// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018-2019 Synopsys, Inc. and/or its affiliates.
 * Synopsys DesignWare eDMA PCIe driver
 *
 * Author: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/device.h>
#include <linux/dma/edma.h>
#include <linux/pci-epf.h>
#include <linux/msi.h>
#include <linux/bitfield.h>

#include "dw-edma-core.h"

#define DW_PCIE_VSEC_DMA_ID                     0x6
#define DW_PCIE_VSEC_DMA_BAR                    GENMASK(10, 8)
#define DW_PCIE_VSEC_DMA_MAP                    GENMASK(2, 0)
#define DW_PCIE_VSEC_DMA_WR_CH                  GENMASK(9, 0)
#define DW_PCIE_VSEC_DMA_RD_CH                  GENMASK(25, 16)

#define DW_BLOCK(a, b, c) \
        { \
                .bar = a, \
                .off = b, \
                .sz = c, \
        },

struct dw_edma_block {
        enum pci_barno                  bar;
        off_t                           off;
        size_t                          sz;
};

struct dw_edma_pcie_data {
        /* eDMA registers location */
        struct dw_edma_block            rg;
        /* eDMA memory linked list location */
        struct dw_edma_block            ll_wr[EDMA_MAX_WR_CH];
        struct dw_edma_block            ll_rd[EDMA_MAX_RD_CH];
        /* eDMA memory data location */
        struct dw_edma_block            dt_wr[EDMA_MAX_WR_CH];
        struct dw_edma_block            dt_rd[EDMA_MAX_RD_CH];
        /* Other */
        enum dw_edma_map_format         mf;
        u8                              irqs;
        u16                             wr_ch_cnt;
        u16                             rd_ch_cnt;
};

static const struct dw_edma_pcie_data snps_edda_data = {
        /* eDMA registers location */
        .rg.bar                         = BAR_0,
        .rg.off                         = 0x00001000,   /*  4 Kbytes */
        .rg.sz                          = 0x00002000,   /*  8 Kbytes */
        /* eDMA memory linked list location */
        .ll_wr = {
                /* Channel 0 - BAR 2, offset 0 Mbytes, size 2 Kbytes */
                DW_BLOCK(BAR_2, 0x00000000, 0x00000800)
                /* Channel 1 - BAR 2, offset 2 Mbytes, size 2 Kbytes */
                DW_BLOCK(BAR_2, 0x00200000, 0x00000800)
        },
        .ll_rd = {
                /* Channel 0 - BAR 2, offset 4 Mbytes, size 2 Kbytes */
                DW_BLOCK(BAR_2, 0x00400000, 0x00000800)
                /* Channel 1 - BAR 2, offset 6 Mbytes, size 2 Kbytes */
                DW_BLOCK(BAR_2, 0x00600000, 0x00000800)
        },
        /* eDMA memory data location */
        .dt_wr = {
                /* Channel 0 - BAR 2, offset 8 Mbytes, size 2 Kbytes */
                DW_BLOCK(BAR_2, 0x00800000, 0x00000800)
                /* Channel 1 - BAR 2, offset 9 Mbytes, size 2 Kbytes */
                DW_BLOCK(BAR_2, 0x00900000, 0x00000800)
        },
        .dt_rd = {
                /* Channel 0 - BAR 2, offset 10 Mbytes, size 2 Kbytes */
                DW_BLOCK(BAR_2, 0x00a00000, 0x00000800)
                /* Channel 1 - BAR 2, offset 11 Mbytes, size 2 Kbytes */
                DW_BLOCK(BAR_2, 0x00b00000, 0x00000800)
        },
        /* Other */
        .mf                             = EDMA_MF_EDMA_UNROLL,
        .irqs                           = 1,
        .wr_ch_cnt                      = 2,
        .rd_ch_cnt                      = 2,
};

static int dw_edma_pcie_irq_vector(struct device *dev, unsigned int nr)
{
        return pci_irq_vector(to_pci_dev(dev), nr);
}

static u64 dw_edma_pcie_address(struct device *dev, phys_addr_t cpu_addr)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        struct pci_bus_region region;
        struct resource res = {
                .flags = IORESOURCE_MEM,
                .start = cpu_addr,
                .end = cpu_addr,
        };

        pcibios_resource_to_bus(pdev->bus, &region, &res);
        return region.start;
}

static const struct dw_edma_plat_ops dw_edma_pcie_plat_ops = {
        .irq_vector = dw_edma_pcie_irq_vector,
        .pci_address = dw_edma_pcie_address,
};

static void dw_edma_pcie_get_vsec_dma_data(struct pci_dev *pdev,
                                           struct dw_edma_pcie_data *pdata)
{
        u32 val, map;
        u16 vsec;
        u64 off;

        vsec = pci_find_vsec_capability(pdev, PCI_VENDOR_ID_SYNOPSYS,
                                        DW_PCIE_VSEC_DMA_ID);
        if (!vsec)
                return;

        pci_read_config_dword(pdev, vsec + PCI_VNDR_HEADER, &val);
        if (PCI_VNDR_HEADER_REV(val) != 0x00 ||
            PCI_VNDR_HEADER_LEN(val) != 0x18)
                return;

        pci_dbg(pdev, "Detected PCIe Vendor-Specific Extended Capability DMA\n");
        pci_read_config_dword(pdev, vsec + 0x8, &val);
        map = FIELD_GET(DW_PCIE_VSEC_DMA_MAP, val);
        if (map != EDMA_MF_EDMA_LEGACY &&
            map != EDMA_MF_EDMA_UNROLL &&
            map != EDMA_MF_HDMA_COMPAT &&
            map != EDMA_MF_HDMA_NATIVE)
                return;

        pdata->mf = map;
        pdata->rg.bar = FIELD_GET(DW_PCIE_VSEC_DMA_BAR, val);

        pci_read_config_dword(pdev, vsec + 0xc, &val);
        pdata->wr_ch_cnt = min_t(u16, pdata->wr_ch_cnt,
                                 FIELD_GET(DW_PCIE_VSEC_DMA_WR_CH, val));
        pdata->rd_ch_cnt = min_t(u16, pdata->rd_ch_cnt,
                                 FIELD_GET(DW_PCIE_VSEC_DMA_RD_CH, val));

        pci_read_config_dword(pdev, vsec + 0x14, &val);
        off = val;
        pci_read_config_dword(pdev, vsec + 0x10, &val);
        off <<= 32;
        off |= val;
        pdata->rg.off = off;
}

static int dw_edma_pcie_probe(struct pci_dev *pdev,
                              const struct pci_device_id *pid)
{
        struct dw_edma_pcie_data *pdata = (void *)pid->driver_data;
        struct device *dev = &pdev->dev;
        struct dw_edma_chip *chip;
        int err, nr_irqs;
        int i, mask;

        struct dw_edma_pcie_data *vsec_data __free(kfree) =
                kmalloc_obj(*vsec_data);
        if (!vsec_data)
                return -ENOMEM;

        /* Enable PCI device */
        err = pcim_enable_device(pdev);
        if (err) {
                pci_err(pdev, "enabling device failed\n");
                return err;
        }

        memcpy(vsec_data, pdata, sizeof(struct dw_edma_pcie_data));

        /*
         * Tries to find if exists a PCIe Vendor-Specific Extended Capability
         * for the DMA, if one exists, then reconfigures it.
         */
        dw_edma_pcie_get_vsec_dma_data(pdev, vsec_data);

        /* Mapping PCI BAR regions */
        mask = BIT(vsec_data->rg.bar);
        for (i = 0; i < vsec_data->wr_ch_cnt; i++) {
                mask |= BIT(vsec_data->ll_wr[i].bar);
                mask |= BIT(vsec_data->dt_wr[i].bar);
        }
        for (i = 0; i < vsec_data->rd_ch_cnt; i++) {
                mask |= BIT(vsec_data->ll_rd[i].bar);
                mask |= BIT(vsec_data->dt_rd[i].bar);
        }
        err = pcim_iomap_regions(pdev, mask, pci_name(pdev));
        if (err) {
                pci_err(pdev, "eDMA BAR I/O remapping failed\n");
                return err;
        }

        pci_set_master(pdev);

        /* DMA configuration */
        err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
        if (err) {
                pci_err(pdev, "DMA mask 64 set failed\n");
                return err;
        }

        /* Data structure allocation */
        chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        /* IRQs allocation */
        nr_irqs = pci_alloc_irq_vectors(pdev, 1, vsec_data->irqs,
                                        PCI_IRQ_MSI | PCI_IRQ_MSIX);
        if (nr_irqs < 1) {
                pci_err(pdev, "fail to alloc IRQ vector (number of IRQs=%u)\n",
                        nr_irqs);
                return -EPERM;
        }

        /* Data structure initialization */
        chip->dev = dev;

        chip->mf = vsec_data->mf;
        chip->nr_irqs = nr_irqs;
        chip->ops = &dw_edma_pcie_plat_ops;

        chip->ll_wr_cnt = vsec_data->wr_ch_cnt;
        chip->ll_rd_cnt = vsec_data->rd_ch_cnt;

        chip->reg_base = pcim_iomap_table(pdev)[vsec_data->rg.bar];
        if (!chip->reg_base)
                return -ENOMEM;

        for (i = 0; i < chip->ll_wr_cnt; i++) {
                struct dw_edma_region *ll_region = &chip->ll_region_wr[i];
                struct dw_edma_region *dt_region = &chip->dt_region_wr[i];
                struct dw_edma_block *ll_block = &vsec_data->ll_wr[i];
                struct dw_edma_block *dt_block = &vsec_data->dt_wr[i];

                ll_region->vaddr.io = pcim_iomap_table(pdev)[ll_block->bar];
                if (!ll_region->vaddr.io)
                        return -ENOMEM;

                ll_region->vaddr.io += ll_block->off;
                ll_region->paddr = pci_bus_address(pdev, ll_block->bar);
                ll_region->paddr += ll_block->off;
                ll_region->sz = ll_block->sz;

                dt_region->vaddr.io = pcim_iomap_table(pdev)[dt_block->bar];
                if (!dt_region->vaddr.io)
                        return -ENOMEM;

                dt_region->vaddr.io += dt_block->off;
                dt_region->paddr = pci_bus_address(pdev, dt_block->bar);
                dt_region->paddr += dt_block->off;
                dt_region->sz = dt_block->sz;
        }

        for (i = 0; i < chip->ll_rd_cnt; i++) {
                struct dw_edma_region *ll_region = &chip->ll_region_rd[i];
                struct dw_edma_region *dt_region = &chip->dt_region_rd[i];
                struct dw_edma_block *ll_block = &vsec_data->ll_rd[i];
                struct dw_edma_block *dt_block = &vsec_data->dt_rd[i];

                ll_region->vaddr.io = pcim_iomap_table(pdev)[ll_block->bar];
                if (!ll_region->vaddr.io)
                        return -ENOMEM;

                ll_region->vaddr.io += ll_block->off;
                ll_region->paddr = pci_bus_address(pdev, ll_block->bar);
                ll_region->paddr += ll_block->off;
                ll_region->sz = ll_block->sz;

                dt_region->vaddr.io = pcim_iomap_table(pdev)[dt_block->bar];
                if (!dt_region->vaddr.io)
                        return -ENOMEM;

                dt_region->vaddr.io += dt_block->off;
                dt_region->paddr = pci_bus_address(pdev, dt_block->bar);
                dt_region->paddr += dt_block->off;
                dt_region->sz = dt_block->sz;
        }

        /* Debug info */
        if (chip->mf == EDMA_MF_EDMA_LEGACY)
                pci_dbg(pdev, "Version:\teDMA Port Logic (0x%x)\n", chip->mf);
        else if (chip->mf == EDMA_MF_EDMA_UNROLL)
                pci_dbg(pdev, "Version:\teDMA Unroll (0x%x)\n", chip->mf);
        else if (chip->mf == EDMA_MF_HDMA_COMPAT)
                pci_dbg(pdev, "Version:\tHDMA Compatible (0x%x)\n", chip->mf);
        else if (chip->mf == EDMA_MF_HDMA_NATIVE)
                pci_dbg(pdev, "Version:\tHDMA Native (0x%x)\n", chip->mf);
        else
                pci_dbg(pdev, "Version:\tUnknown (0x%x)\n", chip->mf);

        pci_dbg(pdev, "Registers:\tBAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p)\n",
                vsec_data->rg.bar, vsec_data->rg.off, vsec_data->rg.sz,
                chip->reg_base);


        for (i = 0; i < chip->ll_wr_cnt; i++) {
                pci_dbg(pdev, "L. List:\tWRITE CH%.2u, BAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
                        i, vsec_data->ll_wr[i].bar,
                        vsec_data->ll_wr[i].off, chip->ll_region_wr[i].sz,
                        chip->ll_region_wr[i].vaddr.io, &chip->ll_region_wr[i].paddr);

                pci_dbg(pdev, "Data:\tWRITE CH%.2u, BAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
                        i, vsec_data->dt_wr[i].bar,
                        vsec_data->dt_wr[i].off, chip->dt_region_wr[i].sz,
                        chip->dt_region_wr[i].vaddr.io, &chip->dt_region_wr[i].paddr);
        }

        for (i = 0; i < chip->ll_rd_cnt; i++) {
                pci_dbg(pdev, "L. List:\tREAD CH%.2u, BAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
                        i, vsec_data->ll_rd[i].bar,
                        vsec_data->ll_rd[i].off, chip->ll_region_rd[i].sz,
                        chip->ll_region_rd[i].vaddr.io, &chip->ll_region_rd[i].paddr);

                pci_dbg(pdev, "Data:\tREAD CH%.2u, BAR=%u, off=0x%.8lx, sz=0x%zx bytes, addr(v=%p, p=%pa)\n",
                        i, vsec_data->dt_rd[i].bar,
                        vsec_data->dt_rd[i].off, chip->dt_region_rd[i].sz,
                        chip->dt_region_rd[i].vaddr.io, &chip->dt_region_rd[i].paddr);
        }

        pci_dbg(pdev, "Nr. IRQs:\t%u\n", chip->nr_irqs);

        /* Validating if PCI interrupts were enabled */
        if (!pci_dev_msi_enabled(pdev)) {
                pci_err(pdev, "enable interrupt failed\n");
                return -EPERM;
        }

        /* Starting eDMA driver */
        err = dw_edma_probe(chip);
        if (err) {
                pci_err(pdev, "eDMA probe failed\n");
                return err;
        }

        /* Saving data structure reference */
        pci_set_drvdata(pdev, chip);

        return 0;
}

static void dw_edma_pcie_remove(struct pci_dev *pdev)
{
        struct dw_edma_chip *chip = pci_get_drvdata(pdev);
        int err;

        /* Stopping eDMA driver */
        err = dw_edma_remove(chip);
        if (err)
                pci_warn(pdev, "can't remove device properly: %d\n", err);

        /* Freeing IRQs */
        pci_free_irq_vectors(pdev);
}

static const struct pci_device_id dw_edma_pcie_id_table[] = {
        { PCI_DEVICE_DATA(SYNOPSYS, EDDA, &snps_edda_data) },
        { }
};
MODULE_DEVICE_TABLE(pci, dw_edma_pcie_id_table);

static struct pci_driver dw_edma_pcie_driver = {
        .name           = "dw-edma-pcie",
        .id_table       = dw_edma_pcie_id_table,
        .probe          = dw_edma_pcie_probe,
        .remove         = dw_edma_pcie_remove,
};

module_pci_driver(dw_edma_pcie_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Synopsys DesignWare eDMA PCIe driver");
MODULE_AUTHOR("Gustavo Pimentel <gustavo.pimentel@synopsys.com>");