1/*
2 * vsp1_uds.c  --  R-Car VSP1 Up and Down Scaler
3 *
4 * Copyright (C) 2013-2014 Renesas Electronics Corporation
5 *
6 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14#include <linux/device.h>
15#include <linux/gfp.h>
16
17#include <media/v4l2-subdev.h>
18
19#include "vsp1.h"
20#include "vsp1_uds.h"
21
22#define UDS_MIN_SIZE				4U
23#define UDS_MAX_SIZE				8190U
24
25#define UDS_MIN_FACTOR				0x0100
26#define UDS_MAX_FACTOR				0xffff
27
28/* -----------------------------------------------------------------------------
29 * Device Access
30 */
31
32static inline u32 vsp1_uds_read(struct vsp1_uds *uds, u32 reg)
33{
34	return vsp1_read(uds->entity.vsp1,
35			 reg + uds->entity.index * VI6_UDS_OFFSET);
36}
37
38static inline void vsp1_uds_write(struct vsp1_uds *uds, u32 reg, u32 data)
39{
40	vsp1_write(uds->entity.vsp1,
41		   reg + uds->entity.index * VI6_UDS_OFFSET, data);
42}
43
44/* -----------------------------------------------------------------------------
45 * Scaling Computation
46 */
47
48void vsp1_uds_set_alpha(struct vsp1_uds *uds, unsigned int alpha)
49{
50	vsp1_uds_write(uds, VI6_UDS_ALPVAL, alpha << VI6_UDS_ALPVAL_VAL0_SHIFT);
51}
52
53/*
54 * uds_output_size - Return the output size for an input size and scaling ratio
55 * @input: input size in pixels
56 * @ratio: scaling ratio in U4.12 fixed-point format
57 */
58static unsigned int uds_output_size(unsigned int input, unsigned int ratio)
59{
60	if (ratio > 4096) {
61		/* Down-scaling */
62		unsigned int mp;
63
64		mp = ratio / 4096;
65		mp = mp < 4 ? 1 : (mp < 8 ? 2 : 4);
66
67		return (input - 1) / mp * mp * 4096 / ratio + 1;
68	} else {
69		/* Up-scaling */
70		return (input - 1) * 4096 / ratio + 1;
71	}
72}
73
74/*
75 * uds_output_limits - Return the min and max output sizes for an input size
76 * @input: input size in pixels
77 * @minimum: minimum output size (returned)
78 * @maximum: maximum output size (returned)
79 */
80static void uds_output_limits(unsigned int input,
81			      unsigned int *minimum, unsigned int *maximum)
82{
83	*minimum = max(uds_output_size(input, UDS_MAX_FACTOR), UDS_MIN_SIZE);
84	*maximum = min(uds_output_size(input, UDS_MIN_FACTOR), UDS_MAX_SIZE);
85}
86
87/*
88 * uds_passband_width - Return the passband filter width for a scaling ratio
89 * @ratio: scaling ratio in U4.12 fixed-point format
90 */
91static unsigned int uds_passband_width(unsigned int ratio)
92{
93	if (ratio >= 4096) {
94		/* Down-scaling */
95		unsigned int mp;
96
97		mp = ratio / 4096;
98		mp = mp < 4 ? 1 : (mp < 8 ? 2 : 4);
99
100		return 64 * 4096 * mp / ratio;
101	} else {
102		/* Up-scaling */
103		return 64;
104	}
105}
106
107static unsigned int uds_compute_ratio(unsigned int input, unsigned int output)
108{
109	/* TODO: This is an approximation that will need to be refined. */
110	return (input - 1) * 4096 / (output - 1);
111}
112
113/* -----------------------------------------------------------------------------
114 * V4L2 Subdevice Core Operations
115 */
116
117static int uds_s_stream(struct v4l2_subdev *subdev, int enable)
118{
119	struct vsp1_uds *uds = to_uds(subdev);
120	const struct v4l2_mbus_framefmt *output;
121	const struct v4l2_mbus_framefmt *input;
122	unsigned int hscale;
123	unsigned int vscale;
124	bool multitap;
125
126	if (!enable)
127		return 0;
128
129	input = &uds->entity.formats[UDS_PAD_SINK];
130	output = &uds->entity.formats[UDS_PAD_SOURCE];
131
132	hscale = uds_compute_ratio(input->width, output->width);
133	vscale = uds_compute_ratio(input->height, output->height);
134
135	dev_dbg(uds->entity.vsp1->dev, "hscale %u vscale %u\n", hscale, vscale);
136
137	/* Multi-tap scaling can't be enabled along with alpha scaling when
138	 * scaling down with a factor lower than or equal to 1/2 in either
139	 * direction.
140	 */
141	if (uds->scale_alpha && (hscale >= 8192 || vscale >= 8192))
142		multitap = false;
143	else
144		multitap = true;
145
146	vsp1_uds_write(uds, VI6_UDS_CTRL,
147		       (uds->scale_alpha ? VI6_UDS_CTRL_AON : 0) |
148		       (multitap ? VI6_UDS_CTRL_BC : 0));
149
150	vsp1_uds_write(uds, VI6_UDS_PASS_BWIDTH,
151		       (uds_passband_width(hscale)
152				<< VI6_UDS_PASS_BWIDTH_H_SHIFT) |
153		       (uds_passband_width(vscale)
154				<< VI6_UDS_PASS_BWIDTH_V_SHIFT));
155
156	/* Set the scaling ratios and the output size. */
157	vsp1_uds_write(uds, VI6_UDS_SCALE,
158		       (hscale << VI6_UDS_SCALE_HFRAC_SHIFT) |
159		       (vscale << VI6_UDS_SCALE_VFRAC_SHIFT));
160	vsp1_uds_write(uds, VI6_UDS_CLIP_SIZE,
161		       (output->width << VI6_UDS_CLIP_SIZE_HSIZE_SHIFT) |
162		       (output->height << VI6_UDS_CLIP_SIZE_VSIZE_SHIFT));
163
164	return 0;
165}
166
167/* -----------------------------------------------------------------------------
168 * V4L2 Subdevice Pad Operations
169 */
170
171static int uds_enum_mbus_code(struct v4l2_subdev *subdev,
172			      struct v4l2_subdev_pad_config *cfg,
173			      struct v4l2_subdev_mbus_code_enum *code)
174{
175	static const unsigned int codes[] = {
176		MEDIA_BUS_FMT_ARGB8888_1X32,
177		MEDIA_BUS_FMT_AYUV8_1X32,
178	};
179	struct vsp1_uds *uds = to_uds(subdev);
180
181	if (code->pad == UDS_PAD_SINK) {
182		if (code->index >= ARRAY_SIZE(codes))
183			return -EINVAL;
184
185		code->code = codes[code->index];
186	} else {
187		struct v4l2_mbus_framefmt *format;
188
189		/* The UDS can't perform format conversion, the sink format is
190		 * always identical to the source format.
191		 */
192		if (code->index)
193			return -EINVAL;
194
195		format = vsp1_entity_get_pad_format(&uds->entity, cfg,
196						    UDS_PAD_SINK, code->which);
197		code->code = format->code;
198	}
199
200	return 0;
201}
202
203static int uds_enum_frame_size(struct v4l2_subdev *subdev,
204			       struct v4l2_subdev_pad_config *cfg,
205			       struct v4l2_subdev_frame_size_enum *fse)
206{
207	struct vsp1_uds *uds = to_uds(subdev);
208	struct v4l2_mbus_framefmt *format;
209
210	format = vsp1_entity_get_pad_format(&uds->entity, cfg,
211					    UDS_PAD_SINK, fse->which);
212
213	if (fse->index || fse->code != format->code)
214		return -EINVAL;
215
216	if (fse->pad == UDS_PAD_SINK) {
217		fse->min_width = UDS_MIN_SIZE;
218		fse->max_width = UDS_MAX_SIZE;
219		fse->min_height = UDS_MIN_SIZE;
220		fse->max_height = UDS_MAX_SIZE;
221	} else {
222		uds_output_limits(format->width, &fse->min_width,
223				  &fse->max_width);
224		uds_output_limits(format->height, &fse->min_height,
225				  &fse->max_height);
226	}
227
228	return 0;
229}
230
231static int uds_get_format(struct v4l2_subdev *subdev, struct v4l2_subdev_pad_config *cfg,
232			  struct v4l2_subdev_format *fmt)
233{
234	struct vsp1_uds *uds = to_uds(subdev);
235
236	fmt->format = *vsp1_entity_get_pad_format(&uds->entity, cfg, fmt->pad,
237						  fmt->which);
238
239	return 0;
240}
241
242static void uds_try_format(struct vsp1_uds *uds, struct v4l2_subdev_pad_config *cfg,
243			   unsigned int pad, struct v4l2_mbus_framefmt *fmt,
244			   enum v4l2_subdev_format_whence which)
245{
246	struct v4l2_mbus_framefmt *format;
247	unsigned int minimum;
248	unsigned int maximum;
249
250	switch (pad) {
251	case UDS_PAD_SINK:
252		/* Default to YUV if the requested format is not supported. */
253		if (fmt->code != MEDIA_BUS_FMT_ARGB8888_1X32 &&
254		    fmt->code != MEDIA_BUS_FMT_AYUV8_1X32)
255			fmt->code = MEDIA_BUS_FMT_AYUV8_1X32;
256
257		fmt->width = clamp(fmt->width, UDS_MIN_SIZE, UDS_MAX_SIZE);
258		fmt->height = clamp(fmt->height, UDS_MIN_SIZE, UDS_MAX_SIZE);
259		break;
260
261	case UDS_PAD_SOURCE:
262		/* The UDS scales but can't perform format conversion. */
263		format = vsp1_entity_get_pad_format(&uds->entity, cfg,
264						    UDS_PAD_SINK, which);
265		fmt->code = format->code;
266
267		uds_output_limits(format->width, &minimum, &maximum);
268		fmt->width = clamp(fmt->width, minimum, maximum);
269		uds_output_limits(format->height, &minimum, &maximum);
270		fmt->height = clamp(fmt->height, minimum, maximum);
271		break;
272	}
273
274	fmt->field = V4L2_FIELD_NONE;
275	fmt->colorspace = V4L2_COLORSPACE_SRGB;
276}
277
278static int uds_set_format(struct v4l2_subdev *subdev, struct v4l2_subdev_pad_config *cfg,
279			  struct v4l2_subdev_format *fmt)
280{
281	struct vsp1_uds *uds = to_uds(subdev);
282	struct v4l2_mbus_framefmt *format;
283
284	uds_try_format(uds, cfg, fmt->pad, &fmt->format, fmt->which);
285
286	format = vsp1_entity_get_pad_format(&uds->entity, cfg, fmt->pad,
287					    fmt->which);
288	*format = fmt->format;
289
290	if (fmt->pad == UDS_PAD_SINK) {
291		/* Propagate the format to the source pad. */
292		format = vsp1_entity_get_pad_format(&uds->entity, cfg,
293						    UDS_PAD_SOURCE, fmt->which);
294		*format = fmt->format;
295
296		uds_try_format(uds, cfg, UDS_PAD_SOURCE, format, fmt->which);
297	}
298
299	return 0;
300}
301
302/* -----------------------------------------------------------------------------
303 * V4L2 Subdevice Operations
304 */
305
306static struct v4l2_subdev_video_ops uds_video_ops = {
307	.s_stream = uds_s_stream,
308};
309
310static struct v4l2_subdev_pad_ops uds_pad_ops = {
311	.enum_mbus_code = uds_enum_mbus_code,
312	.enum_frame_size = uds_enum_frame_size,
313	.get_fmt = uds_get_format,
314	.set_fmt = uds_set_format,
315};
316
317static struct v4l2_subdev_ops uds_ops = {
318	.video	= &uds_video_ops,
319	.pad    = &uds_pad_ops,
320};
321
322/* -----------------------------------------------------------------------------
323 * Initialization and Cleanup
324 */
325
326struct vsp1_uds *vsp1_uds_create(struct vsp1_device *vsp1, unsigned int index)
327{
328	struct v4l2_subdev *subdev;
329	struct vsp1_uds *uds;
330	int ret;
331
332	uds = devm_kzalloc(vsp1->dev, sizeof(*uds), GFP_KERNEL);
333	if (uds == NULL)
334		return ERR_PTR(-ENOMEM);
335
336	uds->entity.type = VSP1_ENTITY_UDS;
337	uds->entity.index = index;
338
339	ret = vsp1_entity_init(vsp1, &uds->entity, 2);
340	if (ret < 0)
341		return ERR_PTR(ret);
342
343	/* Initialize the V4L2 subdev. */
344	subdev = &uds->entity.subdev;
345	v4l2_subdev_init(subdev, &uds_ops);
346
347	subdev->entity.ops = &vsp1_media_ops;
348	subdev->internal_ops = &vsp1_subdev_internal_ops;
349	snprintf(subdev->name, sizeof(subdev->name), "%s uds.%u",
350		 dev_name(vsp1->dev), index);
351	v4l2_set_subdevdata(subdev, uds);
352	subdev->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
353
354	vsp1_entity_init_formats(subdev, NULL);
355
356	return uds;
357}
358