imx8qm-ldb.c

// SPDX-License-Identifier: GPL-2.0+

/*
 * Copyright 2020 NXP
 */

#include <linux/clk.h>
#include <linux/media-bus-format.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>

#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_connector.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>

#include "imx-ldb-helper.h"

#define  LDB_CH0_10BIT_EN		BIT(22)
#define  LDB_CH1_10BIT_EN		BIT(23)
#define  LDB_CH0_DATA_WIDTH_24BIT	BIT(24)
#define  LDB_CH1_DATA_WIDTH_24BIT	BIT(26)
#define  LDB_CH0_DATA_WIDTH_30BIT	(2 << 24)
#define  LDB_CH1_DATA_WIDTH_30BIT	(2 << 26)

#define SS_CTRL				0x20
#define  CH_HSYNC_M(id)			BIT(0 + ((id) * 2))
#define  CH_VSYNC_M(id)			BIT(1 + ((id) * 2))
#define  CH_PHSYNC(id)			BIT(0 + ((id) * 2))
#define  CH_PVSYNC(id)			BIT(1 + ((id) * 2))

#define DRIVER_NAME			"imx8qm-ldb"

struct imx8qm_ldb_channel {
	struct ldb_channel base;
	struct phy *phy;
};

struct imx8qm_ldb {
	struct ldb base;
	struct device *dev;
	struct imx8qm_ldb_channel *channel[MAX_LDB_CHAN_NUM];
	struct clk *clk_pixel;
	struct clk *clk_bypass;
	int active_chno;
};

static inline struct imx8qm_ldb_channel *
base_to_imx8qm_ldb_channel(struct ldb_channel *base)
{
	return container_of(base, struct imx8qm_ldb_channel, base);
}

static inline struct imx8qm_ldb *base_to_imx8qm_ldb(struct ldb *base)
{
	return container_of(base, struct imx8qm_ldb, base);
}

static void imx8qm_ldb_set_phy_cfg(struct imx8qm_ldb *imx8qm_ldb,
				   unsigned long di_clk,
				   bool is_split, bool is_slave,
				   struct phy_configure_opts_lvds *phy_cfg)
{
	phy_cfg->bits_per_lane_and_dclk_cycle = 7;
	phy_cfg->lanes = 4;
	phy_cfg->differential_clk_rate = is_split ? di_clk / 2 : di_clk;
	phy_cfg->is_slave = is_slave;
}

static int imx8qm_ldb_bridge_atomic_check(struct drm_bridge *bridge,
					  struct drm_bridge_state *bridge_state,
					  struct drm_crtc_state *crtc_state,
					  struct drm_connector_state *conn_state)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qm_ldb_channel *imx8qm_ldb_ch =
					base_to_imx8qm_ldb_channel(ldb_ch);
	struct imx8qm_ldb *imx8qm_ldb = base_to_imx8qm_ldb(ldb);
	struct drm_display_mode *adj = &crtc_state->adjusted_mode;
	unsigned long di_clk = adj->clock * 1000;
	bool is_split = ldb_channel_is_split_link(ldb_ch);
	union phy_configure_opts opts = { };
	struct phy_configure_opts_lvds *phy_cfg = &opts.lvds;
	int ret;

	ret = ldb_bridge_atomic_check_helper(bridge, bridge_state,
					     crtc_state, conn_state);
	if (ret)
		return ret;

	imx8qm_ldb_set_phy_cfg(imx8qm_ldb, di_clk, is_split, false, phy_cfg);
	ret = phy_validate(imx8qm_ldb_ch->phy, PHY_MODE_LVDS, 0, &opts);
	if (ret < 0) {
		DRM_DEV_DEBUG_DRIVER(imx8qm_ldb->dev,
				     "failed to validate PHY: %d\n", ret);
		return ret;
	}

	if (is_split) {
		imx8qm_ldb_ch =
			imx8qm_ldb->channel[imx8qm_ldb->active_chno ^ 1];
		imx8qm_ldb_set_phy_cfg(imx8qm_ldb, di_clk, is_split, true,
				       phy_cfg);
		ret = phy_validate(imx8qm_ldb_ch->phy, PHY_MODE_LVDS, 0, &opts);
		if (ret < 0) {
			DRM_DEV_DEBUG_DRIVER(imx8qm_ldb->dev,
					     "failed to validate slave PHY: %d\n",
					     ret);
			return ret;
		}
	}

	return ret;
}

static void
imx8qm_ldb_bridge_mode_set(struct drm_bridge *bridge,
			   const struct drm_display_mode *mode,
			   const struct drm_display_mode *adjusted_mode)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qm_ldb_channel *imx8qm_ldb_ch =
					base_to_imx8qm_ldb_channel(ldb_ch);
	struct imx8qm_ldb *imx8qm_ldb = base_to_imx8qm_ldb(ldb);
	struct device *dev = imx8qm_ldb->dev;
	unsigned long di_clk = adjusted_mode->clock * 1000;
	bool is_split = ldb_channel_is_split_link(ldb_ch);
	union phy_configure_opts opts = { };
	struct phy_configure_opts_lvds *phy_cfg = &opts.lvds;
	u32 chno = ldb_ch->chno;
	int ret;

	ret = pm_runtime_get_sync(dev);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to get runtime PM sync: %d\n", ret);

	ret = phy_init(imx8qm_ldb_ch->phy);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to initialize PHY: %d\n", ret);

	clk_set_rate(imx8qm_ldb->clk_bypass, di_clk);
	clk_set_rate(imx8qm_ldb->clk_pixel, di_clk);

	imx8qm_ldb_set_phy_cfg(imx8qm_ldb, di_clk, is_split, false, phy_cfg);
	ret = phy_configure(imx8qm_ldb_ch->phy, &opts);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to configure PHY: %d\n", ret);

	if (is_split) {
		imx8qm_ldb_ch =
			imx8qm_ldb->channel[imx8qm_ldb->active_chno ^ 1];
		imx8qm_ldb_set_phy_cfg(imx8qm_ldb, di_clk, is_split, true,
				       phy_cfg);
		ret = phy_configure(imx8qm_ldb_ch->phy, &opts);
		if (ret < 0)
			DRM_DEV_ERROR(dev, "failed to configure slave PHY: %d\n",
				      ret);
	}

	/* input VSYNC signal from pixel link is active low */
	if (ldb_ch->chno == 0 || is_split)
		ldb->ldb_ctrl |= LDB_DI0_VS_POL_ACT_LOW;
	if (ldb_ch->chno == 1 || is_split)
		ldb->ldb_ctrl |= LDB_DI1_VS_POL_ACT_LOW;

	switch (ldb_ch->out_bus_format) {
	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
		break;
	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
		if (ldb_ch->chno == 0 || is_split)
			ldb->ldb_ctrl |= LDB_CH0_DATA_WIDTH_24BIT;
		if (ldb_ch->chno == 1 || is_split)
			ldb->ldb_ctrl |= LDB_CH1_DATA_WIDTH_24BIT;
		break;
	}

	ldb_bridge_mode_set_helper(bridge, mode, adjusted_mode);

	if (adjusted_mode->flags & DRM_MODE_FLAG_NVSYNC)
		regmap_update_bits(ldb->regmap, SS_CTRL, CH_VSYNC_M(chno), 0);
	else if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC)
		regmap_update_bits(ldb->regmap, SS_CTRL,
				   CH_VSYNC_M(chno), CH_PVSYNC(chno));

	if (adjusted_mode->flags & DRM_MODE_FLAG_NHSYNC)
		regmap_update_bits(ldb->regmap, SS_CTRL, CH_HSYNC_M(chno), 0);
	else if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC)
		regmap_update_bits(ldb->regmap, SS_CTRL,
				   CH_HSYNC_M(chno), CH_PHSYNC(chno));
}

static void imx8qm_ldb_bridge_atomic_enable(struct drm_bridge *bridge,
					    struct drm_atomic_state *state)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qm_ldb_channel *imx8qm_ldb_ch =
					base_to_imx8qm_ldb_channel(ldb_ch);
	struct imx8qm_ldb *imx8qm_ldb = base_to_imx8qm_ldb(ldb);
	struct device *dev = imx8qm_ldb->dev;
	bool is_split = ldb_channel_is_split_link(ldb_ch);
	int ret;

	clk_prepare_enable(imx8qm_ldb->clk_pixel);
	clk_prepare_enable(imx8qm_ldb->clk_bypass);

	/* both DI0 and DI1 connect with pixel link, so ok to use DI0 only */
	if (ldb_ch->chno == 0 || is_split) {
		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
		ldb->ldb_ctrl |= LDB_CH0_MODE_EN_TO_DI0;
	}
	if (ldb_ch->chno == 1 || is_split) {
		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
		ldb->ldb_ctrl |= LDB_CH1_MODE_EN_TO_DI0;
	}

	if (is_split) {
		ret = phy_power_on(imx8qm_ldb->channel[0]->phy);
		if (ret)
			DRM_DEV_ERROR(dev,
				      "failed to power on channel0 PHY: %d\n",
				      ret);

		ret = phy_power_on(imx8qm_ldb->channel[1]->phy);
		if (ret)
			DRM_DEV_ERROR(dev,
				      "failed to power on channel1 PHY: %d\n",
				      ret);
	} else {
		ret = phy_power_on(imx8qm_ldb_ch->phy);
		if (ret)
			DRM_DEV_ERROR(dev, "failed to power on PHY: %d\n", ret);
	}

	ldb_bridge_enable_helper(bridge);
}

static void imx8qm_ldb_bridge_atomic_disable(struct drm_bridge *bridge,
					     struct drm_atomic_state *state)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	struct ldb *ldb = ldb_ch->ldb;
	struct imx8qm_ldb_channel *imx8qm_ldb_ch =
					base_to_imx8qm_ldb_channel(ldb_ch);
	struct imx8qm_ldb *imx8qm_ldb = base_to_imx8qm_ldb(ldb);
	struct device *dev = imx8qm_ldb->dev;
	bool is_split = ldb_channel_is_split_link(ldb_ch);
	int ret;

	ldb_bridge_disable_helper(bridge);

	if (is_split) {
		ret = phy_power_off(imx8qm_ldb->channel[0]->phy);
		if (ret)
			DRM_DEV_ERROR(dev,
				      "failed to power off channel0 PHY: %d\n",
				      ret);
		ret = phy_power_off(imx8qm_ldb->channel[1]->phy);
		if (ret)
			DRM_DEV_ERROR(dev,
				      "failed to power off channel1 PHY: %d\n",
				      ret);
	} else {
		ret = phy_power_off(imx8qm_ldb_ch->phy);
		if (ret)
			DRM_DEV_ERROR(dev, "failed to power off PHY: %d\n", ret);
	}

	clk_disable_unprepare(imx8qm_ldb->clk_bypass);
	clk_disable_unprepare(imx8qm_ldb->clk_pixel);

	ret = pm_runtime_put(dev);
	if (ret < 0)
		DRM_DEV_ERROR(dev, "failed to put runtime PM: %d\n", ret);
}

static const u32 imx8qm_ldb_bus_output_fmts[] = {
	MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,
	MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
	MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,
	MEDIA_BUS_FMT_FIXED,
};

static bool imx8qm_ldb_bus_output_fmt_supported(u32 fmt)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(imx8qm_ldb_bus_output_fmts); i++) {
		if (imx8qm_ldb_bus_output_fmts[i] == fmt)
			return true;
	}

	return false;
}

static u32 *
imx8qm_ldb_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
					    struct drm_bridge_state *bridge_state,
					    struct drm_crtc_state *crtc_state,
					    struct drm_connector_state *conn_state,
					    u32 output_fmt,
					    unsigned int *num_input_fmts)
{
	struct drm_display_info *di;
	const struct drm_format_info *finfo;
	u32 *input_fmts;

	if (!imx8qm_ldb_bus_output_fmt_supported(output_fmt))
		return NULL;

	*num_input_fmts = 1;

	input_fmts = kmalloc(sizeof(*input_fmts), GFP_KERNEL);
	if (!input_fmts)
		return NULL;

	switch (output_fmt) {
	case MEDIA_BUS_FMT_FIXED:
		di = &conn_state->connector->display_info;

		/*
		 * Look at the first bus format to determine input format.
		 * Default to MEDIA_BUS_FMT_RGB888_1X36_CPADLO, if no match.
		 */
		if (di->num_bus_formats) {
			finfo = drm_format_info(di->bus_formats[0]);

			input_fmts[0] = finfo->depth == 18 ?
					MEDIA_BUS_FMT_RGB666_1X36_CPADLO :
					MEDIA_BUS_FMT_RGB888_1X36_CPADLO;
		} else {
			input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X36_CPADLO;
		}
		break;
	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
		input_fmts[0] = MEDIA_BUS_FMT_RGB666_1X36_CPADLO;
		break;
	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X36_CPADLO;
		break;
	default:
		kfree(input_fmts);
		input_fmts = NULL;
		break;
	}

	return input_fmts;
}

static u32 *
imx8qm_ldb_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
					     struct drm_bridge_state *bridge_state,
					     struct drm_crtc_state *crtc_state,
					     struct drm_connector_state *conn_state,
					     unsigned int *num_output_fmts)
{
	*num_output_fmts = ARRAY_SIZE(imx8qm_ldb_bus_output_fmts);
	return kmemdup(imx8qm_ldb_bus_output_fmts,
			sizeof(imx8qm_ldb_bus_output_fmts), GFP_KERNEL);
}

static enum drm_mode_status
imx8qm_ldb_bridge_mode_valid(struct drm_bridge *bridge,
			     const struct drm_display_info *info,
			     const struct drm_display_mode *mode)
{
	struct ldb_channel *ldb_ch = bridge->driver_private;
	bool is_single = ldb_channel_is_single_link(ldb_ch);

	if (mode->clock > 300000)
		return MODE_CLOCK_HIGH;

	if (mode->clock > 150000 && is_single)
		return MODE_CLOCK_HIGH;

	return MODE_OK;
}

static const struct drm_bridge_funcs imx8qm_ldb_bridge_funcs = {
	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
	.atomic_reset		= drm_atomic_helper_bridge_reset,
	.mode_valid		= imx8qm_ldb_bridge_mode_valid,
	.attach			= ldb_bridge_attach_helper,
	.atomic_check		= imx8qm_ldb_bridge_atomic_check,
	.mode_set		= imx8qm_ldb_bridge_mode_set,
	.atomic_enable		= imx8qm_ldb_bridge_atomic_enable,
	.atomic_disable		= imx8qm_ldb_bridge_atomic_disable,
	.atomic_get_input_bus_fmts =
			imx8qm_ldb_bridge_atomic_get_input_bus_fmts,
	.atomic_get_output_bus_fmts =
			imx8qm_ldb_bridge_atomic_get_output_bus_fmts,
};

static int imx8qm_ldb_get_phy(struct imx8qm_ldb *imx8qm_ldb)
{
	struct imx8qm_ldb_channel *imx8qm_ldb_ch;
	struct ldb_channel *ldb_ch;
	struct device *dev = imx8qm_ldb->dev;
	int i, ret;

	for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
		imx8qm_ldb_ch = imx8qm_ldb->channel[i];
		ldb_ch = &imx8qm_ldb_ch->base;

		if (!ldb_ch->is_available)
			continue;

		imx8qm_ldb_ch->phy = devm_of_phy_get(dev, ldb_ch->np,
						     "lvds_phy");
		if (IS_ERR(imx8qm_ldb_ch->phy)) {
			ret = PTR_ERR(imx8qm_ldb_ch->phy);
			if (ret != -EPROBE_DEFER)
				DRM_DEV_ERROR(dev,
					      "failed to get channel%d PHY: %d\n",
					      i, ret);
			return ret;
		}
	}

	return 0;
}

static int imx8qm_ldb_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct imx8qm_ldb *imx8qm_ldb;
	struct imx8qm_ldb_channel *imx8qm_ldb_ch;
	struct ldb *ldb;
	struct ldb_channel *ldb_ch;
	struct device_node *port1, *port2;
	int pixel_order;
	int ret, i;

	imx8qm_ldb = devm_kzalloc(dev, sizeof(*imx8qm_ldb), GFP_KERNEL);
	if (!imx8qm_ldb)
		return -ENOMEM;

	for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
		imx8qm_ldb->channel[i] =
			devm_drm_bridge_alloc(dev, struct imx8qm_ldb_channel, base.bridge,
					      &imx8qm_ldb_bridge_funcs);
		if (IS_ERR(imx8qm_ldb->channel[i]))
			return PTR_ERR(imx8qm_ldb->channel[i]);
	}

	imx8qm_ldb->clk_pixel = devm_clk_get(dev, "pixel");
	if (IS_ERR(imx8qm_ldb->clk_pixel)) {
		ret = PTR_ERR(imx8qm_ldb->clk_pixel);
		if (ret != -EPROBE_DEFER)
			DRM_DEV_ERROR(dev,
				      "failed to get pixel clock: %d\n", ret);
		return ret;
	}

	imx8qm_ldb->clk_bypass = devm_clk_get(dev, "bypass");
	if (IS_ERR(imx8qm_ldb->clk_bypass)) {
		ret = PTR_ERR(imx8qm_ldb->clk_bypass);
		if (ret != -EPROBE_DEFER)
			DRM_DEV_ERROR(dev,
				      "failed to get bypass clock: %d\n", ret);
		return ret;
	}

	imx8qm_ldb->dev = dev;

	ldb = &imx8qm_ldb->base;
	ldb->dev = dev;
	ldb->ctrl_reg = 0xe0;

	for (i = 0; i < MAX_LDB_CHAN_NUM; i++)
		ldb->channel[i] = &imx8qm_ldb->channel[i]->base;

	ret = ldb_init_helper(ldb);
	if (ret)
		return ret;

	if (ldb->available_ch_cnt == 0) {
		DRM_DEV_DEBUG_DRIVER(dev, "no available channel\n");
		return 0;
	}

	if (ldb->available_ch_cnt == 2) {
		port1 = of_graph_get_port_by_id(ldb->channel[0]->np, 1);
		port2 = of_graph_get_port_by_id(ldb->channel[1]->np, 1);
		pixel_order =
			drm_of_lvds_get_dual_link_pixel_order(port1, port2);
		of_node_put(port1);
		of_node_put(port2);

		if (pixel_order != DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS) {
			DRM_DEV_ERROR(dev, "invalid dual link pixel order: %d\n",
				      pixel_order);
			return -EINVAL;
		}

		imx8qm_ldb->active_chno = 0;
		imx8qm_ldb_ch = imx8qm_ldb->channel[0];
		ldb_ch = &imx8qm_ldb_ch->base;
		ldb_ch->link_type = pixel_order;
	} else {
		for (i = 0; i < MAX_LDB_CHAN_NUM; i++) {
			imx8qm_ldb_ch = imx8qm_ldb->channel[i];
			ldb_ch = &imx8qm_ldb_ch->base;

			if (ldb_ch->is_available) {
				imx8qm_ldb->active_chno = ldb_ch->chno;
				break;
			}
		}
	}

	ret = imx8qm_ldb_get_phy(imx8qm_ldb);
	if (ret)
		return ret;

	ret = ldb_find_next_bridge_helper(ldb);
	if (ret)
		return ret;

	platform_set_drvdata(pdev, imx8qm_ldb);
	pm_runtime_enable(dev);

	ldb_add_bridge_helper(ldb);

	return ret;
}

static void imx8qm_ldb_remove(struct platform_device *pdev)
{
	struct imx8qm_ldb *imx8qm_ldb = platform_get_drvdata(pdev);
	struct ldb *ldb = &imx8qm_ldb->base;

	ldb_remove_bridge_helper(ldb);

	pm_runtime_disable(&pdev->dev);
}

static int imx8qm_ldb_runtime_suspend(struct device *dev)
{
	return 0;
}

static int imx8qm_ldb_runtime_resume(struct device *dev)
{
	struct imx8qm_ldb *imx8qm_ldb = dev_get_drvdata(dev);
	struct ldb *ldb = &imx8qm_ldb->base;

	/* disable LDB by resetting the control register to POR default */
	regmap_write(ldb->regmap, ldb->ctrl_reg, 0);

	return 0;
}

static const struct dev_pm_ops imx8qm_ldb_pm_ops = {
	RUNTIME_PM_OPS(imx8qm_ldb_runtime_suspend, imx8qm_ldb_runtime_resume, NULL)
};

static const struct of_device_id imx8qm_ldb_dt_ids[] = {
	{ .compatible = "fsl,imx8qm-ldb" },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, imx8qm_ldb_dt_ids);

static struct platform_driver imx8qm_ldb_driver = {
	.probe	= imx8qm_ldb_probe,
	.remove = imx8qm_ldb_remove,
	.driver	= {
		.pm = pm_ptr(&imx8qm_ldb_pm_ops),
		.name = DRIVER_NAME,
		.of_match_table = imx8qm_ldb_dt_ids,
	},
};
module_platform_driver(imx8qm_ldb_driver);

MODULE_DESCRIPTION("i.MX8QM LVDS Display Bridge(LDB)/Pixel Mapper bridge driver");
MODULE_AUTHOR("Liu Ying <[email protected]>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);