path: root/drivers/gpu/drm/i915/intel_sdvo.c

/*
 * Copyright 2006 Dave Airlie <airlied@linux.ie>
 * Copyright © 2006-2007 Intel Corporation
 *   Jesse Barnes <jesse.barnes@intel.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *	Eric Anholt <eric@anholt.net>
 */
#include <linux/i2c.h>
#include <linux/delay.h>
#include "drmP.h"
#include "drm.h"
#include "drm_crtc.h"
#include "intel_drv.h"
#include "i915_drm.h"
#include "i915_drv.h"
#include "intel_sdvo_regs.h"

#undef SDVO_DEBUG

struct intel_sdvo_priv {
	struct intel_i2c_chan *i2c_bus;
	int slaveaddr;
	int output_device;

	u16 active_outputs;

	struct intel_sdvo_caps caps;
	int pixel_clock_min, pixel_clock_max;

	int save_sdvo_mult;
	u16 save_active_outputs;
	struct intel_sdvo_dtd save_input_dtd_1, save_input_dtd_2;
	struct intel_sdvo_dtd save_output_dtd[16];
	u32 save_SDVOX;
};

/**
 * Writes the SDVOB or SDVOC with the given value, but always writes both
 * SDVOB and SDVOC to work around apparent hardware issues (according to
 * comments in the BIOS).
 */
static void intel_sdvo_write_sdvox(struct intel_output *intel_output, u32 val)
{
	struct drm_device *dev = intel_output->base.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_sdvo_priv   *sdvo_priv = intel_output->dev_priv;
	u32 bval = val, cval = val;
	int i;

	if (sdvo_priv->output_device == SDVOB) {
		cval = I915_READ(SDVOC);
	} else {
		bval = I915_READ(SDVOB);
	}
	/*
	 * Write the registers twice for luck. Sometimes,
	 * writing them only once doesn't appear to 'stick'.
	 * The BIOS does this too. Yay, magic
	 */
	for (i = 0; i < 2; i++)
	{
		I915_WRITE(SDVOB, bval);
		I915_READ(SDVOB);
		I915_WRITE(SDVOC, cval);
		I915_READ(SDVOC);
	}
}

static bool intel_sdvo_read_byte(struct intel_output *intel_output, u8 addr,
				 u8 *ch)
{
	struct intel_sdvo_priv *sdvo_priv = intel_output->dev_priv;
	u8 out_buf[2];
	u8 buf[2];
	int ret;

	struct i2c_msg msgs[] = {
		{
			.addr = sdvo_priv->i2c_bus->slave_addr,
			.flags = 0,
			.len = 1,
			.buf = out_buf,
		},
		{
			.addr = sdvo_priv->i2c_bus->slave_addr,
			.flags = I2C_M_RD,
			.len = 1,
			.buf = buf,
		}
	};

	out_buf[0] = addr;
	out_buf[1] = 0;

	if ((ret = i2c_transfer(&sdvo_priv->i2c_bus->adapter, msgs, 2)) == 2)
	{
		*ch = buf[0];
		return true;
	}

	DRM_DEBUG("i2c transfer returned %d\n", ret);
	return false;
}

static bool intel_sdvo_write_byte(struct intel_output *intel_output, int addr,
				  u8 ch)
{
	u8 out_buf[2];
	struct i2c_msg msgs[] = {
		{
			.addr = intel_output->i2c_bus->slave_addr,
			.flags = 0,
			.len <