// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2015-2022, NVIDIA CORPORATION.  All rights reserved.

#include <linux/slab.h>

#include <media/tegra_camera_dev_mfi.h>

static LIST_HEAD(cmfidev_list);
static DEFINE_MUTEX(cmfidev_mutex);

static int tegra_camera_dev_mfi_init(void)
{
	INIT_LIST_HEAD(&cmfidev_list);

	return 0;
}

void tegra_camera_dev_mfi_cb(void *stub)
{
	u32 idx = 0;
	struct camera_mfi_dev *itr = NULL;
	int err = 0;
	mutex_lock(&cmfidev_mutex);
	list_for_each_entry(itr, &cmfidev_list, list) {
		if (itr->regmap) {
			/* MFI driver has to delay the focuser writes by one
			 * frame, which is required to get sync in focus
			 * position and sharpness.
			 * So write previous frame focuser settings in current
			 * frame's callback, and then save current frame focuser
			 * writes for next callback.
			 */
			for (idx = 0; idx < itr->prev_num_used; idx++) {
				err = regmap_write(itr->regmap,
						itr->prev_reg[idx].addr,
						itr->prev_reg[idx].val);
				if (err)
					pr_err("%s: [%s] regmap_write failed\n",
						__func__, itr->name);
			}
			/* Consume current settings, which would be programmed
			 * in next frame callback.
			 */
			for (idx = 0; idx < itr->num_used; idx++) {
				itr->prev_reg[idx].addr = itr->reg[idx].addr;
				itr->prev_reg[idx].val = itr->reg[idx].val;
			}
			itr->prev_num_used = itr->num_used;
		} else if (itr->i2c_client) {
			for (idx = 0; idx < itr->num_used; idx++) {
				err = i2c_transfer(itr->i2c_client->adapter,
						&itr->msg[idx].msg, 1);
				if (err != 1)
					pr_err("%s: [%s] i2c_transfer failed\n",
						__func__, itr->name);
			}
		} else {
			pr_err("%s [%s] Unknown device mechanism\n",
				__func__, itr->name);
		}
		itr->num_used = 0;
	}
	mutex_unlock(&cmfidev_mutex);
}
EXPORT_SYMBOL(tegra_camera_dev_mfi_cb);

int tegra_camera_dev_mfi_wr_add_i2c(
	struct camera_mfi_dev *cmfidev,
	struct i2c_msg *msg, int num)
{
	int err = -ENODEV;
	int i = 0;
	struct camera_mfi_dev *itr = NULL;

	if (!strcmp(cmfidev->name, "")) {
		err = -EINVAL;
		goto cmfi_wr_add_i2c_end;
	}

	mutex_lock(&cmfidev_mutex);
	list_for_each_entry(itr, &cmfidev_list, list) {
		if (!strcmp(itr->name, cmfidev->name)) {
			if (itr->num_used == CAMERA_REGCACHE_MAX)
				err = -ENOSPC;
			else {
				for (i = 0; i < num; i++) {
					itr->msg[itr->num_used].msg = msg[i];
					memcpy(itr->msg[itr->num_used].buf,
								msg[i].buf,
								msg[i].len);
					itr->msg[itr->num_used].msg.buf =
						itr->msg[itr->num_used].buf;
					itr->num_used++;
				}
				err = 0;
			}
		}
	}
	mutex_unlock(&cmfidev_mutex);

cmfi_wr_add_i2c_end:
	return err;
}
EXPORT_SYMBOL(tegra_camera_dev_mfi_wr_add_i2c);

int tegra_camera_dev_mfi_wr_add(
	struct camera_mfi_dev *cmfidev,
	u32 offset, u32 val)
{
	int err = -ENODEV;
	struct camera_mfi_dev *itr = NULL;

	if (!strcmp(cmfidev->name, "")) {
		err = -EINVAL;
		goto cmfi_wr_add_end;
	}

	mutex_lock(&cmfidev_mutex);
	list_for_each_entry(itr, &cmfidev_list, list) {
		if (!strcmp(itr->name, cmfidev->name)) {
			if (itr->num_used == CAMERA_REGCACHE_MAX) {
				err = -ENOSPC;
			} else {
				itr->reg[itr->num_used].addr = offset;
				itr->reg[itr->num_used].val = val;
				itr->num_used++;
				err = 0;
			}
		}
	}
	mutex_unlock(&cmfidev_mutex);

cmfi_wr_add_end:
	return err;
}
EXPORT_SYMBOL(tegra_camera_dev_mfi_wr_add);

int tegra_camera_dev_mfi_clear(struct camera_mfi_dev *cmfidev)
{
	int err = -ENODEV;
	struct camera_mfi_dev *itr = NULL;

	if (cmfidev == NULL) {
		err = -EINVAL;
		goto cmfidev_clear_end;
	}

	if (!strcmp(cmfidev->name, "")) {
		err = -EINVAL;
		goto cmfidev_clear_end;
	}

	mutex_lock(&cmfidev_mutex);
	list_for_each_entry(itr, &cmfidev_list, list) {
		if (!strcmp(itr->name, cmfidev->name)) {
			if (itr->num_used > 0)
				pr_info("%s [%s] force clear Q pending writes\n",
						__func__, itr->name);
			itr->num_used = 0;
			err = 0;
		}
	}
	mutex_unlock(&cmfidev_mutex);

cmfidev_clear_end:
	return err;
}
EXPORT_SYMBOL(tegra_camera_dev_mfi_clear);

int tegra_camera_dev_mfi_add_i2cclient(
	struct camera_mfi_dev **cmfidev,
	u8 *name,
	struct i2c_client *i2c_client)
{
	int err = 0;
	struct camera_mfi_dev *itr = NULL;
	struct camera_mfi_dev *new_cmfidev = NULL;

	if (name == NULL || !strcmp(name, ""))
		return -EINVAL;

	mutex_lock(&cmfidev_mutex);
	list_for_each_entry(itr, &cmfidev_list, list) {
		if (!strcmp(itr->name, name)) {
			err = -EEXIST;
			goto cmfidev_add_i2c_unlock;
		}
	}
	if (!err) {
		new_cmfidev =
			kzalloc(sizeof(struct camera_mfi_dev), GFP_KERNEL);
		if (!new_cmfidev) {
			pr_err("%s memory low!\n", __func__);
			err = -ENOMEM;
			goto cmfidev_add_i2c_unlock;
		}
		memset(new_cmfidev, 0, sizeof(struct camera_mfi_dev));
		strncpy(new_cmfidev->name, name, sizeof(new_cmfidev->name)-1);
		INIT_LIST_HEAD(&new_cmfidev->list);
		new_cmfidev->i2c_client = i2c_client;
		new_cmfidev->num_used = 0;
		list_add(&new_cmfidev->list, &cmfidev_list);
	}

	*cmfidev = new_cmfidev;

cmfidev_add_i2c_unlock:
	mutex_unlock(&cmfidev_mutex);

	return err;
}
EXPORT_SYMBOL(tegra_camera_dev_mfi_add_i2cclient);

int tegra_camera_dev_mfi_add_regmap(
	struct camera_mfi_dev **cmfidev,
	u8 *name,
	struct regmap *regmap)
{
	int err = 0;
	struct camera_mfi_dev *itr = NULL;
	struct camera_mfi_dev *new_cmfidev = NULL;

	if (name == NULL || !strcmp(name, ""))
		return -EINVAL;

	mutex_lock(&cmfidev_mutex);
	list_for_each_entry(itr, &cmfidev_list, list) {
		if (!strcmp(itr->name, name)) {
			err = -EEXIST;
			goto cmfidev_add_regmap_unlock;
		}
	}
	if (!err) {
		new_cmfidev =
			kzalloc(sizeof(struct camera_mfi_dev), GFP_KERNEL);
		if (!new_cmfidev) {
			pr_err("%s memory low!\n", __func__);
			err = -ENOMEM;
			goto cmfidev_add_regmap_unlock;
		}
		memset(new_cmfidev, 0, sizeof(struct camera_mfi_dev));
		strncpy(new_cmfidev->name, name, sizeof(new_cmfidev->name)-1);
		INIT_LIST_HEAD(&new_cmfidev->list);
		new_cmfidev->regmap = regmap;
		new_cmfidev->num_used = 0;
		new_cmfidev->prev_num_used = 0;
		if (list_empty(&cmfidev_list))
			tegra_camera_dev_mfi_init();
		list_add(&new_cmfidev->list, &cmfidev_list);
	}

	*cmfidev = new_cmfidev;

cmfidev_add_regmap_unlock:
	mutex_unlock(&cmfidev_mutex);

	return err;
}
EXPORT_SYMBOL(tegra_camera_dev_mfi_add_regmap);
MODULE_LICENSE("GPL");