// SPDX-License-Identifier: GPL-2.0-only

/*

 * OF helpers for parsing display timings

 *

 * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix

 *

 * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de>

 */

#include <common.h>

#include <of.h>

#include <fb.h>

#include <malloc.h>

void display_timings_release(struct display_timings *disp)

{

  if (disp->modes)

    free(disp->modes);

  free(disp);

}

EXPORT_SYMBOL_GPL(display_timings_release);

/**

 * parse_timing_property - parse timing_entry from device_node

 * @np: device_node with the property

 * @name: name of the property

 * @result: will be set to the return value

 *

 * DESCRIPTION:

 * Every display_timing can be specified with either just the typical value or

 * a range consisting of min/typ/max. This function helps handling this

 **/

static int parse_timing_property(const struct device_node *np, const char *name,

        u32 *res)

{

  struct property *prop;

  int length, cells, ret;

  prop = of_find_property(np, name, &length);

  if (!prop) {

    pr_err("%pOF: could not find property %s\n",

      np, name);

    return -EINVAL;

  }

  cells = length / sizeof(u32);

  if ((cells == 1) || (cells == 3)) {

    ret = of_property_read_u32(np, name, res);

  } else {

    pr_err("%pOF: illegal timing specification in %s\n",

      np, name);

    return -EINVAL;

  }

  return ret;

}

/**

 * of_parse_display_timing - parse display_timing entry from device_node

 * @np: device_node with the properties

 **/

static int of_parse_display_timing(const struct device_node *np,

    struct fb_videomode *mode)

{

  u32 val = 0, pixelclock = 0;

  int ret = 0;

  memset(mode, 0, sizeof(*mode));

  ret |= parse_timing_property(np, "hback-porch", &mode->left_margin);

  ret |= parse_timing_property(np, "hfront-porch", &mode->right_margin);

  ret |= parse_timing_property(np, "hactive", &mode->xres);

  ret |= parse_timing_property(np, "hsync-len", &mode->hsync_len);

  ret |= parse_timing_property(np, "vback-porch", &mode->upper_margin);

  ret |= parse_timing_property(np, "vfront-porch", &mode->lower_margin);

  ret |= parse_timing_property(np, "vactive", &mode->yres);

  ret |= parse_timing_property(np, "vsync-len", &mode->vsync_len);

  ret |= parse_timing_property(np, "clock-frequency", &pixelclock);

  fb_videomode_set_pixclock_hz(mode, pixelclock);

  if (!of_property_read_u32(np, "vsync-active", &val))

    mode->sync |= val ? FB_SYNC_VERT_HIGH_ACT : 0;

  if (!of_property_read_u32(np, "hsync-active", &val))

    mode->sync |= val ? FB_SYNC_HOR_HIGH_ACT : 0;

  if (!of_property_read_u32(np, "de-active", &val))

    mode->display_flags |= val ? DISPLAY_FLAGS_DE_HIGH :

        DISPLAY_FLAGS_DE_LOW;

  if (!of_property_read_u32(np, "pixelclk-active", &val))

    mode->display_flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :

        DISPLAY_FLAGS_PIXDATA_NEGEDGE;

  if (ret) {

    pr_err("%pOF: error reading timing properties\n", np);

    return -EINVAL;

  }

  return 0;

}

/**

 * of_get_display_timing - parse a display_timing entry

 * @np: device_node with the timing subnode

 * @name: name of the timing node

 * @mode: fb_videomode struct to fill

 **/

int of_get_display_timing(const struct device_node *np, const char *name,

        struct fb_videomode *mode)

{

  struct device_node *timing_np;

  if (!np)

    return -EINVAL;

  timing_np = of_get_child_by_name(np, name);

  if (!timing_np)

    return -ENOENT;

  return of_parse_display_timing(timing_np, mode);

}

EXPORT_SYMBOL_GPL(of_get_display_timing);

/**

 * of_get_display_timings - parse all display_timing entries from a device_node

 * @np: device_node with the subnodes

 **/

struct display_timings *of_get_display_timings(struct device_node *np)

{

  struct device_node *timings_np;

  struct device_node *entry;

  struct device_node *native_mode;

  struct display_timings *disp;

  if (!np)

    return NULL;

  timings_np = of_get_child_by_name(np, "display-timings");

  if (!timings_np) {

    pr_debug("%pOF: could not find display-timings node\n", np);

    return NULL;

  }

  disp = xzalloc(sizeof(*disp));

  entry = of_parse_phandle(timings_np, "native-mode", 0);

  /* assume first child as native mode if none provided */

  if (!entry)

    entry = of_get_next_available_child(np, NULL);

  /* if there is no child, it is useless to go on */

  if (!entry) {

    pr_err("%pOF: no timing specifications given\n", np);

    goto fail;

  }

  pr_debug("%pOF: using %s as default timing\n",

    np, entry->name);

  native_mode = entry;

  disp->num_modes = of_get_child_count(timings_np);

  if (disp->num_modes == 0) {

    /* should never happen, as entry was already found above */

    pr_err("%pOF: no timings specified\n", np);

    goto fail;

  }

  disp->modes = xzalloc(sizeof(struct fb_videomode) * disp->num_modes);

  disp->num_modes = 0;

  disp->native_mode = 0;

  for_each_child_of_node(timings_np, entry) {

    struct fb_videomode *mode;

    int r;

    mode = &disp->modes[disp->num_modes];

    r = of_parse_display_timing(entry, mode);

    if (r) {

      /*

       * to not encourage wrong devicetrees, fail in case of

       * an error

       */

      pr_err("%pOF: error in timing %d\n",

        np, disp->num_modes + 1);

      goto fail;

    }

    mode->name = xstrdup(entry->name);

    if (native_mode == entry)

      disp->native_mode = disp->num_modes;

    disp->num_modes++;

  }

  pr_debug("%pOF: got %d timings. Using timing #%d as default\n",

    np, disp->num_modes,

    disp->native_mode + 1);

  return disp;

fail:

  display_timings_release(disp);

  return NULL;

}

EXPORT_SYMBOL_GPL(of_get_display_timings);