Re: [PATCH 17/22] clk: mediatek: Add MT8195 vencsys clock support

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

On Thu, Jun 17, 2021 at 7:10 AM Chun-Jie Chen
<chun-jie.chen@mediatek.com> wrote:
>
> Add MT8195 vencsys clock providers
>
> 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-venc.c | 71 ++++++++++++++++++++++++++
>  3 files changed, 78 insertions(+)
>  create mode 100644 drivers/clk/mediatek/clk-mt8195-venc.c
>
> diff --git a/drivers/clk/mediatek/Kconfig b/drivers/clk/mediatek/Kconfig
> index 1e89c68f6c6c..3352686d98cf 100644
> --- a/drivers/clk/mediatek/Kconfig
> +++ b/drivers/clk/mediatek/Kconfig
> @@ -660,6 +660,12 @@ config COMMON_CLK_MT8195_VDOSYS1
>         help
>           This driver supports MediaTek MT8195 vdosys1 clocks.
>
> +config COMMON_CLK_MT8195_VENCSYS
> +       bool "Clock driver for MediaTek MT8195 vencsys"
> +       depends on COMMON_CLK_MT8195
> +       help
> +         This driver supports MediaTek MT8195 vencsys 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 76c0fa837cb0..76a6b404e34b 100644
> --- a/drivers/clk/mediatek/Makefile
> +++ b/drivers/clk/mediatek/Makefile
> @@ -93,5 +93,6 @@ obj-$(CONFIG_COMMON_CLK_MT8195_NNASYS) += clk-mt8195-nna.o
>  obj-$(CONFIG_COMMON_CLK_MT8195_VDECSYS) += clk-mt8195-vdec.o
>  obj-$(CONFIG_COMMON_CLK_MT8195_VDOSYS0) += clk-mt8195-vdo0.o
>  obj-$(CONFIG_COMMON_CLK_MT8195_VDOSYS1) += clk-mt8195-vdo1.o
> +obj-$(CONFIG_COMMON_CLK_MT8195_VENCSYS) += clk-mt8195-venc.o
>  obj-$(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-venc.c b/drivers/clk/mediatek/clk-mt8195-venc.c
> new file mode 100644
> index 000000000000..410ca69d5759
> --- /dev/null
> +++ b/drivers/clk/mediatek/clk-mt8195-venc.c
> @@ -0,0 +1,71 @@
> +// 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>
> +
> +static const struct mtk_gate_regs venc_cg_regs = {
> +       .set_ofs = 0x4,
> +       .clr_ofs = 0x8,
> +       .sta_ofs = 0x0,
> +};
> +
> +#define GATE_VENC(_id, _name, _parent, _shift)                 \
> +       GATE_MTK(_id, _name, _parent, &venc_cg_regs, _shift, &mtk_clk_gate_ops_setclr_inv)
> +
> +static const struct mtk_gate venc_clks[] = {
> +       GATE_VENC(CLK_VENC_LARB, "venc_larb", "venc_sel", 0),
> +       GATE_VENC(CLK_VENC_VENC, "venc_venc", "venc_sel", 4),
> +       GATE_VENC(CLK_VENC_JPGENC, "venc_jpgenc", "venc_sel", 8),
> +       GATE_VENC(CLK_VENC_JPGDEC, "venc_jpgdec", "venc_sel", 12),
> +       GATE_VENC(CLK_VENC_JPGDEC_C1, "venc_jpgdec_c1", "venc_sel", 16),
> +       GATE_VENC(CLK_VENC_GALS, "venc_gals", "venc_sel", 28),
> +};
> +
> +static const struct mtk_gate venc_core1_clks[] = {
> +       GATE_VENC(CLK_VENC_CORE1_LARB, "venc_core1_larb", "venc_sel", 0),
> +       GATE_VENC(CLK_VENC_CORE1_VENC, "venc_core1_venc", "venc_sel", 4),
> +       GATE_VENC(CLK_VENC_CORE1_JPGENC, "venc_core1_jpgenc", "venc_sel", 8),
> +       GATE_VENC(CLK_VENC_CORE1_JPGDEC, "venc_core1_jpgdec", "venc_sel", 12),
> +       GATE_VENC(CLK_VENC_CORE1_JPGDEC_C1, "venc_core1_jpgdec_c1", "venc_sel", 16),
> +       GATE_VENC(CLK_VENC_CORE1_GALS, "venc_core1_gals", "venc_sel", 28),
> +};

So I'm not sure why there are two sets of clocks for each endpoint.
Since this hardware block is not documented in the datasheet, maybe
you could provide some explanation? What I'm wondering is if the
first set is actually some clock gate for bus access and the second
set is the main module clock that drives the internal logic.

The general comments from the other patches apply as well.


ChenYu

> +
> +static const struct mtk_clk_desc venc_desc = {
> +       .clks = venc_clks,
> +       .num_clks = ARRAY_SIZE(venc_clks),
> +};
> +
> +static const struct mtk_clk_desc venc_core1_desc = {
> +       .clks = venc_core1_clks,
> +       .num_clks = ARRAY_SIZE(venc_core1_clks),
> +};
> +
> +static const struct of_device_id of_match_clk_mt8195_venc[] = {
> +       {
> +               .compatible = "mediatek,mt8195-vencsys",
> +               .data = &venc_desc,
> +       }, {
> +               .compatible = "mediatek,mt8195-vencsys_core1",
> +               .data = &venc_core1_desc,
> +       }, {
> +               /* sentinel */
> +       }
> +};
> +
> +static struct platform_driver clk_mt8195_venc_drv = {
> +       .probe = mtk_clk_simple_probe,
> +       .driver = {
> +               .name = "clk-mt8195-venc",
> +               .of_match_table = of_match_clk_mt8195_venc,
> +       },
> +};
> +
> +builtin_platform_driver(clk_mt8195_venc_drv);
> --
> 2.18.0
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