Re: [PATCH 22/22] clk: mediatek: Add MT8195 apusys clock support

[Chen-Yu Tsai <wenst@chromium.org>]

Hi,

On Thu, Jun 17, 2021 at 7:00 AM Chun-Jie Chen
<chun-jie.chen@mediatek.com> wrote:
>
> Add MT8195 apusys clock provider
>
> Signed-off-by: Chun-Jie Chen <chun-jie.chen@mediatek.com>
> ---
>  drivers/clk/mediatek/Kconfig                 |  6 ++
>  drivers/clk/mediatek/Makefile                |  1 +
>  drivers/clk/mediatek/clk-mt8195-apusys_pll.c | 84 ++++++++++++++++++++
>  3 files changed, 91 insertions(+)
>  create mode 100644 drivers/clk/mediatek/clk-mt8195-apusys_pll.c
>
> diff --git a/drivers/clk/mediatek/Kconfig b/drivers/clk/mediatek/Kconfig
> index ade85a52b7ed..9bd1ebff61f2 100644
> --- a/drivers/clk/mediatek/Kconfig
> +++ b/drivers/clk/mediatek/Kconfig
> @@ -690,6 +690,12 @@ config COMMON_CLK_MT8195_IMP_IIC_WRAP
>         help
>           This driver supports MediaTek MT8195 imp_iic_wrap clocks.
>
> +config COMMON_CLK_MT8195_APUSYS_PLL
> +       bool "Clock driver for MediaTek MT8195 apusys_pll"
> +       depends on COMMON_CLK_MT8195
> +       help
> +         This driver supports MediaTek MT8195 apusys_pll clocks.
> +
>  config COMMON_CLK_MT8516
>         bool "Clock driver for MediaTek MT8516"
>         depends on ARCH_MEDIATEK || COMPILE_TEST
> diff --git a/drivers/clk/mediatek/Makefile b/drivers/clk/mediatek/Makefile
> index b10c6267ba98..676ed7d665b7 100644
> --- a/drivers/clk/mediatek/Makefile
> +++ b/drivers/clk/mediatek/Makefile
> @@ -98,5 +98,6 @@ obj-$(CONFIG_COMMON_CLK_MT8195_VPPSYS0) += clk-mt8195-vpp0.o
>  obj-$(CONFIG_COMMON_CLK_MT8195_VPPSYS1) += clk-mt8195-vpp1.o
>  obj-$(CONFIG_COMMON_CLK_MT8195_WPESYS) += clk-mt8195-wpe.o
>  obj-$(CONFIG_COMMON_CLK_MT8195_IMP_IIC_WRAP) += clk-mt8195-imp_iic_wrap.o
> +obj-$(CONFIG_COMMON_CLK_MT8195_APUSYS_PLL) += clk-mt8195-apusys_pll.o
>  obj-$(CONFIG_COMMON_CLK_MT8516) += clk-mt8516.o
>  obj-$(CONFIG_COMMON_CLK_MT8516_AUDSYS) += clk-mt8516-aud.o
> diff --git a/drivers/clk/mediatek/clk-mt8195-apusys_pll.c b/drivers/clk/mediatek/clk-mt8195-apusys_pll.c
> new file mode 100644
> index 000000000000..d9b49cf71281
> --- /dev/null
> +++ b/drivers/clk/mediatek/clk-mt8195-apusys_pll.c
> @@ -0,0 +1,84 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +//
> +// Copyright (c) 2021 MediaTek Inc.
> +// Author: Chun-Jie Chen <chun-jie.chen@mediatek.com>
> +
> +#include <linux/clk-provider.h>
> +#include <linux/platform_device.h>
> +
> +#include "clk-mtk.h"
> +#include "clk-gate.h"
> +
> +#include <dt-bindings/clock/mt8195-clk.h>
> +
> +#define MT8195_PLL_FMAX                (3800UL * MHZ)
> +#define MT8195_PLL_FMIN                (1500UL * MHZ)
> +#define MT8195_INTEGER_BITS    8
> +
> +#define PLL(_id, _name, _reg, _pwr_reg, _en_mask, _flags,      \
> +                       _rst_bar_mask, _pcwbits, _pd_reg, _pd_shift,    \
> +                       _tuner_reg, _tuner_en_reg, _tuner_en_bit,       \
> +                       _pcw_reg, _pcw_shift, _pcw_chg_reg,                             \
> +                       _en_reg, _pll_en_bit) {                                 \

Some of these fields are always set to zero in this driver. Either they
use the same value, or it means the particular function is not supported
in the hardware.

You could move the fixed value for unsupported functions, such as rst_bar_mask,
or even all common values, into the macro to simplify the macro argument list.
And if you do so, please also add comments explaining which values are shared,
and why they can be shared.

I believe the same could also be done for the APLL driver.

> +               .id = _id,                                              \
> +               .name = _name,                                          \
> +               .reg = _reg,                                            \
> +               .pwr_reg = _pwr_reg,                                    \
> +               .en_mask = _en_mask,                                    \
> +               .flags = _flags,                                        \
> +               .rst_bar_mask = _rst_bar_mask,                          \
> +               .fmax = MT8195_PLL_FMAX,                                \
> +               .fmin = MT8195_PLL_FMIN,                                \
> +               .pcwbits = _pcwbits,                                    \
> +               .pcwibits = MT8195_INTEGER_BITS,                        \
> +               .pd_reg = _pd_reg,                                      \
> +               .pd_shift = _pd_shift,                                  \
> +               .tuner_reg = _tuner_reg,                                \
> +               .tuner_en_reg = _tuner_en_reg,                          \
> +               .tuner_en_bit = _tuner_en_bit,                          \
> +               .pcw_reg = _pcw_reg,                                    \
> +               .pcw_shift = _pcw_shift,                                \
> +               .pcw_chg_reg = _pcw_chg_reg,                            \
> +               .en_reg = _en_reg,                                      \
> +               .pll_en_bit = _pll_en_bit,                              \
> +       }
> +
> +static const struct mtk_pll_data apusys_plls[] = {
> +       PLL(CLK_APUSYS_PLL_APUPLL, "apusys_pll_apupll", 0x008, 0x014, 0,
> +               0, 0, 22, 0x00c, 24, 0, 0, 0, 0x00c, 0, 0, 0, 0),
> +       PLL(CLK_APUSYS_PLL_NPUPLL, "apusys_pll_npupll", 0x018, 0x024, 0,
> +               0, 0, 22, 0x01c, 24, 0, 0, 0, 0x01c, 0, 0, 0, 0),
> +       PLL(CLK_APUSYS_PLL_APUPLL1, "apusys_pll_apupll1", 0x028, 0x034, 0,
> +               0, 0, 22, 0x02c, 24, 0, 0, 0, 0x02c, 0, 0, 0, 0),
> +       PLL(CLK_APUSYS_PLL_APUPLL2, "apusys_pll_apupll2", 0x038, 0x044, 0,
> +               0, 0, 22, 0x03c, 24, 0, 0, 0, 0x03c, 0, 0, 0, 0),

The datasheet doesn't provide names for these clocks. The values here look
correct though.

> +};
> +
> +static int clk_mt8195_apusys_pll_probe(struct platform_device *pdev)
> +{
> +       struct clk_onecell_data *clk_data;
> +       struct device_node *node = pdev->dev.of_node;
> +
> +       clk_data = mtk_alloc_clk_data(CLK_APUSYS_PLL_NR_CLK);
> +       if (!clk_data)
> +               return -ENOMEM;
> +
> +       mtk_clk_register_plls(node, apusys_plls, ARRAY_SIZE(apusys_plls), clk_data);
> +
> +       return of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
> +}
> +
> +static const struct of_device_id of_match_clk_mt8195_apusys_pll[] = {
> +       { .compatible = "mediatek,mt8195-apusys_pll", },
> +       {}
> +};
> +
> +static struct platform_driver clk_mt8195_apusys_pll_drv = {
> +       .probe = clk_mt8195_apusys_pll_probe,
> +       .driver = {
> +               .name = "clk-mt8195-apusys_pll",
> +               .of_match_table = of_match_clk_mt8195_apusys_pll,
> +       },
> +};
> +

The general comments from the other patches apply as well


Regards
ChenYu


> +builtin_platform_driver(clk_mt8195_apusys_pll_drv);
> --
> 2.18.0
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