// SPDX-License-Identifier: GPL-2.0-only

/*
 * Hauppauge HD PVR USB driver
 *
 * Copyright (C) 2008      Janne Grunau (j@jannau.net)
 *
 * IR device registration code is
 * Copyright (C) 2010   Andy Walls <awalls@md.metrocast.net>
 */

#if IS_ENABLED(CONFIG_I2C)

#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/export.h>

#include "hdpvr.h"

#define CTRL_READ_REQUEST       0xb8
#define CTRL_WRITE_REQUEST      0x38

#define REQTYPE_I2C_READ        0xb1
#define REQTYPE_I2C_WRITE       0xb0
#define REQTYPE_I2C_WRITE_STATT 0xd0

#define Z8F0811_IR_TX_I2C_ADDR  0x70
#define Z8F0811_IR_RX_I2C_ADDR  0x71


struct i2c_client *hdpvr_register_ir_i2c(struct hdpvr_device *dev)
{
        struct IR_i2c_init_data *init_data = &dev->ir_i2c_init_data;
        struct i2c_board_info info = {
                I2C_BOARD_INFO("ir_z8f0811_hdpvr", Z8F0811_IR_RX_I2C_ADDR),
        };

        /* Our default information for ir-kbd-i2c.c to use */
        init_data->ir_codes = RC_MAP_HAUPPAUGE;
        init_data->internal_get_key_func = IR_KBD_GET_KEY_HAUP_XVR;
        init_data->type = RC_PROTO_BIT_RC5 | RC_PROTO_BIT_RC6_MCE |
                          RC_PROTO_BIT_RC6_6A_32;
        init_data->name = "HD-PVR";
        init_data->polling_interval = 405; /* ms, duplicated from Windows */
        info.platform_data = init_data;

        return i2c_new_device(&dev->i2c_adapter, &info);
}

static int hdpvr_i2c_read(struct hdpvr_device *dev, int bus,
                          unsigned char addr, char *wdata, int wlen,
                          char *data, int len)
{
        int ret;

        if ((len > sizeof(dev->i2c_buf)) || (wlen > sizeof(dev->i2c_buf)))
                return -EINVAL;

        if (wlen) {
                memcpy(dev->i2c_buf, wdata, wlen);
                ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
                                      REQTYPE_I2C_WRITE, CTRL_WRITE_REQUEST,
                                      (bus << 8) | addr, 0, dev->i2c_buf,
                                      wlen, 1000);
                if (ret < 0)
                        return ret;
        }

        ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
                              REQTYPE_I2C_READ, CTRL_READ_REQUEST,
                              (bus << 8) | addr, 0, dev->i2c_buf, len, 1000);

        if (ret == len) {
                memcpy(data, dev->i2c_buf, len);
                ret = 0;
        } else if (ret >= 0)
                ret = -EIO;

        return ret;
}

static int hdpvr_i2c_write(struct hdpvr_device *dev, int bus,
                           unsigned char addr, char *data, int len)
{
        int ret;

        if (len > sizeof(dev->i2c_buf))
                return -EINVAL;

        memcpy(dev->i2c_buf, data, len);
        ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
                              REQTYPE_I2C_WRITE, CTRL_WRITE_REQUEST,
                              (bus << 8) | addr, 0, dev->i2c_buf, len, 1000);

        if (ret < 0)
                return ret;

        ret = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
                              REQTYPE_I2C_WRITE_STATT, CTRL_READ_REQUEST,
                              0, 0, dev->i2c_buf, 2, 1000);

        if ((ret == 2) && (dev->i2c_buf[1] == (len - 1)))
                ret = 0;
        else if (ret >= 0)
                ret = -EIO;

        return ret;
}

static int hdpvr_transfer(struct i2c_adapter *i2c_adapter, struct i2c_msg *msgs,
                          int num)
{
        struct hdpvr_device *dev = i2c_get_adapdata(i2c_adapter);
        int retval = 0, addr;

        mutex_lock(&dev->i2c_mutex);

        addr = msgs[0].addr << 1;

        if (num == 1) {
                if (msgs[0].flags & I2C_M_RD)
                        retval = hdpvr_i2c_read(dev, 1, addr, NULL, 0,
                                                msgs[0].buf, msgs[0].len);
                else
                        retval = hdpvr_i2c_write(dev, 1, addr, msgs[0].buf,
                                                 msgs[0].len);
        } else if (num == 2) {
                if (msgs[0].addr != msgs[1].addr) {
                        v4l2_warn(&dev->v4l2_dev, "refusing 2-phase i2c xfer with conflicting target addresses\n");
                        retval = -EINVAL;
                        goto out;
                }

                if ((msgs[0].flags & I2C_M_RD) || !(msgs[1].flags & I2C_M_RD)) {
                        v4l2_warn(&dev->v4l2_dev, "refusing complex xfer with r0=%d, r1=%d\n",
                                  msgs[0].flags & I2C_M_RD,
                                  msgs[1].flags & I2C_M_RD);
                        retval = -EINVAL;
                        goto out;
                }

                /*
                 * Write followed by atomic read is the only complex xfer that
                 * we actually support here.
                 */
                retval = hdpvr_i2c_read(dev, 1, addr, msgs[0].buf, msgs[0].len,
                                        msgs[1].buf, msgs[1].len);
        } else {
                v4l2_warn(&dev->v4l2_dev, "refusing %d-phase i2c xfer\n", num);
        }

out:
        mutex_unlock(&dev->i2c_mutex);

        return retval ? retval : num;
}

static u32 hdpvr_functionality(struct i2c_adapter *adapter)
{
        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}

static const struct i2c_algorithm hdpvr_algo = {
        .master_xfer   = hdpvr_transfer,
        .functionality = hdpvr_functionality,
};

static const struct i2c_adapter hdpvr_i2c_adapter_template = {
        .name   = "Hauppauge HD PVR I2C",
        .owner  = THIS_MODULE,
        .algo   = &hdpvr_algo,
};

static int hdpvr_activate_ir(struct hdpvr_device *dev)
{
        char buffer[2];

        mutex_lock(&dev->i2c_mutex);

        hdpvr_i2c_read(dev, 0, 0x54, NULL, 0, buffer, 1);

        buffer[0] = 0;
        buffer[1] = 0x8;
        hdpvr_i2c_write(dev, 1, 0x54, buffer, 2);

        buffer[1] = 0x18;
        hdpvr_i2c_write(dev, 1, 0x54, buffer, 2);

        mutex_unlock(&dev->i2c_mutex);

        return 0;
}

int hdpvr_register_i2c_adapter(struct hdpvr_device *dev)
{
        int retval = -ENOMEM;

        hdpvr_activate_ir(dev);

        dev->i2c_adapter = hdpvr_i2c_adapter_template;
        dev->i2c_adapter.dev.parent = &dev->udev->dev;

        i2c_set_adapdata(&dev->i2c_adapter, dev);

        retval = i2c_add_adapter(&dev->i2c_adapter);

        return retval;
}

#endif