linux/drivers/media/platform/vsp1/vsp1_uds.c
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   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_fh *fh,
 173                              struct v4l2_subdev_mbus_code_enum *code)
 174{
 175        static const unsigned int codes[] = {
 176                V4L2_MBUS_FMT_ARGB8888_1X32,
 177                V4L2_MBUS_FMT_AYUV8_1X32,
 178        };
 179
 180        if (code->pad == UDS_PAD_SINK) {
 181                if (code->index >= ARRAY_SIZE(codes))
 182                        return -EINVAL;
 183
 184                code->code = codes[code->index];
 185        } else {
 186                struct v4l2_mbus_framefmt *format;
 187
 188                /* The UDS can't perform format conversion, the sink format is
 189                 * always identical to the source format.
 190                 */
 191                if (code->index)
 192                        return -EINVAL;
 193
 194                format = v4l2_subdev_get_try_format(fh, UDS_PAD_SINK);
 195                code->code = format->code;
 196        }
 197
 198        return 0;
 199}
 200
 201static int uds_enum_frame_size(struct v4l2_subdev *subdev,
 202                               struct v4l2_subdev_fh *fh,
 203                               struct v4l2_subdev_frame_size_enum *fse)
 204{
 205        struct v4l2_mbus_framefmt *format;
 206
 207        format = v4l2_subdev_get_try_format(fh, UDS_PAD_SINK);
 208
 209        if (fse->index || fse->code != format->code)
 210                return -EINVAL;
 211
 212        if (fse->pad == UDS_PAD_SINK) {
 213                fse->min_width = UDS_MIN_SIZE;
 214                fse->max_width = UDS_MAX_SIZE;
 215                fse->min_height = UDS_MIN_SIZE;
 216                fse->max_height = UDS_MAX_SIZE;
 217        } else {
 218                uds_output_limits(format->width, &fse->min_width,
 219                                  &fse->max_width);
 220                uds_output_limits(format->height, &fse->min_height,
 221                                  &fse->max_height);
 222        }
 223
 224        return 0;
 225}
 226
 227static int uds_get_format(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh,
 228                          struct v4l2_subdev_format *fmt)
 229{
 230        struct vsp1_uds *uds = to_uds(subdev);
 231
 232        fmt->format = *vsp1_entity_get_pad_format(&uds->entity, fh, fmt->pad,
 233                                                  fmt->which);
 234
 235        return 0;
 236}
 237
 238static void uds_try_format(struct vsp1_uds *uds, struct v4l2_subdev_fh *fh,
 239                           unsigned int pad, struct v4l2_mbus_framefmt *fmt,
 240                           enum v4l2_subdev_format_whence which)
 241{
 242        struct v4l2_mbus_framefmt *format;
 243        unsigned int minimum;
 244        unsigned int maximum;
 245
 246        switch (pad) {
 247        case UDS_PAD_SINK:
 248                /* Default to YUV if the requested format is not supported. */
 249                if (fmt->code != V4L2_MBUS_FMT_ARGB8888_1X32 &&
 250                    fmt->code != V4L2_MBUS_FMT_AYUV8_1X32)
 251                        fmt->code = V4L2_MBUS_FMT_AYUV8_1X32;
 252
 253                fmt->width = clamp(fmt->width, UDS_MIN_SIZE, UDS_MAX_SIZE);
 254                fmt->height = clamp(fmt->height, UDS_MIN_SIZE, UDS_MAX_SIZE);
 255                break;
 256
 257        case UDS_PAD_SOURCE:
 258                /* The UDS scales but can't perform format conversion. */
 259                format = vsp1_entity_get_pad_format(&uds->entity, fh,
 260                                                    UDS_PAD_SINK, which);
 261                fmt->code = format->code;
 262
 263                uds_output_limits(format->width, &minimum, &maximum);
 264                fmt->width = clamp(fmt->width, minimum, maximum);
 265                uds_output_limits(format->height, &minimum, &maximum);
 266                fmt->height = clamp(fmt->height, minimum, maximum);
 267                break;
 268        }
 269
 270        fmt->field = V4L2_FIELD_NONE;
 271        fmt->colorspace = V4L2_COLORSPACE_SRGB;
 272}
 273
 274static int uds_set_format(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh,
 275                          struct v4l2_subdev_format *fmt)
 276{
 277        struct vsp1_uds *uds = to_uds(subdev);
 278        struct v4l2_mbus_framefmt *format;
 279
 280        uds_try_format(uds, fh, fmt->pad, &fmt->format, fmt->which);
 281
 282        format = vsp1_entity_get_pad_format(&uds->entity, fh, fmt->pad,
 283                                            fmt->which);
 284        *format = fmt->format;
 285
 286        if (fmt->pad == UDS_PAD_SINK) {
 287                /* Propagate the format to the source pad. */
 288                format = vsp1_entity_get_pad_format(&uds->entity, fh,
 289                                                    UDS_PAD_SOURCE, fmt->which);
 290                *format = fmt->format;
 291
 292                uds_try_format(uds, fh, UDS_PAD_SOURCE, format, fmt->which);
 293        }
 294
 295        return 0;
 296}
 297
 298/* -----------------------------------------------------------------------------
 299 * V4L2 Subdevice Operations
 300 */
 301
 302static struct v4l2_subdev_video_ops uds_video_ops = {
 303        .s_stream = uds_s_stream,
 304};
 305
 306static struct v4l2_subdev_pad_ops uds_pad_ops = {
 307        .enum_mbus_code = uds_enum_mbus_code,
 308        .enum_frame_size = uds_enum_frame_size,
 309        .get_fmt = uds_get_format,
 310        .set_fmt = uds_set_format,
 311};
 312
 313static struct v4l2_subdev_ops uds_ops = {
 314        .video  = &uds_video_ops,
 315        .pad    = &uds_pad_ops,
 316};
 317
 318/* -----------------------------------------------------------------------------
 319 * Initialization and Cleanup
 320 */
 321
 322struct vsp1_uds *vsp1_uds_create(struct vsp1_device *vsp1, unsigned int index)
 323{
 324        struct v4l2_subdev *subdev;
 325        struct vsp1_uds *uds;
 326        int ret;
 327
 328        uds = devm_kzalloc(vsp1->dev, sizeof(*uds), GFP_KERNEL);
 329        if (uds == NULL)
 330                return ERR_PTR(-ENOMEM);
 331
 332        uds->entity.type = VSP1_ENTITY_UDS;
 333        uds->entity.index = index;
 334
 335        ret = vsp1_entity_init(vsp1, &uds->entity, 2);
 336        if (ret < 0)
 337                return ERR_PTR(ret);
 338
 339        /* Initialize the V4L2 subdev. */
 340        subdev = &uds->entity.subdev;
 341        v4l2_subdev_init(subdev, &uds_ops);
 342
 343        subdev->entity.ops = &vsp1_media_ops;
 344        subdev->internal_ops = &vsp1_subdev_internal_ops;
 345        snprintf(subdev->name, sizeof(subdev->name), "%s uds.%u",
 346                 dev_name(vsp1->dev), index);
 347        v4l2_set_subdevdata(subdev, uds);
 348        subdev->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 349
 350        vsp1_entity_init_formats(subdev, NULL);
 351
 352        return uds;
 353}
 354