drm/meson: add support for MIPI-DSI transceiver

The Amlogic G12A/G12B/SM1 SoCs embeds a Synopsys DW-MIPI-DSI transceiver
(ver 1.21a), with a custom glue managing the IP resets, clock and data
inputs similar to the DW-HDMI Glue on other Amlogic SoCs.

This adds support for the Glue managing the transceiver, mimicing the init
flow provided by Amlogic to setup the ENCL encoder, the glue, the transceiver,
the digital D-PHY and the Analog PHY in the proper way.

An optional "MEAS" clock can be enabled to measure the delay between each
vsync feeding the DW-MIPI-DSI transceiver.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Nicolas Belin <nbelin@baylibre.com>
Tested-by: Nicolas Belin <nbelin@baylibre.com> # on Khadas VIM3 + TS050 Panel
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230512-amlogic-v6-4-upstream-dsi-ccf-vim3-v5-12-56eb7a4d5b8e@linaro.org

Author: superna9999

drivers/gpu/drm/meson/Kconfig

@@ -17,3 +17,10 @@ config DRM_MESON_DW_HDMI
 	default y if DRM_MESON
 	select DRM_DW_HDMI
 	imply DRM_DW_HDMI_I2S_AUDIO
+
+config DRM_MESON_DW_MIPI_DSI
+	tristate "MIPI DSI Synopsys Controller support for Amlogic Meson Display"
+	depends on DRM_MESON
+	default y if DRM_MESON
+	select DRM_DW_MIPI_DSI
+	select GENERIC_PHY_MIPI_DPHY

drivers/gpu/drm/meson/Makefile

@@ -6,3 +6,4 @@ meson-drm-y += meson_encoder_hdmi.o meson_encoder_dsi.o
 
 obj-$(CONFIG_DRM_MESON) += meson-drm.o
 obj-$(CONFIG_DRM_MESON_DW_HDMI) += meson_dw_hdmi.o
+obj-$(CONFIG_DRM_MESON_DW_MIPI_DSI) += meson_dw_mipi_dsi.o

drivers/gpu/drm/meson/meson_dw_mipi_dsi.c

@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2021 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
+ */
+
+#include <linux/clk.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/reset.h>
+#include <linux/phy/phy.h>
+#include <linux/bitfield.h>
+
+#include <video/mipi_display.h>
+
+#include <drm/bridge/dw_mipi_dsi.h>
+#include <drm/drm_mipi_dsi.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_device.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_print.h>
+
+#include "meson_drv.h"
+#include "meson_dw_mipi_dsi.h"
+#include "meson_registers.h"
+#include "meson_venc.h"
+
+#define DRIVER_NAME "meson-dw-mipi-dsi"
+#define DRIVER_DESC "Amlogic Meson MIPI-DSI DRM driver"
+
+struct meson_dw_mipi_dsi {
+	struct meson_drm *priv;
+	struct device *dev;
+	void __iomem *base;
+	struct phy *phy;
+	union phy_configure_opts phy_opts;
+	struct dw_mipi_dsi *dmd;
+	struct dw_mipi_dsi_plat_data pdata;
+	struct mipi_dsi_device *dsi_device;
+	const struct drm_display_mode *mode;
+	struct clk *bit_clk;
+	struct clk *px_clk;
+	struct reset_control *top_rst;
+};
+
+#define encoder_to_meson_dw_mipi_dsi(x) \
+	container_of(x, struct meson_dw_mipi_dsi, encoder)
+
+static void meson_dw_mipi_dsi_hw_init(struct meson_dw_mipi_dsi *mipi_dsi)
+{
+	/* Software reset */
+	writel_bits_relaxed(MIPI_DSI_TOP_SW_RESET_DWC | MIPI_DSI_TOP_SW_RESET_INTR |
+			    MIPI_DSI_TOP_SW_RESET_DPI | MIPI_DSI_TOP_SW_RESET_TIMING,
+			    MIPI_DSI_TOP_SW_RESET_DWC | MIPI_DSI_TOP_SW_RESET_INTR |
+			    MIPI_DSI_TOP_SW_RESET_DPI | MIPI_DSI_TOP_SW_RESET_TIMING,
+			    mipi_dsi->base + MIPI_DSI_TOP_SW_RESET);
+	writel_bits_relaxed(MIPI_DSI_TOP_SW_RESET_DWC | MIPI_DSI_TOP_SW_RESET_INTR |
+			    MIPI_DSI_TOP_SW_RESET_DPI | MIPI_DSI_TOP_SW_RESET_TIMING,
+			    0, mipi_dsi->base + MIPI_DSI_TOP_SW_RESET);
+
+	/* Enable clocks */
+	writel_bits_relaxed(MIPI_DSI_TOP_CLK_SYSCLK_EN | MIPI_DSI_TOP_CLK_PIXCLK_EN,
+			    MIPI_DSI_TOP_CLK_SYSCLK_EN | MIPI_DSI_TOP_CLK_PIXCLK_EN,
+			    mipi_dsi->base + MIPI_DSI_TOP_CLK_CNTL);
+
+	/* Take memory out of power down */
+	writel_relaxed(0, mipi_dsi->base + MIPI_DSI_TOP_MEM_PD);
+}
+
+static int dw_mipi_dsi_phy_init(void *priv_data)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi = priv_data;
+	unsigned int dpi_data_format, venc_data_width;
+	int ret;
+
+	/* Set the bit clock rate to hs_clk_rate */
+	ret = clk_set_rate(mipi_dsi->bit_clk,
+			   mipi_dsi->phy_opts.mipi_dphy.hs_clk_rate);
+	if (ret) {
+		dev_err(mipi_dsi->dev, "Failed to set DSI Bit clock rate %lu (ret %d)\n",
+			mipi_dsi->phy_opts.mipi_dphy.hs_clk_rate, ret);
+		return ret;
+	}
+
+	/* Make sure the rate of the bit clock is not modified by someone else */
+	ret = clk_rate_exclusive_get(mipi_dsi->bit_clk);
+	if (ret) {
+		dev_err(mipi_dsi->dev,
+			"Failed to set the exclusivity on the bit clock rate (ret %d)\n", ret);
+		return ret;
+	}
+
+	ret = clk_set_rate(mipi_dsi->px_clk, mipi_dsi->mode->clock * 1000);
+
+	if (ret) {
+		dev_err(mipi_dsi->dev, "Failed to set DSI Pixel clock rate %u (%d)\n",
+			mipi_dsi->mode->clock * 1000, ret);
+		return ret;
+	}
+
+	switch (mipi_dsi->dsi_device->format) {
+	case MIPI_DSI_FMT_RGB888:
+		dpi_data_format = DPI_COLOR_24BIT;
+		venc_data_width = VENC_IN_COLOR_24B;
+		break;
+	case MIPI_DSI_FMT_RGB666:
+		dpi_data_format = DPI_COLOR_18BIT_CFG_2;
+		venc_data_width = VENC_IN_COLOR_18B;
+		break;
+	case MIPI_DSI_FMT_RGB666_PACKED:
+	case MIPI_DSI_FMT_RGB565:
+		return -EINVAL;
+	};
+
+	/* Configure color format for DPI register */
+	writel_relaxed(FIELD_PREP(MIPI_DSI_TOP_DPI_COLOR_MODE, dpi_data_format) |
+		       FIELD_PREP(MIPI_DSI_TOP_IN_COLOR_MODE, venc_data_width) |
+		       FIELD_PREP(MIPI_DSI_TOP_COMP2_SEL, 2) |
+		       FIELD_PREP(MIPI_DSI_TOP_COMP1_SEL, 1) |
+		       FIELD_PREP(MIPI_DSI_TOP_COMP0_SEL, 0),
+			mipi_dsi->base + MIPI_DSI_TOP_CNTL);
+
+	return phy_configure(mipi_dsi->phy, &mipi_dsi->phy_opts);
+}
+
+static void dw_mipi_dsi_phy_power_on(void *priv_data)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi = priv_data;
+
+	if (phy_power_on(mipi_dsi->phy))
+		dev_warn(mipi_dsi->dev, "Failed to power on PHY\n");
+}
+
+static void dw_mipi_dsi_phy_power_off(void *priv_data)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi = priv_data;
+
+	if (phy_power_off(mipi_dsi->phy))
+		dev_warn(mipi_dsi->dev, "Failed to power off PHY\n");
+
+	/* Remove the exclusivity on the bit clock rate */
+	clk_rate_exclusive_put(mipi_dsi->bit_clk);
+}
+
+static int
+dw_mipi_dsi_get_lane_mbps(void *priv_data, const struct drm_display_mode *mode,
+			  unsigned long mode_flags, u32 lanes, u32 format,
+			  unsigned int *lane_mbps)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi = priv_data;
+	int bpp;
+
+	mipi_dsi->mode = mode;
+
+	bpp = mipi_dsi_pixel_format_to_bpp(mipi_dsi->dsi_device->format);
+
+	phy_mipi_dphy_get_default_config(mode->clock * 1000,
+					 bpp, mipi_dsi->dsi_device->lanes,
+					 &mipi_dsi->phy_opts.mipi_dphy);
+
+	*lane_mbps = DIV_ROUND_UP(mipi_dsi->phy_opts.mipi_dphy.hs_clk_rate, USEC_PER_SEC);
+
+	return 0;
+}
+
+static int
+dw_mipi_dsi_phy_get_timing(void *priv_data, unsigned int lane_mbps,
+			   struct dw_mipi_dsi_dphy_timing *timing)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi = priv_data;
+
+	switch (mipi_dsi->mode->hdisplay) {
+	case 240:
+	case 768:
+	case 1920:
+	case 2560:
+		timing->clk_lp2hs = 23;
+		timing->clk_hs2lp = 38;
+		timing->data_lp2hs = 15;
+		timing->data_hs2lp = 9;
+		break;
+
+	default:
+		timing->clk_lp2hs = 37;
+		timing->clk_hs2lp = 135;
+		timing->data_lp2hs = 50;
+		timing->data_hs2lp = 3;
+	}
+
+	return 0;
+}
+
+static int
+dw_mipi_dsi_get_esc_clk_rate(void *priv_data, unsigned int *esc_clk_rate)
+{
+	*esc_clk_rate = 4; /* Mhz */
+
+	return 0;
+}
+
+static const struct dw_mipi_dsi_phy_ops meson_dw_mipi_dsi_phy_ops = {
+	.init = dw_mipi_dsi_phy_init,
+	.power_on = dw_mipi_dsi_phy_power_on,
+	.power_off = dw_mipi_dsi_phy_power_off,
+	.get_lane_mbps = dw_mipi_dsi_get_lane_mbps,
+	.get_timing = dw_mipi_dsi_phy_get_timing,
+	.get_esc_clk_rate = dw_mipi_dsi_get_esc_clk_rate,
+};
+
+static int meson_dw_mipi_dsi_host_attach(void *priv_data,
+					 struct mipi_dsi_device *device)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi = priv_data;
+	int ret;
+
+	mipi_dsi->dsi_device = device;
+
+	switch (device->format) {
+	case MIPI_DSI_FMT_RGB888:
+		break;
+	case MIPI_DSI_FMT_RGB666:
+		break;
+	case MIPI_DSI_FMT_RGB666_PACKED:
+	case MIPI_DSI_FMT_RGB565:
+		dev_err(mipi_dsi->dev, "invalid pixel format %d\n", device->format);
+		return -EINVAL;
+	};
+
+	ret = phy_init(mipi_dsi->phy);
+	if (ret)
+		return ret;
+
+	meson_dw_mipi_dsi_hw_init(mipi_dsi);
+
+	return 0;
+}
+
+static int meson_dw_mipi_dsi_host_detach(void *priv_data,
+					 struct mipi_dsi_device *device)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi = priv_data;
+
+	if (device == mipi_dsi->dsi_device)
+		mipi_dsi->dsi_device = NULL;
+	else
+		return -EINVAL;
+
+	return phy_exit(mipi_dsi->phy);
+}
+
+static const struct dw_mipi_dsi_host_ops meson_dw_mipi_dsi_host_ops = {
+	.attach = meson_dw_mipi_dsi_host_attach,
+	.detach = meson_dw_mipi_dsi_host_detach,
+};
+
+static int meson_dw_mipi_dsi_probe(struct platform_device *pdev)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi;
+	struct device *dev = &pdev->dev;
+
+	mipi_dsi = devm_kzalloc(dev, sizeof(*mipi_dsi), GFP_KERNEL);
+	if (!mipi_dsi)
+		return -ENOMEM;
+
+	mipi_dsi->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mipi_dsi->base))
+		return PTR_ERR(mipi_dsi->base);
+
+	mipi_dsi->phy = devm_phy_get(dev, "dphy");
+	if (IS_ERR(mipi_dsi->phy))
+		return dev_err_probe(dev, PTR_ERR(mipi_dsi->phy),
+				     "failed to get mipi dphy\n");
+
+	mipi_dsi->bit_clk = devm_clk_get_enabled(dev, "bit");
+	if (IS_ERR(mipi_dsi->bit_clk)) {
+		int ret = PTR_ERR(mipi_dsi->bit_clk);
+
+		/* TOFIX GP0 on some platforms fails to lock in early boot, defer probe */
+		if (ret == -EIO)
+			ret = -EPROBE_DEFER;
+
+		return dev_err_probe(dev, ret, "Unable to get enabled bit_clk\n");
+	}
+
+	mipi_dsi->px_clk = devm_clk_get_enabled(dev, "px");
+	if (IS_ERR(mipi_dsi->px_clk))
+		return dev_err_probe(dev, PTR_ERR(mipi_dsi->px_clk),
+				     "Unable to get enabled px_clk\n");
+
+	/*
+	 * We use a TOP reset signal because the APB reset signal
+	 * is handled by the TOP control registers.
+	 */
+	mipi_dsi->top_rst = devm_reset_control_get_exclusive(dev, "top");
+	if (IS_ERR(mipi_dsi->top_rst))
+		return dev_err_probe(dev, PTR_ERR(mipi_dsi->top_rst),
+				     "Unable to get reset control\n");
+
+	reset_control_assert(mipi_dsi->top_rst);
+	usleep_range(10, 20);
+	reset_control_deassert(mipi_dsi->top_rst);
+
+	/* MIPI DSI Controller */
+
+	mipi_dsi->dev = dev;
+	mipi_dsi->pdata.base = mipi_dsi->base;
+	mipi_dsi->pdata.max_data_lanes = 4;
+	mipi_dsi->pdata.phy_ops = &meson_dw_mipi_dsi_phy_ops;
+	mipi_dsi->pdata.host_ops = &meson_dw_mipi_dsi_host_ops;
+	mipi_dsi->pdata.priv_data = mipi_dsi;
+	platform_set_drvdata(pdev, mipi_dsi);
+
+	mipi_dsi->dmd = dw_mipi_dsi_probe(pdev, &mipi_dsi->pdata);
+	if (IS_ERR(mipi_dsi->dmd))
+		return dev_err_probe(dev, PTR_ERR(mipi_dsi->dmd),
+				     "Failed to probe dw_mipi_dsi\n");
+
+	return 0;
+}
+
+static int meson_dw_mipi_dsi_remove(struct platform_device *pdev)
+{
+	struct meson_dw_mipi_dsi *mipi_dsi = platform_get_drvdata(pdev);
+
+	dw_mipi_dsi_remove(mipi_dsi->dmd);
+
+	return 0;
+}
+
+static const struct of_device_id meson_dw_mipi_dsi_of_table[] = {
+	{ .compatible = "amlogic,meson-g12a-dw-mipi-dsi", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, meson_dw_mipi_dsi_of_table);
+
+static struct platform_driver meson_dw_mipi_dsi_platform_driver = {
+	.probe		= meson_dw_mipi_dsi_probe,
+	.remove		= meson_dw_mipi_dsi_remove,
+	.driver		= {
+		.name		= DRIVER_NAME,
+		.of_match_table	= meson_dw_mipi_dsi_of_table,
+	},
+};
+module_platform_driver(meson_dw_mipi_dsi_platform_driver);
+
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL");