drivers/media/platform/vsp1/vsp1_uds.c

   1 /*
   2  * vsp1_uds.c  --  R-Car VSP1 Up and Down Scaler
   3  *
   4  * Copyright (C) 2013 Renesas 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 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
  38 static 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
  48 /*
  49  * uds_output_size - Return the output size for an input size and scaling ratio
  50  * @input: input size in pixels
  51  * @ratio: scaling ratio in U4.12 fixed-point format
  52  */
  53 static unsigned int uds_output_size(unsigned int input, unsigned int ratio)
  54 {
  55         if (ratio > 4096) {
  56                 /* Down-scaling */
  57                 unsigned int mp;
  58
  59                 mp = ratio / 4096;
  60                 mp = mp < 4 ? 1 : (mp < 8 ? 2 : 4);
  61
  62                 return (input - 1) / mp * mp * 4096 / ratio + 1;
  63         } else {
  64                 /* Up-scaling */
  65                 return (input - 1) * 4096 / ratio + 1;
  66         }
  67 }
  68
  69 /*
  70  * uds_output_limits - Return the min and max output sizes for an input size
  71  * @input: input size in pixels
  72  * @minimum: minimum output size (returned)
  73  * @maximum: maximum output size (returned)
  74  */
  75 static void uds_output_limits(unsigned int input,
  76                               unsigned int *minimum, unsigned int *maximum)
  77 {
  78         *minimum = max(uds_output_size(input, UDS_MAX_FACTOR), UDS_MIN_SIZE);
  79         *maximum = min(uds_output_size(input, UDS_MIN_FACTOR), UDS_MAX_SIZE);
  80 }
  81
  82 /*
  83  * uds_passband_width - Return the passband filter width for a scaling ratio
  84  * @ratio: scaling ratio in U4.12 fixed-point format
  85  */
  86 static unsigned int uds_passband_width(unsigned int ratio)
  87 {
  88         if (ratio >= 4096) {
  89                 /* Down-scaling */
  90                 unsigned int mp;
  91
  92                 mp = ratio / 4096;
  93                 mp = mp < 4 ? 1 : (mp < 8 ? 2 : 4);
  94
  95                 return 64 * 4096 * mp / ratio;
  96         } else {
  97                 /* Up-scaling */
  98                 return 64;
  99         }
 100 }
 101
 102 static unsigned int uds_compute_ratio(unsigned int input, unsigned int output)
 103 {
 104         /* TODO: This is an approximation that will need to be refined. */
 105         return (input - 1) * 4096 / (output - 1);
 106 }
 107
 108 static void uds_compute_ratios(struct vsp1_uds *uds)
 109 {
 110         struct v4l2_mbus_framefmt *input = &uds->entity.formats[UDS_PAD_SINK];
 111         struct v4l2_mbus_framefmt *output =
 112                 &uds->entity.formats[UDS_PAD_SOURCE];
 113
 114         uds->hscale = uds_compute_ratio(input->width, output->width);
 115         uds->vscale = uds_compute_ratio(input->height, output->height);
 116
 117         dev_dbg(uds->entity.vsp1->dev, "hscale %u vscale %u\n",
 118                 uds->hscale, uds->vscale);
 119 }
 120
 121 /* -----------------------------------------------------------------------------
 122  * V4L2 Subdevice Core Operations
 123  */
 124
 125 static int uds_s_stream(struct v4l2_subdev *subdev, int enable)
 126 {
 127         const struct v4l2_mbus_framefmt *format;
 128         struct vsp1_uds *uds = to_uds(subdev);
 129
 130         if (!enable)
 131                 return 0;
 132
 133         /* Enable multi-tap scaling. */
 134         vsp1_uds_write(uds, VI6_UDS_CTRL, VI6_UDS_CTRL_BC);
 135
 136         vsp1_uds_write(uds, VI6_UDS_PASS_BWIDTH,
 137                        (uds_passband_width(uds->hscale)
 138                                 << VI6_UDS_PASS_BWIDTH_H_SHIFT) |
 139                        (uds_passband_width(uds->vscale)
 140                                 << VI6_UDS_PASS_BWIDTH_V_SHIFT));
 141
 142
 143         /* Set the scaling ratios and the output size. */
 144         format = &uds->entity.formats[UDS_PAD_SOURCE];
 145
 146         vsp1_uds_write(uds, VI6_UDS_SCALE,
 147                        (uds->hscale << VI6_UDS_SCALE_HFRAC_SHIFT) |
 148                        (uds->vscale << VI6_UDS_SCALE_VFRAC_SHIFT));
 149         vsp1_uds_write(uds, VI6_UDS_CLIP_SIZE,
 150                        (format->width << VI6_UDS_CLIP_SIZE_HSIZE_SHIFT) |
 151                        (format->height << VI6_UDS_CLIP_SIZE_VSIZE_SHIFT));
 152
 153         return 0;
 154 }
 155
 156 /* -----------------------------------------------------------------------------
 157  * V4L2 Subdevice Pad Operations
 158  */
 159
 160 static int uds_enum_mbus_code(struct v4l2_subdev *subdev,
 161                               struct v4l2_subdev_fh *fh,
 162                               struct v4l2_subdev_mbus_code_enum *code)
 163 {
 164         static const unsigned int codes[] = {
 165                 V4L2_MBUS_FMT_ARGB8888_1X32,
 166                 V4L2_MBUS_FMT_AYUV8_1X32,
 167         };
 168
 169         if (code->pad == UDS_PAD_SINK) {
 170                 if (code->index >= ARRAY_SIZE(codes))
 171                         return -EINVAL;
 172
 173                 code->code = codes[code->index];
 174         } else {
 175                 struct v4l2_mbus_framefmt *format;
 176
 177                 /* The UDS can't perform format conversion, the sink format is
 178                  * always identical to the source format.
 179                  */
 180                 if (code->index)
 181                         return -EINVAL;
 182
 183                 format = v4l2_subdev_get_try_format(fh, UDS_PAD_SINK);
 184                 code->code = format->code;
 185         }
 186
 187         return 0;
 188 }
 189
 190 static int uds_enum_frame_size(struct v4l2_subdev *subdev,
 191                                struct v4l2_subdev_fh *fh,
 192                                struct v4l2_subdev_frame_size_enum *fse)
 193 {
 194         struct v4l2_mbus_framefmt *format;
 195
 196         format = v4l2_subdev_get_try_format(fh, UDS_PAD_SINK);
 197
 198         if (fse->index || fse->code != format->code)
 199                 return -EINVAL;
 200
 201         if (fse->pad == UDS_PAD_SINK) {
 202                 fse->min_width = UDS_MIN_SIZE;
 203                 fse->max_width = UDS_MAX_SIZE;
 204                 fse->min_height = UDS_MIN_SIZE;
 205                 fse->max_height = UDS_MAX_SIZE;
 206         } else {
 207                 uds_output_limits(format->width, &fse->min_width,
 208                                   &fse->max_width);
 209                 uds_output_limits(format->height, &fse->min_height,
 210                                   &fse->max_height);
 211         }
 212
 213         return 0;
 214 }
 215
 216 static int uds_get_format(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh,
 217                           struct v4l2_subdev_format *fmt)
 218 {
 219         struct vsp1_uds *uds = to_uds(subdev);
 220
 221         fmt->format = *vsp1_entity_get_pad_format(&uds->entity, fh, fmt->pad,
 222                                                   fmt->which);
 223
 224         return 0;
 225 }
 226
 227 static void uds_try_format(struct vsp1_uds *uds, struct v4l2_subdev_fh *fh,
 228                            unsigned int pad, struct v4l2_mbus_framefmt *fmt,
 229                            enum v4l2_subdev_format_whence which)
 230 {
 231         struct v4l2_mbus_framefmt *format;
 232         unsigned int minimum;
 233         unsigned int maximum;
 234
 235         switch (pad) {
 236         case UDS_PAD_SINK:
 237                 /* Default to YUV if the requested format is not supported. */
 238                 if (fmt->code != V4L2_MBUS_FMT_ARGB8888_1X32 &&
 239                     fmt->code != V4L2_MBUS_FMT_AYUV8_1X32)
 240                         fmt->code = V4L2_MBUS_FMT_AYUV8_1X32;
 241
 242                 fmt->width = clamp(fmt->width, UDS_MIN_SIZE, UDS_MAX_SIZE);
 243                 fmt->height = clamp(fmt->height, UDS_MIN_SIZE, UDS_MAX_SIZE);
 244                 break;
 245
 246         case UDS_PAD_SOURCE:
 247                 /* The UDS scales but can't perform format conversion. */
 248                 format = vsp1_entity_get_pad_format(&uds->entity, fh,
 249                                                     UDS_PAD_SINK, which);
 250                 fmt->code = format->code;
 251
 252                 uds_output_limits(format->width, &minimum, &maximum);
 253                 fmt->width = clamp(fmt->width, minimum, maximum);
 254                 uds_output_limits(format->height, &minimum, &maximum);
 255                 fmt->height = clamp(fmt->height, minimum, maximum);
 256                 break;
 257         }
 258
 259         fmt->field = V4L2_FIELD_NONE;
 260         fmt->colorspace = V4L2_COLORSPACE_SRGB;
 261 }
 262
 263 static int uds_set_format(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh,
 264                           struct v4l2_subdev_format *fmt)
 265 {
 266         struct vsp1_uds *uds = to_uds(subdev);
 267         struct v4l2_mbus_framefmt *format;
 268
 269         uds_try_format(uds, fh, fmt->pad, &fmt->format, fmt->which);
 270
 271         format = vsp1_entity_get_pad_format(&uds->entity, fh, fmt->pad,
 272                                             fmt->which);
 273         *format = fmt->format;
 274
 275         if (fmt->pad == UDS_PAD_SINK) {
 276                 /* Propagate the format to the source pad. */
 277                 format = vsp1_entity_get_pad_format(&uds->entity, fh,
 278                                                     UDS_PAD_SOURCE, fmt->which);
 279                 *format = fmt->format;
 280
 281                 uds_try_format(uds, fh, UDS_PAD_SOURCE, format, fmt->which);
 282         }
 283
 284         if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
 285                 uds_compute_ratios(uds);
 286
 287         return 0;
 288 }
 289
 290 /* -----------------------------------------------------------------------------
 291  * V4L2 Subdevice Operations
 292  */
 293
 294 static struct v4l2_subdev_video_ops uds_video_ops = {
 295         .s_stream = uds_s_stream,
 296 };
 297
 298 static struct v4l2_subdev_pad_ops uds_pad_ops = {
 299         .enum_mbus_code = uds_enum_mbus_code,
 300         .enum_frame_size = uds_enum_frame_size,
 301         .get_fmt = uds_get_format,
 302         .set_fmt = uds_set_format,
 303 };
 304
 305 static struct v4l2_subdev_ops uds_ops = {
 306         .video  = &uds_video_ops,
 307         .pad    = &uds_pad_ops,
 308 };
 309
 310 /* -----------------------------------------------------------------------------
 311  * Initialization and Cleanup
 312  */
 313
 314 struct vsp1_uds *vsp1_uds_create(struct vsp1_device *vsp1, unsigned int index)
 315 {
 316         struct v4l2_subdev *subdev;
 317         struct vsp1_uds *uds;
 318         int ret;
 319
 320         uds = devm_kzalloc(vsp1->dev, sizeof(*uds), GFP_KERNEL);
 321         if (uds == NULL)
 322                 return ERR_PTR(-ENOMEM);
 323
 324         uds->entity.type = VSP1_ENTITY_UDS;
 325         uds->entity.index = index;
 326         uds->entity.id = VI6_DPR_NODE_UDS(index);
 327
 328         ret = vsp1_entity_init(vsp1, &uds->entity, 2);
 329         if (ret < 0)
 330                 return ERR_PTR(ret);
 331
 332         /* Initialize the V4L2 subdev. */
 333         subdev = &uds->entity.subdev;
 334         v4l2_subdev_init(subdev, &uds_ops);
 335
 336         subdev->entity.ops = &vsp1_media_ops;
 337         subdev->internal_ops = &vsp1_subdev_internal_ops;
 338         snprintf(subdev->name, sizeof(subdev->name), "%s uds.%u",
 339                  dev_name(vsp1->dev), index);
 340         v4l2_set_subdevdata(subdev, uds);
 341         subdev->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 342
 343         vsp1_entity_init_formats(subdev, NULL);
 344
 345         return uds;
 346 }