Quelle  hdlcd_crtc.c   Sprache: C

/*
 * Copyright (C) 2013-2015 ARM Limited
 * Author: Liviu Dudau <Liviu.Dudau@arm.com>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 *
 *  Implementation of a CRTC class for the HDLCD driver.
 */

#include <linux/clk.h>
#include <linux/of_graph.h>

#include <video/pixel_format.h>
#include <video/videomode.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_of.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_vblank.h>

#include "hdlcd_drv.h"
#include "hdlcd_regs.h"

/*
 * The HDLCD controller is a dumb RGB streamer that gets connected to
 * a single HDMI transmitter or in the case of the ARM Models it gets
 * emulated by the software that does the actual rendering.
 *
 */

static void hdlcd_crtc_cleanup(struct drm_crtc *crtc)
{
 struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);

 /* stop the controller on cleanup */
 hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
 drm_crtc_cleanup(crtc);
}

static int hdlcd_crtc_enable_vblank(struct drm_crtc *crtc)
{
 struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);

 hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask | HDLCD_INTERRUPT_VSYNC);

 return 0;
}

static void hdlcd_crtc_disable_vblank(struct drm_crtc *crtc)
{
 struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);

 hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask & ~HDLCD_INTERRUPT_VSYNC);
}

static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
 .destroy = hdlcd_crtc_cleanup,
 .set_config = drm_atomic_helper_set_config,
 .page_flip = drm_atomic_helper_page_flip,
 .reset = drm_atomic_helper_crtc_reset,
 .atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
 .atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
 .enable_vblank = hdlcd_crtc_enable_vblank,
 .disable_vblank = hdlcd_crtc_disable_vblank,
};

static const struct {
 u32 fourcc;
 struct pixel_format pixel;
} supported_formats[] = {
 { DRM_FORMAT_RGB565, PIXEL_FORMAT_RGB565 },
 { DRM_FORMAT_XRGB1555, PIXEL_FORMAT_XRGB1555 },
 { DRM_FORMAT_RGB888, PIXEL_FORMAT_RGB888 },
 { DRM_FORMAT_XRGB8888, PIXEL_FORMAT_XRGB8888 },
 { DRM_FORMAT_XBGR8888, PIXEL_FORMAT_XBGR8888 },
 { DRM_FORMAT_XRGB2101010, PIXEL_FORMAT_XRGB2101010},
};

/*
 * Setup the HDLCD registers for decoding the pixels out of the framebuffer
 */
static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
{
 unsigned int btpp;
 struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 const struct drm_framebuffer *fb = crtc->primary->state->fb;
 const struct pixel_format *format = NULL;
 int i;

 for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
  if (supported_formats[i].fourcc == fb->format->format)
   format = &supported_formats[i].pixel;
 }

 if (WARN_ON(!format))
  return 0;

 /* HDLCD uses 'bytes per pixel', zero means 1 byte */
 btpp = (format->bits_per_pixel + 7) / 8;
 hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);

 /*
 * The format of the HDLCD_REG_<color>_SELECT register is:
 *   - bits[23:16] - default value for that color component
 *   - bits[11:8]  - number of bits to extract for each color component
 *   - bits[4:0]   - index of the lowest bit to extract
 *
 * The default color value is used when bits[11:8] are zero, when the
 * pixel is outside the visible frame area or when there is a
 * buffer underrun.
 */
 hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
#ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
      0x00ff0000 | /* show underruns in red */
#endif
      ((format->red.length & 0xf) << 8));
 hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
      ((format->green.length & 0xf) << 8));
 hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
      ((format->blue.length & 0xf) << 8));

 return 0;
}

static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
 struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 struct drm_display_mode *m = &crtc->state->adjusted_mode;
 struct videomode vm;
 unsigned int polarities, err;

 vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
 vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
 vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
 vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
 vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
 vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;

 polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;

 if (m->flags & DRM_MODE_FLAG_PHSYNC)
  polarities |= HDLCD_POLARITY_HSYNC;
 if (m->flags & DRM_MODE_FLAG_PVSYNC)
  polarities |= HDLCD_POLARITY_VSYNC;

 /* Allow max number of outstanding requests and largest burst size */
 hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
      HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);

 hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
 hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
 hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
 hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
 hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
 hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
 hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
 hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
 hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);

 err = hdlcd_set_pxl_fmt(crtc);
 if (err)
  return;

 clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
}

static void hdlcd_crtc_atomic_enable(struct drm_crtc *crtc,
         struct drm_atomic_state *state)
{
 struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);

 clk_prepare_enable(hdlcd->clk);
 hdlcd_crtc_mode_set_nofb(crtc);
 hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
 drm_crtc_vblank_on(crtc);
}

static void hdlcd_crtc_atomic_disable(struct drm_crtc *crtc,
          struct drm_atomic_state *state)
{
 struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);

 drm_crtc_vblank_off(crtc);
 hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
 clk_disable_unprepare(hdlcd->clk);
}

static enum drm_mode_status hdlcd_crtc_mode_valid(struct drm_crtc *crtc,
  const struct drm_display_mode *mode)
{
 struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 long rate, clk_rate = mode->clock * 1000;

 rate = clk_round_rate(hdlcd->clk, clk_rate);
 /* 0.1% seems a close enough tolerance for the TDA19988 on Juno */
 if (abs(rate - clk_rate) * 1000 > clk_rate) {
  /* clock required by mode not supported by hardware */
  return MODE_NOCLOCK;
 }

 return MODE_OK;
}

static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
        struct drm_atomic_state *state)
{
 struct drm_pending_vblank_event *event = crtc->state->event;

 if (event) {
  crtc->state->event = NULL;

  spin_lock_irq(&crtc->dev->event_lock);
  if (drm_crtc_vblank_get(crtc) == 0)
   drm_crtc_arm_vblank_event(crtc, event);
  else
   drm_crtc_send_vblank_event(crtc, event);
  spin_unlock_irq(&crtc->dev->event_lock);
 }
}

static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
 .mode_valid = hdlcd_crtc_mode_valid,
 .atomic_begin = hdlcd_crtc_atomic_begin,
 .atomic_enable = hdlcd_crtc_atomic_enable,
 .atomic_disable = hdlcd_crtc_atomic_disable,
};

static int hdlcd_plane_atomic_check(struct drm_plane *plane,
        struct drm_atomic_state *state)
{
 struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
           plane);
 int i;
 struct drm_crtc *crtc;
 struct drm_crtc_state *crtc_state;
 u32 src_h = new_plane_state->src_h >> 16;

 /* only the HDLCD_REG_FB_LINE_COUNT register has a limit */
 if (src_h >= HDLCD_MAX_YRES) {
  DRM_DEBUG_KMS("Invalid source width: %d\n", src_h);
  return -EINVAL;
 }

 for_each_new_crtc_in_state(state, crtc, crtc_state,
       i) {
  /* we cannot disable the plane while the CRTC is active */
  if (!new_plane_state->fb && crtc_state->active)
   return -EINVAL;
  return drm_atomic_helper_check_plane_state(new_plane_state,
          crtc_state,
          DRM_PLANE_NO_SCALING,
          DRM_PLANE_NO_SCALING,
          false, true);
 }

 return 0;
}

static void hdlcd_plane_atomic_update(struct drm_plane *plane,
          struct drm_atomic_state *state)
{
 struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
           plane);
 struct drm_framebuffer *fb = new_plane_state->fb;
 struct hdlcd_drm_private *hdlcd;
 u32 dest_h;
 dma_addr_t scanout_start;

 if (!fb)
  return;

 dest_h = drm_rect_height(&new_plane_state->dst);
 scanout_start = drm_fb_dma_get_gem_addr(fb, new_plane_state, 0);

 hdlcd = drm_to_hdlcd_priv(plane->dev);
 hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, fb->pitches[0]);
 hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, fb->pitches[0]);
 hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, dest_h - 1);
 hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
}

static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
 .atomic_check = hdlcd_plane_atomic_check,
 .atomic_update = hdlcd_plane_atomic_update,
};

static const struct drm_plane_funcs hdlcd_plane_funcs = {
 .update_plane  = drm_atomic_helper_update_plane,
 .disable_plane  = drm_atomic_helper_disable_plane,
 .reset   = drm_atomic_helper_plane_reset,
 .atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
 .atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
};

static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
{
 struct hdlcd_drm_private *hdlcd = drm_to_hdlcd_priv(drm);
 struct drm_plane *plane = NULL;
 u32 formats[ARRAY_SIZE(supported_formats)], i;

 for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
  formats[i] = supported_formats[i].fourcc;

 plane = drmm_universal_plane_alloc(drm, struct drm_plane, dev, 0xff,
        &hdlcd_plane_funcs,
        formats, ARRAY_SIZE(formats),
        NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
 if (IS_ERR(plane))
  return plane;

 drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
 hdlcd->plane = plane;

 return plane;
}

int hdlcd_setup_crtc(struct drm_device *drm)
{
 struct hdlcd_drm_private *hdlcd = drm_to_hdlcd_priv(drm);
 struct drm_plane *primary;
 int ret;

 primary = hdlcd_plane_init(drm);
 if (IS_ERR(primary))
  return PTR_ERR(primary);

 ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
     &hdlcd_crtc_funcs, NULL);
 if (ret)
  return ret;

 drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
 return 0;
}