cx88-vp3054-i2c.c

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/*

    cx88-vp3054-i2c.c  --  support for the secondary I2C bus of the
               DNTV Live! DVB-T Pro (VP-3054), wired as:
               GPIO[0] -> SCL, GPIO[1] -> SDA

    (c) 2005 Chris Pascoe <[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/module.h>
#include <linux/slab.h>
#include <linux/init.h>

#include <asm/io.h>

#include "cx88.h"
#include "cx88-vp3054-i2c.h"

MODULE_DESCRIPTION("driver for cx2388x VP3054 design");
MODULE_AUTHOR("Chris Pascoe <[email protected]>");
MODULE_LICENSE("GPL");

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

static void vp3054_bit_setscl(void *data, int state)
{
    struct cx8802_dev *dev = data;
    struct cx88_core *core = dev->core;
    struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;

    if (state) {
        vp3054_i2c->state |=  0x0001;   /* SCL high */
        vp3054_i2c->state &= ~0x0100;   /* external pullup */
    } else {
        vp3054_i2c->state &= ~0x0001;   /* SCL low */
        vp3054_i2c->state |=  0x0100;   /* drive pin */
    }
    cx_write(MO_GP0_IO, 0x010000 | vp3054_i2c->state);
    cx_read(MO_GP0_IO);
}

static void vp3054_bit_setsda(void *data, int state)
{
    struct cx8802_dev *dev = data;
    struct cx88_core *core = dev->core;
    struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;

    if (state) {
        vp3054_i2c->state |=  0x0002;   /* SDA high */
        vp3054_i2c->state &= ~0x0200;   /* tristate pin */
    } else {
        vp3054_i2c->state &= ~0x0002;   /* SDA low */
        vp3054_i2c->state |=  0x0200;   /* drive pin */
    }
    cx_write(MO_GP0_IO, 0x020000 | vp3054_i2c->state);
    cx_read(MO_GP0_IO);
}

static int vp3054_bit_getscl(void *data)
{
    struct cx8802_dev *dev = data;
    struct cx88_core *core = dev->core;
    u32 state;

    state = cx_read(MO_GP0_IO);
    return (state & 0x01) ? 1 : 0;
}

static int vp3054_bit_getsda(void *data)
{
    struct cx8802_dev *dev = data;
    struct cx88_core *core = dev->core;
    u32 state;

    state = cx_read(MO_GP0_IO);
    return (state & 0x02) ? 1 : 0;
}

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

static const struct i2c_algo_bit_data vp3054_i2c_algo_template = {
    .setsda  = vp3054_bit_setsda,
    .setscl  = vp3054_bit_setscl,
    .getsda  = vp3054_bit_getsda,
    .getscl  = vp3054_bit_getscl,
    .udelay  = 16,
    .timeout = 200,
};

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

int vp3054_i2c_probe(struct cx8802_dev *dev)
{
    struct cx88_core *core = dev->core;
    struct vp3054_i2c_state *vp3054_i2c;
    int rc;

    if (core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
        return 0;

    vp3054_i2c = kzalloc(sizeof(*vp3054_i2c), GFP_KERNEL);
    if (vp3054_i2c == NULL)
        return -ENOMEM;
    dev->vp3054 = vp3054_i2c;

    memcpy(&vp3054_i2c->algo, &vp3054_i2c_algo_template,
           sizeof(vp3054_i2c->algo));

    vp3054_i2c->adap.dev.parent = &dev->pci->dev;
    strlcpy(vp3054_i2c->adap.name, core->name,
        sizeof(vp3054_i2c->adap.name));
    vp3054_i2c->adap.owner = THIS_MODULE;
    vp3054_i2c->algo.data = dev;
    i2c_set_adapdata(&vp3054_i2c->adap, dev);
    vp3054_i2c->adap.algo_data = &vp3054_i2c->algo;

    vp3054_bit_setscl(dev,1);
    vp3054_bit_setsda(dev,1);

    rc = i2c_bit_add_bus(&vp3054_i2c->adap);
    if (0 != rc) {
        printk("%s: vp3054_i2c register FAILED\n", core->name);

        kfree(dev->vp3054);
        dev->vp3054 = NULL;
    }

    return rc;
}

void vp3054_i2c_remove(struct cx8802_dev *dev)
{
    struct vp3054_i2c_state *vp3054_i2c = dev->vp3054;

    if (vp3054_i2c == NULL ||
        dev->core->boardnr != CX88_BOARD_DNTV_LIVE_DVB_T_PRO)
        return;

    i2c_del_adapter(&vp3054_i2c->adap);
    kfree(vp3054_i2c);
}

EXPORT_SYMBOL(vp3054_i2c_probe);
EXPORT_SYMBOL(vp3054_i2c_remove);