root/drivers/dma/mcf-edma-main.c
// 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;
        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);
                        fsl_edma_tx_chan_handler(&mcf_edma->chans[ch]);
                }
        }

        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);
                        fsl_edma_err_chan_handler(&mcf_edma->chans[ch]);
                }
        }

        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;
                }
        }

        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 = {
        .flags = FSL_EDMA_DRV_EDMA64,
        .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 edma_regs *regs;
        int ret, i, 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;
        }

        mcf_edma = devm_kzalloc(&pdev->dev, struct_size(mcf_edma, chans, chans),
                                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);

        mcf_edma->membase = devm_platform_ioremap_resource(pdev, 0);
        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->srcid = i;
                mcf_chan->dma_dir = DMA_NONE;
                mcf_chan->vchan.desc_free = fsl_edma_free_desc;
                vchan_init(&mcf_chan->vchan, &mcf_edma->dma_dev);
                mcf_chan->tcd = mcf_edma->membase + EDMA_TCD
                                + i * sizeof(struct fsl_edma_hw_tcd);
                edma_write_tcdreg(mcf_chan, cpu_to_le32(0), 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 void 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);
}

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->srcid == (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");