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 
19 struct sun4i_csi_buffer {
20 	struct vb2_v4l2_buffer	vb;
21 	struct list_head	list;
22 };
23 
24 static inline struct sun4i_csi_buffer *
25 vb2_v4l2_to_csi_buffer(const struct vb2_v4l2_buffer *p)
26 {
27 	return container_of(p, struct sun4i_csi_buffer, vb);
28 }
29 
30 static inline struct sun4i_csi_buffer *
31 vb2_to_csi_buffer(const struct vb2_buffer *p)
32 {
33 	return vb2_v4l2_to_csi_buffer(to_vb2_v4l2_buffer(p));
34 }
35 
36 static 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 
41 static void sun4i_csi_capture_stop(struct sun4i_csi *csi)
42 {
43 	writel(0, csi->regs + CSI_CPT_CTRL_REG);
44 }
45 
46 static 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 
73 static 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 
93 static 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 
111 static 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 
144 static 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 
158 static 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 
178 static 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 
193 static 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 
204 static 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 
226 static 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 havea 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 = media_pipeline_start(&csi->vdev.entity, &csi->vdev.pipe);
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 + 0x34);
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 
329 err_disable_device:
330 	sun4i_csi_capture_stop(csi);
331 
332 err_disable_pipeline:
333 	media_pipeline_stop(&csi->vdev.entity);
334 
335 err_free_scratch_buffer:
336 	dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
337 			  csi->scratch.paddr);
338 
339 err_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 
347 static 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 	media_pipeline_stop(&csi->vdev.entity);
363 
364 	dma_free_coherent(csi->dev, csi->scratch.size, csi->scratch.vaddr,
365 			  csi->scratch.paddr);
366 }
367 
368 static 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 	.wait_prepare		= vb2_ops_wait_prepare,
375 	.wait_finish		= vb2_ops_wait_finish,
376 };
377 
378 static irqreturn_t sun4i_csi_irq(int irq, void *data)
379 {
380 	struct sun4i_csi *csi = data;
381 	u32 reg;
382 
383 	reg = readl(csi->regs + CSI_INT_STA_REG);
384 
385 	/* Acknowledge the interrupts */
386 	writel(reg, csi->regs + CSI_INT_STA_REG);
387 
388 	if (!(reg & CSI_INT_FRM_DONE))
389 		return IRQ_HANDLED;
390 
391 	spin_lock(&csi->qlock);
392 	if (sun4i_csi_buffer_flip(csi, csi->sequence++)) {
393 		dev_warn(csi->dev, "%s: Flip failed\n", __func__);
394 		sun4i_csi_capture_stop(csi);
395 	}
396 	spin_unlock(&csi->qlock);
397 
398 	return IRQ_HANDLED;
399 }
400 
401 int sun4i_csi_dma_register(struct sun4i_csi *csi, int irq)
402 {
403 	struct vb2_queue *q = &csi->queue;
404 	int ret;
405 	int i;
406 
407 	spin_lock_init(&csi->qlock);
408 	mutex_init(&csi->lock);
409 
410 	INIT_LIST_HEAD(&csi->buf_list);
411 	for (i = 0; i < CSI_MAX_BUFFER; i++)
412 		csi->current_buf[i] = NULL;
413 
414 	q->min_buffers_needed = 3;
415 	q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
416 	q->io_modes = VB2_MMAP | VB2_DMABUF;
417 	q->lock = &csi->lock;
418 	q->drv_priv = csi;
419 	q->buf_struct_size = sizeof(struct sun4i_csi_buffer);
420 	q->ops = &sun4i_csi_qops;
421 	q->mem_ops = &vb2_dma_contig_memops;
422 	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
423 	q->dev = csi->dev;
424 
425 	ret = vb2_queue_init(q);
426 	if (ret < 0) {
427 		dev_err(csi->dev, "failed to initialize VB2 queue\n");
428 		goto err_free_mutex;
429 	}
430 
431 	ret = v4l2_device_register(csi->dev, &csi->v4l);
432 	if (ret) {
433 		dev_err(csi->dev, "Couldn't register the v4l2 device\n");
434 		goto err_free_mutex;
435 	}
436 
437 	ret = devm_request_irq(csi->dev, irq, sun4i_csi_irq, 0,
438 			       dev_name(csi->dev), csi);
439 	if (ret) {
440 		dev_err(csi->dev, "Couldn't register our interrupt\n");
441 		goto err_unregister_device;
442 	}
443 
444 	return 0;
445 
446 err_unregister_device:
447 	v4l2_device_unregister(&csi->v4l);
448 
449 err_free_mutex:
450 	mutex_destroy(&csi->lock);
451 	return ret;
452 }
453 
454 void sun4i_csi_dma_unregister(struct sun4i_csi *csi)
455 {
456 	v4l2_device_unregister(&csi->v4l);
457 	mutex_destroy(&csi->lock);
458 }
459