Quelle  connector-dvi.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic DVI Connector driver
 *
 * Copyright (C) 2013 Texas Instruments
 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
 */

#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <drm/drm_edid.h>

#include <video/omapfb_dss.h>

static const struct omap_video_timings dvic_default_timings = {
 .x_res  = 640,
 .y_res  = 480,

 .pixelclock = 23500000,

 .hfp  = 48,
 .hsw  = 32,
 .hbp  = 80,

 .vfp  = 3,
 .vsw  = 4,
 .vbp  = 7,

 .vsync_level = OMAPDSS_SIG_ACTIVE_HIGH,
 .hsync_level = OMAPDSS_SIG_ACTIVE_HIGH,
 .data_pclk_edge = OMAPDSS_DRIVE_SIG_RISING_EDGE,
 .de_level = OMAPDSS_SIG_ACTIVE_HIGH,
 .sync_pclk_edge = OMAPDSS_DRIVE_SIG_FALLING_EDGE,
};

struct panel_drv_data {
 struct omap_dss_device dssdev;
 struct omap_dss_device *in;

 struct omap_video_timings timings;

 struct i2c_adapter *i2c_adapter;
};

#define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)

static int dvic_connect(struct omap_dss_device *dssdev)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);
 struct omap_dss_device *in = ddata->in;

 if (omapdss_device_is_connected(dssdev))
  return 0;

 return in->ops.dvi->connect(in, dssdev);
}

static void dvic_disconnect(struct omap_dss_device *dssdev)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);
 struct omap_dss_device *in = ddata->in;

 if (!omapdss_device_is_connected(dssdev))
  return;

 in->ops.dvi->disconnect(in, dssdev);
}

static int dvic_enable(struct omap_dss_device *dssdev)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);
 struct omap_dss_device *in = ddata->in;
 int r;

 if (!omapdss_device_is_connected(dssdev))
  return -ENODEV;

 if (omapdss_device_is_enabled(dssdev))
  return 0;

 in->ops.dvi->set_timings(in, &ddata->timings);

 r = in->ops.dvi->enable(in);
 if (r)
  return r;

 dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;

 return 0;
}

static void dvic_disable(struct omap_dss_device *dssdev)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);
 struct omap_dss_device *in = ddata->in;

 if (!omapdss_device_is_enabled(dssdev))
  return;

 in->ops.dvi->disable(in);

 dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
}

static void dvic_set_timings(struct omap_dss_device *dssdev,
  struct omap_video_timings *timings)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);
 struct omap_dss_device *in = ddata->in;

 ddata->timings = *timings;
 dssdev->panel.timings = *timings;

 in->ops.dvi->set_timings(in, timings);
}

static void dvic_get_timings(struct omap_dss_device *dssdev,
  struct omap_video_timings *timings)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);

 *timings = ddata->timings;
}

static int dvic_check_timings(struct omap_dss_device *dssdev,
  struct omap_video_timings *timings)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);
 struct omap_dss_device *in = ddata->in;

 return in->ops.dvi->check_timings(in, timings);
}

static int dvic_ddc_read(struct i2c_adapter *adapter,
  unsigned char *buf, u16 count, u8 offset)
{
 int r, retries;

 for (retries = 3; retries > 0; retries--) {
  struct i2c_msg msgs[] = {
   {
    .addr   = DDC_ADDR,
    .flags  = 0,
    .len    = 1,
    .buf    = &offset,
   }, {
    .addr   = DDC_ADDR,
    .flags  = I2C_M_RD,
    .len    = count,
    .buf    = buf,
   }
  };

  r = i2c_transfer(adapter, msgs, 2);
  if (r == 2)
   return 0;

  if (r != -EAGAIN)
   break;
 }

 return r < 0 ? r : -EIO;
}

static int dvic_read_edid(struct omap_dss_device *dssdev,
  u8 *edid, int len)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);
 int r, l, bytes_read;

 if (!ddata->i2c_adapter)
  return -ENODEV;

 l = min(EDID_LENGTH, len);
 r = dvic_ddc_read(ddata->i2c_adapter, edid, l, 0);
 if (r)
  return r;

 bytes_read = l;

 /* if there are extensions, read second block */
 if (len > EDID_LENGTH && edid[0x7e] > 0) {
  l = min(EDID_LENGTH, len - EDID_LENGTH);

  r = dvic_ddc_read(ddata->i2c_adapter, edid + EDID_LENGTH,
    l, EDID_LENGTH);
  if (r)
   return r;

  bytes_read += l;
 }

 return bytes_read;
}

static bool dvic_detect(struct omap_dss_device *dssdev)
{
 struct panel_drv_data *ddata = to_panel_data(dssdev);
 unsigned char out;
 int r;

 if (!ddata->i2c_adapter)
  return true;

 r = dvic_ddc_read(ddata->i2c_adapter, &out, 1, 0);

 return r == 0;
}

static struct omap_dss_driver dvic_driver = {
 .connect = dvic_connect,
 .disconnect = dvic_disconnect,

 .enable  = dvic_enable,
 .disable = dvic_disable,

 .set_timings = dvic_set_timings,
 .get_timings = dvic_get_timings,
 .check_timings = dvic_check_timings,

 .get_resolution = omapdss_default_get_resolution,

 .read_edid = dvic_read_edid,
 .detect  = dvic_detect,
};

static int dvic_probe_of(struct platform_device *pdev)
{
 struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 struct device_node *node = pdev->dev.of_node;
 struct omap_dss_device *in;
 struct device_node *adapter_node;
 struct i2c_adapter *adapter;

 in = omapdss_of_find_source_for_first_ep(node);
 if (IS_ERR(in)) {
  dev_err(&pdev->dev, "failed to find video source\n");
  return PTR_ERR(in);
 }

 ddata->in = in;

 adapter_node = of_parse_phandle(node, "ddc-i2c-bus", 0);
 if (adapter_node) {
  adapter = of_get_i2c_adapter_by_node(adapter_node);
  of_node_put(adapter_node);
  if (adapter == NULL) {
   dev_err(&pdev->dev, "failed to parse ddc-i2c-bus\n");
   omap_dss_put_device(ddata->in);
   return -EPROBE_DEFER;
  }

  ddata->i2c_adapter = adapter;
 }

 return 0;
}

static int dvic_probe(struct platform_device *pdev)
{
 struct panel_drv_data *ddata;
 struct omap_dss_device *dssdev;
 int r;

 if (!pdev->dev.of_node)
  return -ENODEV;

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

 platform_set_drvdata(pdev, ddata);

 r = dvic_probe_of(pdev);
 if (r)
  return r;

 ddata->timings = dvic_default_timings;

 dssdev = &ddata->dssdev;
 dssdev->driver = &dvic_driver;
 dssdev->dev = &pdev->dev;
 dssdev->type = OMAP_DISPLAY_TYPE_DVI;
 dssdev->owner = THIS_MODULE;
 dssdev->panel.timings = dvic_default_timings;

 r = omapdss_register_display(dssdev);
 if (r) {
  dev_err(&pdev->dev, "Failed to register panel\n");
  goto err_reg;
 }

 return 0;

err_reg:
 omap_dss_put_device(ddata->in);

 i2c_put_adapter(ddata->i2c_adapter);

 return r;
}

static void dvic_remove(struct platform_device *pdev)
{
 struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 struct omap_dss_device *dssdev = &ddata->dssdev;
 struct omap_dss_device *in = ddata->in;

 omapdss_unregister_display(&ddata->dssdev);

 dvic_disable(dssdev);
 dvic_disconnect(dssdev);

 omap_dss_put_device(in);

 i2c_put_adapter(ddata->i2c_adapter);
}

static const struct of_device_id dvic_of_match[] = {
 { .compatible = "omapdss,dvi-connector", },
 {},
};

MODULE_DEVICE_TABLE(of, dvic_of_match);

static struct platform_driver dvi_connector_driver = {
 .probe = dvic_probe,
 .remove = dvic_remove,
 .driver = {
  .name = "connector-dvi",
  .of_match_table = dvic_of_match,
 },
};

module_platform_driver(dvi_connector_driver);

MODULE_AUTHOR("Tomi Valkeinen ");
MODULE_DESCRIPTION("Generic DVI Connector driver");
MODULE_LICENSE("GPL");