sun4i_dma.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright (C) 2016 NextThing Co
  4 * Copyright (C) 2016-2019 Bootlin
  5 *
  6 * Author: Maxime Ripard <maxime.ripard@bootlin.com>
  7 */
  8
  9#include <linux/device.h>
 10#include <linux/interrupt.h>
 11#include <linux/list.h>
 12#include <linux/mutex.h>
 13#include <linux/spinlock.h>
 14#include <media/videobuf2-dma-contig.h>
 15#include <media/videobuf2-v4l2.h>
 16
 17#include "sun4i_csi.h"
 18
 19struct sun4i_csi_buffer {
 20	struct vb2_v4l2_buffer	vb;
 21	struct list_head	list;
 22};
 23
 24static inline struct sun4i_csi_buffer *
 25vb2_v4l2_to_csi_buffer(const struct vb2_v4l2_buffer *p)
 26{
 27	return container_of(p, struct sun4i_csi_buffer, vb);
 28}
 29
 30static inline struct sun4i_csi_buffer *
 31vb2_to_csi_buffer(const struct vb2_buffer *p)
 32{
 33	return vb2_v4l2_to_csi_buffer(to_vb2_v4l2_buffer(p));
 34}
 35
 36static void sun4i_csi_capture_start(struct sun4i_csi *csi)
 37{
 38	writel(CSI_CPT_CTRL_VIDEO_START, csi->regs + CSI_CPT_CTRL_REG);
 39}
 40
 41static void sun4i_csi_capture_stop(struct sun4i_csi *csi)
 42{
 43	writel(0, csi->regs + CSI_CPT_CTRL_REG);
 44}
 45
 46static int sun4i_csi_queue_setup(struct vb2_queue *vq,
 47				 unsigned int *nbuffers,
 48				 unsigned int *nplanes,
 49				 unsigned int sizes[],
 50				 struct device *alloc_devs[])
 51{
 52	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
 53	unsigned int num_planes = csi->fmt.num_planes;
 54	unsigned int i;
 55
 56	if (*nplanes) {
 57		if (*nplanes != num_planes)
 58			return -EINVAL;
 59
 60		for (i = 0; i < num_planes; i++)
 61			if (sizes[i] < csi->fmt.plane_fmt[i].sizeimage)
 62				return -EINVAL;
 63		return 0;
 64	}
 65
 66	*nplanes = num_planes;
 67	for (i = 0; i < num_planes; i++)
 68		sizes[i] = csi->fmt.plane_fmt[i].sizeimage;
 69
 70	return 0;
 71};
 72
 73static int sun4i_csi_buffer_prepare(struct vb2_buffer *vb)
 74{
 75	struct sun4i_csi *csi = vb2_get_drv_priv(vb->vb2_queue);
 76	unsigned int i;
 77
 78	for (i = 0; i < csi->fmt.num_planes; i++) {
 79		unsigned long size = csi->fmt.plane_fmt[i].sizeimage;
 80
 81		if (vb2_plane_size(vb, i) < size) {
 82			dev_err(csi->dev, "buffer too small (%lu < %lu)\n",
 83				vb2_plane_size(vb, i), size);
 84			return -EINVAL;
 85		}
 86
 87		vb2_set_plane_payload(vb, i, size);
 88	}
 89
 90	return 0;
 91}
 92
 93static int sun4i_csi_setup_scratch_buffer(struct sun4i_csi *csi,
 94					  unsigned int slot)
 95{
 96	dma_addr_t addr = csi->scratch.paddr;
 97	unsigned int plane;
 98
 99	dev_dbg(csi->dev,
100		"No more available buffer, using the scratch buffer\n");
101
102	for (plane = 0; plane < csi->fmt.num_planes; plane++) {
103		writel(addr, csi->regs + CSI_BUF_ADDR_REG(plane, slot));
104		addr += csi->fmt.plane_fmt[plane].sizeimage;
105	}
106
107	csi->current_buf[slot] = NULL;
108	return 0;
109}
110
111static int sun4i_csi_buffer_fill_slot(struct sun4i_csi *csi, unsigned int slot)
112{
113	struct sun4i_csi_buffer *c_buf;
114	struct vb2_v4l2_buffer *v_buf;
115	unsigned int plane;
116
117	/*
118	 * We should never end up in a situation where we overwrite an
119	 * already filled slot.
120	 */
121	if (WARN_ON(csi->current_buf[slot]))
122		return -EINVAL;
123
124	if (list_empty(&csi->buf_list))
125		return sun4i_csi_setup_scratch_buffer(csi, slot);
126
127	c_buf = list_first_entry(&csi->buf_list, struct sun4i_csi_buffer, list);
128	list_del_init(&c_buf->list);
129
130	v_buf = &c_buf->vb;
131	csi->current_buf[slot] = v_buf;
132
133	for (plane = 0; plane < csi->fmt.num_planes; plane++) {
134		dma_addr_t buf_addr;
135
136		buf_addr = vb2_dma_contig_plane_dma_addr(&v_buf->vb2_buf,
137							 plane);
138		writel(buf_addr, csi->regs + CSI_BUF_ADDR_REG(plane, slot));
139	}
140
141	return 0;
142}
143
144static int sun4i_csi_buffer_fill_all(struct sun4i_csi *csi)
145{
146	unsigned int slot;
147	int ret;
148
149	for (slot = 0; slot < CSI_MAX_BUFFER; slot++) {
150		ret = sun4i_csi_buffer_fill_slot(csi, slot);
151		if (ret)
152			return ret;
153	}
154
155	return 0;
156}
157
158static void sun4i_csi_buffer_mark_done(struct sun4i_csi *csi,
159				       unsigned int slot,
160				       unsigned int sequence)
161{
162	struct vb2_v4l2_buffer *v_buf;
163
164	if (!csi->current_buf[slot]) {
165		dev_dbg(csi->dev, "Scratch buffer was used, ignoring..\n");
166		return;
167	}
168
169	v_buf = csi->current_buf[slot];
170	v_buf->field = csi->fmt.field;
171	v_buf->sequence = sequence;
172	v_buf->vb2_buf.timestamp = ktime_get_ns();
173	vb2_buffer_done(&v_buf->vb2_buf, VB2_BUF_STATE_DONE);
174
175	csi->current_buf[slot] = NULL;
176}
177
178static int sun4i_csi_buffer_flip(struct sun4i_csi *csi, unsigned int sequence)
179{
180	u32 reg = readl(csi->regs + CSI_BUF_CTRL_REG);
181	unsigned int next;
182
183	/* Our next buffer is not the current buffer */
184	next = !(reg & CSI_BUF_CTRL_DBS);
185
186	/* Report the previous buffer as done */
187	sun4i_csi_buffer_mark_done(csi, next, sequence);
188
189	/* Put a new buffer in there */
190	return sun4i_csi_buffer_fill_slot(csi, next);
191}
192
193static void sun4i_csi_buffer_queue(struct vb2_buffer *vb)
194{
195	struct sun4i_csi *csi = vb2_get_drv_priv(vb->vb2_queue);
196	struct sun4i_csi_buffer *buf = vb2_to_csi_buffer(vb);
197	unsigned long flags;
198
199	spin_lock_irqsave(&csi->qlock, flags);
200	list_add_tail(&buf->list, &csi->buf_list);
201	spin_unlock_irqrestore(&csi->qlock, flags);
202}
203
204static void return_all_buffers(struct sun4i_csi *csi,
205			       enum vb2_buffer_state state)
206{
207	struct sun4i_csi_buffer *buf, *node;
208	unsigned int slot;
209
210	list_for_each_entry_safe(buf, node, &csi->buf_list, list) {
211		vb2_buffer_done(&buf->vb.vb2_buf, state);
212		list_del(&buf->list);
213	}
214
215	for (slot = 0; slot < CSI_MAX_BUFFER; slot++) {
216		struct vb2_v4l2_buffer *v_buf = csi->current_buf[slot];
217
218		if (!v_buf)
219			continue;
220
221		vb2_buffer_done(&v_buf->vb2_buf, state);
222		csi->current_buf[slot] = NULL;
223	}
224}
225
226static int sun4i_csi_start_streaming(struct vb2_queue *vq, unsigned int count)
227{
228	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
229	struct v4l2_mbus_config_parallel *bus = &csi->bus;
230	const struct sun4i_csi_format *csi_fmt;
231	unsigned long href_pol, pclk_pol, vref_pol;
232	unsigned long flags;
233	unsigned int i;
234	int ret;
235
236	csi_fmt = sun4i_csi_find_format(&csi->fmt.pixelformat, NULL);
237	if (!csi_fmt)
238		return -EINVAL;
239
240	dev_dbg(csi->dev, "Starting capture\n");
241
242	csi->sequence = 0;
243
244	/*
245	 * We need a scratch buffer in case where we'll not have any
246	 * more buffer queued so that we don't error out. One of those
247	 * cases is when you end up at the last frame to capture, you
248	 * don't have any buffer queued any more, and yet it doesn't
249	 * really matter since you'll never reach the next buffer.
250	 *
251	 * Since we support the multi-planar API, we need to have a
252	 * buffer for each plane. Allocating a single one large enough
253	 * to hold all the buffers is simpler, so let's go for that.
254	 */
255	csi->scratch.size = 0;
256	for (i = 0; i < csi->fmt.num_planes; i++)
257		csi->scratch.size += csi->fmt.plane_fmt[i].sizeimage;
258
259	csi->scratch.vaddr = dma_alloc_coherent(csi->dev,
260						csi->scratch.size,
261						&csi->scratch.paddr,
262						GFP_KERNEL);
263	if (!csi->scratch.vaddr) {
264		dev_err(csi->dev, "Failed to allocate scratch buffer\n");
265		ret = -ENOMEM;
266		goto err_clear_dma_queue;
267	}
268
269	ret = video_device_pipeline_alloc_start(&csi->vdev);
270	if (ret < 0)
271		goto err_free_scratch_buffer;
272
273	spin_lock_irqsave(&csi->qlock, flags);
274
275	/* Setup timings */
276	writel(CSI_WIN_CTRL_W_ACTIVE(csi->fmt.width * 2),
277	       csi->regs + CSI_WIN_CTRL_W_REG);
278	writel(CSI_WIN_CTRL_H_ACTIVE(csi->fmt.height),
279	       csi->regs + CSI_WIN_CTRL_H_REG);
280
281	/*
282	 * This hardware uses [HV]REF instead of [HV]SYNC. Based on the
283	 * provided timing diagrams in the manual, positive polarity
284	 * equals active high [HV]REF.
285	 *
286	 * When the back porch is 0, [HV]REF is more or less equivalent
287	 * to [HV]SYNC inverted.
288	 */
289	href_pol = !!(bus->flags & V4L2_MBUS_HSYNC_ACTIVE_LOW);
290	vref_pol = !!(bus->flags & V4L2_MBUS_VSYNC_ACTIVE_LOW);
291	pclk_pol = !!(bus->flags & V4L2_MBUS_PCLK_SAMPLE_RISING);
292	writel(CSI_CFG_INPUT_FMT(csi_fmt->input) |
293	       CSI_CFG_OUTPUT_FMT(csi_fmt->output) |
294	       CSI_CFG_VREF_POL(vref_pol) |
295	       CSI_CFG_HREF_POL(href_pol) |
296	       CSI_CFG_PCLK_POL(pclk_pol),
297	       csi->regs + CSI_CFG_REG);
298
299	/* Setup buffer length */
300	writel(csi->fmt.plane_fmt[0].bytesperline,
301	       csi->regs + CSI_BUF_LEN_REG);
302
303	/* Prepare our buffers in hardware */
304	ret = sun4i_csi_buffer_fill_all(csi);
305	if (ret) {
306		spin_unlock_irqrestore(&csi->qlock, flags);
307		goto err_disable_pipeline;
308	}
309
310	/* Enable double buffering */
311	writel(CSI_BUF_CTRL_DBE, csi->regs + CSI_BUF_CTRL_REG);
312
313	/* Clear the pending interrupts */
314	writel(CSI_INT_FRM_DONE, csi->regs + CSI_INT_STA_REG);
315
316	/* Enable frame done interrupt */
317	writel(CSI_INT_FRM_DONE, csi->regs + CSI_INT_EN_REG);
318
319	sun4i_csi_capture_start(csi);
320
321	spin_unlock_irqrestore(&csi->qlock, flags);
322
323	ret = v4l2_subdev_call(csi->src_subdev, video, s_stream, 1);
324	if (ret < 0 && ret != -ENOIOCTLCMD)
325		goto err_disable_device;
326
327	return 0;
328
329err_disable_device:
330	sun4i_csi_capture_stop(csi);
331
332err_disable_pipeline:
333	video_device_pipeline_stop(&csi->vdev);
334
335err_free_scratch_buffer:
336	dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
337			  csi->scratch.paddr);
338
339err_clear_dma_queue:
340	spin_lock_irqsave(&csi->qlock, flags);
341	return_all_buffers(csi, VB2_BUF_STATE_QUEUED);
342	spin_unlock_irqrestore(&csi->qlock, flags);
343
344	return ret;
345}
346
347static void sun4i_csi_stop_streaming(struct vb2_queue *vq)
348{
349	struct sun4i_csi *csi = vb2_get_drv_priv(vq);
350	unsigned long flags;
351
352	dev_dbg(csi->dev, "Stopping capture\n");
353
354	v4l2_subdev_call(csi->src_subdev, video, s_stream, 0);
355	sun4i_csi_capture_stop(csi);
356
357	/* Release all active buffers */
358	spin_lock_irqsave(&csi->qlock, flags);
359	return_all_buffers(csi, VB2_BUF_STATE_ERROR);
360	spin_unlock_irqrestore(&csi->qlock, flags);
361
362	video_device_pipeline_stop(&csi->vdev);
363
364	dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
365			  csi->scratch.paddr);
366}
367
368static const struct vb2_ops sun4i_csi_qops = {
369	.queue_setup		= sun4i_csi_queue_setup,
370	.buf_prepare		= sun4i_csi_buffer_prepare,
371	.buf_queue		= sun4i_csi_buffer_queue,
372	.start_streaming	= sun4i_csi_start_streaming,
373	.stop_streaming		= sun4i_csi_stop_streaming,
374};
375
376static irqreturn_t sun4i_csi_irq(int irq, void *data)
377{
378	struct sun4i_csi *csi = data;
379	u32 reg;
380
381	reg = readl(csi->regs + CSI_INT_STA_REG);
382
383	/* Acknowledge the interrupts */
384	writel(reg, csi->regs + CSI_INT_STA_REG);
385
386	if (!(reg & CSI_INT_FRM_DONE))
387		return IRQ_HANDLED;
388
389	spin_lock(&csi->qlock);
390	if (sun4i_csi_buffer_flip(csi, csi->sequence++)) {
391		dev_warn(csi->dev, "%s: Flip failed\n", __func__);
392		sun4i_csi_capture_stop(csi);
393	}
394	spin_unlock(&csi->qlock);
395
396	return IRQ_HANDLED;
397}
398
399int sun4i_csi_dma_register(struct sun4i_csi *csi, int irq)
400{
401	struct vb2_queue *q = &csi->queue;
402	int ret;
403	int i;
404
405	spin_lock_init(&csi->qlock);
406	mutex_init(&csi->lock);
407
408	INIT_LIST_HEAD(&csi->buf_list);
409	for (i = 0; i < CSI_MAX_BUFFER; i++)
410		csi->current_buf[i] = NULL;
411
412	q->min_queued_buffers = 3;
413	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
414	q->io_modes = VB2_MMAP | VB2_DMABUF;
415	q->lock = &csi->lock;
416	q->drv_priv = csi;
417	q->buf_struct_size = sizeof(struct sun4i_csi_buffer);
418	q->ops = &sun4i_csi_qops;
419	q->mem_ops = &vb2_dma_contig_memops;
420	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
421	q->dev = csi->dev;
422
423	ret = vb2_queue_init(q);
424	if (ret < 0) {
425		dev_err(csi->dev, "failed to initialize VB2 queue\n");
426		goto err_free_mutex;
427	}
428
429	ret = v4l2_device_register(csi->dev, &csi->v4l);
430	if (ret) {
431		dev_err(csi->dev, "Couldn't register the v4l2 device\n");
432		goto err_free_mutex;
433	}
434
435	ret = devm_request_irq(csi->dev, irq, sun4i_csi_irq, 0,
436			       dev_name(csi->dev), csi);
437	if (ret) {
438		dev_err(csi->dev, "Couldn't register our interrupt\n");
439		goto err_unregister_device;
440	}
441
442	return 0;
443
444err_unregister_device:
445	v4l2_device_unregister(&csi->v4l);
446
447err_free_mutex:
448	mutex_destroy(&csi->lock);
449	return ret;
450}
451
452void sun4i_csi_dma_unregister(struct sun4i_csi *csi)
453{
454	v4l2_device_unregister(&csi->v4l);
455	mutex_destroy(&csi->lock);
456}