media: platform: Add Cedrus VPU decoder driver

This introduces the Cedrus VPU driver that supports the VPU found in
Allwinner SoCs, also known as Video Engine. It is implemented through
a V4L2 M2M decoder device and a media device (used for media requests).
So far, it only supports MPEG-2 decoding.

Since this VPU is stateless, synchronization with media requests is
required in order to ensure consistency between frame headers that
contain metadata about the frame to process and the raw slice data that
is used to generate the frame.

This driver was made possible thanks to the long-standing effort
carried out by the linux-sunxi community in the interest of reverse
engineering, documenting and implementing support for the Allwinner VPU.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
[hans.verkuil@cisco.com: dropped obsolete MEDIA_REQUEST_API from Kconfig]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 327 insertions, 0 deletions

diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_hw.c b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
new file mode 100644
index 000000000000..32adbcbe6175
--- /dev/null
+++ b/drivers/staging/media/sunxi/cedrus/cedrus_hw.c
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cedrus VPU driver
+ *
+ * Copyright (C) 2016 Florent Revest <florent.revest@free-electrons.com>
+ * Copyright (C) 2018 Paul Kocialkowski <paul.kocialkowski@bootlin.com>
+ * Copyright (C) 2018 Bootlin
+ *
+ * Based on the vim2m driver, that is:
+ *
+ * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
+ * Pawel Osciak, <pawel@osciak.com>
+ * Marek Szyprowski, <m.szyprowski@samsung.com>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/of_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/soc/sunxi/sunxi_sram.h>
+
+#include <media/videobuf2-core.h>
+#include <media/v4l2-mem2mem.h>
+
+#include "cedrus.h"
+#include "cedrus_hw.h"
+#include "cedrus_regs.h"
+
+int cedrus_engine_enable(struct cedrus_dev *dev, enum cedrus_codec codec)
+{
+	u32 reg = 0;
+
+	/*
+	 * FIXME: This is only valid on 32-bits DDR's, we should test
+	 * it on the A13/A33.
+	 */
+	reg |= VE_MODE_REC_WR_MODE_2MB;
+	reg |= VE_MODE_DDR_MODE_BW_128;
+
+	switch (codec) {
+	case CEDRUS_CODEC_MPEG2:
+		reg |= VE_MODE_DEC_MPEG;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	cedrus_write(dev, VE_MODE, reg);
+
+	return 0;
+}
+
+void cedrus_engine_disable(struct cedrus_dev *dev)
+{
+	cedrus_write(dev, VE_MODE, VE_MODE_DISABLED);
+}
+
+void cedrus_dst_format_set(struct cedrus_dev *dev,
+			   struct v4l2_pix_format *fmt)
+{
+	unsigned int width = fmt->width;
+	unsigned int height = fmt->height;
+	u32 chroma_size;
+	u32 reg;
+
+	switch (fmt->pixelformat) {
+	case V4L2_PIX_FMT_NV12:
+		chroma_size = ALIGN(width, 16) * ALIGN(height, 16) / 2;
+
+		reg = VE_PRIMARY_OUT_FMT_NV12;
+		cedrus_write(dev, VE_PRIMARY_OUT_FMT, reg);
+
+		reg = VE_CHROMA_BUF_LEN_SDRT(chroma_size / 2);
+		cedrus_write(dev, VE_CHROMA_BUF_LEN, reg);
+
+		reg = chroma_size / 2;
+		cedrus_write(dev, VE_PRIMARY_CHROMA_BUF_LEN, reg);
+
+		reg = VE_PRIMARY_FB_LINE_STRIDE_LUMA(ALIGN(width, 16)) |
+		      VE_PRIMARY_FB_LINE_STRIDE_CHROMA(ALIGN(width, 16) / 2);
+		cedrus_write(dev, VE_PRIMARY_FB_LINE_STRIDE, reg);
+
+		break;
+	case V4L2_PIX_FMT_SUNXI_TILED_NV12:
+	default:
+		reg = VE_PRIMARY_OUT_FMT_TILED_32_NV12;
+		cedrus_write(dev, VE_PRIMARY_OUT_FMT, reg);
+
+		reg = VE_SECONDARY_OUT_FMT_TILED_32_NV12;
+		cedrus_write(dev, VE_CHROMA_BUF_LEN, reg);
+
+		break;
+	}
+}
+
+static irqreturn_t cedrus_bh(int irq, void *data)
+{
+	struct cedrus_dev *dev = data;
+	struct cedrus_ctx *ctx;
+
+	ctx = v4l2_m2m_get_curr_priv(dev->m2m_dev);
+	if (!ctx) {
+		v4l2_err(&dev->v4l2_dev,
+			 "Instance released before the end of transaction\n");
+		return IRQ_HANDLED;
+	}
+
+	v4l2_m2m_job_finish(ctx->dev->m2m_dev, ctx->fh.m2m_ctx);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t cedrus_irq(int irq, void *data)
+{
+	struct cedrus_dev *dev = data;
+	struct cedrus_ctx *ctx;
+	struct vb2_v4l2_buffer *src_buf, *dst_buf;
+	enum vb2_buffer_state state;
+	enum cedrus_irq_status status;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->irq_lock, flags);
+
+	ctx = v4l2_m2m_get_curr_priv(dev->m2m_dev);
+	if (!ctx) {
+		v4l2_err(&dev->v4l2_dev,
+			 "Instance released before the end of transaction\n");
+		spin_unlock_irqrestore(&dev->irq_lock, flags);
+
+		return IRQ_NONE;
+	}
+
+	status = dev->dec_ops[ctx->current_codec]->irq_status(ctx);
+	if (status == CEDRUS_IRQ_NONE) {
+		spin_unlock_irqrestore(&dev->irq_lock, flags);
+		return IRQ_NONE;
+	}
+
+	dev->dec_ops[ctx->current_codec]->irq_disable(ctx);
+	dev->dec_ops[ctx->current_codec]->irq_clear(ctx);
+
+	src_buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
+	dst_buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
+
+	if (!src_buf || !dst_buf) {
+		v4l2_err(&dev->v4l2_dev,
+			 "Missing source and/or destination buffers\n");
+		spin_unlock_irqrestore(&dev->irq_lock, flags);
+
+		return IRQ_HANDLED;
+	}
+
+	if (status == CEDRUS_IRQ_ERROR)
+		state = VB2_BUF_STATE_ERROR;
+	else
+		state = VB2_BUF_STATE_DONE;
+
+	v4l2_m2m_buf_done(src_buf, state);
+	v4l2_m2m_buf_done(dst_buf, state);
+
+	spin_unlock_irqrestore(&dev->irq_lock, flags);
+
+	return IRQ_WAKE_THREAD;
+}
+
+int cedrus_hw_probe(struct cedrus_dev *dev)
+{
+	const struct cedrus_variant *variant;
+	struct resource *res;
+	int irq_dec;
+	int ret;
+
+	variant = of_device_get_match_data(dev->dev);
+	if (!variant)
+		return -EINVAL;
+
+	dev->capabilities = variant->capabilities;
+
+	irq_dec = platform_get_irq(dev->pdev, 0);
+	if (irq_dec <= 0) {
+		v4l2_err(&dev->v4l2_dev, "Failed to get IRQ\n");
+
+		return irq_dec;
+	}
+	ret = devm_request_threaded_irq(dev->dev, irq_dec, cedrus_irq,
+					cedrus_bh, 0, dev_name(dev->dev),
+					dev);
+	if (ret) {
+		v4l2_err(&dev->v4l2_dev, "Failed to request IRQ\n");
+
+		return ret;
+	}
+
+	/*
+	 * The VPU is only able to handle bus addresses so we have to subtract
+	 * the RAM offset to the physcal addresses.
+	 *
+	 * This information will eventually be obtained from device-tree.
+	 */
+
+#ifdef PHYS_PFN_OFFSET
+	dev->dev->dma_pfn_offset = PHYS_PFN_OFFSET;
+#endif
+
+	ret = of_reserved_mem_device_init(dev->dev);
+	if (ret && ret != -ENODEV) {
+		v4l2_err(&dev->v4l2_dev, "Failed to reserve memory\n");
+
+		return ret;
+	}
+
+	ret = sunxi_sram_claim(dev->dev);
+	if (ret) {
+		v4l2_err(&dev->v4l2_dev, "Failed to claim SRAM\n");
+
+		goto err_mem;
+	}
+
+	dev->ahb_clk = devm_clk_get(dev->dev, "ahb");
+	if (IS_ERR(dev->ahb_clk)) {
+		v4l2_err(&dev->v4l2_dev, "Failed to get AHB clock\n");
+
+		ret = PTR_ERR(dev->ahb_clk);
+		goto err_sram;
+	}
+
+	dev->mod_clk = devm_clk_get(dev->dev, "mod");
+	if (IS_ERR(dev->mod_clk)) {
+		v4l2_err(&dev->v4l2_dev, "Failed to get MOD clock\n");
+
+		ret = PTR_ERR(dev->mod_clk);
+		goto err_sram;
+	}
+
+	dev->ram_clk = devm_clk_get(dev->dev, "ram");
+	if (IS_ERR(dev->ram_clk)) {
+		v4l2_err(&dev->v4l2_dev, "Failed to get RAM clock\n");
+
+		ret = PTR_ERR(dev->ram_clk);
+		goto err_sram;
+	}
+
+	dev->rstc = devm_reset_control_get(dev->dev, NULL);
+	if (IS_ERR(dev->rstc)) {
+		v4l2_err(&dev->v4l2_dev, "Failed to get reset control\n");
+
+		ret = PTR_ERR(dev->rstc);
+		goto err_sram;
+	}
+
+	res = platform_get_resource(dev->pdev, IORESOURCE_MEM, 0);
+	dev->base = devm_ioremap_resource(dev->dev, res);
+	if (!dev->base) {
+		v4l2_err(&dev->v4l2_dev, "Failed to map registers\n");
+
+		ret = -ENOMEM;
+		goto err_sram;
+	}
+
+	ret = clk_set_rate(dev->mod_clk, CEDRUS_CLOCK_RATE_DEFAULT);
+	if (ret) {
+		v4l2_err(&dev->v4l2_dev, "Failed to set clock rate\n");
+
+		goto err_sram;
+	}
+
+	ret = clk_prepare_enable(dev->ahb_clk);
+	if (ret) {
+		v4l2_err(&dev->v4l2_dev, "Failed to enable AHB clock\n");
+
+		goto err_sram;
+	}
+
+	ret = clk_prepare_enable(dev->mod_clk);
+	if (ret) {
+		v4l2_err(&dev->v4l2_dev, "Failed to enable MOD clock\n");
+
+		goto err_ahb_clk;
+	}
+
+	ret = clk_prepare_enable(dev->ram_clk);
+	if (ret) {
+		v4l2_err(&dev->v4l2_dev, "Failed to enable RAM clock\n");
+
+		goto err_mod_clk;
+	}
+
+	ret = reset_control_reset(dev->rstc);
+	if (ret) {
+		v4l2_err(&dev->v4l2_dev, "Failed to apply reset\n");
+
+		goto err_ram_clk;
+	}
+
+	return 0;
+
+err_ram_clk:
+	clk_disable_unprepare(dev->ram_clk);
+err_mod_clk:
+	clk_disable_unprepare(dev->mod_clk);
+err_ahb_clk:
+	clk_disable_unprepare(dev->ahb_clk);
+err_sram:
+	sunxi_sram_release(dev->dev);
+err_mem:
+	of_reserved_mem_device_release(dev->dev);
+
+	return ret;
+}
+
+void cedrus_hw_remove(struct cedrus_dev *dev)
+{
+	reset_control_assert(dev->rstc);
+
+	clk_disable_unprepare(dev->ram_clk);
+	clk_disable_unprepare(dev->mod_clk);
+	clk_disable_unprepare(dev->ahb_clk);
+
+	sunxi_sram_release(dev->dev);
+
+	of_reserved_mem_device_release(dev->dev);
+}