/*
 * Copyright (C) 2018 Spreadtrum Communications Inc.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/cdev.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/of_device.h>

#include "../include/sipc.h"
#include "spool.h"

#define SLOG_NR_BASE_NUM		MKDEV(156, 0)

struct spool_device;

struct spool_device {
	struct spool_init_data	*init;
	int			major;
	int			minor;
	struct cdev		cdev;
	struct platform_device	*plt_dev;

	struct device		*sys_dev;	/* Device object in sysfs */
};

struct spool_sblock {
	u8			dst;
	u8			channel;
	bool			is_hold;
	struct sblock	hold;
};

static struct class	*spool_class;

static int spool_open(struct inode *inode, struct file *filp)
{
	struct spool_device *spool;
	struct spool_sblock *sblock;
	int ret;

	spool = container_of(inode->i_cdev, struct spool_device, cdev);
	ret = sblock_query(spool->init->dst, spool->init->channel);
	if (ret)
		return ret;
	sblock = kmalloc(sizeof(struct spool_sblock), GFP_KERNEL);
	if (!sblock)
		return -ENOMEM;
	filp->private_data = sblock;

	sblock->dst = spool->init->dst;
	sblock->channel = spool->init->channel;
	sblock->is_hold = 0;

	return 0;
}

static int spool_release(struct inode *inode, struct file *filp)
{
	struct spool_sblock *sblock = filp->private_data;

	if (sblock->is_hold) {
		if (sblock_release(sblock->dst, sblock->channel, &sblock->hold))
			pr_debug("failed to release block!\n");
	}
	kfree(sblock);

	return 0;
}

static ssize_t spool_read(struct file *filp,
			  char __user *buf, size_t count, loff_t *ppos)
{
	struct spool_sblock *sblock = filp->private_data;
	int timeout = -1;
	int ret = 0;
	int rdsize = 0;
	struct sblock blk = {0};

	if (filp->f_flags & O_NONBLOCK)
		timeout = 0;

	if (sblock->is_hold) {
		if (count < sblock->hold.length - *ppos) {
			rdsize = count;
		} else {
			rdsize = sblock->hold.length - *ppos;
			sblock->is_hold = 0;
		}
		blk = sblock->hold;
	} else{
		*ppos = 0;
		ret = sblock_receive(sblock->dst,
				sblock->channel, &blk, timeout);
		if (ret < 0) {
			pr_debug("%s: failed to receive block!\n", __func__);
			return ret;
		}
		if (blk.length <= count)
			rdsize = blk.length;
		else {
			rdsize = count;
			sblock->is_hold = 1;
			sblock->hold = blk;
		}
	}

	if (unalign_copy_to_user(buf, blk.addr + *ppos, rdsize)) {
		pr_err("%s: failed to copy to user!\n", __func__);
		sblock->is_hold = 0;
		*ppos = 0;
		ret = -EFAULT;
	} else {
		ret = rdsize;
		*ppos += rdsize;
	}

	if (sblock->is_hold == 0) {
		if (sblock_release(sblock->dst, sblock->channel, &blk))
			pr_err("%s: failed to release block!\n", __func__);
	}

	return ret;
}

static ssize_t spool_write(struct file *filp,
			   const char __user *buf, size_t count, loff_t *ppos)
{
	struct spool_sblock *sblock = filp->private_data;
	int timeout = -1;
	int ret = 0;
	int wrsize = 0;
	int pos = 0;
	struct sblock blk = {0};
	size_t len = count;

	if (filp->f_flags & O_NONBLOCK)
		timeout = 0;

	do {
		ret = sblock_get(sblock->dst, sblock->channel, &blk, timeout);
		if (ret < 0) {
			pr_info("%s: failed to get block!\n", __func__);
			return ret;
		}

		wrsize = (blk.length > len ? len : blk.length);
		if (unalign_copy_from_user(blk.addr, buf + pos, wrsize)) {
			pr_info("%s: failed to copy from user!\n", __func__);
			ret = -EFAULT;
		} else {
			blk.length = wrsize;
			len -= wrsize;
			pos += wrsize;
		}

		if (sblock_send(sblock->dst, sblock->channel, &blk))
			pr_debug("%s: failed to send block!", __func__);
	} while (len > 0 && ret == 0);

	return count - len;
}

static unsigned int spool_poll(struct file *filp, poll_table *wait)
{
	struct spool_sblock *sblock = filp->private_data;

	return sblock_poll_wait(sblock->dst, sblock->channel, filp, wait);
}

static long spool_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	return 0;
}

static const struct file_operations spool_fops = {
	.open		= spool_open,
	.release	= spool_release,
	.read		= spool_read,
	.write		= spool_write,
	.poll		= spool_poll,
	.unlocked_ioctl	= spool_ioctl,
	.owner		= THIS_MODULE,
	.llseek		= default_llseek,
};

#ifdef SPRD_PCIE_USE_DTS
static int spool_parse_dt(struct spool_init_data **init, struct device *dev,
			  struct device_node *np, dev_t *dev_no)
{
	struct spool_init_data *pdata = NULL;
	int ret;
	u32 data;

	pdata = devm_kzalloc(dev, sizeof(struct spool_init_data), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;

	ret = of_property_read_string(np, "sprd,name",
				      (const char **)&pdata->name);
	if (ret)
		goto error;

	if (!strcmp(pdata->name, "slog_nr"))
		*dev_no = SLOG_NR_BASE_NUM;

	ret = of_property_read_u32(np, "sprd,dst", (u32 *)&data);
	if (ret)
		goto error;
	pdata->dst = (u8)data;

	ret = of_property_read_u32(np, "sprd,channel", (u32 *)&data);
	if (ret)
		goto error;
	pdata->channel = (u8)data;

	ret = of_property_read_u32(np, "sprd,preconfigured", (u32 *)&data);
	if (!ret)
		pdata->pre_cfg = (int)data;

	ret = of_property_read_u32(np, "sprd,tx-blksize",
				   (u32 *)&pdata->txblocksize);
	if (ret)
		goto error;
	ret = of_property_read_u32(np, "sprd,tx-blknum",
				   (u32 *)&pdata->txblocknum);
	if (ret)
		goto error;
	ret = of_property_read_u32(np, "sprd,rx-blksize",
				   (u32 *)&pdata->rxblocksize);
	if (ret)
		goto error;
	ret = of_property_read_u32(np, "sprd,rx-blknum",
				   (u32 *)&pdata->rxblocknum);
	if (ret)
		goto error;

	if (!of_property_read_u32(np, "sprd,nodev", (u32 *)&data))
		pdata->nodev = (u8)data;

	*init = pdata;
	return ret;
error:
	devm_kfree(dev, pdata);
	*init = NULL;
	return ret;
}
#else
static int spool_parse_dt(struct spool_init_data **init, struct device *dev,
			  struct device_node *np, dev_t *dev_no)
{
	struct spool_init_data *pdata = NULL;

	pdata = devm_kzalloc(dev, sizeof(struct spool_init_data), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;
        pdata->name =  "slog_nr";
	if (!strcmp(pdata->name, "slog_nr"))
		*dev_no = SLOG_NR_BASE_NUM;
	pdata->dst = 1;
	pdata->channel = 5;
        pdata->txblocksize = 0;
	pdata->txblocknum = 0;
	pdata->rxblocksize = 0x10000;
        pdata->rxblocknum = 32;
	*init = pdata;

	return 0;
}
#endif


static ssize_t base_addr_show(struct device *dev,
			       struct device_attribute *attr,
			       char *buf)
{
	struct spool_device *spool = (struct spool_device *)
		dev_get_drvdata(dev);
	struct spool_init_data *init = spool->init;
	uint32_t addr;
	int ret;

	ret = sblock_get_smem_cp_addr(init->dst, init->channel,
				      &addr);
	if (ret < 0)
		return ret;

	return snprintf(buf, PAGE_SIZE, "%u %u 0x%08X %d %u %u %u %u\n",
			(unsigned int)init->dst,
			(unsigned int)init->channel,
			addr,
			init->pre_cfg,
			(unsigned int)init->txblocknum,
			(unsigned int)init->txblocksize,
			(unsigned int)init->rxblocknum,
			(unsigned int)init->rxblocksize);
}

static DEVICE_ATTR(base_addr, 0440,
		    base_addr_show, NULL);

static int create_spool(struct platform_device *pdev,
			struct spool_init_data *init,
			struct spool_device **out, dev_t dev_no)
{
	int rval;
	struct spool_device *spool;
	//dev_t dev_no;
	char sp_name[16];

	snprintf(sp_name, sizeof(sp_name), "spool-%u-%u",
		 (unsigned int)init->dst,
		 (unsigned int)init->channel);
	//rval = alloc_chrdev_region(&dev_no, 0, 1, sp_name);
	rval = register_chrdev_region(dev_no, 1, sp_name);
	if (rval)
		return rval;

	if (init->pre_cfg)
		rval = sblock_pcfg_create(init->dst,
					  init->channel,
					  init->txblocknum,
					  init->txblocksize,
					  init->rxblocknum,
					  init->rxblocksize);
	else
		rval = sblock_create(init->dst,
				     init->channel,
				     init->txblocknum,
				     init->txblocksize,
				     init->rxblocknum,
				     init->rxblocksize);
	if (rval) {
		pr_info("Failed to create sblock: %d\n", rval);
		goto free_devno;
	}

	spool = devm_kzalloc(&pdev->dev,
			     sizeof(struct spool_device),
			     GFP_KERNEL);
	if (!spool) {
		pr_info("Failed to allocate spool_device\n");
		rval = -ENOMEM;
		goto free_sblock;
	}

	spool->init = init;
	spool->major = MAJOR(dev_no);
	spool->minor = MINOR(dev_no);
	spool->plt_dev = pdev;

	if (!init->nodev) {
		cdev_init(&spool->cdev, &spool_fops);

		rval = cdev_add(&spool->cdev, dev_no, 1);
		if (rval) {
			pr_info("Failed to add spool cdev\n");
			goto free_spool;
		}
	}

	spool->sys_dev = device_create(spool_class, NULL,
				       dev_no,
				       spool, "%s", init->name);
	device_create_file(&pdev->dev, &dev_attr_base_addr);

	platform_set_drvdata(pdev, spool);

	*out = spool;

	return 0;

free_spool:
	devm_kfree(&pdev->dev, spool);

free_sblock:
	sblock_destroy(init->dst, init->channel);

free_devno:
	unregister_chrdev_region(dev_no, 1);
	return rval;
}

static int destroy_spool(struct spool_device *spool)
{
	dev_t dev_no = MKDEV(spool->major, spool->minor);
	struct spool_init_data *init = spool->init;

	if (spool->sys_dev) {
		device_destroy(spool_class, dev_no);
		spool->sys_dev = NULL;
	}
	if (!init->nodev)
		cdev_del(&spool->cdev);
	sblock_destroy(init->dst, init->channel);
	unregister_chrdev_region(dev_no, 1);
	devm_kfree(&spool->plt_dev->dev, init);
	devm_kfree(&spool->plt_dev->dev, spool);

	return 0;
}

static int spool_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	int rval;
	struct spool_init_data *init;
	struct spool_device *spool;
	dev_t dev_no;

#ifdef SPRD_PCIE_USE_DTS
	if (!np)
		return -ENODEV;
#endif

	rval = spool_parse_dt(&init, &pdev->dev, np, &dev_no);
	if (rval) {
		pr_err("Failed to parse spool device tree, ret=%d\n",
		       rval);
		return rval;
	}

	pr_info("spool: name=%s, dst=%u, channel=%u, pre_cfg=%u\n",
		init->name,
		init->dst,
		init->channel,
		init->pre_cfg);

	pr_info("spool: tx_num=%u, tx_size=%u, rx_num=%u, rx_size=%u\n",
		init->txblocknum,
		init->txblocksize,
		init->rxblocknum,
		init->rxblocksize);

	rval = create_spool(pdev, init, &spool, dev_no);
	if (rval) {
		pr_err("Failed to create spool device %u:%u, ret=%d\n",
		       (unsigned int)init->dst,
		       (unsigned int)init->channel, rval);
		devm_kfree(&pdev->dev, init);
	}

	return 0;
}

static int spool_remove(struct platform_device *pdev)
{
	struct spool_device *priv = (struct spool_device *)
		platform_get_drvdata(pdev);

	destroy_spool(priv);

	platform_set_drvdata(pdev, NULL);

	return 0;
}

#ifdef SPRD_PCIE_USE_DTS
static const struct of_device_id spool_match_table[] = {
	{ .compatible = "sprd,spool", },
	{ },
};
#endif

static struct platform_driver spool_driver = {
	.driver = {
		.owner = THIS_MODULE,
		.name = "spool",
#ifdef SPRD_PCIE_USE_DTS
		.of_match_table = spool_match_table,
#endif
	},
	.probe = spool_probe,
	.remove = spool_remove,
};

#ifndef SPRD_PCIE_USE_DTS
static void spool_platform_device_release(struct device *dev) {}
static struct platform_device spool_device = {
    	.name        = "spool",
    	.id        = -1,
		.dev = {
			.release = spool_platform_device_release,
		}
};
#endif

int spool_init(void)
{
	int ret;

	spool_class = class_create(THIS_MODULE, "spool");
	if (IS_ERR(spool_class))
		return PTR_ERR(spool_class);
#ifndef SPRD_PCIE_USE_DTS
        if((ret = platform_device_register(&spool_device)))
		return ret;
#endif
	if((ret  = platform_driver_register(&spool_driver))) {
#ifndef SPRD_PCIE_USE_DTS
		platform_device_unregister(&spool_device);
#endif
		return ret;
        }

	return ret;
}
EXPORT_SYMBOL_GPL(spool_init);

void spool_exit(void)
{
	platform_driver_unregister(&spool_driver);
#ifndef SPRD_PCIE_USE_DTS
	platform_device_unregister(&spool_device);
#endif
	class_destroy(spool_class);
}


void spool_device_down(void) 
{
    sblock_down(1, 5);
}

EXPORT_SYMBOL_GPL(spool_exit);
EXPORT_SYMBOL_GPL(spool_device_down);