/*      $OpenBSD: pca9548.c,v 1.7 2024/05/13 01:15:50 jsg Exp $ */

/*
 * Copyright (c) 2020 Mark Kettenis
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>

#include <machine/bus.h>

#define _I2C_PRIVATE
#include <dev/i2c/i2cvar.h>

#ifdef __HAVE_ACPI
#include "acpi.h"
#endif

#if NACPI > 0
#include <dev/acpi/acpireg.h>
#include <dev/acpi/acpivar.h>
#include <dev/acpi/acpidev.h>
#include <dev/acpi/amltypes.h>
#include <dev/acpi/dsdt.h>
#endif

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_misc.h>

#define PCAMUX_MAX_CHANNELS     8

struct pcamux_bus {
        struct pcamux_softc     *pb_sc;
        int                     pb_node;
        void                    *pb_devnode;
        int                     pb_channel;
        struct i2c_controller   pb_ic;
        struct i2c_bus          pb_ib;
        struct device           *pb_iic;
};

struct pcamux_softc {
        struct device           sc_dev;
        i2c_tag_t               sc_tag;
        i2c_addr_t              sc_addr;

        int                     sc_node;
        void                    *sc_devnode;
        int                     sc_channel;
        int                     sc_nchannel;
        struct pcamux_bus       sc_bus[PCAMUX_MAX_CHANNELS];
        struct rwlock           sc_lock;

        int                     sc_switch;
        int                     sc_enable;
};

#if NACPI > 0
struct pcamux_crs {
        uint16_t i2c_addr;
        struct aml_node *devnode;
};
#endif

int     pcamux_match(struct device *, void *, void *);
void    pcamux_attach(struct device *, struct device *, void *);

const struct cfattach pcamux_ca = {
        sizeof(struct pcamux_softc), pcamux_match, pcamux_attach
};

struct cfdriver pcamux_cd = {
        NULL, "pcamux", DV_DULL
};

void    pcamux_attach_fdt(struct pcamux_softc *, struct i2c_attach_args *);
void    pcamux_attach_acpi(struct pcamux_softc *, struct i2c_attach_args *);

#if NACPI > 0
int     pcamux_attach_acpi_mux(struct aml_node *, void *);
void    pcamux_acpi_bus_scan(struct device *,
            struct i2cbus_attach_args *, void *);
int     pcamux_acpi_found_hid(struct aml_node *, void *);
int     pcamux_acpi_parse_crs(int, union acpi_resource *, void *);
#endif

int     pcamux_acquire_bus(void *, int);
void    pcamux_release_bus(void *, int);
int     pcamux_exec(void *, i2c_op_t, i2c_addr_t, const void *, size_t,
            void *, size_t, int);
void    pcamux_bus_scan(struct device *, struct i2cbus_attach_args *, void *);

int
pcamux_match(struct device *parent, void *match, void *aux)
{
        struct i2c_attach_args *ia = aux;

        if (strcmp(ia->ia_name, "nxp,pca9546") == 0 ||
            strcmp(ia->ia_name, "nxp,pca9547") == 0 ||
            strcmp(ia->ia_name, "nxp,pca9548") == 0 ||
            strcmp(ia->ia_name, "NXP0002") == 0)
                return (1);
        return (0);
}

void
pcamux_attach(struct device *parent, struct device *self, void *aux)
{
        struct pcamux_softc *sc = (struct pcamux_softc *)self;
        struct i2c_attach_args *ia = aux;

        sc->sc_tag = ia->ia_tag;
        sc->sc_addr = ia->ia_addr;

        sc->sc_channel = -1;    /* unknown */
        rw_init(&sc->sc_lock, sc->sc_dev.dv_xname);

        if (strcmp(ia->ia_name, "nxp,pca9546") == 0) {
                sc->sc_switch = 1;
                sc->sc_nchannel = 4;
        } else if (strcmp(ia->ia_name, "nxp,pca9547") == 0 ||
            strcmp(ia->ia_name, "NXP0002") == 0) {
                sc->sc_enable = 1 << 3;
                sc->sc_nchannel = 8;
        } else if (strcmp(ia->ia_name, "nxp,pca9548") == 0) {
                sc->sc_switch = 1;
                sc->sc_nchannel = 8;
        }

        printf("\n");

        if (strcmp(ia->ia_name, "NXP0002") == 0)
                pcamux_attach_acpi(sc, ia);
        else
                pcamux_attach_fdt(sc, ia);
}

void
pcamux_attach_fdt(struct pcamux_softc *sc, struct i2c_attach_args *ia)
{
        int node = *(int *)ia->ia_cookie;

        sc->sc_node = node;
        for (node = OF_child(node); node; node = OF_peer(node)) {
                struct i2cbus_attach_args iba;
                struct pcamux_bus *pb;
                uint32_t channel;

                channel = OF_getpropint(node, "reg", -1);
                if (channel >= sc->sc_nchannel)
                        continue;

                pb = &sc->sc_bus[channel];
                pb->pb_sc = sc;
                pb->pb_node = node;
                pb->pb_channel = channel;
                pb->pb_ic.ic_cookie = pb;
                pb->pb_ic.ic_acquire_bus = pcamux_acquire_bus;
                pb->pb_ic.ic_release_bus = pcamux_release_bus;
                pb->pb_ic.ic_exec = pcamux_exec;

                /* Configure the child busses. */
                memset(&iba, 0, sizeof(iba));
                iba.iba_name = "iic";
                iba.iba_tag = &pb->pb_ic;
                iba.iba_bus_scan = pcamux_bus_scan;
                iba.iba_bus_scan_arg = &pb->pb_node;

                config_found(&sc->sc_dev, &iba, iicbus_print);

                pb->pb_ib.ib_node = node;
                pb->pb_ib.ib_ic = &pb->pb_ic;
                i2c_register(&pb->pb_ib);
        }
}

void
pcamux_attach_acpi(struct pcamux_softc *sc, struct i2c_attach_args *ia)
{
#if NACPI > 0
        struct aml_node *node = ia->ia_cookie;

        sc->sc_devnode = node;
        aml_walknodes(node, AML_WALK_PRE, pcamux_attach_acpi_mux, sc);
#endif
}

#if NACPI > 0
int
pcamux_attach_acpi_mux(struct aml_node *node, void *arg)
{
        struct pcamux_softc *sc = arg;
        struct i2cbus_attach_args iba;
        struct pcamux_bus *pb;
        uint64_t channel;

        /* Only the node's direct children */
        if (node->parent != sc->sc_devnode)
                return 0;

        /* Must have channel as address */
        if (aml_evalinteger(acpi_softc, node, "_ADR", 0, NULL, &channel) ||
            channel >= sc->sc_nchannel)
                return 0;

        pb = &sc->sc_bus[channel];
        pb->pb_sc = sc;
        pb->pb_devnode = node;
        pb->pb_channel = channel;
        pb->pb_ic.ic_cookie = pb;
        pb->pb_ic.ic_acquire_bus = pcamux_acquire_bus;
        pb->pb_ic.ic_release_bus = pcamux_release_bus;
        pb->pb_ic.ic_exec = pcamux_exec;

        /* Configure the child busses. */
        memset(&iba, 0, sizeof(iba));
        iba.iba_name = "iic";
        iba.iba_tag = &pb->pb_ic;
        iba.iba_bus_scan = pcamux_acpi_bus_scan;
        iba.iba_bus_scan_arg = pb;

        config_found(&sc->sc_dev, &iba, iicbus_print);

#ifndef SMALL_KERNEL
        node->i2c = &pb->pb_ic;
        acpi_register_gsb(acpi_softc, node);
#endif
        return 0;
}

void
pcamux_acpi_bus_scan(struct device *iic, struct i2cbus_attach_args *iba,
    void *aux)
{
        struct pcamux_bus *pb = aux;

        pb->pb_iic = iic;
        aml_find_node(pb->pb_devnode, "_HID", pcamux_acpi_found_hid, aux);
}

int
pcamux_acpi_found_hid(struct aml_node *node, void *arg)
{
        struct pcamux_bus *pb = arg;
        struct pcamux_softc *sc = pb->pb_sc;
        struct pcamux_crs crs;
        struct aml_value res;
        int64_t sta;
        char cdev[16], dev[16];
        struct i2c_attach_args ia;

        /* Skip our own _HID. */
        if (node->parent == pb->pb_devnode)
                return 0;

        /* Only direct descendants, because of possible muxes. */
        if (node->parent && node->parent->parent != pb->pb_devnode)
                return 0;

        if (acpi_parsehid(node, arg, cdev, dev, 16) != 0)
                return 0;

        sta = acpi_getsta(acpi_softc, node->parent);
        if ((sta & STA_PRESENT) == 0)
                return 0;

        if (aml_evalname(acpi_softc, node->parent, "_CRS", 0, NULL, &res))
                return 0;

        if (res.type != AML_OBJTYPE_BUFFER || res.length < 5) {
                printf("%s: invalid _CRS object (type %d len %d)\n",
                    sc->sc_dev.dv_xname, res.type, res.length);
                aml_freevalue(&res);
                return (0);
        }
        memset(&crs, 0, sizeof(crs));
        crs.devnode = sc->sc_devnode;
        aml_parse_resource(&res, pcamux_acpi_parse_crs, &crs);
        aml_freevalue(&res);

        acpi_attach_deps(acpi_softc, node->parent);

        memset(&ia, 0, sizeof(ia));
        ia.ia_tag = &pb->pb_ic;
        ia.ia_name = dev;
        ia.ia_addr = crs.i2c_addr;
        ia.ia_cookie = node->parent;

        config_found(pb->pb_iic, &ia, iic_print);
        node->parent->attached = 1;

        return 0;
}

int
pcamux_acpi_parse_crs(int crsidx, union acpi_resource *crs, void *arg)
{
        struct pcamux_crs *sc_crs = arg;

        switch (AML_CRSTYPE(crs)) {
        case LR_SERBUS:
                if (crs->lr_serbus.type == LR_SERBUS_I2C)
                        sc_crs->i2c_addr = crs->lr_i2cbus._adr;
                break;

        default:
                printf("%s: unknown resource type %d\n", __func__,
                    AML_CRSTYPE(crs));
        }

        return 0;
}
#endif

int
pcamux_set_channel(struct pcamux_softc *sc, int channel, int flags)
{
        uint8_t data;
        int error;

        if (channel < -1 || channel >= sc->sc_nchannel)
                return ENXIO;

        if (sc->sc_channel == channel)
                return 0;

        data = 0;
        if (channel != -1) {
                if (sc->sc_switch)
                        data = 1 << channel;
                else
                        data = sc->sc_enable | channel;
        }
        error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
            sc->sc_addr, NULL, 0, &data, sizeof data, flags);

        return error;
}

int
pcamux_acquire_bus(void *cookie, int flags)
{
        struct pcamux_bus *pb = cookie;
        struct pcamux_softc *sc = pb->pb_sc;
        int rwflags = RW_WRITE;
        int error;

        if (flags & I2C_F_POLL)
                rwflags |= RW_NOSLEEP;

        error = rw_enter(&sc->sc_lock, rwflags);
        if (error)
                return error;

        /* Acquire parent bus. */
        error = iic_acquire_bus(sc->sc_tag, flags);
        if (error) {
                rw_exit_write(&sc->sc_lock);
                return error;
        }

        error = pcamux_set_channel(sc, pb->pb_channel, flags);
        if (error) {
                iic_release_bus(sc->sc_tag, flags);
                rw_exit_write(&sc->sc_lock);
                return error;
        }

        return 0;
}

void
pcamux_release_bus(void *cookie, int flags)
{
        struct pcamux_bus *pb = cookie;
        struct pcamux_softc *sc = pb->pb_sc;

        /* Release parent bus. */
        iic_release_bus(sc->sc_tag, flags);
        rw_exit_write(&sc->sc_lock);
}

int
pcamux_exec(void *cookie, i2c_op_t op, i2c_addr_t addr, const void *cmd,
    size_t cmdlen, void *buf, size_t buflen, int flags)
{
        struct pcamux_bus *pb = cookie;
        struct pcamux_softc *sc = pb->pb_sc;

        rw_assert_wrlock(&sc->sc_lock);

        /* Issue the transaction on the parent bus. */
        return iic_exec(sc->sc_tag, op, addr, cmd, cmdlen, buf, buflen, flags);
}

void
pcamux_bus_scan(struct device *self, struct i2cbus_attach_args *iba, void *arg)
{
        int iba_node = *(int *)arg;
        struct i2c_attach_args ia;
        char name[32];
        uint32_t reg[1];
        int node;

        for (node = OF_child(iba_node); node; node = OF_peer(node)) {
                memset(name, 0, sizeof(name));
                memset(reg, 0, sizeof(reg));

                if (OF_getprop(node, "compatible", name, sizeof(name)) == -1)
                        continue;
                if (name[0] == '\0')
                        continue;

                if (OF_getprop(node, "reg", &reg, sizeof(reg)) != sizeof(reg))
                        continue;

                memset(&ia, 0, sizeof(ia));
                ia.ia_tag = iba->iba_tag;
                ia.ia_addr = bemtoh32(&reg[0]);
                ia.ia_name = name;
                ia.ia_cookie = &node;
                config_found(self, &ia, iic_print);
        }
}