/*
 * OMAP4XXX L3 Interconnect error handling driver
 *
 * Copyright (C) 2011 Texas Corporation
 *      Santosh Shilimkar <santosh.shilimkar@ti.com>
 *      Sricharan <r.sricharan@ti.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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/slab.h>

#include "omap_l3_noc.h"

/*
 * Interrupt Handler for L3 error detection.
 *      1) Identify the L3 clockdomain partition to which the error belongs to.
 *      2) Identify the slave where the error information is logged
 *      3) Print the logged information.
 *      4) Add dump stack to provide kernel trace.
 *
 * Two Types of errors :
 *      1) Custom errors in L3 :
 *              Target like DMM/FW/EMIF generates SRESP=ERR error
 *      2) Standard L3 error:
 *              - Unsupported CMD.
 *                      L3 tries to access target while it is idle
 *              - OCP disconnect.
 *              - Address hole error:
 *                      If DSS/ISS/FDIF/USBHOSTFS access a target where they
 *                      do not have connectivity, the error is logged in
 *                      their default target which is DMM2.
 *
 *      On High Secure devices, firewall errors are possible and those
 *      can be trapped as well. But the trapping is implemented as part
 *      secure software and hence need not be implemented here.
 */
static irqreturn_t l3_interrupt_handler(int irq, void *_l3)
{

        struct omap4_l3 *l3 = _l3;
        int inttype, i, k;
        int err_src = 0;
        u32 std_err_main, err_reg, clear, masterid;
        void __iomem *base, *l3_targ_base;
        char *target_name, *master_name = "UN IDENTIFIED";

        /* Get the Type of interrupt */
        inttype = irq == l3->app_irq ? L3_APPLICATION_ERROR : L3_DEBUG_ERROR;

        for (i = 0; i < L3_MODULES; i++) {
                /*
                 * Read the regerr register of the clock domain
                 * to determine the source
                 */
                base = l3->l3_base[i];
                err_reg = __raw_readl(base + l3_flagmux[i] +
                                        + L3_FLAGMUX_REGERR0 + (inttype << 3));

                /* Get the corresponding error and analyse */
                if (err_reg) {
                        /* Identify the source from control status register */
                        err_src = __ffs(err_reg);

                        /* Read the stderrlog_main_source from clk domain */
                        l3_targ_base = base + *(l3_targ[i] + err_src);
                        std_err_main =  __raw_readl(l3_targ_base +
                                        L3_TARG_STDERRLOG_MAIN);
                        masterid = __raw_readl(l3_targ_base +
                                        L3_TARG_STDERRLOG_MSTADDR);

                        switch (std_err_main & CUSTOM_ERROR) {
                        case STANDARD_ERROR:
                                target_name =
                                        l3_targ_inst_name[i][err_src];
                                WARN(true, "L3 standard error: TARGET:%s at address 0x%x\n",
                                        target_name,
                                        __raw_readl(l3_targ_base +
                                                L3_TARG_STDERRLOG_SLVOFSLSB));
                                /* clear the std error log*/
                                clear = std_err_main | CLEAR_STDERR_LOG;
                                writel(clear, l3_targ_base +
                                        L3_TARG_STDERRLOG_MAIN);
                                break;

                        case CUSTOM_ERROR:
                                target_name =
                                        l3_targ_inst_name[i][err_src];
                                for (k = 0; k < NUM_OF_L3_MASTERS; k++) {
                                        if (masterid == l3_masters[k].id)
                                                master_name =
                                                        l3_masters[k].name;
                                }
                                WARN(true, "L3 custom error: MASTER:%s TARGET:%s\n",
                                        master_name, target_name);
                                /* clear the std error log*/
                                clear = std_err_main | CLEAR_STDERR_LOG;
                                writel(clear, l3_targ_base +
                                        L3_TARG_STDERRLOG_MAIN);
                                break;

                        default:
                                /* Nothing to be handled here as of now */
                                break;
                        }
                /* Error found so break the for loop */
                break;
                }
        }
        return IRQ_HANDLED;
}

static int omap4_l3_probe(struct platform_device *pdev)
{
        static struct omap4_l3 *l3;
        struct resource *res;
        int ret;

        l3 = kzalloc(sizeof(*l3), GFP_KERNEL);
        if (!l3)
                return -ENOMEM;

        platform_set_drvdata(pdev, l3);
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res) {
                dev_err(&pdev->dev, "couldn't find resource 0\n");
                ret = -ENODEV;
                goto err0;
        }

        l3->l3_base[0] = ioremap(res->start, resource_size(res));
        if (!l3->l3_base[0]) {
                dev_err(&pdev->dev, "ioremap failed\n");
                ret = -ENOMEM;
                goto err0;
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        if (!res) {
                dev_err(&pdev->dev, "couldn't find resource 1\n");
                ret = -ENODEV;
                goto err1;
        }

        l3->l3_base[1] = ioremap(res->start, resource_size(res));
        if (!l3->l3_base[1]) {
                dev_err(&pdev->dev, "ioremap failed\n");
                ret = -ENOMEM;
                goto err1;
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
        if (!res) {
                dev_err(&pdev->dev, "couldn't find resource 2\n");
                ret = -ENODEV;
                goto err2;
        }

        l3->l3_base[2] = ioremap(res->start, resource_size(res));
        if (!l3->l3_base[2]) {
                dev_err(&pdev->dev, "ioremap failed\n");
                ret = -ENOMEM;
                goto err2;
        }

        /*
         * Setup interrupt Handlers
         */
        l3->debug_irq = platform_get_irq(pdev, 0);
        ret = request_irq(l3->debug_irq,
                        l3_interrupt_handler,
                        IRQF_DISABLED, "l3-dbg-irq", l3);
        if (ret) {
                pr_crit("L3: request_irq failed to register for 0x%x\n",
                                                l3->debug_irq);
                goto err3;
        }

        l3->app_irq = platform_get_irq(pdev, 1);
        ret = request_irq(l3->app_irq,
                        l3_interrupt_handler,
                        IRQF_DISABLED, "l3-app-irq", l3);
        if (ret) {
                pr_crit("L3: request_irq failed to register for 0x%x\n",
                                                l3->app_irq);
                goto err4;
        }

        return 0;

err4:
        free_irq(l3->debug_irq, l3);
err3:
        iounmap(l3->l3_base[2]);
err2:
        iounmap(l3->l3_base[1]);
err1:
        iounmap(l3->l3_base[0]);
err0:
        kfree(l3);
        return ret;
}

static int omap4_l3_remove(struct platform_device *pdev)
{
        struct omap4_l3 *l3 = platform_get_drvdata(pdev);

        free_irq(l3->app_irq, l3);
        free_irq(l3->debug_irq, l3);
        iounmap(l3->l3_base[0]);
        iounmap(l3->l3_base[1]);
        iounmap(l3->l3_base[2]);
        kfree(l3);

        return 0;
}

#if defined(CONFIG_OF)
static const struct of_device_id l3_noc_match[] = {
        {.compatible = "ti,omap4-l3-noc", },
        {},
};
MODULE_DEVICE_TABLE(of, l3_noc_match);
#else
#define l3_noc_match NULL
#endif

static struct platform_driver omap4_l3_driver = {
        .probe          = omap4_l3_probe,
        .remove         = omap4_l3_remove,
        .driver         = {
                .name           = "omap_l3_noc",
                .owner          = THIS_MODULE,
                .of_match_table = l3_noc_match,
        },
};

static int __init omap4_l3_init(void)
{
        return platform_driver_register(&omap4_l3_driver);
}
postcore_initcall_sync(omap4_l3_init);

static void __exit omap4_l3_exit(void)
{
        platform_driver_unregister(&omap4_l3_driver);
}
module_exit(omap4_l3_exit);