Re: [PATCH v6 6/7] phy: phy-mtk-dp: Add driver for DP phy

Hi Chunfeng,

Quoting Chunfeng Yun (2021-11-13 08:48:37)

On Wed, 2021-11-10 at 14:06 +0100, Guillaume Ranquet wrote:

...

From: Markus Schneider-Pargmann msp@baylibre.com

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@baylibre.com Signed-off-by: Guillaume Ranquet granquet@baylibre.com

---

MAINTAINERS | 1 + drivers/phy/mediatek/Kconfig | 8 ++ drivers/phy/mediatek/Makefile | 1 + drivers/phy/mediatek/phy-mtk-dp.c | 219 ++++++++++++++++++++++++++++++ 4 files changed, 229 insertions(+) create mode 100644 drivers/phy/mediatek/phy-mtk-dp.c

diff --git a/MAINTAINERS b/MAINTAINERS index 170bbbeefc3f4..f9a71b6d2a4a9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6367,6 +6367,7 @@ L: linux-mediatek@lists.infradead.org (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 55f8e6c048ab3..f7ec860590492 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 ace660fbed3a1..4ba1e06504346 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 0000000000000..4f8d26ec0346b --- /dev/null +++ b/drivers/phy/mediatek/phy-mtk-dp.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • Copyright (c) 2021 BayLibre
• • Author: Markus Schneider-Pargmann msp@baylibre.com
• */

+#include <linux/delay.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/regmap.h>

+#define PHY_OFFSET 0x1000

Why not provide register base address in DTS? I find that phy's platform device is registered by dp driver but the one automatically created when parse dts?

This phy driver has no dt binding whatsoever, as it shares basically the same hardware as the DP driver, so everything has to be either hardcoded or passed through from the DP driver.

...

+#define MTK_DP_PHY_DIG_PLL_CTL_1 (PHY_OFFSET + 0x014) +# define TPLL_SSC_EN BIT(3)

+#define MTK_DP_PHY_DIG_BIT_RATE (PHY_OFFSET + 0x03C) +# 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 + 0x038) +# 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 0x10 +# define XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT (0x14 << 8) +# define XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT (0x18 << 16) +# define XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT (0x20 << 24) +# define DRIVING_PARAM_3_DEFAULT (XTP_LN_TX_LCTXC0_SW0_P RE0_DEFAULT | \

•                                          XTP_LN_TX_LCTXC0_SW0_P
  

RE1_DEFAULT | \

•                                          XTP_LN_TX_LCTXC0_SW0_P
  

RE2_DEFAULT | \

•                                          XTP_LN_TX_LCTXC0_SW0_P
  

RE3_DEFAULT)

+#define MTK_DP_LANE0_DRIVING_PARAM_4 (PHY_OFFSET + 0x13C) +#define MTK_DP_LANE1_DRIVING_PARAM_4 (PHY_OFFSET + 0x23C) +#define MTK_DP_LANE2_DRIVING_PARAM_4 (PHY_OFFSET + 0x33C) +#define MTK_DP_LANE3_DRIVING_PARAM_4 (PHY_OFFSET + 0x43C) +# define XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT 0x18 +# define XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT (0x1e << 8) +# define XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT (0x24 << 16) +# define XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT (0x20 << 24) +# define DRIVING_PARAM_4_DEFAULT (XTP_LN_TX_LCTXC0_SW1_P RE0_DEFAULT | \

•                                          XTP_LN_TX_LCTXC0_SW1_P
  

RE1_DEFAULT | \

•                                          XTP_LN_TX_LCTXC0_SW1_P
  

RE2_DEFAULT | \

•                                          XTP_LN_TX_LCTXC0_SW2_P
  

RE0_DEFAULT)

+#define MTK_DP_LANE0_DRIVING_PARAM_5 (PHY_OFFSET + 0x140) +#define MTK_DP_LANE1_DRIVING_PARAM_5 (PHY_OFFSET + 0x240) +#define MTK_DP_LANE2_DRIVING_PARAM_5 (PHY_OFFSET + 0x340) +#define MTK_DP_LANE3_DRIVING_PARAM_5 (PHY_OFFSET + 0x440) +# define XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT 0x28 +# define XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT (0x30 << 8) +# define DRIVING_PARAM_5_DEFAULT (XTP_LN_TX_LCTXC0_SW2_P RE1_DEFAULT | \

•                                          XTP_LN_TX_LCTXC0_SW3_P
  

RE0_DEFAULT)

+#define MTK_DP_LANE0_DRIVING_PARAM_6 (PHY_OFFSET + 0x144) +#define MTK_DP_LANE1_DRIVING_PARAM_6 (PHY_OFFSET + 0x244) +#define MTK_DP_LANE2_DRIVING_PARAM_6 (PHY_OFFSET + 0x344) +#define MTK_DP_LANE3_DRIVING_PARAM_6 (PHY_OFFSET + 0x444) +# define XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT 0x00 +# define XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT (0x04 << 8) +# define XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT (0x08 << 16) +# define XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT (0x10 << 24) +# 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 MTK_DP_LANE0_DRIVING_PARAM_7 (PHY_OFFSET + 0x148) +#define MTK_DP_LANE1_DRIVING_PARAM_7 (PHY_OFFSET + 0x248) +#define MTK_DP_LANE2_DRIVING_PARAM_7 (PHY_OFFSET + 0x348) +#define MTK_DP_LANE3_DRIVING_PARAM_7 (PHY_OFFSET + 0x448) +# define XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT 0x00 +# define XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT (0x06 << 8) +# define XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT (0x0c << 16) +# define XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT (0x00 << 24) +# 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 MTK_DP_LANE0_DRIVING_PARAM_8 (PHY_OFFSET + 0x14C) +#define MTK_DP_LANE1_DRIVING_PARAM_8 (PHY_OFFSET + 0x24C) +#define MTK_DP_LANE2_DRIVING_PARAM_8 (PHY_OFFSET + 0x34C) +#define MTK_DP_LANE3_DRIVING_PARAM_8 (PHY_OFFSET + 0x44C) +# define XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT 0x08 +# define XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT (0x00 << 8) +# 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;
  

• dp_phy = devm_kzalloc(dev, sizeof(*dp_phy), GFP_KERNEL);
  

• if (!dp_phy)
  

•         return -ENOMEM;
  

• dp_phy->regs = *(struct regmap **)dev->platform_data;
  

• if (!dp_phy->regs) {
  

•         dev_err(dev, "No data passed, requires struct
  

regmap**\n");

•         return -EINVAL;
  

• }
  

Why not get it from dts?

No dt bindings, this is passed from the dp driver (which triggers the probe of the phy btw).

...

• phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);
  

• if (IS_ERR(phy)) {
  

•         dev_err(dev, "Failed to create DP PHY: %ld\n",
  

PTR_ERR(phy));

•         return PTR_ERR(phy);
  

• }
  

• phy_set_drvdata(phy, dp_phy);
  

• // Set device data to the phy so that mtk-dp can get it easily
  

use /* */

...

• dev_set_drvdata(dev, phy);
  

• 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@baylibre.com"); +MODULE_DESCRIPTION("MediaTek DP PHY Driver"); +MODULE_LICENSE("GPL v2");