drm/komeda: Build komeda to be a platform module

Implement a simple wrapper for platform module to build komeda to module,
Also add a very simple D71 layer code to show how to discover a product.
Komeda driver direct bind the product ENTRY function xxx_identity to DT
compatible name like:

d71_product = {
	.product_id = MALIDP_D71_PRODUCT_ID,
	.identify = d71_identify,
},

const struct of_device_id komeda_of_match[] = {
	{ .compatible = "arm,mali-d71", .data = &d71_product, },
	{},
};

Then when linux found a matched DT node and call driver to probe, we can
easily get the of data, and call into the product to do the identify:

komeda_bind()
{
    ...
    product = of_device_get_match_data(dev);

    product->identify();
    ...
}

Changes in v4:
- Replaced kzalloc with devm_kzalloc

Changes in v3:
- Fixed style problem found by checkpatch.pl --strict.
Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

drivers/gpu/drm/arm/display/include/malidp_io.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#ifndef _MALIDP_IO_H_
+#define _MALIDP_IO_H_
+
+#include <linux/io.h>
+
+static inline u32
+malidp_read32(u32 __iomem *base, u32 offset)
+{
+	return readl((base + (offset >> 2)));
+}
+
+static inline void
+malidp_write32(u32 __iomem *base, u32 offset, u32 v)
+{
+	writel(v, (base + (offset >> 2)));
+}
+
+static inline void
+malidp_write32_mask(u32 __iomem *base, u32 offset, u32 m, u32 v)
+{
+	u32 tmp = malidp_read32(base, offset);
+
+	tmp &= (~m);
+	malidp_write32(base, offset, v | tmp);
+}
+
+static inline void
+malidp_write_group(u32 __iomem *base, u32 offset, int num, const u32 *values)
+{
+	int i;
+
+	for (i = 0; i < num; i++)
+		malidp_write32(base, offset + i * 4, values[i]);
+}
+
+#endif /*_MALIDP_IO_H_*/

drivers/gpu/drm/arm/display/komeda/Makefile

@@ -5,7 +5,11 @@ ccflags-y := \
 	-I$(src)
 
 komeda-y := \
+	komeda_drv.o \
 	komeda_dev.o \
-	komeda_pipeline.o \
+	komeda_pipeline.o
+
+komeda-y += \
+	d71/d71_dev.o
 
 obj-$(CONFIG_DRM_KOMEDA) += komeda.o

drivers/gpu/drm/arm/display/komeda/d71/d71_dev.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#include "malidp_io.h"
+#include "komeda_dev.h"
+
+static int d71_enum_resources(struct komeda_dev *mdev)
+{
+	/* TODO add enum resources */
+	return -1;
+}
+
+static struct komeda_dev_funcs d71_chip_funcs = {
+	.enum_resources	= d71_enum_resources,
+	.cleanup	= NULL,
+};
+
+#define GLB_ARCH_ID		0x000
+#define GLB_CORE_ID		0x004
+#define GLB_CORE_INFO		0x008
+
+struct komeda_dev_funcs *
+d71_identify(u32 __iomem *reg_base, struct komeda_chip_info *chip)
+{
+	chip->arch_id	= malidp_read32(reg_base, GLB_ARCH_ID);
+	chip->core_id	= malidp_read32(reg_base, GLB_CORE_ID);
+	chip->core_info	= malidp_read32(reg_base, GLB_CORE_INFO);
+
+	return &d71_chip_funcs;
+}

drivers/gpu/drm/arm/display/komeda/komeda_dev.h

@@ -92,6 +92,9 @@ komeda_product_match(struct komeda_dev *mdev, u32 target)
 	return MALIDP_CORE_ID_PRODUCT_ID(mdev->chip.core_id) == target;
 }
 
+struct komeda_dev_funcs *
+d71_identify(u32 __iomem *reg, struct komeda_chip_info *chip);
+
 struct komeda_dev *komeda_dev_create(struct device *dev);
 void komeda_dev_destroy(struct komeda_dev *mdev);
 

drivers/gpu/drm/arm/display/komeda/komeda_drv.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * (C) COPYRIGHT 2018 ARM Limited. All rights reserved.
+ * Author: James.Qian.Wang <james.qian.wang@arm.com>
+ *
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/component.h>
+#include <drm/drm_of.h>
+#include "komeda_dev.h"
+
+struct komeda_drv {
+	struct komeda_dev *mdev;
+};
+
+static void komeda_unbind(struct device *dev)
+{
+	struct komeda_drv *mdrv = dev_get_drvdata(dev);
+
+	if (!mdrv)
+		return;
+
+	komeda_dev_destroy(mdrv->mdev);
+
+	dev_set_drvdata(dev, NULL);
+	devm_kfree(dev, mdrv);
+}
+
+static int komeda_bind(struct device *dev)
+{
+	struct komeda_drv *mdrv;
+	int err;
+
+	mdrv = devm_kzalloc(dev, sizeof(*mdrv), GFP_KERNEL);
+	if (!mdrv)
+		return -ENOMEM;
+
+	mdrv->mdev = komeda_dev_create(dev);
+	if (IS_ERR(mdrv->mdev)) {
+		err = PTR_ERR(mdrv->mdev);
+		goto free_mdrv;
+	}
+
+	dev_set_drvdata(dev, mdrv);
+
+	return 0;
+
+free_mdrv:
+	devm_kfree(dev, mdrv);
+	return err;
+}
+
+static const struct component_master_ops komeda_master_ops = {
+	.bind	= komeda_bind,
+	.unbind	= komeda_unbind,
+};
+
+static int compare_of(struct device *dev, void *data)
+{
+	return dev->of_node == data;
+}
+
+static void komeda_add_slave(struct device *master,
+			     struct component_match **match,
+			     struct device_node *np, int port)
+{
+	struct device_node *remote;
+
+	remote = of_graph_get_remote_node(np, port, 0);
+	if (remote) {
+		drm_of_component_match_add(master, match, compare_of, remote);
+		of_node_put(remote);
+	}
+}
+
+static int komeda_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct component_match *match = NULL;
+	struct device_node *child;
+
+	if (!dev->of_node)
+		return -ENODEV;
+
+	for_each_available_child_of_node(dev->of_node, child) {
+		if (of_node_cmp(child->name, "pipeline") != 0)
+			continue;
+
+		/* add connector */
+		komeda_add_slave(dev, &match, child, KOMEDA_OF_PORT_OUTPUT);
+	}
+
+	return component_master_add_with_match(dev, &komeda_master_ops, match);
+}
+
+static int komeda_platform_remove(struct platform_device *pdev)
+{
+	component_master_del(&pdev->dev, &komeda_master_ops);
+	return 0;
+}
+
+static const struct komeda_product_data komeda_products[] = {
+	[MALI_D71] = {
+		.product_id = MALIDP_D71_PRODUCT_ID,
+		.identify = d71_identify,
+	},
+};
+
+const struct of_device_id komeda_of_match[] = {
+	{ .compatible = "arm,mali-d71", .data = &komeda_products[MALI_D71], },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, komeda_of_match);
+
+static struct platform_driver komeda_platform_driver = {
+	.probe	= komeda_platform_probe,
+	.remove	= komeda_platform_remove,
+	.driver	= {
+		.name = "komeda",
+		.of_match_table	= komeda_of_match,
+		.pm = NULL,
+	},
+};
+
+module_platform_driver(komeda_platform_driver);
+
+MODULE_AUTHOR("James.Qian.Wang <james.qian.wang@arm.com>");
+MODULE_DESCRIPTION("Komeda KMS driver");
+MODULE_LICENSE("GPL v2");