// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
 *  Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
 */
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/of_platform.h>

#define TI_XBAR_DRA7            0
#define TI_XBAR_AM335X          1
static const u32 ti_xbar_type[] = {
        [TI_XBAR_DRA7] = TI_XBAR_DRA7,
        [TI_XBAR_AM335X] = TI_XBAR_AM335X,
};

static const struct of_device_id ti_dma_xbar_match[] = {
        {
                .compatible = "ti,dra7-dma-crossbar",
                .data = &ti_xbar_type[TI_XBAR_DRA7],
        },
        {
                .compatible = "ti,am335x-edma-crossbar",
                .data = &ti_xbar_type[TI_XBAR_AM335X],
        },
        {},
};

/* Crossbar on AM335x/AM437x family */
#define TI_AM335X_XBAR_LINES    64

struct ti_am335x_xbar_data {
        void __iomem *iomem;

        struct dma_router dmarouter;

        u32 xbar_events; /* maximum number of events to select in xbar */
        u32 dma_requests; /* number of DMA requests on eDMA */
};

struct ti_am335x_xbar_map {
        u16 dma_line;
        u8 mux_val;
};

static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u8 val)
{
        /*
         * TPCC_EVT_MUX_60_63 register layout is different than the
         * rest, in the sense, that event 63 is mapped to lowest byte
         * and event 60 is mapped to highest, handle it separately.
         */
        if (event >= 60 && event <= 63)
                writeb_relaxed(val, iomem + (63 - event % 4));
        else
                writeb_relaxed(val, iomem + event);
}

static void ti_am335x_xbar_free(struct device *dev, void *route_data)
{
        struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
        struct ti_am335x_xbar_map *map = route_data;

        dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
                map->mux_val, map->dma_line);

        ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
        kfree(map);
}

static void *ti_am335x_xbar_route_allocate(struct of_phandle_args *dma_spec,
                                           struct of_dma *ofdma)
{
        struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
        struct ti_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
        struct ti_am335x_xbar_map *map = ERR_PTR(-EINVAL);

        if (dma_spec->args_count != 3)
                goto out_put_pdev;

        if (dma_spec->args[2] >= xbar->xbar_events) {
                dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
                        dma_spec->args[2]);
                goto out_put_pdev;
        }

        if (dma_spec->args[0] >= xbar->dma_requests) {
                dev_err(&pdev->dev, "Invalid DMA request line number: %d\n",
                        dma_spec->args[0]);
                goto out_put_pdev;
        }

        /* The of_node_put() will be done in the core for the node */
        dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
        if (!dma_spec->np) {
                dev_err(&pdev->dev, "Can't get DMA master\n");
                goto out_put_pdev;
        }

        map = kzalloc_obj(*map);
        if (!map) {
                of_node_put(dma_spec->np);
                map = ERR_PTR(-ENOMEM);
                goto out_put_pdev;
        }

        map->dma_line = (u16)dma_spec->args[0];
        map->mux_val = (u8)dma_spec->args[2];

        dma_spec->args[2] = 0;
        dma_spec->args_count = 2;

        dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
                map->mux_val, map->dma_line);

        ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);

out_put_pdev:
        put_device(&pdev->dev);

        return map;
}

static const struct of_device_id ti_am335x_master_match[] __maybe_unused = {
        { .compatible = "ti,edma3-tpcc", },
        {},
};

static int ti_am335x_xbar_probe(struct platform_device *pdev)
{
        struct device_node *node = pdev->dev.of_node;
        const struct of_device_id *match;
        struct device_node *dma_node;
        struct ti_am335x_xbar_data *xbar;
        void __iomem *iomem;
        int i, ret;

        if (!node)
                return -ENODEV;

        xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
        if (!xbar)
                return -ENOMEM;

        dma_node = of_parse_phandle(node, "dma-masters", 0);
        if (!dma_node) {
                dev_err(&pdev->dev, "Can't get DMA master node\n");
                return -ENODEV;
        }

        match = of_match_node(ti_am335x_master_match, dma_node);
        if (!match) {
                dev_err(&pdev->dev, "DMA master is not supported\n");
                of_node_put(dma_node);
                return -EINVAL;
        }

        if (of_property_read_u32(dma_node, "dma-requests",
                                 &xbar->dma_requests)) {
                dev_info(&pdev->dev,
                         "Missing XBAR output information, using %u.\n",
                         TI_AM335X_XBAR_LINES);
                xbar->dma_requests = TI_AM335X_XBAR_LINES;
        }
        of_node_put(dma_node);

        if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
                dev_info(&pdev->dev,
                         "Missing XBAR input information, using %u.\n",
                         TI_AM335X_XBAR_LINES);
                xbar->xbar_events = TI_AM335X_XBAR_LINES;
        }

        iomem = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(iomem))
                return PTR_ERR(iomem);

        xbar->iomem = iomem;

        xbar->dmarouter.dev = &pdev->dev;
        xbar->dmarouter.route_free = ti_am335x_xbar_free;

        platform_set_drvdata(pdev, xbar);

        /* Reset the crossbar */
        for (i = 0; i < xbar->dma_requests; i++)
                ti_am335x_xbar_write(xbar->iomem, i, 0);

        ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
                                     &xbar->dmarouter);

        return ret;
}

/* Crossbar on DRA7xx family */
#define TI_DRA7_XBAR_OUTPUTS    127
#define TI_DRA7_XBAR_INPUTS     256

struct ti_dra7_xbar_data {
        void __iomem *iomem;

        struct dma_router dmarouter;
        struct mutex mutex;
        unsigned long *dma_inuse;

        u16 safe_val; /* Value to rest the crossbar lines */
        u32 xbar_requests; /* number of DMA requests connected to XBAR */
        u32 dma_requests; /* number of DMA requests forwarded to DMA */
        u32 dma_offset;
};

struct ti_dra7_xbar_map {
        u16 xbar_in;
        int xbar_out;
};

static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
{
        writew_relaxed(val, iomem + (xbar * 2));
}

static void ti_dra7_xbar_free(struct device *dev, void *route_data)
{
        struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
        struct ti_dra7_xbar_map *map = route_data;

        dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
                map->xbar_in, map->xbar_out);

        ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
        mutex_lock(&xbar->mutex);
        clear_bit(map->xbar_out, xbar->dma_inuse);
        mutex_unlock(&xbar->mutex);
        kfree(map);
}

static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec,
                                         struct of_dma *ofdma)
{
        struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
        struct ti_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
        struct ti_dra7_xbar_map *map = ERR_PTR(-EINVAL);

        if (dma_spec->args[0] >= xbar->xbar_requests) {
                dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
                        dma_spec->args[0]);
                goto out_put_pdev;
        }

        /* The of_node_put() will be done in the core for the node */
        dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
        if (!dma_spec->np) {
                dev_err(&pdev->dev, "Can't get DMA master\n");
                goto out_put_pdev;
        }

        map = kzalloc_obj(*map);
        if (!map) {
                of_node_put(dma_spec->np);
                map = ERR_PTR(-ENOMEM);
                goto out_put_pdev;
        }

        mutex_lock(&xbar->mutex);
        map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
                                            xbar->dma_requests);
        if (map->xbar_out == xbar->dma_requests) {
                mutex_unlock(&xbar->mutex);
                dev_err(&pdev->dev, "Run out of free DMA requests\n");
                kfree(map);
                of_node_put(dma_spec->np);
                map = ERR_PTR(-ENOMEM);
                goto out_put_pdev;
        }
        set_bit(map->xbar_out, xbar->dma_inuse);
        mutex_unlock(&xbar->mutex);

        map->xbar_in = (u16)dma_spec->args[0];

        dma_spec->args[0] = map->xbar_out + xbar->dma_offset;

        dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
                map->xbar_in, map->xbar_out);

        ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);

out_put_pdev:
        put_device(&pdev->dev);

        return map;
}

#define TI_XBAR_EDMA_OFFSET     0
#define TI_XBAR_SDMA_OFFSET     1
static const u32 ti_dma_offset[] = {
        [TI_XBAR_EDMA_OFFSET] = 0,
        [TI_XBAR_SDMA_OFFSET] = 1,
};

static const struct of_device_id ti_dra7_master_match[] __maybe_unused = {
        {
                .compatible = "ti,omap4430-sdma",
                .data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
        },
        {
                .compatible = "ti,edma3",
                .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
        },
        {
                .compatible = "ti,edma3-tpcc",
                .data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
        },
        {},
};

static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
{
        for (; len > 0; len--)
                set_bit(offset + (len - 1), p);
}

static int ti_dra7_xbar_probe(struct platform_device *pdev)
{
        struct device_node *node = pdev->dev.of_node;
        const struct of_device_id *match;
        struct device_node *dma_node;
        struct ti_dra7_xbar_data *xbar;
        struct property *prop;
        u32 safe_val;
        int sz;
        void __iomem *iomem;
        int i, ret;

        if (!node)
                return -ENODEV;

        xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
        if (!xbar)
                return -ENOMEM;

        dma_node = of_parse_phandle(node, "dma-masters", 0);
        if (!dma_node) {
                dev_err(&pdev->dev, "Can't get DMA master node\n");
                return -ENODEV;
        }

        match = of_match_node(ti_dra7_master_match, dma_node);
        if (!match) {
                dev_err(&pdev->dev, "DMA master is not supported\n");
                of_node_put(dma_node);
                return -EINVAL;
        }

        if (of_property_read_u32(dma_node, "dma-requests",
                                 &xbar->dma_requests)) {
                dev_info(&pdev->dev,
                         "Missing XBAR output information, using %u.\n",
                         TI_DRA7_XBAR_OUTPUTS);
                xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
        }
        of_node_put(dma_node);

        xbar->dma_inuse = devm_kcalloc(&pdev->dev,
                                       BITS_TO_LONGS(xbar->dma_requests),
                                       sizeof(unsigned long), GFP_KERNEL);
        if (!xbar->dma_inuse)
                return -ENOMEM;

        if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
                dev_info(&pdev->dev,
                         "Missing XBAR input information, using %u.\n",
                         TI_DRA7_XBAR_INPUTS);
                xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
        }

        if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
                xbar->safe_val = (u16)safe_val;


        prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
        if (prop) {
                const char pname[] = "ti,reserved-dma-request-ranges";
                u32 (*rsv_events)[2];
                size_t nelm = sz / sizeof(*rsv_events);
                int i;

                if (!nelm)
                        return -EINVAL;

                rsv_events = kzalloc_objs(*rsv_events, nelm);
                if (!rsv_events)
                        return -ENOMEM;

                ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
                                                 nelm * 2);
                if (ret) {
                        kfree(rsv_events);
                        return ret;
                }

                for (i = 0; i < nelm; i++) {
                        ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
                                             xbar->dma_inuse);
                }
                kfree(rsv_events);
        }

        iomem = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(iomem))
                return PTR_ERR(iomem);

        xbar->iomem = iomem;

        xbar->dmarouter.dev = &pdev->dev;
        xbar->dmarouter.route_free = ti_dra7_xbar_free;
        xbar->dma_offset = *(u32 *)match->data;

        mutex_init(&xbar->mutex);
        platform_set_drvdata(pdev, xbar);

        /* Reset the crossbar */
        for (i = 0; i < xbar->dma_requests; i++) {
                if (!test_bit(i, xbar->dma_inuse))
                        ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
        }

        ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
                                     &xbar->dmarouter);
        if (ret) {
                /* Restore the defaults for the crossbar */
                for (i = 0; i < xbar->dma_requests; i++) {
                        if (!test_bit(i, xbar->dma_inuse))
                                ti_dra7_xbar_write(xbar->iomem, i, i);
                }
        }

        return ret;
}

static int ti_dma_xbar_probe(struct platform_device *pdev)
{
        const struct of_device_id *match;
        int ret;

        match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
        if (unlikely(!match))
                return -EINVAL;

        switch (*(u32 *)match->data) {
        case TI_XBAR_DRA7:
                ret = ti_dra7_xbar_probe(pdev);
                break;
        case TI_XBAR_AM335X:
                ret = ti_am335x_xbar_probe(pdev);
                break;
        default:
                dev_err(&pdev->dev, "Unsupported crossbar\n");
                ret = -ENODEV;
                break;
        }

        return ret;
}

static struct platform_driver ti_dma_xbar_driver = {
        .driver = {
                .name = "ti-dma-crossbar",
                .of_match_table = ti_dma_xbar_match,
        },
        .probe  = ti_dma_xbar_probe,
};

static int omap_dmaxbar_init(void)
{
        return platform_driver_register(&ti_dma_xbar_driver);
}
arch_initcall(omap_dmaxbar_init);