// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Driver for the NXP SAA7164 PCIe bridge
 *
 *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/io.h>

#include "saa7164.h"

static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
        struct saa7164_i2c *bus = i2c_adap->algo_data;
        struct saa7164_dev *dev = bus->dev;
        int i, retval = 0;

        dprintk(DBGLVL_I2C, "%s(num = %d)\n", __func__, num);

        for (i = 0 ; i < num; i++) {
                dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
                        __func__, num, msgs[i].addr, msgs[i].len);
                if (msgs[i].flags & I2C_M_RD) {
                        retval = saa7164_api_i2c_read(bus,
                                msgs[i].addr,
                                0 /* reglen */,
                                NULL /* reg */, msgs[i].len, msgs[i].buf);
                } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
                           msgs[i].addr == msgs[i + 1].addr) {
                        /* write then read from same address */

                        retval = saa7164_api_i2c_read(bus, msgs[i].addr,
                                msgs[i].len, msgs[i].buf,
                                msgs[i+1].len, msgs[i+1].buf
                                );

                        i++;

                        if (retval < 0)
                                goto err;
                } else {
                        /* write */
                        retval = saa7164_api_i2c_write(bus, msgs[i].addr,
                                msgs[i].len, msgs[i].buf);
                }
                if (retval < 0)
                        goto err;
        }
        return num;

err:
        return retval;
}

static u32 saa7164_functionality(struct i2c_adapter *adap)
{
        return I2C_FUNC_I2C;
}

static const struct i2c_algorithm saa7164_i2c_algo_template = {
        .master_xfer    = i2c_xfer,
        .functionality  = saa7164_functionality,
};

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

static const struct i2c_adapter saa7164_i2c_adap_template = {
        .name              = "saa7164",
        .owner             = THIS_MODULE,
        .algo              = &saa7164_i2c_algo_template,
};

static const struct i2c_client saa7164_i2c_client_template = {
        .name   = "saa7164 internal",
};

int saa7164_i2c_register(struct saa7164_i2c *bus)
{
        struct saa7164_dev *dev = bus->dev;

        dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);

        bus->i2c_adap = saa7164_i2c_adap_template;
        bus->i2c_client = saa7164_i2c_client_template;

        bus->i2c_adap.dev.parent = &dev->pci->dev;

        strscpy(bus->i2c_adap.name, bus->dev->name,
                sizeof(bus->i2c_adap.name));

        bus->i2c_adap.algo_data = bus;
        i2c_set_adapdata(&bus->i2c_adap, bus);
        i2c_add_adapter(&bus->i2c_adap);

        bus->i2c_client.adapter = &bus->i2c_adap;

        if (0 != bus->i2c_rc)
                printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
                        dev->name, bus->nr);

        return bus->i2c_rc;
}

int saa7164_i2c_unregister(struct saa7164_i2c *bus)
{
        i2c_del_adapter(&bus->i2c_adap);
        return 0;
}