// SPDX-License-Identifier: GPL-2.0-only
/*
 * PRU-ICSS remoteproc driver for various TI SoCs
 *
 * Copyright (C) 2014-2020 Texas Instruments Incorporated - https://www.ti.com/
 *
 * Author(s):
 *      Suman Anna <s-anna@ti.com>
 *      Andrew F. Davis <afd@ti.com>
 *      Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> for Texas Instruments
 */

#include <linux/bitops.h>
#include <linux/debugfs.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/pruss_driver.h>
#include <linux/remoteproc.h>

#include "remoteproc_internal.h"
#include "remoteproc_elf_helpers.h"
#include "pru_rproc.h"

/* PRU_ICSS_PRU_CTRL registers */
#define PRU_CTRL_CTRL           0x0000
#define PRU_CTRL_STS            0x0004
#define PRU_CTRL_WAKEUP_EN      0x0008
#define PRU_CTRL_CYCLE          0x000C
#define PRU_CTRL_STALL          0x0010
#define PRU_CTRL_CTBIR0         0x0020
#define PRU_CTRL_CTBIR1         0x0024
#define PRU_CTRL_CTPPR0         0x0028
#define PRU_CTRL_CTPPR1         0x002C

/* CTRL register bit-fields */
#define CTRL_CTRL_SOFT_RST_N    BIT(0)
#define CTRL_CTRL_EN            BIT(1)
#define CTRL_CTRL_SLEEPING      BIT(2)
#define CTRL_CTRL_CTR_EN        BIT(3)
#define CTRL_CTRL_SINGLE_STEP   BIT(8)
#define CTRL_CTRL_RUNSTATE      BIT(15)

/* PRU_ICSS_PRU_DEBUG registers */
#define PRU_DEBUG_GPREG(x)      (0x0000 + (x) * 4)
#define PRU_DEBUG_CT_REG(x)     (0x0080 + (x) * 4)

/* PRU/RTU/Tx_PRU Core IRAM address masks */
#define PRU_IRAM_ADDR_MASK      0x3ffff
#define PRU0_IRAM_ADDR_MASK     0x34000
#define PRU1_IRAM_ADDR_MASK     0x38000
#define RTU0_IRAM_ADDR_MASK     0x4000
#define RTU1_IRAM_ADDR_MASK     0x6000
#define TX_PRU0_IRAM_ADDR_MASK  0xa000
#define TX_PRU1_IRAM_ADDR_MASK  0xc000

/* PRU device addresses for various type of PRU RAMs */
#define PRU_IRAM_DA     0       /* Instruction RAM */
#define PRU_PDRAM_DA    0       /* Primary Data RAM */
#define PRU_SDRAM_DA    0x2000  /* Secondary Data RAM */
#define PRU_SHRDRAM_DA  0x10000 /* Shared Data RAM */

#define MAX_PRU_SYS_EVENTS 160

/**
 * enum pru_iomem - PRU core memory/register range identifiers
 *
 * @PRU_IOMEM_IRAM: PRU Instruction RAM range
 * @PRU_IOMEM_CTRL: PRU Control register range
 * @PRU_IOMEM_DEBUG: PRU Debug register range
 * @PRU_IOMEM_MAX: just keep this one at the end
 */
enum pru_iomem {
        PRU_IOMEM_IRAM = 0,
        PRU_IOMEM_CTRL,
        PRU_IOMEM_DEBUG,
        PRU_IOMEM_MAX,
};

/**
 * enum pru_type - PRU core type identifier
 *
 * @PRU_TYPE_PRU: Programmable Real-time Unit
 * @PRU_TYPE_RTU: Auxiliary Programmable Real-Time Unit
 * @PRU_TYPE_TX_PRU: Transmit Programmable Real-Time Unit
 * @PRU_TYPE_MAX: just keep this one at the end
 */
enum pru_type {
        PRU_TYPE_PRU = 0,
        PRU_TYPE_RTU,
        PRU_TYPE_TX_PRU,
        PRU_TYPE_MAX,
};

/**
 * struct pru_private_data - device data for a PRU core
 * @type: type of the PRU core (PRU, RTU, Tx_PRU)
 * @is_k3: flag used to identify the need for special load handling
 */
struct pru_private_data {
        enum pru_type type;
        unsigned int is_k3 : 1;
};

/**
 * struct pru_rproc - PRU remoteproc structure
 * @id: id of the PRU core within the PRUSS
 * @dev: PRU core device pointer
 * @pruss: back-reference to parent PRUSS structure
 * @rproc: remoteproc pointer for this PRU core
 * @data: PRU core specific data
 * @mem_regions: data for each of the PRU memory regions
 * @fw_name: name of firmware image used during loading
 * @mapped_irq: virtual interrupt numbers of created fw specific mapping
 * @pru_interrupt_map: pointer to interrupt mapping description (firmware)
 * @pru_interrupt_map_sz: pru_interrupt_map size
 * @dbg_single_step: debug state variable to set PRU into single step mode
 * @dbg_continuous: debug state variable to restore PRU execution mode
 * @evt_count: number of mapped events
 */
struct pru_rproc {
        int id;
        struct device *dev;
        struct pruss *pruss;
        struct rproc *rproc;
        const struct pru_private_data *data;
        struct pruss_mem_region mem_regions[PRU_IOMEM_MAX];
        const char *fw_name;
        unsigned int *mapped_irq;
        struct pru_irq_rsc *pru_interrupt_map;
        size_t pru_interrupt_map_sz;
        u32 dbg_single_step;
        u32 dbg_continuous;
        u8 evt_count;
};

static inline u32 pru_control_read_reg(struct pru_rproc *pru, unsigned int reg)
{
        return readl_relaxed(pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
}

static inline
void pru_control_write_reg(struct pru_rproc *pru, unsigned int reg, u32 val)
{
        writel_relaxed(val, pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
}

static inline u32 pru_debug_read_reg(struct pru_rproc *pru, unsigned int reg)
{
        return readl_relaxed(pru->mem_regions[PRU_IOMEM_DEBUG].va + reg);
}

static int regs_show(struct seq_file *s, void *data)
{
        struct rproc *rproc = s->private;
        struct pru_rproc *pru = rproc->priv;
        int i, nregs = 32;
        u32 pru_sts;
        int pru_is_running;

        seq_puts(s, "============== Control Registers ==============\n");
        seq_printf(s, "CTRL      := 0x%08x\n",
                   pru_control_read_reg(pru, PRU_CTRL_CTRL));
        pru_sts = pru_control_read_reg(pru, PRU_CTRL_STS);
        seq_printf(s, "STS (PC)  := 0x%08x (0x%08x)\n", pru_sts, pru_sts << 2);
        seq_printf(s, "WAKEUP_EN := 0x%08x\n",
                   pru_control_read_reg(pru, PRU_CTRL_WAKEUP_EN));
        seq_printf(s, "CYCLE     := 0x%08x\n",
                   pru_control_read_reg(pru, PRU_CTRL_CYCLE));
        seq_printf(s, "STALL     := 0x%08x\n",
                   pru_control_read_reg(pru, PRU_CTRL_STALL));
        seq_printf(s, "CTBIR0    := 0x%08x\n",
                   pru_control_read_reg(pru, PRU_CTRL_CTBIR0));
        seq_printf(s, "CTBIR1    := 0x%08x\n",
                   pru_control_read_reg(pru, PRU_CTRL_CTBIR1));
        seq_printf(s, "CTPPR0    := 0x%08x\n",
                   pru_control_read_reg(pru, PRU_CTRL_CTPPR0));
        seq_printf(s, "CTPPR1    := 0x%08x\n",
                   pru_control_read_reg(pru, PRU_CTRL_CTPPR1));

        seq_puts(s, "=============== Debug Registers ===============\n");
        pru_is_running = pru_control_read_reg(pru, PRU_CTRL_CTRL) &
                                CTRL_CTRL_RUNSTATE;
        if (pru_is_running) {
                seq_puts(s, "PRU is executing, cannot print/access debug registers.\n");
                return 0;
        }

        for (i = 0; i < nregs; i++) {
                seq_printf(s, "GPREG%-2d := 0x%08x\tCT_REG%-2d := 0x%08x\n",
                           i, pru_debug_read_reg(pru, PRU_DEBUG_GPREG(i)),
                           i, pru_debug_read_reg(pru, PRU_DEBUG_CT_REG(i)));
        }

        return 0;
}
DEFINE_SHOW_ATTRIBUTE(regs);

/*
 * Control PRU single-step mode
 *
 * This is a debug helper function used for controlling the single-step
 * mode of the PRU. The PRU Debug registers are not accessible when the
 * PRU is in RUNNING state.
 *
 * Writing a non-zero value sets the PRU into single-step mode irrespective
 * of its previous state. The PRU mode is saved only on the first set into
 * a single-step mode. Writing a zero value will restore the PRU into its
 * original mode.
 */
static int pru_rproc_debug_ss_set(void *data, u64 val)
{
        struct rproc *rproc = data;
        struct pru_rproc *pru = rproc->priv;
        u32 reg_val;

        val = val ? 1 : 0;
        if (!val && !pru->dbg_single_step)
                return 0;

        reg_val = pru_control_read_reg(pru, PRU_CTRL_CTRL);

        if (val && !pru->dbg_single_step)
                pru->dbg_continuous = reg_val;

        if (val)
                reg_val |= CTRL_CTRL_SINGLE_STEP | CTRL_CTRL_EN;
        else
                reg_val = pru->dbg_continuous;

        pru->dbg_single_step = val;
        pru_control_write_reg(pru, PRU_CTRL_CTRL, reg_val);

        return 0;
}

static int pru_rproc_debug_ss_get(void *data, u64 *val)
{
        struct rproc *rproc = data;
        struct pru_rproc *pru = rproc->priv;

        *val = pru->dbg_single_step;

        return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(pru_rproc_debug_ss_fops, pru_rproc_debug_ss_get,
                         pru_rproc_debug_ss_set, "%llu\n");

/*
 * Create PRU-specific debugfs entries
 *
 * The entries are created only if the parent remoteproc debugfs directory
 * exists, and will be cleaned up by the remoteproc core.
 */
static void pru_rproc_create_debug_entries(struct rproc *rproc)
{
        if (!rproc->dbg_dir)
                return;

        debugfs_create_file("regs", 0400, rproc->dbg_dir,
                            rproc, &regs_fops);
        debugfs_create_file("single_step", 0600, rproc->dbg_dir,
                            rproc, &pru_rproc_debug_ss_fops);
}

static void pru_dispose_irq_mapping(struct pru_rproc *pru)
{
        if (!pru->mapped_irq)
                return;

        while (pru->evt_count) {
                pru->evt_count--;
                if (pru->mapped_irq[pru->evt_count] > 0)
                        irq_dispose_mapping(pru->mapped_irq[pru->evt_count]);
        }

        kfree(pru->mapped_irq);
        pru->mapped_irq = NULL;
}

/*
 * Parse the custom PRU interrupt map resource and configure the INTC
 * appropriately.
 */
static int pru_handle_intrmap(struct rproc *rproc)
{
        struct device *dev = rproc->dev.parent;
        struct pru_rproc *pru = rproc->priv;
        struct pru_irq_rsc *rsc = pru->pru_interrupt_map;
        struct irq_fwspec fwspec;
        struct device_node *parent, *irq_parent;
        int i, ret = 0;

        /* not having pru_interrupt_map is not an error */
        if (!rsc)
                return 0;

        /* currently supporting only type 0 */
        if (rsc->type != 0) {
                dev_err(dev, "unsupported rsc type: %d\n", rsc->type);
                return -EINVAL;
        }

        if (rsc->num_evts > MAX_PRU_SYS_EVENTS)
                return -EINVAL;

        if (sizeof(*rsc) + rsc->num_evts * sizeof(struct pruss_int_map) !=
            pru->pru_interrupt_map_sz)
                return -EINVAL;

        pru->evt_count = rsc->num_evts;
        pru->mapped_irq = kcalloc(pru->evt_count, sizeof(unsigned int),
                                  GFP_KERNEL);
        if (!pru->mapped_irq) {
                pru->evt_count = 0;
                return -ENOMEM;
        }

        /*
         * parse and fill in system event to interrupt channel and
         * channel-to-host mapping. The interrupt controller to be used
         * for these mappings for a given PRU remoteproc is always its
         * corresponding sibling PRUSS INTC node.
         */
        parent = of_get_parent(dev_of_node(pru->dev));
        if (!parent) {
                kfree(pru->mapped_irq);
                pru->mapped_irq = NULL;
                pru->evt_count = 0;
                return -ENODEV;
        }

        irq_parent = of_get_child_by_name(parent, "interrupt-controller");
        of_node_put(parent);
        if (!irq_parent) {
                kfree(pru->mapped_irq);
                pru->mapped_irq = NULL;
                pru->evt_count = 0;
                return -ENODEV;
        }

        fwspec.fwnode = of_node_to_fwnode(irq_parent);
        fwspec.param_count = 3;
        for (i = 0; i < pru->evt_count; i++) {
                fwspec.param[0] = rsc->pru_intc_map[i].event;
                fwspec.param[1] = rsc->pru_intc_map[i].chnl;
                fwspec.param[2] = rsc->pru_intc_map[i].host;

                dev_dbg(dev, "mapping%d: event %d, chnl %d, host %d\n",
                        i, fwspec.param[0], fwspec.param[1], fwspec.param[2]);

                pru->mapped_irq[i] = irq_create_fwspec_mapping(&fwspec);
                if (!pru->mapped_irq[i]) {
                        dev_err(dev, "failed to get virq for fw mapping %d: event %d chnl %d host %d\n",
                                i, fwspec.param[0], fwspec.param[1],
                                fwspec.param[2]);
                        ret = -EINVAL;
                        goto map_fail;
                }
        }
        of_node_put(irq_parent);

        return ret;

map_fail:
        pru_dispose_irq_mapping(pru);
        of_node_put(irq_parent);

        return ret;
}

static int pru_rproc_start(struct rproc *rproc)
{
        struct device *dev = &rproc->dev;
        struct pru_rproc *pru = rproc->priv;
        const char *names[PRU_TYPE_MAX] = { "PRU", "RTU", "Tx_PRU" };
        u32 val;
        int ret;

        dev_dbg(dev, "starting %s%d: entry-point = 0x%llx\n",
                names[pru->data->type], pru->id, (rproc->bootaddr >> 2));

        ret = pru_handle_intrmap(rproc);
        /*
         * reset references to pru interrupt map - they will stop being valid
         * after rproc_start returns
         */
        pru->pru_interrupt_map = NULL;
        pru->pru_interrupt_map_sz = 0;
        if (ret)
                return ret;

        val = CTRL_CTRL_EN | ((rproc->bootaddr >> 2) << 16);
        pru_control_write_reg(pru, PRU_CTRL_CTRL, val);

        return 0;
}

static int pru_rproc_stop(struct rproc *rproc)
{
        struct device *dev = &rproc->dev;
        struct pru_rproc *pru = rproc->priv;
        const char *names[PRU_TYPE_MAX] = { "PRU", "RTU", "Tx_PRU" };
        u32 val;

        dev_dbg(dev, "stopping %s%d\n", names[pru->data->type], pru->id);

        val = pru_control_read_reg(pru, PRU_CTRL_CTRL);
        val &= ~CTRL_CTRL_EN;
        pru_control_write_reg(pru, PRU_CTRL_CTRL, val);

        /* dispose irq mapping - new firmware can provide new mapping */
        pru_dispose_irq_mapping(pru);

        return 0;
}

/*
 * Convert PRU device address (data spaces only) to kernel virtual address.
 *
 * Each PRU has access to all data memories within the PRUSS, accessible at
 * different ranges. So, look through both its primary and secondary Data
 * RAMs as well as any shared Data RAM to convert a PRU device address to
 * kernel virtual address. Data RAM0 is primary Data RAM for PRU0 and Data
 * RAM1 is primary Data RAM for PRU1.
 */
static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
{
        struct pruss_mem_region dram0, dram1, shrd_ram;
        struct pruss *pruss = pru->pruss;
        u32 offset;
        void *va = NULL;

        if (len == 0)
                return NULL;

        dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
        dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
        /* PRU1 has its local RAM addresses reversed */
        if (pru->id == 1)
                swap(dram0, dram1);
        shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];

        if (da >= PRU_PDRAM_DA && da + len <= PRU_PDRAM_DA + dram0.size) {
                offset = da - PRU_PDRAM_DA;
                va = (__force void *)(dram0.va + offset);
        } else if (da >= PRU_SDRAM_DA &&
                   da + len <= PRU_SDRAM_DA + dram1.size) {
                offset = da - PRU_SDRAM_DA;
                va = (__force void *)(dram1.va + offset);
        } else if (da >= PRU_SHRDRAM_DA &&
                   da + len <= PRU_SHRDRAM_DA + shrd_ram.size) {
                offset = da - PRU_SHRDRAM_DA;
                va = (__force void *)(shrd_ram.va + offset);
        }

        return va;
}

/*
 * Convert PRU device address (instruction space) to kernel virtual address.
 *
 * A PRU does not have an unified address space. Each PRU has its very own
 * private Instruction RAM, and its device address is identical to that of
 * its primary Data RAM device address.
 */
static void *pru_i_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
{
        u32 offset;
        void *va = NULL;

        if (len == 0)
                return NULL;

        /*
         * GNU binutils do not support multiple address spaces. The GNU
         * linker's default linker script places IRAM at an arbitrary high
         * offset, in order to differentiate it from DRAM. Hence we need to
         * strip the artificial offset in the IRAM addresses coming from the
         * ELF file.
         *
         * The TI proprietary linker would never set those higher IRAM address
         * bits anyway. PRU architecture limits the program counter to 16-bit
         * word-address range. This in turn corresponds to 18-bit IRAM
         * byte-address range for ELF.
         *
         * Two more bits are added just in case to make the final 20-bit mask.
         * Idea is to have a safeguard in case TI decides to add banking
         * in future SoCs.
         */
        da &= 0xfffff;

        if (da >= PRU_IRAM_DA &&
            da + len <= PRU_IRAM_DA + pru->mem_regions[PRU_IOMEM_IRAM].size) {
                offset = da - PRU_IRAM_DA;
                va = (__force void *)(pru->mem_regions[PRU_IOMEM_IRAM].va +
                                      offset);
        }

        return va;
}

/*
 * Provide address translations for only PRU Data RAMs through the remoteproc
 * core for any PRU client drivers. The PRU Instruction RAM access is restricted
 * only to the PRU loader code.
 */
static void *pru_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len, bool *is_iomem)
{
        struct pru_rproc *pru = rproc->priv;

        return pru_d_da_to_va(pru, da, len);
}

/* PRU-specific address translator used by PRU loader. */
static void *pru_da_to_va(struct rproc *rproc, u64 da, size_t len, bool is_iram)
{
        struct pru_rproc *pru = rproc->priv;
        void *va;

        if (is_iram)
                va = pru_i_da_to_va(pru, da, len);
        else
                va = pru_d_da_to_va(pru, da, len);

        return va;
}

static struct rproc_ops pru_rproc_ops = {
        .start          = pru_rproc_start,
        .stop           = pru_rproc_stop,
        .da_to_va       = pru_rproc_da_to_va,
};

/*
 * Custom memory copy implementation for ICSSG PRU/RTU/Tx_PRU Cores
 *
 * The ICSSG PRU/RTU/Tx_PRU cores have a memory copying issue with IRAM
 * memories, that is not seen on previous generation SoCs. The data is reflected
 * properly in the IRAM memories only for integer (4-byte) copies. Any unaligned
 * copies result in all the other pre-existing bytes zeroed out within that
 * 4-byte boundary, thereby resulting in wrong text/code in the IRAMs. Also, the
 * IRAM memory port interface does not allow any 8-byte copies (as commonly used
 * by ARM64 memcpy implementation) and throws an exception. The DRAM memory
 * ports do not show this behavior.
 */
static int pru_rproc_memcpy(void *dest, const void *src, size_t count)
{
        const u32 *s = src;
        u32 *d = dest;
        size_t size = count / 4;
        u32 *tmp_src = NULL;

        /*
         * TODO: relax limitation of 4-byte aligned dest addresses and copy
         * sizes
         */
        if ((long)dest % 4 || count % 4)
                return -EINVAL;

        /* src offsets in ELF firmware image can be non-aligned */
        if ((long)src % 4) {
                tmp_src = kmemdup(src, count, GFP_KERNEL);
                if (!tmp_src)
                        return -ENOMEM;
                s = tmp_src;
        }

        while (size--)
                *d++ = *s++;

        kfree(tmp_src);

        return 0;
}

static int
pru_rproc_load_elf_segments(struct rproc *rproc, const struct firmware *fw)
{
        struct pru_rproc *pru = rproc->priv;
        struct device *dev = &rproc->dev;
        struct elf32_hdr *ehdr;
        struct elf32_phdr *phdr;
        int i, ret = 0;
        const u8 *elf_data = fw->data;

        ehdr = (struct elf32_hdr *)elf_data;
        phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);

        /* go through the available ELF segments */
        for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
                u32 da = phdr->p_paddr;
                u32 memsz = phdr->p_memsz;
                u32 filesz = phdr->p_filesz;
                u32 offset = phdr->p_offset;
                bool is_iram;
                void *ptr;

                if (phdr->p_type != PT_LOAD || !filesz)
                        continue;

                dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
                        phdr->p_type, da, memsz, filesz);

                if (filesz > memsz) {
                        dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
                                filesz, memsz);
                        ret = -EINVAL;
                        break;
                }

                if (offset + filesz > fw->size) {
                        dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
                                offset + filesz, fw->size);
                        ret = -EINVAL;
                        break;
                }

                /* grab the kernel address for this device address */
                is_iram = phdr->p_flags & PF_X;
                ptr = pru_da_to_va(rproc, da, memsz, is_iram);
                if (!ptr) {
                        dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
                        ret = -EINVAL;
                        break;
                }

                if (pru->data->is_k3) {
                        ret = pru_rproc_memcpy(ptr, elf_data + phdr->p_offset,
                                               filesz);
                        if (ret) {
                                dev_err(dev, "PRU memory copy failed for da 0x%x memsz 0x%x\n",
                                        da, memsz);
                                break;
                        }
                } else {
                        memcpy(ptr, elf_data + phdr->p_offset, filesz);
                }

                /* skip the memzero logic performed by remoteproc ELF loader */
        }

        return ret;
}

static const void *
pru_rproc_find_interrupt_map(struct device *dev, const struct firmware *fw)
{
        struct elf32_shdr *shdr, *name_table_shdr;
        const char *name_table;
        const u8 *elf_data = fw->data;
        struct elf32_hdr *ehdr = (struct elf32_hdr *)elf_data;
        u16 shnum = ehdr->e_shnum;
        u16 shstrndx = ehdr->e_shstrndx;
        int i;

        /* first, get the section header */
        shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
        /* compute name table section header entry in shdr array */
        name_table_shdr = shdr + shstrndx;
        /* finally, compute the name table section address in elf */
        name_table = elf_data + name_table_shdr->sh_offset;

        for (i = 0; i < shnum; i++, shdr++) {
                u32 size = shdr->sh_size;
                u32 offset = shdr->sh_offset;
                u32 name = shdr->sh_name;

                if (strcmp(name_table + name, ".pru_irq_map"))
                        continue;

                /* make sure we have the entire irq map */
                if (offset + size > fw->size || offset + size < size) {
                        dev_err(dev, ".pru_irq_map section truncated\n");
                        return ERR_PTR(-EINVAL);
                }

                /* make sure irq map has at least the header */
                if (sizeof(struct pru_irq_rsc) > size) {
                        dev_err(dev, "header-less .pru_irq_map section\n");
                        return ERR_PTR(-EINVAL);
                }

                return shdr;
        }

        dev_dbg(dev, "no .pru_irq_map section found for this fw\n");

        return NULL;
}

/*
 * Use a custom parse_fw callback function for dealing with PRU firmware
 * specific sections.
 *
 * The firmware blob can contain optional ELF sections: .resource_table section
 * and .pru_irq_map one. The second one contains the PRUSS interrupt mapping
 * description, which needs to be setup before powering on the PRU core. To
 * avoid RAM wastage this ELF section is not mapped to any ELF segment (by the
 * firmware linker) and therefore is not loaded to PRU memory.
 */
static int pru_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
{
        struct device *dev = &rproc->dev;
        struct pru_rproc *pru = rproc->priv;
        const u8 *elf_data = fw->data;
        const void *shdr;
        u8 class = fw_elf_get_class(fw);
        u64 sh_offset;
        int ret;

        /* load optional rsc table */
        ret = rproc_elf_load_rsc_table(rproc, fw);
        if (ret == -EINVAL)
                dev_dbg(&rproc->dev, "no resource table found for this fw\n");
        else if (ret)
                return ret;

        /* find .pru_interrupt_map section, not having it is not an error */
        shdr = pru_rproc_find_interrupt_map(dev, fw);
        if (IS_ERR(shdr))
                return PTR_ERR(shdr);

        if (!shdr)
                return 0;

        /* preserve pointer to PRU interrupt map together with it size */
        sh_offset = elf_shdr_get_sh_offset(class, shdr);
        pru->pru_interrupt_map = (struct pru_irq_rsc *)(elf_data + sh_offset);
        pru->pru_interrupt_map_sz = elf_shdr_get_sh_size(class, shdr);

        return 0;
}

/*
 * Compute PRU id based on the IRAM addresses. The PRU IRAMs are
 * always at a particular offset within the PRUSS address space.
 */
static int pru_rproc_set_id(struct pru_rproc *pru)
{
        int ret = 0;

        switch (pru->mem_regions[PRU_IOMEM_IRAM].pa & PRU_IRAM_ADDR_MASK) {
        case TX_PRU0_IRAM_ADDR_MASK:
                fallthrough;
        case RTU0_IRAM_ADDR_MASK:
                fallthrough;
        case PRU0_IRAM_ADDR_MASK:
                pru->id = 0;
                break;
        case TX_PRU1_IRAM_ADDR_MASK:
                fallthrough;
        case RTU1_IRAM_ADDR_MASK:
                fallthrough;
        case PRU1_IRAM_ADDR_MASK:
                pru->id = 1;
                break;
        default:
                ret = -EINVAL;
        }

        return ret;
}

static int pru_rproc_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np = dev->of_node;
        struct platform_device *ppdev = to_platform_device(dev->parent);
        struct pru_rproc *pru;
        const char *fw_name;
        struct rproc *rproc = NULL;
        struct resource *res;
        int i, ret;
        const struct pru_private_data *data;
        const char *mem_names[PRU_IOMEM_MAX] = { "iram", "control", "debug" };

        data = of_device_get_match_data(&pdev->dev);
        if (!data)
                return -ENODEV;

        ret = of_property_read_string(np, "firmware-name", &fw_name);
        if (ret) {
                dev_err(dev, "unable to retrieve firmware-name %d\n", ret);
                return ret;
        }

        rproc = devm_rproc_alloc(dev, pdev->name, &pru_rproc_ops, fw_name,
                                 sizeof(*pru));
        if (!rproc) {
                dev_err(dev, "rproc_alloc failed\n");
                return -ENOMEM;
        }
        /* use a custom load function to deal with PRU-specific quirks */
        rproc->ops->load = pru_rproc_load_elf_segments;

        /* use a custom parse function to deal with PRU-specific resources */
        rproc->ops->parse_fw = pru_rproc_parse_fw;

        /* error recovery is not supported for PRUs */
        rproc->recovery_disabled = true;

        /*
         * rproc_add will auto-boot the processor normally, but this is not
         * desired with PRU client driven boot-flow methodology. A PRU
         * application/client driver will boot the corresponding PRU
         * remote-processor as part of its state machine either through the
         * remoteproc sysfs interface or through the equivalent kernel API.
         */
        rproc->auto_boot = false;

        pru = rproc->priv;
        pru->dev = dev;
        pru->data = data;
        pru->pruss = platform_get_drvdata(ppdev);
        pru->rproc = rproc;
        pru->fw_name = fw_name;

        for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
                res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                                   mem_names[i]);
                pru->mem_regions[i].va = devm_ioremap_resource(dev, res);
                if (IS_ERR(pru->mem_regions[i].va)) {
                        dev_err(dev, "failed to parse and map memory resource %d %s\n",
                                i, mem_names[i]);
                        ret = PTR_ERR(pru->mem_regions[i].va);
                        return ret;
                }
                pru->mem_regions[i].pa = res->start;
                pru->mem_regions[i].size = resource_size(res);

                dev_dbg(dev, "memory %8s: pa %pa size 0x%zx va %pK\n",
                        mem_names[i], &pru->mem_regions[i].pa,
                        pru->mem_regions[i].size, pru->mem_regions[i].va);
        }

        ret = pru_rproc_set_id(pru);
        if (ret < 0)
                return ret;

        platform_set_drvdata(pdev, rproc);

        ret = devm_rproc_add(dev, pru->rproc);
        if (ret) {
                dev_err(dev, "rproc_add failed: %d\n", ret);
                return ret;
        }

        pru_rproc_create_debug_entries(rproc);

        dev_dbg(dev, "PRU rproc node %pOF probed successfully\n", np);

        return 0;
}

static int pru_rproc_remove(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct rproc *rproc = platform_get_drvdata(pdev);

        dev_dbg(dev, "%s: removing rproc %s\n", __func__, rproc->name);

        return 0;
}

static const struct pru_private_data pru_data = {
        .type = PRU_TYPE_PRU,
};

static const struct pru_private_data k3_pru_data = {
        .type = PRU_TYPE_PRU,
        .is_k3 = 1,
};

static const struct pru_private_data k3_rtu_data = {
        .type = PRU_TYPE_RTU,
        .is_k3 = 1,
};

static const struct pru_private_data k3_tx_pru_data = {
        .type = PRU_TYPE_TX_PRU,
        .is_k3 = 1,
};

static const struct of_device_id pru_rproc_match[] = {
        { .compatible = "ti,am3356-pru",        .data = &pru_data },
        { .compatible = "ti,am4376-pru",        .data = &pru_data },
        { .compatible = "ti,am5728-pru",        .data = &pru_data },
        { .compatible = "ti,am642-pru",         .data = &k3_pru_data },
        { .compatible = "ti,am642-rtu",         .data = &k3_rtu_data },
        { .compatible = "ti,am642-tx-pru",      .data = &k3_tx_pru_data },
        { .compatible = "ti,k2g-pru",           .data = &pru_data },
        { .compatible = "ti,am654-pru",         .data = &k3_pru_data },
        { .compatible = "ti,am654-rtu",         .data = &k3_rtu_data },
        { .compatible = "ti,am654-tx-pru",      .data = &k3_tx_pru_data },
        { .compatible = "ti,j721e-pru",         .data = &k3_pru_data },
        { .compatible = "ti,j721e-rtu",         .data = &k3_rtu_data },
        { .compatible = "ti,j721e-tx-pru",      .data = &k3_tx_pru_data },
        {},
};
MODULE_DEVICE_TABLE(of, pru_rproc_match);

static struct platform_driver pru_rproc_driver = {
        .driver = {
                .name   = "pru-rproc",
                .of_match_table = pru_rproc_match,
                .suppress_bind_attrs = true,
        },
        .probe  = pru_rproc_probe,
        .remove = pru_rproc_remove,
};
module_platform_driver(pru_rproc_driver);

MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_AUTHOR("Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>");
MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
MODULE_LICENSE("GPL v2");