/*      $NetBSD: octeon_smi.c,v 1.9 2022/09/29 07:00:46 skrll Exp $     */

/*
 * Copyright (c) 2007 Internet Initiative Japan, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: octeon_smi.c,v 1.9 2022/09/29 07:00:46 skrll Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/mbuf.h>
#include <sys/queue.h>
#include <sys/kmem.h>

#include <mips/locore.h>
#include <mips/cavium/octeonvar.h>
#include <mips/cavium/dev/octeon_fpareg.h>
#include <mips/cavium/dev/octeon_fpavar.h>
#include <mips/cavium/dev/octeon_pipreg.h>
#include <mips/cavium/dev/octeon_smireg.h>
#include <mips/cavium/dev/octeon_smivar.h>
#include <mips/cavium/include/iobusvar.h>

#include <dev/fdt/fdtvar.h>

/*
 * System Management Interface
 *
 *
 * CN30XX  - 1 SMI interface
 * CN31XX  - 1 SMI interface
 * CN38XX  - 1 SMI interface
 * CN50XX  - 1 SMI interface
 * CN52XX  - 2 SMI interfaces
 * CN56XX  - 2 SMI interfaces
 * CN58XX  - 1 SMI interface
 * CN61XX  - 2 SMI interfaces
 * CN63XX  - 2 SMI interfaces
 * CN66XX  - 2 SMI interfaces
 * CN68XX  - 4 SMI interfaces
 * CN70XX  - 2 SMI interfaces
 * CN73XX  - 2 SMI interfaces
 * CN78XX  - 4 SMI interfaces
 * CNF71XX - 2 SMI interfaces
 * CNF75XX - 2 SMI interfaces
 */

static int      octsmi_iobus_match(device_t, struct cfdata *, void *);
static void     octsmi_iobus_attach(device_t, device_t, void *);

static int      octsmi_fdt_match(device_t, struct cfdata *, void *);
static void     octsmi_fdt_attach(device_t, device_t, void *);

static void     octsmi_attach_common(struct octsmi_softc *, int);

struct octsmi_instance {
        struct octsmi_softc *   sc;
        int                     phandle;
        TAILQ_ENTRY(octsmi_instance) next;
};

static TAILQ_HEAD(, octsmi_instance) octsmi_instances =
    TAILQ_HEAD_INITIALIZER(octsmi_instances);

#define _SMI_RD8(sc, off) \
        bus_space_read_8((sc)->sc_regt, (sc)->sc_regh, (off))
#define _SMI_WR8(sc, off, v) \
        bus_space_write_8((sc)->sc_regt, (sc)->sc_regh, (off), (v))

CFATTACH_DECL_NEW(octsmi_iobus, sizeof(struct octsmi_softc),
    octsmi_iobus_match, octsmi_iobus_attach, NULL, NULL);

CFATTACH_DECL_NEW(octsmi_fdt, sizeof(struct octsmi_softc),
    octsmi_fdt_match, octsmi_fdt_attach, NULL, NULL);

static const struct device_compatible_entry compat_data[] = {
        { .compat = "cavium,octeon-3860-mdio" },
        DEVICE_COMPAT_EOL
};

static int
octsmi_iobus_match(device_t parent, struct cfdata *cf, void *aux)
{
        struct iobus_attach_args *aa = aux;

        if (strcmp(cf->cf_name, aa->aa_name) != 0)
                return 0;
        if (aa->aa_unitno < SMI_NUNITS)
                return 1;
        else
                return 0;
}

static void
octsmi_iobus_attach(device_t parent, device_t self, void *aux)
{
        struct octsmi_softc *sc = device_private(self);
        struct iobus_attach_args *aa = aux;
        int status;

        sc->sc_dev = self;
        sc->sc_regt = aa->aa_bust;

        aprint_normal("\n");

        status = bus_space_map(sc->sc_regt, aa->aa_unit->addr, SMI_SIZE, 0,
            &sc->sc_regh);
        if (status != 0) {
                aprint_error_dev(self, "could not map registers\n");
                return;
        }

        octsmi_attach_common(sc, 0);
}

static int
octsmi_fdt_match(device_t parent, struct cfdata *cf, void *aux)
{
        struct fdt_attach_args * const faa = aux;

        return of_compatible_match(faa->faa_phandle, compat_data);
}

static void
octsmi_fdt_attach(device_t parent, device_t self, void *aux)
{
        struct octsmi_softc *sc = device_private(self);
        struct fdt_attach_args * const faa = aux;
        const int phandle = faa->faa_phandle;
        bus_addr_t addr;
        bus_size_t size;

        if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
                aprint_error(": couldn't get registers\n");
                return;
        }

        sc->sc_dev = self;
        sc->sc_regt = faa->faa_bst;

        if (bus_space_map(sc->sc_regt, addr, size, 0, &sc->sc_regh) != 0) {
                aprint_error(": couldn't map registers\n");
                return;
        }

        aprint_normal("\n");

        octsmi_attach_common(sc, phandle);
}

static void
octsmi_attach_common(struct octsmi_softc *sc, int phandle)
{
        struct octsmi_instance *oi;

        oi = kmem_alloc(sizeof(*oi), KM_SLEEP);
        oi->sc = sc;
        oi->phandle = phandle;
        TAILQ_INSERT_TAIL(&octsmi_instances, oi, next);

        const uint64_t magic_value =
            SMI_CLK_PREAMBLE |
            __SHIFTIN(0x4, SMI_CLK_SAMPLE) |            /* XXX magic 0x4 */
            __SHIFTIN(0x64, SMI_CLK_PHASE);             /* XXX magic 0x64 */
        _SMI_WR8(sc, SMI_CLK_OFFSET, magic_value);
        _SMI_WR8(sc, SMI_EN_OFFSET, SMI_EN_EN);
}

int
octsmi_read(struct octsmi_softc *sc, int phy_addr, int reg, uint16_t *val)
{
        uint64_t smi_rd;
        int timo;

        _SMI_WR8(sc, SMI_CMD_OFFSET,
            __SHIFTIN(SMI_CMD_PHY_OP_READ, SMI_CMD_PHY_OP) |
            __SHIFTIN(phy_addr, SMI_CMD_PHY_ADR) |
            __SHIFTIN(reg, SMI_CMD_REG_ADR));

        timo = 10000;
        smi_rd = _SMI_RD8(sc, SMI_RD_DAT_OFFSET);
        while (ISSET(smi_rd, SMI_RD_DAT_PENDING)) {
                if (timo-- == 0)
                        return ETIMEDOUT;
                delay(10);
                smi_rd = _SMI_RD8(sc, SMI_RD_DAT_OFFSET);
        }

        if (ISSET(smi_rd, SMI_RD_DAT_VAL)) {
                *val = (smi_rd & SMI_RD_DAT_DAT);
                return 0;
        }

        return -1;
}

int
octsmi_write(struct octsmi_softc *sc, int phy_addr, int reg, uint16_t value)
{
        uint64_t smi_wr;
        int timo;

        smi_wr = 0;
        SET(smi_wr, value);
        _SMI_WR8(sc, SMI_WR_DAT_OFFSET, smi_wr);

        _SMI_WR8(sc, SMI_CMD_OFFSET,
            __SHIFTIN(SMI_CMD_PHY_OP_WRITE, SMI_CMD_PHY_OP) |
            __SHIFTIN(phy_addr, SMI_CMD_PHY_ADR) |
            __SHIFTIN(reg, SMI_CMD_REG_ADR));

        timo = 10000;
        smi_wr = _SMI_RD8(sc, SMI_WR_DAT_OFFSET);
        while (ISSET(smi_wr, SMI_WR_DAT_PENDING)) {
                if (timo-- == 0) {
                        return ETIMEDOUT;
                }
                delay(10);
                smi_wr = _SMI_RD8(sc, SMI_WR_DAT_OFFSET);
        }
        if (ISSET(smi_wr, SMI_WR_DAT_PENDING)) {
                /* XXX log */
                printf("ERROR: octsmi_write(0x%x, 0x%x, 0x%hx) timed out.\n",
                    phy_addr, reg, value);
        }

        return 0;
}

struct octsmi_softc *
octsmi_lookup(int phandle, int port)
{
        struct octsmi_instance *oi;

#if notyet
        TAILQ_FOREACH(oi, &octsmi_instances, list) {
                if (oi->phandle == phandle)
                        return oi->sc;
        }

        return NULL;
#else
        oi = TAILQ_FIRST(&octsmi_instances);
        return oi == NULL ? NULL : oi->sc;
#endif
}