// SPDX-License-Identifier: GPL-2.0+
/*
 * TI K3 AM65x NAVSS Ring accelerator Manager (RA) subsystem driver
 *
 * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com
 */

#include <common.h>
#include <cpu_func.h>
#include <log.h>
#include <asm/cache.h>
#include <asm/io.h>
#include <malloc.h>
#include <asm/bitops.h>
#include <dm.h>
#include <dm/device_compat.h>
#include <dm/devres.h>
#include <dm/read.h>
#include <dm/uclass.h>
#include <linux/bitops.h>
#include <linux/compat.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/soc/ti/k3-navss-ringacc.h>
#include <linux/soc/ti/ti_sci_protocol.h>
#include <linux/soc/ti/cppi5.h>

#define set_bit(bit, bitmap)    __set_bit(bit, bitmap)
#define clear_bit(bit, bitmap)  __clear_bit(bit, bitmap)
#define dma_free_coherent(dev, size, cpu_addr, dma_handle) \
        dma_free_coherent(cpu_addr)
#define dma_zalloc_coherent(dev, size, dma_handle, flag) \
({ \
        void    *ring_mem_virt; \
        ring_mem_virt = dma_alloc_coherent((size), \
                                           (unsigned long *)(dma_handle)); \
        if (ring_mem_virt) \
                memset(ring_mem_virt, 0, (size)); \
        ring_mem_virt; \
})

static LIST_HEAD(k3_nav_ringacc_list);

static  void ringacc_writel(u32 v, void __iomem *reg)
{
        pr_debug("WRITEL(32): v(%08X)-->reg(%p)\n", v, reg);
        writel(v, reg);
}

static  u32 ringacc_readl(void __iomem *reg)
{
        u32 v;

        v = readl(reg);
        pr_debug("READL(32): v(%08X)<--reg(%p)\n", v, reg);
        return v;
}

#define KNAV_RINGACC_CFG_RING_SIZE_ELCNT_MASK           GENMASK(19, 0)
#define K3_DMARING_RING_CFG_RING_SIZE_ELCNT_MASK                GENMASK(15, 0)

/**
 * struct k3_nav_ring_rt_regs -  The RA Control/Status Registers region
 */
struct k3_nav_ring_rt_regs {
        u32     resv_16[4];
        u32     db;             /* RT Ring N Doorbell Register */
        u32     resv_4[1];
        u32     occ;            /* RT Ring N Occupancy Register */
        u32     indx;           /* RT Ring N Current Index Register */
        u32     hwocc;          /* RT Ring N Hardware Occupancy Register */
        u32     hwindx;         /* RT Ring N Current Index Register */
};

#define KNAV_RINGACC_RT_REGS_STEP       0x1000
#define K3_DMARING_RING_RT_REGS_STEP                    0x2000
#define K3_DMARING_RING_RT_REGS_REVERSE_OFS             0x1000
#define KNAV_RINGACC_RT_OCC_MASK                GENMASK(20, 0)
#define K3_DMARING_RING_RT_OCC_TDOWN_COMPLETE           BIT(31)
#define K3_DMARING_RING_RT_DB_ENTRY_MASK                GENMASK(7, 0)
#define K3_DMARING_RING_RT_DB_TDOWN_ACK         BIT(31)


/**
 * struct k3_nav_ring_fifo_regs -  The Ring Accelerator Queues Registers region
 */
struct k3_nav_ring_fifo_regs {
        u32     head_data[128];         /* Ring Head Entry Data Registers */
        u32     tail_data[128];         /* Ring Tail Entry Data Registers */
        u32     peek_head_data[128];    /* Ring Peek Head Entry Data Regs */
        u32     peek_tail_data[128];    /* Ring Peek Tail Entry Data Regs */
};

#define KNAV_RINGACC_FIFO_WINDOW_SIZE_BYTES  (512U)
#define KNAV_RINGACC_FIFO_REGS_STEP     0x1000
#define KNAV_RINGACC_MAX_DB_RING_CNT    (127U)

/**
 * struct k3_nav_ring_ops -  Ring operations
 */
struct k3_nav_ring_ops {
        int (*push_tail)(struct k3_nav_ring *ring, void *elm);
        int (*push_head)(struct k3_nav_ring *ring, void *elm);
        int (*pop_tail)(struct k3_nav_ring *ring, void *elm);
        int (*pop_head)(struct k3_nav_ring *ring, void *elm);
};

/**
 * struct k3_nav_ring_state - Internal state tracking structure
 *
 * @free: Number of free entries
 * @occ: Occupancy
 * @windex: Write index
 * @rindex: Read index
 */
struct k3_nav_ring_state {
        u32 free;
        u32 occ;
        u32 windex;
        u32 rindex;
        u32 tdown_complete:1;
};

/**
 * struct k3_nav_ring - RA Ring descriptor
 *
 * @cfg - Ring configuration registers
 * @rt - Ring control/status registers
 * @fifos - Ring queues registers
 * @ring_mem_dma - Ring buffer dma address
 * @ring_mem_virt - Ring buffer virt address
 * @ops - Ring operations
 * @size - Ring size in elements
 * @elm_size - Size of the ring element
 * @mode - Ring mode
 * @flags - flags
 * @ring_id - Ring Id
 * @parent - Pointer on struct @k3_nav_ringacc
 * @use_count - Use count for shared rings
 */
struct k3_nav_ring {
        struct k3_nav_ring_cfg_regs __iomem *cfg;
        struct k3_nav_ring_rt_regs __iomem *rt;
        struct k3_nav_ring_fifo_regs __iomem *fifos;
        dma_addr_t      ring_mem_dma;
        void            *ring_mem_virt;
        struct k3_nav_ring_ops *ops;
        u32             size;
        enum k3_nav_ring_size elm_size;
        enum k3_nav_ring_mode mode;
        u32             flags;
#define KNAV_RING_FLAG_BUSY     BIT(1)
#define K3_NAV_RING_FLAG_SHARED BIT(2)
#define K3_NAV_RING_FLAG_REVERSE BIT(3)
        struct k3_nav_ring_state state;
        u32             ring_id;
        struct k3_nav_ringacc   *parent;
        u32             use_count;
};

struct k3_nav_ringacc_ops {
        int (*init)(struct udevice *dev, struct k3_nav_ringacc *ringacc);
};

/**
 * struct k3_nav_ringacc - Rings accelerator descriptor
 *
 * @dev - pointer on RA device
 * @num_rings - number of ring in RA
 * @rm_gp_range - general purpose rings range from tisci
 * @dma_ring_reset_quirk - DMA reset w/a enable
 * @num_proxies - number of RA proxies
 * @rings - array of rings descriptors (struct @k3_nav_ring)
 * @list - list of RAs in the system
 * @tisci - pointer ti-sci handle
 * @tisci_ring_ops - ti-sci rings ops
 * @tisci_dev_id - ti-sci device id
 * @ops: SoC specific ringacc operation
 * @dual_ring: indicate k3_dmaring dual ring support
 */
struct k3_nav_ringacc {
        struct udevice *dev;
        u32 num_rings; /* number of rings in Ringacc module */
        unsigned long *rings_inuse;
        struct ti_sci_resource *rm_gp_range;
        bool dma_ring_reset_quirk;
        u32 num_proxies;

        struct k3_nav_ring *rings;
        struct list_head list;

        const struct ti_sci_handle *tisci;
        const struct ti_sci_rm_ringacc_ops *tisci_ring_ops;
        u32  tisci_dev_id;

        const struct k3_nav_ringacc_ops *ops;
        bool dual_ring;
};

#include "k3-navss-ringacc-u-boot.c"

static int k3_nav_ringacc_ring_read_occ(struct k3_nav_ring *ring)
{
        return readl(&ring->rt->occ) & KNAV_RINGACC_RT_OCC_MASK;
}

static void k3_nav_ringacc_ring_update_occ(struct k3_nav_ring *ring)
{
        u32 val;

        val = readl(&ring->rt->occ);

        ring->state.occ = val & KNAV_RINGACC_RT_OCC_MASK;
        ring->state.tdown_complete = !!(val & K3_DMARING_RING_RT_OCC_TDOWN_COMPLETE);
}

static void *k3_nav_ringacc_get_elm_addr(struct k3_nav_ring *ring, u32 idx)
{
        return (idx * (4 << ring->elm_size) + ring->ring_mem_virt);
}

static int k3_nav_ringacc_ring_push_mem(struct k3_nav_ring *ring, void *elem);
static int k3_nav_ringacc_ring_pop_mem(struct k3_nav_ring *ring, void *elem);
static int k3_dmaring_ring_fwd_pop_mem(struct k3_nav_ring *ring, void *elem);
static int k3_dmaring_ring_reverse_pop_mem(struct k3_nav_ring *ring, void *elem);

static struct k3_nav_ring_ops k3_nav_mode_ring_ops = {
                .push_tail = k3_nav_ringacc_ring_push_mem,
                .pop_head = k3_nav_ringacc_ring_pop_mem,
};

static struct k3_nav_ring_ops k3_dmaring_fwd_ring_ops = {
                .push_tail = k3_nav_ringacc_ring_push_mem,
                .pop_head = k3_dmaring_ring_fwd_pop_mem,
};

static struct k3_nav_ring_ops k3_dmaring_reverse_ring_ops = {
                .pop_head = k3_dmaring_ring_reverse_pop_mem,
};

struct udevice *k3_nav_ringacc_get_dev(struct k3_nav_ringacc *ringacc)
{
        return ringacc->dev;
}

struct k3_nav_ring *k3_nav_ringacc_request_ring(struct k3_nav_ringacc *ringacc,
                                                int id)
{
        if (id == K3_NAV_RINGACC_RING_ID_ANY) {
                /* Request for any general purpose ring */
                struct ti_sci_resource_desc *gp_rings =
                                        &ringacc->rm_gp_range->desc[0];
                unsigned long size;

                size = gp_rings->start + gp_rings->num;
                id = find_next_zero_bit(ringacc->rings_inuse,
                                        size, gp_rings->start);
                if (id == size)
                        goto error;
        } else if (id < 0) {
                goto error;
        }

        if (test_bit(id, ringacc->rings_inuse) &&
            !(ringacc->rings[id].flags & K3_NAV_RING_FLAG_SHARED))
                goto error;
        else if (ringacc->rings[id].flags & K3_NAV_RING_FLAG_SHARED)
                goto out;

        if (!try_module_get(ringacc->dev->driver->owner))
                goto error;

        pr_debug("Giving ring#%d\n", id);

        set_bit(id, ringacc->rings_inuse);
out:
        ringacc->rings[id].use_count++;
        return &ringacc->rings[id];

error:
        return NULL;
}

static int k3_dmaring_ring_request_rings_pair(struct k3_nav_ringacc *ringacc,
                                              int fwd_id, int compl_id,
                                              struct k3_nav_ring **fwd_ring,
                                              struct k3_nav_ring **compl_ring)
{
        /* k3_dmaring: fwd_id == compl_id, so we ignore compl_id */
        if (fwd_id < 0)
                return -EINVAL;

        if (test_bit(fwd_id, ringacc->rings_inuse))
                return -EBUSY;

        *fwd_ring = &ringacc->rings[fwd_id];
        *compl_ring = &ringacc->rings[fwd_id + ringacc->num_rings];
        set_bit(fwd_id, ringacc->rings_inuse);
        ringacc->rings[fwd_id].use_count++;
        dev_dbg(ringacc->dev, "Giving ring#%d\n", fwd_id);

        return 0;
}

int k3_nav_ringacc_request_rings_pair(struct k3_nav_ringacc *ringacc,
                                      int fwd_id, int compl_id,
                                      struct k3_nav_ring **fwd_ring,
                                      struct k3_nav_ring **compl_ring)
{
        int ret = 0;

        if (!fwd_ring || !compl_ring)
                return -EINVAL;

        if (ringacc->dual_ring)
                return k3_dmaring_ring_request_rings_pair(ringacc, fwd_id, compl_id,
                                                    fwd_ring, compl_ring);

        *fwd_ring = k3_nav_ringacc_request_ring(ringacc, fwd_id);
        if (!(*fwd_ring))
                return -ENODEV;

        *compl_ring = k3_nav_ringacc_request_ring(ringacc, compl_id);
        if (!(*compl_ring)) {
                k3_nav_ringacc_ring_free(*fwd_ring);
                ret = -ENODEV;
        }

        return ret;
}

static void k3_ringacc_ring_reset_sci(struct k3_nav_ring *ring)
{
        struct k3_nav_ringacc *ringacc = ring->parent;
        int ret;

        if (IS_ENABLED(CONFIG_K3_DM_FW))
                return k3_ringacc_ring_reset_raw(ring);

        ret = ringacc->tisci_ring_ops->config(
                        ringacc->tisci,
                        TI_SCI_MSG_VALUE_RM_RING_COUNT_VALID,
                        ringacc->tisci_dev_id,
                        ring->ring_id,
                        0,
                        0,
                        ring->size,
                        0,
                        0,
                        0);
        if (ret)
                dev_err(ringacc->dev, "TISCI reset ring fail (%d) ring_idx %d\n",
                        ret, ring->ring_id);
}

void k3_nav_ringacc_ring_reset(struct k3_nav_ring *ring)
{
        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return;

        memset(&ring->state, 0, sizeof(ring->state));

        k3_ringacc_ring_reset_sci(ring);
}

static void k3_ringacc_ring_reconfig_qmode_sci(struct k3_nav_ring *ring,
                                               enum k3_nav_ring_mode mode)
{
        struct k3_nav_ringacc *ringacc = ring->parent;
        int ret;

        if (IS_ENABLED(CONFIG_K3_DM_FW))
                return k3_ringacc_ring_reconfig_qmode_raw(ring, mode);

        ret = ringacc->tisci_ring_ops->config(
                        ringacc->tisci,
                        TI_SCI_MSG_VALUE_RM_RING_MODE_VALID,
                        ringacc->tisci_dev_id,
                        ring->ring_id,
                        0,
                        0,
                        0,
                        mode,
                        0,
                        0);
        if (ret)
                dev_err(ringacc->dev, "TISCI reconf qmode fail (%d) ring_idx %d\n",
                        ret, ring->ring_id);
}

void k3_nav_ringacc_ring_reset_dma(struct k3_nav_ring *ring, u32 occ)
{
        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return;

        if (!ring->parent->dma_ring_reset_quirk) {
                k3_nav_ringacc_ring_reset(ring);
                return;
        }

        if (!occ)
                occ = ringacc_readl(&ring->rt->occ);

        if (occ) {
                u32 db_ring_cnt, db_ring_cnt_cur;

                pr_debug("%s %u occ: %u\n", __func__,
                         ring->ring_id, occ);
                /* 2. Reset the ring */
                k3_ringacc_ring_reset_sci(ring);

                /*
                 * 3. Setup the ring in ring/doorbell mode
                 * (if not already in this mode)
                 */
                if (ring->mode != K3_NAV_RINGACC_RING_MODE_RING)
                        k3_ringacc_ring_reconfig_qmode_sci(
                                        ring, K3_NAV_RINGACC_RING_MODE_RING);
                /*
                 * 4. Ring the doorbell 2**22 – ringOcc times.
                 * This will wrap the internal UDMAP ring state occupancy
                 * counter (which is 21-bits wide) to 0.
                 */
                db_ring_cnt = (1U << 22) - occ;

                while (db_ring_cnt != 0) {
                        /*
                         * Ring the doorbell with the maximum count each
                         * iteration if possible to minimize the total
                         * of writes
                         */
                        if (db_ring_cnt > KNAV_RINGACC_MAX_DB_RING_CNT)
                                db_ring_cnt_cur = KNAV_RINGACC_MAX_DB_RING_CNT;
                        else
                                db_ring_cnt_cur = db_ring_cnt;

                        writel(db_ring_cnt_cur, &ring->rt->db);
                        db_ring_cnt -= db_ring_cnt_cur;
                }

                /* 5. Restore the original ring mode (if not ring mode) */
                if (ring->mode != K3_NAV_RINGACC_RING_MODE_RING)
                        k3_ringacc_ring_reconfig_qmode_sci(ring, ring->mode);
        }

        /* 2. Reset the ring */
        k3_nav_ringacc_ring_reset(ring);
}

static void k3_ringacc_ring_free_sci(struct k3_nav_ring *ring)
{
        struct k3_nav_ringacc *ringacc = ring->parent;
        int ret;

        if (IS_ENABLED(CONFIG_K3_DM_FW))
                return k3_ringacc_ring_free_raw(ring);

        ret = ringacc->tisci_ring_ops->config(
                        ringacc->tisci,
                        TI_SCI_MSG_VALUE_RM_ALL_NO_ORDER,
                        ringacc->tisci_dev_id,
                        ring->ring_id,
                        0,
                        0,
                        0,
                        0,
                        0,
                        0);
        if (ret)
                dev_err(ringacc->dev, "TISCI ring free fail (%d) ring_idx %d\n",
                        ret, ring->ring_id);
}

int k3_nav_ringacc_ring_free(struct k3_nav_ring *ring)
{
        struct k3_nav_ringacc *ringacc;

        if (!ring)
                return -EINVAL;

        ringacc = ring->parent;

        /*
         * k3_dmaring: rings shared memory and configuration, only forward ring is
         * configured and reverse ring considered as slave.
         */
        if (ringacc->dual_ring && (ring->flags & K3_NAV_RING_FLAG_REVERSE))
                return 0;

        pr_debug("%s flags: 0x%08x\n", __func__, ring->flags);

        if (!test_bit(ring->ring_id, ringacc->rings_inuse))
                return -EINVAL;

        if (--ring->use_count)
                goto out;

        if (!(ring->flags & KNAV_RING_FLAG_BUSY))
                goto no_init;

        k3_ringacc_ring_free_sci(ring);

        dma_free_coherent(ringacc->dev,
                          ring->size * (4 << ring->elm_size),
                          ring->ring_mem_virt, ring->ring_mem_dma);
        ring->flags &= ~KNAV_RING_FLAG_BUSY;
        ring->ops = NULL;

no_init:
        clear_bit(ring->ring_id, ringacc->rings_inuse);

        module_put(ringacc->dev->driver->owner);

out:
        return 0;
}

u32 k3_nav_ringacc_get_ring_id(struct k3_nav_ring *ring)
{
        if (!ring)
                return -EINVAL;

        return ring->ring_id;
}

static int k3_nav_ringacc_ring_cfg_sci(struct k3_nav_ring *ring)
{
        struct k3_nav_ringacc *ringacc = ring->parent;
        u32 ring_idx;
        int ret;

        if (!ringacc->tisci)
                return -EINVAL;

        ring_idx = ring->ring_id;
        ret = ringacc->tisci_ring_ops->config(
                        ringacc->tisci,
                        TI_SCI_MSG_VALUE_RM_ALL_NO_ORDER,
                        ringacc->tisci_dev_id,
                        ring_idx,
                        lower_32_bits(ring->ring_mem_dma),
                        upper_32_bits(ring->ring_mem_dma),
                        ring->size,
                        ring->mode,
                        ring->elm_size,
                        0);
        if (ret) {
                dev_err(ringacc->dev, "TISCI config ring fail (%d) ring_idx %d\n",
                        ret, ring_idx);
                return ret;
        }

        /*
         * Above TI SCI call handles firewall configuration, cfg
         * register configuration still has to be done locally in
         * absence of RM services.
         */
        if (IS_ENABLED(CONFIG_K3_DM_FW))
                k3_nav_ringacc_ring_cfg_raw(ring);

        return 0;
}

static int k3_dmaring_ring_cfg(struct k3_nav_ring *ring, struct k3_nav_ring_cfg *cfg)
{
        struct k3_nav_ringacc *ringacc;
        struct k3_nav_ring *reverse_ring;
        int ret = 0;

        if (cfg->elm_size != K3_NAV_RINGACC_RING_ELSIZE_8 ||
            cfg->mode != K3_NAV_RINGACC_RING_MODE_RING ||
            cfg->size & ~K3_DMARING_RING_CFG_RING_SIZE_ELCNT_MASK)
                return -EINVAL;

        ringacc = ring->parent;

        /*
         * k3_dmaring: rings shared memory and configuration, only forward ring is
         * configured and reverse ring considered as slave.
         */
        if (ringacc->dual_ring && (ring->flags & K3_NAV_RING_FLAG_REVERSE))
                return 0;

        if (!test_bit(ring->ring_id, ringacc->rings_inuse))
                return -EINVAL;

        ring->size = cfg->size;
        ring->elm_size = cfg->elm_size;
        ring->mode = cfg->mode;
        memset(&ring->state, 0, sizeof(ring->state));

        ring->ops = &k3_dmaring_fwd_ring_ops;

        ring->ring_mem_virt =
                dma_alloc_coherent(ring->size * (4 << ring->elm_size),
                                   (unsigned long *)&ring->ring_mem_dma);
        if (!ring->ring_mem_virt) {
                dev_err(ringacc->dev, "Failed to alloc ring mem\n");
                ret = -ENOMEM;
                goto err_free_ops;
        }

        ret = k3_nav_ringacc_ring_cfg_sci(ring);
        if (ret)
                goto err_free_mem;

        ring->flags |= KNAV_RING_FLAG_BUSY;

        /* k3_dmaring: configure reverse ring */
        reverse_ring = &ringacc->rings[ring->ring_id + ringacc->num_rings];
        reverse_ring->size = cfg->size;
        reverse_ring->elm_size = cfg->elm_size;
        reverse_ring->mode = cfg->mode;
        memset(&reverse_ring->state, 0, sizeof(reverse_ring->state));
        reverse_ring->ops = &k3_dmaring_reverse_ring_ops;

        reverse_ring->ring_mem_virt = ring->ring_mem_virt;
        reverse_ring->ring_mem_dma = ring->ring_mem_dma;
        reverse_ring->flags |= KNAV_RING_FLAG_BUSY;

        return 0;

err_free_mem:
        dma_free_coherent(ringacc->dev,
                          ring->size * (4 << ring->elm_size),
                          ring->ring_mem_virt,
                          ring->ring_mem_dma);
err_free_ops:
        ring->ops = NULL;
        return ret;
}

int k3_nav_ringacc_ring_cfg(struct k3_nav_ring *ring,
                            struct k3_nav_ring_cfg *cfg)
{
        struct k3_nav_ringacc *ringacc = ring->parent;
        int ret = 0;

        if (!ring || !cfg)
                return -EINVAL;

        if (ringacc->dual_ring)
                return k3_dmaring_ring_cfg(ring, cfg);

        if (cfg->elm_size > K3_NAV_RINGACC_RING_ELSIZE_256 ||
            cfg->mode > K3_NAV_RINGACC_RING_MODE_QM ||
            cfg->size & ~KNAV_RINGACC_CFG_RING_SIZE_ELCNT_MASK ||
            !test_bit(ring->ring_id, ringacc->rings_inuse))
                return -EINVAL;

        if (ring->use_count != 1)
                return 0;

        ring->size = cfg->size;
        ring->elm_size = cfg->elm_size;
        ring->mode = cfg->mode;
        memset(&ring->state, 0, sizeof(ring->state));

        switch (ring->mode) {
        case K3_NAV_RINGACC_RING_MODE_RING:
                ring->ops = &k3_nav_mode_ring_ops;
                break;
        default:
                ring->ops = NULL;
                ret = -EINVAL;
                goto err_free_ops;
        };

        ring->ring_mem_virt =
                        dma_zalloc_coherent(ringacc->dev,
                                            ring->size * (4 << ring->elm_size),
                                            &ring->ring_mem_dma, GFP_KERNEL);
        if (!ring->ring_mem_virt) {
                dev_err(ringacc->dev, "Failed to alloc ring mem\n");
                ret = -ENOMEM;
                goto err_free_ops;
        }

        ret = k3_nav_ringacc_ring_cfg_sci(ring);

        if (ret)
                goto err_free_mem;

        ring->flags |= KNAV_RING_FLAG_BUSY;
        ring->flags |= (cfg->flags & K3_NAV_RINGACC_RING_SHARED) ?
                        K3_NAV_RING_FLAG_SHARED : 0;

        return 0;

err_free_mem:
        dma_free_coherent(ringacc->dev,
                          ring->size * (4 << ring->elm_size),
                          ring->ring_mem_virt,
                          ring->ring_mem_dma);
err_free_ops:
        ring->ops = NULL;
        return ret;
}

u32 k3_nav_ringacc_ring_get_size(struct k3_nav_ring *ring)
{
        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return -EINVAL;

        return ring->size;
}

u32 k3_nav_ringacc_ring_get_free(struct k3_nav_ring *ring)
{
        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return -EINVAL;

        if (!ring->state.free)
                ring->state.free = ring->size - ringacc_readl(&ring->rt->occ);

        return ring->state.free;
}

u32 k3_nav_ringacc_ring_get_occ(struct k3_nav_ring *ring)
{
        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return -EINVAL;

        return ringacc_readl(&ring->rt->occ);
}

u32 k3_nav_ringacc_ring_is_full(struct k3_nav_ring *ring)
{
        return !k3_nav_ringacc_ring_get_free(ring);
}

enum k3_ringacc_access_mode {
        K3_RINGACC_ACCESS_MODE_PUSH_HEAD,
        K3_RINGACC_ACCESS_MODE_POP_HEAD,
        K3_RINGACC_ACCESS_MODE_PUSH_TAIL,
        K3_RINGACC_ACCESS_MODE_POP_TAIL,
        K3_RINGACC_ACCESS_MODE_PEEK_HEAD,
        K3_RINGACC_ACCESS_MODE_PEEK_TAIL,
};

static int k3_dmaring_ring_fwd_pop_mem(struct k3_nav_ring *ring, void *elem)
{
        void *elem_ptr;
        u32 elem_idx;

        /*
         * k3_dmaring: forward ring is always tied DMA channel and HW does not
         * maintain any state data required for POP operation and its unknown
         * how much elements were consumed by HW. So, to actually
         * do POP, the read pointer has to be recalculated every time.
         */
        ring->state.occ = k3_nav_ringacc_ring_read_occ(ring);
        if (ring->state.windex >= ring->state.occ)
                elem_idx = ring->state.windex - ring->state.occ;
        else
                elem_idx = ring->size - (ring->state.occ - ring->state.windex);

        elem_ptr = k3_nav_ringacc_get_elm_addr(ring, elem_idx);
        invalidate_dcache_range((unsigned long)ring->ring_mem_virt,
                                ALIGN((unsigned long)ring->ring_mem_virt +
                                      ring->size * (4 << ring->elm_size),
                                      ARCH_DMA_MINALIGN));

        memcpy(elem, elem_ptr, (4 << ring->elm_size));

        ring->state.occ--;
        writel(-1, &ring->rt->db);

        dev_dbg(ring->parent->dev, "%s: occ%d Windex%d Rindex%d pos_ptr%px\n",
                __func__, ring->state.occ, ring->state.windex, elem_idx,
                elem_ptr);
        return 0;
}

static int k3_dmaring_ring_reverse_pop_mem(struct k3_nav_ring *ring, void *elem)
{
        void *elem_ptr;

        elem_ptr = k3_nav_ringacc_get_elm_addr(ring, ring->state.rindex);

        if (ring->state.occ) {
                invalidate_dcache_range((unsigned long)ring->ring_mem_virt,
                                        ALIGN((unsigned long)ring->ring_mem_virt +
                                        ring->size * (4 << ring->elm_size),
                                        ARCH_DMA_MINALIGN));

                memcpy(elem, elem_ptr, (4 << ring->elm_size));
                ring->state.rindex = (ring->state.rindex + 1) % ring->size;
                ring->state.occ--;
                writel(-1 & K3_DMARING_RING_RT_DB_ENTRY_MASK, &ring->rt->db);
        }

        dev_dbg(ring->parent->dev, "%s: occ%d index%d pos_ptr%px\n",
                __func__, ring->state.occ, ring->state.rindex, elem_ptr);
        return 0;
}

static int k3_nav_ringacc_ring_push_mem(struct k3_nav_ring *ring, void *elem)
{
        void *elem_ptr;

        elem_ptr = k3_nav_ringacc_get_elm_addr(ring, ring->state.windex);

        memcpy(elem_ptr, elem, (4 << ring->elm_size));

        flush_dcache_range((unsigned long)ring->ring_mem_virt,
                           ALIGN((unsigned long)ring->ring_mem_virt +
                                 ring->size * (4 << ring->elm_size),
                                 ARCH_DMA_MINALIGN));

        ring->state.windex = (ring->state.windex + 1) % ring->size;
        ring->state.free--;
        ringacc_writel(1, &ring->rt->db);

        pr_debug("ring_push_mem: free%d index%d\n",
                 ring->state.free, ring->state.windex);

        return 0;
}

static int k3_nav_ringacc_ring_pop_mem(struct k3_nav_ring *ring, void *elem)
{
        void *elem_ptr;

        elem_ptr = k3_nav_ringacc_get_elm_addr(ring, ring->state.rindex);

        invalidate_dcache_range((unsigned long)ring->ring_mem_virt,
                                ALIGN((unsigned long)ring->ring_mem_virt +
                                      ring->size * (4 << ring->elm_size),
                                      ARCH_DMA_MINALIGN));

        memcpy(elem, elem_ptr, (4 << ring->elm_size));

        ring->state.rindex = (ring->state.rindex + 1) % ring->size;
        ring->state.occ--;
        ringacc_writel(-1, &ring->rt->db);

        pr_debug("ring_pop_mem: occ%d index%d pos_ptr%p\n",
                 ring->state.occ, ring->state.rindex, elem_ptr);
        return 0;
}

int k3_nav_ringacc_ring_push(struct k3_nav_ring *ring, void *elem)
{
        int ret = -EOPNOTSUPP;

        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return -EINVAL;

        pr_debug("ring_push%d: free%d index%d\n",
                 ring->ring_id, ring->state.free, ring->state.windex);

        if (k3_nav_ringacc_ring_is_full(ring))
                return -ENOMEM;

        if (ring->ops && ring->ops->push_tail)
                ret = ring->ops->push_tail(ring, elem);

        return ret;
}

int k3_nav_ringacc_ring_push_head(struct k3_nav_ring *ring, void *elem)
{
        int ret = -EOPNOTSUPP;

        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return -EINVAL;

        pr_debug("ring_push_head: free%d index%d\n",
                 ring->state.free, ring->state.windex);

        if (k3_nav_ringacc_ring_is_full(ring))
                return -ENOMEM;

        if (ring->ops && ring->ops->push_head)
                ret = ring->ops->push_head(ring, elem);

        return ret;
}

int k3_nav_ringacc_ring_pop(struct k3_nav_ring *ring, void *elem)
{
        int ret = -EOPNOTSUPP;

        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return -EINVAL;

        if (!ring->state.occ)
                k3_nav_ringacc_ring_update_occ(ring);

        pr_debug("ring_pop%d: occ%d index%d\n",
                 ring->ring_id, ring->state.occ, ring->state.rindex);

        if (!ring->state.occ && !ring->state.tdown_complete)
                return -ENODATA;

        if (ring->ops && ring->ops->pop_head)
                ret = ring->ops->pop_head(ring, elem);

        return ret;
}

int k3_nav_ringacc_ring_pop_tail(struct k3_nav_ring *ring, void *elem)
{
        int ret = -EOPNOTSUPP;

        if (!ring || !(ring->flags & KNAV_RING_FLAG_BUSY))
                return -EINVAL;

        if (!ring->state.occ)
                k3_nav_ringacc_ring_update_occ(ring);

        pr_debug("ring_pop_tail: occ%d index%d\n",
                 ring->state.occ, ring->state.rindex);

        if (!ring->state.occ)
                return -ENODATA;

        if (ring->ops && ring->ops->pop_tail)
                ret = ring->ops->pop_tail(ring, elem);

        return ret;
}

static int k3_nav_ringacc_probe_dt(struct k3_nav_ringacc *ringacc)
{
        struct udevice *dev = ringacc->dev;
        struct udevice *devp = dev;
        struct udevice *tisci_dev = NULL;
        int ret;

        ringacc->num_rings = dev_read_u32_default(dev, "ti,num-rings", 0);
        if (!ringacc->num_rings) {
                dev_err(dev, "ti,num-rings read failure %d\n", ret);
                return -EINVAL;
        }

        ringacc->dma_ring_reset_quirk =
                        dev_read_bool(dev, "ti,dma-ring-reset-quirk");

        ret = uclass_get_device_by_phandle(UCLASS_FIRMWARE, devp,
                                           "ti,sci", &tisci_dev);
        if (ret) {
                pr_debug("TISCI RA RM get failed (%d)\n", ret);
                ringacc->tisci = NULL;
                return -ENODEV;
        }
        ringacc->tisci = (struct ti_sci_handle *)
                         (ti_sci_get_handle_from_sysfw(tisci_dev));

        ret = dev_read_u32_default(devp, "ti,sci", 0);
        if (!ret) {
                dev_err(dev, "TISCI RA RM disabled\n");
                ringacc->tisci = NULL;
                return ret;
        }

        ret = dev_read_u32(devp, "ti,sci-dev-id", &ringacc->tisci_dev_id);
        if (ret) {
                dev_err(dev, "ti,sci-dev-id read failure %d\n", ret);
                ringacc->tisci = NULL;
                return ret;
        }

        ringacc->rm_gp_range = devm_ti_sci_get_of_resource(
                                        ringacc->tisci, dev,
                                        ringacc->tisci_dev_id,
                                        "ti,sci-rm-range-gp-rings");
        if (IS_ERR(ringacc->rm_gp_range))
                ret = PTR_ERR(ringacc->rm_gp_range);

        return 0;
}

static int k3_nav_ringacc_init(struct udevice *dev, struct k3_nav_ringacc *ringacc)
{
        void __iomem *base_cfg, *base_rt;
        int ret, i;

        ret = k3_nav_ringacc_probe_dt(ringacc);
        if (ret)
                return ret;

        base_cfg = dev_remap_addr_name(dev, "cfg");
        pr_debug("cfg %p\n", base_cfg);
        if (!base_cfg)
                return -EINVAL;

        base_rt = (uint32_t *)devfdt_get_addr_name(dev, "rt");
        pr_debug("rt %p\n", base_rt);
        if (IS_ERR(base_rt))
                return PTR_ERR(base_rt);

        ringacc->rings = devm_kzalloc(dev,
                                      sizeof(*ringacc->rings) *
                                      ringacc->num_rings,
                                      GFP_KERNEL);
        ringacc->rings_inuse = devm_kcalloc(dev,
                                            BITS_TO_LONGS(ringacc->num_rings),
                                            sizeof(unsigned long), GFP_KERNEL);

        if (!ringacc->rings || !ringacc->rings_inuse)
                return -ENOMEM;

        for (i = 0; i < ringacc->num_rings; i++) {
                ringacc->rings[i].cfg = base_cfg +
                                        KNAV_RINGACC_CFG_REGS_STEP * i;
                ringacc->rings[i].rt = base_rt +
                                       KNAV_RINGACC_RT_REGS_STEP * i;
                ringacc->rings[i].parent = ringacc;
                ringacc->rings[i].ring_id = i;
        }
        dev_set_drvdata(dev, ringacc);

        ringacc->tisci_ring_ops = &ringacc->tisci->ops.rm_ring_ops;

        list_add_tail(&ringacc->list, &k3_nav_ringacc_list);

        dev_info(dev, "Ring Accelerator probed rings:%u, gp-rings[%u,%u] sci-dev-id:%u\n",
                 ringacc->num_rings,
                 ringacc->rm_gp_range->desc[0].start,
                 ringacc->rm_gp_range->desc[0].num,
                 ringacc->tisci_dev_id);
        dev_info(dev, "dma-ring-reset-quirk: %s\n",
                 ringacc->dma_ring_reset_quirk ? "enabled" : "disabled");
        return 0;
}

struct k3_nav_ringacc *k3_ringacc_dmarings_init(struct udevice *dev,
                                                struct k3_ringacc_init_data *data)
{
        struct k3_nav_ringacc *ringacc;
        void __iomem *base_rt;
        int i;

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

        ringacc->dual_ring = true;

        ringacc->dev = dev;
        ringacc->num_rings = data->num_rings;
        ringacc->tisci = data->tisci;
        ringacc->tisci_dev_id = data->tisci_dev_id;

        base_rt = (uint32_t *)devfdt_get_addr_name(dev, "ringrt");
        if (IS_ERR(base_rt))
                return base_rt;

        ringacc->rings = devm_kzalloc(dev,
                                      sizeof(*ringacc->rings) *
                                      ringacc->num_rings * 2,
                                      GFP_KERNEL);
        ringacc->rings_inuse = devm_kcalloc(dev,
                                            BITS_TO_LONGS(ringacc->num_rings),
                                            sizeof(unsigned long), GFP_KERNEL);

        if (!ringacc->rings || !ringacc->rings_inuse)
                return ERR_PTR(-ENOMEM);

        for (i = 0; i < ringacc->num_rings; i++) {
                struct k3_nav_ring *ring = &ringacc->rings[i];

                ring->rt = base_rt + K3_DMARING_RING_RT_REGS_STEP * i;
                ring->parent = ringacc;
                ring->ring_id = i;

                ring = &ringacc->rings[ringacc->num_rings + i];
                ring->rt = base_rt + K3_DMARING_RING_RT_REGS_STEP * i +
                           K3_DMARING_RING_RT_REGS_REVERSE_OFS;
                ring->parent = ringacc;
                ring->ring_id = i;
                ring->flags = K3_NAV_RING_FLAG_REVERSE;
        }

        ringacc->tisci_ring_ops = &ringacc->tisci->ops.rm_ring_ops;

        dev_info(dev, "k3_dmaring Ring probed rings:%u, sci-dev-id:%u\n",
                 ringacc->num_rings,
                 ringacc->tisci_dev_id);
        dev_info(dev, "dma-ring-reset-quirk: %s\n",
                 ringacc->dma_ring_reset_quirk ? "enabled" : "disabled");

        return ringacc;
}

struct ringacc_match_data {
        struct k3_nav_ringacc_ops ops;
};

static struct ringacc_match_data k3_nav_ringacc_data = {
        .ops = {
                .init = k3_nav_ringacc_init,
        },
};

static const struct udevice_id knav_ringacc_ids[] = {
        { .compatible = "ti,am654-navss-ringacc", .data = (ulong)&k3_nav_ringacc_data, },
        {},
};

static int k3_nav_ringacc_probe(struct udevice *dev)
{
        struct k3_nav_ringacc *ringacc;
        int ret;
        const struct ringacc_match_data *match_data;

        match_data = (struct ringacc_match_data *)dev_get_driver_data(dev);

        ringacc = dev_get_priv(dev);
        if (!ringacc)
                return -ENOMEM;

        ringacc->dev = dev;
        ringacc->ops = &match_data->ops;
        ret = ringacc->ops->init(dev, ringacc);
        if (ret)
                return ret;

        return 0;
}

U_BOOT_DRIVER(k3_navss_ringacc) = {
        .name   = "k3-navss-ringacc",
        .id     = UCLASS_MISC,
        .of_match = knav_ringacc_ids,
        .probe = k3_nav_ringacc_probe,
        .priv_auto      = sizeof(struct k3_nav_ringacc),
};