media: sunxi: Add A10 CSI driver

The older CSI drivers have camera capture interface different from the one
in the newer ones.

This IP is pretty simple. Some variants (one controller out of two
instances on some SoCs) have an ISP embedded, but there's no code that make
use of it, so we ignored that part for now.

[Sakari Ailus: Wrapped a few long lines, set mbus code using a macro.]

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 454 insertions, 0 deletions

diff --git a/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c b/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c
new file mode 100644
index 000000000000..d6979e11a67b
--- /dev/null
+++ b/drivers/media/platform/sunxi/sun4i-csi/sun4i_dma.c
@@ -0,0 +1,454 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 NextThing Co
+ * Copyright (C) 2016-2019 Bootlin
+ *
+ * Author: Maxime Ripard <maxime.ripard@bootlin.com>
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <media/videobuf2-dma-contig.h>
+#include <media/videobuf2-v4l2.h>
+
+#include "sun4i_csi.h"
+
+struct sun4i_csi_buffer {
+	struct vb2_v4l2_buffer	vb;
+	struct list_head	list;
+};
+
+static inline struct sun4i_csi_buffer *
+vb2_v4l2_to_csi_buffer(const struct vb2_v4l2_buffer *p)
+{
+	return container_of(p, struct sun4i_csi_buffer, vb);
+}
+
+static inline struct sun4i_csi_buffer *
+vb2_to_csi_buffer(const struct vb2_buffer *p)
+{
+	return vb2_v4l2_to_csi_buffer(to_vb2_v4l2_buffer(p));
+}
+
+static void sun4i_csi_capture_start(struct sun4i_csi *csi)
+{
+	writel(CSI_CPT_CTRL_VIDEO_START, csi->regs + CSI_CPT_CTRL_REG);
+}
+
+static void sun4i_csi_capture_stop(struct sun4i_csi *csi)
+{
+	writel(0, csi->regs + CSI_CPT_CTRL_REG);
+}
+
+static int sun4i_csi_queue_setup(struct vb2_queue *vq,
+				 unsigned int *nbuffers,
+				 unsigned int *nplanes,
+				 unsigned int sizes[],
+				 struct device *alloc_devs[])
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+	unsigned int num_planes = csi->fmt.num_planes;
+	unsigned int i;
+
+	if (*nplanes) {
+		if (*nplanes != num_planes)
+			return -EINVAL;
+
+		for (i = 0; i < num_planes; i++)
+			if (sizes[i] < csi->fmt.plane_fmt[i].sizeimage)
+				return -EINVAL;
+		return 0;
+	}
+
+	*nplanes = num_planes;
+	for (i = 0; i < num_planes; i++)
+		sizes[i] = csi->fmt.plane_fmt[i].sizeimage;
+
+	return 0;
+};
+
+static int sun4i_csi_buffer_prepare(struct vb2_buffer *vb)
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned int i;
+
+	for (i = 0; i < csi->fmt.num_planes; i++) {
+		unsigned long size = csi->fmt.plane_fmt[i].sizeimage;
+
+		if (vb2_plane_size(vb, i) < size) {
+			dev_err(csi->dev, "buffer too small (%lu < %lu)\n",
+				vb2_plane_size(vb, i), size);
+			return -EINVAL;
+		}
+
+		vb2_set_plane_payload(vb, i, size);
+	}
+
+	return 0;
+}
+
+static int sun4i_csi_setup_scratch_buffer(struct sun4i_csi *csi,
+					  unsigned int slot)
+{
+	dma_addr_t addr = csi->scratch.paddr;
+	unsigned int plane;
+
+	dev_dbg(csi->dev,
+		"No more available buffer, using the scratch buffer\n");
+
+	for (plane = 0; plane < csi->fmt.num_planes; plane++) {
+		writel(addr, csi->regs + CSI_BUF_ADDR_REG(plane, slot));
+		addr += csi->fmt.plane_fmt[plane].sizeimage;
+	}
+
+	csi->current_buf[slot] = NULL;
+	return 0;
+}
+
+static int sun4i_csi_buffer_fill_slot(struct sun4i_csi *csi, unsigned int slot)
+{
+	struct sun4i_csi_buffer *c_buf;
+	struct vb2_v4l2_buffer *v_buf;
+	unsigned int plane;
+
+	/*
+	 * We should never end up in a situation where we overwrite an
+	 * already filled slot.
+	 */
+	if (WARN_ON(csi->current_buf[slot]))
+		return -EINVAL;
+
+	if (list_empty(&csi->buf_list))
+		return sun4i_csi_setup_scratch_buffer(csi, slot);
+
+	c_buf = list_first_entry(&csi->buf_list, struct sun4i_csi_buffer, list);
+	list_del_init(&c_buf->list);
+
+	v_buf = &c_buf->vb;
+	csi->current_buf[slot] = v_buf;
+
+	for (plane = 0; plane < csi->fmt.num_planes; plane++) {
+		dma_addr_t buf_addr;
+
+		buf_addr = vb2_dma_contig_plane_dma_addr(&v_buf->vb2_buf,
+							 plane);
+		writel(buf_addr, csi->regs + CSI_BUF_ADDR_REG(plane, slot));
+	}
+
+	return 0;
+}
+
+static int sun4i_csi_buffer_fill_all(struct sun4i_csi *csi)
+{
+	unsigned int slot;
+	int ret;
+
+	for (slot = 0; slot < CSI_MAX_BUFFER; slot++) {
+		ret = sun4i_csi_buffer_fill_slot(csi, slot);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void sun4i_csi_buffer_mark_done(struct sun4i_csi *csi,
+				       unsigned int slot,
+				       unsigned int sequence)
+{
+	struct vb2_v4l2_buffer *v_buf;
+
+	if (!csi->current_buf[slot]) {
+		dev_dbg(csi->dev, "Scratch buffer was used, ignoring..\n");
+		return;
+	}
+
+	v_buf = csi->current_buf[slot];
+	v_buf->field = csi->fmt.field;
+	v_buf->sequence = sequence;
+	v_buf->vb2_buf.timestamp = ktime_get_ns();
+	vb2_buffer_done(&v_buf->vb2_buf, VB2_BUF_STATE_DONE);
+
+	csi->current_buf[slot] = NULL;
+}
+
+static int sun4i_csi_buffer_flip(struct sun4i_csi *csi, unsigned int sequence)
+{
+	u32 reg = readl(csi->regs + CSI_BUF_CTRL_REG);
+	unsigned int next;
+
+	/* Our next buffer is not the current buffer */
+	next = !(reg & CSI_BUF_CTRL_DBS);
+
+	/* Report the previous buffer as done */
+	sun4i_csi_buffer_mark_done(csi, next, sequence);
+
+	/* Put a new buffer in there */
+	return sun4i_csi_buffer_fill_slot(csi, next);
+}
+
+static void sun4i_csi_buffer_queue(struct vb2_buffer *vb)
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vb->vb2_queue);
+	struct sun4i_csi_buffer *buf = vb2_to_csi_buffer(vb);
+	unsigned long flags;
+
+	spin_lock_irqsave(&csi->qlock, flags);
+	list_add_tail(&buf->list, &csi->buf_list);
+	spin_unlock_irqrestore(&csi->qlock, flags);
+}
+
+static void return_all_buffers(struct sun4i_csi *csi,
+			       enum vb2_buffer_state state)
+{
+	struct sun4i_csi_buffer *buf, *node;
+	unsigned int slot;
+
+	list_for_each_entry_safe(buf, node, &csi->buf_list, list) {
+		vb2_buffer_done(&buf->vb.vb2_buf, state);
+		list_del(&buf->list);
+	}
+
+	for (slot = 0; slot < CSI_MAX_BUFFER; slot++) {
+		struct vb2_v4l2_buffer *v_buf = csi->current_buf[slot];
+
+		if (!v_buf)
+			continue;
+
+		vb2_buffer_done(&v_buf->vb2_buf, state);
+		csi->current_buf[slot] = NULL;
+	}
+}
+
+static int sun4i_csi_start_streaming(struct vb2_queue *vq, unsigned int count)
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+	struct v4l2_fwnode_bus_parallel *bus = &csi->bus;
+	const struct sun4i_csi_format *csi_fmt;
+	unsigned long hsync_pol, pclk_pol, vsync_pol;
+	unsigned long flags;
+	unsigned int i;
+	int ret;
+
+	csi_fmt = sun4i_csi_find_format(&csi->fmt.pixelformat, NULL);
+	if (!csi_fmt)
+		return -EINVAL;
+
+	dev_dbg(csi->dev, "Starting capture\n");
+
+	csi->sequence = 0;
+
+	/*
+	 * We need a scratch buffer in case where we'll not have any
+	 * more buffer queued so that we don't error out. One of those
+	 * cases is when you end up at the last frame to capture, you
+	 * don't havea any buffer queued any more, and yet it doesn't
+	 * really matter since you'll never reach the next buffer.
+	 *
+	 * Since we support the multi-planar API, we need to have a
+	 * buffer for each plane. Allocating a single one large enough
+	 * to hold all the buffers is simpler, so let's go for that.
+	 */
+	csi->scratch.size = 0;
+	for (i = 0; i < csi->fmt.num_planes; i++)
+		csi->scratch.size += csi->fmt.plane_fmt[i].sizeimage;
+
+	csi->scratch.vaddr = dma_alloc_coherent(csi->dev,
+						csi->scratch.size,
+						&csi->scratch.paddr,
+						GFP_KERNEL);
+	if (!csi->scratch.vaddr) {
+		dev_err(csi->dev, "Failed to allocate scratch buffer\n");
+		ret = -ENOMEM;
+		goto err_clear_dma_queue;
+	}
+
+	ret = media_pipeline_start(&csi->vdev.entity, &csi->vdev.pipe);
+	if (ret < 0)
+		goto err_free_scratch_buffer;
+
+	spin_lock_irqsave(&csi->qlock, flags);
+
+	/* Setup timings */
+	writel(CSI_WIN_CTRL_W_ACTIVE(csi->fmt.width * 2),
+	       csi->regs + CSI_WIN_CTRL_W_REG);
+	writel(CSI_WIN_CTRL_H_ACTIVE(csi->fmt.height),
+	       csi->regs + CSI_WIN_CTRL_H_REG);
+
+	hsync_pol = !!(bus->flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH);
+	pclk_pol = !!(bus->flags & V4L2_MBUS_DATA_ACTIVE_HIGH);
+	vsync_pol = !!(bus->flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH);
+	writel(CSI_CFG_INPUT_FMT(csi_fmt->input) |
+	       CSI_CFG_OUTPUT_FMT(csi_fmt->output) |
+	       CSI_CFG_VSYNC_POL(vsync_pol) |
+	       CSI_CFG_HSYNC_POL(hsync_pol) |
+	       CSI_CFG_PCLK_POL(pclk_pol),
+	       csi->regs + CSI_CFG_REG);
+
+	/* Setup buffer length */
+	writel(csi->fmt.plane_fmt[0].bytesperline,
+	       csi->regs + CSI_BUF_LEN_REG);
+
+	/* Prepare our buffers in hardware */
+	ret = sun4i_csi_buffer_fill_all(csi);
+	if (ret) {
+		spin_unlock_irqrestore(&csi->qlock, flags);
+		goto err_disable_pipeline;
+	}
+
+	/* Enable double buffering */
+	writel(CSI_BUF_CTRL_DBE, csi->regs + CSI_BUF_CTRL_REG);
+
+	/* Clear the pending interrupts */
+	writel(CSI_INT_FRM_DONE, csi->regs + 0x34);
+
+	/* Enable frame done interrupt */
+	writel(CSI_INT_FRM_DONE, csi->regs + CSI_INT_EN_REG);
+
+	sun4i_csi_capture_start(csi);
+
+	spin_unlock_irqrestore(&csi->qlock, flags);
+
+	ret = v4l2_subdev_call(csi->src_subdev, video, s_stream, 1);
+	if (ret < 0 && ret != -ENOIOCTLCMD)
+		goto err_disable_device;
+
+	return 0;
+
+err_disable_device:
+	sun4i_csi_capture_stop(csi);
+
+err_disable_pipeline:
+	media_pipeline_stop(&csi->vdev.entity);
+
+err_free_scratch_buffer:
+	dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
+			  csi->scratch.paddr);
+
+err_clear_dma_queue:
+	spin_lock_irqsave(&csi->qlock, flags);
+	return_all_buffers(csi, VB2_BUF_STATE_QUEUED);
+	spin_unlock_irqrestore(&csi->qlock, flags);
+
+	return ret;
+}
+
+static void sun4i_csi_stop_streaming(struct vb2_queue *vq)
+{
+	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
+	unsigned long flags;
+
+	dev_dbg(csi->dev, "Stopping capture\n");
+
+	v4l2_subdev_call(csi->src_subdev, video, s_stream, 0);
+	sun4i_csi_capture_stop(csi);
+
+	/* Release all active buffers */
+	spin_lock_irqsave(&csi->qlock, flags);
+	return_all_buffers(csi, VB2_BUF_STATE_ERROR);
+	spin_unlock_irqrestore(&csi->qlock, flags);
+
+	media_pipeline_stop(&csi->vdev.entity);
+
+	dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
+			  csi->scratch.paddr);
+}
+
+static const struct vb2_ops sun4i_csi_qops = {
+	.queue_setup		= sun4i_csi_queue_setup,
+	.buf_prepare		= sun4i_csi_buffer_prepare,
+	.buf_queue		= sun4i_csi_buffer_queue,
+	.start_streaming	= sun4i_csi_start_streaming,
+	.stop_streaming		= sun4i_csi_stop_streaming,
+	.wait_prepare		= vb2_ops_wait_prepare,
+	.wait_finish		= vb2_ops_wait_finish,
+};
+
+static irqreturn_t sun4i_csi_irq(int irq, void *data)
+{
+	struct sun4i_csi *csi = data;
+	u32 reg;
+
+	reg = readl(csi->regs + CSI_INT_STA_REG);
+
+	/* Acknowledge the interrupts */
+	writel(reg, csi->regs + CSI_INT_STA_REG);
+
+	if (!(reg & CSI_INT_FRM_DONE))
+		return IRQ_HANDLED;
+
+	spin_lock(&csi->qlock);
+	if (sun4i_csi_buffer_flip(csi, csi->sequence++)) {
+		dev_warn(csi->dev, "%s: Flip failed\n", __func__);
+		sun4i_csi_capture_stop(csi);
+	}
+	spin_unlock(&csi->qlock);
+
+	return IRQ_HANDLED;
+}
+
+int sun4i_csi_dma_register(struct sun4i_csi *csi, int irq)
+{
+	struct vb2_queue *q = &csi->queue;
+	int ret;
+	int i;
+
+	spin_lock_init(&csi->qlock);
+	mutex_init(&csi->lock);
+
+	INIT_LIST_HEAD(&csi->buf_list);
+	for (i = 0; i < CSI_MAX_BUFFER; i++)
+		csi->current_buf[i] = NULL;
+
+	q->min_buffers_needed = 3;
+	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+	q->io_modes = VB2_MMAP;
+	q->lock = &csi->lock;
+	q->drv_priv = csi;
+	q->buf_struct_size = sizeof(struct sun4i_csi_buffer);
+	q->ops = &sun4i_csi_qops;
+	q->mem_ops = &vb2_dma_contig_memops;
+	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
+	q->dev = csi->dev;
+
+	ret = vb2_queue_init(q);
+	if (ret < 0) {
+		dev_err(csi->dev, "failed to initialize VB2 queue\n");
+		goto err_free_mutex;
+	}
+
+	ret = v4l2_device_register(csi->dev, &csi->v4l);
+	if (ret) {
+		dev_err(csi->dev, "Couldn't register the v4l2 device\n");
+		goto err_free_queue;
+	}
+
+	ret = devm_request_irq(csi->dev, irq, sun4i_csi_irq, 0,
+			       dev_name(csi->dev), csi);
+	if (ret) {
+		dev_err(csi->dev, "Couldn't register our interrupt\n");
+		goto err_unregister_device;
+	}
+
+	return 0;
+
+err_unregister_device:
+	v4l2_device_unregister(&csi->v4l);
+
+err_free_queue:
+	vb2_queue_release(q);
+
+err_free_mutex:
+	mutex_destroy(&csi->lock);
+	return ret;
+}
+
+void sun4i_csi_dma_unregister(struct sun4i_csi *csi)
+{
+	v4l2_device_unregister(&csi->v4l);
+	vb2_queue_release(&csi->queue);
+	mutex_destroy(&csi->lock);
+}