[PATCH v3 0/2] phy: amlogic: Add support for the G12A Analog MIPI D-PHY

[PATCH v3 0/2] phy: amlogic: Add support for the G12A Analog MIPI D-PHY

[Neil Armstrong]

The Amlogic G12A SoCs embeds an Analog MIPI D-PHY to communicate with DSI
panels, this adds the bindings.
    
This Analog D-PHY works with a separate Digital MIPI D-PHY.

This serie adds the Bindings and the PHY driver.

Changes from v2 at [2]:
- Bindings example fix

Changes from v1 at [1]:
- Bindings fixes

[1] https://lore.kernel.org/r/20201123145157.300456-1-narmstrong@baylibre.com
[2] https://lore.kernel.org/r/20210210080736.771803-1-narmstrong@baylibre.com

Neil Armstrong (2):
  dt-bindings: phy: add Amlogic G12A Analog MIPI D-PHY bindings
  phy: amlogic: Add G12A Analog MIPI D-PHY driver

 .../phy/amlogic,g12a-mipi-dphy-analog.yaml    |  35 ++++
 drivers/phy/amlogic/Kconfig                   |  12 ++
 drivers/phy/amlogic/Makefile                  |   1 +
 .../amlogic/phy-meson-g12a-mipi-dphy-analog.c | 177 ++++++++++++++++++
 4 files changed, 225 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/amlogic,g12a-mipi-dphy-analog.yaml
 create mode 100644 drivers/phy/amlogic/phy-meson-g12a-mipi-dphy-analog.c

-- 
2.25.1

[PATCH v3 1/2] dt-bindings: phy: add Amlogic G12A Analog MIPI D-PHY bindings

[Neil Armstrong]

The Amlogic G12A SoCs embeds an Analog MIPI D-PHY to communicate with DSI
panels, this adds the bindings.

This Analog D-PHY works with a separate Digital MIPI D-PHY.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 .../phy/amlogic,g12a-mipi-dphy-analog.yaml    | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/amlogic,g12a-mipi-dphy-analog.yaml

diff --git a/Documentation/devicetree/bindings/phy/amlogic,g12a-mipi-dphy-analog.yaml b/Documentation/devicetree/bindings/phy/amlogic,g12a-mipi-dphy-analog.yaml
new file mode 100644
index 000000000000..7aa0c05d6ce4
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/amlogic,g12a-mipi-dphy-analog.yaml
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/phy/amlogic,g12a-mipi-dphy-analog.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Amlogic G12A MIPI analog PHY
+
+maintainers:
+  - Neil Armstrong <narmstrong@baylibre.com>
+
+properties:
+  compatible:
+    const: amlogic,g12a-mipi-dphy-analog
+
+  "#phy-cells":
+    const: 0
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - "#phy-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    phy@0 {
+          compatible = "amlogic,g12a-mipi-dphy-analog";
+          reg = <0x0 0xc>;
+          #phy-cells = <0>;
+    };
-- 
2.25.1

Re: [PATCH v3 1/2] dt-bindings: phy: add Amlogic G12A Analog MIPI D-PHY bindings

[Martin Blumenstingl]

Hi Neil,

On Fri, Jan 7, 2022 at 4:05 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
[...]
> +required:
> +  - compatible
> +  - reg
> +  - "#phy-cells"
I also found a "MIPI DSI PHY clock" and "MIPI DSI PHY interrupt" in
the datasheet.
I'm no expert on this and I'm just asking in case you have missed one of these:
Can you confirm that these belong to some other IP?


Best regards,
Martin

Re: [PATCH v3 1/2] dt-bindings: phy: add Amlogic G12A Analog MIPI D-PHY bindings

[Neil Armstrong]

On 07/01/2022 23:13, Martin Blumenstingl wrote:
> Hi Neil,
> 
> On Fri, Jan 7, 2022 at 4:05 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
> [...]
>> +required:
>> +  - compatible
>> +  - reg
>> +  - "#phy-cells"
> I also found a "MIPI DSI PHY clock" and "MIPI DSI PHY interrupt" in
> the datasheet.
> I'm no expert on this and I'm just asking in case you have missed one of these:
> Can you confirm that these belong to some other IP?

Indeed the name is misleading, both go to the DSI Transceiver IP (dw-mipi-dsi)

Neil

> 
> 
> Best regards,
> Martin
> 

Re: [PATCH v3 1/2] dt-bindings: phy: add Amlogic G12A Analog MIPI D-PHY bindings

[Martin Blumenstingl]

Hi Neil,

On Mon, Jan 10, 2022 at 10:25 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> On 07/01/2022 23:13, Martin Blumenstingl wrote:
> > Hi Neil,
> >
> > On Fri, Jan 7, 2022 at 4:05 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
> > [...]
> >> +required:
> >> +  - compatible
> >> +  - reg
> >> +  - "#phy-cells"
> > I also found a "MIPI DSI PHY clock" and "MIPI DSI PHY interrupt" in
> > the datasheet.
> > I'm no expert on this and I'm just asking in case you have missed one of these:
> > Can you confirm that these belong to some other IP?
>
> Indeed the name is misleading, both go to the DSI Transceiver IP (dw-mipi-dsi)
Thank you for clarifying this!

I just found an old comment from Rob on v2 of this series: [0]
He mentions:
"If this is a child of something else, then put a $ref to this schema
and the example in the parent schema."

To be honest: I completely forgot about that comment until now.
If I had remembered it (and assuming that his comment is still valid)
then I would have had to NACK my own
Documentation/devicetree/bindings/phy/amlogic,meson8-hdmi-tx-phy.yaml
For today it's already late so I'll look into this more tomorrow.


Best regards,
Martin


[0] https://lore.kernel.org/all/20210210165118.GA2311581@robh.at.kernel.org/

[PATCH v3 2/2] phy: amlogic: Add G12A Analog MIPI D-PHY driver

[Neil Armstrong]

The Amlogic G12A SoCs embeds an Analog MIPI D-PHY used to communicate with DSI
panels.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/phy/amlogic/Kconfig                   |  12 ++
 drivers/phy/amlogic/Makefile                  |   1 +
 .../amlogic/phy-meson-g12a-mipi-dphy-analog.c | 177 ++++++++++++++++++
 3 files changed, 190 insertions(+)
 create mode 100644 drivers/phy/amlogic/phy-meson-g12a-mipi-dphy-analog.c

diff --git a/drivers/phy/amlogic/Kconfig b/drivers/phy/amlogic/Kconfig
index db5d0cd757e3..ac898a102bcc 100644
--- a/drivers/phy/amlogic/Kconfig
+++ b/drivers/phy/amlogic/Kconfig
@@ -49,6 +49,18 @@ config PHY_MESON_G12A_USB3_PCIE
 	  in Meson G12A SoCs.
 	  If unsure, say N.
 
+config PHY_MESON_G12A_MIPI_DPHY_ANALOG
+	tristate "Meson G12A MIPI Analog DPHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	select GENERIC_PHY_MIPI_DPHY
+	help
+	  Enable this to support the Meson MIPI Analog DPHY found in Meson G12A
+	  SoCs.
+	  If unsure, say N.
+
 config PHY_MESON_AXG_PCIE
 	tristate "Meson AXG PCIE PHY driver"
 	default ARCH_MESON
diff --git a/drivers/phy/amlogic/Makefile b/drivers/phy/amlogic/Makefile
index 8fa07fbd0d92..2eada0a683ca 100644
--- a/drivers/phy/amlogic/Makefile
+++ b/drivers/phy/amlogic/Makefile
@@ -3,6 +3,7 @@ obj-$(CONFIG_PHY_MESON8B_USB2)			+= phy-meson8b-usb2.o
 obj-$(CONFIG_PHY_MESON_GXL_USB2)		+= phy-meson-gxl-usb2.o
 obj-$(CONFIG_PHY_MESON_G12A_USB2)		+= phy-meson-g12a-usb2.o
 obj-$(CONFIG_PHY_MESON_G12A_USB3_PCIE)		+= phy-meson-g12a-usb3-pcie.o
+obj-$(CONFIG_PHY_MESON_G12A_MIPI_DPHY_ANALOG)	+= phy-meson-g12a-mipi-dphy-analog.o
 obj-$(CONFIG_PHY_MESON_AXG_PCIE)		+= phy-meson-axg-pcie.o
 obj-$(CONFIG_PHY_MESON_AXG_MIPI_PCIE_ANALOG)	+= phy-meson-axg-mipi-pcie-analog.o
 obj-$(CONFIG_PHY_MESON_AXG_MIPI_DPHY)		+= phy-meson-axg-mipi-dphy.o
diff --git a/drivers/phy/amlogic/phy-meson-g12a-mipi-dphy-analog.c b/drivers/phy/amlogic/phy-meson-g12a-mipi-dphy-analog.c
new file mode 100644
index 000000000000..6e9d416c0552
--- /dev/null
+++ b/drivers/phy/amlogic/phy-meson-g12a-mipi-dphy-analog.c
@@ -0,0 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Meson G12A MIPI DSI Analog PHY
+ *
+ * Copyright (C) 2018 Amlogic, Inc. All rights reserved
+ * Copyright (C) 2020 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ */
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/phy/phy.h>
+
+#define HHI_MIPI_CNTL0 0x00
+#define		HHI_MIPI_CNTL0_DIF_REF_CTL1	GENMASK(31, 16)
+#define		HHI_MIPI_CNTL0_DIF_REF_CTL0	GENMASK(15, 0)
+
+#define HHI_MIPI_CNTL1 0x04
+#define		HHI_MIPI_CNTL1_BANDGAP		BIT(16)
+#define		HHI_MIPI_CNTL2_DIF_REF_CTL2	GENMASK(15, 0)
+
+#define HHI_MIPI_CNTL2 0x08
+#define		HHI_MIPI_CNTL2_DIF_TX_CTL1	GENMASK(31, 16)
+#define		HHI_MIPI_CNTL2_CH_EN		GENMASK(15, 11)
+#define		HHI_MIPI_CNTL2_DIF_TX_CTL0	GENMASK(10, 0)
+
+#define DSI_LANE_0				BIT(4)
+#define DSI_LANE_1				BIT(3)
+#define DSI_LANE_CLK				BIT(2)
+#define DSI_LANE_2				BIT(1)
+#define DSI_LANE_3				BIT(0)
+
+struct phy_g12a_mipi_dphy_analog_priv {
+	struct phy *phy;
+	struct regmap *regmap;
+	struct phy_configure_opts_mipi_dphy config;
+};
+
+static int phy_g12a_mipi_dphy_analog_configure(struct phy *phy,
+					       union phy_configure_opts *opts)
+{
+	struct phy_g12a_mipi_dphy_analog_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = phy_mipi_dphy_config_validate(&opts->mipi_dphy);
+	if (ret)
+		return ret;
+
+	memcpy(&priv->config, opts, sizeof(priv->config));
+
+	return 0;
+}
+
+static int phy_g12a_mipi_dphy_analog_power_on(struct phy *phy)
+{
+	struct phy_g12a_mipi_dphy_analog_priv *priv = phy_get_drvdata(phy);
+	unsigned int reg;
+
+	regmap_write(priv->regmap, HHI_MIPI_CNTL0,
+		     FIELD_PREP(HHI_MIPI_CNTL0_DIF_REF_CTL0, 0x8) |
+		     FIELD_PREP(HHI_MIPI_CNTL0_DIF_REF_CTL1, 0xa487));
+
+	regmap_write(priv->regmap, HHI_MIPI_CNTL1,
+		     FIELD_PREP(HHI_MIPI_CNTL2_DIF_REF_CTL2, 0x2e) |
+		     HHI_MIPI_CNTL1_BANDGAP);
+
+	regmap_write(priv->regmap, HHI_MIPI_CNTL2,
+		     FIELD_PREP(HHI_MIPI_CNTL2_DIF_TX_CTL0, 0x459) |
+		     FIELD_PREP(HHI_MIPI_CNTL2_DIF_TX_CTL1, 0x2680));
+
+	reg = DSI_LANE_CLK;
+	switch (priv->config.lanes) {
+	case 4:
+		reg |= DSI_LANE_3;
+		fallthrough;
+	case 3:
+		reg |= DSI_LANE_2;
+		fallthrough;
+	case 2:
+		reg |= DSI_LANE_1;
+		fallthrough;
+	case 1:
+		reg |= DSI_LANE_0;
+		break;
+	default:
+		reg = 0;
+	}
+
+	regmap_update_bits(priv->regmap, HHI_MIPI_CNTL2,
+			   HHI_MIPI_CNTL2_CH_EN,
+			   FIELD_PREP(HHI_MIPI_CNTL2_CH_EN, reg));
+
+	return 0;
+}
+
+static int phy_g12a_mipi_dphy_analog_power_off(struct phy *phy)
+{
+	struct phy_g12a_mipi_dphy_analog_priv *priv = phy_get_drvdata(phy);
+
+	regmap_write(priv->regmap, HHI_MIPI_CNTL0, 0);
+	regmap_write(priv->regmap, HHI_MIPI_CNTL1, 0);
+	regmap_write(priv->regmap, HHI_MIPI_CNTL2, 0);
+
+	return 0;
+}
+
+static const struct phy_ops phy_g12a_mipi_dphy_analog_ops = {
+	.configure = phy_g12a_mipi_dphy_analog_configure,
+	.power_on = phy_g12a_mipi_dphy_analog_power_on,
+	.power_off = phy_g12a_mipi_dphy_analog_power_off,
+	.owner = THIS_MODULE,
+};
+
+static int phy_g12a_mipi_dphy_analog_probe(struct platform_device *pdev)
+{
+	struct phy_provider *phy;
+	struct device *dev = &pdev->dev;
+	struct phy_g12a_mipi_dphy_analog_priv *priv;
+	struct device_node *np = dev->of_node;
+	struct regmap *map;
+	int ret;
+
+	priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	/* Get the hhi system controller node */
+	map = syscon_node_to_regmap(of_get_parent(dev->of_node));
+	if (IS_ERR(map)) {
+		dev_err(dev,
+			"failed to get HHI regmap\n");
+		return PTR_ERR(map);
+	}
+
+	priv->regmap = map;
+
+	priv->phy = devm_phy_create(dev, np, &phy_g12a_mipi_dphy_analog_ops);
+	if (IS_ERR(priv->phy)) {
+		ret = PTR_ERR(priv->phy);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "failed to create PHY\n");
+		return ret;
+	}
+
+	phy_set_drvdata(priv->phy, priv);
+	dev_set_drvdata(dev, priv);
+
+	phy = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy);
+}
+
+static const struct of_device_id phy_g12a_mipi_dphy_analog_of_match[] = {
+	{
+		.compatible = "amlogic,g12a-mipi-dphy-analog",
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, phy_g12a_mipi_dphy_analog_of_match);
+
+static struct platform_driver phy_g12a_mipi_dphy_analog_driver = {
+	.probe = phy_g12a_mipi_dphy_analog_probe,
+	.driver = {
+		.name = "phy-meson-g12a-mipi-dphy-analog",
+		.of_match_table = phy_g12a_mipi_dphy_analog_of_match,
+	},
+};
+module_platform_driver(phy_g12a_mipi_dphy_analog_driver);
+
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_DESCRIPTION("Meson G12A MIPI Analog D-PHY driver");
+MODULE_LICENSE("GPL v2");
-- 
2.25.1

Re: [PATCH v3 2/2] phy: amlogic: Add G12A Analog MIPI D-PHY driver

[Martin Blumenstingl]

Hi Neil,

On Fri, Jan 7, 2022 at 4:06 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
[...]
> +#define HHI_MIPI_CNTL2 0x08
> +#define                HHI_MIPI_CNTL2_DIF_TX_CTL1      GENMASK(31, 16)
> +#define                HHI_MIPI_CNTL2_CH_EN            GENMASK(15, 11)
> +#define                HHI_MIPI_CNTL2_DIF_TX_CTL0      GENMASK(10, 0)
> +
> +#define DSI_LANE_0                             BIT(4)
> +#define DSI_LANE_1                             BIT(3)
> +#define DSI_LANE_CLK                           BIT(2)
> +#define DSI_LANE_2                             BIT(1)
> +#define DSI_LANE_3                             BIT(0)
At first I thought that these should be named
HHI_MIPI_CNTL2_DSI_LANE_0 (and similar).
But then I understood that they aren't bits directly in HHI_MIPI_CNTL2
but they belong to HHI_MIPI_CNTL2_CH_EN.
Have you considered naming them for example
HHI_MIPI_CNTL2_CH_EN_DSI_LANE_0 to make this more clear?

[...]
> +       if (IS_ERR(map)) {
> +               dev_err(dev,
> +                       "failed to get HHI regmap\n");
> +               return PTR_ERR(map);
I suggest using:
  return dev_err_probe(dev, PTR_ERR(map), "failed to get HHI regmap\n");
to simplify the code

[...]
> +       if (IS_ERR(priv->phy)) {
> +               ret = PTR_ERR(priv->phy);
> +               if (ret != -EPROBE_DEFER)
> +                       dev_err(dev, "failed to create PHY\n");
> +               return ret;
and similar here:
  return dev_err_probe(dev, PTR_ERR(priv->phy), "failed to create PHY\n");

[...]
> +static const struct of_device_id phy_g12a_mipi_dphy_analog_of_match[] = {
> +       {
> +               .compatible = "amlogic,g12a-mipi-dphy-analog",
> +       },
> +       { },
In the past I was suggested to use:
  { /* sentinel */ }
meaning: no trailing comma here so nobody can add entries after the
sentinel by accident.
I suggest doing the same here if you re-spin this series.


Thank you!
Martin

Re: [PATCH v3 2/2] phy: amlogic: Add G12A Analog MIPI D-PHY driver

[Neil Armstrong]

Hi,

On 07/01/2022 23:09, Martin Blumenstingl wrote:
> Hi Neil,
> 
> On Fri, Jan 7, 2022 at 4:06 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
> [...]
>> +#define HHI_MIPI_CNTL2 0x08
>> +#define                HHI_MIPI_CNTL2_DIF_TX_CTL1      GENMASK(31, 16)
>> +#define                HHI_MIPI_CNTL2_CH_EN            GENMASK(15, 11)
>> +#define                HHI_MIPI_CNTL2_DIF_TX_CTL0      GENMASK(10, 0)
>> +
>> +#define DSI_LANE_0                             BIT(4)
>> +#define DSI_LANE_1                             BIT(3)
>> +#define DSI_LANE_CLK                           BIT(2)
>> +#define DSI_LANE_2                             BIT(1)
>> +#define DSI_LANE_3                             BIT(0)
> At first I thought that these should be named
> HHI_MIPI_CNTL2_DSI_LANE_0 (and similar).
> But then I understood that they aren't bits directly in HHI_MIPI_CNTL2
> but they belong to HHI_MIPI_CNTL2_CH_EN.
> Have you considered naming them for example
> HHI_MIPI_CNTL2_CH_EN_DSI_LANE_0 to make this more clear?
> 
> [...]
>> +       if (IS_ERR(map)) {
>> +               dev_err(dev,
>> +                       "failed to get HHI regmap\n");
>> +               return PTR_ERR(map);
> I suggest using:
>   return dev_err_probe(dev, PTR_ERR(map), "failed to get HHI regmap\n");
> to simplify the code
> 
> [...]
>> +       if (IS_ERR(priv->phy)) {
>> +               ret = PTR_ERR(priv->phy);
>> +               if (ret != -EPROBE_DEFER)
>> +                       dev_err(dev, "failed to create PHY\n");
>> +               return ret;
> and similar here:
>   return dev_err_probe(dev, PTR_ERR(priv->phy), "failed to create PHY\n");
> 
> [...]
>> +static const struct of_device_id phy_g12a_mipi_dphy_analog_of_match[] = {
>> +       {
>> +               .compatible = "amlogic,g12a-mipi-dphy-analog",
>> +       },
>> +       { },
> In the past I was suggested to use:
>   { /* sentinel */ }
> meaning: no trailing comma here so nobody can add entries after the
> sentinel by accident.
> I suggest doing the same here if you re-spin this series.

Yep, will do the changes,

Thanks,
Neil

> 
> 
> Thank you!
> Martin
>