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 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 void 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  */
  58 static 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  */
  80 static 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  */
  91 static 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
 107 static 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
 117 static 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
 171 static 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
 201 static 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
 227 static 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
 238 static 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
 274 static 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
 302 static struct v4l2_subdev_video_ops uds_video_ops = {
 303         .s_stream = uds_s_stream,
 304 };
 305
 306 static 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
 313 static 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
 322 struct 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 }