// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "i2c.h"

#include <lib/sync/completion.h>
#include <threads.h>
#include <zircon/types.h>

#include <memory>

#include <ddk/binding.h>
#include <ddk/debug.h>
#include <ddk/device.h>
#include <ddk/metadata.h>
#include <ddk/metadata/i2c.h>
#include <fbl/alloc_checker.h>
#include <fbl/mutex.h>

#include "i2c-child.h"

namespace i2c {

void I2cDevice::DdkUnbindNew(ddk::UnbindTxn txn) { txn.Reply(); }

void I2cDevice::DdkRelease() { delete this; }

zx_status_t I2cDevice::Create(void* ctx, zx_device_t* parent) {
  i2c_impl_protocol_t i2c;
  auto status = device_get_protocol(parent, ZX_PROTOCOL_I2C_IMPL, &i2c);
  if (status != ZX_OK) {
    return status;
  }

  fbl::AllocChecker ac;
  std::unique_ptr<I2cDevice> device(new (&ac) I2cDevice(parent, &i2c));
  if (!ac.check()) {
    return ZX_ERR_NO_MEMORY;
  }

  status = device->Init(&i2c);
  if (status != ZX_OK) {
    return status;
  }

  status = device->DdkAdd("i2c");
  if (status != ZX_OK) {
    return status;
  }

  device->AddChildren();

  __UNUSED auto* dummy = device.release();

  return ZX_OK;
}

zx_status_t I2cDevice::Init(ddk::I2cImplProtocolClient i2c) {
  uint32_t bus_count = i2c.GetBusCount();
  if (!bus_count) {
    return ZX_ERR_NOT_SUPPORTED;
  }

  fbl::AllocChecker ac;
  i2c_buses_.reserve(bus_count, &ac);
  if (!ac.check()) {
    return ZX_ERR_NO_MEMORY;
  }

  for (uint32_t i = 0; i < bus_count; i++) {
    auto i2c_bus = fbl::MakeRefCountedChecked<I2cBus>(&ac, i2c, i);
    if (!ac.check()) {
      return ZX_ERR_NO_MEMORY;
    }

    auto status = i2c_bus->Start();
    if (status != ZX_OK) {
      return status;
    }

    i2c_buses_.push_back(std::move(i2c_bus));
  }

  return ZX_OK;
}

void I2cDevice::AddChildren() {
  size_t metadata_size;
  auto status = device_get_metadata_size(zxdev(), DEVICE_METADATA_I2C_CHANNELS, &metadata_size);
  if (status != ZX_OK) {
    zxlogf(ERROR, "%s: device_get_metadata_size failed %d", __func__, status);
    return;
  }
  auto channel_count = metadata_size / sizeof(i2c_channel_t);

  fbl::AllocChecker ac;
  std::unique_ptr<i2c_channel_t[]> channels(new (&ac) i2c_channel_t[channel_count]);
  if (!ac.check()) {
    zxlogf(ERROR, "%s: out of memory", __func__);
    return;
  }

  size_t actual;
  status = device_get_metadata(zxdev(), DEVICE_METADATA_I2C_CHANNELS, channels.get(), metadata_size,
                               &actual);
  if (status != ZX_OK || actual != metadata_size) {
    zxlogf(ERROR, "%s: device_get_metadata failed %d", __func__, status);
    return;
  }

  for (uint32_t i = 0; i < channel_count; i++) {
    const auto& channel = channels[i];
    const auto bus_id = channel.bus_id;
    const auto address = channel.address;
    const auto vid = channel.vid;
    const auto pid = channel.pid;
    const auto did = channel.did;

    if (bus_id >= i2c_buses_.size()) {
      zxlogf(ERROR, "%s: bus_id %u out of range", __func__, bus_id);
      return;
    }

    fbl::AllocChecker ac;
    std::unique_ptr<I2cChild> dev(new (&ac) I2cChild(zxdev(), i2c_buses_[bus_id], channel.address));
    if (!ac.check()) {
      zxlogf(ERROR, "%s: out of memory", __func__);
      return;
    }

    char name[20];
    snprintf(name, sizeof(name), "i2c-%u-%u", bus_id, address);

    if (vid || pid || did) {
      zx_device_prop_t props[] = {
          {BIND_I2C_BUS_ID, 0, bus_id},    {BIND_I2C_ADDRESS, 0, address},
          {BIND_PLATFORM_DEV_VID, 0, vid}, {BIND_PLATFORM_DEV_PID, 0, pid},
          {BIND_PLATFORM_DEV_DID, 0, did},
      };

      status = dev->DdkAdd(name, 0, props, countof(props));
    } else {
      zx_device_prop_t props[] = {
          {BIND_I2C_BUS_ID, 0, bus_id},
          {BIND_I2C_ADDRESS, 0, address},
      };

      status = dev->DdkAdd(name, 0, props, countof(props));
    }

    if (status != ZX_OK) {
      zxlogf(ERROR, "%s: DdkAdd failed %d", __func__, status);
      return;
    }

    // dev is now owned by devmgr.
    __UNUSED auto ptr = dev.release();
  }
}

static constexpr zx_driver_ops_t driver_ops = []() {
  zx_driver_ops_t ops = {};
  ops.version = DRIVER_OPS_VERSION;
  ops.bind = I2cDevice::Create;
  return ops;
}();

}  // namespace i2c

ZIRCON_DRIVER_BEGIN(i2c, i2c::driver_ops, "zircon", "0.1", 1)
BI_MATCH_IF(EQ, BIND_PROTOCOL, ZX_PROTOCOL_I2C_IMPL), ZIRCON_DRIVER_END(i2c)