soc: amlogic: add meson-canvas driver

Amlogic SoCs have a repository of 256 canvas which they use to
describe pixel buffers.

They contain metadata like width, height, block mode, endianness [..]

Many IPs within those SoCs like vdec/vpu rely on those canvas to read/write
pixels.
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Maxime Jourdan <mjourdan@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>

drivers/soc/amlogic/Kconfig

 menu "Amlogic SoC drivers"
 
+config MESON_CANVAS
+	tristate "Amlogic Meson Canvas driver"
+	depends on ARCH_MESON || COMPILE_TEST
+	default n
+	help
+	  Say yes to support the canvas IP for Amlogic SoCs.
+
 config MESON_GX_SOCINFO
 	bool "Amlogic Meson GX SoC Information driver"
 	depends on ARCH_MESON || COMPILE_TEST

drivers/soc/amlogic/Makefile

+obj-$(CONFIG_MESON_CANVAS) += meson-canvas.o
 obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
 obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
 obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o

drivers/soc/amlogic/meson-canvas.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 BayLibre, SAS
+ * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
+ * Copyright (C) 2014 Endless Mobile
+ */
+
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/soc/amlogic/meson-canvas.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/io.h>
+
+#define NUM_CANVAS 256
+
+/* DMC Registers */
+#define DMC_CAV_LUT_DATAL	0x00
+	#define CANVAS_WIDTH_LBIT	29
+	#define CANVAS_WIDTH_LWID	3
+#define DMC_CAV_LUT_DATAH	0x04
+	#define CANVAS_WIDTH_HBIT	0
+	#define CANVAS_HEIGHT_BIT	9
+	#define CANVAS_WRAP_BIT		22
+	#define CANVAS_BLKMODE_BIT	24
+	#define CANVAS_ENDIAN_BIT	26
+#define DMC_CAV_LUT_ADDR	0x08
+	#define CANVAS_LUT_WR_EN	BIT(9)
+	#define CANVAS_LUT_RD_EN	BIT(8)
+
+struct meson_canvas {
+	struct device *dev;
+	void __iomem *reg_base;
+	spinlock_t lock; /* canvas device lock */
+	u8 used[NUM_CANVAS];
+};
+
+static void canvas_write(struct meson_canvas *canvas, u32 reg, u32 val)
+{
+	writel_relaxed(val, canvas->reg_base + reg);
+}
+
+static u32 canvas_read(struct meson_canvas *canvas, u32 reg)
+{
+	return readl_relaxed(canvas->reg_base + reg);
+}
+
+struct meson_canvas *meson_canvas_get(struct device *dev)
+{
+	struct device_node *canvas_node;
+	struct platform_device *canvas_pdev;
+
+	canvas_node = of_parse_phandle(dev->of_node, "amlogic,canvas", 0);
+	if (!canvas_node)
+		return ERR_PTR(-ENODEV);
+
+	canvas_pdev = of_find_device_by_node(canvas_node);
+	if (!canvas_pdev)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	return dev_get_drvdata(&canvas_pdev->dev);
+}
+EXPORT_SYMBOL_GPL(meson_canvas_get);
+
+int meson_canvas_config(struct meson_canvas *canvas, u8 canvas_index,
+			u32 addr, u32 stride, u32 height,
+			unsigned int wrap,
+			unsigned int blkmode,
+			unsigned int endian)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&canvas->lock, flags);
+	if (!canvas->used[canvas_index]) {
+		dev_err(canvas->dev,
+			"Trying to setup non allocated canvas %u\n",
+			canvas_index);
+		spin_unlock_irqrestore(&canvas->lock, flags);
+		return -EINVAL;
+	}
+
+	canvas_write(canvas, DMC_CAV_LUT_DATAL,
+		     ((addr + 7) >> 3) |
+		     (((stride + 7) >> 3) << CANVAS_WIDTH_LBIT));
+
+	canvas_write(canvas, DMC_CAV_LUT_DATAH,
+		     ((((stride + 7) >> 3) >> CANVAS_WIDTH_LWID) <<
+						CANVAS_WIDTH_HBIT) |
+		     (height << CANVAS_HEIGHT_BIT) |
+		     (wrap << CANVAS_WRAP_BIT) |
+		     (blkmode << CANVAS_BLKMODE_BIT) |
+		     (endian << CANVAS_ENDIAN_BIT));
+
+	canvas_write(canvas, DMC_CAV_LUT_ADDR,
+		     CANVAS_LUT_WR_EN | canvas_index);
+
+	/* Force a read-back to make sure everything is flushed. */
+	canvas_read(canvas, DMC_CAV_LUT_DATAH);
+	spin_unlock_irqrestore(&canvas->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(meson_canvas_config);
+
+int meson_canvas_alloc(struct meson_canvas *canvas, u8 *canvas_index)
+{
+	int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&canvas->lock, flags);
+	for (i = 0; i < NUM_CANVAS; ++i) {
+		if (!canvas->used[i]) {
+			canvas->used[i] = 1;
+			spin_unlock_irqrestore(&canvas->lock, flags);
+			*canvas_index = i;
+			return 0;
+		}
+	}
+	spin_unlock_irqrestore(&canvas->lock, flags);
+
+	dev_err(canvas->dev, "No more canvas available\n");
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(meson_canvas_alloc);
+
+int meson_canvas_free(struct meson_canvas *canvas, u8 canvas_index)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&canvas->lock, flags);
+	if (!canvas->used[canvas_index]) {
+		dev_err(canvas->dev,
+			"Trying to free unused canvas %u\n", canvas_index);
+		spin_unlock_irqrestore(&canvas->lock, flags);
+		return -EINVAL;
+	}
+	canvas->used[canvas_index] = 0;
+	spin_unlock_irqrestore(&canvas->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(meson_canvas_free);
+
+static int meson_canvas_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct meson_canvas *canvas;
+	struct device *dev = &pdev->dev;
+
+	canvas = devm_kzalloc(dev, sizeof(*canvas), GFP_KERNEL);
+	if (!canvas)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	canvas->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(canvas->reg_base))
+		return PTR_ERR(canvas->reg_base);
+
+	canvas->dev = dev;
+	spin_lock_init(&canvas->lock);
+	dev_set_drvdata(dev, canvas);
+
+	return 0;
+}
+
+static const struct of_device_id canvas_dt_match[] = {
+	{ .compatible = "amlogic,canvas" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, canvas_dt_match);
+
+static struct platform_driver meson_canvas_driver = {
+	.probe = meson_canvas_probe,
+	.driver = {
+		.name = "amlogic-canvas",
+		.of_match_table = canvas_dt_match,
+	},
+};
+module_platform_driver(meson_canvas_driver);
+
+MODULE_DESCRIPTION("Amlogic Canvas driver");
+MODULE_AUTHOR("Maxime Jourdan <mjourdan@baylibre.com>");
+MODULE_LICENSE("GPL");

include/linux/soc/amlogic/meson-canvas.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018 BayLibre, SAS
+ */
+#ifndef __SOC_MESON_CANVAS_H
+#define __SOC_MESON_CANVAS_H
+
+#include <linux/kernel.h>
+
+#define MESON_CANVAS_WRAP_NONE	0x00
+#define MESON_CANVAS_WRAP_X	0x01
+#define MESON_CANVAS_WRAP_Y	0x02
+
+#define MESON_CANVAS_BLKMODE_LINEAR	0x00
+#define MESON_CANVAS_BLKMODE_32x32	0x01
+#define MESON_CANVAS_BLKMODE_64x64	0x02
+
+#define MESON_CANVAS_ENDIAN_SWAP16	0x1
+#define MESON_CANVAS_ENDIAN_SWAP32	0x3
+#define MESON_CANVAS_ENDIAN_SWAP64	0x7
+#define MESON_CANVAS_ENDIAN_SWAP128	0xf
+
+struct meson_canvas;
+
+/**
+ * meson_canvas_get() - get a canvas provider instance
+ *
+ * @dev: consumer device pointer
+ */
+struct meson_canvas *meson_canvas_get(struct device *dev);
+
+/**
+ * meson_canvas_alloc() - take ownership of a canvas
+ *
+ * @canvas: canvas provider instance retrieved from meson_canvas_get()
+ * @canvas_index: will be filled with the canvas ID
+ */
+int meson_canvas_alloc(struct meson_canvas *canvas, u8 *canvas_index);
+
+/**
+ * meson_canvas_free() - remove ownership from a canvas
+ *
+ * @canvas: canvas provider instance retrieved from meson_canvas_get()
+ * @canvas_index: canvas ID that was obtained via meson_canvas_alloc()
+ */
+int meson_canvas_free(struct meson_canvas *canvas, u8 canvas_index);
+
+/**
+ * meson_canvas_config() - configure a canvas
+ *
+ * @canvas: canvas provider instance retrieved from meson_canvas_get()
+ * @canvas_index: canvas ID that was obtained via meson_canvas_alloc()
+ * @addr: physical address to the pixel buffer
+ * @stride: width of the buffer
+ * @height: height of the buffer
+ * @wrap: undocumented
+ * @blkmode: block mode (linear, 32x32, 64x64)
+ * @endian: byte swapping (swap16, swap32, swap64, swap128)
+ */
+int meson_canvas_config(struct meson_canvas *canvas, u8 canvas_index,
+			u32 addr, u32 stride, u32 height,
+			unsigned int wrap, unsigned int blkmode,
+			unsigned int endian);
+
+#endif