rivafb-i2c.c

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/*
 * linux/drivers/video/riva/fbdev-i2c.c - nVidia i2c
 *
 * Maintained by Ani Joshi <[email protected]>
 *
 * Copyright 2004 Antonino A. Daplas <adaplas @pol.net>
 *
 * Based on radeonfb-i2c.c
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

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

#include <asm/io.h>

#include "rivafb.h"
#include "../edid.h"

static void riva_gpio_setscl(void* data, int state)
{
    struct riva_i2c_chan    *chan = data;
    struct riva_par     *par = chan->par;
    u32         val;

    VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
    val = VGA_RD08(par->riva.PCIO, 0x3d5) & 0xf0;

    if (state)
        val |= 0x20;
    else
        val &= ~0x20;

    VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
    VGA_WR08(par->riva.PCIO, 0x3d5, val | 0x1);
}

static void riva_gpio_setsda(void* data, int state)
{
    struct riva_i2c_chan    *chan = data;
    struct riva_par     *par = chan->par;
    u32         val;

    VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
    val = VGA_RD08(par->riva.PCIO, 0x3d5) & 0xf0;

    if (state)
        val |= 0x10;
    else
        val &= ~0x10;

    VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base + 1);
    VGA_WR08(par->riva.PCIO, 0x3d5, val | 0x1);
}

static int riva_gpio_getscl(void* data)
{
    struct riva_i2c_chan    *chan = data;
    struct riva_par     *par = chan->par;
    u32         val = 0;

    VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base);
    if (VGA_RD08(par->riva.PCIO, 0x3d5) & 0x04)
        val = 1;

    return val;
}

static int riva_gpio_getsda(void* data)
{
    struct riva_i2c_chan    *chan = data;
    struct riva_par     *par = chan->par;
    u32         val = 0;

    VGA_WR08(par->riva.PCIO, 0x3d4, chan->ddc_base);
    if (VGA_RD08(par->riva.PCIO, 0x3d5) & 0x08)
        val = 1;

    return val;
}

static int __devinit riva_setup_i2c_bus(struct riva_i2c_chan *chan,
                    const char *name,
                    unsigned int i2c_class)
{
    int rc;

    strcpy(chan->adapter.name, name);
    chan->adapter.owner     = THIS_MODULE;
    chan->adapter.class     = i2c_class;
    chan->adapter.algo_data     = &chan->algo;
    chan->adapter.dev.parent    = &chan->par->pdev->dev;
    chan->algo.setsda       = riva_gpio_setsda;
    chan->algo.setscl       = riva_gpio_setscl;
    chan->algo.getsda       = riva_gpio_getsda;
    chan->algo.getscl       = riva_gpio_getscl;
    chan->algo.udelay       = 40;
    chan->algo.timeout      = msecs_to_jiffies(2);
    chan->algo.data         = chan;

    i2c_set_adapdata(&chan->adapter, chan);

    /* Raise SCL and SDA */
    riva_gpio_setsda(chan, 1);
    riva_gpio_setscl(chan, 1);
    udelay(20);

    rc = i2c_bit_add_bus(&chan->adapter);
    if (rc == 0)
        dev_dbg(&chan->par->pdev->dev, "I2C bus %s registered.\n", name);
    else {
        dev_warn(&chan->par->pdev->dev,
             "Failed to register I2C bus %s.\n", name);
        chan->par = NULL;
    }

    return rc;
}

void __devinit riva_create_i2c_busses(struct riva_par *par)
{
    par->chan[0].par    = par;
    par->chan[1].par    = par;
    par->chan[2].par        = par;

    par->chan[0].ddc_base = 0x36;
    par->chan[1].ddc_base = 0x3e;
    par->chan[2].ddc_base = 0x50;
    riva_setup_i2c_bus(&par->chan[0], "BUS1", I2C_CLASS_HWMON);
    riva_setup_i2c_bus(&par->chan[1], "BUS2", 0);
    riva_setup_i2c_bus(&par->chan[2], "BUS3", 0);
}

void riva_delete_i2c_busses(struct riva_par *par)
{
    int i;

    for (i = 0; i < 3; i++) {
        if (!par->chan[i].par)
            continue;
        i2c_del_adapter(&par->chan[i].adapter);
        par->chan[i].par = NULL;
    }
}

int __devinit riva_probe_i2c_connector(struct riva_par *par, int conn, u8 **out_edid)
{
    u8 *edid = NULL;

    if (par->chan[conn].par)
        edid = fb_ddc_read(&par->chan[conn].adapter);

    if (out_edid)
        *out_edid = edid;
    if (!edid)
        return 1;

    return 0;
}