Re: [PATCH v2 02/15] clk: mediatek: Add MT8186 mcusys clock support

Chen-Yu Tsai
2022-03-09T10:14:16Z

Hi,

On Mon, Feb 21, 2022 at 9:59 AM Chun-Jie Chen
<chun-jie.chen@mediatek.com> wrote:
>
> Add MT8186 mcusys clock controller which provides muxes
> to select the clock source of APMCU.
>
> Signed-off-by: Chun-Jie Chen <chun-jie.chen@mediatek.com>
> Acked-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
> drivers/clk/mediatek/Kconfig | 8 ++
> drivers/clk/mediatek/Makefile | 1 +
> drivers/clk/mediatek/clk-mt8186-mcu.c | 106 ++++++++++++++++++++++++++
> 3 files changed, 115 insertions(+)
> create mode 100644 drivers/clk/mediatek/clk-mt8186-mcu.c
>
> diff --git a/drivers/clk/mediatek/Kconfig b/drivers/clk/mediatek/Kconfig
> index 01ef02c54725..d5936cfb3bee 100644
> --- a/drivers/clk/mediatek/Kconfig
> +++ b/drivers/clk/mediatek/Kconfig
> @@ -512,6 +512,14 @@ config COMMON_CLK_MT8183_VENCSYS
> help
> This driver supports MediaTek MT8183 vencsys clocks.
>
> +config COMMON_CLK_MT8186
> + bool "Clock driver for MediaTek MT8186"
> + depends on ARM64 || COMPILE_TEST
> + select COMMON_CLK_MEDIATEK
> + default ARCH_MEDIATEK
> + help
> + This driver supports MediaTek MT8186 clocks.
> +
> config COMMON_CLK_MT8192
> bool "Clock driver for MediaTek MT8192"
> depends on ARM64 || COMPILE_TEST
> diff --git a/drivers/clk/mediatek/Makefile b/drivers/clk/mediatek/Makefile
> index 7b0c2646ce4a..677fa4f0eea2 100644
> --- a/drivers/clk/mediatek/Makefile
> +++ b/drivers/clk/mediatek/Makefile
> @@ -71,6 +71,7 @@ obj-$(CONFIG_COMMON_CLK_MT8183_MFGCFG) += clk-mt8183-mfgcfg.o
> obj-$(CONFIG_COMMON_CLK_MT8183_MMSYS) += clk-mt8183-mm.o
> obj-$(CONFIG_COMMON_CLK_MT8183_VDECSYS) += clk-mt8183-vdec.o
> obj-$(CONFIG_COMMON_CLK_MT8183_VENCSYS) += clk-mt8183-venc.o
> +obj-$(CONFIG_COMMON_CLK_MT8186) += clk-mt8186-mcu.o
> obj-$(CONFIG_COMMON_CLK_MT8192) += clk-mt8192.o
> obj-$(CONFIG_COMMON_CLK_MT8192_AUDSYS) += clk-mt8192-aud.o
> obj-$(CONFIG_COMMON_CLK_MT8192_CAMSYS) += clk-mt8192-cam.o
> diff --git a/drivers/clk/mediatek/clk-mt8186-mcu.c b/drivers/clk/mediatek/clk-mt8186-mcu.c
> new file mode 100644
> index 000000000000..6d82c5de16c1
> --- /dev/null
> +++ b/drivers/clk/mediatek/clk-mt8186-mcu.c
> @@ -0,0 +1,106 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +//
> +// Copyright (c) 2022 MediaTek Inc.
> +// Author: Chun-Jie Chen <chun-jie.chen@mediatek.com>
> +
> +#include "clk-mtk.h"

Please move local headers after global ones. And please do this for all
patches.

> +
> +#include <dt-bindings/clock/mt8186-clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/platform_device.h>
> +
> +static DEFINE_SPINLOCK(mt8186_clk_lock);
> +
> +static const char * const mcu_armpll_ll_parents[] = {
> + "clk26m",
> + "armpll_ll",
> + "mainpll",
> + "univpll_d2"
> +};
> +
> +static const char * const mcu_armpll_bl_parents[] = {
> + "clk26m",
> + "armpll_bl",
> + "mainpll",
> + "univpll_d2"
> +};
> +
> +static const char * const mcu_armpll_bus_parents[] = {
> + "clk26m",
> + "ccipll",
> + "mainpll",
> + "univpll_d2"
> +};
> +
> +static struct mtk_composite mcu_muxes[] = {
> + /* CPU_PLLDIV_CFG0 */
> + MUX(CLK_MCU_ARMPLL_LL_SEL, "mcu_armpll_ll_sel", mcu_armpll_ll_parents, 0x2A0, 9, 2),

Can you add a comment stating that these registers have other bits that
should not be touched? Otherwise anyone reading the datasheet might
consider this to be incomplete.

I assume the other bits (such as one field that looks like a divider) are
configured in the bootloader, or the POR defaults are correct.

> + /* CPU_PLLDIV_CFG1 */
> + MUX(CLK_MCU_ARMPLL_BL_SEL, "mcu_armpll_bl_sel", mcu_armpll_bl_parents, 0x2A4, 9, 2),
> + /* BUS_PLLDIV_CFG */
> + MUX(CLK_MCU_ARMPLL_BUS_SEL, "mcu_armpll_bus_sel", mcu_armpll_bus_parents, 0x2E0, 9, 2),
> +};

Note: I've checked the register bits against the datasheet.

> +
> +static const struct of_device_id of_match_clk_mt8186_mcu[] = {
> + { .compatible = "mediatek,mt8186-mcusys", },
> + {}
> +};
> +
> +static int clk_mt8186_mcu_probe(struct platform_device *pdev)
> +{
> + struct clk_onecell_data *clk_data;
> + struct device_node *node = pdev->dev.of_node;
> + int r;
> + void __iomem *base;
> +
> + clk_data = mtk_alloc_clk_data(CLK_MCU_NR_CLK);
> + if (!clk_data)
> + return -ENOMEM;
> +
> + base = devm_platform_ioremap_resource(pdev, 0);
> + if (IS_ERR(base)) {
> + r = PTR_ERR(base);
> + goto free_mcu_data;
> + }
> +
> + r = mtk_clk_register_composites(mcu_muxes, ARRAY_SIZE(mcu_muxes), base,
> + &mt8186_clk_lock, clk_data);

I don't think you need the lock. None of the bit fields you have defined
in this driver have overlapping registers.

Regards
ChenYu

> + if (r)
> + goto free_mcu_data;
> +
> + r = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
> + if (r)
> + goto unregister_composite_muxes;
> +
> + platform_set_drvdata(pdev, clk_data);
> +
> + return r;
> +
> +unregister_composite_muxes:
> + mtk_clk_unregister_composites(mcu_muxes, ARRAY_SIZE(mcu_muxes), clk_data);
> +free_mcu_data:
> + mtk_free_clk_data(clk_data);
> + return r;
> +}
> +
> +static int clk_mt8186_mcu_remove(struct platform_device *pdev)
> +{
> + struct clk_onecell_data *clk_data = platform_get_drvdata(pdev);
> + struct device_node *node = pdev->dev.of_node;
> +
> + of_clk_del_provider(node);
> + mtk_clk_unregister_composites(mcu_muxes, ARRAY_SIZE(mcu_muxes), clk_data);
> + mtk_free_clk_data(clk_data);
> +
> + return 0;
> +}
> +
> +static struct platform_driver clk_mt8186_mcu_drv = {
> + .probe = clk_mt8186_mcu_probe,
> + .remove = clk_mt8186_mcu_remove,
> + .driver = {
> + .name = "clk-mt8186-mcu",
> + .of_match_table = of_match_clk_mt8186_mcu,
> + },
> +};
> +builtin_platform_driver(clk_mt8186_mcu_drv);
> --
> 2.18.0
>