Quelle  zynqmp_dpsub.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 * ZynqMP DisplayPort Subsystem Driver
 *
 * Copyright (C) 2017 - 2020 Xilinx, Inc.
 *
 * Authors:
 * - Hyun Woo Kwon <hyun.kwon@xilinx.com>
 * - Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/of_graph.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_modeset_helper.h>
#include <drm/drm_module.h>

#include "zynqmp_disp.h"
#include "zynqmp_dp.h"
#include "zynqmp_dpsub.h"
#include "zynqmp_kms.h"

/* -----------------------------------------------------------------------------
 * Power Management
 */

static int __maybe_unused zynqmp_dpsub_suspend(struct device *dev)
{
 struct zynqmp_dpsub *dpsub = dev_get_drvdata(dev);

 if (!dpsub->drm)
  return 0;

 return drm_mode_config_helper_suspend(&dpsub->drm->dev);
}

static int __maybe_unused zynqmp_dpsub_resume(struct device *dev)
{
 struct zynqmp_dpsub *dpsub = dev_get_drvdata(dev);

 if (!dpsub->drm)
  return 0;

 return drm_mode_config_helper_resume(&dpsub->drm->dev);
}

static const struct dev_pm_ops zynqmp_dpsub_pm_ops = {
 SET_SYSTEM_SLEEP_PM_OPS(zynqmp_dpsub_suspend, zynqmp_dpsub_resume)
};

/* -----------------------------------------------------------------------------
 * Probe & Remove
 */

static int zynqmp_dpsub_init_clocks(struct zynqmp_dpsub *dpsub)
{
 int ret;

 dpsub->apb_clk = devm_clk_get(dpsub->dev, "dp_apb_clk");
 if (IS_ERR(dpsub->apb_clk))
  return PTR_ERR(dpsub->apb_clk);

 ret = clk_prepare_enable(dpsub->apb_clk);
 if (ret) {
  dev_err(dpsub->dev, "failed to enable the APB clock\n");
  return ret;
 }

 /*
 * Try the live PL video clock, and fall back to the PS clock if the
 * live PL video clock isn't valid.
 */
 dpsub->vid_clk = devm_clk_get(dpsub->dev, "dp_live_video_in_clk");
 if (!IS_ERR(dpsub->vid_clk))
  dpsub->vid_clk_from_ps = false;
 else if (PTR_ERR(dpsub->vid_clk) == -EPROBE_DEFER)
  return PTR_ERR(dpsub->vid_clk);

 if (IS_ERR_OR_NULL(dpsub->vid_clk)) {
  dpsub->vid_clk = devm_clk_get(dpsub->dev, "dp_vtc_pixel_clk_in");
  if (IS_ERR(dpsub->vid_clk)) {
   dev_err(dpsub->dev, "failed to init any video clock\n");
   return PTR_ERR(dpsub->vid_clk);
  }
  dpsub->vid_clk_from_ps = true;
 }

 /*
 * Try the live PL audio clock, and fall back to the PS clock if the
 * live PL audio clock isn't valid. Missing audio clock disables audio
 * but isn't an error.
 */
 dpsub->aud_clk = devm_clk_get(dpsub->dev, "dp_live_audio_aclk");
 if (!IS_ERR(dpsub->aud_clk)) {
  dpsub->aud_clk_from_ps = false;
  return 0;
 }

 dpsub->aud_clk = devm_clk_get(dpsub->dev, "dp_aud_clk");
 if (!IS_ERR(dpsub->aud_clk)) {
  dpsub->aud_clk_from_ps = true;
  return 0;
 }

 dev_info(dpsub->dev, "audio disabled due to missing clock\n");
 return 0;
}

static int zynqmp_dpsub_parse_dt(struct zynqmp_dpsub *dpsub)
{
 struct device_node *np;
 unsigned int i;

 /*
 * For backward compatibility with old device trees that don't contain
 * ports, consider that only the DP output port is connected if no
 * ports child no exists.
 */
 np = of_get_child_by_name(dpsub->dev->of_node, "ports");
 of_node_put(np);
 if (!np) {
  dev_warn(dpsub->dev, "missing ports, update DT bindings\n");
  dpsub->connected_ports = BIT(ZYNQMP_DPSUB_PORT_OUT_DP);
  dpsub->dma_enabled = true;
  return 0;
 }

 /* Check which ports are connected. */
 for (i = 0; i < ZYNQMP_DPSUB_NUM_PORTS; ++i) {
  struct device_node *np;

  np = of_graph_get_remote_node(dpsub->dev->of_node, i, -1);
  if (np) {
   dpsub->connected_ports |= BIT(i);
   of_node_put(np);
  }
 }

 /* Sanity checks. */
 if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO)) &&
     (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))) {
  dev_err(dpsub->dev, "only one live video input is supported\n");
  return -EINVAL;
 }

 if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_VIDEO)) ||
     (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_GFX))) {
  if (dpsub->vid_clk_from_ps) {
   dev_err(dpsub->dev,
    "live video input requires PL clock\n");
   return -EINVAL;
  }
 } else {
  dpsub->dma_enabled = true;
 }

 if (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_LIVE_AUDIO))
  dev_warn(dpsub->dev, "live audio unsupported, ignoring\n");

 if ((dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_VIDEO)) ||
     (dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_AUDIO)))
  dev_warn(dpsub->dev, "output to PL unsupported, ignoring\n");

 if (!(dpsub->connected_ports & BIT(ZYNQMP_DPSUB_PORT_OUT_DP))) {
  dev_err(dpsub->dev, "DP output port not connected\n");
  return -EINVAL;
 }

 return 0;
}

void zynqmp_dpsub_release(struct zynqmp_dpsub *dpsub)
{
 kfree(dpsub->disp);
 kfree(dpsub);
}

static int zynqmp_dpsub_probe(struct platform_device *pdev)
{
 struct zynqmp_dpsub *dpsub;
 int ret;

 /* Allocate private data. */
 dpsub = kzalloc(sizeof(*dpsub), GFP_KERNEL);
 if (!dpsub)
  return -ENOMEM;

 dpsub->dev = &pdev->dev;
 platform_set_drvdata(pdev, dpsub);

 ret = dma_set_mask(dpsub->dev, DMA_BIT_MASK(ZYNQMP_DISP_MAX_DMA_BIT));
 if (ret)
  return ret;

 dma_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32));

 /* Try the reserved memory. Proceed if there's none. */
 of_reserved_mem_device_init(&pdev->dev);

 ret = zynqmp_dpsub_init_clocks(dpsub);
 if (ret < 0)
  goto err_mem;

 ret = zynqmp_dpsub_parse_dt(dpsub);
 if (ret < 0)
  goto err_mem;

 pm_runtime_enable(&pdev->dev);

 /*
 * DP should be probed first so that the zynqmp_disp can set the output
 * format accordingly.
 */
 ret = zynqmp_dp_probe(dpsub);
 if (ret)
  goto err_pm;

 ret = zynqmp_disp_probe(dpsub);
 if (ret)
  goto err_dp;

 drm_bridge_add(dpsub->bridge);

 if (dpsub->dma_enabled) {
  ret = zynqmp_dpsub_drm_init(dpsub);
  if (ret)
   goto err_disp;
 }

 ret = zynqmp_audio_init(dpsub);
 if (ret)
  goto err_drm_cleanup;

 dev_info(&pdev->dev, "ZynqMP DisplayPort Subsystem driver probed");

 return 0;

err_drm_cleanup:
 if (dpsub->drm)
  zynqmp_dpsub_drm_cleanup(dpsub);
err_disp:
 drm_bridge_remove(dpsub->bridge);
 zynqmp_disp_remove(dpsub);
err_dp:
 zynqmp_dp_remove(dpsub);
err_pm:
 pm_runtime_disable(&pdev->dev);
 clk_disable_unprepare(dpsub->apb_clk);
err_mem:
 of_reserved_mem_device_release(&pdev->dev);
 if (!dpsub->drm)
  zynqmp_dpsub_release(dpsub);
 return ret;
}

static void zynqmp_dpsub_remove(struct platform_device *pdev)
{
 struct zynqmp_dpsub *dpsub = platform_get_drvdata(pdev);

 zynqmp_audio_uninit(dpsub);

 if (dpsub->drm)
  zynqmp_dpsub_drm_cleanup(dpsub);

 drm_bridge_remove(dpsub->bridge);
 zynqmp_disp_remove(dpsub);
 zynqmp_dp_remove(dpsub);

 pm_runtime_disable(&pdev->dev);
 clk_disable_unprepare(dpsub->apb_clk);
 of_reserved_mem_device_release(&pdev->dev);

 if (!dpsub->drm)
  zynqmp_dpsub_release(dpsub);
}

static void zynqmp_dpsub_shutdown(struct platform_device *pdev)
{
 struct zynqmp_dpsub *dpsub = platform_get_drvdata(pdev);

 if (!dpsub->drm)
  return;

 drm_atomic_helper_shutdown(&dpsub->drm->dev);
}

static const struct of_device_id zynqmp_dpsub_of_match[] = {
 { .compatible = "xlnx,zynqmp-dpsub-1.7", },
 { /* end of table */ },
};
MODULE_DEVICE_TABLE(of, zynqmp_dpsub_of_match);

static struct platform_driver zynqmp_dpsub_driver = {
 .probe   = zynqmp_dpsub_probe,
 .remove   = zynqmp_dpsub_remove,
 .shutdown  = zynqmp_dpsub_shutdown,
 .driver   = {
  .name  = "zynqmp-dpsub",
  .pm  = &zynqmp_dpsub_pm_ops,
  .of_match_table = zynqmp_dpsub_of_match,
 },
};

drm_module_platform_driver(zynqmp_dpsub_driver);

MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("ZynqMP DP Subsystem Driver");
MODULE_LICENSE("GPL v2");