// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright 2011 Freescale Semiconductor, Inc
 *
 * Freescale Integrated Flash Controller
 *
 * Author: Dipen Dudhat <Dipen.Dudhat@freescale.com>
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/compiler.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/fsl_ifc.h>
#include <linux/irqdomain.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>

struct fsl_ifc_ctrl *fsl_ifc_ctrl_dev;
EXPORT_SYMBOL(fsl_ifc_ctrl_dev);

/*
 * convert_ifc_address - convert the base address
 * @addr_base:  base address of the memory bank
 */
unsigned int convert_ifc_address(phys_addr_t addr_base)
{
        return addr_base & CSPR_BA;
}
EXPORT_SYMBOL(convert_ifc_address);

/*
 * fsl_ifc_find - find IFC bank
 * @addr_base:  base address of the memory bank
 *
 * This function walks IFC banks comparing "Base address" field of the CSPR
 * registers with the supplied addr_base argument. When bases match this
 * function returns bank number (starting with 0), otherwise it returns
 * appropriate errno value.
 */
int fsl_ifc_find(phys_addr_t addr_base)
{
        int i = 0;

        if (!fsl_ifc_ctrl_dev || !fsl_ifc_ctrl_dev->gregs)
                return -ENODEV;

        for (i = 0; i < fsl_ifc_ctrl_dev->banks; i++) {
                u32 cspr = ifc_in32(&fsl_ifc_ctrl_dev->gregs->cspr_cs[i].cspr);

                if (cspr & CSPR_V && (cspr & CSPR_BA) ==
                                convert_ifc_address(addr_base))
                        return i;
        }

        return -ENOENT;
}
EXPORT_SYMBOL(fsl_ifc_find);

static int fsl_ifc_ctrl_init(struct fsl_ifc_ctrl *ctrl)
{
        struct fsl_ifc_global __iomem *ifc = ctrl->gregs;

        /*
         * Clear all the common status and event registers
         */
        if (ifc_in32(&ifc->cm_evter_stat) & IFC_CM_EVTER_STAT_CSER)
                ifc_out32(IFC_CM_EVTER_STAT_CSER, &ifc->cm_evter_stat);

        /* enable all error and events */
        ifc_out32(IFC_CM_EVTER_EN_CSEREN, &ifc->cm_evter_en);

        /* enable all error and event interrupts */
        ifc_out32(IFC_CM_EVTER_INTR_EN_CSERIREN, &ifc->cm_evter_intr_en);
        ifc_out32(0x0, &ifc->cm_erattr0);
        ifc_out32(0x0, &ifc->cm_erattr1);

        return 0;
}

static void fsl_ifc_ctrl_remove(struct platform_device *dev)
{
        struct fsl_ifc_ctrl *ctrl = dev_get_drvdata(&dev->dev);

        of_platform_depopulate(&dev->dev);
        free_irq(ctrl->nand_irq, ctrl);
        free_irq(ctrl->irq, ctrl);

        irq_dispose_mapping(ctrl->nand_irq);
        irq_dispose_mapping(ctrl->irq);

        iounmap(ctrl->gregs);

        dev_set_drvdata(&dev->dev, NULL);
}

/*
 * NAND events are split between an operational interrupt which only
 * receives OPC, and an error interrupt that receives everything else,
 * including non-NAND errors.  Whichever interrupt gets to it first
 * records the status and wakes the wait queue.
 */
static DEFINE_SPINLOCK(nand_irq_lock);

static u32 check_nand_stat(struct fsl_ifc_ctrl *ctrl)
{
        struct fsl_ifc_runtime __iomem *ifc = ctrl->rregs;
        unsigned long flags;
        u32 stat;

        spin_lock_irqsave(&nand_irq_lock, flags);

        stat = ifc_in32(&ifc->ifc_nand.nand_evter_stat);
        if (stat) {
                ifc_out32(stat, &ifc->ifc_nand.nand_evter_stat);
                ctrl->nand_stat = stat;
                wake_up(&ctrl->nand_wait);
        }

        spin_unlock_irqrestore(&nand_irq_lock, flags);

        return stat;
}

static irqreturn_t fsl_ifc_nand_irq(int irqno, void *data)
{
        struct fsl_ifc_ctrl *ctrl = data;

        if (check_nand_stat(ctrl))
                return IRQ_HANDLED;

        return IRQ_NONE;
}

/*
 * NOTE: This interrupt is used to report ifc events of various kinds,
 * such as transaction errors on the chipselects.
 */
static irqreturn_t fsl_ifc_ctrl_irq(int irqno, void *data)
{
        struct fsl_ifc_ctrl *ctrl = data;
        struct fsl_ifc_global __iomem *ifc = ctrl->gregs;
        u32 err_axiid, err_srcid, status, cs_err, err_addr;
        irqreturn_t ret = IRQ_NONE;

        /* read for chip select error */
        cs_err = ifc_in32(&ifc->cm_evter_stat);
        if (cs_err) {
                dev_err(ctrl->dev, "transaction sent to IFC is not mapped to any memory bank 0x%08X\n",
                        cs_err);
                /* clear the chip select error */
                ifc_out32(IFC_CM_EVTER_STAT_CSER, &ifc->cm_evter_stat);

                /* read error attribute registers print the error information */
                status = ifc_in32(&ifc->cm_erattr0);
                err_addr = ifc_in32(&ifc->cm_erattr1);

                if (status & IFC_CM_ERATTR0_ERTYP_READ)
                        dev_err(ctrl->dev, "Read transaction error CM_ERATTR0 0x%08X\n",
                                status);
                else
                        dev_err(ctrl->dev, "Write transaction error CM_ERATTR0 0x%08X\n",
                                status);

                err_axiid = (status & IFC_CM_ERATTR0_ERAID) >>
                                        IFC_CM_ERATTR0_ERAID_SHIFT;
                dev_err(ctrl->dev, "AXI ID of the error transaction 0x%08X\n",
                        err_axiid);

                err_srcid = (status & IFC_CM_ERATTR0_ESRCID) >>
                                        IFC_CM_ERATTR0_ESRCID_SHIFT;
                dev_err(ctrl->dev, "SRC ID of the error transaction 0x%08X\n",
                        err_srcid);

                dev_err(ctrl->dev, "Transaction Address corresponding to error ERADDR 0x%08X\n",
                        err_addr);

                ret = IRQ_HANDLED;
        }

        if (check_nand_stat(ctrl))
                ret = IRQ_HANDLED;

        return ret;
}

/*
 * fsl_ifc_ctrl_probe
 *
 * called by device layer when it finds a device matching
 * one our driver can handled. This code allocates all of
 * the resources needed for the controller only.  The
 * resources for the NAND banks themselves are allocated
 * in the chip probe function.
 */
static int fsl_ifc_ctrl_probe(struct platform_device *dev)
{
        int ret = 0;
        int version, banks;
        void __iomem *addr;

        dev_info(&dev->dev, "Freescale Integrated Flash Controller\n");

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

        dev_set_drvdata(&dev->dev, fsl_ifc_ctrl_dev);

        /* IOMAP the entire IFC region */
        fsl_ifc_ctrl_dev->gregs = of_iomap(dev->dev.of_node, 0);
        if (!fsl_ifc_ctrl_dev->gregs) {
                dev_err(&dev->dev, "failed to get memory region\n");
                return -ENODEV;
        }

        if (of_property_read_bool(dev->dev.of_node, "little-endian")) {
                fsl_ifc_ctrl_dev->little_endian = true;
                dev_dbg(&dev->dev, "IFC REGISTERS are LITTLE endian\n");
        } else {
                fsl_ifc_ctrl_dev->little_endian = false;
                dev_dbg(&dev->dev, "IFC REGISTERS are BIG endian\n");
        }

        version = ifc_in32(&fsl_ifc_ctrl_dev->gregs->ifc_rev) &
                        FSL_IFC_VERSION_MASK;

        banks = (version == FSL_IFC_VERSION_1_0_0) ? 4 : 8;
        dev_info(&dev->dev, "IFC version %d.%d, %d banks\n",
                version >> 24, (version >> 16) & 0xf, banks);

        fsl_ifc_ctrl_dev->version = version;
        fsl_ifc_ctrl_dev->banks = banks;

        addr = fsl_ifc_ctrl_dev->gregs;
        if (version >= FSL_IFC_VERSION_2_0_0)
                addr += PGOFFSET_64K;
        else
                addr += PGOFFSET_4K;
        fsl_ifc_ctrl_dev->rregs = addr;

        /* get the Controller level irq */
        fsl_ifc_ctrl_dev->irq = irq_of_parse_and_map(dev->dev.of_node, 0);
        if (fsl_ifc_ctrl_dev->irq == 0) {
                dev_err(&dev->dev, "failed to get irq resource for IFC\n");
                ret = -ENODEV;
                goto err;
        }

        /* get the nand machine irq */
        fsl_ifc_ctrl_dev->nand_irq =
                        irq_of_parse_and_map(dev->dev.of_node, 1);

        fsl_ifc_ctrl_dev->dev = &dev->dev;

        ret = fsl_ifc_ctrl_init(fsl_ifc_ctrl_dev);
        if (ret < 0)
                goto err_unmap_nandirq;

        init_waitqueue_head(&fsl_ifc_ctrl_dev->nand_wait);

        ret = request_irq(fsl_ifc_ctrl_dev->irq, fsl_ifc_ctrl_irq, IRQF_SHARED,
                          "fsl-ifc", fsl_ifc_ctrl_dev);
        if (ret != 0) {
                dev_err(&dev->dev, "failed to install irq (%d)\n",
                        fsl_ifc_ctrl_dev->irq);
                goto err_unmap_nandirq;
        }

        if (fsl_ifc_ctrl_dev->nand_irq) {
                ret = request_irq(fsl_ifc_ctrl_dev->nand_irq, fsl_ifc_nand_irq,
                                0, "fsl-ifc-nand", fsl_ifc_ctrl_dev);
                if (ret != 0) {
                        dev_err(&dev->dev, "failed to install irq (%d)\n",
                                fsl_ifc_ctrl_dev->nand_irq);
                        goto err_free_irq;
                }
        }

        /* legacy dts may still use "simple-bus" compatible */
        ret = of_platform_default_populate(dev->dev.of_node, NULL, &dev->dev);
        if (ret)
                goto err_free_nandirq;

        return 0;

err_free_nandirq:
        free_irq(fsl_ifc_ctrl_dev->nand_irq, fsl_ifc_ctrl_dev);
err_free_irq:
        free_irq(fsl_ifc_ctrl_dev->irq, fsl_ifc_ctrl_dev);
err_unmap_nandirq:
        irq_dispose_mapping(fsl_ifc_ctrl_dev->nand_irq);
        irq_dispose_mapping(fsl_ifc_ctrl_dev->irq);
err:
        iounmap(fsl_ifc_ctrl_dev->gregs);
        return ret;
}

static const struct of_device_id fsl_ifc_match[] = {
        {
                .compatible = "fsl,ifc",
        },
        {},
};

static struct platform_driver fsl_ifc_ctrl_driver = {
        .driver = {
                .name   = "fsl-ifc",
                .of_match_table = fsl_ifc_match,
        },
        .probe       = fsl_ifc_ctrl_probe,
        .remove  = fsl_ifc_ctrl_remove,
};

static int __init fsl_ifc_init(void)
{
        return platform_driver_register(&fsl_ifc_ctrl_driver);
}
subsys_initcall(fsl_ifc_init);

MODULE_AUTHOR("Freescale Semiconductor");
MODULE_DESCRIPTION("Freescale Integrated Flash Controller driver");