// SPDX-License-Identifier: GPL-2.0+
//
// Copyright (c) 2013-2014 Freescale Semiconductor, Inc
// Copyright (c) 2017 Sysam, Angelo Dureghello  <angelo@sysam.it>

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/platform_device.h>
#include <linux/platform_data/dma-mcf-edma.h>

#include "fsl-edma-common.h"

#define EDMA_CHANNELS		64
#define EDMA_MASK_CH(x)		((x) & GENMASK(5, 0))

static irqreturn_t mcf_edma_tx_handler(int irq, void *dev_id)
{
	struct fsl_edma_engine *mcf_edma = dev_id;
	struct edma_regs *regs = &mcf_edma->regs;
	unsigned int ch;
	struct fsl_edma_chan *mcf_chan;
	u64 intmap;

	intmap = ioread32(regs->inth);
	intmap <<= 32;
	intmap |= ioread32(regs->intl);
	if (!intmap)
		return IRQ_NONE;

	for (ch = 0; ch < mcf_edma->n_chans; ch++) {
		if (intmap & BIT(ch)) {
			iowrite8(EDMA_MASK_CH(ch), regs->cint);

			mcf_chan = &mcf_edma->chans[ch];

			spin_lock(&mcf_chan->vchan.lock);

			if (!mcf_chan->edesc) {
				/* terminate_all called before */
				spin_unlock(&mcf_chan->vchan.lock);
				continue;
			}

			if (!mcf_chan->edesc->iscyclic) {
				list_del(&mcf_chan->edesc->vdesc.node);
				vchan_cookie_complete(&mcf_chan->edesc->vdesc);
				mcf_chan->edesc = NULL;
				mcf_chan->status = DMA_COMPLETE;
				mcf_chan->idle = true;
			} else {
				vchan_cyclic_callback(&mcf_chan->edesc->vdesc);
			}

			if (!mcf_chan->edesc)
				fsl_edma_xfer_desc(mcf_chan);

			spin_unlock(&mcf_chan->vchan.lock);
		}
	}

	return IRQ_HANDLED;
}

static irqreturn_t mcf_edma_err_handler(int irq, void *dev_id)
{
	struct fsl_edma_engine *mcf_edma = dev_id;
	struct edma_regs *regs = &mcf_edma->regs;
	unsigned int err, ch;

	err = ioread32(regs->errl);
	if (!err)
		return IRQ_NONE;

	for (ch = 0; ch < (EDMA_CHANNELS / 2); ch++) {
		if (err & BIT(ch)) {
			fsl_edma_disable_request(&mcf_edma->chans[ch]);
			iowrite8(EDMA_CERR_CERR(ch), regs->cerr);
			mcf_edma->chans[ch].status = DMA_ERROR;
			mcf_edma->chans[ch].idle = true;
		}
	}

	err = ioread32(regs->errh);
	if (!err)
		return IRQ_NONE;

	for (ch = (EDMA_CHANNELS / 2); ch < EDMA_CHANNELS; ch++) {
		if (err & (BIT(ch - (EDMA_CHANNELS / 2)))) {
			fsl_edma_disable_request(&mcf_edma->chans[ch]);
			iowrite8(EDMA_CERR_CERR(ch), regs->cerr);
			mcf_edma->chans[ch].status = DMA_ERROR;
			mcf_edma->chans[ch].idle = true;
		}
	}

	return IRQ_HANDLED;
}

static int mcf_edma_irq_init(struct platform_device *pdev,
				struct fsl_edma_engine *mcf_edma)
{
	int ret = 0, i;
	struct resource *res;

	res = platform_get_resource_byname(pdev,
				IORESOURCE_IRQ, "edma-tx-00-15");
	if (!res)
		return -1;

	for (ret = 0, i = res->start; i <= res->end; ++i)
		ret |= request_irq(i, mcf_edma_tx_handler, 0, "eDMA", mcf_edma);
	if (ret)
		return ret;

	res = platform_get_resource_byname(pdev,
			IORESOURCE_IRQ, "edma-tx-16-55");
	if (!res)
		return -1;

	for (ret = 0, i = res->start; i <= res->end; ++i)
		ret |= request_irq(i, mcf_edma_tx_handler, 0, "eDMA", mcf_edma);
	if (ret)
		return ret;

	ret = platform_get_irq_byname(pdev, "edma-tx-56-63");
	if (ret != -ENXIO) {
		ret = request_irq(ret, mcf_edma_tx_handler,
				  0, "eDMA", mcf_edma);
		if (ret)
			return ret;
	}

	ret = platform_get_irq_byname(pdev, "edma-err");
	if (ret != -ENXIO) {
		ret = request_irq(ret, mcf_edma_err_handler,
				  0, "eDMA", mcf_edma);
		if (ret)
			return ret;
	}

	return 0;
}

static void mcf_edma_irq_free(struct platform_device *pdev,
				struct fsl_edma_engine *mcf_edma)
{
	int irq;
	struct resource *res;

	res = platform_get_resource_byname(pdev,
			IORESOURCE_IRQ, "edma-tx-00-15");
	if (res) {
		for (irq = res->start; irq <= res->end; irq++)
			free_irq(irq, mcf_edma);
	}

	res = platform_get_resource_byname(pdev,
			IORESOURCE_IRQ, "edma-tx-16-55");
	if (res) {
		for (irq = res->start; irq <= res->end; irq++)
			free_irq(irq, mcf_edma);
	}

	irq = platform_get_irq_byname(pdev, "edma-tx-56-63");
	if (irq != -ENXIO)
		free_irq(irq, mcf_edma);

	irq = platform_get_irq_byname(pdev, "edma-err");
	if (irq != -ENXIO)
		free_irq(irq, mcf_edma);
}

static struct fsl_edma_drvdata mcf_data = {
	.version = v2,
	.setup_irq = mcf_edma_irq_init,
};

static int mcf_edma_probe(struct platform_device *pdev)
{
	struct mcf_edma_platform_data *pdata;
	struct fsl_edma_engine *mcf_edma;
	struct fsl_edma_chan *mcf_chan;
	struct edma_regs *regs;
	struct resource *res;
	int ret, i, len, chans;

	pdata = dev_get_platdata(&pdev->dev);
	if (!pdata) {
		dev_err(&pdev->dev, "no platform data supplied\n");
		return -EINVAL;
	}

	if (!pdata->dma_channels) {
		dev_info(&pdev->dev, "setting default channel number to 64");
		chans = 64;
	} else {
		chans = pdata->dma_channels;
	}

	len = sizeof(*mcf_edma) + sizeof(*mcf_chan) * chans;
	mcf_edma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
	if (!mcf_edma)
		return -ENOMEM;

	mcf_edma->n_chans = chans;

	/* Set up drvdata for ColdFire edma */
	mcf_edma->drvdata = &mcf_data;
	mcf_edma->big_endian = 1;

	mutex_init(&mcf_edma->fsl_edma_mutex);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	mcf_edma->membase = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(mcf_edma->membase))
		return PTR_ERR(mcf_edma->membase);

	fsl_edma_setup_regs(mcf_edma);
	regs = &mcf_edma->regs;

	INIT_LIST_HEAD(&mcf_edma->dma_dev.channels);
	for (i = 0; i < mcf_edma->n_chans; i++) {
		struct fsl_edma_chan *mcf_chan = &mcf_edma->chans[i];

		mcf_chan->edma = mcf_edma;
		mcf_chan->slave_id = i;
		mcf_chan->idle = true;
		mcf_chan->dma_dir = DMA_NONE;
		mcf_chan->vchan.desc_free = fsl_edma_free_desc;
		vchan_init(&mcf_chan->vchan, &mcf_edma->dma_dev);
		iowrite32(0x0, &regs->tcd[i].csr);
	}

	iowrite32(~0, regs->inth);
	iowrite32(~0, regs->intl);

	ret = mcf_edma->drvdata->setup_irq(pdev, mcf_edma);
	if (ret)
		return ret;

	dma_cap_set(DMA_PRIVATE, mcf_edma->dma_dev.cap_mask);
	dma_cap_set(DMA_SLAVE, mcf_edma->dma_dev.cap_mask);
	dma_cap_set(DMA_CYCLIC, mcf_edma->dma_dev.cap_mask);

	mcf_edma->dma_dev.dev = &pdev->dev;
	mcf_edma->dma_dev.device_alloc_chan_resources =
			fsl_edma_alloc_chan_resources;
	mcf_edma->dma_dev.device_free_chan_resources =
			fsl_edma_free_chan_resources;
	mcf_edma->dma_dev.device_config = fsl_edma_slave_config;
	mcf_edma->dma_dev.device_prep_dma_cyclic =
			fsl_edma_prep_dma_cyclic;
	mcf_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
	mcf_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
	mcf_edma->dma_dev.device_pause = fsl_edma_pause;
	mcf_edma->dma_dev.device_resume = fsl_edma_resume;
	mcf_edma->dma_dev.device_terminate_all = fsl_edma_terminate_all;
	mcf_edma->dma_dev.device_issue_pending = fsl_edma_issue_pending;

	mcf_edma->dma_dev.src_addr_widths = FSL_EDMA_BUSWIDTHS;
	mcf_edma->dma_dev.dst_addr_widths = FSL_EDMA_BUSWIDTHS;
	mcf_edma->dma_dev.directions =
			BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);

	mcf_edma->dma_dev.filter.fn = mcf_edma_filter_fn;
	mcf_edma->dma_dev.filter.map = pdata->slave_map;
	mcf_edma->dma_dev.filter.mapcnt = pdata->slavecnt;

	platform_set_drvdata(pdev, mcf_edma);

	ret = dma_async_device_register(&mcf_edma->dma_dev);
	if (ret) {
		dev_err(&pdev->dev,
			"Can't register Freescale eDMA engine. (%d)\n", ret);
		return ret;
	}

	/* Enable round robin arbitration */
	iowrite32(EDMA_CR_ERGA | EDMA_CR_ERCA, regs->cr);

	return 0;
}

static int mcf_edma_remove(struct platform_device *pdev)
{
	struct fsl_edma_engine *mcf_edma = platform_get_drvdata(pdev);

	mcf_edma_irq_free(pdev, mcf_edma);
	fsl_edma_cleanup_vchan(&mcf_edma->dma_dev);
	dma_async_device_unregister(&mcf_edma->dma_dev);

	return 0;
}

static struct platform_driver mcf_edma_driver = {
	.driver		= {
		.name	= "mcf-edma",
	},
	.probe		= mcf_edma_probe,
	.remove		= mcf_edma_remove,
};

bool mcf_edma_filter_fn(struct dma_chan *chan, void *param)
{
	if (chan->device->dev->driver == &mcf_edma_driver.driver) {
		struct fsl_edma_chan *mcf_chan = to_fsl_edma_chan(chan);

		return (mcf_chan->slave_id == (uintptr_t)param);
	}

	return false;
}
EXPORT_SYMBOL(mcf_edma_filter_fn);

static int __init mcf_edma_init(void)
{
	return platform_driver_register(&mcf_edma_driver);
}
subsys_initcall(mcf_edma_init);

static void __exit mcf_edma_exit(void)
{
	platform_driver_unregister(&mcf_edma_driver);
}
module_exit(mcf_edma_exit);

MODULE_ALIAS("platform:mcf-edma");
MODULE_DESCRIPTION("Freescale eDMA engine driver, ColdFire family");
MODULE_LICENSE("GPL v2");