phy: amlogic: Add Amlogic AXG MIPI/PCIE analog PHY Driver

This adds support for the MIPI analog PHY which is also used for PCIE
found in the Amlogic AXG SoC Family.

MIPI or PCIE selection is done by the #phy-cells, making the mode
static and exclusive.

For now only PCIE functionality is supported.

This PHY will be used to replace the mipi_enable clock gating logic
which was mistakenly added in the clock subsystem. This also activates
a non documented band gap bit in those registers that allows reliable
PCIE clock signal generation on AXG platforms.

Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>

3 files changed, 205 insertions, 5 deletions

diff --git a/drivers/phy/amlogic/Kconfig b/drivers/phy/amlogic/Kconfig
index af774ac2b934..8c9cf2403591 100644
--- a/drivers/phy/amlogic/Kconfig
+++ b/drivers/phy/amlogic/Kconfig
@@ -59,3 +59,14 @@ config PHY_MESON_G12A_USB3_PCIE
 	  Enable this to support the Meson USB3 + PCIE Combo PHY found
 	  in Meson G12A SoCs.
 	  If unsure, say N.
+
+config PHY_MESON_AXG_MIPI_PCIE_ANALOG
+	tristate "Meson AXG MIPI + PCIE analog PHY driver"
+	default ARCH_MESON
+	depends on OF && (ARCH_MESON || COMPILE_TEST)
+	select GENERIC_PHY
+	select REGMAP_MMIO
+	help
+	  Enable this to support the Meson MIPI + PCIE analog PHY
+	  found in Meson AXG SoCs.
+	  If unsure, say N.
diff --git a/drivers/phy/amlogic/Makefile b/drivers/phy/amlogic/Makefile
index 11d1c42ac2be..0aecf92d796a 100644
--- a/drivers/phy/amlogic/Makefile
+++ b/drivers/phy/amlogic/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
-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_GXL_USB3)	+= phy-meson-gxl-usb3.o
-obj-$(CONFIG_PHY_MESON_G12A_USB3_PCIE)	+= phy-meson-g12a-usb3-pcie.o
+obj-$(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-$(CONFIG_PHY_MESON_GXL_USB3)		+= phy-meson-gxl-usb3.o
+obj-$(CONFIG_PHY_MESON_G12A_USB3_PCIE)		+= phy-meson-g12a-usb3-pcie.o
+obj-$(CONFIG_PHY_MESON_AXG_MIPI_PCIE_ANALOG)	+= phy-meson-axg-mipi-pcie-analog.o
diff --git a/drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c b/drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c
new file mode 100644
index 000000000000..1431cbf885e1
--- /dev/null
+++ b/drivers/phy/amlogic/phy-meson-axg-mipi-pcie-analog.c
@@ -0,0 +1,188 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Amlogic AXG MIPI + PCIE analog PHY driver
+ *
+ * Copyright (C) 2019 Remi Pommarel <repk@triplefau.lt>
+ */
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/phy/phy.h>
+
+#define HHI_MIPI_CNTL0 0x00
+#define		HHI_MIPI_CNTL0_COMMON_BLOCK	GENMASK(31, 28)
+#define		HHI_MIPI_CNTL0_ENABLE		BIT(29)
+#define		HHI_MIPI_CNTL0_BANDGAP		BIT(26)
+#define		HHI_MIPI_CNTL0_DECODE_TO_RTERM	GENMASK(15, 12)
+#define		HHI_MIPI_CNTL0_OUTPUT_EN	BIT(3)
+
+#define HHI_MIPI_CNTL1 0x01
+#define		HHI_MIPI_CNTL1_CH0_CML_PDR_EN	BIT(12)
+#define		HHI_MIPI_CNTL1_LP_ABILITY	GENMASK(5, 4)
+#define		HHI_MIPI_CNTL1_LP_RESISTER	BIT(3)
+#define		HHI_MIPI_CNTL1_INPUT_SETTING	BIT(2)
+#define		HHI_MIPI_CNTL1_INPUT_SEL	BIT(1)
+#define		HHI_MIPI_CNTL1_PRBS7_EN		BIT(0)
+
+#define HHI_MIPI_CNTL2 0x02
+#define		HHI_MIPI_CNTL2_CH_PU		GENMASK(31, 25)
+#define		HHI_MIPI_CNTL2_CH_CTL		GENMASK(24, 19)
+#define		HHI_MIPI_CNTL2_CH0_DIGDR_EN	BIT(18)
+#define		HHI_MIPI_CNTL2_CH_DIGDR_EN	BIT(17)
+#define		HHI_MIPI_CNTL2_LPULPS_EN	BIT(16)
+#define		HHI_MIPI_CNTL2_CH_EN(n)		BIT(15 - (n))
+#define		HHI_MIPI_CNTL2_CH0_LP_CTL	GENMASK(10, 1)
+
+struct phy_axg_mipi_pcie_analog_priv {
+	struct phy *phy;
+	unsigned int mode;
+	struct regmap *regmap;
+};
+
+static const struct regmap_config phy_axg_mipi_pcie_analog_regmap_conf = {
+	.reg_bits = 8,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = HHI_MIPI_CNTL2,
+};
+
+static int phy_axg_mipi_pcie_analog_power_on(struct phy *phy)
+{
+	struct phy_axg_mipi_pcie_analog_priv *priv = phy_get_drvdata(phy);
+
+	/* MIPI not supported yet */
+	if (priv->mode != PHY_TYPE_PCIE)
+		return -EINVAL;
+
+	regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
+			   HHI_MIPI_CNTL0_BANDGAP, HHI_MIPI_CNTL0_BANDGAP);
+
+	regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
+			   HHI_MIPI_CNTL0_ENABLE, HHI_MIPI_CNTL0_ENABLE);
+	return 0;
+}
+
+static int phy_axg_mipi_pcie_analog_power_off(struct phy *phy)
+{
+	struct phy_axg_mipi_pcie_analog_priv *priv = phy_get_drvdata(phy);
+
+	/* MIPI not supported yet */
+	if (priv->mode != PHY_TYPE_PCIE)
+		return -EINVAL;
+
+	regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
+			   HHI_MIPI_CNTL0_BANDGAP, 0);
+	regmap_update_bits(priv->regmap, HHI_MIPI_CNTL0,
+			   HHI_MIPI_CNTL0_ENABLE, 0);
+	return 0;
+}
+
+static int phy_axg_mipi_pcie_analog_init(struct phy *phy)
+{
+	return 0;
+}
+
+static int phy_axg_mipi_pcie_analog_exit(struct phy *phy)
+{
+	return 0;
+}
+
+static const struct phy_ops phy_axg_mipi_pcie_analog_ops = {
+	.init = phy_axg_mipi_pcie_analog_init,
+	.exit = phy_axg_mipi_pcie_analog_exit,
+	.power_on = phy_axg_mipi_pcie_analog_power_on,
+	.power_off = phy_axg_mipi_pcie_analog_power_off,
+	.owner = THIS_MODULE,
+};
+
+static struct phy *phy_axg_mipi_pcie_analog_xlate(struct device *dev,
+						  struct of_phandle_args *args)
+{
+	struct phy_axg_mipi_pcie_analog_priv *priv = dev_get_drvdata(dev);
+	unsigned int mode;
+
+	if (args->args_count != 1) {
+		dev_err(dev, "invalid number of arguments\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	mode = args->args[0];
+
+	/* MIPI mode is not supported yet */
+	if (mode != PHY_TYPE_PCIE) {
+		dev_err(dev, "invalid phy mode select argument\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	priv->mode = mode;
+	return priv->phy;
+}
+
+static int phy_axg_mipi_pcie_analog_probe(struct platform_device *pdev)
+{
+	struct phy_provider *phy;
+	struct device *dev = &pdev->dev;
+	struct phy_axg_mipi_pcie_analog_priv *priv;
+	struct device_node *np = dev->of_node;
+	struct regmap *map;
+	struct resource *res;
+	void __iomem *base;
+	int ret;
+
+	priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base)) {
+		dev_err(dev, "failed to get regmap base\n");
+		return PTR_ERR(base);
+	}
+
+	map = devm_regmap_init_mmio(dev, base,
+				    &phy_axg_mipi_pcie_analog_regmap_conf);
+	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_axg_mipi_pcie_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,
+					    phy_axg_mipi_pcie_analog_xlate);
+
+	return PTR_ERR_OR_ZERO(phy);
+}
+
+static const struct of_device_id phy_axg_mipi_pcie_analog_of_match[] = {
+	{
+		.compatible = "amlogic,axg-mipi-pcie-analog-phy",
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, phy_axg_mipi_pcie_analog_of_match);
+
+static struct platform_driver phy_axg_mipi_pcie_analog_driver = {
+	.probe = phy_axg_mipi_pcie_analog_probe,
+	.driver = {
+		.name = "phy-axg-mipi-pcie-analog",
+		.of_match_table = phy_axg_mipi_pcie_analog_of_match,
+	},
+};
+module_platform_driver(phy_axg_mipi_pcie_analog_driver);
+
+MODULE_AUTHOR("Remi Pommarel <repk@triplefau.lt>");
+MODULE_DESCRIPTION("Amlogic AXG MIPI + PCIE analog PHY driver");
+MODULE_LICENSE("GPL v2");