drivers/video/fbdev/intelfb/intelfb_i2c.c

/**************************************************************************

 Copyright 2006 Dave Airlie <airlied@linux.ie>

All Rights Reserved.

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
on the rights to use, copy, modify, merge, publish, distribute, sub
license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
THE COPYRIGHT HOLDERS AND/OR THEIR SUPPLIERS 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.

**************************************************************************/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/pci.h>
#include <linux/fb.h>

#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>

#include <asm/io.h>

#include "intelfb.h"
#include "intelfbhw.h"

/* bit locations in the registers */
#define SCL_DIR_MASK		0x0001
#define SCL_DIR			0x0002
#define SCL_VAL_MASK		0x0004
#define SCL_VAL_OUT		0x0008
#define SCL_VAL_IN		0x0010
#define SDA_DIR_MASK		0x0100
#define SDA_DIR			0x0200
#define SDA_VAL_MASK		0x0400
#define SDA_VAL_OUT		0x0800
#define SDA_VAL_IN		0x1000

static void intelfb_gpio_setscl(void *data, int state)
{
	struct intelfb_i2c_chan *chan = data;
	struct intelfb_info *dinfo = chan->dinfo;
	u32 val;

	OUTREG(chan->reg, (state ? SCL_VAL_OUT : 0) |
	       SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK);
	val = INREG(chan->reg);
}

static void intelfb_gpio_setsda(void *data, int state)
{
	struct intelfb_i2c_chan *chan = data;
	struct intelfb_info *dinfo = chan->dinfo;
	u32 val;

	OUTREG(chan->reg, (state ? SDA_VAL_OUT : 0) |
	       SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK);
	val = INREG(chan->reg);
}

static int intelfb_gpio_getscl(void *data)
{
	struct intelfb_i2c_chan *chan = data;
	struct intelfb_info *dinfo = chan->dinfo;
	u32 val;

	OUTREG(chan->reg, SCL_DIR_MASK);
	OUTREG(chan->reg, 0);
	val = INREG(chan->reg);
	return ((val & SCL_VAL_IN) != 0);
}

static int intelfb_gpio_getsda(void *data)
{
	struct intelfb_i2c_chan *chan = data;
	struct intelfb_info *dinfo = chan->dinfo;
	u32 val;

	OUTREG(chan->reg, SDA_DIR_MASK);
	OUTREG(chan->reg, 0);
	val = INREG(chan->reg);
	return ((val & SDA_VAL_IN) != 0);
}

static int intelfb_setup_i2c_bus(struct intelfb_info *dinfo,
				 struct intelfb_i2c_chan *chan,
				 const u32 reg, const char *name,
				 int class)
{
	int rc;

	chan->dinfo			= dinfo;
	chan->reg			= reg;
	snprintf(chan->adapter.name, sizeof(chan->adapter.name),
		 "intelfb %s", name);
	chan->adapter.class		= class;
	chan->adapter.owner		= THIS_MODULE;
	chan->adapter.algo_data		= &chan->algo;
	chan->adapter.dev.parent	= &chan->dinfo->pdev->dev;
	chan->algo.setsda		= intelfb_gpio_setsda;
	chan->algo.setscl		= intelfb_gpio_setscl;
	chan->algo.getsda		= intelfb_gpio_getsda;
	chan->algo.getscl		= intelfb_gpio_getscl;
	chan->algo.udelay		= 40;
	chan->algo.timeout		= 20;
	chan->algo.data			= chan;

	i2c_set_adapdata(&chan->adapter, chan);

	/* Raise SCL and SDA */
	intelfb_gpio_setsda(chan, 1);
	intelfb_gpio_setscl(chan, 1);
	udelay(20);

	rc = i2c_bit_add_bus(&chan->adapter);
	if (rc == 0)
		DBG_MSG("I2C bus %s registered.\n", name);
	else
		WRN_MSG("Failed to register I2C bus %s.\n", name);
	return rc;
}

void intelfb_create_i2c_busses(struct intelfb_info *dinfo)
{
	int i = 0;

	/* everyone has at least a single analog output */
	dinfo->num_outputs = 1;
	dinfo->output[i].type = INTELFB_OUTPUT_ANALOG;

	/* setup the DDC bus for analog output */
	intelfb_setup_i2c_bus(dinfo, &dinfo->output[i].ddc_bus, GPIOA,
			      "CRTDDC_A", I2C_CLASS_DDC);
	i++;

	/* need to add the output busses for each device
	   - this function is very incomplete
	   - i915GM has LVDS and TVOUT for example
	*/
	switch(dinfo->chipset) {
	case INTEL_830M:
	case INTEL_845G:
	case INTEL_854:
	case INTEL_855GM:
	case INTEL_865G:
		dinfo->output[i].type = INTELFB_OUTPUT_DVO;
		intelfb_setup_i2c_bus(dinfo, &dinfo->output[i].ddc_bus,
				      GPIOD, "DVODDC_D", I2C_CLASS_DDC);
		intelfb_setup_i2c_bus(dinfo, &dinfo->output[i].i2c_bus,
				      GPIOE, "DVOI2C_E", 0);
		i++;
		break;
	case INTEL_915G:
	case INTEL_915GM:
		/* has some LVDS + tv-out */
	case INTEL_945G:
	case INTEL_945GM:
	case INTEL_945GME:
	case INTEL_965G:
	case INTEL_965GM:
		/* SDVO ports have a single control bus - 2 devices */
		dinfo->output[i].type = INTELFB_OUTPUT_SDVO;
		intelfb_setup_i2c_bus(dinfo, &dinfo->output[i].i2c_bus,
				      GPIOE, "SDVOCTRL_E", 0);
		/* TODO: initialize the SDVO */
		/* I830SDVOInit(pScrn, i, DVOB); */
		i++;

		/* set up SDVOC */
		dinfo->output[i].type = INTELFB_OUTPUT_SDVO;
		dinfo->output[i].i2c_bus = dinfo->output[i - 1].i2c_bus;
		/* TODO: initialize the SDVO */
		/* I830SDVOInit(pScrn, i, DVOC); */
		i++;
		break;
	}
	dinfo->num_outputs = i;
}

void intelfb_delete_i2c_busses(struct intelfb_info *dinfo)
{
	int i;

	for (i = 0; i < MAX_OUTPUTS; i++) {
		if (dinfo->output[i].i2c_bus.dinfo) {
			i2c_del_adapter(&dinfo->output[i].i2c_bus.adapter);
			dinfo->output[i].i2c_bus.dinfo = NULL;
		}
		if (dinfo->output[i].ddc_bus.dinfo) {
			i2c_del_adapter(&dinfo->output[i].ddc_bus.adapter);
			dinfo->output[i].ddc_bus.dinfo = NULL;
		}
	}
}