phy: mtk-mipi-csi: add driver for CSI phy

This is a new driver that supports the MIPI CSI CD-PHY version 0.5

The number of PHYs depend on the SoC.
Each PHY can support D-PHY only or CD-PHY configuration.
The driver supports only D-PHY mode, so CD-PHY
compatible PHY are configured in D-PHY mode.

[Julien Stephan: simplify driver model: one instance per phy vs
one instance for all phys]

Signed-off-by: Louis Kuo <louis.kuo@mediatek.com>
Signed-off-by: Phi-bang Nguyen <pnguyen@baylibre.com>
[Julien Stephan: refactor code]
Co-developed-by: Julien Stephan <jstephan@baylibre.com>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240111101738.468916-1-jstephan@baylibre.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

4 files changed, 370 insertions, 0 deletions

diff --git a/drivers/phy/mediatek/Kconfig b/drivers/phy/mediatek/Kconfig
index 3125ecb5d119..3849b7c87d28 100644
--- a/drivers/phy/mediatek/Kconfig
+++ b/drivers/phy/mediatek/Kconfig
@@ -58,6 +58,18 @@ config PHY_MTK_HDMI
 	help
 	  Support HDMI PHY for Mediatek SoCs.
 
+config PHY_MTK_MIPI_CSI_0_5
+	tristate "MediaTek MIPI CSI CD-PHY v0.5 Driver"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	depends on OF
+	select GENERIC_PHY
+	help
+	  Enable this to support the MIPI CSI CD-PHY receiver version 0.5.
+	  The driver supports multiple CSI cdphy ports simultaneously.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called phy-mtk-mipi-csi-0-5.
+
 config PHY_MTK_MIPI_DSI
 	tristate "MediaTek MIPI-DSI Driver"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
diff --git a/drivers/phy/mediatek/Makefile b/drivers/phy/mediatek/Makefile
index c9a50395533e..f6e24a47e081 100644
--- a/drivers/phy/mediatek/Makefile
+++ b/drivers/phy/mediatek/Makefile
@@ -15,6 +15,8 @@ phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt8173.o
 phy-mtk-hdmi-drv-y			+= phy-mtk-hdmi-mt8195.o
 obj-$(CONFIG_PHY_MTK_HDMI)		+= phy-mtk-hdmi-drv.o
 
+obj-$(CONFIG_PHY_MTK_MIPI_CSI_0_5)	+= phy-mtk-mipi-csi-0-5.o
+
 phy-mtk-mipi-dsi-drv-y			:= phy-mtk-mipi-dsi.o
 phy-mtk-mipi-dsi-drv-y			+= phy-mtk-mipi-dsi-mt8173.o
 phy-mtk-mipi-dsi-drv-y			+= phy-mtk-mipi-dsi-mt8183.o
diff --git a/drivers/phy/mediatek/phy-mtk-mipi-csi-0-5-rx-reg.h b/drivers/phy/mediatek/phy-mtk-mipi-csi-0-5-rx-reg.h
new file mode 100644
index 000000000000..97b4c27a1699
--- /dev/null
+++ b/drivers/phy/mediatek/phy-mtk-mipi-csi-0-5-rx-reg.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2023, MediaTek Inc.
+ * Copyright (c) 2023, BayLibre Inc.
+ */
+
+#ifndef __PHY_MTK_MIPI_CSI_V_0_5_RX_REG_H__
+#define __PHY_MTK_MIPI_CSI_V_0_5_RX_REG_H__
+
+/*
+ * CSI1 and CSI2 are identical, and similar to CSI0. All CSIX macros are
+ * applicable to the three PHYs. Where differences exist, they are denoted by
+ * macro names using CSI0 and CSI1, the latter being applicable to CSI1 and
+ * CSI2 alike.
+ */
+
+#define MIPI_RX_ANA00_CSIXA			0x0000
+#define RG_CSI0A_CPHY_EN			BIT(0)
+#define RG_CSIXA_EQ_PROTECT_EN			BIT(1)
+#define RG_CSIXA_BG_LPF_EN			BIT(2)
+#define RG_CSIXA_BG_CORE_EN			BIT(3)
+#define RG_CSIXA_DPHY_L0_CKMODE_EN		BIT(5)
+#define RG_CSIXA_DPHY_L0_CKSEL			BIT(6)
+#define RG_CSIXA_DPHY_L1_CKMODE_EN		BIT(8)
+#define RG_CSIXA_DPHY_L1_CKSEL			BIT(9)
+#define RG_CSIXA_DPHY_L2_CKMODE_EN		BIT(11)
+#define RG_CSIXA_DPHY_L2_CKSEL			BIT(12)
+
+#define MIPI_RX_ANA18_CSIXA			0x0018
+#define RG_CSI0A_L0_T0AB_EQ_IS			GENMASK(5, 4)
+#define RG_CSI0A_L0_T0AB_EQ_BW			GENMASK(7, 6)
+#define RG_CSI0A_L1_T1AB_EQ_IS			GENMASK(21, 20)
+#define RG_CSI0A_L1_T1AB_EQ_BW			GENMASK(23, 22)
+#define RG_CSI0A_L2_T1BC_EQ_IS			GENMASK(21, 20)
+#define RG_CSI0A_L2_T1BC_EQ_BW			GENMASK(23, 22)
+#define RG_CSI1A_L0_EQ_IS			GENMASK(5, 4)
+#define RG_CSI1A_L0_EQ_BW			GENMASK(7, 6)
+#define RG_CSI1A_L1_EQ_IS			GENMASK(21, 20)
+#define RG_CSI1A_L1_EQ_BW			GENMASK(23, 22)
+#define RG_CSI1A_L2_EQ_IS			GENMASK(5, 4)
+#define RG_CSI1A_L2_EQ_BW			GENMASK(7, 6)
+
+#define MIPI_RX_ANA1C_CSIXA			0x001c
+#define MIPI_RX_ANA20_CSI0A			0x0020
+
+#define MIPI_RX_ANA24_CSIXA			0x0024
+#define RG_CSIXA_RESERVE			GENMASK(31, 24)
+
+#define MIPI_RX_ANA40_CSIXA			0x0040
+#define RG_CSIXA_CPHY_FMCK_SEL			GENMASK(1, 0)
+#define RG_CSIXA_ASYNC_OPTION			GENMASK(7, 4)
+#define RG_CSIXA_CPHY_SPARE			GENMASK(31, 16)
+
+#define MIPI_RX_WRAPPER80_CSIXA			0x0080
+#define CSR_CSI_RST_MODE			GENMASK(17, 16)
+
+#define MIPI_RX_ANAA8_CSIXA			0x00a8
+#define RG_CSIXA_CDPHY_L0_T0_BYTECK_INVERT	BIT(0)
+#define RG_CSIXA_DPHY_L1_BYTECK_INVERT		BIT(1)
+#define RG_CSIXA_CDPHY_L2_T1_BYTECK_INVERT	BIT(2)
+
+#endif
diff --git a/drivers/phy/mediatek/phy-mtk-mipi-csi-0-5.c b/drivers/phy/mediatek/phy-mtk-mipi-csi-0-5.c
new file mode 100644
index 000000000000..972c129185f7
--- /dev/null
+++ b/drivers/phy/mediatek/phy-mtk-mipi-csi-0-5.c
@@ -0,0 +1,294 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MediaTek MIPI CSI v0.5 driver
+ *
+ * Copyright (c) 2023, MediaTek Inc.
+ * Copyright (c) 2023, BayLibre Inc.
+ */
+
+#include <dt-bindings/phy/phy.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "phy-mtk-io.h"
+#include "phy-mtk-mipi-csi-0-5-rx-reg.h"
+
+#define CSIXB_OFFSET		0x1000
+
+struct mtk_mipi_cdphy_port {
+	struct device *dev;
+	void __iomem *base;
+	struct phy *phy;
+	u32 type;
+	u32 mode;
+	u32 num_lanes;
+};
+
+enum PHY_TYPE {
+	DPHY = 0,
+	CPHY,
+	CDPHY,
+};
+
+static void mtk_phy_csi_cdphy_ana_eq_tune(void __iomem *base)
+{
+	mtk_phy_update_field(base + MIPI_RX_ANA18_CSIXA, RG_CSI0A_L0_T0AB_EQ_IS, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA18_CSIXA, RG_CSI0A_L0_T0AB_EQ_BW, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA1C_CSIXA, RG_CSI0A_L1_T1AB_EQ_IS, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA1C_CSIXA, RG_CSI0A_L1_T1AB_EQ_BW, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA20_CSI0A, RG_CSI0A_L2_T1BC_EQ_IS, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA20_CSI0A, RG_CSI0A_L2_T1BC_EQ_BW, 1);
+
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA18_CSIXA, RG_CSI0A_L0_T0AB_EQ_IS, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA18_CSIXA, RG_CSI0A_L0_T0AB_EQ_BW, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA1C_CSIXA, RG_CSI0A_L1_T1AB_EQ_IS, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA1C_CSIXA, RG_CSI0A_L1_T1AB_EQ_BW, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA20_CSI0A, RG_CSI0A_L2_T1BC_EQ_IS, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA20_CSI0A, RG_CSI0A_L2_T1BC_EQ_BW, 1);
+}
+
+static void mtk_phy_csi_dphy_ana_eq_tune(void __iomem *base)
+{
+	mtk_phy_update_field(base + MIPI_RX_ANA18_CSIXA, RG_CSI1A_L0_EQ_IS, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA18_CSIXA, RG_CSI1A_L0_EQ_BW, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA18_CSIXA, RG_CSI1A_L1_EQ_IS, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA18_CSIXA, RG_CSI1A_L1_EQ_BW, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA1C_CSIXA, RG_CSI1A_L2_EQ_IS, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA1C_CSIXA, RG_CSI1A_L2_EQ_BW, 1);
+
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA18_CSIXA, RG_CSI1A_L0_EQ_IS, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA18_CSIXA, RG_CSI1A_L0_EQ_BW, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA18_CSIXA, RG_CSI1A_L1_EQ_IS, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA18_CSIXA, RG_CSI1A_L1_EQ_BW, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA1C_CSIXA, RG_CSI1A_L2_EQ_IS, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA1C_CSIXA, RG_CSI1A_L2_EQ_BW, 1);
+}
+
+static int mtk_mipi_phy_power_on(struct phy *phy)
+{
+	struct mtk_mipi_cdphy_port *port = phy_get_drvdata(phy);
+	void __iomem *base = port->base;
+
+	/*
+	 * The driver currently supports DPHY and CD-PHY phys,
+	 * but the only mode supported is DPHY,
+	 * so CD-PHY capable phys must be configured in DPHY mode
+	 */
+	if (port->type == CDPHY) {
+		mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSI0A_CPHY_EN, 0);
+		mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA,
+				     RG_CSI0A_CPHY_EN, 0);
+	}
+
+	/*
+	 * Lane configuration:
+	 *
+	 * Only 4 data + 1 clock is supported for now with the following mapping:
+	 *
+	 * CSIXA_LNR0 --> D2
+	 * CSIXA_LNR1 --> D0
+	 * CSIXA_LNR2 --> C
+	 * CSIXB_LNR0 --> D1
+	 * CSIXB_LNR1 --> D3
+	 */
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L0_CKMODE_EN, 0);
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L0_CKSEL, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L1_CKMODE_EN, 0);
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L1_CKSEL, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L2_CKMODE_EN, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L2_CKSEL, 1);
+
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA,
+			     RG_CSIXA_DPHY_L0_CKMODE_EN, 0);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L0_CKSEL, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA,
+			     RG_CSIXA_DPHY_L1_CKMODE_EN, 0);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L1_CKSEL, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA,
+			     RG_CSIXA_DPHY_L2_CKMODE_EN, 0);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA, RG_CSIXA_DPHY_L2_CKSEL, 1);
+
+	/* Byte clock invert */
+	mtk_phy_update_field(base + MIPI_RX_ANAA8_CSIXA, RG_CSIXA_CDPHY_L0_T0_BYTECK_INVERT, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANAA8_CSIXA, RG_CSIXA_DPHY_L1_BYTECK_INVERT, 1);
+	mtk_phy_update_field(base + MIPI_RX_ANAA8_CSIXA, RG_CSIXA_CDPHY_L2_T1_BYTECK_INVERT, 1);
+
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANAA8_CSIXA,
+			     RG_CSIXA_CDPHY_L0_T0_BYTECK_INVERT, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANAA8_CSIXA,
+			     RG_CSIXA_DPHY_L1_BYTECK_INVERT, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANAA8_CSIXA,
+			     RG_CSIXA_CDPHY_L2_T1_BYTECK_INVERT, 1);
+
+	/* Start ANA EQ tuning */
+	if (port->type == CDPHY)
+		mtk_phy_csi_cdphy_ana_eq_tune(base);
+	else
+		mtk_phy_csi_dphy_ana_eq_tune(base);
+
+	/* End ANA EQ tuning */
+	mtk_phy_set_bits(base + MIPI_RX_ANA40_CSIXA, 0x90);
+
+	mtk_phy_update_field(base + MIPI_RX_ANA24_CSIXA, RG_CSIXA_RESERVE, 0x40);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA24_CSIXA, RG_CSIXA_RESERVE, 0x40);
+	mtk_phy_update_field(base + MIPI_RX_WRAPPER80_CSIXA, CSR_CSI_RST_MODE, 0);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_WRAPPER80_CSIXA, CSR_CSI_RST_MODE, 0);
+	/* ANA power on */
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_BG_CORE_EN, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA, RG_CSIXA_BG_CORE_EN, 1);
+	usleep_range(20, 40);
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_BG_LPF_EN, 1);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA, RG_CSIXA_BG_LPF_EN, 1);
+
+	return 0;
+}
+
+static int mtk_mipi_phy_power_off(struct phy *phy)
+{
+	struct mtk_mipi_cdphy_port *port = phy_get_drvdata(phy);
+	void __iomem *base = port->base;
+
+	/* Disable MIPI BG. */
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_BG_CORE_EN, 0);
+	mtk_phy_update_field(base + MIPI_RX_ANA00_CSIXA, RG_CSIXA_BG_LPF_EN, 0);
+
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA, RG_CSIXA_BG_CORE_EN, 0);
+	mtk_phy_update_field(base + CSIXB_OFFSET + MIPI_RX_ANA00_CSIXA, RG_CSIXA_BG_LPF_EN, 0);
+
+	return 0;
+}
+
+static struct phy *mtk_mipi_cdphy_xlate(struct device *dev,
+					struct of_phandle_args *args)
+{
+	struct mtk_mipi_cdphy_port *priv = dev_get_drvdata(dev);
+
+	/*
+	 * If PHY is CD-PHY then we need to get the operating mode
+	 * For now only D-PHY mode is supported
+	 */
+	if (priv->type == CDPHY) {
+		if (args->args_count != 1) {
+			dev_err(dev, "invalid number of arguments\n");
+			return ERR_PTR(-EINVAL);
+		}
+		switch (args->args[0]) {
+		case PHY_TYPE_DPHY:
+			priv->mode = DPHY;
+			if (priv->num_lanes != 4) {
+				dev_err(dev, "Only 4D1C mode is supported for now!\n");
+				return ERR_PTR(-EINVAL);
+			}
+			break;
+		default:
+			dev_err(dev, "Unsupported PHY type: %i\n", args->args[0]);
+			return ERR_PTR(-EINVAL);
+		}
+	} else {
+		if (args->args_count) {
+			dev_err(dev, "invalid number of arguments\n");
+			return ERR_PTR(-EINVAL);
+		}
+		priv->mode = DPHY;
+	}
+
+	return priv->phy;
+}
+
+static const struct phy_ops mtk_cdphy_ops = {
+	.power_on	= mtk_mipi_phy_power_on,
+	.power_off	= mtk_mipi_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int mtk_mipi_cdphy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct phy_provider *phy_provider;
+	struct mtk_mipi_cdphy_port *port;
+	struct phy *phy;
+	int ret;
+	u32 phy_type;
+
+	port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, port);
+
+	port->dev = dev;
+
+	port->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(port->base))
+		return PTR_ERR(port->base);
+
+	ret = of_property_read_u32(dev->of_node, "num-lanes", &port->num_lanes);
+	if (ret) {
+		dev_err(dev, "Failed to read num-lanes property: %i\n", ret);
+		return ret;
+	}
+
+	/*
+	 * phy-type is optional, if not present, PHY is considered to be CD-PHY
+	 */
+	if (device_property_present(dev, "phy-type")) {
+		ret = of_property_read_u32(dev->of_node, "phy-type", &phy_type);
+		if (ret) {
+			dev_err(dev, "Failed to read phy-type property: %i\n", ret);
+			return ret;
+		}
+		switch (phy_type) {
+		case PHY_TYPE_DPHY:
+			port->type = DPHY;
+			break;
+		default:
+			dev_err(dev, "Unsupported PHY type: %i\n", phy_type);
+			return -EINVAL;
+		}
+	} else {
+		port->type = CDPHY;
+	}
+
+	phy = devm_phy_create(dev, NULL, &mtk_cdphy_ops);
+	if (IS_ERR(phy)) {
+		dev_err(dev, "Failed to create PHY: %ld\n", PTR_ERR(phy));
+		return PTR_ERR(phy);
+	}
+
+	port->phy = phy;
+	phy_set_drvdata(phy, port);
+
+	phy_provider = devm_of_phy_provider_register(dev, mtk_mipi_cdphy_xlate);
+	if (IS_ERR(phy_provider)) {
+		dev_err(dev, "Failed to register PHY provider: %ld\n",
+			PTR_ERR(phy_provider));
+		return PTR_ERR(phy_provider);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id mtk_mipi_cdphy_of_match[] = {
+	{ .compatible = "mediatek,mt8365-csi-rx" },
+	{ /* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, mtk_mipi_cdphy_of_match);
+
+static struct platform_driver mipi_cdphy_pdrv = {
+	.probe = mtk_mipi_cdphy_probe,
+	.driver	= {
+		.name	= "mtk-mipi-csi-0-5",
+		.of_match_table = mtk_mipi_cdphy_of_match,
+	},
+};
+module_platform_driver(mipi_cdphy_pdrv);
+
+MODULE_DESCRIPTION("MediaTek MIPI CSI CD-PHY v0.5 Driver");
+MODULE_AUTHOR("Louis Kuo <louis.kuo@mediatek.com>");
+MODULE_LICENSE("GPL");