phy: amlogic: Add G12A Analog MIPI D-PHY driver

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

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20220705075650.3165348-3-narmstrong@baylibre.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/amlogic/Kconfig

@@ -37,6 +37,18 @@ config PHY_MESON_GXL_USB2
 	  GXL and GXM 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 MFD_SYSCON
+	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_G12A_USB2
 	tristate "Meson G12A USB2 PHY driver"
 	default ARCH_MESON

drivers/phy/amlogic/Makefile

@@ -4,6 +4,7 @@ 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

drivers/phy/amlogic/phy-meson-g12a-mipi-dphy-analog.c

@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Meson G12A MIPI DSI Analog PHY
+ *
+ * Copyright (C) 2018 Amlogic, Inc. All rights reserved
+ * Copyright (C) 2022 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, *parent_np;
+	struct regmap *map;
+
+	priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	/* Get the hhi system controller node */
+	parent_np = of_get_parent(np);
+	map = syscon_node_to_regmap(parent_np);
+	of_node_put(parent_np);
+	if (IS_ERR(map))
+		return dev_err_probe(dev, PTR_ERR(map), "failed to get HHI regmap\n");
+
+	priv->regmap = map;
+
+	priv->phy = devm_phy_create(dev, np, &phy_g12a_mipi_dphy_analog_ops);
+	if (IS_ERR(priv->phy))
+		return dev_err_probe(dev, PTR_ERR(priv->phy), "failed to create PHY\n");
+
+	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",
+	},
+	{ /* sentinel */ }
+};
+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");