// SPDX-License-Identifier: GPL-2.0-only
/*
 * TI K3 R5F (MCU) Remote Processor driver
 *
 * Copyright (C) 2017-2020 Texas Instruments Incorporated - https://www.ti.com/
 *      Suman Anna <s-anna@ti.com>
 */

#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_reserved_mem.h>
#include <linux/omap-mailbox.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/remoteproc.h>
#include <linux/reset.h>
#include <linux/slab.h>

#include "omap_remoteproc.h"
#include "remoteproc_internal.h"
#include "ti_sci_proc.h"

/* This address can either be for ATCM or BTCM with the other at address 0x0 */
#define K3_R5_TCM_DEV_ADDR      0x41010000

/* R5 TI-SCI Processor Configuration Flags */
#define PROC_BOOT_CFG_FLAG_R5_DBG_EN                    0x00000001
#define PROC_BOOT_CFG_FLAG_R5_DBG_NIDEN                 0x00000002
#define PROC_BOOT_CFG_FLAG_R5_LOCKSTEP                  0x00000100
#define PROC_BOOT_CFG_FLAG_R5_TEINIT                    0x00000200
#define PROC_BOOT_CFG_FLAG_R5_NMFI_EN                   0x00000400
#define PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE               0x00000800
#define PROC_BOOT_CFG_FLAG_R5_BTCM_EN                   0x00001000
#define PROC_BOOT_CFG_FLAG_R5_ATCM_EN                   0x00002000

/* R5 TI-SCI Processor Control Flags */
#define PROC_BOOT_CTRL_FLAG_R5_CORE_HALT                0x00000001

/* R5 TI-SCI Processor Status Flags */
#define PROC_BOOT_STATUS_FLAG_R5_WFE                    0x00000001
#define PROC_BOOT_STATUS_FLAG_R5_WFI                    0x00000002
#define PROC_BOOT_STATUS_FLAG_R5_CLK_GATED              0x00000004
#define PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED     0x00000100

/**
 * struct k3_r5_mem - internal memory structure
 * @cpu_addr: MPU virtual address of the memory region
 * @bus_addr: Bus address used to access the memory region
 * @dev_addr: Device address from remoteproc view
 * @size: Size of the memory region
 */
struct k3_r5_mem {
        void __iomem *cpu_addr;
        phys_addr_t bus_addr;
        u32 dev_addr;
        size_t size;
};

enum cluster_mode {
        CLUSTER_MODE_SPLIT = 0,
        CLUSTER_MODE_LOCKSTEP,
};

/**
 * struct k3_r5_cluster - K3 R5F Cluster structure
 * @dev: cached device pointer
 * @mode: Mode to configure the Cluster - Split or LockStep
 * @cores: list of R5 cores within the cluster
 */
struct k3_r5_cluster {
        struct device *dev;
        enum cluster_mode mode;
        struct list_head cores;
};

/**
 * struct k3_r5_core - K3 R5 core structure
 * @elem: linked list item
 * @dev: cached device pointer
 * @rproc: rproc handle representing this core
 * @mem: internal memory regions data
 * @sram: on-chip SRAM memory regions data
 * @num_mems: number of internal memory regions
 * @num_sram: number of on-chip SRAM memory regions
 * @reset: reset control handle
 * @tsp: TI-SCI processor control handle
 * @ti_sci: TI-SCI handle
 * @ti_sci_id: TI-SCI device identifier
 * @atcm_enable: flag to control ATCM enablement
 * @btcm_enable: flag to control BTCM enablement
 * @loczrama: flag to dictate which TCM is at device address 0x0
 */
struct k3_r5_core {
        struct list_head elem;
        struct device *dev;
        struct rproc *rproc;
        struct k3_r5_mem *mem;
        struct k3_r5_mem *sram;
        int num_mems;
        int num_sram;
        struct reset_control *reset;
        struct ti_sci_proc *tsp;
        const struct ti_sci_handle *ti_sci;
        u32 ti_sci_id;
        u32 atcm_enable;
        u32 btcm_enable;
        u32 loczrama;
};

/**
 * struct k3_r5_rproc - K3 remote processor state
 * @dev: cached device pointer
 * @cluster: cached pointer to parent cluster structure
 * @mbox: mailbox channel handle
 * @client: mailbox client to request the mailbox channel
 * @rproc: rproc handle
 * @core: cached pointer to r5 core structure being used
 * @rmem: reserved memory regions data
 * @num_rmems: number of reserved memory regions
 */
struct k3_r5_rproc {
        struct device *dev;
        struct k3_r5_cluster *cluster;
        struct mbox_chan *mbox;
        struct mbox_client client;
        struct rproc *rproc;
        struct k3_r5_core *core;
        struct k3_r5_mem *rmem;
        int num_rmems;
};

/**
 * k3_r5_rproc_mbox_callback() - inbound mailbox message handler
 * @client: mailbox client pointer used for requesting the mailbox channel
 * @data: mailbox payload
 *
 * This handler is invoked by the OMAP mailbox driver whenever a mailbox
 * message is received. Usually, the mailbox payload simply contains
 * the index of the virtqueue that is kicked by the remote processor,
 * and we let remoteproc core handle it.
 *
 * In addition to virtqueue indices, we also have some out-of-band values
 * that indicate different events. Those values are deliberately very
 * large so they don't coincide with virtqueue indices.
 */
static void k3_r5_rproc_mbox_callback(struct mbox_client *client, void *data)
{
        struct k3_r5_rproc *kproc = container_of(client, struct k3_r5_rproc,
                                                client);
        struct device *dev = kproc->rproc->dev.parent;
        const char *name = kproc->rproc->name;
        u32 msg = omap_mbox_message(data);

        dev_dbg(dev, "mbox msg: 0x%x\n", msg);

        switch (msg) {
        case RP_MBOX_CRASH:
                /*
                 * remoteproc detected an exception, but error recovery is not
                 * supported. So, just log this for now
                 */
                dev_err(dev, "K3 R5F rproc %s crashed\n", name);
                break;
        case RP_MBOX_ECHO_REPLY:
                dev_info(dev, "received echo reply from %s\n", name);
                break;
        default:
                /* silently handle all other valid messages */
                if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG)
                        return;
                if (msg > kproc->rproc->max_notifyid) {
                        dev_dbg(dev, "dropping unknown message 0x%x", msg);
                        return;
                }
                /* msg contains the index of the triggered vring */
                if (rproc_vq_interrupt(kproc->rproc, msg) == IRQ_NONE)
                        dev_dbg(dev, "no message was found in vqid %d\n", msg);
        }
}

/* kick a virtqueue */
static void k3_r5_rproc_kick(struct rproc *rproc, int vqid)
{
        struct k3_r5_rproc *kproc = rproc->priv;
        struct device *dev = rproc->dev.parent;
        mbox_msg_t msg = (mbox_msg_t)vqid;
        int ret;

        /* send the index of the triggered virtqueue in the mailbox payload */
        ret = mbox_send_message(kproc->mbox, (void *)msg);
        if (ret < 0)
                dev_err(dev, "failed to send mailbox message, status = %d\n",
                        ret);
}

static int k3_r5_split_reset(struct k3_r5_core *core)
{
        int ret;

        ret = reset_control_assert(core->reset);
        if (ret) {
                dev_err(core->dev, "local-reset assert failed, ret = %d\n",
                        ret);
                return ret;
        }

        ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
                                                   core->ti_sci_id);
        if (ret) {
                dev_err(core->dev, "module-reset assert failed, ret = %d\n",
                        ret);
                if (reset_control_deassert(core->reset))
                        dev_warn(core->dev, "local-reset deassert back failed\n");
        }

        return ret;
}

static int k3_r5_split_release(struct k3_r5_core *core)
{
        int ret;

        ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
                                                   core->ti_sci_id);
        if (ret) {
                dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
                        ret);
                return ret;
        }

        ret = reset_control_deassert(core->reset);
        if (ret) {
                dev_err(core->dev, "local-reset deassert failed, ret = %d\n",
                        ret);
                if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
                                                         core->ti_sci_id))
                        dev_warn(core->dev, "module-reset assert back failed\n");
        }

        return ret;
}

static int k3_r5_lockstep_reset(struct k3_r5_cluster *cluster)
{
        struct k3_r5_core *core;
        int ret;

        /* assert local reset on all applicable cores */
        list_for_each_entry(core, &cluster->cores, elem) {
                ret = reset_control_assert(core->reset);
                if (ret) {
                        dev_err(core->dev, "local-reset assert failed, ret = %d\n",
                                ret);
                        core = list_prev_entry(core, elem);
                        goto unroll_local_reset;
                }
        }

        /* disable PSC modules on all applicable cores */
        list_for_each_entry(core, &cluster->cores, elem) {
                ret = core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
                                                           core->ti_sci_id);
                if (ret) {
                        dev_err(core->dev, "module-reset assert failed, ret = %d\n",
                                ret);
                        goto unroll_module_reset;
                }
        }

        return 0;

unroll_module_reset:
        list_for_each_entry_continue_reverse(core, &cluster->cores, elem) {
                if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
                                                         core->ti_sci_id))
                        dev_warn(core->dev, "module-reset assert back failed\n");
        }
        core = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
unroll_local_reset:
        list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
                if (reset_control_deassert(core->reset))
                        dev_warn(core->dev, "local-reset deassert back failed\n");
        }

        return ret;
}

static int k3_r5_lockstep_release(struct k3_r5_cluster *cluster)
{
        struct k3_r5_core *core;
        int ret;

        /* enable PSC modules on all applicable cores */
        list_for_each_entry_reverse(core, &cluster->cores, elem) {
                ret = core->ti_sci->ops.dev_ops.get_device(core->ti_sci,
                                                           core->ti_sci_id);
                if (ret) {
                        dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
                                ret);
                        core = list_next_entry(core, elem);
                        goto unroll_module_reset;
                }
        }

        /* deassert local reset on all applicable cores */
        list_for_each_entry_reverse(core, &cluster->cores, elem) {
                ret = reset_control_deassert(core->reset);
                if (ret) {
                        dev_err(core->dev, "module-reset deassert failed, ret = %d\n",
                                ret);
                        goto unroll_local_reset;
                }
        }

        return 0;

unroll_local_reset:
        list_for_each_entry_continue(core, &cluster->cores, elem) {
                if (reset_control_assert(core->reset))
                        dev_warn(core->dev, "local-reset assert back failed\n");
        }
        core = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
unroll_module_reset:
        list_for_each_entry_from(core, &cluster->cores, elem) {
                if (core->ti_sci->ops.dev_ops.put_device(core->ti_sci,
                                                         core->ti_sci_id))
                        dev_warn(core->dev, "module-reset assert back failed\n");
        }

        return ret;
}

static inline int k3_r5_core_halt(struct k3_r5_core *core)
{
        return ti_sci_proc_set_control(core->tsp,
                                       PROC_BOOT_CTRL_FLAG_R5_CORE_HALT, 0);
}

static inline int k3_r5_core_run(struct k3_r5_core *core)
{
        return ti_sci_proc_set_control(core->tsp,
                                       0, PROC_BOOT_CTRL_FLAG_R5_CORE_HALT);
}

/*
 * The R5F cores have controls for both a reset and a halt/run. The code
 * execution from DDR requires the initial boot-strapping code to be run
 * from the internal TCMs. This function is used to release the resets on
 * applicable cores to allow loading into the TCMs. The .prepare() ops is
 * invoked by remoteproc core before any firmware loading, and is followed
 * by the .start() ops after loading to actually let the R5 cores run.
 */
static int k3_r5_rproc_prepare(struct rproc *rproc)
{
        struct k3_r5_rproc *kproc = rproc->priv;
        struct k3_r5_cluster *cluster = kproc->cluster;
        struct k3_r5_core *core = kproc->core;
        struct device *dev = kproc->dev;
        int ret;

        ret = (cluster->mode == CLUSTER_MODE_LOCKSTEP) ?
                k3_r5_lockstep_release(cluster) : k3_r5_split_release(core);
        if (ret) {
                dev_err(dev, "unable to enable cores for TCM loading, ret = %d\n",
                        ret);
                return ret;
        }

        /*
         * Zero out both TCMs unconditionally (access from v8 Arm core is not
         * affected by ATCM & BTCM enable configuration values) so that ECC
         * can be effective on all TCM addresses.
         */
        dev_dbg(dev, "zeroing out ATCM memory\n");
        memset(core->mem[0].cpu_addr, 0x00, core->mem[0].size);

        dev_dbg(dev, "zeroing out BTCM memory\n");
        memset(core->mem[1].cpu_addr, 0x00, core->mem[1].size);

        return 0;
}

/*
 * This function implements the .unprepare() ops and performs the complimentary
 * operations to that of the .prepare() ops. The function is used to assert the
 * resets on all applicable cores for the rproc device (depending on LockStep
 * or Split mode). This completes the second portion of powering down the R5F
 * cores. The cores themselves are only halted in the .stop() ops, and the
 * .unprepare() ops is invoked by the remoteproc core after the remoteproc is
 * stopped.
 */
static int k3_r5_rproc_unprepare(struct rproc *rproc)
{
        struct k3_r5_rproc *kproc = rproc->priv;
        struct k3_r5_cluster *cluster = kproc->cluster;
        struct k3_r5_core *core = kproc->core;
        struct device *dev = kproc->dev;
        int ret;

        ret = (cluster->mode == CLUSTER_MODE_LOCKSTEP) ?
                k3_r5_lockstep_reset(cluster) : k3_r5_split_reset(core);
        if (ret)
                dev_err(dev, "unable to disable cores, ret = %d\n", ret);

        return ret;
}

/*
 * The R5F start sequence includes two different operations
 * 1. Configure the boot vector for R5F core(s)
 * 2. Unhalt/Run the R5F core(s)
 *
 * The sequence is different between LockStep and Split modes. The LockStep
 * mode requires the boot vector to be configured only for Core0, and then
 * unhalt both the cores to start the execution - Core1 needs to be unhalted
 * first followed by Core0. The Split-mode requires that Core0 to be maintained
 * always in a higher power state that Core1 (implying Core1 needs to be started
 * always only after Core0 is started).
 */
static int k3_r5_rproc_start(struct rproc *rproc)
{
        struct k3_r5_rproc *kproc = rproc->priv;
        struct k3_r5_cluster *cluster = kproc->cluster;
        struct mbox_client *client = &kproc->client;
        struct device *dev = kproc->dev;
        struct k3_r5_core *core;
        u32 boot_addr;
        int ret;

        client->dev = dev;
        client->tx_done = NULL;
        client->rx_callback = k3_r5_rproc_mbox_callback;
        client->tx_block = false;
        client->knows_txdone = false;

        kproc->mbox = mbox_request_channel(client, 0);
        if (IS_ERR(kproc->mbox)) {
                ret = -EBUSY;
                dev_err(dev, "mbox_request_channel failed: %ld\n",
                        PTR_ERR(kproc->mbox));
                return ret;
        }

        /*
         * Ping the remote processor, this is only for sanity-sake for now;
         * there is no functional effect whatsoever.
         *
         * Note that the reply will _not_ arrive immediately: this message
         * will wait in the mailbox fifo until the remote processor is booted.
         */
        ret = mbox_send_message(kproc->mbox, (void *)RP_MBOX_ECHO_REQUEST);
        if (ret < 0) {
                dev_err(dev, "mbox_send_message failed: %d\n", ret);
                goto put_mbox;
        }

        boot_addr = rproc->bootaddr;
        /* TODO: add boot_addr sanity checking */
        dev_dbg(dev, "booting R5F core using boot addr = 0x%x\n", boot_addr);

        /* boot vector need not be programmed for Core1 in LockStep mode */
        core = kproc->core;
        ret = ti_sci_proc_set_config(core->tsp, boot_addr, 0, 0);
        if (ret)
                goto put_mbox;

        /* unhalt/run all applicable cores */
        if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
                list_for_each_entry_reverse(core, &cluster->cores, elem) {
                        ret = k3_r5_core_run(core);
                        if (ret)
                                goto unroll_core_run;
                }
        } else {
                ret = k3_r5_core_run(core);
                if (ret)
                        goto put_mbox;
        }

        return 0;

unroll_core_run:
        list_for_each_entry_continue(core, &cluster->cores, elem) {
                if (k3_r5_core_halt(core))
                        dev_warn(core->dev, "core halt back failed\n");
        }
put_mbox:
        mbox_free_channel(kproc->mbox);
        return ret;
}

/*
 * The R5F stop function includes the following operations
 * 1. Halt R5F core(s)
 *
 * The sequence is different between LockStep and Split modes, and the order
 * of cores the operations are performed are also in general reverse to that
 * of the start function. The LockStep mode requires each operation to be
 * performed first on Core0 followed by Core1. The Split-mode requires that
 * Core0 to be maintained always in a higher power state that Core1 (implying
 * Core1 needs to be stopped first before Core0).
 *
 * Note that the R5F halt operation in general is not effective when the R5F
 * core is running, but is needed to make sure the core won't run after
 * deasserting the reset the subsequent time. The asserting of reset can
 * be done here, but is preferred to be done in the .unprepare() ops - this
 * maintains the symmetric behavior between the .start(), .stop(), .prepare()
 * and .unprepare() ops, and also balances them well between sysfs 'state'
 * flow and device bind/unbind or module removal.
 */
static int k3_r5_rproc_stop(struct rproc *rproc)
{
        struct k3_r5_rproc *kproc = rproc->priv;
        struct k3_r5_cluster *cluster = kproc->cluster;
        struct k3_r5_core *core = kproc->core;
        int ret;

        /* halt all applicable cores */
        if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
                list_for_each_entry(core, &cluster->cores, elem) {
                        ret = k3_r5_core_halt(core);
                        if (ret) {
                                core = list_prev_entry(core, elem);
                                goto unroll_core_halt;
                        }
                }
        } else {
                ret = k3_r5_core_halt(core);
                if (ret)
                        goto out;
        }

        mbox_free_channel(kproc->mbox);

        return 0;

unroll_core_halt:
        list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
                if (k3_r5_core_run(core))
                        dev_warn(core->dev, "core run back failed\n");
        }
out:
        return ret;
}

/*
 * Internal Memory translation helper
 *
 * Custom function implementing the rproc .da_to_va ops to provide address
 * translation (device address to kernel virtual address) for internal RAMs
 * present in a DSP or IPU device). The translated addresses can be used
 * either by the remoteproc core for loading, or by any rpmsg bus drivers.
 */
static void *k3_r5_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len)
{
        struct k3_r5_rproc *kproc = rproc->priv;
        struct k3_r5_core *core = kproc->core;
        void __iomem *va = NULL;
        phys_addr_t bus_addr;
        u32 dev_addr, offset;
        size_t size;
        int i;

        if (len == 0)
                return NULL;

        /* handle both R5 and SoC views of ATCM and BTCM */
        for (i = 0; i < core->num_mems; i++) {
                bus_addr = core->mem[i].bus_addr;
                dev_addr = core->mem[i].dev_addr;
                size = core->mem[i].size;

                /* handle R5-view addresses of TCMs */
                if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
                        offset = da - dev_addr;
                        va = core->mem[i].cpu_addr + offset;
                        return (__force void *)va;
                }

                /* handle SoC-view addresses of TCMs */
                if (da >= bus_addr && ((da + len) <= (bus_addr + size))) {
                        offset = da - bus_addr;
                        va = core->mem[i].cpu_addr + offset;
                        return (__force void *)va;
                }
        }

        /* handle any SRAM regions using SoC-view addresses */
        for (i = 0; i < core->num_sram; i++) {
                dev_addr = core->sram[i].dev_addr;
                size = core->sram[i].size;

                if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
                        offset = da - dev_addr;
                        va = core->sram[i].cpu_addr + offset;
                        return (__force void *)va;
                }
        }

        /* handle static DDR reserved memory regions */
        for (i = 0; i < kproc->num_rmems; i++) {
                dev_addr = kproc->rmem[i].dev_addr;
                size = kproc->rmem[i].size;

                if (da >= dev_addr && ((da + len) <= (dev_addr + size))) {
                        offset = da - dev_addr;
                        va = kproc->rmem[i].cpu_addr + offset;
                        return (__force void *)va;
                }
        }

        return NULL;
}

static const struct rproc_ops k3_r5_rproc_ops = {
        .prepare        = k3_r5_rproc_prepare,
        .unprepare      = k3_r5_rproc_unprepare,
        .start          = k3_r5_rproc_start,
        .stop           = k3_r5_rproc_stop,
        .kick           = k3_r5_rproc_kick,
        .da_to_va       = k3_r5_rproc_da_to_va,
};

/*
 * Internal R5F Core configuration
 *
 * Each R5FSS has a cluster-level setting for configuring the processor
 * subsystem either in a safety/fault-tolerant LockStep mode or a performance
 * oriented Split mode. Each R5F core has a number of settings to either
 * enable/disable each of the TCMs, control which TCM appears at the R5F core's
 * address 0x0. These settings need to be configured before the resets for the
 * corresponding core are released. These settings are all protected and managed
 * by the System Processor.
 *
 * This function is used to pre-configure these settings for each R5F core, and
 * the configuration is all done through various ti_sci_proc functions that
 * communicate with the System Processor. The function also ensures that both
 * the cores are halted before the .prepare() step.
 *
 * The function is called from k3_r5_cluster_rproc_init() and is invoked either
 * once (in LockStep mode) or twice (in Split mode). Support for LockStep-mode
 * is dictated by an eFUSE register bit, and the config settings retrieved from
 * DT are adjusted accordingly as per the permitted cluster mode. All cluster
 * level settings like Cluster mode and TEINIT (exception handling state
 * dictating ARM or Thumb mode) can only be set and retrieved using Core0.
 *
 * The function behavior is different based on the cluster mode. The R5F cores
 * are configured independently as per their individual settings in Split mode.
 * They are identically configured in LockStep mode using the primary Core0
 * settings. However, some individual settings cannot be set in LockStep mode.
 * This is overcome by switching to Split-mode initially and then programming
 * both the cores with the same settings, before reconfiguing again for
 * LockStep mode.
 */
static int k3_r5_rproc_configure(struct k3_r5_rproc *kproc)
{
        struct k3_r5_cluster *cluster = kproc->cluster;
        struct device *dev = kproc->dev;
        struct k3_r5_core *core0, *core, *temp;
        u32 ctrl = 0, cfg = 0, stat = 0;
        u32 set_cfg = 0, clr_cfg = 0;
        u64 boot_vec = 0;
        bool lockstep_en;
        int ret;

        core0 = list_first_entry(&cluster->cores, struct k3_r5_core, elem);
        core = (cluster->mode == CLUSTER_MODE_LOCKSTEP) ? core0 : kproc->core;

        ret = ti_sci_proc_get_status(core->tsp, &boot_vec, &cfg, &ctrl,
                                     &stat);
        if (ret < 0)
                return ret;

        dev_dbg(dev, "boot_vector = 0x%llx, cfg = 0x%x ctrl = 0x%x stat = 0x%x\n",
                boot_vec, cfg, ctrl, stat);

        lockstep_en = !!(stat & PROC_BOOT_STATUS_FLAG_R5_LOCKSTEP_PERMITTED);
        if (!lockstep_en && cluster->mode == CLUSTER_MODE_LOCKSTEP) {
                dev_err(cluster->dev, "lockstep mode not permitted, force configuring for split-mode\n");
                cluster->mode = CLUSTER_MODE_SPLIT;
        }

        /* always enable ARM mode and set boot vector to 0 */
        boot_vec = 0x0;
        if (core == core0) {
                clr_cfg = PROC_BOOT_CFG_FLAG_R5_TEINIT;
                /*
                 * LockStep configuration bit is Read-only on Split-mode _only_
                 * devices and system firmware will NACK any requests with the
                 * bit configured, so program it only on permitted devices
                 */
                if (lockstep_en)
                        clr_cfg |= PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
        }

        if (core->atcm_enable)
                set_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;
        else
                clr_cfg |= PROC_BOOT_CFG_FLAG_R5_ATCM_EN;

        if (core->btcm_enable)
                set_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;
        else
                clr_cfg |= PROC_BOOT_CFG_FLAG_R5_BTCM_EN;

        if (core->loczrama)
                set_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;
        else
                clr_cfg |= PROC_BOOT_CFG_FLAG_R5_TCM_RSTBASE;

        if (cluster->mode == CLUSTER_MODE_LOCKSTEP) {
                /*
                 * work around system firmware limitations to make sure both
                 * cores are programmed symmetrically in LockStep. LockStep
                 * and TEINIT config is only allowed with Core0.
                 */
                list_for_each_entry(temp, &cluster->cores, elem) {
                        ret = k3_r5_core_halt(temp);
                        if (ret)
                                goto out;

                        if (temp != core) {
                                clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
                                clr_cfg &= ~PROC_BOOT_CFG_FLAG_R5_TEINIT;
                        }
                        ret = ti_sci_proc_set_config(temp->tsp, boot_vec,
                                                     set_cfg, clr_cfg);
                        if (ret)
                                goto out;
                }

                set_cfg = PROC_BOOT_CFG_FLAG_R5_LOCKSTEP;
                clr_cfg = 0;
                ret = ti_sci_proc_set_config(core->tsp, boot_vec,
                                             set_cfg, clr_cfg);
        } else {
                ret = k3_r5_core_halt(core);
                if (ret)
                        goto out;

                ret = ti_sci_proc_set_config(core->tsp, boot_vec,
                                             set_cfg, clr_cfg);
        }

out:
        return ret;
}

static int k3_r5_reserved_mem_init(struct k3_r5_rproc *kproc)
{
        struct device *dev = kproc->dev;
        struct device_node *np = dev_of_node(dev);
        struct device_node *rmem_np;
        struct reserved_mem *rmem;
        int num_rmems;
        int ret, i;

        num_rmems = of_property_count_elems_of_size(np, "memory-region",
                                                    sizeof(phandle));
        if (num_rmems <= 0) {
                dev_err(dev, "device does not have reserved memory regions, ret = %d\n",
                        num_rmems);
                return -EINVAL;
        }
        if (num_rmems < 2) {
                dev_err(dev, "device needs atleast two memory regions to be defined, num = %d\n",
                        num_rmems);
                return -EINVAL;
        }

        /* use reserved memory region 0 for vring DMA allocations */
        ret = of_reserved_mem_device_init_by_idx(dev, np, 0);
        if (ret) {
                dev_err(dev, "device cannot initialize DMA pool, ret = %d\n",
                        ret);
                return ret;
        }

        num_rmems--;
        kproc->rmem = kcalloc(num_rmems, sizeof(*kproc->rmem), GFP_KERNEL);
        if (!kproc->rmem) {
                ret = -ENOMEM;
                goto release_rmem;
        }

        /* use remaining reserved memory regions for static carveouts */
        for (i = 0; i < num_rmems; i++) {
                rmem_np = of_parse_phandle(np, "memory-region", i + 1);
                if (!rmem_np) {
                        ret = -EINVAL;
                        goto unmap_rmem;
                }

                rmem = of_reserved_mem_lookup(rmem_np);
                if (!rmem) {
                        of_node_put(rmem_np);
                        ret = -EINVAL;
                        goto unmap_rmem;
                }
                of_node_put(rmem_np);

                kproc->rmem[i].bus_addr = rmem->base;
                /*
                 * R5Fs do not have an MMU, but have a Region Address Translator
                 * (RAT) module that provides a fixed entry translation between
                 * the 32-bit processor addresses to 64-bit bus addresses. The
                 * RAT is programmable only by the R5F cores. Support for RAT
                 * is currently not supported, so 64-bit address regions are not
                 * supported. The absence of MMUs implies that the R5F device
                 * addresses/supported memory regions are restricted to 32-bit
                 * bus addresses, and are identical
                 */
                kproc->rmem[i].dev_addr = (u32)rmem->base;
                kproc->rmem[i].size = rmem->size;
                kproc->rmem[i].cpu_addr = ioremap_wc(rmem->base, rmem->size);
                if (!kproc->rmem[i].cpu_addr) {
                        dev_err(dev, "failed to map reserved memory#%d at %pa of size %pa\n",
                                i + 1, &rmem->base, &rmem->size);
                        ret = -ENOMEM;
                        goto unmap_rmem;
                }

                dev_dbg(dev, "reserved memory%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",
                        i + 1, &kproc->rmem[i].bus_addr,
                        kproc->rmem[i].size, kproc->rmem[i].cpu_addr,
                        kproc->rmem[i].dev_addr);
        }
        kproc->num_rmems = num_rmems;

        return 0;

unmap_rmem:
        for (i--; i >= 0; i--)
                iounmap(kproc->rmem[i].cpu_addr);
        kfree(kproc->rmem);
release_rmem:
        of_reserved_mem_device_release(dev);
        return ret;
}

static void k3_r5_reserved_mem_exit(struct k3_r5_rproc *kproc)
{
        int i;

        for (i = 0; i < kproc->num_rmems; i++)
                iounmap(kproc->rmem[i].cpu_addr);
        kfree(kproc->rmem);

        of_reserved_mem_device_release(kproc->dev);
}

static int k3_r5_cluster_rproc_init(struct platform_device *pdev)
{
        struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
        struct device *dev = &pdev->dev;
        struct k3_r5_rproc *kproc;
        struct k3_r5_core *core, *core1;
        struct device *cdev;
        const char *fw_name;
        struct rproc *rproc;
        int ret;

        core1 = list_last_entry(&cluster->cores, struct k3_r5_core, elem);
        list_for_each_entry(core, &cluster->cores, elem) {
                cdev = core->dev;
                ret = rproc_of_parse_firmware(cdev, 0, &fw_name);
                if (ret) {
                        dev_err(dev, "failed to parse firmware-name property, ret = %d\n",
                                ret);
                        goto out;
                }

                rproc = rproc_alloc(cdev, dev_name(cdev), &k3_r5_rproc_ops,
                                    fw_name, sizeof(*kproc));
                if (!rproc) {
                        ret = -ENOMEM;
                        goto out;
                }

                /* K3 R5s have a Region Address Translator (RAT) but no MMU */
                rproc->has_iommu = false;
                /* error recovery is not supported at present */
                rproc->recovery_disabled = true;

                kproc = rproc->priv;
                kproc->cluster = cluster;
                kproc->core = core;
                kproc->dev = cdev;
                kproc->rproc = rproc;
                core->rproc = rproc;

                ret = k3_r5_rproc_configure(kproc);
                if (ret) {
                        dev_err(dev, "initial configure failed, ret = %d\n",
                                ret);
                        goto err_config;
                }

                ret = k3_r5_reserved_mem_init(kproc);
                if (ret) {
                        dev_err(dev, "reserved memory init failed, ret = %d\n",
                                ret);
                        goto err_config;
                }

                ret = rproc_add(rproc);
                if (ret) {
                        dev_err(dev, "rproc_add failed, ret = %d\n", ret);
                        goto err_add;
                }

                /* create only one rproc in lockstep mode */
                if (cluster->mode == CLUSTER_MODE_LOCKSTEP)
                        break;
        }

        return 0;

err_split:
        rproc_del(rproc);
err_add:
        k3_r5_reserved_mem_exit(kproc);
err_config:
        rproc_free(rproc);
        core->rproc = NULL;
out:
        /* undo core0 upon any failures on core1 in split-mode */
        if (cluster->mode == CLUSTER_MODE_SPLIT && core == core1) {
                core = list_prev_entry(core, elem);
                rproc = core->rproc;
                kproc = rproc->priv;
                goto err_split;
        }
        return ret;
}

static int k3_r5_cluster_rproc_exit(struct platform_device *pdev)
{
        struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
        struct k3_r5_rproc *kproc;
        struct k3_r5_core *core;
        struct rproc *rproc;

        /*
         * lockstep mode has only one rproc associated with first core, whereas
         * split-mode has two rprocs associated with each core, and requires
         * that core1 be powered down first
         */
        core = (cluster->mode == CLUSTER_MODE_LOCKSTEP) ?
                list_first_entry(&cluster->cores, struct k3_r5_core, elem) :
                list_last_entry(&cluster->cores, struct k3_r5_core, elem);

        list_for_each_entry_from_reverse(core, &cluster->cores, elem) {
                rproc = core->rproc;
                kproc = rproc->priv;

                rproc_del(rproc);

                k3_r5_reserved_mem_exit(kproc);

                rproc_free(rproc);
                core->rproc = NULL;
        }

        return 0;
}

static int k3_r5_core_of_get_internal_memories(struct platform_device *pdev,
                                               struct k3_r5_core *core)
{
        static const char * const mem_names[] = {"atcm", "btcm"};
        struct device *dev = &pdev->dev;
        struct resource *res;
        int num_mems;
        int i;

        num_mems = ARRAY_SIZE(mem_names);
        core->mem = devm_kcalloc(dev, num_mems, sizeof(*core->mem), GFP_KERNEL);
        if (!core->mem)
                return -ENOMEM;

        for (i = 0; i < num_mems; i++) {
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                                   mem_names[i]);
                if (!res) {
                        dev_err(dev, "found no memory resource for %s\n",
                                mem_names[i]);
                        return -EINVAL;
                }
                if (!devm_request_mem_region(dev, res->start,
                                             resource_size(res),
                                             dev_name(dev))) {
                        dev_err(dev, "could not request %s region for resource\n",
                                mem_names[i]);

                        return -EBUSY;
                }

                /*
                 * TCMs are designed in general to support RAM-like backing
                 * memories. So, map these as Normal Non-Cached memories. This
                 * also avoids/fixes any potential alignment faults due to
                 * unaligned data accesses when using memcpy() or memset()
                 * functions (normally seen with device type memory).
                 */
                core->mem[i].cpu_addr = devm_ioremap_wc(dev, res->start,
                                                        resource_size(res));
                if (!core->mem[i].cpu_addr) {
                        dev_err(dev, "failed to map %s memory\n", mem_names[i]);
                        return -ENOMEM;
                }
                core->mem[i].bus_addr = res->start;

                /*
                 * TODO:
                 * The R5F cores can place ATCM & BTCM anywhere in its address
                 * based on the corresponding Region Registers in the System
                 * Control coprocessor. For now, place ATCM and BTCM at
                 * addresses 0 and 0x41010000 (same as the bus address on AM65x
                 * SoCs) based on loczrama setting
                 */
                if (!strcmp(mem_names[i], "atcm")) {
                        core->mem[i].dev_addr = core->loczrama ?
                                                        0 : K3_R5_TCM_DEV_ADDR;
                } else {
                        core->mem[i].dev_addr = core->loczrama ?
                                                        K3_R5_TCM_DEV_ADDR : 0;
                }
                core->mem[i].size = resource_size(res);

                dev_dbg(dev, "memory %5s: bus addr %pa size 0x%zx va %pK da 0x%x\n",
                        mem_names[i], &core->mem[i].bus_addr,
                        core->mem[i].size, core->mem[i].cpu_addr,
                        core->mem[i].dev_addr);
        }
        core->num_mems = num_mems;

        return 0;
}

static int k3_r5_core_of_get_sram_memories(struct platform_device *pdev,
                                           struct k3_r5_core *core)
{
        struct device_node *np = pdev->dev.of_node;
        struct device *dev = &pdev->dev;
        struct device_node *sram_np;
        struct resource res;
        int num_sram;
        int i, ret;

        num_sram = of_property_count_elems_of_size(np, "sram", sizeof(phandle));
        if (num_sram <= 0) {
                dev_dbg(dev, "device does not use reserved on-chip memories, num_sram = %d\n",
                        num_sram);
                return 0;
        }

        core->sram = devm_kcalloc(dev, num_sram, sizeof(*core->sram), GFP_KERNEL);
        if (!core->sram)
                return -ENOMEM;

        for (i = 0; i < num_sram; i++) {
                sram_np = of_parse_phandle(np, "sram", i);
                if (!sram_np)
                        return -EINVAL;

                if (!of_device_is_available(sram_np)) {
                        of_node_put(sram_np);
                        return -EINVAL;
                }

                ret = of_address_to_resource(sram_np, 0, &res);
                of_node_put(sram_np);
                if (ret)
                        return -EINVAL;

                core->sram[i].bus_addr = res.start;
                core->sram[i].dev_addr = res.start;
                core->sram[i].size = resource_size(&res);
                core->sram[i].cpu_addr = devm_ioremap_wc(dev, res.start,
                                                         resource_size(&res));
                if (!core->sram[i].cpu_addr) {
                        dev_err(dev, "failed to parse and map sram%d memory at %pad\n",
                                i, &res.start);
                        return -ENOMEM;
                }

                dev_dbg(dev, "memory sram%d: bus addr %pa size 0x%zx va %pK da 0x%x\n",
                        i, &core->sram[i].bus_addr,
                        core->sram[i].size, core->sram[i].cpu_addr,
                        core->sram[i].dev_addr);
        }
        core->num_sram = num_sram;

        return 0;
}

static
struct ti_sci_proc *k3_r5_core_of_get_tsp(struct device *dev,
                                          const struct ti_sci_handle *sci)
{
        struct ti_sci_proc *tsp;
        u32 temp[2];
        int ret;

        ret = of_property_read_u32_array(dev_of_node(dev), "ti,sci-proc-ids",
                                         temp, 2);
        if (ret < 0)
                return ERR_PTR(ret);

        tsp = devm_kzalloc(dev, sizeof(*tsp), GFP_KERNEL);
        if (!tsp)
                return ERR_PTR(-ENOMEM);

        tsp->dev = dev;
        tsp->sci = sci;
        tsp->ops = &sci->ops.proc_ops;
        tsp->proc_id = temp[0];
        tsp->host_id = temp[1];

        return tsp;
}

static int k3_r5_core_of_init(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np = dev_of_node(dev);
        struct k3_r5_core *core;
        int ret;

        if (!devres_open_group(dev, k3_r5_core_of_init, GFP_KERNEL))
                return -ENOMEM;

        core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
        if (!core) {
                ret = -ENOMEM;
                goto err;
        }

        core->dev = dev;
        /*
         * Use SoC Power-on-Reset values as default if no DT properties are
         * used to dictate the TCM configurations
         */
        core->atcm_enable = 0;
        core->btcm_enable = 1;
        core->loczrama = 1;

        ret = of_property_read_u32(np, "ti,atcm-enable", &core->atcm_enable);
        if (ret < 0 && ret != -EINVAL) {
                dev_err(dev, "invalid format for ti,atcm-enable, ret = %d\n",
                        ret);
                goto err;
        }

        ret = of_property_read_u32(np, "ti,btcm-enable", &core->btcm_enable);
        if (ret < 0 && ret != -EINVAL) {
                dev_err(dev, "invalid format for ti,btcm-enable, ret = %d\n",
                        ret);
                goto err;
        }

        ret = of_property_read_u32(np, "ti,loczrama", &core->loczrama);
        if (ret < 0 && ret != -EINVAL) {
                dev_err(dev, "invalid format for ti,loczrama, ret = %d\n", ret);
                goto err;
        }

        core->ti_sci = devm_ti_sci_get_by_phandle(dev, "ti,sci");
        if (IS_ERR(core->ti_sci)) {
                ret = PTR_ERR(core->ti_sci);
                if (ret != -EPROBE_DEFER) {
                        dev_err(dev, "failed to get ti-sci handle, ret = %d\n",
                                ret);
                }
                core->ti_sci = NULL;
                goto err;
        }

        ret = of_property_read_u32(np, "ti,sci-dev-id", &core->ti_sci_id);
        if (ret) {
                dev_err(dev, "missing 'ti,sci-dev-id' property\n");
                goto err;
        }

        core->reset = devm_reset_control_get_exclusive(dev, NULL);
        if (IS_ERR_OR_NULL(core->reset)) {
                ret = PTR_ERR_OR_ZERO(core->reset);
                if (!ret)
                        ret = -ENODEV;
                if (ret != -EPROBE_DEFER) {
                        dev_err(dev, "failed to get reset handle, ret = %d\n",
                                ret);
                }
                goto err;
        }

        core->tsp = k3_r5_core_of_get_tsp(dev, core->ti_sci);
        if (IS_ERR(core->tsp)) {
                dev_err(dev, "failed to construct ti-sci proc control, ret = %d\n",
                        ret);
                ret = PTR_ERR(core->tsp);
                goto err;
        }

        ret = k3_r5_core_of_get_internal_memories(pdev, core);
        if (ret) {
                dev_err(dev, "failed to get internal memories, ret = %d\n",
                        ret);
                goto err;
        }

        ret = k3_r5_core_of_get_sram_memories(pdev, core);
        if (ret) {
                dev_err(dev, "failed to get sram memories, ret = %d\n", ret);
                goto err;
        }

        ret = ti_sci_proc_request(core->tsp);
        if (ret < 0) {
                dev_err(dev, "ti_sci_proc_request failed, ret = %d\n", ret);
                goto err;
        }

        platform_set_drvdata(pdev, core);
        devres_close_group(dev, k3_r5_core_of_init);

        return 0;

err:
        devres_release_group(dev, k3_r5_core_of_init);
        return ret;
}

/*
 * free the resources explicitly since driver model is not being used
 * for the child R5F devices
 */
static void k3_r5_core_of_exit(struct platform_device *pdev)
{
        struct k3_r5_core *core = platform_get_drvdata(pdev);
        struct device *dev = &pdev->dev;
        int ret;

        ret = ti_sci_proc_release(core->tsp);
        if (ret)
                dev_err(dev, "failed to release proc, ret = %d\n", ret);

        platform_set_drvdata(pdev, NULL);
        devres_release_group(dev, k3_r5_core_of_init);
}

static void k3_r5_cluster_of_exit(struct platform_device *pdev)
{
        struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
        struct platform_device *cpdev;
        struct k3_r5_core *core, *temp;

        list_for_each_entry_safe_reverse(core, temp, &cluster->cores, elem) {
                list_del(&core->elem);
                cpdev = to_platform_device(core->dev);
                k3_r5_core_of_exit(cpdev);
        }
}

static int k3_r5_cluster_of_init(struct platform_device *pdev)
{
        struct k3_r5_cluster *cluster = platform_get_drvdata(pdev);
        struct device *dev = &pdev->dev;
        struct device_node *np = dev_of_node(dev);
        struct platform_device *cpdev;
        struct device_node *child;
        struct k3_r5_core *core;
        int ret;

        for_each_available_child_of_node(np, child) {
                cpdev = of_find_device_by_node(child);
                if (!cpdev) {
                        ret = -ENODEV;
                        dev_err(dev, "could not get R5 core platform device\n");
                        goto fail;
                }

                ret = k3_r5_core_of_init(cpdev);
                if (ret) {
                        dev_err(dev, "k3_r5_core_of_init failed, ret = %d\n",
                                ret);
                        put_device(&cpdev->dev);
                        goto fail;
                }

                core = platform_get_drvdata(cpdev);
                put_device(&cpdev->dev);
                list_add_tail(&core->elem, &cluster->cores);
        }

        return 0;

fail:
        k3_r5_cluster_of_exit(pdev);
        return ret;
}

static int k3_r5_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np = dev_of_node(dev);
        struct k3_r5_cluster *cluster;
        int ret;
        int num_cores;

        cluster = devm_kzalloc(dev, sizeof(*cluster), GFP_KERNEL);
        if (!cluster)
                return -ENOMEM;

        cluster->dev = dev;
        cluster->mode = CLUSTER_MODE_LOCKSTEP;
        INIT_LIST_HEAD(&cluster->cores);

        ret = of_property_read_u32(np, "ti,cluster-mode", &cluster->mode);
        if (ret < 0 && ret != -EINVAL) {
                dev_err(dev, "invalid format for ti,cluster-mode, ret = %d\n",
                        ret);
                return ret;
        }

        num_cores = of_get_available_child_count(np);
        if (num_cores != 2) {
                dev_err(dev, "MCU cluster requires both R5F cores to be enabled, num_cores = %d\n",
                        num_cores);
                return -ENODEV;
        }

        platform_set_drvdata(pdev, cluster);

        ret = devm_of_platform_populate(dev);
        if (ret) {
                dev_err(dev, "devm_of_platform_populate failed, ret = %d\n",
                        ret);
                return ret;
        }

        ret = k3_r5_cluster_of_init(pdev);
        if (ret) {
                dev_err(dev, "k3_r5_cluster_of_init failed, ret = %d\n", ret);
                return ret;
        }

        ret = devm_add_action_or_reset(dev,
                                       (void(*)(void *))k3_r5_cluster_of_exit,
                                       pdev);
        if (ret)
                return ret;

        ret = k3_r5_cluster_rproc_init(pdev);
        if (ret) {
                dev_err(dev, "k3_r5_cluster_rproc_init failed, ret = %d\n",
                        ret);
                return ret;
        }

        ret = devm_add_action_or_reset(dev,
                                       (void(*)(void *))k3_r5_cluster_rproc_exit,
                                       pdev);
        if (ret)
                return ret;

        return 0;
}

static const struct of_device_id k3_r5_of_match[] = {
        { .compatible = "ti,am654-r5fss", },
        { .compatible = "ti,j721e-r5fss", },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, k3_r5_of_match);

static struct platform_driver k3_r5_rproc_driver = {
        .probe = k3_r5_probe,
        .driver = {
                .name = "k3_r5_rproc",
                .of_match_table = k3_r5_of_match,
        },
};

module_platform_driver(k3_r5_rproc_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TI K3 R5F remote processor driver");
MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");