Quelle  tilcdc_panel.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 Texas Instruments
 * Author: Rob Clark <robdclark@gmail.com>
 */

#include <linux/backlight.h>
#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>

#include <video/display_timing.h>
#include <video/of_display_timing.h>
#include <video/videomode.h>

#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_connector.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>

#include "tilcdc_drv.h"
#include "tilcdc_panel.h"

struct panel_module {
 struct tilcdc_module base;
 struct tilcdc_panel_info *info;
 struct display_timings *timings;
 struct backlight_device *backlight;
 struct gpio_desc *enable_gpio;
};
#define to_panel_module(x) container_of(x, struct panel_module, base)


/*
 * Encoder:
 */

struct panel_encoder {
 struct drm_encoder base;
 struct panel_module *mod;
};
#define to_panel_encoder(x) container_of(x, struct panel_encoder, base)

static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
{
 struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
 struct backlight_device *backlight = panel_encoder->mod->backlight;
 struct gpio_desc *gpio = panel_encoder->mod->enable_gpio;

 if (backlight) {
  backlight->props.power = mode == DRM_MODE_DPMS_ON ?
      BACKLIGHT_POWER_ON : BACKLIGHT_POWER_OFF;
  backlight_update_status(backlight);
 }

 if (gpio)
  gpiod_set_value_cansleep(gpio,
      mode == DRM_MODE_DPMS_ON ? 1 : 0);
}

static void panel_encoder_prepare(struct drm_encoder *encoder)
{
 panel_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
}

static void panel_encoder_commit(struct drm_encoder *encoder)
{
 panel_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
}

static void panel_encoder_mode_set(struct drm_encoder *encoder,
  struct drm_display_mode *mode,
  struct drm_display_mode *adjusted_mode)
{
 /* nothing needed */
}

static const struct drm_encoder_helper_funcs panel_encoder_helper_funcs = {
  .dpms           = panel_encoder_dpms,
  .prepare        = panel_encoder_prepare,
  .commit         = panel_encoder_commit,
  .mode_set       = panel_encoder_mode_set,
};

static struct drm_encoder *panel_encoder_create(struct drm_device *dev,
  struct panel_module *mod)
{
 struct panel_encoder *panel_encoder;
 struct drm_encoder *encoder;
 int ret;

 panel_encoder = devm_kzalloc(dev->dev, sizeof(*panel_encoder),
         GFP_KERNEL);
 if (!panel_encoder)
  return NULL;

 panel_encoder->mod = mod;

 encoder = &panel_encoder->base;
 encoder->possible_crtcs = 1;

 ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_LVDS);
 if (ret < 0)
  goto fail;

 drm_encoder_helper_add(encoder, &panel_encoder_helper_funcs);

 return encoder;

fail:
 drm_encoder_cleanup(encoder);
 return NULL;
}

/*
 * Connector:
 */

struct panel_connector {
 struct drm_connector base;

 struct drm_encoder *encoder;  /* our connected encoder */
 struct panel_module *mod;
};
#define to_panel_connector(x) container_of(x, struct panel_connector, base)


static void panel_connector_destroy(struct drm_connector *connector)
{
 drm_connector_unregister(connector);
 drm_connector_cleanup(connector);
}

static int panel_connector_get_modes(struct drm_connector *connector)
{
 struct drm_device *dev = connector->dev;
 struct panel_connector *panel_connector = to_panel_connector(connector);
 struct display_timings *timings = panel_connector->mod->timings;
 int i;

 for (i = 0; i < timings->num_timings; i++) {
  struct drm_display_mode *mode;
  struct videomode vm;

  if (videomode_from_timings(timings, &vm, i))
   break;

  mode = drm_mode_create(dev);
  if (!mode)
   break;

  drm_display_mode_from_videomode(&vm, mode);

  mode->type = DRM_MODE_TYPE_DRIVER;

  if (timings->native_mode == i)
   mode->type |= DRM_MODE_TYPE_PREFERRED;

  drm_mode_set_name(mode);
  drm_mode_probed_add(connector, mode);
 }

 return i;
}

static struct drm_encoder *panel_connector_best_encoder(
  struct drm_connector *connector)
{
 struct panel_connector *panel_connector = to_panel_connector(connector);
 return panel_connector->encoder;
}

static const struct drm_connector_funcs panel_connector_funcs = {
 .destroy            = panel_connector_destroy,
 .fill_modes         = drm_helper_probe_single_connector_modes,
 .reset              = drm_atomic_helper_connector_reset,
 .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static const struct drm_connector_helper_funcs panel_connector_helper_funcs = {
 .get_modes          = panel_connector_get_modes,
 .best_encoder       = panel_connector_best_encoder,
};

static struct drm_connector *panel_connector_create(struct drm_device *dev,
  struct panel_module *mod, struct drm_encoder *encoder)
{
 struct panel_connector *panel_connector;
 struct drm_connector *connector;
 int ret;

 panel_connector = devm_kzalloc(dev->dev, sizeof(*panel_connector),
           GFP_KERNEL);
 if (!panel_connector)
  return NULL;

 panel_connector->encoder = encoder;
 panel_connector->mod = mod;

 connector = &panel_connector->base;

 drm_connector_init(dev, connector, &panel_connector_funcs,
   DRM_MODE_CONNECTOR_LVDS);
 drm_connector_helper_add(connector, &panel_connector_helper_funcs);

 connector->interlace_allowed = 0;
 connector->doublescan_allowed = 0;

 ret = drm_connector_attach_encoder(connector, encoder);
 if (ret)
  goto fail;

 return connector;

fail:
 panel_connector_destroy(connector);
 return NULL;
}

/*
 * Module:
 */

static int panel_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
{
 struct panel_module *panel_mod = to_panel_module(mod);
 struct tilcdc_drm_private *priv = dev->dev_private;
 struct drm_encoder *encoder;
 struct drm_connector *connector;

 encoder = panel_encoder_create(dev, panel_mod);
 if (!encoder)
  return -ENOMEM;

 connector = panel_connector_create(dev, panel_mod, encoder);
 if (!connector)
  return -ENOMEM;

 priv->encoders[priv->num_encoders++] = encoder;
 priv->connectors[priv->num_connectors++] = connector;

 tilcdc_crtc_set_panel_info(priv->crtc,
       to_panel_encoder(encoder)->mod->info);

 return 0;
}

static const struct tilcdc_module_ops panel_module_ops = {
  .modeset_init = panel_modeset_init,
};

/*
 * Device:
 */

/* maybe move this somewhere common if it is needed by other outputs? */
static struct tilcdc_panel_info *of_get_panel_info(struct device_node *np)
{
 struct device_node *info_np;
 struct tilcdc_panel_info *info;
 int ret = 0;

 if (!np) {
  pr_err("%s: no devicenode given\n", __func__);
  return NULL;
 }

 info_np = of_get_child_by_name(np, "panel-info");
 if (!info_np) {
  pr_err("%s: could not find panel-info node\n", __func__);
  return NULL;
 }

 info = kzalloc(sizeof(*info), GFP_KERNEL);
 if (!info)
  goto put_node;

 ret |= of_property_read_u32(info_np, "ac-bias", &info->ac_bias);
 ret |= of_property_read_u32(info_np, "ac-bias-intrpt", &info->ac_bias_intrpt);
 ret |= of_property_read_u32(info_np, "dma-burst-sz", &info->dma_burst_sz);
 ret |= of_property_read_u32(info_np, "bpp", &info->bpp);
 ret |= of_property_read_u32(info_np, "fdd", &info->fdd);
 ret |= of_property_read_u32(info_np, "sync-edge", &info->sync_edge);
 ret |= of_property_read_u32(info_np, "sync-ctrl", &info->sync_ctrl);
 ret |= of_property_read_u32(info_np, "raster-order", &info->raster_order);
 ret |= of_property_read_u32(info_np, "fifo-th", &info->fifo_th);

 /* optional: */
 info->tft_alt_mode      = of_property_read_bool(info_np, "tft-alt-mode");
 info->invert_pxl_clk    = of_property_read_bool(info_np, "invert-pxl-clk");

 if (ret) {
  pr_err("%s: error reading panel-info properties\n", __func__);
  kfree(info);
  info = NULL;
 }

put_node:
 of_node_put(info_np);
 return info;
}

static int panel_probe(struct platform_device *pdev)
{
 struct device_node *node = pdev->dev.of_node;
 struct backlight_device *backlight;
 struct panel_module *panel_mod;
 struct tilcdc_module *mod;
 int ret;

 /* bail out early if no DT data: */
 if (!node) {
  dev_err(&pdev->dev, "device-tree data is missing\n");
  return -ENXIO;
 }

 panel_mod = devm_kzalloc(&pdev->dev, sizeof(*panel_mod), GFP_KERNEL);
 if (!panel_mod)
  return -ENOMEM;

 backlight = devm_of_find_backlight(&pdev->dev);
 if (IS_ERR(backlight))
  return PTR_ERR(backlight);
 panel_mod->backlight = backlight;

 panel_mod->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
        GPIOD_OUT_LOW);
 if (IS_ERR(panel_mod->enable_gpio)) {
  ret = PTR_ERR(panel_mod->enable_gpio);
  dev_err(&pdev->dev, "failed to request enable GPIO\n");
  goto fail_backlight;
 }

 if (panel_mod->enable_gpio)
  dev_info(&pdev->dev, "found enable GPIO\n");

 mod = &panel_mod->base;
 pdev->dev.platform_data = mod;

 tilcdc_module_init(mod, "panel", &panel_module_ops);

 panel_mod->timings = of_get_display_timings(node);
 if (!panel_mod->timings) {
  dev_err(&pdev->dev, "could not get panel timings\n");
  ret = -EINVAL;
  goto fail_free;
 }

 panel_mod->info = of_get_panel_info(node);
 if (!panel_mod->info) {
  dev_err(&pdev->dev, "could not get panel info\n");
  ret = -EINVAL;
  goto fail_timings;
 }

 return 0;

fail_timings:
 display_timings_release(panel_mod->timings);

fail_free:
 tilcdc_module_cleanup(mod);

fail_backlight:
 if (panel_mod->backlight)
  put_device(&panel_mod->backlight->dev);
 return ret;
}

static void panel_remove(struct platform_device *pdev)
{
 struct tilcdc_module *mod = dev_get_platdata(&pdev->dev);
 struct panel_module *panel_mod = to_panel_module(mod);
 struct backlight_device *backlight = panel_mod->backlight;

 if (backlight)
  put_device(&backlight->dev);

 display_timings_release(panel_mod->timings);

 tilcdc_module_cleanup(mod);
 kfree(panel_mod->info);
}

static const struct of_device_id panel_of_match[] = {
  { .compatible = "ti,tilcdc,panel", },
  { },
};

static struct platform_driver panel_driver = {
 .probe = panel_probe,
 .remove = panel_remove,
 .driver = {
  .name = "tilcdc-panel",
  .of_match_table = panel_of_match,
 },
};

int __init tilcdc_panel_init(void)
{
 return platform_driver_register(&panel_driver);
}

void __exit tilcdc_panel_fini(void)
{
 platform_driver_unregister(&panel_driver);
}