path: root/drivers/gpu/drm/radeon/radeon_i2c.c

/*
 * Copyright 2007-8 Advanced Micro Devices, Inc.
 * Copyright 2008 Red Hat Inc.
 *
 * 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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: Dave Airlie
 *          Alex Deucher
 */
#include "drmP.h"
#include "radeon_drm.h"
#include "radeon.h"
#include "atom.h"

/**
 * radeon_ddc_probe
 *
 */
bool radeon_ddc_probe(struct radeon_connector *radeon_connector)
{
	u8 out_buf[] = { 0x0, 0x0};
	u8 buf[2];
	int ret;
	struct i2c_msg msgs[] = {
		{
			.addr = 0x50,
			.flags = 0,
			.len = 1,
			.buf = out_buf,
		},
		{
			.addr = 0x50,
			.flags = I2C_M_RD,
			.len = 1,
			.buf = buf,
		}
	};

	/* on hw with routers, select right port */
	if (radeon_connector->router.ddc_valid)
		radeon_router_select_ddc_port(radeon_connector);

	ret = i2c_transfer(&radeon_connector->ddc_bus->adapter, msgs, 2);
	if (ret == 2)
		return true;

	return false;
}

/* bit banging i2c */

static void radeon_i2c_do_lock(struct radeon_i2c_chan *i2c, int lock_state)
{
	struct radeon_device *rdev = i2c->dev->dev_private;
	struct radeon_i2c_bus_rec *rec = &i2c->rec;
	uint32_t temp;

	/* RV410 appears to have a bug where the hw i2c in reset
	 * holds the i2c port in a bad state - switch hw i2c away before
	 * doing DDC - do this for all r200s/r300s/r400s for safety sake
	 */
	if (rec->hw_capable) {
		if ((rdev->family >= CHIP_R200) && !ASIC_IS_AVIVO(rdev)) {
			u32 reg;

			if (rdev->family >= CHIP_RV350)
				reg = RADEON_GPIO_MONID;
			else if ((rdev->family == CHIP_R300) ||
				 (rdev->family == CHIP_R350))
				reg = RADEON_GPIO_DVI_DDC;
			else
				reg = RADEON_GPIO_CRT2_DDC;

			mutex_lock(&rdev->dc_hw_i2c_mutex);
			if (rec->a_clk_reg == reg) {
				WREG32(RADEON_DVI_I2C_CNTL_0, (RADEON_I2C_SOFT_RST |
							       R200_DVI_I2C_PIN_SEL(R200_SEL_DDC1)));
			} else {
				WREG32(RADEON_DVI_I2C_CNTL_0, (RADEON_I2C_SOFT_RST |
							       R200_DVI_I2C_PIN_SEL(R200_SEL_DDC3)));
			}
			mutex_unlock(&rdev->dc_hw_i2c_mutex);
		}
	}

	/* switch the pads to ddc mode */
	if (ASIC_IS_DCE3(rdev) && rec->hw_capable) {
		temp = RREG32(rec->mask_clk_reg);
		temp &= ~(1 << 16);
		WREG32(rec->mask_clk_reg, temp);
	}

	/* clear the output pin values */
	temp = RREG32(rec->a_clk_reg) & ~rec->a_clk_mask;
	WREG32(rec->a_clk_reg, temp);

	temp = RREG32(rec->a_data_reg) & ~rec->a_data_mask;
	WREG32(rec->a_data_reg, temp);

	/* set the pins to input */
	temp = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
	WREG32(rec->en_clk_reg,