drm/sprd: add Unisoc's drm kms master

Adds drm support for the Unisoc's display subsystem.

This is drm kms driver, this driver provides support for the
application framework in Android, Yocto and more.

Application framework can access Unisoc's display internal
peripherals through libdrm or libkms, it's test ok by modetest
(DRM/KMS test tool) and Android HWComposer.

v4:
  - Move the devm_drm_dev_alloc to master_ops->bind function.
  - The managed drmm_mode_config_init() it is no longer necessary for drivers to explicitly call drm_mode_config_cleanup, so delete it.

v5:
  - Remove subdir-ccflgas-y for Makefile.
  - Keep the selects sorted by alphabet for Kconfig.

Cc: Orson Zhai <orsonzhai@gmail.com>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Kevin Tang <kevin.tang@unisoc.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211207142717.30296-3-kevin3.tang@gmail.com

drivers/gpu/drm/Kconfig

@@ -388,6 +388,8 @@ source "drivers/gpu/drm/xlnx/Kconfig"
 
 source "drivers/gpu/drm/gud/Kconfig"
 
+source "drivers/gpu/drm/sprd/Kconfig"
+
 config DRM_HYPERV
 	tristate "DRM Support for Hyper-V synthetic video device"
 	depends on DRM && PCI && MMU && HYPERV

drivers/gpu/drm/Makefile

@@ -134,3 +134,4 @@ obj-$(CONFIG_DRM_TIDSS) += tidss/
 obj-y			+= xlnx/
 obj-y			+= gud/
 obj-$(CONFIG_DRM_HYPERV) += hyperv/
+obj-$(CONFIG_DRM_SPRD) += sprd/

drivers/gpu/drm/sprd/Kconfig

+config DRM_SPRD
+	tristate "DRM Support for Unisoc SoCs Platform"
+	depends on ARCH_SPRD || COMPILE_TEST
+	depends on DRM && OF
+	select DRM_GEM_CMA_HELPER
+	select DRM_KMS_CMA_HELPER
+	select DRM_KMS_HELPER
+	help
+	  Choose this option if you have a Unisoc chipset.
+	  If M is selected the module will be called sprd_drm.
+

drivers/gpu/drm/sprd/Makefile

+# SPDX-License-Identifier: GPL-2.0
+
+obj-y := sprd_drm.o

drivers/gpu/drm/sprd/sprd_drm.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Unisoc Inc.
+ */
+
+#include <linux/component.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of_graph.h>
+#include <linux/of_platform.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_probe_helper.h>
+#include <drm/drm_vblank.h>
+
+#include "sprd_drm.h"
+
+#define DRIVER_NAME	"sprd"
+#define DRIVER_DESC	"Spreadtrum SoCs' DRM Driver"
+#define DRIVER_DATE	"20200201"
+#define DRIVER_MAJOR	1
+#define DRIVER_MINOR	0
+
+static const struct drm_mode_config_helper_funcs sprd_drm_mode_config_helper = {
+	.atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
+};
+
+static const struct drm_mode_config_funcs sprd_drm_mode_config_funcs = {
+	.fb_create = drm_gem_fb_create,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static void sprd_drm_mode_config_init(struct drm_device *drm)
+{
+	drm->mode_config.min_width = 0;
+	drm->mode_config.min_height = 0;
+	drm->mode_config.max_width = 8192;
+	drm->mode_config.max_height = 8192;
+	drm->mode_config.allow_fb_modifiers = true;
+
+	drm->mode_config.funcs = &sprd_drm_mode_config_funcs;
+	drm->mode_config.helper_private = &sprd_drm_mode_config_helper;
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(sprd_drm_fops);
+
+static struct drm_driver sprd_drm_drv = {
+	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+	.fops			= &sprd_drm_fops,
+
+	/* GEM Operations */
+	DRM_GEM_CMA_DRIVER_OPS,
+
+	.name			= DRIVER_NAME,
+	.desc			= DRIVER_DESC,
+	.date			= DRIVER_DATE,
+	.major			= DRIVER_MAJOR,
+	.minor			= DRIVER_MINOR,
+};
+
+static int sprd_drm_bind(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct drm_device *drm;
+	struct sprd_drm *sprd;
+	int ret;
+
+	sprd = devm_drm_dev_alloc(dev, &sprd_drm_drv, struct sprd_drm, drm);
+	if (IS_ERR(sprd))
+		return PTR_ERR(sprd);
+
+	drm = &sprd->drm;
+	platform_set_drvdata(pdev, drm);
+
+	ret = drmm_mode_config_init(drm);
+	if (ret)
+		return ret;
+
+	sprd_drm_mode_config_init(drm);
+
+	/* bind and init sub drivers */
+	ret = component_bind_all(drm->dev, drm);
+	if (ret) {
+		drm_err(drm, "failed to bind all component.\n");
+		return ret;
+	}
+
+	/* vblank init */
+	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
+	if (ret) {
+		drm_err(drm, "failed to initialize vblank.\n");
+		goto err_unbind_all;
+	}
+
+	/* reset all the states of crtc/plane/encoder/connector */
+	drm_mode_config_reset(drm);
+
+	/* init kms poll for handling hpd */
+	drm_kms_helper_poll_init(drm);
+
+	ret = drm_dev_register(drm, 0);
+	if (ret < 0)
+		goto err_kms_helper_poll_fini;
+
+	return 0;
+
+err_kms_helper_poll_fini:
+	drm_kms_helper_poll_fini(drm);
+err_unbind_all:
+	component_unbind_all(drm->dev, drm);
+	return ret;
+}
+
+static void sprd_drm_unbind(struct device *dev)
+{
+	struct drm_device *drm = dev_get_drvdata(dev);
+
+	drm_dev_unregister(drm);
+
+	drm_kms_helper_poll_fini(drm);
+
+	component_unbind_all(drm->dev, drm);
+}
+
+static const struct component_master_ops drm_component_ops = {
+	.bind = sprd_drm_bind,
+	.unbind = sprd_drm_unbind,
+};
+
+static int compare_of(struct device *dev, void *data)
+{
+	return dev->of_node == data;
+}
+
+static int sprd_drm_probe(struct platform_device *pdev)
+{
+	return drm_of_component_probe(&pdev->dev, compare_of, &drm_component_ops);
+}
+
+static int sprd_drm_remove(struct platform_device *pdev)
+{
+	component_master_del(&pdev->dev, &drm_component_ops);
+	return 0;
+}
+
+static void sprd_drm_shutdown(struct platform_device *pdev)
+{
+	struct drm_device *drm = platform_get_drvdata(pdev);
+
+	if (!drm) {
+		drm_warn(drm, "drm device is not available, no shutdown\n");
+		return;
+	}
+
+	drm_atomic_helper_shutdown(drm);
+}
+
+static const struct of_device_id drm_match_table[] = {
+	{ .compatible = "sprd,display-subsystem", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, drm_match_table);
+
+static struct platform_driver sprd_drm_driver = {
+	.probe = sprd_drm_probe,
+	.remove = sprd_drm_remove,
+	.shutdown = sprd_drm_shutdown,
+	.driver = {
+		.name = "sprd-drm-drv",
+		.of_match_table = drm_match_table,
+	},
+};
+
+static struct platform_driver *sprd_drm_drivers[]  = {
+	&sprd_drm_driver,
+};
+
+static int __init sprd_drm_init(void)
+{
+	return platform_register_drivers(sprd_drm_drivers,
+					ARRAY_SIZE(sprd_drm_drivers));
+}
+
+static void __exit sprd_drm_exit(void)
+{
+	platform_unregister_drivers(sprd_drm_drivers,
+				    ARRAY_SIZE(sprd_drm_drivers));
+}
+
+module_init(sprd_drm_init);
+module_exit(sprd_drm_exit);
+
+MODULE_AUTHOR("Leon He <leon.he@unisoc.com>");
+MODULE_AUTHOR("Kevin Tang <kevin.tang@unisoc.com>");
+MODULE_DESCRIPTION("Unisoc DRM KMS Master Driver");
+MODULE_LICENSE("GPL v2");

drivers/gpu/drm/sprd/sprd_drm.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 Unisoc Inc.
+ */
+
+#ifndef _SPRD_DRM_H_
+#define _SPRD_DRM_H_
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_print.h>
+
+struct sprd_drm {
+	struct drm_device drm;
+};
+
+#endif /* _SPRD_DRM_H_ */