// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * 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 <c.pascoe@itee.uq.edu.au>
 */

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

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/io.h>

MODULE_DESCRIPTION("driver for cx2388x VP3054 design");
MODULE_AUTHOR("Chris Pascoe <c.pascoe@itee.uq.edu.au>");
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_obj(*vp3054_i2c);
        if (!vp3054_i2c)
                return -ENOMEM;
        dev->vp3054 = vp3054_i2c;

        vp3054_i2c->algo = vp3054_i2c_algo_template;

        vp3054_i2c->adap.dev.parent = &dev->pci->dev;
        strscpy(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 (rc != 0) {
                pr_err("vp3054_i2c register FAILED\n");

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

        return rc;
}
EXPORT_SYMBOL(vp3054_i2c_probe);

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

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

        i2c_del_adapter(&vp3054_i2c->adap);
        kfree(vp3054_i2c);
}
EXPORT_SYMBOL(vp3054_i2c_remove);