/*
 * OMAP L3 Interconnect error handling driver
 *
 * Copyright (C) 2011-2015 Texas Instruments Incorporated - http://www.ti.com/
 *      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 version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include "omap_l3_noc.h"

/**
 * l3_handle_target() - Handle Target specific parse and reporting
 * @l3:         pointer to l3 struct
 * @base:       base address of clkdm
 * @flag_mux:   flagmux corresponding to the event
 * @err_src:    error source index of the slave (target)
 *
 * This does the second part of the error interrupt handling:
 *      3) Parse in the slave information
 *      4) Print the logged information.
 *      5) Add dump stack to provide kernel trace.
 *      6) Clear the source if known.
 *
 * This handles 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 int l3_handle_target(struct omap_l3 *l3, void __iomem *base,
                            struct l3_flagmux_data *flag_mux, int err_src)
{
        int k;
        u32 std_err_main, clear, masterid;
        u8 op_code, m_req_info;
        void __iomem *l3_targ_base;
        void __iomem *l3_targ_stderr, *l3_targ_slvofslsb, *l3_targ_mstaddr;
        void __iomem *l3_targ_hdr, *l3_targ_info;
        struct l3_target_data *l3_targ_inst;
        struct l3_masters_data *master;
        char *target_name, *master_name = "UN IDENTIFIED";
        char *err_description;
        char err_string[30] = { 0 };
        char info_string[60] = { 0 };

        /* We DONOT expect err_src to go out of bounds */
        BUG_ON(err_src > MAX_CLKDM_TARGETS);

        if (err_src < flag_mux->num_targ_data) {
                l3_targ_inst = &flag_mux->l3_targ[err_src];
                target_name = l3_targ_inst->name;
                l3_targ_base = base + l3_targ_inst->offset;
        } else {
                target_name = L3_TARGET_NOT_SUPPORTED;
        }

        if (target_name == L3_TARGET_NOT_SUPPORTED)
                return -ENODEV;

        /* Read the stderrlog_main_source from clk domain */
        l3_targ_stderr = l3_targ_base + L3_TARG_STDERRLOG_MAIN;
        l3_targ_slvofslsb = l3_targ_base + L3_TARG_STDERRLOG_SLVOFSLSB;

        std_err_main = readl_relaxed(l3_targ_stderr);

        switch (std_err_main & CUSTOM_ERROR) {
        case STANDARD_ERROR:
                err_description = "Standard";
                snprintf(err_string, sizeof(err_string),
                         ": At Address: 0x%08X ",
                         readl_relaxed(l3_targ_slvofslsb));

                l3_targ_mstaddr = l3_targ_base + L3_TARG_STDERRLOG_MSTADDR;
                l3_targ_hdr = l3_targ_base + L3_TARG_STDERRLOG_HDR;
                l3_targ_info = l3_targ_base + L3_TARG_STDERRLOG_INFO;
                break;

        case CUSTOM_ERROR:
                err_description = "Custom";

                l3_targ_mstaddr = l3_targ_base +
                                  L3_TARG_STDERRLOG_CINFO_MSTADDR;
                l3_targ_hdr = l3_targ_base + L3_TARG_STDERRLOG_CINFO_OPCODE;
                l3_targ_info = l3_targ_base + L3_TARG_STDERRLOG_CINFO_INFO;
                break;

        default:
                /* Nothing to be handled here as of now */
                return 0;
        }

        /* STDERRLOG_MSTADDR Stores the NTTP master address. */
        masterid = (readl_relaxed(l3_targ_mstaddr) &
                    l3->mst_addr_mask) >> __ffs(l3->mst_addr_mask);

        for (k = 0, master = l3->l3_masters; k < l3->num_masters;
             k++, master++) {
                if (masterid == master->id) {
                        master_name = master->name;
                        break;
                }
        }

        op_code = readl_relaxed(l3_targ_hdr) & 0x7;

        m_req_info = readl_relaxed(l3_targ_info) & 0xF;
        snprintf(info_string, sizeof(info_string),
                 ": %s in %s mode during %s access",
                 (m_req_info & BIT(0)) ? "Opcode Fetch" : "Data Access",
                 (m_req_info & BIT(1)) ? "Supervisor" : "User",
                 (m_req_info & BIT(3)) ? "Debug" : "Functional");

        WARN(true,
             "%s:L3 %s Error: MASTER %s TARGET %s (%s)%s%s\n",
             dev_name(l3->dev),
             err_description,
             master_name, target_name,
             l3_transaction_type[op_code],
             err_string, info_string);

        /* clear the std error log*/
        clear = std_err_main | CLEAR_STDERR_LOG;
        writel_relaxed(clear, l3_targ_stderr);

        return 0;
}

/**
 * l3_interrupt_handler() - interrupt handler for l3 events
 * @irq:        irq number
 * @_l3:        pointer to l3 structure
 *
 * 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
 *      ... handle the slave event..
 *      7) if the slave is unknown, mask out the slave.
 */
static irqreturn_t l3_interrupt_handler(int irq, void *_l3)
{
        struct omap_l3 *l3 = _l3;
        int inttype, i, ret;
        int err_src = 0;
        u32 err_reg, mask_val;
        void __iomem *base, *mask_reg;
        struct l3_flagmux_data *flag_mux;

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

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

                err_reg &= ~(inttype ? flag_mux->mask_app_bits :
                                flag_mux->mask_dbg_bits);

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

                        ret = l3_handle_target(l3, base, flag_mux, err_src);

                        /*
                         * Certain plaforms may have "undocumented" status
                         * pending on boot. So dont generate a severe warning
                         * here. Just mask it off to prevent the error from
                         * reoccuring and locking up the system.
                         */
                        if (ret) {
                                dev_err(l3->dev,
                                        "L3 %s error: target %d mod:%d %s\n",
                                        inttype ? "debug" : "application",
                                        err_src, i, "(unclearable)");

                                mask_reg = base + flag_mux->offset +
                                           L3_FLAGMUX_MASK0 + (inttype << 3);
                                mask_val = readl_relaxed(mask_reg);
                                mask_val &= ~(1 << err_src);
                                writel_relaxed(mask_val, mask_reg);

                                /* Mark these bits as to be ignored */
                                if (inttype)
                                        flag_mux->mask_app_bits |= 1 << err_src;
                                else
                                        flag_mux->mask_dbg_bits |= 1 << err_src;
                        }

                        /* Error found so break the for loop */
                        return IRQ_HANDLED;
                }
        }

        dev_err(l3->dev, "L3 %s IRQ not handled!!\n",
                inttype ? "debug" : "application");

        return IRQ_NONE;
}

static const struct of_device_id l3_noc_match[] = {
        {.compatible = "ti,omap4-l3-noc", .data = &omap4_l3_data},
        {.compatible = "ti,omap5-l3-noc", .data = &omap5_l3_data},
        {.compatible = "ti,dra7-l3-noc", .data = &dra_l3_data},
        {.compatible = "ti,am4372-l3-noc", .data = &am4372_l3_data},
        {},
};
MODULE_DEVICE_TABLE(of, l3_noc_match);

static int omap_l3_probe(struct platform_device *pdev)
{
        const struct of_device_id *of_id;
        static struct omap_l3 *l3;
        int ret, i, res_idx;

        of_id = of_match_device(l3_noc_match, &pdev->dev);
        if (!of_id) {
                dev_err(&pdev->dev, "OF data missing\n");
                return -EINVAL;
        }

        l3 = devm_kzalloc(&pdev->dev, sizeof(*l3), GFP_KERNEL);
        if (!l3)
                return -ENOMEM;

        memcpy(l3, of_id->data, sizeof(*l3));
        l3->dev = &pdev->dev;
        platform_set_drvdata(pdev, l3);

        /* Get mem resources */
        for (i = 0, res_idx = 0; i < l3->num_modules; i++) {
                struct resource *res;

                if (l3->l3_base[i] == L3_BASE_IS_SUBMODULE) {
                        /* First entry cannot be submodule */
                        BUG_ON(i == 0);
                        l3->l3_base[i] = l3->l3_base[i - 1];
                        continue;
                }
                res = platform_get_resource(pdev, IORESOURCE_MEM, res_idx);
                l3->l3_base[i] = devm_ioremap_resource(&pdev->dev, res);
                if (IS_ERR(l3->l3_base[i])) {
                        dev_err(l3->dev, "ioremap %d failed\n", i);
                        return PTR_ERR(l3->l3_base[i]);
                }
                res_idx++;
        }

        /*
         * Setup interrupt Handlers
         */
        l3->debug_irq = platform_get_irq(pdev, 0);
        ret = devm_request_irq(l3->dev, l3->debug_irq, l3_interrupt_handler,
                               0x0, "l3-dbg-irq", l3);
        if (ret) {
                dev_err(l3->dev, "request_irq failed for %d\n",
                        l3->debug_irq);
                return ret;
        }

        l3->app_irq = platform_get_irq(pdev, 1);
        ret = devm_request_irq(l3->dev, l3->app_irq, l3_interrupt_handler,
                               0x0, "l3-app-irq", l3);
        if (ret)
                dev_err(l3->dev, "request_irq failed for %d\n", l3->app_irq);

        return ret;
}

#ifdef  CONFIG_PM_SLEEP

/**
 * l3_resume_noirq() - resume function for l3_noc
 * @dev:        pointer to l3_noc device structure
 *
 * We only have the resume handler only since we
 * have already maintained the delta register
 * configuration as part of configuring the system
 */
static int l3_resume_noirq(struct device *dev)
{
        struct omap_l3 *l3 = dev_get_drvdata(dev);
        int i;
        struct l3_flagmux_data *flag_mux;
        void __iomem *base, *mask_regx = NULL;
        u32 mask_val;

        for (i = 0; i < l3->num_modules; i++) {
                base = l3->l3_base[i];
                flag_mux = l3->l3_flagmux[i];
                if (!flag_mux->mask_app_bits && !flag_mux->mask_dbg_bits)
                        continue;

                mask_regx = base + flag_mux->offset + L3_FLAGMUX_MASK0 +
                           (L3_APPLICATION_ERROR << 3);
                mask_val = readl_relaxed(mask_regx);
                mask_val &= ~(flag_mux->mask_app_bits);

                writel_relaxed(mask_val, mask_regx);
                mask_regx = base + flag_mux->offset + L3_FLAGMUX_MASK0 +
                           (L3_DEBUG_ERROR << 3);
                mask_val = readl_relaxed(mask_regx);
                mask_val &= ~(flag_mux->mask_dbg_bits);

                writel_relaxed(mask_val, mask_regx);
        }

        /* Dummy read to force OCP barrier */
        if (mask_regx)
                (void)readl(mask_regx);

        return 0;
}

static const struct dev_pm_ops l3_dev_pm_ops = {
        SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, l3_resume_noirq)
};

#define L3_DEV_PM_OPS (&l3_dev_pm_ops)
#else
#define L3_DEV_PM_OPS NULL
#endif

static struct platform_driver omap_l3_driver = {
        .probe          = omap_l3_probe,
        .driver         = {
                .name           = "omap_l3_noc",
                .pm             = L3_DEV_PM_OPS,
                .of_match_table = of_match_ptr(l3_noc_match),
        },
};

static int __init omap_l3_init(void)
{
        return platform_driver_register(&omap_l3_driver);
}
postcore_initcall_sync(omap_l3_init);

static void __exit omap_l3_exit(void)
{
        platform_driver_unregister(&omap_l3_driver);
}
module_exit(omap_l3_exit);

MODULE_AUTHOR("Santosh Shilimkar");
MODULE_AUTHOR("Sricharan R");
MODULE_DESCRIPTION("OMAP L3 Interconnect error handling driver");
MODULE_LICENSE("GPL v2");