Re: [PATCH v11 1/1] phy: phy-mtk-dp: Add driver for DP phy

From: Vinod Koul
Date: Thu Jun 16 2022 - 20:47:43 EST


On 13-06-22, 15:26, Bo-Chen Chen wrote:
> From: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx>
>
> This is a new driver that supports the integrated DisplayPort phy for
> mediatek SoCs, especially the mt8195. The phy is integrated into the
> DisplayPort controller and will be created by the mtk-dp driver. This
> driver expects a struct regmap to be able to work on the same registers
> as the DisplayPort controller. It sets the device data to be the struct
> phy so that the DisplayPort controller can easily work with it.
>
> The driver does not have any devicetree bindings because the datasheet
> does not list the controller and the phy as distinct units.
>
> The interaction with the controller can be covered by the configure
> callback of the phy framework and its displayport parameters.
>
> Signed-off-by: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx>
> Signed-off-by: Guillaume Ranquet <granquet@xxxxxxxxxxxx>
> [Bo-Chen: Modify reviewers' comments.]
> Signed-off-by: Bo-Chen Chen <rex-bc.chen@xxxxxxxxxxxx>
> ---
> MAINTAINERS | 1 +
> drivers/phy/mediatek/Kconfig | 8 ++
> drivers/phy/mediatek/Makefile | 1 +
> drivers/phy/mediatek/phy-mtk-dp.c | 202 ++++++++++++++++++++++++++++++
> 4 files changed, 212 insertions(+)
> create mode 100644 drivers/phy/mediatek/phy-mtk-dp.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index a6d3bd9d2a8d..f1460ee9ce83 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6698,6 +6698,7 @@ L: linux-mediatek@xxxxxxxxxxxxxxxxxxx (moderated for non-subscribers)
> S: Supported
> F: Documentation/devicetree/bindings/display/mediatek/
> F: drivers/gpu/drm/mediatek/
> +F: drivers/phy/mediatek/phy-mtk-dp.c
> F: drivers/phy/mediatek/phy-mtk-hdmi*
> F: drivers/phy/mediatek/phy-mtk-mipi*
>
> diff --git a/drivers/phy/mediatek/Kconfig b/drivers/phy/mediatek/Kconfig
> index 55f8e6c048ab..d631525d12e1 100644
> --- a/drivers/phy/mediatek/Kconfig
> +++ b/drivers/phy/mediatek/Kconfig
> @@ -55,3 +55,11 @@ config PHY_MTK_MIPI_DSI
> select GENERIC_PHY
> help
> Support MIPI DSI for Mediatek SoCs.
> +
> +config PHY_MTK_DP
> + tristate "MediaTek DP-PHY Driver"
> + depends on ARCH_MEDIATEK || COMPILE_TEST
> + depends on OF
> + select GENERIC_PHY
> + help
> + Support DisplayPort PHY for MediaTek SoCs.
> diff --git a/drivers/phy/mediatek/Makefile b/drivers/phy/mediatek/Makefile
> index ace660fbed3a..4ba1e0650434 100644
> --- a/drivers/phy/mediatek/Makefile
> +++ b/drivers/phy/mediatek/Makefile
> @@ -3,6 +3,7 @@
> # Makefile for the phy drivers.
> #
>
> +obj-$(CONFIG_PHY_MTK_DP) += phy-mtk-dp.o
> obj-$(CONFIG_PHY_MTK_TPHY) += phy-mtk-tphy.o
> obj-$(CONFIG_PHY_MTK_UFS) += phy-mtk-ufs.o
> obj-$(CONFIG_PHY_MTK_XSPHY) += phy-mtk-xsphy.o
> diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
> new file mode 100644
> index 000000000000..c4d5ca1719a4
> --- /dev/null
> +++ b/drivers/phy/mediatek/phy-mtk-dp.c
> @@ -0,0 +1,202 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * MediaTek DisplayPort PHY driver
> + *
> + * Copyright (c) 2022 BayLibre
> + * Copyright (c) 2022 MediaTek

It should be proper name of companies (hint see other uses)

> + */
> +
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +#define PHY_OFFSET 0x1000
> +
> +#define MTK_DP_PHY_DIG_PLL_CTL_1 (PHY_OFFSET + 0x14)
> +#define TPLL_SSC_EN BIT(3)
> +
> +#define MTK_DP_PHY_DIG_BIT_RATE (PHY_OFFSET + 0x3C)
> +#define BIT_RATE_RBR 0
> +#define BIT_RATE_HBR 1
> +#define BIT_RATE_HBR2 2
> +#define BIT_RATE_HBR3 3
> +
> +#define MTK_DP_PHY_DIG_SW_RST (PHY_OFFSET + 0x38)
> +#define DP_GLB_SW_RST_PHYD BIT(0)
> +
> +#define MTK_DP_LANE0_DRIVING_PARAM_3 (PHY_OFFSET + 0x138)
> +#define MTK_DP_LANE1_DRIVING_PARAM_3 (PHY_OFFSET + 0x238)
> +#define MTK_DP_LANE2_DRIVING_PARAM_3 (PHY_OFFSET + 0x338)
> +#define MTK_DP_LANE3_DRIVING_PARAM_3 (PHY_OFFSET + 0x438)
> +#define XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT BIT(4)
> +#define XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT (BIT(10) | BIT(12))
> +#define XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT GENMASK(20, 19)
> +#define XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT GENMASK(29, 29)
> +#define DRIVING_PARAM_3_DEFAULT (XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT | \
> + XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT | \
> + XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT | \
> + XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT)
> +
> +#define XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT GENMASK(4, 3)
> +#define XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT GENMASK(12, 9)
> +#define XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT (BIT(18) | BIT(21))
> +#define XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT GENMASK(29, 29)
> +#define DRIVING_PARAM_4_DEFAULT (XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT | \
> + XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT | \
> + XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT | \
> + XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT)
> +
> +#define XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT (BIT(3) | BIT(5))
> +#define XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT GENMASK(13, 12)
> +#define DRIVING_PARAM_5_DEFAULT (XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT | \
> + XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT)
> +
> +#define XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT 0
> +#define XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT GENMASK(10, 10)
> +#define XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT GENMASK(19, 19)
> +#define XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT GENMASK(28, 28)
> +#define DRIVING_PARAM_6_DEFAULT (XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT | \
> + XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT | \
> + XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT | \
> + XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT)
> +
> +#define XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT 0
> +#define XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT GENMASK(10, 9)
> +#define XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT GENMASK(19, 18)
> +#define XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT 0
> +#define DRIVING_PARAM_7_DEFAULT (XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT | \
> + XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT | \
> + XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT | \
> + XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT)
> +
> +#define XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT GENMASK(3, 3)
> +#define XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT 0
> +#define DRIVING_PARAM_8_DEFAULT (XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT | \
> + XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
> +
> +struct mtk_dp_phy {
> + struct regmap *regs;
> +};
> +
> +static int mtk_dp_phy_init(struct phy *phy)
> +{
> + struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
> + u32 driving_params[] = {
> + DRIVING_PARAM_3_DEFAULT,
> + DRIVING_PARAM_4_DEFAULT,
> + DRIVING_PARAM_5_DEFAULT,
> + DRIVING_PARAM_6_DEFAULT,
> + DRIVING_PARAM_7_DEFAULT,
> + DRIVING_PARAM_8_DEFAULT
> + };
> +
> + regmap_bulk_write(dp_phy->regs, MTK_DP_LANE0_DRIVING_PARAM_3,
> + driving_params, ARRAY_SIZE(driving_params));
> + regmap_bulk_write(dp_phy->regs, MTK_DP_LANE1_DRIVING_PARAM_3,
> + driving_params, ARRAY_SIZE(driving_params));
> + regmap_bulk_write(dp_phy->regs, MTK_DP_LANE2_DRIVING_PARAM_3,
> + driving_params, ARRAY_SIZE(driving_params));
> + regmap_bulk_write(dp_phy->regs, MTK_DP_LANE3_DRIVING_PARAM_3,
> + driving_params, ARRAY_SIZE(driving_params));
> +
> + return 0;
> +}
> +
> +static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
> +{
> + struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
> + u32 val;
> +
> + if (opts->dp.set_rate) {
> + switch (opts->dp.link_rate) {
> + default:
> + dev_err(&phy->dev,
> + "Implementation error, unknown linkrate %x\n",
> + opts->dp.link_rate);
> + return -EINVAL;
> + case 1620:
> + val = BIT_RATE_RBR;
> + break;
> + case 2700:
> + val = BIT_RATE_HBR;
> + break;
> + case 5400:
> + val = BIT_RATE_HBR2;
> + break;
> + case 8100:
> + val = BIT_RATE_HBR3;
> + break;
> + }
> + regmap_write(dp_phy->regs, MTK_DP_PHY_DIG_BIT_RATE, val);
> + }
> +
> + regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_PLL_CTL_1,
> + TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0);
> +
> + return 0;
> +}
> +
> +static int mtk_dp_phy_reset(struct phy *phy)
> +{
> + struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
> +
> + regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_SW_RST,
> + DP_GLB_SW_RST_PHYD, 0);
> + usleep_range(50, 200);
> + regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_SW_RST,
> + DP_GLB_SW_RST_PHYD, 1);
> +
> + return 0;
> +}
> +
> +static const struct phy_ops mtk_dp_phy_dev_ops = {
> + .init = mtk_dp_phy_init,
> + .configure = mtk_dp_phy_configure,
> + .reset = mtk_dp_phy_reset,
> + .owner = THIS_MODULE,
> +};
> +
> +static int mtk_dp_phy_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct mtk_dp_phy *dp_phy;
> + struct phy *phy;
> + struct regmap *regs;
> +
> + regs = *(struct regmap **)dev->platform_data;

why do you need this cast away from void?

> + if (!regs)
> + return dev_err_probe(dev, EINVAL,
> + "No data passed, requires struct regmap**\n");
> +
> + dp_phy = devm_kzalloc(dev, sizeof(*dp_phy), GFP_KERNEL);
> + if (!dp_phy)
> + return -ENOMEM;
> +
> + dp_phy->regs = regs;
> + phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);
> + if (IS_ERR(phy))
> + return dev_err_probe(dev, PTR_ERR(phy),
> + "Failed to create DP PHY\n");
> +
> + phy_set_drvdata(phy, dp_phy);
> + if (!dev->of_node)
> + phy_create_lookup(phy, "dp", dev_name(dev));
> +
> + return 0;
> +}
> +
> +struct platform_driver mtk_dp_phy_driver = {
> + .probe = mtk_dp_phy_probe,
> + .driver = {
> + .name = "mediatek-dp-phy",
> + },
> +};
> +module_platform_driver(mtk_dp_phy_driver);
> +
> +MODULE_AUTHOR("Markus Schneider-Pargmann <msp@xxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("MediaTek DP PHY Driver");
> +MODULE_LICENSE("GPL");
> --
> 2.18.0

--
~Vinod