[PATCH v4 00/12] PHY: MediaTek DP PHY refactor and MT8196 eDP

[PATCH v4 00/12] PHY: MediaTek DP PHY refactor and MT8196 eDP

[AngeloGioacchino Del Regno]

Changes in v4:
 - Removed error checking from all regmap_(bulk_){read,write} calls
   as those are on MMIO and can't fail (Mani)
 - Changed some of the error prints in mtk_dp_phy_get_one_cal_para()
   to dev_err_probe() (Mani, Sashiko)

Changes in v3:
 - Added missing bitfield.h, pm_runtime.h includes (Sashiko)
 - Set calibration data before registering PHY (Sashiko)
 - Enable PM Runtime before creating PHY device (Sashiko)
 - Continue poweroff if some write fails, but still return failure
   as that would be a partial poweroff anyway (Sashiko)
 - Added zero driving params to fix default calibration data setting (Sashiko)
 - Added NULL check on device_Get_match_data (Sashiko)

Changes in v2:
 - Fixed register offsets for ANA phy in MT8196
 - Set/clear FORCE_VOLT_SWING_EN bit when configuring and resetting
   the voltage swing registers
 - Fixed endianness issue in call to nvmem_read_u16 (Sashiko)
 - Added early exit during lanes disablement if none are enabled to
   avoid out-of-bounds bitwise shift (Sashiko)
 - Removed useless call to pm_runtime_get_sync() in probe(), which
   also fixes issues pointed out by Sashiko
 - Fixed wrong dig vs ana register array usage in power_on/off (Sashiko)


This series performs major refactoring on the MediaTek DisplayPort PHY
driver, makes it probe with devicetree instead of getting registered
by the mtk_dp DRM driver, adds power_on/off() callbacks, and honors
the phy configure opts' set_lanes and set_voltages for, respectively,
varying the number of lanes and setting the voltage pre-emphasis and
swing on the PHY, for each lane.

This driver now also properly gets the PHY (EYE) Calibration Data from
NVMEM (eFuse array) if provided, instead of getting it (improperly)
injected by the mtk_dp driver.

Additionally, all of the driving parameters calculations and most of
the other register definitions were refactored to greatly enhance the
human readability of this code.

As a last step, this also transfers the register offsets for both the
digital and analog phy registers in arrays assigned to soc specific
data, in an effort to both introduce support for new minor revisions
of the MediaTek DisplayPort PHY and to have a clearer view of the
register related differences between those (for example, it is easily
understandable that the analog part remained exactly the same between
MT8195 and MT8196, but the digital part gets a slight update).

Speaking of which, as a last step, this also adds support for the
MT8196 SoC (and its derivatives), which uses this PHY only for its
Embedded DisplayPort (eDP) IP (spoiler: the DP one seems to be way
too different and requiring an entirely new PHY driver).

In this state, this driver can also easily support the MT8189 SoC
with a few lines of code: even though I do have clean code to add
support for this one, I was not (*yet*) able to test it on upstream
based kernels, and for this reason I decided to leave that one out
for now (but it's coming later for sure).

NOTE!
Despite all the apparently breaking changes in the refactoring, full
compatibility with older MTK_DP driver and with old devicetrees was
retained and carefully tested on multiple platforms!

P.S.: I am aware of the BUILD_DRIVING_PARAM_0( 0, 2, 4, 7) checkpatch
warning and I didn't fix it in bigger favor of human readability.

AngeloGioacchino Del Regno (12):
  dt-bindings: phy: Document MT8195 and MT8196 DisplayPort PHYs
  phy: phy-mtk-dp: Rename regs to regmap in struct mtk_dp_phy
  phy: phy-mtk-dp: Allow probing with devicetree match
  phy: phy-mtk-dp: Migrate register offsets to SoC specific pdata
  phy: phy-mtk-dp: Implement power_on and power_off PHY callbacks
  phy: phy-mtk-dp: Support set_lanes in configure and properly cleanup
  phy: phy-mtk-dp: Support setting volt swing and preemphasis values
  phy: phy-mtk-dp: Add support for digital and analog calibration
  phy: phy-mtk-dp: Rewrite and document default driving param macros
  phy: phy-mtk-dp: Add bitrate register val definitions to SoC data
  phy: phy-mtk-dp: Add PHYD Lane EN register mask to SoC data
  phy: phy-mtk-dp: Add support for MT8196 eDP PHY

 .../bindings/phy/mediatek,mt8195-dp-phy.yaml  |  77 ++
 drivers/phy/mediatek/phy-mtk-dp.c             | 832 ++++++++++++++++--
 2 files changed, 812 insertions(+), 97 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/phy/mediatek,mt8195-dp-phy.yaml

-- 
2.55.0

[PATCH v4 01/12] dt-bindings: phy: Document MT8195 and MT8196 DisplayPort PHYs

[AngeloGioacchino Del Regno]

This adds bindings for the DisplayPort and Embedded DisplayPort
PHYs found in the MediaTek MT8195 SoC (and variants of) and for
the Embedded DisplayPort found in the MT8196 SoC (and variants).

This PHY supports varying impedance calibrations for the various
signals to reach an optimal EYE signal pattern for any specific
board(s), especially useful for very high bitrates such as HBR3
and higher, depending on board design.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 .../bindings/phy/mediatek,mt8195-dp-phy.yaml  | 77 +++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/mediatek,mt8195-dp-phy.yaml

diff --git a/Documentation/devicetree/bindings/phy/mediatek,mt8195-dp-phy.yaml b/Documentation/devicetree/bindings/phy/mediatek,mt8195-dp-phy.yaml
new file mode 100644
index 000000000000..1c2dc4f03cd6
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/mediatek,mt8195-dp-phy.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/mediatek,mt8195-dp-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek SoC DisplayPort Transmitter PHY
+
+maintainers:
+  - AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
+
+properties:
+  compatible:
+    enum:
+      - mediatek,mt8195-dp-phy
+      - mediatek,mt8196-edp-phy
+
+  reg:
+    maxItems: 1
+
+  "#phy-cells":
+    const: 0
+
+  nvmem-cells:
+    description: PHY calibrations from eFuse for optimal EYE signal pattern
+    items:
+      - description: PHY-Global Reference Bias trim
+      - description: PHY-Global AUX Transmitter clock impedance adjustment
+      - description: Lane 0 Transmitter impedance selection (P-MOSFET)
+      - description: Lane 0 Transmitter impedance selection (N-MOSFET)
+      - description: Lane 1 Transmitter impedance selection (P-MOSFET)
+      - description: Lane 1 Transmitter impedance selection (N-MOSFET)
+      - description: Lane 2 Transmitter impedance selection (P-MOSFET)
+      - description: Lane 2 Transmitter impedance selection (N-MOSFET)
+      - description: Lane 3 Transmitter impedance selection (P-MOSFET)
+      - description: Lane 3 Transmitter impedance selection (N-MOSFET)
+
+  nvmem-cell-names:
+    items:
+      - const: rbias-trim
+      - const: impedance-txclk
+      - const: impedance-lane0p
+      - const: impedance-lane0n
+      - const: impedance-lane1p
+      - const: impedance-lane1n
+      - const: impedance-lane2p
+      - const: impedance-lane2n
+      - const: impedance-lane3p
+      - const: impedance-lane3n
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    phy@1c500000 {
+        compatible = "mediatek,mt8195-dp-phy";
+        reg = <0x1c500000 0x2000>;
+        #phy-cells = <0>;
+        nvmem-cells = <&edp_glb_bias_trim>, <&edp_clktx_impsel>,
+                      <&edp_imp_ln0_pmos>, <&edp_imp_ln0_nmos>,
+                      <&edp_imp_ln1_pmos>, <&edp_imp_ln1_nmos>,
+                      <&edp_imp_ln2_pmos>, <&edp_imp_ln2_nmos>,
+                      <&edp_imp_ln3_pmos>, <&edp_imp_ln3_nmos>;
+        nvmem-cell-names = "rbias-trim", "impedance-txclk",
+                           "impedance-lane0p", "impedance-lane0n",
+                           "impedance-lane1p", "impedance-lane1n",
+                           "impedance-lane2p", "impedance-lane2n",
+                           "impedance-lane3p", "impedance-lane3n";
+    };
-- 
2.55.0

Re: [PATCH v4 01/12] dt-bindings: phy: Document MT8195 and MT8196 DisplayPort PHYs

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The proposed PHY binding models the PHY as a standalone device with a `reg` region that overlaps the existing DP/eDP MAC controller, causing resource conflicts and breaking backward compatibility.
--

commit 4c8f0a6ba6ee74a2973e7591e070dd77de336be6
Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

dt-bindings: phy: Document MT8195 and MT8196 DisplayPort PHYs

This commit adds bindings for the DisplayPort and Embedded DisplayPort PHYs
found in the MediaTek MT8195 and MT8196 SoCs. The PHY supports varying
impedance calibrations to reach an optimal EYE signal pattern.

> diff --git a/Documentation/devicetree/bindings/phy/mediatek,mt8195-dp-phy.yaml b/Documentation/devicetree/bindings/phy/mediatek,mt8195-dp-phy.yaml
> new file mode 100644
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/mediatek,mt8195-dp-phy.yaml
> @@ -0,0 +1,77 @@
[ ... ]
> +properties:
> +  compatible:
> +    enum:
> +      - mediatek,mt8195-dp-phy
> +      - mediatek,mt8196-edp-phy
> +
> +  reg:
> +    maxItems: 1

[Severity: High]
Will this reg property overlap with the existing DP/eDP MAC controller?

If this new binding is implemented as a standalone device node, the PHY
driver (mtk_dp_phy_probe) and the DP driver (mtk_dp_dt_parse) will both
call devm_platform_ioremap_resource() on the same memory space.

Since the DP controller currently maps the entire 32KB region and the PHY
binding requires mapping the first 8KB, will they conflict when requesting
the memory region from iomem_resource?

It appears the second driver to probe would fail with -EBUSY, breaking
backward compatibility for display functionality.

[ ... ]
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    phy@1c500000 {
> +        compatible = "mediatek,mt8195-dp-phy";
> +        reg = <0x1c500000 0x2000>;

[Severity: High]
Does this example demonstrate mapping the PHY exactly where the existing
mediatek,mt8195-edp-tx device is mapped in older device trees?

If the device tree uses this newly documented PHY node layout, it seems a
regression would occur unconditionally during system boot due to the
conflicting memory regions.

> +        #phy-cells = <0>;
[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910092038.48291-1-angelogioacchino.delregno@collabora.com?part=1

[PATCH v4 02/12] phy: phy-mtk-dp: Rename regs to regmap in struct mtk_dp_phy

[AngeloGioacchino Del Regno]

In preparation to perform further cleanups and to extend the
driver to support more SoCs, rename the `regs` member to `regmap`
to improve readability, as this is a common name across many
kernel drivers for a struct regmap.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index d7024a144335..bf7b3a95e72d 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -79,7 +79,7 @@
 				 XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
 
 struct mtk_dp_phy {
-	struct regmap *regs;
+	struct regmap *regmap;
 };
 
 static int mtk_dp_phy_init(struct phy *phy)
@@ -94,13 +94,13 @@ static int mtk_dp_phy_init(struct phy *phy)
 		DRIVING_PARAM_8_DEFAULT
 	};
 
-	regmap_bulk_write(dp_phy->regs, MTK_DP_LANE0_DRIVING_PARAM_3,
+	regmap_bulk_write(dp_phy->regmap, MTK_DP_LANE0_DRIVING_PARAM_3,
 			  driving_params, ARRAY_SIZE(driving_params));
-	regmap_bulk_write(dp_phy->regs, MTK_DP_LANE1_DRIVING_PARAM_3,
+	regmap_bulk_write(dp_phy->regmap, MTK_DP_LANE1_DRIVING_PARAM_3,
 			  driving_params, ARRAY_SIZE(driving_params));
-	regmap_bulk_write(dp_phy->regs, MTK_DP_LANE2_DRIVING_PARAM_3,
+	regmap_bulk_write(dp_phy->regmap, MTK_DP_LANE2_DRIVING_PARAM_3,
 			  driving_params, ARRAY_SIZE(driving_params));
-	regmap_bulk_write(dp_phy->regs, MTK_DP_LANE3_DRIVING_PARAM_3,
+	regmap_bulk_write(dp_phy->regmap, MTK_DP_LANE3_DRIVING_PARAM_3,
 			  driving_params, ARRAY_SIZE(driving_params));
 
 	return 0;
@@ -131,10 +131,10 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 			val = BIT_RATE_HBR3;
 			break;
 		}
-		regmap_write(dp_phy->regs, MTK_DP_PHY_DIG_BIT_RATE, val);
+		regmap_write(dp_phy->regmap, MTK_DP_PHY_DIG_BIT_RATE, val);
 	}
 
-	regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_PLL_CTL_1,
+	regmap_update_bits(dp_phy->regmap, MTK_DP_PHY_DIG_PLL_CTL_1,
 			   TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0);
 
 	return 0;
@@ -144,10 +144,10 @@ 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,
+	regmap_update_bits(dp_phy->regmap, 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,
+	regmap_update_bits(dp_phy->regmap, MTK_DP_PHY_DIG_SW_RST,
 			   DP_GLB_SW_RST_PHYD, 1);
 
 	return 0;
@@ -176,7 +176,7 @@ static int mtk_dp_phy_probe(struct platform_device *pdev)
 	if (!dp_phy)
 		return -ENOMEM;
 
-	dp_phy->regs = regs;
+	dp_phy->regmap = regs;
 	phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);
 	if (IS_ERR(phy))
 		return dev_err_probe(dev, PTR_ERR(phy),
-- 
2.55.0

[PATCH v4 03/12] phy: phy-mtk-dp: Allow probing with devicetree match

[AngeloGioacchino Del Regno]

Make it possible to decouple the registration of the DisplayPort
PHY driver from the DisplayPort IP driver by adding a devicetree
match to probe the PHY, registering an OF PHY provider and this
device's own MMIO regmap - if, and only if, this PHY driver was
registered with an OF match.

In order to retain compatibility with older devicetrees that are
not declaring the DisplayPort PHY as a separate node, the legacy
code was moved in a `mtk_dp_phy_legacy_probe()` function, which
gets called if the driver was registered by the DisplayPort one.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 88 +++++++++++++++++++++++++++----
 1 file changed, 78 insertions(+), 10 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index bf7b3a95e72d..d241004e2828 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -12,6 +12,7 @@
 #include <linux/of.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 
 #define PHY_OFFSET			0x1000
@@ -79,6 +80,7 @@
 				 XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
 
 struct mtk_dp_phy {
+	struct device *dev;
 	struct regmap *regmap;
 };
 
@@ -160,43 +162,109 @@ static const struct phy_ops mtk_dp_phy_dev_ops = {
 	.owner = THIS_MODULE,
 };
 
+static void mtk_dp_phy_legacy_remove_lookup(void *data)
+{
+	struct phy *phy = data;
+	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
+
+	phy_remove_lookup(phy, "dp", dev_name(dp_phy->dev));
+}
+
+static int mtk_dp_phy_legacy_probe(struct platform_device *pdev, struct mtk_dp_phy *dp_phy)
+{
+	struct device *dev = &pdev->dev;
+	struct phy *phy;
+	int ret;
+
+	dp_phy->regmap = *(struct regmap **)dev->platform_data;
+	if (!dp_phy->regmap)
+		return dev_err_probe(dev, -EINVAL, "No platform data available\n");
+
+	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);
+	ret = phy_create_lookup(phy, "dp", dev_name(dev));
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, mtk_dp_phy_legacy_remove_lookup, phy);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct regmap_config mtk_dp_phy_regmap_cfg = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.disable_locking = true,
+};
+
 static int mtk_dp_phy_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct phy_provider *provider;
 	struct mtk_dp_phy *dp_phy;
+	void __iomem *base;
 	struct phy *phy;
-	struct regmap *regs;
-
-	regs = *(struct regmap **)dev->platform_data;
-	if (!regs)
-		return dev_err_probe(dev, -EINVAL,
-				     "No data passed, requires struct regmap**\n");
+	int ret;
 
 	dp_phy = devm_kzalloc(dev, sizeof(*dp_phy), GFP_KERNEL);
 	if (!dp_phy)
 		return -ENOMEM;
 
-	dp_phy->regmap = regs;
+	dp_phy->dev = dev;
+
+	/* If there's no devicetree, go for legacy pdev probe */
+	if (!dev->of_node)
+		return mtk_dp_phy_legacy_probe(pdev, dp_phy);
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	dp_phy->regmap = devm_regmap_init_mmio(dev, base, &mtk_dp_phy_regmap_cfg);
+	if (IS_ERR(dp_phy->regmap))
+		return PTR_ERR(dp_phy->regmap);
+
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return ret;
+
 	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));
+
+	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (IS_ERR(provider))
+		return PTR_ERR(provider);
 
 	return 0;
 }
 
+static const struct of_device_id mtk_dp_phy_of_match[] = {
+	{ .compatible = "mediatek,mt8195-dp-phy" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mtk_dp_phy_of_match);
+
 static struct platform_driver mtk_dp_phy_driver = {
 	.probe = mtk_dp_phy_probe,
 	.driver = {
 		.name = "mediatek-dp-phy",
+		.of_match_table = mtk_dp_phy_of_match,
 	},
 };
 module_platform_driver(mtk_dp_phy_driver);
 
+MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
 MODULE_AUTHOR("Markus Schneider-Pargmann <msp@baylibre.com>");
-MODULE_DESCRIPTION("MediaTek DP PHY Driver");
+MODULE_DESCRIPTION("MediaTek DisplayPort PHY Driver");
 MODULE_LICENSE("GPL");
-- 
2.55.0

Re: [PATCH v4 03/12] phy: phy-mtk-dp: Allow probing with devicetree match

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:

New issues:
- [High] Hardcoded register offsets cause incorrect MMIO access or resource conflicts in the new OF probe path.

Pre-existing issues:
- [High] NULL pointer dereference when accessing platform_data before validation.
--

commit e5a7ed1fddd4b70c5e3f6f679c0fa4e43da6f22b
Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

phy: phy-mtk-dp: Allow probing with devicetree match

This commit decouples the DisplayPort PHY driver from the DisplayPort IP
driver by allowing it to probe via a devicetree match. When probed via
devicetree, it registers an OF PHY provider and maps its own MMIO regmap,
while retaining the legacy behavior in mtk_dp_phy_legacy_probe().

> diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
> index bf7b3a95e72d2..d241004e28286 100644
> --- a/drivers/phy/mediatek/phy-mtk-dp.c
> +++ b/drivers/phy/mediatek/phy-mtk-dp.c

[ ... ]

> @@ -160,43 +162,109 @@ static const struct phy_ops mtk_dp_phy_dev_ops = {
>  	.owner = THIS_MODULE,
>  };
>  
> +static void mtk_dp_phy_legacy_remove_lookup(void *data)
> +{
> +	struct phy *phy = data;
> +	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
> +
> +	phy_remove_lookup(phy, "dp", dev_name(dp_phy->dev));
> +}
> +
> +static int mtk_dp_phy_legacy_probe(struct platform_device *pdev, struct mtk_dp_phy *dp_phy)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct phy *phy;
> +	int ret;
> +
> +	dp_phy->regmap = *(struct regmap **)dev->platform_data;
> +	if (!dp_phy->regmap)
> +		return dev_err_probe(dev, -EINVAL, "No platform data available\n");

[Severity: High]
This is a pre-existing issue, but is it possible for dev->platform_data to be
NULL here? If the platform device is instantiated without platform_data
(for example, via a sysfs manual bind or driver core testing), dereferencing
it unconditionally before the validation check will cause a crash.

The code currently does:

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

The subsequent check if (!dp_phy->regmap) cannot prevent the crash if
dev->platform_data itself is NULL. Could we validate dev->platform_data
before attempting to dereference it?

> +
> +	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");

[ ... ]

> +static int mtk_dp_phy_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
> +	struct phy_provider *provider;
>  	struct mtk_dp_phy *dp_phy;
> +	void __iomem *base;
>  	struct phy *phy;
> -	struct regmap *regs;
> -
> -	regs = *(struct regmap **)dev->platform_data;
> -	if (!regs)
> -		return dev_err_probe(dev, -EINVAL,
> -				     "No data passed, requires struct regmap**\n");
> +	int ret;
>  
>  	dp_phy = devm_kzalloc(dev, sizeof(*dp_phy), GFP_KERNEL);
>  	if (!dp_phy)
>  		return -ENOMEM;
>  
> -	dp_phy->regmap = regs;
> +	dp_phy->dev = dev;
> +
> +	/* If there's no devicetree, go for legacy pdev probe */
> +	if (!dev->of_node)
> +		return mtk_dp_phy_legacy_probe(pdev, dp_phy);
> +
> +	base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	dp_phy->regmap = devm_regmap_init_mmio(dev, base, &mtk_dp_phy_regmap_cfg);

[Severity: High]
When mapping the dedicated MMIO region for the PHY in the new devicetree
match path, will the existing hardcoded register offsets cause out-of-bounds
accesses?

Looking at the existing phy data structures in this driver, offsets such as
.off_dig_glb = 0x1000 are used. These offsets appear to be relative to the
DP IP base address from the legacy shared regmap.

If the devicetree 'reg' property points to the PHY's actual physical
base address, using these hardcoded offsets on top of the new dedicated
MMIO mapping will overshoot the PHY registers by an additional 0x1000.

Alternatively, if the devicetree tries to compensate by pointing to the
DP IP base, wouldn't this cause a resource conflict (-EBUSY) with the
DP driver's own devm_platform_ioremap_resource() call?

> +	if (IS_ERR(dp_phy->regmap))
> +		return PTR_ERR(dp_phy->regmap);
> +
> +	ret = devm_pm_runtime_enable(dev);
> +	if (ret)
> +		return ret;
> +
>  	phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910092038.48291-1-angelogioacchino.delregno@collabora.com?part=3

[PATCH v4 04/12] phy: phy-mtk-dp: Migrate register offsets to SoC specific pdata

[AngeloGioacchino Del Regno]

In preparation for adding support for newer SoCs and for adding
more capabilities to this driver in an efficient manner, migrate
all of the hardcoded register offsets to SoC specific pdata and
assign that for both DT and platform probing.

While at it also cleanup writing the driving parameters to the PHY
by iterating through all lanes with a loop instead: note that for
that to happen the default 0/1/2 driving parameters were added,
those are really just zero.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 145 ++++++++++++++++++++++++------
 1 file changed, 116 insertions(+), 29 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index d241004e2828..20974650d940 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -4,6 +4,10 @@
  *
  * Copyright (c) 2022, BayLibre Inc.
  * Copyright (c) 2022, MediaTek Inc.
+ *
+ * Major refactoring
+ * Copyright (c) 2026, Collabora Ltd.
+ *                     AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
  */
 
 #include <linux/delay.h>
@@ -15,24 +19,29 @@
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 
-#define PHY_OFFSET			0x1000
+#define MTK_DP_PHY_MAX_LANES		4
 
-#define MTK_DP_PHY_DIG_PLL_CTL_1	(PHY_OFFSET + 0x14)
+/* DP_PHYD_PLL_CTL_1 */
 #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
+/* DP_PHYD_BIT_RATE */
+#define PHYD_DIG_RG_BIT_RATE		GENMASK(1, 0)
+#  define BIT_RATE_RBR			0
+#  define BIT_RATE_HBR			1
+#  define BIT_RATE_HBR2			2
+#  define BIT_RATE_HBR3			3
+
+/* DP_PHYD_SW_RST */
+#define PHYD_DIG_GLB_SW_RST_B		GENMASK(7, 0)
+#  define DP_GLB_SW_RST_PHYD		BIT(0)
+#  define DP_GLB_SW_RST_TFIFO_ANA	BIT(1)
+#  define DP_GLB_SW_RST_XTAL_CLK	BIT(2)
+#  define DP_GLB_SW_RST_MAIN_LINK	BIT(3)
 
-#define MTK_DP_PHY_DIG_SW_RST		(PHY_OFFSET + 0x38)
-#define DP_GLB_SW_RST_PHYD		BIT(0)
+#define DRIVING_PARAM_0_DEFAULT	0x0
+#define DRIVING_PARAM_1_DEFAULT	0x0
+#define DRIVING_PARAM_2_DEFAULT	0x0
 
-#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)
@@ -79,15 +88,62 @@
 #define DRIVING_PARAM_8_DEFAULT	(XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT | \
 				 XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
 
+enum mtk_dp_phyd_dig_lane_regidx {
+	DP_PHYD_LAN_DRIVING_PARAM_0,
+	DP_PHYD_LAN_MAX
+};
+
+enum mtk_dp_phyd_dig_glb_regidx {
+	DP_PHYD_PLL_CTL_0,
+	DP_PHYD_PLL_CTL_1,
+	DP_PHYD_SW_RST,
+	DP_PHYD_BIT_RATE,
+	DP_PHYD_GLOBAL_MAX
+};
+
+static const u8 mt8195_phy_dig_lane_regs[DP_PHYD_LAN_MAX] = {
+	[DP_PHYD_LAN_DRIVING_PARAM_0] = 0x2c,
+};
+
+static const u8 mt8195_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] = {
+	[DP_PHYD_PLL_CTL_0] = 0x10,
+	[DP_PHYD_PLL_CTL_1] = 0x14,
+	[DP_PHYD_SW_RST] = 0x38,
+	[DP_PHYD_BIT_RATE] = 0x3c,
+};
+
+/**
+ * struct mtk_dp_phy_pdata - Platform data and defaults for MediaTek DP/eDP PHY
+ * @off_dig_glb:    Base offset for dptx_phyd_sifslv_dig_glb
+ * @off_dig_lane:   Base offsets for dptx_phyd_sifslv_dig_lan (for each lane)
+ * @regs_dig_glb:   Register (layout) offsets for dig_glb
+ * @regs_dig_lane:  Register (layout) offsets for dig_lan
+ */
+struct mtk_dp_phy_pdata {
+	/* Register offsets */
+	u16 off_dig_glb;
+	u16 off_dig_lane[MTK_DP_PHY_MAX_LANES];
+
+	/* Register maps */
+	const u8 *regs_dig_glb;
+	const u8 *regs_dig_lane;
+};
+
 struct mtk_dp_phy {
 	struct device *dev;
 	struct regmap *regmap;
+	const struct mtk_dp_phy_pdata *pdata;
 };
 
 static int mtk_dp_phy_init(struct phy *phy)
 {
 	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
+	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
+	const u32 reg = pdata->regs_dig_lane[DP_PHYD_LAN_DRIVING_PARAM_0];
 	static const u32 driving_params[] = {
+		DRIVING_PARAM_0_DEFAULT,
+		DRIVING_PARAM_1_DEFAULT,
+		DRIVING_PARAM_2_DEFAULT,
 		DRIVING_PARAM_3_DEFAULT,
 		DRIVING_PARAM_4_DEFAULT,
 		DRIVING_PARAM_5_DEFAULT,
@@ -95,15 +151,21 @@ static int mtk_dp_phy_init(struct phy *phy)
 		DRIVING_PARAM_7_DEFAULT,
 		DRIVING_PARAM_8_DEFAULT
 	};
-
-	regmap_bulk_write(dp_phy->regmap, MTK_DP_LANE0_DRIVING_PARAM_3,
-			  driving_params, ARRAY_SIZE(driving_params));
-	regmap_bulk_write(dp_phy->regmap, MTK_DP_LANE1_DRIVING_PARAM_3,
-			  driving_params, ARRAY_SIZE(driving_params));
-	regmap_bulk_write(dp_phy->regmap, MTK_DP_LANE2_DRIVING_PARAM_3,
-			  driving_params, ARRAY_SIZE(driving_params));
-	regmap_bulk_write(dp_phy->regmap, MTK_DP_LANE3_DRIVING_PARAM_3,
-			  driving_params, ARRAY_SIZE(driving_params));
+	int i, ret;
+
+	/*
+	 * Assume that all lanes need the same driving parameters: this
+	 * will bulk write from DRIVING_PARAM_0 to DRIVING_PARAM_8 on
+	 * all lanes (a grand total of [9 * num_lanes] 32-bit writes)
+	 */
+	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++) {
+		ret = regmap_bulk_write(dp_phy->regmap,
+					pdata->off_dig_lane[i] + reg,
+					driving_params,
+					ARRAY_SIZE(driving_params));
+		if (ret)
+			return ret;
+	};
 
 	return 0;
 }
@@ -111,9 +173,12 @@ static int mtk_dp_phy_init(struct phy *phy)
 static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 {
 	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
+	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
 	u32 val;
 
 	if (opts->dp.set_rate) {
+		const u32 reg_bit_rate = pdata->regs_dig_glb[DP_PHYD_BIT_RATE];
+
 		switch (opts->dp.link_rate) {
 		default:
 			dev_err(&phy->dev,
@@ -133,10 +198,11 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 			val = BIT_RATE_HBR3;
 			break;
 		}
-		regmap_write(dp_phy->regmap, MTK_DP_PHY_DIG_BIT_RATE, val);
+		regmap_write(dp_phy->regmap, pdata->off_dig_glb + reg_bit_rate, val);
 	}
 
-	regmap_update_bits(dp_phy->regmap, MTK_DP_PHY_DIG_PLL_CTL_1,
+	regmap_update_bits(dp_phy->regmap,
+			   pdata->off_dig_glb + pdata->regs_dig_glb[DP_PHYD_PLL_CTL_1],
 			   TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0);
 
 	return 0;
@@ -145,12 +211,17 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 static int mtk_dp_phy_reset(struct phy *phy)
 {
 	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
+	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
+	const u32 reg_rst = pdata->regs_dig_glb[DP_PHYD_SW_RST];
+
+	/* Clearing bits sets reset state */
+	regmap_clear_bits(dp_phy->regmap, pdata->off_dig_glb + reg_rst, DP_GLB_SW_RST_PHYD);
 
-	regmap_update_bits(dp_phy->regmap, MTK_DP_PHY_DIG_SW_RST,
-			   DP_GLB_SW_RST_PHYD, 0);
+	/* PHYD needs 50uS to guarantee reset done */
 	usleep_range(50, 200);
-	regmap_update_bits(dp_phy->regmap, MTK_DP_PHY_DIG_SW_RST,
-			   DP_GLB_SW_RST_PHYD, 1);
+
+	/* Setting bits means go out of reset */
+	regmap_set_bits(dp_phy->regmap, pdata->off_dig_glb + reg_rst, DP_GLB_SW_RST_PHYD);
 
 	return 0;
 }
@@ -170,12 +241,19 @@ static void mtk_dp_phy_legacy_remove_lookup(void *data)
 	phy_remove_lookup(phy, "dp", dev_name(dp_phy->dev));
 }
 
+static const struct mtk_dp_phy_pdata mt8195_dp_phy_data;
+
 static int mtk_dp_phy_legacy_probe(struct platform_device *pdev, struct mtk_dp_phy *dp_phy)
 {
 	struct device *dev = &pdev->dev;
 	struct phy *phy;
 	int ret;
 
+	/*
+	 * If legacy platform driver probe, assume this is MT8195 or compatible
+	 * with a devicetree that was not migrated to the new, proper bindings.
+	 */
+	dp_phy->pdata = &mt8195_dp_phy_data;
 	dp_phy->regmap = *(struct regmap **)dev->platform_data;
 	if (!dp_phy->regmap)
 		return dev_err_probe(dev, -EINVAL, "No platform data available\n");
@@ -235,6 +313,8 @@ static int mtk_dp_phy_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	dp_phy->pdata = device_get_match_data(dev);
+
 	phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);
 	if (IS_ERR(phy))
 		return dev_err_probe(dev, PTR_ERR(phy),
@@ -249,8 +329,15 @@ static int mtk_dp_phy_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct mtk_dp_phy_pdata mt8195_dp_phy_data = {
+	.off_dig_glb = 0x1000,
+	.off_dig_lane = (const u16[]) { 0x1100, 0x1200, 0x1300, 0x1400 },
+	.regs_dig_glb = mt8195_phy_dig_glb_regs,
+	.regs_dig_lane = mt8195_phy_dig_lane_regs,
+};
+
 static const struct of_device_id mtk_dp_phy_of_match[] = {
-	{ .compatible = "mediatek,mt8195-dp-phy" },
+	{ .compatible = "mediatek,mt8195-dp-phy", .data = &mt8195_dp_phy_data },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, mtk_dp_phy_of_match);
-- 
2.55.0

Re: [PATCH v4 04/12] phy: phy-mtk-dp: Migrate register offsets to SoC specific pdata

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:

New issues:
- [High] Missing NULL check for `device_get_match_data()` leads to a NULL pointer dereference on manual sysfs bind.
- [High] Overlapping devicetree reg property and hardcoded offset prevents successful DT probe.

Pre-existing issues:
- [High] Potential NULL pointer dereference when accessing `dev->platform_data` prior to validation.
--

commit 6b41d18c7c7f31b8549b66b4262af72e2486491d
Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

phy: phy-mtk-dp: Migrate register offsets to SoC specific pdata
    
In preparation for adding support for newer SoCs and for adding
more capabilities to this driver in an efficient manner, migrate
all of the hardcoded register offsets to SoC specific pdata and
assign that for both DT and platform probing.

> diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
> index d241004e28286..20974650d9409 100644
> --- a/drivers/phy/mediatek/phy-mtk-dp.c
> +++ b/drivers/phy/mediatek/phy-mtk-dp.c
[ ... ]
> @@ -170,12 +241,19 @@ static void mtk_dp_phy_legacy_remove_lookup(void *data)
>  	phy_remove_lookup(phy, "dp", dev_name(dp_phy->dev));
>  }
>  
> +static const struct mtk_dp_phy_pdata mt8195_dp_phy_data;
> +
>  static int mtk_dp_phy_legacy_probe(struct platform_device *pdev, struct mtk_dp_phy *dp_phy)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct phy *phy;
>  	int ret;
>  
> +	/*
> +	 * If legacy platform driver probe, assume this is MT8195 or compatible
> +	 * with a devicetree that was not migrated to the new, proper bindings.
> +	 */
> +	dp_phy->pdata = &mt8195_dp_phy_data;
>  	dp_phy->regmap = *(struct regmap **)dev->platform_data;
>  	if (!dp_phy->regmap)
>  		return dev_err_probe(dev, -EINVAL, "No platform data available\n");

[Severity: High]
This isn't a bug introduced by this patch, but can this dereference
dev->platform_data before checking if it is NULL?

If the driver is manually bound via sysfs or a module without platform data
provided, it looks like it would crash immediately here:

drivers/phy/mediatek/phy-mtk-dp.c:mtk_dp_phy_legacy_probe() {
    ...
	dp_phy->regmap = *(struct regmap **)dev->platform_data;
	if (!dp_phy->regmap)
		return dev_err_probe(dev, -EINVAL, "No platform data available\n");
    ...
}

[ ... ]
> @@ -235,6 +313,8 @@ static int mtk_dp_phy_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> +	dp_phy->pdata = device_get_match_data(dev);
> +
>  	phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);
>  	if (IS_ERR(phy))
>  		return dev_err_probe(dev, PTR_ERR(phy),

[Severity: High]
Could this result in a NULL pointer dereference?

If the driver is manually bound (e.g., via driver_override in sysfs) to a
device that possesses an of_node but does not match any entry in
mtk_dp_phy_of_match, device_get_match_data() will return NULL.

This NULL pointer would later be dereferenced when accessing dp_phy->pdata
in mtk_dp_phy_init().

[ ... ]
> @@ -249,8 +329,15 @@ static int mtk_dp_phy_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static const struct mtk_dp_phy_pdata mt8195_dp_phy_data = {
> +	.off_dig_glb = 0x1000,
> +	.off_dig_lane = (const u16[]) { 0x1100, 0x1200, 0x1300, 0x1400 },
> +	.regs_dig_glb = mt8195_phy_dig_glb_regs,
> +	.regs_dig_lane = mt8195_phy_dig_lane_regs,
> +};
> +

[Severity: High]
Will these hardcoded offsets prevent a successful devicetree probe?

The driver maps its devicetree reg resource using
devm_platform_ioremap_resource() in mtk_dp_phy_probe():

drivers/phy/mediatek/phy-mtk-dp.c:mtk_dp_phy_probe() {
    ...
	base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(base))
		return PTR_ERR(base);
    ...
}

If the DT reg maps the specific PHY region, the driver will still add
0x1000 to the mapped base, accessing unmapped physical memory. 

If the DT reg maps the entire DP controller region to make the offsets work,
devm_platform_ioremap_resource() will fail with -EBUSY because the parent DP
driver already holds the request_mem_region lock.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910092038.48291-1-angelogioacchino.delregno@collabora.com?part=4

[PATCH v4 05/12] phy: phy-mtk-dp: Implement power_on and power_off PHY callbacks

[AngeloGioacchino Del Regno]

Add .power_on() and .power_off() callbacks to mtk_dp_phy_dev_ops
to be able to call those with phy_power_on() and phy_power_off()
API in the DisplayPort driver to be able to stop using all of
those hardcoded register writes in that external driver.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 68 +++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index 20974650d940..4247506ceb99 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -21,6 +21,9 @@
 
 #define MTK_DP_PHY_MAX_LANES		4
 
+/* DP_PHYA_GLB_FORCE_CTRL_1 */
+#define CKM_CKTX0_EN_FORCE_MODE		BIT(10)
+
 /* DP_PHYD_PLL_CTL_1 */
 #define TPLL_SSC_EN			BIT(3)
 
@@ -38,6 +41,11 @@
 #  define DP_GLB_SW_RST_XTAL_CLK	BIT(2)
 #  define DP_GLB_SW_RST_MAIN_LINK	BIT(3)
 
+/* DP_PHYD_AUX_RX_CTL */
+#define PHYD_DIG_DPAUX_RX_EN		BIT(0)
+#define PHYD_DIG_XTP_GLB_CKDET_EN	BIT(1)
+#define PHYD_DIG_DPAUX_RX_DEGLITCH_EN	BIT(2)
+
 #define DRIVING_PARAM_0_DEFAULT	0x0
 #define DRIVING_PARAM_1_DEFAULT	0x0
 #define DRIVING_PARAM_2_DEFAULT	0x0
@@ -88,6 +96,12 @@
 #define DRIVING_PARAM_8_DEFAULT	(XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT | \
 				 XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
 
+enum mtk_dp_phya_ana_glb_regidx {
+	DP_PHYA_GLB_FORCE_CTRL_0,
+	DP_PHYA_GLB_FORCE_CTRL_1,
+	DP_PHYA_GLOBAL_MAX
+};
+
 enum mtk_dp_phyd_dig_lane_regidx {
 	DP_PHYD_LAN_DRIVING_PARAM_0,
 	DP_PHYD_LAN_MAX
@@ -98,9 +112,15 @@ enum mtk_dp_phyd_dig_glb_regidx {
 	DP_PHYD_PLL_CTL_1,
 	DP_PHYD_SW_RST,
 	DP_PHYD_BIT_RATE,
+	DP_PHYD_AUX_RX_CTL,
 	DP_PHYD_GLOBAL_MAX
 };
 
+static const u8 mt8195_phy_ana_glb_regs[DP_PHYA_GLOBAL_MAX] = {
+	[DP_PHYA_GLB_FORCE_CTRL_0] = 0x30,
+	[DP_PHYA_GLB_FORCE_CTRL_1] = 0x34,
+};
+
 static const u8 mt8195_phy_dig_lane_regs[DP_PHYD_LAN_MAX] = {
 	[DP_PHYD_LAN_DRIVING_PARAM_0] = 0x2c,
 };
@@ -110,21 +130,26 @@ static const u8 mt8195_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] = {
 	[DP_PHYD_PLL_CTL_1] = 0x14,
 	[DP_PHYD_SW_RST] = 0x38,
 	[DP_PHYD_BIT_RATE] = 0x3c,
+	[DP_PHYD_AUX_RX_CTL] = 0x40,
 };
 
 /**
  * struct mtk_dp_phy_pdata - Platform data and defaults for MediaTek DP/eDP PHY
+ * @off_ana_glb:    Base offset for dptx_phyd_sifslv_ana_glb
  * @off_dig_glb:    Base offset for dptx_phyd_sifslv_dig_glb
  * @off_dig_lane:   Base offsets for dptx_phyd_sifslv_dig_lan (for each lane)
+ * @regs_ana_glb:   Register (layout) offsets for ana_glb
  * @regs_dig_glb:   Register (layout) offsets for dig_glb
  * @regs_dig_lane:  Register (layout) offsets for dig_lan
  */
 struct mtk_dp_phy_pdata {
 	/* Register offsets */
+	u16 off_ana_glb;
 	u16 off_dig_glb;
 	u16 off_dig_lane[MTK_DP_PHY_MAX_LANES];
 
 	/* Register maps */
+	const u8 *regs_ana_glb;
 	const u8 *regs_dig_glb;
 	const u8 *regs_dig_lane;
 };
@@ -208,6 +233,45 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 	return 0;
 }
 
+static int mtk_dp_phy_power_on(struct phy *phy)
+{
+	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
+	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
+	const u8 *regs_dig = pdata->regs_dig_glb;
+	const u8 *regs_ana = pdata->regs_ana_glb;
+
+	/* Enable AUX Channel with RX De-Glitch and input clock detection */
+	regmap_write(dp_phy->regmap,
+		     pdata->off_dig_glb + regs_dig[DP_PHYD_AUX_RX_CTL],
+		     PHYD_DIG_DPAUX_RX_EN |
+		     PHYD_DIG_XTP_GLB_CKDET_EN |
+		     PHYD_DIG_DPAUX_RX_DEGLITCH_EN);
+
+	regmap_clear_bits(dp_phy->regmap,
+			  pdata->off_ana_glb + regs_ana[DP_PHYA_GLB_FORCE_CTRL_1],
+			  CKM_CKTX0_EN_FORCE_MODE);
+
+	return 0;
+}
+
+static int mtk_dp_phy_power_off(struct phy *phy)
+{
+	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
+	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
+	const u8 *regs_dig = pdata->regs_dig_glb;
+	const u8 *regs_ana = pdata->regs_ana_glb;
+
+	regmap_set_bits(dp_phy->regmap,
+			pdata->off_ana_glb + regs_ana[DP_PHYA_GLB_FORCE_CTRL_1],
+			CKM_CKTX0_EN_FORCE_MODE);
+
+	/* Disable RX unconditionally */
+	regmap_write(dp_phy->regmap,
+		     pdata->off_dig_glb + regs_dig[DP_PHYD_AUX_RX_CTL], 0);
+
+	return 0;
+}
+
 static int mtk_dp_phy_reset(struct phy *phy)
 {
 	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
@@ -228,6 +292,8 @@ static int mtk_dp_phy_reset(struct phy *phy)
 
 static const struct phy_ops mtk_dp_phy_dev_ops = {
 	.init = mtk_dp_phy_init,
+	.power_on = mtk_dp_phy_power_on,
+	.power_off = mtk_dp_phy_power_off,
 	.configure = mtk_dp_phy_configure,
 	.reset = mtk_dp_phy_reset,
 	.owner = THIS_MODULE,
@@ -330,8 +396,10 @@ static int mtk_dp_phy_probe(struct platform_device *pdev)
 }
 
 static const struct mtk_dp_phy_pdata mt8195_dp_phy_data = {
+	.off_ana_glb = 0x0,
 	.off_dig_glb = 0x1000,
 	.off_dig_lane = (const u16[]) { 0x1100, 0x1200, 0x1300, 0x1400 },
+	.regs_ana_glb = mt8195_phy_ana_glb_regs,
 	.regs_dig_glb = mt8195_phy_dig_glb_regs,
 	.regs_dig_lane = mt8195_phy_dig_lane_regs,
 };
-- 
2.55.0

Re: [PATCH v4 05/12] phy: phy-mtk-dp: Implement power_on and power_off PHY callbacks

[Manivannan Sadhasivam]

On Thu, Sep 10, 2026 at 11:20:31AM +0200, AngeloGioacchino Del Regno wrote:
> Add .power_on() and .power_off() callbacks to mtk_dp_phy_dev_ops
> to be able to call those with phy_power_on() and phy_power_off()
> API in the DisplayPort driver to be able to stop using all of
> those hardcoded register writes in that external driver.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

- Mani

-- 
மணிவண்ணன் சதாசிவம்

[PATCH v4 06/12] phy: phy-mtk-dp: Support set_lanes in configure and properly cleanup

[AngeloGioacchino Del Regno]

Add support for enabling a specifically requested number of lanes
in the .configure() callback and disable all lanes in power off
and reset callbacks for proper hardware cleanup.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 57 +++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index 4247506ceb99..276391d991aa 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -10,6 +10,7 @@
  *                     AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/mfd/syscon.h>
@@ -50,6 +51,9 @@
 #define DRIVING_PARAM_1_DEFAULT	0x0
 #define DRIVING_PARAM_2_DEFAULT	0x0
 
+/* DP_PHYD_TX_CTL_0 */
+#define PHYD_TX_LN_EN			GENMASK(7, 4)
+
 #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)
@@ -113,6 +117,7 @@ enum mtk_dp_phyd_dig_glb_regidx {
 	DP_PHYD_SW_RST,
 	DP_PHYD_BIT_RATE,
 	DP_PHYD_AUX_RX_CTL,
+	DP_PHYD_TX_CTL_0,
 	DP_PHYD_GLOBAL_MAX
 };
 
@@ -131,6 +136,7 @@ static const u8 mt8195_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] = {
 	[DP_PHYD_SW_RST] = 0x38,
 	[DP_PHYD_BIT_RATE] = 0x3c,
 	[DP_PHYD_AUX_RX_CTL] = 0x40,
+	[DP_PHYD_TX_CTL_0] = 0x44,
 };
 
 /**
@@ -200,6 +206,7 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
 	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
 	u32 val;
+	int i;
 
 	if (opts->dp.set_rate) {
 		const u32 reg_bit_rate = pdata->regs_dig_glb[DP_PHYD_BIT_RATE];
@@ -226,6 +233,17 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 		regmap_write(dp_phy->regmap, pdata->off_dig_glb + reg_bit_rate, val);
 	}
 
+	if (opts->dp.set_lanes) {
+		const u32 reg_dig_tx_ctl = pdata->regs_dig_glb[DP_PHYD_TX_CTL_0];
+
+		val = 0;
+		for (i = 0; i < opts->dp.lanes; i++)
+			val |= FIELD_PREP(PHYD_TX_LN_EN, BIT(i));
+
+		regmap_update_bits(dp_phy->regmap, pdata->off_dig_glb + reg_dig_tx_ctl,
+				   PHYD_TX_LN_EN, val);
+	}
+
 	regmap_update_bits(dp_phy->regmap,
 			   pdata->off_dig_glb + pdata->regs_dig_glb[DP_PHYD_PLL_CTL_1],
 			   TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0);
@@ -254,12 +272,39 @@ static int mtk_dp_phy_power_on(struct phy *phy)
 	return 0;
 }
 
+static int mtk_dp_phy_disable_all_lanes(struct mtk_dp_phy *dp_phy)
+{
+	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
+	const u8 *regs = pdata->regs_dig_glb;
+	int ret;
+	u32 val;
+
+	/* Get mask of currently enabled lane */
+	regmap_read(dp_phy->regmap, pdata->off_dig_glb + regs[DP_PHYD_TX_CTL_0], &val);
+	val = FIELD_GET(PHYD_TX_LN_EN, val);
+	if (val == 0)
+		return 0;
+
+	/* Disable all lanes (needs to be done one by one, from last to first) */
+	do {
+		u32 lane_num = fls(val) - 1;
+		val &= ~BIT(lane_num);
+
+		regmap_clear_bits(dp_phy->regmap,
+				  pdata->off_dig_glb + regs[DP_PHYD_TX_CTL_0],
+				  FIELD_PREP(PHYD_TX_LN_EN, BIT(lane_num)));
+	} while (val);
+
+	return 0;
+}
+
 static int mtk_dp_phy_power_off(struct phy *phy)
 {
 	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
 	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
 	const u8 *regs_dig = pdata->regs_dig_glb;
 	const u8 *regs_ana = pdata->regs_ana_glb;
+	int ret;
 
 	regmap_set_bits(dp_phy->regmap,
 			pdata->off_ana_glb + regs_ana[DP_PHYA_GLB_FORCE_CTRL_1],
@@ -269,6 +314,12 @@ static int mtk_dp_phy_power_off(struct phy *phy)
 	regmap_write(dp_phy->regmap,
 		     pdata->off_dig_glb + regs_dig[DP_PHYD_AUX_RX_CTL], 0);
 
+	ret = mtk_dp_phy_disable_all_lanes(dp_phy);
+	if (ret) {
+		dev_err(dp_phy->dev, "Could not disable lanes for poweroff!\n");
+		return ret;
+	}
+
 	return 0;
 }
 
@@ -277,6 +328,7 @@ static int mtk_dp_phy_reset(struct phy *phy)
 	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
 	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
 	const u32 reg_rst = pdata->regs_dig_glb[DP_PHYD_SW_RST];
+	int ret;
 
 	/* Clearing bits sets reset state */
 	regmap_clear_bits(dp_phy->regmap, pdata->off_dig_glb + reg_rst, DP_GLB_SW_RST_PHYD);
@@ -287,6 +339,11 @@ static int mtk_dp_phy_reset(struct phy *phy)
 	/* Setting bits means go out of reset */
 	regmap_set_bits(dp_phy->regmap, pdata->off_dig_glb + reg_rst, DP_GLB_SW_RST_PHYD);
 
+	/* Disable all lanes and continue reset even if this fails, but notify */
+	ret = mtk_dp_phy_disable_all_lanes(dp_phy);
+	if (ret)
+		dev_err(dp_phy->dev, "Could not disable lanes during reset!\n");
+
 	return 0;
 }
 
-- 
2.55.0

Re: [PATCH v4 06/12] phy: phy-mtk-dp: Support set_lanes in configure and properly cleanup

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] mtk_dp_phy_disable_all_lanes() ignores the return value of regmap_read() and unconditionally returns 0, leading to uninitialized memory use and dead code.
--

commit 96237b9548980d0963b925da5fbae9fec554beb6
Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Subject: phy: phy-mtk-dp: Support set_lanes in configure and properly cleanup

This commit adds support for configuring a specific number of lanes
via the .configure() callback. It also introduces functionality to
disable all lanes during power-off and reset to ensure proper hardware
state cleanup.

> diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
> index 4247506ceb996..276391d991aae 100644
> --- a/drivers/phy/mediatek/phy-mtk-dp.c
> +++ b/drivers/phy/mediatek/phy-mtk-dp.c

[ ... ]

> @@ -254,12 +272,39 @@ static int mtk_dp_phy_power_on(struct phy *phy)
>  	return 0;
>  }
>  
> +static int mtk_dp_phy_disable_all_lanes(struct mtk_dp_phy *dp_phy)
> +{
> +	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
> +	const u8 *regs = pdata->regs_dig_glb;
> +	int ret;
> +	u32 val;
> +
> +	/* Get mask of currently enabled lane */
> +	regmap_read(dp_phy->regmap, pdata->off_dig_glb + regs[DP_PHYD_TX_CTL_0], &val);

[Severity: High]
Does this code handle the possibility of regmap_read() failing?

If regmap_read() returns an error (e.g., if the underlying bus or clock is in
an invalid state), it will not initialize val. In this scenario, the subsequent
operations would use uninitialized stack memory, potentially leading to random
lanes being disabled based on garbage data.

> +	val = FIELD_GET(PHYD_TX_LN_EN, val);
> +	if (val == 0)
> +		return 0;
> +
> +	/* Disable all lanes (needs to be done one by one, from last to first) */
> +	do {
> +		u32 lane_num = fls(val) - 1;
> +		val &= ~BIT(lane_num);
> +
> +		regmap_clear_bits(dp_phy->regmap,
> +				  pdata->off_dig_glb + regs[DP_PHYD_TX_CTL_0],
> +				  FIELD_PREP(PHYD_TX_LN_EN, BIT(lane_num)));
> +	} while (val);
> +
> +	return 0;

[Severity: High]
Should this function return the error state from the regmap operations?

It declares a ret variable but never uses it, and unconditionally returns 0.

> +}
> +
>  static int mtk_dp_phy_power_off(struct phy *phy)
>  {
>  	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
>  	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
>  	const u8 *regs_dig = pdata->regs_dig_glb;
>  	const u8 *regs_ana = pdata->regs_ana_glb;
> +	int ret;
>  
>  	regmap_set_bits(dp_phy->regmap,
>  			pdata->off_ana_glb + regs_ana[DP_PHYA_GLB_FORCE_CTRL_1],
> @@ -269,6 +314,12 @@ static int mtk_dp_phy_power_off(struct phy *phy)
>  	regmap_write(dp_phy->regmap,
>  		     pdata->off_dig_glb + regs_dig[DP_PHYD_AUX_RX_CTL], 0);
>  
> +	ret = mtk_dp_phy_disable_all_lanes(dp_phy);
> +	if (ret) {
> +		dev_err(dp_phy->dev, "Could not disable lanes for poweroff!\n");
> +		return ret;
> +	}

[Severity: High]
Since mtk_dp_phy_disable_all_lanes() unconditionally returns 0, this error
handling block appears to be dead code, preventing the driver from properly
detecting hardware state failures during cleanup.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910092038.48291-1-angelogioacchino.delregno@collabora.com?part=6

Re: [PATCH v4 06/12] phy: phy-mtk-dp: Support set_lanes in configure and properly cleanup

[Manivannan Sadhasivam]

On Thu, Sep 10, 2026 at 11:20:32AM +0200, AngeloGioacchino Del Regno wrote:
> Add support for enabling a specifically requested number of lanes
> in the .configure() callback and disable all lanes in power off
> and reset callbacks for proper hardware cleanup.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

- Mani

-- 
மணிவண்ணன் சதாசிவம்

[PATCH v4 07/12] phy: phy-mtk-dp: Support setting volt swing and preemphasis values

[AngeloGioacchino Del Regno]

Add support for honoring the set_voltages request to set the
voltage swing and preemphasis values in the .configure() callback.

For proper hardware cleanup, reset both in the .reset() callback.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 44 ++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index 276391d991aa..692049f78833 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -54,6 +54,11 @@
 /* DP_PHYD_TX_CTL_0 */
 #define PHYD_TX_LN_EN			GENMASK(7, 4)
 
+/* DP_PHYD_DRIVING_FORCE */
+#define PHYD_DP_TX_FORCE_VOLT_SWING_EN	BIT(0)
+#define PHYD_DP_TX_FORCE_VOLT_SWING_VAL	GENMASK(2, 1)
+#define PHYD_DP_TX_FORCE_PRE_EMPH_VAL	GENMASK(4, 3)
+
 #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)
@@ -107,6 +112,7 @@ enum mtk_dp_phya_ana_glb_regidx {
 };
 
 enum mtk_dp_phyd_dig_lane_regidx {
+	DP_PHYD_LAN_DRIVING_FORCE,
 	DP_PHYD_LAN_DRIVING_PARAM_0,
 	DP_PHYD_LAN_MAX
 };
@@ -127,6 +133,7 @@ static const u8 mt8195_phy_ana_glb_regs[DP_PHYA_GLOBAL_MAX] = {
 };
 
 static const u8 mt8195_phy_dig_lane_regs[DP_PHYD_LAN_MAX] = {
+	[DP_PHYD_LAN_DRIVING_FORCE] = 0x18,
 	[DP_PHYD_LAN_DRIVING_PARAM_0] = 0x2c,
 };
 
@@ -244,6 +251,30 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 				   PHYD_TX_LN_EN, val);
 	}
 
+	if (opts->dp.set_voltages) {
+		const u32 reg_drv_force = pdata->regs_dig_lane[DP_PHYD_LAN_DRIVING_FORCE];
+
+		if (opts->dp.lanes > 4) {
+			dev_err(&phy->dev, "Wrong lanes config %u\n", opts->dp.lanes);
+			return -EINVAL;
+		}
+
+		for (i = 0; i < opts->dp.lanes; i++) {
+			const u32 off_dig_lane = pdata->off_dig_lane[i];
+			u32 val;
+
+			val = FIELD_PREP(PHYD_DP_TX_FORCE_VOLT_SWING_VAL, opts->dp.voltage[i]);
+			val |= FIELD_PREP(PHYD_DP_TX_FORCE_PRE_EMPH_VAL, opts->dp.pre[i]);
+			val |= PHYD_DP_TX_FORCE_VOLT_SWING_EN;
+
+			regmap_update_bits(dp_phy->regmap, off_dig_lane + reg_drv_force,
+					   PHYD_DP_TX_FORCE_VOLT_SWING_EN |
+					   PHYD_DP_TX_FORCE_VOLT_SWING_VAL |
+					   PHYD_DP_TX_FORCE_PRE_EMPH_VAL,
+					   val);
+		}
+	}
+
 	regmap_update_bits(dp_phy->regmap,
 			   pdata->off_dig_glb + pdata->regs_dig_glb[DP_PHYD_PLL_CTL_1],
 			   TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0);
@@ -328,7 +359,8 @@ static int mtk_dp_phy_reset(struct phy *phy)
 	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
 	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
 	const u32 reg_rst = pdata->regs_dig_glb[DP_PHYD_SW_RST];
-	int ret;
+	const u32 reg_drv_force = pdata->regs_dig_lane[DP_PHYD_LAN_DRIVING_FORCE];
+	int i, ret;
 
 	/* Clearing bits sets reset state */
 	regmap_clear_bits(dp_phy->regmap, pdata->off_dig_glb + reg_rst, DP_GLB_SW_RST_PHYD);
@@ -344,6 +376,16 @@ static int mtk_dp_phy_reset(struct phy *phy)
 	if (ret)
 		dev_err(dp_phy->dev, "Could not disable lanes during reset!\n");
 
+	/* Reset Voltage Swing and Preemphasis values */
+	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++) {
+		const u32 off_dig_lane = pdata->off_dig_lane[i];
+
+		regmap_clear_bits(dp_phy->regmap, off_dig_lane + reg_drv_force,
+				   PHYD_DP_TX_FORCE_VOLT_SWING_EN |
+				   PHYD_DP_TX_FORCE_VOLT_SWING_VAL |
+				   PHYD_DP_TX_FORCE_PRE_EMPH_VAL);
+	}
+
 	return 0;
 }
 
-- 
2.55.0

[PATCH v4 08/12] phy: phy-mtk-dp: Add support for digital and analog calibration

[AngeloGioacchino Del Regno]

Add support for reading the calibration values from eFuse: if
present, write those - otherwise, rely on the defaults from
SoC-specific data.
This also adds support for writing the calibration values for
the analog part of the PHY.

Note that before this change, only default hardcoded calibration
values were supported for the digital driving parameters.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 289 +++++++++++++++++++++++++++---
 1 file changed, 261 insertions(+), 28 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index 692049f78833..2f4cf52d922c 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -14,6 +14,7 @@
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/mfd/syscon.h>
+#include <linux/nvmem-consumer.h>
 #include <linux/of.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
@@ -22,6 +23,19 @@
 
 #define MTK_DP_PHY_MAX_LANES		4
 
+/* DP_PHYA_GLB_BIAS_GEN_0 (PHYA - Analog) */
+#define XTP_GLB_BIAS_INT_R_CTRL		GENMASK(20, 16)
+
+/* DP_PHYA_GLB_FORCE_CTRL_1 */
+#define CKM_CKTX0_EN_FORCE_MODE		BIT(10)
+
+/* DP_PHYA_GLB_DPAUX_TX */
+#define CKM_PT0_CKTX_IMPSEL		GENMASK(23, 20)
+
+/* DP_PHYA_LAN_LANE_TX_0 */
+#define XTP_LN_TX_IMPSEL_PMOS		GENMASK(15, 12)
+#define XTP_LN_TX_IMPSEL_NMOS		GENMASK(19, 16)
+
 /* DP_PHYA_GLB_FORCE_CTRL_1 */
 #define CKM_CKTX0_EN_FORCE_MODE		BIT(10)
 
@@ -59,11 +73,29 @@
 #define PHYD_DP_TX_FORCE_VOLT_SWING_VAL	GENMASK(2, 1)
 #define PHYD_DP_TX_FORCE_PRE_EMPH_VAL	GENMASK(4, 3)
 
+/*
+ * DRIVING_PARAM_X (PHYD - Digital)
+ *
+ * Driving param registers are split in three sets, all containing settings
+ * for Voltage Swing and Pre-Emphasis for each lane's differential pair.
+ *
+ * All three sets share the same layout, but for different physical signals;
+ * In particular:
+ * [0-2]: LC TX CM (Minus / Negative Edge)
+ * [3-5]: LC TX C  (Logic State Change Point)
+ * [6-8]: LC TX CP (Plus / Positive Edge)
+ *
+ * And they contain values for:
+ * [0,3,6]: Swing 0 Pre[0-3]
+ * [1,4,7]: Swing 1 Pre[0-2] and Swing 2 Pre0
+ * [2,5,8]: Swing 2 Pre1 and Swing 3 Pre0
+ */
+#define PHYD_DIG_NUM_DRV_PARA_REGS	9
 #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 | \
+#define MT8195_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)
@@ -72,21 +104,21 @@
 #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 | \
+#define MT8195_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 | \
+#define MT8195_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 | \
+#define MT8195_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)
@@ -95,22 +127,30 @@
 #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 | \
+#define MT8195_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 | \
+#define MT8195_DRIVING_PARAM_8_DEFAULT	(XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT | \
 				 XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
 
 enum mtk_dp_phya_ana_glb_regidx {
+	DP_PHYA_GLB_BIAS_GEN_0,
+	DP_PHYA_GLB_BIAS_GEN_1,
+	DP_PHYA_GLB_DPAUX_TX,
 	DP_PHYA_GLB_FORCE_CTRL_0,
 	DP_PHYA_GLB_FORCE_CTRL_1,
 	DP_PHYA_GLOBAL_MAX
 };
 
+enum mtk_dp_phya_ana_lane_regidx {
+	DP_PHYA_LAN_LANE_TX_0,
+	DP_PHYA_LAN_MAX
+};
+
 enum mtk_dp_phyd_dig_lane_regidx {
 	DP_PHYD_LAN_DRIVING_FORCE,
 	DP_PHYD_LAN_DRIVING_PARAM_0,
@@ -128,10 +168,17 @@ enum mtk_dp_phyd_dig_glb_regidx {
 };
 
 static const u8 mt8195_phy_ana_glb_regs[DP_PHYA_GLOBAL_MAX] = {
+	[DP_PHYA_GLB_BIAS_GEN_0] = 0x0,
+	[DP_PHYA_GLB_BIAS_GEN_1] = 0x4,
+	[DP_PHYA_GLB_DPAUX_TX] = 0x8,
 	[DP_PHYA_GLB_FORCE_CTRL_0] = 0x30,
 	[DP_PHYA_GLB_FORCE_CTRL_1] = 0x34,
 };
 
+static const u8 mt8195_phy_ana_lane_regs[DP_PHYA_LAN_MAX] = {
+	[DP_PHYA_LAN_LANE_TX_0] = 0x4,
+};
+
 static const u8 mt8195_phy_dig_lane_regs[DP_PHYD_LAN_MAX] = {
 	[DP_PHYD_LAN_DRIVING_FORCE] = 0x18,
 	[DP_PHYD_LAN_DRIVING_PARAM_0] = 0x2c,
@@ -146,49 +193,94 @@ static const u8 mt8195_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] = {
 	[DP_PHYD_TX_CTL_0] = 0x44,
 };
 
+/**
+ * struct mtk_dp_phya_imp_sel - Per-Lane Impedance Selection
+ * @pmos: Impedance selection for P-Channel MOSFET
+ * @nmos: Impedance selection for N-Channel MOSFET
+ */
+struct mtk_dp_phya_imp_sel {
+	u8 pmos : 4;
+	u8 nmos : 4;
+};
+
 /**
  * struct mtk_dp_phy_pdata - Platform data and defaults for MediaTek DP/eDP PHY
  * @off_ana_glb:    Base offset for dptx_phyd_sifslv_ana_glb
+ * @off_ana_lane:   Base offsets for dptx_phyd_sifslv_ana_lan (for each lane)
  * @off_dig_glb:    Base offset for dptx_phyd_sifslv_dig_glb
  * @off_dig_lane:   Base offsets for dptx_phyd_sifslv_dig_lan (for each lane)
  * @regs_ana_glb:   Register (layout) offsets for ana_glb
+ * @regs_ana_lane:  Register (layout) offsets for ana_lan
  * @regs_dig_glb:   Register (layout) offsets for dig_glb
  * @regs_dig_lane:  Register (layout) offsets for dig_lan
+ * @ana_bias_r:     Internal resistance "R" Selection Settings (global)
+ * @ana_cktx_imp:   TX Clock Impedance Selection Settings (global)
+ * @ana_lanes_imp:  TX Impedance Selection Settings (for all lanes)
+ * @driving_params: Voltage Swing and Pre-Emphasis settings (for all lanes)
  */
 struct mtk_dp_phy_pdata {
 	/* Register offsets */
 	u16 off_ana_glb;
+	u16 off_ana_lane[MTK_DP_PHY_MAX_LANES];
 	u16 off_dig_glb;
 	u16 off_dig_lane[MTK_DP_PHY_MAX_LANES];
 
 	/* Register maps */
 	const u8 *regs_ana_glb;
+	const u8 *regs_ana_lane;
 	const u8 *regs_dig_glb;
 	const u8 *regs_dig_lane;
+
+	/* Calibration defaults */
+	u8 ana_bias_r;
+	u8 ana_cktx_imp;
+	struct mtk_dp_phya_imp_sel ana_lanes_imp;
+	u32 driving_params[PHYD_DIG_NUM_DRV_PARA_REGS];
 };
 
 struct mtk_dp_phy {
 	struct device *dev;
 	struct regmap *regmap;
 	const struct mtk_dp_phy_pdata *pdata;
+
+	u8 ana_bias_r;
+	u8 ana_cktx_imp;
+	struct mtk_dp_phya_imp_sel ana_impsel[MTK_DP_PHY_MAX_LANES];
 };
 
-static int mtk_dp_phy_init(struct phy *phy)
+static void mtk_dp_phy_set_analog_calibration_params(struct mtk_dp_phy *dp_phy)
+{
+	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
+	const u8 *regs_ana_glb = pdata->regs_ana_glb;
+	const u8 *regs_ana_lane = pdata->regs_ana_lane;
+	int i;
+
+	regmap_update_bits(dp_phy->regmap,
+			   pdata->off_ana_glb + regs_ana_glb[DP_PHYA_GLB_BIAS_GEN_0],
+			   XTP_GLB_BIAS_INT_R_CTRL,
+			   FIELD_PREP(XTP_GLB_BIAS_INT_R_CTRL, dp_phy->ana_bias_r));
+
+	regmap_update_bits(dp_phy->regmap,
+			   pdata->off_ana_glb + regs_ana_glb[DP_PHYA_GLB_DPAUX_TX],
+			   CKM_PT0_CKTX_IMPSEL,
+			   FIELD_PREP(CKM_PT0_CKTX_IMPSEL, dp_phy->ana_cktx_imp));
+
+	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++) {
+		struct mtk_dp_phya_imp_sel *ana_imp = &dp_phy->ana_impsel[i];
+		u32 val = FIELD_PREP(XTP_LN_TX_IMPSEL_PMOS, ana_imp->pmos) |
+			  FIELD_PREP(XTP_LN_TX_IMPSEL_NMOS, ana_imp->nmos);
+		u32 off_ana_lane = pdata->off_ana_lane[i];
+
+		regmap_update_bits(dp_phy->regmap,
+				   off_ana_lane + regs_ana_lane[DP_PHYA_LAN_LANE_TX_0],
+				   XTP_LN_TX_IMPSEL_PMOS | XTP_LN_TX_IMPSEL_NMOS, val);
+	}
+}
+
+static void mtk_dp_phy_set_digital_drv_params(struct mtk_dp_phy *dp_phy)
 {
-	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
 	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
 	const u32 reg = pdata->regs_dig_lane[DP_PHYD_LAN_DRIVING_PARAM_0];
-	static const u32 driving_params[] = {
-		DRIVING_PARAM_0_DEFAULT,
-		DRIVING_PARAM_1_DEFAULT,
-		DRIVING_PARAM_2_DEFAULT,
-		DRIVING_PARAM_3_DEFAULT,
-		DRIVING_PARAM_4_DEFAULT,
-		DRIVING_PARAM_5_DEFAULT,
-		DRIVING_PARAM_6_DEFAULT,
-		DRIVING_PARAM_7_DEFAULT,
-		DRIVING_PARAM_8_DEFAULT
-	};
 	int i, ret;
 
 	/*
@@ -196,14 +288,19 @@ static int mtk_dp_phy_init(struct phy *phy)
 	 * will bulk write from DRIVING_PARAM_0 to DRIVING_PARAM_8 on
 	 * all lanes (a grand total of [9 * num_lanes] 32-bit writes)
 	 */
-	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++) {
-		ret = regmap_bulk_write(dp_phy->regmap,
-					pdata->off_dig_lane[i] + reg,
-					driving_params,
-					ARRAY_SIZE(driving_params));
-		if (ret)
-			return ret;
-	};
+	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++)
+		regmap_bulk_write(dp_phy->regmap, pdata->off_dig_lane[i] + reg,
+				  pdata->driving_params,
+				  ARRAY_SIZE(pdata->driving_params));
+}
+
+static int mtk_dp_phy_init(struct phy *phy)
+{
+	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
+	struct device *dev = &phy->dev;
+
+	mtk_dp_phy_set_digital_drv_params(dp_phy);
+	mtk_dp_phy_set_analog_calibration_params(dp_phy);
 
 	return 0;
 }
@@ -398,6 +495,107 @@ static const struct phy_ops mtk_dp_phy_dev_ops = {
 	.owner = THIS_MODULE,
 };
 
+static void mtk_dp_phy_get_default_cal_data(struct mtk_dp_phy *dp_phy)
+{
+	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
+	int i;
+
+	dp_phy->ana_bias_r = pdata->ana_bias_r;
+	dp_phy->ana_cktx_imp = pdata->ana_cktx_imp;
+
+	/* Copy the default lane impedance settings to all lanes */
+	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++)
+		memcpy(&dp_phy->ana_impsel[i], &pdata->ana_lanes_imp,
+		       sizeof(dp_phy->ana_impsel[0]));
+
+	return;
+}
+
+static int mtk_dp_phy_get_one_cal_para(struct device *dev, const char *name, u8 max_val)
+{
+	u8 buf_byte;
+	u16 buf;
+	int ret;
+
+	/*
+	 * All of the calibrations are always max 8 bits long, but some may
+	 * be split between two different 8-bits cells: handle this corner
+	 * case by retrying reading as u16.
+	 */
+	ret = nvmem_cell_read_u8(dev, name, &buf_byte);
+	if (ret)
+		ret = nvmem_cell_read_u16(dev, name, &buf);
+	else
+		buf = buf_byte;
+
+	if (ret)
+		return dev_err_probe(dev, ret, "Cannot get calibration data for %s\n", name);
+
+	if (buf == 0) {
+		dev_warn(dev, "No calibration for %s. Using defaults\n", name);
+		return -ENOENT;
+	}
+
+	if (buf > max_val)
+		return dev_err_probe(dev, -ERANGE, "Bad value %u retrieved for %s\n", buf, name);
+
+	return buf;
+}
+
+static int mtk_dp_phy_get_calibration_data(struct mtk_dp_phy *dp_phy)
+{
+	char mtk_dp_cal_lane_imp_name[] = "impedance-laneXM";
+	struct device *dev = dp_phy->dev;
+	int i, ret;
+
+	ret = mtk_dp_phy_get_one_cal_para(dev, "rbias-trim", FIELD_MAX(XTP_GLB_BIAS_INT_R_CTRL));
+	if (ret < 0)
+		goto end;
+	dp_phy->ana_bias_r = ret;
+
+	ret = mtk_dp_phy_get_one_cal_para(dev, "impedance-txclk", FIELD_MAX(CKM_PT0_CKTX_IMPSEL));
+	if (ret < 0)
+		goto end;
+	dp_phy->ana_cktx_imp = ret;
+
+	/* Get impedance params for each lane */
+	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++) {
+		/* P-MOSFET first */
+		snprintf(mtk_dp_cal_lane_imp_name, ARRAY_SIZE(mtk_dp_cal_lane_imp_name),
+			 "impedance-lane%dp", i);
+		ret = mtk_dp_phy_get_one_cal_para(dev, mtk_dp_cal_lane_imp_name,
+						  FIELD_MAX(XTP_LN_TX_IMPSEL_PMOS));
+		if (ret < 0)
+			goto end;
+		dp_phy->ana_impsel[i].pmos = ret;
+
+		/* ...and then N-MOSFET too */
+		snprintf(mtk_dp_cal_lane_imp_name, ARRAY_SIZE(mtk_dp_cal_lane_imp_name),
+			 "impedance-lane%dn", i);
+		ret = mtk_dp_phy_get_one_cal_para(dev, mtk_dp_cal_lane_imp_name,
+						  FIELD_MAX(XTP_LN_TX_IMPSEL_NMOS));
+		if (ret < 0)
+			goto end;
+		dp_phy->ana_impsel[i].nmos = ret;
+	}
+end:
+	if (ret < 0) {
+		/*
+		 * If any of the calibration values is missing, or if there
+		 * is no calibration at all in the eFuses, copy the default
+		 * one entirely (as partial values shall not be mixed!)
+		 */
+		if (ret == -ENOENT) {
+			dev_info(dev, "Using calibration default values\n");
+			mtk_dp_phy_get_default_cal_data(dp_phy);
+			return 0;
+		}
+		return ret;
+	};
+
+	return 0;
+}
+
 static void mtk_dp_phy_legacy_remove_lookup(void *data)
 {
 	struct phy *phy = data;
@@ -429,6 +627,13 @@ static int mtk_dp_phy_legacy_probe(struct platform_device *pdev, struct mtk_dp_p
 				     "Failed to create DP PHY\n");
 
 	phy_set_drvdata(phy, dp_phy);
+
+	/*
+	 * Set default calibration data before exposing the PHY.
+	 * For legacy probe, mtk_dp will set calibrations from eFuse, if found.
+	 */
+	mtk_dp_phy_get_default_cal_data(dp_phy);
+
 	ret = phy_create_lookup(phy, "dp", dev_name(dev));
 	if (ret)
 		return ret;
@@ -480,6 +685,15 @@ static int mtk_dp_phy_probe(struct platform_device *pdev)
 
 	dp_phy->pdata = device_get_match_data(dev);
 
+	if (IS_REACHABLE(CONFIG_NVMEM)) {
+		ret = mtk_dp_phy_get_calibration_data(dp_phy);
+		if (ret)
+			return ret;
+	} else {
+		/* Use default calibration data */
+		mtk_dp_phy_get_default_cal_data(dp_phy);
+	}
+
 	phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);
 	if (IS_ERR(phy))
 		return dev_err_probe(dev, PTR_ERR(phy),
@@ -495,12 +709,31 @@ static int mtk_dp_phy_probe(struct platform_device *pdev)
 }
 
 static const struct mtk_dp_phy_pdata mt8195_dp_phy_data = {
-	.off_ana_glb = 0x0,
+	.off_ana_glb = 0,
+	.off_ana_lane = (const u16[]) { 0x100, 0x200, 0x300, 0x400 },
 	.off_dig_glb = 0x1000,
 	.off_dig_lane = (const u16[]) { 0x1100, 0x1200, 0x1300, 0x1400 },
 	.regs_ana_glb = mt8195_phy_ana_glb_regs,
+	.regs_ana_lane = mt8195_phy_ana_lane_regs,
 	.regs_dig_glb = mt8195_phy_dig_glb_regs,
 	.regs_dig_lane = mt8195_phy_dig_lane_regs,
+	.ana_bias_r = 15,
+	.ana_cktx_imp = 8,
+	.ana_lanes_imp = {
+		.pmos = 8,
+		.nmos = 8,
+	},
+	.driving_params = (const u32[]) {
+		[0] = 0,
+		[1] = 0,
+		[2] = 0,
+		[3] = MT8195_DRIVING_PARAM_3_DEFAULT,
+		[4] = MT8195_DRIVING_PARAM_4_DEFAULT,
+		[5] = MT8195_DRIVING_PARAM_5_DEFAULT,
+		[6] = MT8195_DRIVING_PARAM_6_DEFAULT,
+		[7] = MT8195_DRIVING_PARAM_7_DEFAULT,
+		[8] = MT8195_DRIVING_PARAM_8_DEFAULT
+	},
 };
 
 static const struct of_device_id mtk_dp_phy_of_match[] = {
-- 
2.55.0

Re: [PATCH v4 08/12] phy: phy-mtk-dp: Add support for digital and analog calibration

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [Medium] Silent ignoring of hardware write failures during PHY initialization.
- [Medium] False positive error logs emitted when optional eFuse calibration data is missing.
- [Low] Unused variables left over from refactoring (`dev` and `ret`).
--

commit 7b4b9550381f2fc0574d6e28361a57bed4016c26
Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

phy: phy-mtk-dp: Add support for digital and analog calibration

This commit adds support for reading DP PHY calibration values from eFuse.
If calibration values are present, they are written to the PHY; otherwise,
the driver falls back to default SoC-specific values. It also adds support
for writing the calibration values for the analog part of the PHY.

> diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
> index 692049f788332..2f4cf52d922c1 100644
> --- a/drivers/phy/mediatek/phy-mtk-dp.c
> +++ b/drivers/phy/mediatek/phy-mtk-dp.c
[ ... ]
> -static int mtk_dp_phy_init(struct phy *phy)
> +static void mtk_dp_phy_set_digital_drv_params(struct mtk_dp_phy *dp_phy)
>  {
> -	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
>  	const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
>  	const u32 reg = pdata->regs_dig_lane[DP_PHYD_LAN_DRIVING_PARAM_0];
> -	static const u32 driving_params[] = {
[ ... ]
> -	};
>  	int i, ret;

[Severity: Low]
Is `ret` still needed here? The return checks for regmap bulk writes were
removed below, which appears to leave this variable completely unused.

>  
>  	/*
[ ... ]
> -	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++) {
> -		ret = regmap_bulk_write(dp_phy->regmap,
> -					pdata->off_dig_lane[i] + reg,
> -					driving_params,
> -					ARRAY_SIZE(driving_params));
> -		if (ret)
> -			return ret;
> -	};
> +	for (i = 0; i < MTK_DP_PHY_MAX_LANES; i++)
> +		regmap_bulk_write(dp_phy->regmap, pdata->off_dig_lane[i] + reg,
> +				  pdata->driving_params,
> +				  ARRAY_SIZE(pdata->driving_params));
> +}

[Severity: Medium]
Does this code introduce a regression by silently ignoring hardware write
failures during PHY initialization?

Prior to this patch, if regmap_bulk_write() failed, the error was propagated
back to the caller. Now that this has been extracted into a void function,
any hardware or bus errors during these bulk writes will be silently dropped.

> +
> +static int mtk_dp_phy_init(struct phy *phy)
> +{
> +	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
> +	struct device *dev = &phy->dev;

[Severity: Low]
Is the `dev` variable used anywhere in this function? It appears to be
declared and assigned but never utilized.

> +
> +	mtk_dp_phy_set_digital_drv_params(dp_phy);
> +	mtk_dp_phy_set_analog_calibration_params(dp_phy);
>  
>  	return 0;
>  }

[Severity: Medium]
Does the PHY initialization now unconditionally succeed regardless of
the underlying hardware state?

Because the extracted functions mtk_dp_phy_set_digital_drv_params() and
mtk_dp_phy_set_analog_calibration_params() return void, any failures
during regmap updates will not be caught, and this function will always
improperly return 0 on failure.

[ ... ]
> +static int mtk_dp_phy_get_one_cal_para(struct device *dev, const char *name, u8 max_val)
> +{
> +	u8 buf_byte;
> +	u16 buf;
> +	int ret;
> +
[ ... ]
> +	ret = nvmem_cell_read_u8(dev, name, &buf_byte);
> +	if (ret)
> +		ret = nvmem_cell_read_u16(dev, name, &buf);
> +	else
> +		buf = buf_byte;
> +
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Cannot get calibration data for %s\n", name);

[Severity: Medium]
Will this cause false positive error logs on normal boots?

If an NVMEM cell is missing, the nvmem read functions naturally return
-ENOENT. This dev_err_probe() triggers a KERN_ERR log here before returning
the error to the caller.

> +
> +	if (buf == 0) {
[ ... ]
> +static int mtk_dp_phy_get_calibration_data(struct mtk_dp_phy *dp_phy)
> +{
[ ... ]
> +end:
> +	if (ret < 0) {
> +		/*
> +		 * If any of the calibration values is missing, or if there
> +		 * is no calibration at all in the eFuses, copy the default
> +		 * one entirely (as partial values shall not be mixed!)
> +		 */
> +		if (ret == -ENOENT) {
> +			dev_info(dev, "Using calibration default values\n");
> +			mtk_dp_phy_get_default_cal_data(dp_phy);
> +			return 0;
> +		}

[Severity: Medium]
Since -ENOENT is explicitly checked and handled gracefully as a benign
fallback here, should we avoid logging it as an error in
mtk_dp_phy_get_one_cal_para() earlier?

Logging an expected missing cell as an error falsely spams the kernel dmesg
with an error trace for boards that legitimately omit calibration data.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260910092038.48291-1-angelogioacchino.delregno@collabora.com?part=8

Re: [PATCH v4 08/12] phy: phy-mtk-dp: Add support for digital and analog calibration

[Manivannan Sadhasivam]

On Thu, Sep 10, 2026 at 11:20:34AM +0200, AngeloGioacchino Del Regno wrote:
> Add support for reading the calibration values from eFuse: if
> present, write those - otherwise, rely on the defaults from
> SoC-specific data.
> This also adds support for writing the calibration values for
> the analog part of the PHY.
> 
> Note that before this change, only default hardcoded calibration
> values were supported for the digital driving parameters.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

- Mani

-- 
மணிவண்ணன் சதாசிவம்

[PATCH v4 09/12] phy: phy-mtk-dp: Rewrite and document default driving param macros

[AngeloGioacchino Del Regno]

Use FIELD_PREP_CONST and add nicer definitions/macros to build the
default driving parameters for the PHY and, while at it, also add
comments explaining what they are supposed to set in the PHY.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 86 +++++++++++++++----------------
 1 file changed, 41 insertions(+), 45 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index 2f4cf52d922c..8e1fc4e16ba6 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -91,51 +91,47 @@
  * [2,5,8]: Swing 2 Pre1 and Swing 3 Pre0
  */
 #define PHYD_DIG_NUM_DRV_PARA_REGS	9
-#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 MT8195_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 MT8195_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 MT8195_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 MT8195_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 MT8195_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 MT8195_DRIVING_PARAM_8_DEFAULT	(XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT | \
-				 XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)
+#define XTP_LN_TX_LCTXC_SW0_PRE0	GENMASK(5, 0)
+#define XTP_LN_TX_LCTXC_SW0_PRE1	GENMASK(13, 8)
+#define XTP_LN_TX_LCTXC_SW0_PRE2	GENMASK(21, 16)
+#define XTP_LN_TX_LCTXC_SW0_PRE3	GENMASK(29, 24)
+
+#define XTP_LN_TX_LCTXC_SW1_PRE0	GENMASK(5, 0)
+#define XTP_LN_TX_LCTXC_SW1_PRE1	GENMASK(13, 8)
+#define XTP_LN_TX_LCTXC_SW1_PRE2	GENMASK(21, 16)
+#define XTP_LN_TX_LCTXC_SW2_PRE0	GENMASK(29, 24)
+
+#define XTP_LN_TX_LCTXC_SW2_PRE1	GENMASK(5, 0)
+#define XTP_LN_TX_LCTXC_SW3_PRE0	GENMASK(13, 8)
+
+#define BUILD_DRIVING_PARAM_0(sw0_pre0, sw0_pre1, sw0_pre2, sw0_pre3) (	\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW0_PRE0, sw0_pre0) |		\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW0_PRE1, sw0_pre1) |		\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW0_PRE2, sw0_pre2) |		\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW0_PRE3, sw0_pre3)		\
+)
+
+#define BUILD_DRIVING_PARAM_12(sw1_pre0, sw1_pre1, sw1_pre2, sw2_pre0) (\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW1_PRE0, sw1_pre0) |		\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW1_PRE1, sw1_pre1) |		\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW1_PRE2, sw1_pre2) |		\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW2_PRE0, sw2_pre0)		\
+)
+
+#define BUILD_DRIVING_PARAM_23(sw2_pre1, sw3_pre0) (			\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW2_PRE1, sw2_pre1) |		\
+	FIELD_PREP_CONST(XTP_LN_TX_LCTXC_SW3_PRE0, sw3_pre0)		\
+)
+
+/* MT8195: Logic State Change Point (LC TX C) */
+#define MT8195_DRIVING_PARAM_3_DEFAULT	BUILD_DRIVING_PARAM_0( 16, 20, 24, 32)
+#define MT8195_DRIVING_PARAM_4_DEFAULT	BUILD_DRIVING_PARAM_12(24, 30, 36, 32)
+#define MT8195_DRIVING_PARAM_5_DEFAULT	BUILD_DRIVING_PARAM_23(40, 48)
+
+/* MT8195: Positive Edge (LC TX CP) */
+#define MT8195_DRIVING_PARAM_6_DEFAULT	BUILD_DRIVING_PARAM_0( 0, 4, 8, 16)
+#define MT8195_DRIVING_PARAM_7_DEFAULT	BUILD_DRIVING_PARAM_12(0, 6, 12, 0)
+#define MT8195_DRIVING_PARAM_8_DEFAULT	BUILD_DRIVING_PARAM_23(8, 0)
 
 enum mtk_dp_phya_ana_glb_regidx {
 	DP_PHYA_GLB_BIAS_GEN_0,
-- 
2.55.0

[PATCH v4 10/12] phy: phy-mtk-dp: Add bitrate register val definitions to SoC data

[AngeloGioacchino Del Regno]

In preparation for adding support for the eDP PHY found in newer
SoCs, transfer the bitrate register value definitions to SoC
specific data.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 36 +++++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index 8e1fc4e16ba6..643666c454f4 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -44,10 +44,6 @@
 
 /* DP_PHYD_BIT_RATE */
 #define PHYD_DIG_RG_BIT_RATE		GENMASK(1, 0)
-#  define BIT_RATE_RBR			0
-#  define BIT_RATE_HBR			1
-#  define BIT_RATE_HBR2			2
-#  define BIT_RATE_HBR3			3
 
 /* DP_PHYD_SW_RST */
 #define PHYD_DIG_GLB_SW_RST_B		GENMASK(7, 0)
@@ -163,6 +159,14 @@ enum mtk_dp_phyd_dig_glb_regidx {
 	DP_PHYD_GLOBAL_MAX
 };
 
+enum mtk_dp_phyd_bit_rate_regval {
+	DP_PHYD_BIT_RATE_RBR,
+	DP_PHYD_BIT_RATE_HBR,
+	DP_PHYD_BIT_RATE_HBR2,
+	DP_PHYD_BIT_RATE_HBR3,
+	DP_PHYD_BIT_RATE_MAX,
+};
+
 static const u8 mt8195_phy_ana_glb_regs[DP_PHYA_GLOBAL_MAX] = {
 	[DP_PHYA_GLB_BIAS_GEN_0] = 0x0,
 	[DP_PHYA_GLB_BIAS_GEN_1] = 0x4,
@@ -189,6 +193,13 @@ static const u8 mt8195_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] = {
 	[DP_PHYD_TX_CTL_0] = 0x44,
 };
 
+static const u8 mt8195_phy_dig_bitrate_val[DP_PHYD_BIT_RATE_MAX] = {
+	[DP_PHYD_BIT_RATE_RBR] = 0,
+	[DP_PHYD_BIT_RATE_HBR] = 1,
+	[DP_PHYD_BIT_RATE_HBR2] = 2,
+	[DP_PHYD_BIT_RATE_HBR3] = 3
+};
+
 /**
  * struct mtk_dp_phya_imp_sel - Per-Lane Impedance Selection
  * @pmos: Impedance selection for P-Channel MOSFET
@@ -209,6 +220,7 @@ struct mtk_dp_phya_imp_sel {
  * @regs_ana_lane:  Register (layout) offsets for ana_lan
  * @regs_dig_glb:   Register (layout) offsets for dig_glb
  * @regs_dig_lane:  Register (layout) offsets for dig_lan
+ * @val_dig_bitrate:IP Version specific register values for Bit Rate setting
  * @ana_bias_r:     Internal resistance "R" Selection Settings (global)
  * @ana_cktx_imp:   TX Clock Impedance Selection Settings (global)
  * @ana_lanes_imp:  TX Impedance Selection Settings (for all lanes)
@@ -227,6 +239,9 @@ struct mtk_dp_phy_pdata {
 	const u8 *regs_dig_glb;
 	const u8 *regs_dig_lane;
 
+	/* IP-Version specific register value arrays */
+	const u8 *val_dig_bitrate;
+
 	/* Calibration defaults */
 	u8 ana_bias_r;
 	u8 ana_cktx_imp;
@@ -310,6 +325,7 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 
 	if (opts->dp.set_rate) {
 		const u32 reg_bit_rate = pdata->regs_dig_glb[DP_PHYD_BIT_RATE];
+		enum mtk_dp_phyd_bit_rate_regval regval_idx;
 
 		switch (opts->dp.link_rate) {
 		default:
@@ -318,19 +334,20 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 				opts->dp.link_rate);
 			return -EINVAL;
 		case 1620:
-			val = BIT_RATE_RBR;
+			regval_idx = DP_PHYD_BIT_RATE_RBR;
 			break;
 		case 2700:
-			val = BIT_RATE_HBR;
+			regval_idx = DP_PHYD_BIT_RATE_HBR;
 			break;
 		case 5400:
-			val = BIT_RATE_HBR2;
+			regval_idx = DP_PHYD_BIT_RATE_HBR2;
 			break;
 		case 8100:
-			val = BIT_RATE_HBR3;
+			regval_idx = DP_PHYD_BIT_RATE_HBR3;
 			break;
 		}
-		regmap_write(dp_phy->regmap, pdata->off_dig_glb + reg_bit_rate, val);
+		regmap_write(dp_phy->regmap, pdata->off_dig_glb + reg_bit_rate,
+			     pdata->val_dig_bitrate[regval_idx]);
 	}
 
 	if (opts->dp.set_lanes) {
@@ -713,6 +730,7 @@ static const struct mtk_dp_phy_pdata mt8195_dp_phy_data = {
 	.regs_ana_lane = mt8195_phy_ana_lane_regs,
 	.regs_dig_glb = mt8195_phy_dig_glb_regs,
 	.regs_dig_lane = mt8195_phy_dig_lane_regs,
+	.val_dig_bitrate = mt8195_phy_dig_bitrate_val,
 	.ana_bias_r = 15,
 	.ana_cktx_imp = 8,
 	.ana_lanes_imp = {
-- 
2.55.0

[PATCH v4 11/12] phy: phy-mtk-dp: Add PHYD Lane EN register mask to SoC data

[AngeloGioacchino Del Regno]

In preparation for adding support for the eDP PHY found in newer
SoCs, transfer the register mask for PHYD_TX_LN_EN to SoC specific
data.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index 643666c454f4..30f9fa6e6b9b 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -220,6 +220,7 @@ struct mtk_dp_phya_imp_sel {
  * @regs_ana_lane:  Register (layout) offsets for ana_lan
  * @regs_dig_glb:   Register (layout) offsets for dig_glb
  * @regs_dig_lane:  Register (layout) offsets for dig_lan
+ * @mask_dig_tx_ln: Register mask for PHYD_TX_LN_EN field
  * @val_dig_bitrate:IP Version specific register values for Bit Rate setting
  * @ana_bias_r:     Internal resistance "R" Selection Settings (global)
  * @ana_cktx_imp:   TX Clock Impedance Selection Settings (global)
@@ -239,6 +240,9 @@ struct mtk_dp_phy_pdata {
 	const u8 *regs_dig_glb;
 	const u8 *regs_dig_lane;
 
+	/* Register masks */
+	u32 mask_dig_tx_ln;
+
 	/* IP-Version specific register value arrays */
 	const u8 *val_dig_bitrate;
 
@@ -355,10 +359,10 @@ static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
 
 		val = 0;
 		for (i = 0; i < opts->dp.lanes; i++)
-			val |= FIELD_PREP(PHYD_TX_LN_EN, BIT(i));
+			val |= field_prep(pdata->mask_dig_tx_ln, BIT(i));
 
 		regmap_update_bits(dp_phy->regmap, pdata->off_dig_glb + reg_dig_tx_ctl,
-				   PHYD_TX_LN_EN, val);
+				   pdata->mask_dig_tx_ln, val);
 	}
 
 	if (opts->dp.set_voltages) {
@@ -422,7 +426,7 @@ static int mtk_dp_phy_disable_all_lanes(struct mtk_dp_phy *dp_phy)
 
 	/* Get mask of currently enabled lane */
 	regmap_read(dp_phy->regmap, pdata->off_dig_glb + regs[DP_PHYD_TX_CTL_0], &val);
-	val = FIELD_GET(PHYD_TX_LN_EN, val);
+	val = field_get(pdata->mask_dig_tx_ln, val);
 	if (val == 0)
 		return 0;
 
@@ -433,7 +437,7 @@ static int mtk_dp_phy_disable_all_lanes(struct mtk_dp_phy *dp_phy)
 
 		regmap_clear_bits(dp_phy->regmap,
 				  pdata->off_dig_glb + regs[DP_PHYD_TX_CTL_0],
-				  FIELD_PREP(PHYD_TX_LN_EN, BIT(lane_num)));
+				  field_prep(pdata->mask_dig_tx_ln, BIT(lane_num)));
 	} while (val);
 
 	return 0;
@@ -730,6 +734,7 @@ static const struct mtk_dp_phy_pdata mt8195_dp_phy_data = {
 	.regs_ana_lane = mt8195_phy_ana_lane_regs,
 	.regs_dig_glb = mt8195_phy_dig_glb_regs,
 	.regs_dig_lane = mt8195_phy_dig_lane_regs,
+	.mask_dig_tx_ln = PHYD_TX_LN_EN,
 	.val_dig_bitrate = mt8195_phy_dig_bitrate_val,
 	.ana_bias_r = 15,
 	.ana_cktx_imp = 8,
-- 
2.55.0

Re: [PATCH v4 11/12] phy: phy-mtk-dp: Add PHYD Lane EN register mask to SoC data

[Manivannan Sadhasivam]

On Thu, Sep 10, 2026 at 11:20:37AM +0200, AngeloGioacchino Del Regno wrote:
> In preparation for adding support for the eDP PHY found in newer
> SoCs, transfer the register mask for PHYD_TX_LN_EN to SoC specific
> data.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>

- Mani

-- 
மணிவண்ணன் சதாசிவம்

[PATCH v4 12/12] phy: phy-mtk-dp: Add support for MT8196 eDP PHY

[AngeloGioacchino Del Regno]

The MT8196 SoC features an updated PHY IP compared to the older
ones, and there is one that is specific to Embedded DisplayPort.

Add support for the eDP PHY found in the MediaTek MT8196 SoC and
all of its variants.

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 66 ++++++++++++++++++++++++++++++-
 1 file changed, 65 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c b/drivers/phy/mediatek/phy-mtk-dp.c
index 30f9fa6e6b9b..6d06e1c39e3b 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -5,7 +5,7 @@
  * Copyright (c) 2022, BayLibre Inc.
  * Copyright (c) 2022, MediaTek Inc.
  *
- * Major refactoring
+ * Major refactoring and new SoCs support
  * Copyright (c) 2026, Collabora Ltd.
  *                     AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
  */
@@ -43,6 +43,7 @@
 #define TPLL_SSC_EN			BIT(3)
 
 /* DP_PHYD_BIT_RATE */
+#define PHYD_DIG_RG_BIT_RATE_V2		GENMASK(3, 0)
 #define PHYD_DIG_RG_BIT_RATE		GENMASK(1, 0)
 
 /* DP_PHYD_SW_RST */
@@ -63,6 +64,7 @@
 
 /* DP_PHYD_TX_CTL_0 */
 #define PHYD_TX_LN_EN			GENMASK(7, 4)
+#define PHYD_TX_LN_EN_V2		GENMASK(3, 0)
 
 /* DP_PHYD_DRIVING_FORCE */
 #define PHYD_DP_TX_FORCE_VOLT_SWING_EN	BIT(0)
@@ -129,6 +131,16 @@
 #define MT8195_DRIVING_PARAM_7_DEFAULT	BUILD_DRIVING_PARAM_12(0, 6, 12, 0)
 #define MT8195_DRIVING_PARAM_8_DEFAULT	BUILD_DRIVING_PARAM_23(8, 0)
 
+/* MT8196/MT6991: Logic State Change Point (LC TX C) */
+#define MT8196_DRIVING_PARAM_3_DEFAULT	BUILD_DRIVING_PARAM_0( 10, 12, 14, 17)
+#define MT8196_DRIVING_PARAM_4_DEFAULT	BUILD_DRIVING_PARAM_12(14, 17, 18, 18)
+#define MT8196_DRIVING_PARAM_5_DEFAULT	BUILD_DRIVING_PARAM_23(21, 24)
+
+/* MT8196/MT6991: Positive Edge (LC TX CP) */
+#define MT8196_DRIVING_PARAM_6_DEFAULT	BUILD_DRIVING_PARAM_0( 0, 2, 4, 7)
+#define MT8196_DRIVING_PARAM_7_DEFAULT	BUILD_DRIVING_PARAM_12(0, 3, 6, 0)
+#define MT8196_DRIVING_PARAM_8_DEFAULT	BUILD_DRIVING_PARAM_23(3, 0)
+
 enum mtk_dp_phya_ana_glb_regidx {
 	DP_PHYA_GLB_BIAS_GEN_0,
 	DP_PHYA_GLB_BIAS_GEN_1,
@@ -184,6 +196,11 @@ static const u8 mt8195_phy_dig_lane_regs[DP_PHYD_LAN_MAX] = {
 	[DP_PHYD_LAN_DRIVING_PARAM_0] = 0x2c,
 };
 
+static const u8 mt8196_phy_dig_lane_regs[DP_PHYD_LAN_MAX] = {
+	[DP_PHYD_LAN_DRIVING_FORCE] = 0x30,
+	[DP_PHYD_LAN_DRIVING_PARAM_0] = 0x34,
+};
+
 static const u8 mt8195_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] = {
 	[DP_PHYD_PLL_CTL_0] = 0x10,
 	[DP_PHYD_PLL_CTL_1] = 0x14,
@@ -193,6 +210,15 @@ static const u8 mt8195_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] = {
 	[DP_PHYD_TX_CTL_0] = 0x44,
 };
 
+static const u8 mt8196_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] = {
+	[DP_PHYD_PLL_CTL_0] = 0x10,
+	[DP_PHYD_PLL_CTL_1] = 0x14,
+	[DP_PHYD_SW_RST] = 0x38,
+	[DP_PHYD_BIT_RATE] = 0x3c,
+	[DP_PHYD_AUX_RX_CTL] = 0x40,
+	[DP_PHYD_TX_CTL_0] = 0x74,
+};
+
 static const u8 mt8195_phy_dig_bitrate_val[DP_PHYD_BIT_RATE_MAX] = {
 	[DP_PHYD_BIT_RATE_RBR] = 0,
 	[DP_PHYD_BIT_RATE_HBR] = 1,
@@ -200,6 +226,13 @@ static const u8 mt8195_phy_dig_bitrate_val[DP_PHYD_BIT_RATE_MAX] = {
 	[DP_PHYD_BIT_RATE_HBR3] = 3
 };
 
+static const u8 mt8196_edp_phy_dig_bitrate_val[DP_PHYD_BIT_RATE_MAX] = {
+	[DP_PHYD_BIT_RATE_RBR] = 1,
+	[DP_PHYD_BIT_RATE_HBR] = 4,
+	[DP_PHYD_BIT_RATE_HBR2] = 7,
+	[DP_PHYD_BIT_RATE_HBR3] = 9
+};
+
 /**
  * struct mtk_dp_phya_imp_sel - Per-Lane Impedance Selection
  * @pmos: Impedance selection for P-Channel MOSFET
@@ -755,8 +788,39 @@ static const struct mtk_dp_phy_pdata mt8195_dp_phy_data = {
 	},
 };
 
+static const struct mtk_dp_phy_pdata mt8196_edp_phy_data = {
+	.off_ana_glb = 0x400,
+	.off_ana_lane = (const u16[]) { 0x0, 0x100, 0x200, 0x300 },
+	.off_dig_glb = 0x1400,
+	.off_dig_lane = (const u16[]) { 0x1000, 0x1100, 0x1200, 0x1300 },
+	.regs_ana_glb = mt8195_phy_ana_glb_regs,
+	.regs_ana_lane = mt8195_phy_ana_lane_regs,
+	.regs_dig_glb = mt8196_phy_dig_glb_regs,
+	.regs_dig_lane = mt8196_phy_dig_lane_regs,
+	.mask_dig_tx_ln = PHYD_TX_LN_EN_V2,
+	.val_dig_bitrate = mt8196_edp_phy_dig_bitrate_val,
+	.ana_bias_r = 15,
+	.ana_cktx_imp = 8,
+	.ana_lanes_imp = {
+		.pmos = 8,
+		.nmos = 8,
+	},
+	.driving_params = (const u32[]) {
+		[0] = 0,
+		[1] = 0,
+		[2] = 0,
+		[3] = MT8196_DRIVING_PARAM_3_DEFAULT,
+		[4] = MT8196_DRIVING_PARAM_4_DEFAULT,
+		[5] = MT8196_DRIVING_PARAM_5_DEFAULT,
+		[6] = MT8196_DRIVING_PARAM_6_DEFAULT,
+		[7] = MT8196_DRIVING_PARAM_7_DEFAULT,
+		[8] = MT8196_DRIVING_PARAM_8_DEFAULT
+	},
+};
+
 static const struct of_device_id mtk_dp_phy_of_match[] = {
 	{ .compatible = "mediatek,mt8195-dp-phy", .data = &mt8195_dp_phy_data },
+	{ .compatible = "mediatek,mt8196-edp-phy", .data = &mt8196_edp_phy_data },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, mtk_dp_phy_of_match);
-- 
2.55.0

Re: [PATCH v4 00/12] PHY: MediaTek DP PHY refactor and MT8196 eDP

[Vinod Koul]

On Thu, 10 Sep 2026 11:20:26 +0200, AngeloGioacchino Del Regno wrote:
> Changes in v4:
>  - Removed error checking from all regmap_(bulk_){read,write} calls
>    as those are on MMIO and can't fail (Mani)
>  - Changed some of the error prints in mtk_dp_phy_get_one_cal_para()
>    to dev_err_probe() (Mani, Sashiko)
> 
> Changes in v3:
>  - Added missing bitfield.h, pm_runtime.h includes (Sashiko)
>  - Set calibration data before registering PHY (Sashiko)
>  - Enable PM Runtime before creating PHY device (Sashiko)
>  - Continue poweroff if some write fails, but still return failure
>    as that would be a partial poweroff anyway (Sashiko)
>  - Added zero driving params to fix default calibration data setting (Sashiko)
>  - Added NULL check on device_Get_match_data (Sashiko)
> 
> [...]

Applied, thanks!

[01/12] dt-bindings: phy: Document MT8195 and MT8196 DisplayPort PHYs
        commit: 1e432224ed9b31607802ff4e370b73468ca9a452
[02/12] phy: phy-mtk-dp: Rename regs to regmap in struct mtk_dp_phy
        commit: da3c07602f6761403a2ee1b155e7645465c0d36f
[03/12] phy: phy-mtk-dp: Allow probing with devicetree match
        commit: e78be6a5410cf74534be19b3be1090c325132f56
[04/12] phy: phy-mtk-dp: Migrate register offsets to SoC specific pdata
        commit: ae859204b519a384ad0136c21599bab9321090ce
[05/12] phy: phy-mtk-dp: Implement power_on and power_off PHY callbacks
        commit: 10e7b846fc5ed8d3420fc8eb1c0b4524e952b4ac
[06/12] phy: phy-mtk-dp: Support set_lanes in configure and properly cleanup
        commit: 0382b9948627e091aeffcb8be311ea2b26dc1665
[07/12] phy: phy-mtk-dp: Support setting volt swing and preemphasis values
        commit: 283aa3fbbc80e1c1b23264f0bd00a96f5cebbbec
[08/12] phy: phy-mtk-dp: Add support for digital and analog calibration
        commit: 7cf38eb0ab595fc312bef06faedf8a0f0dcb8fcd
[09/12] phy: phy-mtk-dp: Rewrite and document default driving param macros
        commit: 5d907e1bac8a4bf3209fca42ac93c9d2c7f723f8
[10/12] phy: phy-mtk-dp: Add bitrate register val definitions to SoC data
        commit: 53e25169561a500dbcc4992dad17795a11e3e6bf
[11/12] phy: phy-mtk-dp: Add PHYD Lane EN register mask to SoC data
        commit: 09782cc51273ba594905633e1e59ee3c3b82fe6a
[12/12] phy: phy-mtk-dp: Add support for MT8196 eDP PHY
        commit: 6fe4d5beac728b447e77dab158985550ae58718c

Best regards,
-- 
~Vinod