drivers/media/platform/vsp1/vsp1_uds.c

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