drivers/gpu/drm/arm/hdlcd_crtc.c

   1 /*
   2  * Copyright (C) 2013-2015 ARM Limited
   3  * Author: Liviu Dudau <Liviu.Dudau@arm.com>
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License.  See the file COPYING in the main directory of this archive
   7  * for more details.
   8  *
   9  *  Implementation of a CRTC class for the HDLCD driver.
  10  */
  11
  12 #include <linux/clk.h>
  13 #include <linux/of_graph.h>
  14 #include <linux/platform_data/simplefb.h>
  15
  16 #include <video/videomode.h>
  17
  18 #include <drm/drm_atomic.h>
  19 #include <drm/drm_atomic_helper.h>
  20 #include <drm/drm_crtc.h>
  21 #include <drm/drm_fb_cma_helper.h>
  22 #include <drm/drm_fb_helper.h>
  23 #include <drm/drm_gem_cma_helper.h>
  24 #include <drm/drm_of.h>
  25 #include <drm/drm_plane_helper.h>
  26 #include <drm/drm_probe_helper.h>
  27 #include <drm/drm_vblank.h>
  28
  29 #include "hdlcd_drv.h"
  30 #include "hdlcd_regs.h"
  31
  32 /*
  33  * The HDLCD controller is a dumb RGB streamer that gets connected to
  34  * a single HDMI transmitter or in the case of the ARM Models it gets
  35  * emulated by the software that does the actual rendering.
  36  *
  37  */
  38
  39 static void hdlcd_crtc_cleanup(struct drm_crtc *crtc)
  40 {
  41         struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
  42
  43         /* stop the controller on cleanup */
  44         hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
  45         drm_crtc_cleanup(crtc);
  46 }
  47
  48 static int hdlcd_crtc_enable_vblank(struct drm_crtc *crtc)
  49 {
  50         struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
  51         unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
  52
  53         hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask | HDLCD_INTERRUPT_VSYNC);
  54
  55         return 0;
  56 }
  57
  58 static void hdlcd_crtc_disable_vblank(struct drm_crtc *crtc)
  59 {
  60         struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
  61         unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
  62
  63         hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask & ~HDLCD_INTERRUPT_VSYNC);
  64 }
  65
  66 static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
  67         .destroy = hdlcd_crtc_cleanup,
  68         .set_config = drm_atomic_helper_set_config,
  69         .page_flip = drm_atomic_helper_page_flip,
  70         .reset = drm_atomic_helper_crtc_reset,
  71         .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
  72         .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
  73         .enable_vblank = hdlcd_crtc_enable_vblank,
  74         .disable_vblank = hdlcd_crtc_disable_vblank,
  75 };
  76
  77 static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
  78
  79 /*
  80  * Setup the HDLCD registers for decoding the pixels out of the framebuffer
  81  */
  82 static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
  83 {
  84         unsigned int btpp;
  85         struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
  86         const struct drm_framebuffer *fb = crtc->primary->state->fb;
  87         uint32_t pixel_format;
  88         struct simplefb_format *format = NULL;
  89         int i;
  90
  91         pixel_format = fb->format->format;
  92
  93         for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
  94                 if (supported_formats[i].fourcc == pixel_format)
  95                         format = &supported_formats[i];
  96         }
  97
  98         if (WARN_ON(!format))
  99                 return 0;
 100
 101         /* HDLCD uses 'bytes per pixel', zero means 1 byte */
 102         btpp = (format->bits_per_pixel + 7) / 8;
 103         hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
 104
 105         /*
 106          * The format of the HDLCD_REG_<color>_SELECT register is:
 107          *   - bits[23:16] - default value for that color component
 108          *   - bits[11:8]  - number of bits to extract for each color component
 109          *   - bits[4:0]   - index of the lowest bit to extract
 110          *
 111          * The default color value is used when bits[11:8] are zero, when the
 112          * pixel is outside the visible frame area or when there is a
 113          * buffer underrun.
 114          */
 115         hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
 116 #ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
 117                     0x00ff0000 |        /* show underruns in red */
 118 #endif
 119                     ((format->red.length & 0xf) << 8));
 120         hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
 121                     ((format->green.length & 0xf) << 8));
 122         hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
 123                     ((format->blue.length & 0xf) << 8));
 124
 125         return 0;
 126 }
 127
 128 static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
 129 {
 130         struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 131         struct drm_display_mode *m = &crtc->state->adjusted_mode;
 132         struct videomode vm;
 133         unsigned int polarities, err;
 134
 135         vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
 136         vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
 137         vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
 138         vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
 139         vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
 140         vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
 141
 142         polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
 143
 144         if (m->flags & DRM_MODE_FLAG_PHSYNC)
 145                 polarities |= HDLCD_POLARITY_HSYNC;
 146         if (m->flags & DRM_MODE_FLAG_PVSYNC)
 147                 polarities |= HDLCD_POLARITY_VSYNC;
 148
 149         /* Allow max number of outstanding requests and largest burst size */
 150         hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
 151                     HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
 152
 153         hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
 154         hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
 155         hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
 156         hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
 157         hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
 158         hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
 159         hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
 160         hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
 161         hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
 162
 163         err = hdlcd_set_pxl_fmt(crtc);
 164         if (err)
 165                 return;
 166
 167         clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
 168 }
 169
 170 static void hdlcd_crtc_atomic_enable(struct drm_crtc *crtc,
 171                                      struct drm_atomic_state *state)
 172 {
 173         struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 174
 175         clk_prepare_enable(hdlcd->clk);
 176         hdlcd_crtc_mode_set_nofb(crtc);
 177         hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
 178         drm_crtc_vblank_on(crtc);
 179 }
 180
 181 static void hdlcd_crtc_atomic_disable(struct drm_crtc *crtc,
 182                                       struct drm_atomic_state *state)
 183 {
 184         struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 185
 186         drm_crtc_vblank_off(crtc);
 187         hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
 188         clk_disable_unprepare(hdlcd->clk);
 189 }
 190
 191 static enum drm_mode_status hdlcd_crtc_mode_valid(struct drm_crtc *crtc,
 192                 const struct drm_display_mode *mode)
 193 {
 194         struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 195         long rate, clk_rate = mode->clock * 1000;
 196
 197         rate = clk_round_rate(hdlcd->clk, clk_rate);
 198         /* 0.1% seems a close enough tolerance for the TDA19988 on Juno */
 199         if (abs(rate - clk_rate) * 1000 > clk_rate) {
 200                 /* clock required by mode not supported by hardware */
 201                 return MODE_NOCLOCK;
 202         }
 203
 204         return MODE_OK;
 205 }
 206
 207 static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
 208                                     struct drm_atomic_state *state)
 209 {
 210         struct drm_pending_vblank_event *event = crtc->state->event;
 211
 212         if (event) {
 213                 crtc->state->event = NULL;
 214
 215                 spin_lock_irq(&crtc->dev->event_lock);
 216                 if (drm_crtc_vblank_get(crtc) == 0)
 217                         drm_crtc_arm_vblank_event(crtc, event);
 218                 else
 219                         drm_crtc_send_vblank_event(crtc, event);
 220                 spin_unlock_irq(&crtc->dev->event_lock);
 221         }
 222 }
 223
 224 static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
 225         .mode_valid     = hdlcd_crtc_mode_valid,
 226         .atomic_begin   = hdlcd_crtc_atomic_begin,
 227         .atomic_enable  = hdlcd_crtc_atomic_enable,
 228         .atomic_disable = hdlcd_crtc_atomic_disable,
 229 };
 230
 231 static int hdlcd_plane_atomic_check(struct drm_plane *plane,
 232                                     struct drm_plane_state *state)
 233 {
 234         int i;
 235         struct drm_crtc *crtc;
 236         struct drm_crtc_state *crtc_state;
 237         u32 src_h = state->src_h >> 16;
 238
 239         /* only the HDLCD_REG_FB_LINE_COUNT register has a limit */
 240         if (src_h >= HDLCD_MAX_YRES) {
 241                 DRM_DEBUG_KMS("Invalid source width: %d\n", src_h);
 242                 return -EINVAL;
 243         }
 244
 245         for_each_new_crtc_in_state(state->state, crtc, crtc_state, i) {
 246                 /* we cannot disable the plane while the CRTC is active */
 247                 if (!state->fb && crtc_state->active)
 248                         return -EINVAL;
 249                 return drm_atomic_helper_check_plane_state(state, crtc_state,
 250                                                 DRM_PLANE_HELPER_NO_SCALING,
 251                                                 DRM_PLANE_HELPER_NO_SCALING,
 252                                                 false, true);
 253         }
 254
 255         return 0;
 256 }
 257
 258 static void hdlcd_plane_atomic_update(struct drm_plane *plane,
 259                                       struct drm_plane_state *state)
 260 {
 261         struct drm_framebuffer *fb = plane->state->fb;
 262         struct hdlcd_drm_private *hdlcd;
 263         u32 dest_h;
 264         dma_addr_t scanout_start;
 265
 266         if (!fb)
 267                 return;
 268
 269         dest_h = drm_rect_height(&plane->state->dst);
 270         scanout_start = drm_fb_cma_get_gem_addr(fb, plane->state, 0);
 271
 272         hdlcd = plane->dev->dev_private;
 273         hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, fb->pitches[0]);
 274         hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, fb->pitches[0]);
 275         hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, dest_h - 1);
 276         hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
 277 }
 278
 279 static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
 280         .atomic_check = hdlcd_plane_atomic_check,
 281         .atomic_update = hdlcd_plane_atomic_update,
 282 };
 283
 284 static const struct drm_plane_funcs hdlcd_plane_funcs = {
 285         .update_plane           = drm_atomic_helper_update_plane,
 286         .disable_plane          = drm_atomic_helper_disable_plane,
 287         .destroy                = drm_plane_cleanup,
 288         .reset                  = drm_atomic_helper_plane_reset,
 289         .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 290         .atomic_destroy_state   = drm_atomic_helper_plane_destroy_state,
 291 };
 292
 293 static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
 294 {
 295         struct hdlcd_drm_private *hdlcd = drm->dev_private;
 296         struct drm_plane *plane = NULL;
 297         u32 formats[ARRAY_SIZE(supported_formats)], i;
 298         int ret;
 299
 300         plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
 301         if (!plane)
 302                 return ERR_PTR(-ENOMEM);
 303
 304         for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
 305                 formats[i] = supported_formats[i].fourcc;
 306
 307         ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
 308                                        formats, ARRAY_SIZE(formats),
 309                                        NULL,
 310                                        DRM_PLANE_TYPE_PRIMARY, NULL);
 311         if (ret)
 312                 return ERR_PTR(ret);
 313
 314         drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
 315         hdlcd->plane = plane;
 316
 317         return plane;
 318 }
 319
 320 int hdlcd_setup_crtc(struct drm_device *drm)
 321 {
 322         struct hdlcd_drm_private *hdlcd = drm->dev_private;
 323         struct drm_plane *primary;
 324         int ret;
 325
 326         primary = hdlcd_plane_init(drm);
 327         if (IS_ERR(primary))
 328                 return PTR_ERR(primary);
 329
 330         ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
 331                                         &hdlcd_crtc_funcs, NULL);
 332         if (ret)
 333                 return ret;
 334
 335         drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
 336         return 0;
 337 }