/*
 * Freescale LBC and UPM routines.
 *
 * Copyright © 2007-2008  MontaVista Software, Inc.
 * Copyright © 2010 Freescale Semiconductor
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 * Author: Jack Lan <Jack.Lan@freescale.com>
 * Author: Roy Zang <tie-fei.zang@freescale.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/compiler.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/mod_devicetable.h>
#include <asm/prom.h>
#include <asm/fsl_lbc.h>

static spinlock_t fsl_lbc_lock = __SPIN_LOCK_UNLOCKED(fsl_lbc_lock);
struct fsl_lbc_ctrl *fsl_lbc_ctrl_dev;
EXPORT_SYMBOL(fsl_lbc_ctrl_dev);

/**
 * fsl_lbc_addr - convert the base address
 * @addr_base:  base address of the memory bank
 *
 * This function converts a base address of lbc into the right format for the
 * BR register. If the SOC has eLBC then it returns 32bit physical address
 * else it convers a 34bit local bus physical address to correct format of
 * 32bit address for BR register (Example: MPC8641).
 */
u32 fsl_lbc_addr(phys_addr_t addr_base)
{
        struct device_node *np = fsl_lbc_ctrl_dev->dev->of_node;
        u32 addr = addr_base & 0xffff8000;

        if (of_device_is_compatible(np, "fsl,elbc"))
                return addr;

        return addr | ((addr_base & 0x300000000ull) >> 19);
}
EXPORT_SYMBOL(fsl_lbc_addr);

/**
 * fsl_lbc_find - find Localbus bank
 * @addr_base:  base address of the memory bank
 *
 * This function walks LBC banks comparing "Base address" field of the BR
 * 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_lbc_find(phys_addr_t addr_base)
{
        int i;
        struct fsl_lbc_regs __iomem *lbc;

        if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
                return -ENODEV;

        lbc = fsl_lbc_ctrl_dev->regs;
        for (i = 0; i < ARRAY_SIZE(lbc->bank); i++) {
                u32 br = in_be32(&lbc->bank[i].br);
                u32 or = in_be32(&lbc->bank[i].or);

                if (br & BR_V && (br & or & BR_BA) == fsl_lbc_addr(addr_base))
                        return i;
        }

        return -ENOENT;
}
EXPORT_SYMBOL(fsl_lbc_find);

/**
 * fsl_upm_find - find pre-programmed UPM via base address
 * @addr_base:  base address of the memory bank controlled by the UPM
 * @upm:        pointer to the allocated fsl_upm structure
 *
 * This function fills fsl_upm structure so you can use it with the rest of
 * UPM API. On success this function returns 0, otherwise it returns
 * appropriate errno value.
 */
int fsl_upm_find(phys_addr_t addr_base, struct fsl_upm *upm)
{
        int bank;
        u32 br;
        struct fsl_lbc_regs __iomem *lbc;

        bank = fsl_lbc_find(addr_base);
        if (bank < 0)
                return bank;

        if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
                return -ENODEV;

        lbc = fsl_lbc_ctrl_dev->regs;
        br = in_be32(&lbc->bank[bank].br);

        switch (br & BR_MSEL) {
        case BR_MS_UPMA:
                upm->mxmr = &lbc->mamr;
                break;
        case BR_MS_UPMB:
                upm->mxmr = &lbc->mbmr;
                break;
        case BR_MS_UPMC:
                upm->mxmr = &lbc->mcmr;
                break;
        default:
                return -EINVAL;
        }

        switch (br & BR_PS) {
        case BR_PS_8:
                upm->width = 8;
                break;
        case BR_PS_16:
                upm->width = 16;
                break;
        case BR_PS_32:
                upm->width = 32;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}
EXPORT_SYMBOL(fsl_upm_find);

/**
 * fsl_upm_run_pattern - actually run an UPM pattern
 * @upm:        pointer to the fsl_upm structure obtained via fsl_upm_find
 * @io_base:    remapped pointer to where memory access should happen
 * @mar:        MAR register content during pattern execution
 *
 * This function triggers dummy write to the memory specified by the io_base,
 * thus UPM pattern actually executed. Note that mar usage depends on the
 * pre-programmed AMX bits in the UPM RAM.
 */
int fsl_upm_run_pattern(struct fsl_upm *upm, void __iomem *io_base, u32 mar)
{
        int ret = 0;
        unsigned long flags;

        if (!fsl_lbc_ctrl_dev || !fsl_lbc_ctrl_dev->regs)
                return -ENODEV;

        spin_lock_irqsave(&fsl_lbc_lock, flags);

        out_be32(&fsl_lbc_ctrl_dev->regs->mar, mar);

        switch (upm->width) {
        case 8:
                out_8(io_base, 0x0);
                break;
        case 16:
                out_be16(io_base, 0x0);
                break;
        case 32:
                out_be32(io_base, 0x0);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        spin_unlock_irqrestore(&fsl_lbc_lock, flags);

        return ret;
}
EXPORT_SYMBOL(fsl_upm_run_pattern);

static int fsl_lbc_ctrl_init(struct fsl_lbc_ctrl *ctrl,
                             struct device_node *node)
{
        struct fsl_lbc_regs __iomem *lbc = ctrl->regs;

        /* clear event registers */
        setbits32(&lbc->ltesr, LTESR_CLEAR);
        out_be32(&lbc->lteatr, 0);
        out_be32(&lbc->ltear, 0);
        out_be32(&lbc->lteccr, LTECCR_CLEAR);
        out_be32(&lbc->ltedr, LTEDR_ENABLE);

        /* Set the monitor timeout value to the maximum for erratum A001 */
        if (of_device_is_compatible(node, "fsl,elbc"))
                clrsetbits_be32(&lbc->lbcr, LBCR_BMT, LBCR_BMTPS);

        return 0;
}

/*
 * NOTE: This interrupt is used to report localbus events of various kinds,
 * such as transaction errors on the chipselects.
 */

static irqreturn_t fsl_lbc_ctrl_irq(int irqno, void *data)
{
        struct fsl_lbc_ctrl *ctrl = data;
        struct fsl_lbc_regs __iomem *lbc = ctrl->regs;
        u32 status;

        status = in_be32(&lbc->ltesr);
        if (!status)
                return IRQ_NONE;

        out_be32(&lbc->ltesr, LTESR_CLEAR);
        out_be32(&lbc->lteatr, 0);
        out_be32(&lbc->ltear, 0);
        ctrl->irq_status = status;

        if (status & LTESR_BM)
                dev_err(ctrl->dev, "Local bus monitor time-out: "
                        "LTESR 0x%08X\n", status);
        if (status & LTESR_WP)
                dev_err(ctrl->dev, "Write protect error: "
                        "LTESR 0x%08X\n", status);
        if (status & LTESR_ATMW)
                dev_err(ctrl->dev, "Atomic write error: "
                        "LTESR 0x%08X\n", status);
        if (status & LTESR_ATMR)
                dev_err(ctrl->dev, "Atomic read error: "
                        "LTESR 0x%08X\n", status);
        if (status & LTESR_CS)
                dev_err(ctrl->dev, "Chip select error: "
                        "LTESR 0x%08X\n", status);
        if (status & LTESR_UPM)
                ;
        if (status & LTESR_FCT) {
                dev_err(ctrl->dev, "FCM command time-out: "
                        "LTESR 0x%08X\n", status);
                smp_wmb();
                wake_up(&ctrl->irq_wait);
        }
        if (status & LTESR_PAR) {
                dev_err(ctrl->dev, "Parity or Uncorrectable ECC error: "
                        "LTESR 0x%08X\n", status);
                smp_wmb();
                wake_up(&ctrl->irq_wait);
        }
        if (status & LTESR_CC) {
                smp_wmb();
                wake_up(&ctrl->irq_wait);
        }
        if (status & ~LTESR_MASK)
                dev_err(ctrl->dev, "Unknown error: "
                        "LTESR 0x%08X\n", status);
        return IRQ_HANDLED;
}

/*
 * fsl_lbc_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_lbc_ctrl_probe(struct platform_device *dev)
{
        int ret;

        if (!dev->dev.of_node) {
                dev_err(&dev->dev, "Device OF-Node is NULL");
                return -EFAULT;
        }

        fsl_lbc_ctrl_dev = kzalloc(sizeof(*fsl_lbc_ctrl_dev), GFP_KERNEL);
        if (!fsl_lbc_ctrl_dev)
                return -ENOMEM;

        dev_set_drvdata(&dev->dev, fsl_lbc_ctrl_dev);

        spin_lock_init(&fsl_lbc_ctrl_dev->lock);
        init_waitqueue_head(&fsl_lbc_ctrl_dev->irq_wait);

        fsl_lbc_ctrl_dev->regs = of_iomap(dev->dev.of_node, 0);
        if (!fsl_lbc_ctrl_dev->regs) {
                dev_err(&dev->dev, "failed to get memory region\n");
                ret = -ENODEV;
                goto err;
        }

        fsl_lbc_ctrl_dev->irq = irq_of_parse_and_map(dev->dev.of_node, 0);
        if (fsl_lbc_ctrl_dev->irq == NO_IRQ) {
                dev_err(&dev->dev, "failed to get irq resource\n");
                ret = -ENODEV;
                goto err;
        }

        fsl_lbc_ctrl_dev->dev = &dev->dev;

        ret = fsl_lbc_ctrl_init(fsl_lbc_ctrl_dev, dev->dev.of_node);
        if (ret < 0)
                goto err;

        ret = request_irq(fsl_lbc_ctrl_dev->irq, fsl_lbc_ctrl_irq, 0,
                                "fsl-lbc", fsl_lbc_ctrl_dev);
        if (ret != 0) {
                dev_err(&dev->dev, "failed to install irq (%d)\n",
                        fsl_lbc_ctrl_dev->irq);
                ret = fsl_lbc_ctrl_dev->irq;
                goto err;
        }

        /* Enable interrupts for any detected events */
        out_be32(&fsl_lbc_ctrl_dev->regs->lteir, LTEIR_ENABLE);

        return 0;

err:
        iounmap(fsl_lbc_ctrl_dev->regs);
        kfree(fsl_lbc_ctrl_dev);
        fsl_lbc_ctrl_dev = NULL;
        return ret;
}

#ifdef CONFIG_SUSPEND

/* save lbc registers */
static int fsl_lbc_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct fsl_lbc_ctrl *ctrl = dev_get_drvdata(&pdev->dev);
        struct fsl_lbc_regs __iomem *lbc = ctrl->regs;

        ctrl->saved_regs = kmalloc(sizeof(struct fsl_lbc_regs), GFP_KERNEL);
        if (!ctrl->saved_regs)
                return -ENOMEM;

        _memcpy_fromio(ctrl->saved_regs, lbc, sizeof(struct fsl_lbc_regs));
        return 0;
}

/* restore lbc registers */
static int fsl_lbc_resume(struct platform_device *pdev)
{
        struct fsl_lbc_ctrl *ctrl = dev_get_drvdata(&pdev->dev);
        struct fsl_lbc_regs __iomem *lbc = ctrl->regs;

        if (ctrl->saved_regs) {
                _memcpy_toio(lbc, ctrl->saved_regs,
                                sizeof(struct fsl_lbc_regs));
                kfree(ctrl->saved_regs);
                ctrl->saved_regs = NULL;
        }
        return 0;
}
#endif /* CONFIG_SUSPEND */

static const struct of_device_id fsl_lbc_match[] = {
        { .compatible = "fsl,elbc", },
        { .compatible = "fsl,pq3-localbus", },
        { .compatible = "fsl,pq2-localbus", },
        { .compatible = "fsl,pq2pro-localbus", },
        {},
};

static struct platform_driver fsl_lbc_ctrl_driver = {
        .driver = {
                .name = "fsl-lbc",
                .of_match_table = fsl_lbc_match,
        },
        .probe = fsl_lbc_ctrl_probe,
#ifdef CONFIG_SUSPEND
        .suspend     = fsl_lbc_suspend,
        .resume      = fsl_lbc_resume,
#endif
};

static int __init fsl_lbc_init(void)
{
        return platform_driver_register(&fsl_lbc_ctrl_driver);
}
module_init(fsl_lbc_init);