clk/meson/Makefile        |  1 +
>  drivers/clk/meson/meson-a1-clkc.c | 63 +++++++++++++++++++++++++++++++
>  drivers/clk/meson/meson-a1-clkc.h | 25 ++++++++++++
>  4 files changed, 93 insertions(+)
>  create mode 100644 drivers/clk/meson/meson-a1-clkc.c
>  create mode 100644 drivers/clk/meson/meson-a1-clkc.h
>
> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
> index bd44ba47200e..1c885541c3a9 100644
> --- a/drivers/clk/meson/Kconfig
> +++ b/drivers/clk/meson/Kconfig
> @@ -43,6 +43,10 @@ config COMMON_CLK_MESON_CPU_DYNDIV
>  	tristate
>  	select COMMON_CLK_MESON_REGMAP
>  
> +config COMMON_CLK_MESON_A1_CLKC
> +	tristate
> +	select COMMON_CLK_MESON_REGMAP
> +
>  config COMMON_CLK_MESON8B
>  	bool "Meson8 SoC Clock controller support"
>  	depends on ARM
> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
> index 0e6f293c05d4..15136d861a65 100644
> --- a/drivers/clk/meson/Makefile
> +++ b/drivers/clk/meson/Makefile
> @@ -11,6 +11,7 @@ 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_A1_CLKC) += meson-a1-clkc.o
>  
>  # Amlogic Clock controllers
>  
> diff --git a/drivers/clk/meson/meson-a1-clkc.c b/drivers/clk/meson/meson-a1-clkc.c
> new file mode 100644
> index 000000000000..2fe320a0e16e
> --- /dev/null
> +++ b/drivers/clk/meson/meson-a1-clkc.c
> @@ -0,0 +1,63 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Amlogic Meson-A1 Clock Controller Driver
> + *
> + * Copyright (c) 2022, SberDevices. All Rights Reserved.
> + * Author: Dmitry Rokosov <ddrokosov@sberdevices.ru>
> + */
> +
> +#include <linux/of_device.h>
> +#include "meson-a1-clkc.h"
> +
> +static struct regmap_config clkc_regmap_config = {
> +	.reg_bits   = 32,
> +	.val_bits   = 32,
> +	.reg_stride = 4,
> +};
> +
> +int meson_a1_clkc_probe(struct platform_device *pdev)
> +{
> +	struct meson_a1_clkc_data *clkc;
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	void __iomem *base;
> +	struct regmap *map;
> +	int clkid, i, err;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res)
> +		return dev_err_probe(dev, -ENXIO, "can't get IO resource\n");
> +
> +	base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(base))
> +		return dev_err_probe(dev, PTR_ERR(base),
> +				     "can't ioremap resource %pr\n", res);
> +
> +	map = devm_regmap_init_mmio(dev, base, &clkc_regmap_config);
> +	if (IS_ERR(map))
> +		return dev_err_probe(dev, PTR_ERR(map),
> +				     "can't init regmap mmio region\n");
> +
> +	clkc = (struct meson_a1_clkc_data *)of_device_get_match_data(dev);
> +	if (!clkc)
> +		return dev_err_probe(dev, -ENODEV,
> +				     "can't get A1 clkc driver data\n");
> +
> +	/* Populate regmap for the regmap backed clocks */
> +	for (i = 0; i < clkc->num_regs; i++)
> +		clkc->regs[i]->map = map;
> +
> +	for (clkid = 0; clkid < clkc->hw->num; clkid++) {
> +		err = devm_clk_hw_register(dev, clkc->hw->hws[clkid]);
> +		if (err)
> +			return dev_err_probe(dev, err,
> +					     "clock registration failed\n");
> +	}
> +
> +	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
> +					   (void *)clkc->hw);
> +}
> +EXPORT_SYMBOL_GPL(meson_a1_clkc_probe);
> +
> +MODULE_AUTHOR("Dmitry Rokosov <ddrokosov@sberdevices.ru>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/clk/meson/meson-a1-clkc.h b/drivers/clk/meson/meson-a1-clkc.h
> new file mode 100644
> index 000000000000..503eca0f6cb5
> --- /dev/null
> +++ b/drivers/clk/meson/meson-a1-clkc.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
> +/*
> + * Amlogic Meson-A1 Clock Controller driver
> + *
> + * Copyright (c) 2022, SberDevices. All Rights Reserved.
> + * Author: Dmitry Rokosov <ddrokosov@sberdevices.ru>
> + */
> +
> +#ifndef __MESON_A1_CLKC_H__
> +#define __MESON_A1_CLKC_H__
> +
> +#include <linux/clk-provider.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#include "clk-regmap.h"
> +
> +struct meson_a1_clkc_data {
> +	const struct clk_hw_onecell_data *hw;
> +	struct clk_regmap *const *regs;
> +	size_t num_regs;
> +};
> +
> +int meson_a1_clkc_probe(struct platform_device *pdev);
> +#endif
  

On Fri, Dec 02, 2022 at 12:36:50PM +0100, Jerome Brunet wrote:
> 
> On Fri 02 Dec 2022 at 01:56, Dmitry Rokosov <ddrokosov@sberdevices.ru> wrote:
> 
> > Generally, A1 SoC has four clock controllers on the board: PLL,
> > Peripherals, CPU, and Audio. The audio clock controller is different
> > from others, but the rest are very similar from a functional and regmap
> > point of view. So a it's good idea to generalize some routines for all
> > of them. Exactly, meson-a1-clkc driver contains the common probe() flow.
> >
> > Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
> 
> I think you should leave this out for the initial submission. It makes
> harder to review.
> 
> In some case, these factorizations actually the maitenance harder.
> 
> There is also the s4 that is coming up. It looks similar to the A1 as
> well.
> 
> Let's wait for both them to land, see how it goes and then we'll decide
> if a factorization is appropriate.
> 

Jerome,

Sorry, let me double check a little bit that I get your point correctly.

Do you mean due to s4 development in parallel it's easier to have own
probe sequence for each driver in the first stage (until A1 and S4 clock
controllers not merged to upstream) and after think about some
"generalization", right?

...