i2c-hydra.c

Go to the documentation of this file.

/*
    i2c Support for the Apple `Hydra' Mac I/O

    Copyright (c) 1999-2004 Geert Uytterhoeven <[email protected]>

    Based on i2c Support for Via Technologies 82C586B South Bridge
    Copyright (c) 1998, 1999 Kyösti Mälkki <[email protected]>

    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.
*/

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <linux/init.h>
#include <linux/io.h>
#include <asm/hydra.h>


#define HYDRA_CPD_PD0   0x00000001  /* CachePD lines */
#define HYDRA_CPD_PD1   0x00000002
#define HYDRA_CPD_PD2   0x00000004
#define HYDRA_CPD_PD3   0x00000008

#define HYDRA_SCLK  HYDRA_CPD_PD0
#define HYDRA_SDAT  HYDRA_CPD_PD1
#define HYDRA_SCLK_OE   0x00000010
#define HYDRA_SDAT_OE   0x00000020

static inline void pdregw(void *data, u32 val)
{
    struct Hydra *hydra = (struct Hydra *)data;
    writel(val, &hydra->CachePD);
}

static inline u32 pdregr(void *data)
{
    struct Hydra *hydra = (struct Hydra *)data;
    return readl(&hydra->CachePD);
}

static void hydra_bit_setscl(void *data, int state)
{
    u32 val = pdregr(data);
    if (state)
        val &= ~HYDRA_SCLK_OE;
    else {
        val &= ~HYDRA_SCLK;
        val |= HYDRA_SCLK_OE;
    }
    pdregw(data, val);
}

static void hydra_bit_setsda(void *data, int state)
{
    u32 val = pdregr(data);
    if (state)
        val &= ~HYDRA_SDAT_OE;
    else {
        val &= ~HYDRA_SDAT;
        val |= HYDRA_SDAT_OE;
    }
    pdregw(data, val);
}

static int hydra_bit_getscl(void *data)
{
    return (pdregr(data) & HYDRA_SCLK) != 0;
}

static int hydra_bit_getsda(void *data)
{
    return (pdregr(data) & HYDRA_SDAT) != 0;
}

/* ------------------------------------------------------------------------ */

static struct i2c_algo_bit_data hydra_bit_data = {
    .setsda     = hydra_bit_setsda,
    .setscl     = hydra_bit_setscl,
    .getsda     = hydra_bit_getsda,
    .getscl     = hydra_bit_getscl,
    .udelay     = 5,
    .timeout    = HZ
};

static struct i2c_adapter hydra_adap = {
    .owner      = THIS_MODULE,
    .name       = "Hydra i2c",
    .algo_data  = &hydra_bit_data,
};

static DEFINE_PCI_DEVICE_TABLE(hydra_ids) = {
    { PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
    { 0, }
};

MODULE_DEVICE_TABLE (pci, hydra_ids);

static int __devinit hydra_probe(struct pci_dev *dev,
                 const struct pci_device_id *id)
{
    unsigned long base = pci_resource_start(dev, 0);
    int res;

    if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
                hydra_adap.name))
        return -EBUSY;

    hydra_bit_data.data = pci_ioremap_bar(dev, 0);
    if (hydra_bit_data.data == NULL) {
        release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
        return -ENODEV;
    }

    pdregw(hydra_bit_data.data, 0);     /* clear SCLK_OE and SDAT_OE */
    hydra_adap.dev.parent = &dev->dev;
    res = i2c_bit_add_bus(&hydra_adap);
    if (res < 0) {
        iounmap(hydra_bit_data.data);
        release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
        return res;
    }
    return 0;
}

static void __devexit hydra_remove(struct pci_dev *dev)
{
    pdregw(hydra_bit_data.data, 0);     /* clear SCLK_OE and SDAT_OE */
    i2c_del_adapter(&hydra_adap);
    iounmap(hydra_bit_data.data);
    release_mem_region(pci_resource_start(dev, 0)+
               offsetof(struct Hydra, CachePD), 4);
}


static struct pci_driver hydra_driver = {
    .name       = "hydra_smbus",
    .id_table   = hydra_ids,
    .probe      = hydra_probe,
    .remove     = __devexit_p(hydra_remove),
};

module_pci_driver(hydra_driver);

MODULE_AUTHOR("Geert Uytterhoeven <[email protected]>");
MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
MODULE_LICENSE("GPL");