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/*

    i2c-i810.c - Part of lm_sensors, Linux kernel modules for hardware

              monitoring

    Copyright (c) 1998, 1999, 2000  Frodo Looijaard <frodol@dds.nl>,

    Philip Edelbrock <phil@netroedge.com>,

    Ralph Metzler <rjkm@thp.uni-koeln.de>, and

    Mark D. Studebaker <mdsxyz123@yahoo.com>

    Based on code written by Ralph Metzler <rjkm@thp.uni-koeln.de> and

    Simon Vogl

    This program is free software; you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation; either version 2 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

/*

   This interfaces to the I810/I815 to provide access to

   the DDC Bus and the I2C Bus.

   SUPPORTED DEVICES    PCI ID

   i810AA               7121          

   i810AB               7123          

   i810E                7125          

   i815                 1132          

*/

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/pci.h>

#include <linux/i2c.h>

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

#include <asm/io.h>

/* GPIO register locations */

#define I810_IOCONTROL_OFFSET   0x5000

#define I810_HVSYNC             0x00    /* not used */

#define I810_GPIOA              0x10

#define I810_GPIOB              0x14

/* 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

/* initialization states */

#define INIT1                   0x1

#define INIT2                   0x2

#define INIT3                   0x4

/* delays */

#define CYCLE_DELAY             10

#define TIMEOUT                 (HZ / 2)

static void *ioaddr;

/* The i810 GPIO registers have individual masks for each bit

   so we never have to read before writing. Nice. */

static void bit_i810i2c_setscl(void *data, int val)

{

        writel((val ? SCL_VAL_OUT : 0) | SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK,

             ioaddr + I810_GPIOB);

        readl(ioaddr + I810_GPIOB);     /* flush posted write */

}

static void bit_i810i2c_setsda(void *data, int val)

{

        writel((val ? SDA_VAL_OUT : 0) | SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK,

             ioaddr + I810_GPIOB);

        readl(ioaddr + I810_GPIOB);     /* flush posted write */

}

/* The GPIO pins are open drain, so the pins could always remain outputs.

   However, some chip versions don't latch the inputs unless they

   are set as inputs.

   We rely on the i2c-algo-bit routines to set the pins high before

   reading the input from other chips. Following guidance in the 815

   prog. ref. guide, we do a "dummy write" of 0 to the register before

   reading which forces the input value to be latched. We presume this

   applies to the 810 as well; shouldn't hurt anyway. This is necessary to get

   i2c_algo_bit bit_test=1 to pass. */

static int bit_i810i2c_getscl(void *data)

{

        writel(SCL_DIR_MASK, ioaddr + I810_GPIOB);

        writel(0, ioaddr + I810_GPIOB);

        return (0 != (readl(ioaddr + I810_GPIOB) & SCL_VAL_IN));

}

static int bit_i810i2c_getsda(void *data)

{

        writel(SDA_DIR_MASK, ioaddr + I810_GPIOB);

        writel(0, ioaddr + I810_GPIOB);

        return (0 != (readl(ioaddr + I810_GPIOB) & SDA_VAL_IN));

}

static void bit_i810ddc_setscl(void *data, int val)

{

        writel((val ? SCL_VAL_OUT : 0) | SCL_DIR | SCL_DIR_MASK | SCL_VAL_MASK,

             ioaddr + I810_GPIOA);

        readl(ioaddr + I810_GPIOA);     /* flush posted write */

}

static void bit_i810ddc_setsda(void *data, int val)

{

        writel((val ? SDA_VAL_OUT : 0) | SDA_DIR | SDA_DIR_MASK | SDA_VAL_MASK,

             ioaddr + I810_GPIOA);

        readl(ioaddr + I810_GPIOA);     /* flush posted write */

}

static int bit_i810ddc_getscl(void *data)

{

        writel(SCL_DIR_MASK, ioaddr + I810_GPIOA);

        writel(0, ioaddr + I810_GPIOA);

        return (0 != (readl(ioaddr + I810_GPIOA) & SCL_VAL_IN));

}

static int bit_i810ddc_getsda(void *data)

{

        writel(SDA_DIR_MASK, ioaddr + I810_GPIOA);

        writel(0, ioaddr + I810_GPIOA);

        return (0 != (readl(ioaddr + I810_GPIOA) & SDA_VAL_IN));

}

static int config_i810(struct pci_dev *dev)

{

        unsigned long cadr;

        /* map I810 memory */

        cadr = dev->resource[1].start;

        cadr += I810_IOCONTROL_OFFSET;

        cadr &= PCI_BASE_ADDRESS_MEM_MASK;

        ioaddr = ioremap_nocache(cadr, 0x1000);

        if (ioaddr) {

                bit_i810i2c_setscl(NULL, 1);

                bit_i810i2c_setsda(NULL, 1);

                bit_i810ddc_setscl(NULL, 1);

                bit_i810ddc_setsda(NULL, 1);

                return 0;

        }

        return -ENODEV;

}

static struct i2c_algo_bit_data i810_i2c_bit_data = {

        .setsda         = bit_i810i2c_setsda,

        .setscl         = bit_i810i2c_setscl,

        .getsda         = bit_i810i2c_getsda,

        .getscl         = bit_i810i2c_getscl,

        .udelay         = CYCLE_DELAY,

        .mdelay         = CYCLE_DELAY,

        .timeout        = TIMEOUT,

};

static struct i2c_adapter i810_i2c_adapter = {

        .owner          = THIS_MODULE,

        .name           = "I810/I815 I2C Adapter",

        .algo_data      = &i810_i2c_bit_data,

};

static struct i2c_algo_bit_data i810_ddc_bit_data = {

        .setsda         = bit_i810ddc_setsda,

        .setscl         = bit_i810ddc_setscl,

        .getsda         = bit_i810ddc_getsda,

        .getscl         = bit_i810ddc_getscl,

        .udelay         = CYCLE_DELAY,

        .mdelay         = CYCLE_DELAY,

        .timeout        = TIMEOUT,

};

static struct i2c_adapter i810_ddc_adapter = {

        .owner          = THIS_MODULE,

        .name           = "I810/I815 DDC Adapter",

        .algo_data      = &i810_ddc_bit_data,

};

static struct pci_device_id i810_ids[] __devinitdata = {

        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810_IG1) },

        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810_IG3) },

        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82810E_IG) },

        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82815_CGC) },

        { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82845G_IG) },

        { 0, },

};

static int __devinit i810_probe(struct pci_dev *dev, const struct pci_device_id *id)

{

        int retval;

        retval = config_i810(dev);

        if (retval)

                return retval;

        dev_info(&dev->dev, "i810/i815 i2c device found.\n");

        /* set up the sysfs linkage to our parent device */

        i810_i2c_adapter.dev.parent = &dev->dev;

        i810_ddc_adapter.dev.parent = &dev->dev;

        retval = i2c_bit_add_bus(&i810_i2c_adapter);

        if (retval)

                return retval;

        retval = i2c_bit_add_bus(&i810_ddc_adapter);

        if (retval)

                i2c_bit_del_bus(&i810_i2c_adapter);

        return retval;

}

static void __devexit i810_remove(struct pci_dev *dev)

{

        i2c_bit_del_bus(&i810_ddc_adapter);

        i2c_bit_del_bus(&i810_i2c_adapter);

        iounmap(ioaddr);

}

static struct pci_driver i810_driver = {

        .name           = "i810 smbus",

        .id_table       = i810_ids,

        .probe          = i810_probe,

        .remove         = __devexit_p(i810_remove),

};

static int __init i2c_i810_init(void)

{

        return pci_module_init(&i810_driver);

}

static void __exit i2c_i810_exit(void)

{

        pci_unregister_driver(&i810_driver);

}

MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>, "

                "Philip Edelbrock <phil@netroedge.com>, "

                "Ralph Metzler <rjkm@thp.uni-koeln.de>, "

                "and Mark D. Studebaker <mdsxyz123@yahoo.com>");

MODULE_DESCRIPTION("I810/I815 I2C/DDC driver");

MODULE_LICENSE("GPL");

module_init(i2c_i810_init);

module_exit(i2c_i810_exit);