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f899fc64cd
Use the GMBUS interface rather than direct bit banging to grab the EDID over DDC (and for other forms of auxiliary communication with external display controllers). The hope is that this method will be much faster and more reliable than bit banging for fetching EDIDs from buggy monitors or through switches, though we still preserve the bit banging as a fallback in case GMBUS fails. Based on an original patch by Jesse Barnes. Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
83 lines
2.4 KiB
C
83 lines
2.4 KiB
C
/*
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* Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
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* Copyright (c) 2007, 2010 Intel Corporation
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* Jesse Barnes <jesse.barnes@intel.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*/
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/fb.h>
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#include "drmP.h"
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#include "intel_drv.h"
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#include "i915_drv.h"
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/**
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* intel_ddc_probe
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*
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*/
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bool intel_ddc_probe(struct intel_encoder *intel_encoder, int ddc_bus)
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{
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struct drm_i915_private *dev_priv = intel_encoder->base.dev->dev_private;
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u8 out_buf[] = { 0x0, 0x0};
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u8 buf[2];
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struct i2c_msg msgs[] = {
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{
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.addr = 0x50,
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.flags = 0,
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.len = 1,
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.buf = out_buf,
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},
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{
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.addr = 0x50,
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.flags = I2C_M_RD,
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.len = 1,
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.buf = buf,
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}
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};
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return i2c_transfer(&dev_priv->gmbus[ddc_bus].adapter, msgs, 2) == 2;
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}
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/**
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* intel_ddc_get_modes - get modelist from monitor
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* @connector: DRM connector device to use
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* @adapter: i2c adapter
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*
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* Fetch the EDID information from @connector using the DDC bus.
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*/
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int intel_ddc_get_modes(struct drm_connector *connector,
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struct i2c_adapter *adapter)
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{
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struct edid *edid;
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int ret = 0;
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edid = drm_get_edid(connector, adapter);
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if (edid) {
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drm_mode_connector_update_edid_property(connector, edid);
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ret = drm_add_edid_modes(connector, edid);
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connector->display_info.raw_edid = NULL;
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kfree(edid);
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}
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return ret;
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}
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