drm: lcdif: Add support for i.MX8MP LCDIF variant

Add support for i.MX8MP LCDIF variant. This is called LCDIFv3 and is
completely different from the LCDIFv3 found in i.MX23 in that it has
a completely scrambled register layout compared to all previous LCDIF
variants. The new LCDIFv3 also supports 36bit address space.

Add a separate driver which is really a fork of MXSFB driver with the
i.MX8MP LCDIF variant handling filled in.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexander Stein <alexander.stein@ew.tq-group.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Robby Cai <robby.cai@nxp.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stefan Agner <stefan@agner.ch>

drivers/gpu/drm/mxsfb/Kconfig

@@ -19,3 +19,19 @@ config DRM_MXSFB
 	  i.MX28, i.MX6SX, i.MX7 and i.MX8M).
 
 	  If M is selected the module will be called mxsfb.
+
+config DRM_IMX_LCDIF
+	tristate "i.MX LCDIFv3 LCD controller"
+	depends on DRM && OF
+	depends on COMMON_CLK
+	select DRM_MXS
+	select DRM_KMS_HELPER
+	select DRM_GEM_CMA_HELPER
+	select DRM_PANEL
+	select DRM_PANEL_BRIDGE
+	help
+	  Choose this option if you have an LCDIFv3 LCD controller.
+	  Those devices are found in various i.MX SoC (i.MX8MP,
+	  i.MXRT).
+
+	  If M is selected the module will be called imx-lcdif.

drivers/gpu/drm/mxsfb/Makefile

@@ -1,3 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 mxsfb-y := mxsfb_drv.o mxsfb_kms.o
 obj-$(CONFIG_DRM_MXSFB)	+= mxsfb.o
+imx-lcdif-y := lcdif_drv.o lcdif_kms.o
+obj-$(CONFIG_DRM_IMX_LCDIF) += imx-lcdif.o

drivers/gpu/drm/mxsfb/lcdif_drv.c

@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2022 Marek Vasut <marex@denx.de>
+ *
+ * This code is based on drivers/gpu/drm/mxsfb/mxsfb*
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_fourcc.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_mode_config.h>
+#include <drm/drm_module.h>
+#include <drm/drm_of.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_vblank.h>
+
+#include "lcdif_drv.h"
+#include "lcdif_regs.h"
+
+static struct drm_framebuffer *
+lcdif_fb_create(struct drm_device *dev, struct drm_file *file_priv,
+		const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	const struct drm_format_info *info;
+
+	info = drm_get_format_info(dev, mode_cmd);
+	if (!info)
+		return ERR_PTR(-EINVAL);
+
+	return drm_gem_fb_create(dev, file_priv, mode_cmd);
+}
+
+static const struct drm_mode_config_funcs lcdif_mode_config_funcs = {
+	.fb_create		= lcdif_fb_create,
+	.atomic_check		= drm_atomic_helper_check,
+	.atomic_commit		= drm_atomic_helper_commit,
+};
+
+static const struct drm_mode_config_helper_funcs lcdif_mode_config_helpers = {
+	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
+static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
+{
+	struct drm_device *drm = lcdif->drm;
+	struct drm_bridge *bridge;
+	struct drm_panel *panel;
+	int ret;
+
+	ret = drm_of_find_panel_or_bridge(drm->dev->of_node, 0, 0, &panel,
+					  &bridge);
+	if (ret)
+		return ret;
+
+	if (panel) {
+		bridge = devm_drm_panel_bridge_add_typed(drm->dev, panel,
+							 DRM_MODE_CONNECTOR_DPI);
+		if (IS_ERR(bridge))
+			return PTR_ERR(bridge);
+	}
+
+	if (!bridge)
+		return -ENODEV;
+
+	ret = drm_bridge_attach(&lcdif->encoder, bridge, NULL, 0);
+	if (ret)
+		return dev_err_probe(drm->dev, ret, "Failed to attach bridge\n");
+
+	lcdif->bridge = bridge;
+
+	return 0;
+}
+
+static irqreturn_t lcdif_irq_handler(int irq, void *data)
+{
+	struct drm_device *drm = data;
+	struct lcdif_drm_private *lcdif = drm->dev_private;
+	u32 reg;
+	int ret;
+
+	ret = readl_poll_timeout(lcdif->base + LCDC_V8_CTRLDESCL0_5,
+				 reg, !(reg & CTRLDESCL0_5_SHADOW_LOAD_EN),
+				 0, 36000);	/* Wait ~2 frame times max */
+	if (ret)
+		drm_err_ratelimited(drm, "Shadow load bit not cleared!\n");
+
+	reg = readl(lcdif->base + LCDC_V8_INT_STATUS_D0);
+
+	if (reg & INT_STATUS_D0_VS_BLANK)
+		drm_crtc_handle_vblank(&lcdif->crtc);
+
+	writel(INT_STATUS_D0_VS_BLANK, lcdif->base + LCDC_V8_INT_STATUS_D0);
+
+	return IRQ_HANDLED;
+}
+
+static int lcdif_load(struct drm_device *drm)
+{
+	struct platform_device *pdev = to_platform_device(drm->dev);
+	struct lcdif_drm_private *lcdif;
+	struct resource *res;
+	int ret;
+
+	lcdif = devm_kzalloc(&pdev->dev, sizeof(*lcdif), GFP_KERNEL);
+	if (!lcdif)
+		return -ENOMEM;
+
+	lcdif->drm = drm;
+	drm->dev_private = lcdif;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	lcdif->base = devm_ioremap_resource(drm->dev, res);
+	if (IS_ERR(lcdif->base))
+		return PTR_ERR(lcdif->base);
+
+	lcdif->clk = devm_clk_get(drm->dev, "pix");
+	if (IS_ERR(lcdif->clk))
+		return PTR_ERR(lcdif->clk);
+
+	lcdif->clk_axi = devm_clk_get(drm->dev, "axi");
+	if (IS_ERR(lcdif->clk_axi))
+		return PTR_ERR(lcdif->clk_axi);
+
+	lcdif->clk_disp_axi = devm_clk_get(drm->dev, "disp_axi");
+	if (IS_ERR(lcdif->clk_disp_axi))
+		return PTR_ERR(lcdif->clk_disp_axi);
+
+	platform_set_drvdata(pdev, drm);
+
+	ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(36));
+	if (ret)
+		return ret;
+
+	/* Modeset init */
+	drm_mode_config_init(drm);
+
+	ret = lcdif_kms_init(lcdif);
+	if (ret < 0) {
+		dev_err(drm->dev, "Failed to initialize KMS pipeline\n");
+		return ret;
+	}
+
+	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
+	if (ret < 0) {
+		dev_err(drm->dev, "Failed to initialise vblank\n");
+		return ret;
+	}
+
+	/* Start with vertical blanking interrupt reporting disabled. */
+	drm_crtc_vblank_off(&lcdif->crtc);
+
+	ret = lcdif_attach_bridge(lcdif);
+	if (ret)
+		return dev_err_probe(drm->dev, ret, "Cannot connect bridge\n");
+
+	drm->mode_config.min_width	= LCDIF_MIN_XRES;
+	drm->mode_config.min_height	= LCDIF_MIN_YRES;
+	drm->mode_config.max_width	= LCDIF_MAX_XRES;
+	drm->mode_config.max_height	= LCDIF_MAX_YRES;
+	drm->mode_config.funcs		= &lcdif_mode_config_funcs;
+	drm->mode_config.helper_private	= &lcdif_mode_config_helpers;
+
+	drm_mode_config_reset(drm);
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		return ret;
+	lcdif->irq = ret;
+
+	ret = request_irq(lcdif->irq, lcdif_irq_handler, 0,
+			  drm->driver->name, drm);
+	if (ret < 0) {
+		dev_err(drm->dev, "Failed to install IRQ handler\n");
+		return ret;
+	}
+
+	drm_kms_helper_poll_init(drm);
+
+	drm_helper_hpd_irq_event(drm);
+
+	pm_runtime_enable(drm->dev);
+
+	return 0;
+}
+
+static void lcdif_unload(struct drm_device *drm)
+{
+	struct lcdif_drm_private *lcdif = drm->dev_private;
+
+	pm_runtime_get_sync(drm->dev);
+
+	drm_crtc_vblank_off(&lcdif->crtc);
+
+	drm_kms_helper_poll_fini(drm);
+	drm_mode_config_cleanup(drm);
+
+	pm_runtime_put_sync(drm->dev);
+	pm_runtime_disable(drm->dev);
+
+	free_irq(lcdif->irq, drm->dev);
+
+	drm->dev_private = NULL;
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(fops);
+
+static const struct drm_driver lcdif_driver = {
+	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+	DRM_GEM_CMA_DRIVER_OPS,
+	.fops	= &fops,
+	.name	= "imx-lcdif",
+	.desc	= "i.MX LCDIF Controller DRM",
+	.date	= "20220417",
+	.major	= 1,
+	.minor	= 0,
+};
+
+static const struct of_device_id lcdif_dt_ids[] = {
+	{ .compatible = "fsl,imx8mp-lcdif" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lcdif_dt_ids);
+
+static int lcdif_probe(struct platform_device *pdev)
+{
+	struct drm_device *drm;
+	int ret;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	drm = drm_dev_alloc(&lcdif_driver, &pdev->dev);
+	if (IS_ERR(drm))
+		return PTR_ERR(drm);
+
+	ret = lcdif_load(drm);
+	if (ret)
+		goto err_free;
+
+	ret = drm_dev_register(drm, 0);
+	if (ret)
+		goto err_unload;
+
+	drm_fbdev_generic_setup(drm, 32);
+
+	return 0;
+
+err_unload:
+	lcdif_unload(drm);
+err_free:
+	drm_dev_put(drm);
+
+	return ret;
+}
+
+static int lcdif_remove(struct platform_device *pdev)
+{
+	struct drm_device *drm = platform_get_drvdata(pdev);
+
+	drm_dev_unregister(drm);
+	drm_atomic_helper_shutdown(drm);
+	lcdif_unload(drm);
+	drm_dev_put(drm);
+
+	return 0;
+}
+
+static void lcdif_shutdown(struct platform_device *pdev)
+{
+	struct drm_device *drm = platform_get_drvdata(pdev);
+
+	drm_atomic_helper_shutdown(drm);
+}
+
+static int lcdif_rpm_suspend(struct device *dev)
+{
+	struct drm_device *drm = dev_get_drvdata(dev);
+	struct lcdif_drm_private *lcdif = drm->dev_private;
+
+	/* These clock supply the DISPLAY CLOCK Domain */
+	clk_disable_unprepare(lcdif->clk);
+	/* These clock supply the System Bus, AXI, Write Path, LFIFO */
+	clk_disable_unprepare(lcdif->clk_disp_axi);
+	/* These clock supply the Control Bus, APB, APBH Ctrl Registers */
+	clk_disable_unprepare(lcdif->clk_axi);
+
+	return 0;
+}
+
+static int lcdif_rpm_resume(struct device *dev)
+{
+	struct drm_device *drm = dev_get_drvdata(dev);
+	struct lcdif_drm_private *lcdif = drm->dev_private;
+
+	/* These clock supply the Control Bus, APB, APBH Ctrl Registers */
+	clk_prepare_enable(lcdif->clk_axi);
+	/* These clock supply the System Bus, AXI, Write Path, LFIFO */
+	clk_prepare_enable(lcdif->clk_disp_axi);
+	/* These clock supply the DISPLAY CLOCK Domain */
+	clk_prepare_enable(lcdif->clk);
+
+	return 0;
+}
+
+static int lcdif_suspend(struct device *dev)
+{
+	struct drm_device *drm = dev_get_drvdata(dev);
+	int ret;
+
+	ret = drm_mode_config_helper_suspend(drm);
+	if (ret)
+		return ret;
+
+	return lcdif_rpm_suspend(dev);
+}
+
+static int lcdif_resume(struct device *dev)
+{
+	struct drm_device *drm = dev_get_drvdata(dev);
+
+	lcdif_rpm_resume(dev);
+
+	return drm_mode_config_helper_resume(drm);
+}
+
+static const struct dev_pm_ops lcdif_pm_ops = {
+	.runtime_suspend = lcdif_rpm_suspend,
+	.runtime_resume = lcdif_rpm_resume,
+	SET_SYSTEM_SLEEP_PM_OPS(lcdif_suspend, lcdif_resume)
+};
+
+static struct platform_driver lcdif_platform_driver = {
+	.probe		= lcdif_probe,
+	.remove		= lcdif_remove,
+	.shutdown	= lcdif_shutdown,
+	.driver	= {
+		.name		= "imx-lcdif",
+		.of_match_table	= lcdif_dt_ids,
+		.pm		= &lcdif_pm_ops,
+	},
+};
+
+drm_module_platform_driver(lcdif_platform_driver);
+
+MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
+MODULE_DESCRIPTION("Freescale LCDIF DRM/KMS driver");
+MODULE_LICENSE("GPL");