/*      $OpenBSD: gscpcib.c,v 1.8 2023/01/30 10:49:05 jsg Exp $ */
/*
 * Copyright (c) 2004 Alexander Yurchenko <grange@openbsd.org>
 *
 * 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.
 */

/*
 * Special driver for the National Semiconductor Geode SC1100 PCI-ISA bridge
 * that attaches instead of pcib(4). In addition to the core pcib(4)
 * functionality this driver provides support for the GPIO interface.
 */

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

#include <machine/bus.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>
#include <dev/pci/pcidevs.h>

#include <dev/gpio/gpiovar.h>

#include <i386/pci/gscpcibreg.h>

struct gscpcib_softc {
        struct device sc_dev;

        /* GPIO interface */
        bus_space_tag_t sc_gpio_iot;
        bus_space_handle_t sc_gpio_ioh;
        struct gpio_chipset_tag sc_gpio_gc;
        gpio_pin_t sc_gpio_pins[GSCGPIO_NPINS];
};

int     gscpcib_match(struct device *, void *, void *);
void    gscpcib_attach(struct device *, struct device *, void *);

int     gscpcib_gpio_pin_read(void *, int);
void    gscpcib_gpio_pin_write(void *, int, int);
void    gscpcib_gpio_pin_ctl(void *, int, int);

/* arch/i386/pci/pcib.c */
void    pcibattach(struct device *, struct device *, void *);

const struct cfattach gscpcib_ca = {
        sizeof (struct gscpcib_softc),
        gscpcib_match,
        gscpcib_attach
};

struct cfdriver gscpcib_cd = {
        NULL, "gscpcib", DV_DULL
};

int
gscpcib_match(struct device *parent, void *match, void *aux)
{
        struct pci_attach_args *pa = aux;

        if (PCI_CLASS(pa->pa_class) != PCI_CLASS_BRIDGE ||
            PCI_SUBCLASS(pa->pa_class) != PCI_SUBCLASS_BRIDGE_ISA)
                return (0);

        if (PCI_VENDOR(pa->pa_id) == PCI_VENDOR_NS &&
            PCI_PRODUCT(pa->pa_id) == PCI_PRODUCT_NS_SC1100_ISA)
                return (2);     /* supersede pcib(4) */

        return (0);
}

void
gscpcib_attach(struct device *parent, struct device *self, void *aux)
{
#ifndef SMALL_KERNEL
        struct gscpcib_softc *sc = (struct gscpcib_softc *)self;
        struct pci_attach_args *pa = aux;
        struct gpiobus_attach_args gba;
        pcireg_t gpiobase;
        int i;
        int gpio_present = 0;

        /* Map GPIO I/O space */
        gpiobase = pci_conf_read(pa->pa_pc, pa->pa_tag, GSCGPIO_BASE);
        sc->sc_gpio_iot = pa->pa_iot;
        if (PCI_MAPREG_IO_ADDR(gpiobase) == 0 ||
            bus_space_map(sc->sc_gpio_iot, PCI_MAPREG_IO_ADDR(gpiobase),
            GSCGPIO_SIZE, 0, &sc->sc_gpio_ioh)) {
                printf(": can't map GPIO i/o space");
                goto corepcib;
        }

        /* Initialize pins array */
        for (i = 0; i < GSCGPIO_NPINS; i++) {
                sc->sc_gpio_pins[i].pin_num = i;
                sc->sc_gpio_pins[i].pin_caps = GPIO_PIN_INPUT |
                    GPIO_PIN_OUTPUT | GPIO_PIN_OPENDRAIN |
                    GPIO_PIN_PUSHPULL | GPIO_PIN_TRISTATE |
                    GPIO_PIN_PULLUP;

                /* Read initial state */
                sc->sc_gpio_pins[i].pin_state = gscpcib_gpio_pin_read(sc, i) ?
                    GPIO_PIN_HIGH : GPIO_PIN_LOW;
        }

        /* Create controller tag */
        sc->sc_gpio_gc.gp_cookie = sc;
        sc->sc_gpio_gc.gp_pin_read = gscpcib_gpio_pin_read;
        sc->sc_gpio_gc.gp_pin_write = gscpcib_gpio_pin_write;
        sc->sc_gpio_gc.gp_pin_ctl = gscpcib_gpio_pin_ctl;

        gba.gba_name = "gpio";
        gba.gba_gc = &sc->sc_gpio_gc;
        gba.gba_pins = sc->sc_gpio_pins;
        gba.gba_npins = GSCGPIO_NPINS;

        gpio_present = 1;

corepcib:
#endif  /* !SMALL_KERNEL */
        /* Provide core pcib(4) functionality */
        pcibattach(parent, self, aux);

#ifndef SMALL_KERNEL
        /* Attach GPIO framework */
        if (gpio_present)
                config_found(&sc->sc_dev, &gba, gpiobus_print);
#endif  /* !SMALL_KERNEL */
}

#ifndef SMALL_KERNEL
static __inline void
gscpcib_gpio_pin_select(struct gscpcib_softc *sc, int pin)
{
        bus_space_write_4(sc->sc_gpio_iot, sc->sc_gpio_ioh, GSCGPIO_SEL, pin);
}

int
gscpcib_gpio_pin_read(void *arg, int pin)
{
        struct gscpcib_softc *sc = arg;
        int reg, shift;
        u_int32_t data;

        reg = (pin < 32 ? GSCGPIO_GPDI0 : GSCGPIO_GPDI1);
        shift = pin % 32;
        data = bus_space_read_4(sc->sc_gpio_iot, sc->sc_gpio_ioh, reg);

        return ((data >> shift) & 0x1);
}

void
gscpcib_gpio_pin_write(void *arg, int pin, int value)
{
        struct gscpcib_softc *sc = arg;
        int reg, shift;
        u_int32_t data;

        reg = (pin < 32 ? GSCGPIO_GPDO0 : GSCGPIO_GPDO1);
        shift = pin % 32;
        data = bus_space_read_4(sc->sc_gpio_iot, sc->sc_gpio_ioh, reg);
        if (value == 0)
                data &= ~(1 << shift);
        else if (value == 1)
                data |= (1 << shift);

        bus_space_write_4(sc->sc_gpio_iot, sc->sc_gpio_ioh, reg, data);
}

void
gscpcib_gpio_pin_ctl(void *arg, int pin, int flags)
{
        struct gscpcib_softc *sc = arg;
        u_int32_t conf;

        gscpcib_gpio_pin_select(sc, pin);
        conf = bus_space_read_4(sc->sc_gpio_iot, sc->sc_gpio_ioh,
            GSCGPIO_CONF);

        conf &= ~(GSCGPIO_CONF_OUTPUTEN | GSCGPIO_CONF_PUSHPULL |
            GSCGPIO_CONF_PULLUP);
        if ((flags & GPIO_PIN_TRISTATE) == 0)
                conf |= GSCGPIO_CONF_OUTPUTEN;
        if (flags & GPIO_PIN_PUSHPULL)
                conf |= GSCGPIO_CONF_PUSHPULL;
        if (flags & GPIO_PIN_PULLUP)
                conf |= GSCGPIO_CONF_PULLUP;
        bus_space_write_4(sc->sc_gpio_iot, sc->sc_gpio_ioh,
            GSCGPIO_CONF, conf);
}
#endif  /* !SMALL_KERNEL */