/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009, Oleksandr Tymoshenko <gonzo@FreeBSD.org>
 * Copyright (c) 2009, Luiz Otavio O Souza. 
 * 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 unmodified, 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 AUTHOR 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 AUTHOR 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.
 */

/*
 * GPIO driver for AR71xx 
 */

#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>

#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/gpio.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <mips/atheros/ar71xxreg.h>
#include <mips/atheros/ar71xx_setup.h>
#include <mips/atheros/ar71xx_cpudef.h>
#include <mips/atheros/ar71xx_gpiovar.h>
#include <dev/gpio/gpiobusvar.h>
#include <mips/atheros/ar933xreg.h>
#include <mips/atheros/ar934xreg.h>
#include <mips/atheros/qca953xreg.h>
#include <mips/atheros/qca955xreg.h>

#include "gpio_if.h"

#define	DEFAULT_CAPS	(GPIO_PIN_INPUT | GPIO_PIN_OUTPUT)

/*
 * Helpers
 */
static void ar71xx_gpio_function_enable(struct ar71xx_gpio_softc *sc, 
    uint32_t mask);
static void ar71xx_gpio_function_disable(struct ar71xx_gpio_softc *sc, 
    uint32_t mask);
static void ar71xx_gpio_pin_configure(struct ar71xx_gpio_softc *sc, 
    struct gpio_pin *pin, uint32_t flags);

/*
 * Driver stuff
 */
static int ar71xx_gpio_probe(device_t dev);
static int ar71xx_gpio_attach(device_t dev);
static int ar71xx_gpio_detach(device_t dev);
static int ar71xx_gpio_filter(void *arg);
static void ar71xx_gpio_intr(void *arg);

/*
 * GPIO interface
 */
static device_t ar71xx_gpio_get_bus(device_t);
static int ar71xx_gpio_pin_max(device_t dev, int *maxpin);
static int ar71xx_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps);
static int ar71xx_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t
    *flags);
static int ar71xx_gpio_pin_getname(device_t dev, uint32_t pin, char *name);
static int ar71xx_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags);
static int ar71xx_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value);
static int ar71xx_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val);
static int ar71xx_gpio_pin_toggle(device_t dev, uint32_t pin);

/*
 * Enable/disable the GPIO function control space.
 *
 * This is primarily for the AR71xx, which has SPI CS1/CS2, UART, SLIC, I2S
 * as GPIO pin options.
 */
static void
ar71xx_gpio_function_enable(struct ar71xx_gpio_softc *sc, uint32_t mask)
{

	/*
	 * XXX TODO: refactor this out into a per-chipset method.
	 */
	if (ar71xx_soc == AR71XX_SOC_AR9341 ||
	    ar71xx_soc == AR71XX_SOC_AR9342 ||
	    ar71xx_soc == AR71XX_SOC_AR9344 ||
	    ar71xx_soc == AR71XX_SOC_QCA9533 ||
	    ar71xx_soc == AR71XX_SOC_QCA9533_V2 ||
	    ar71xx_soc == AR71XX_SOC_QCA9556 ||
	    ar71xx_soc == AR71XX_SOC_QCA9558)
		GPIO_SET_BITS(sc, AR934X_GPIO_REG_FUNC, mask);
	else
		GPIO_SET_BITS(sc, AR71XX_GPIO_FUNCTION, mask);
}

static void
ar71xx_gpio_function_disable(struct ar71xx_gpio_softc *sc, uint32_t mask)
{

	/*
	 * XXX TODO: refactor this out into a per-chipset method.
	 */
	if (ar71xx_soc == AR71XX_SOC_AR9341 ||
	    ar71xx_soc == AR71XX_SOC_AR9342 ||
	    ar71xx_soc == AR71XX_SOC_AR9344 ||
	    ar71xx_soc == AR71XX_SOC_QCA9533 ||
	    ar71xx_soc == AR71XX_SOC_QCA9533_V2 ||
	    ar71xx_soc == AR71XX_SOC_QCA9556 ||
	    ar71xx_soc == AR71XX_SOC_QCA9558)
		GPIO_CLEAR_BITS(sc, AR934X_GPIO_REG_FUNC, mask);
	else
		GPIO_CLEAR_BITS(sc, AR71XX_GPIO_FUNCTION, mask);
}

/*
 * On most platforms, GPIO_OE is a bitmap where the bit set
 * means "enable output."
 *
 * On AR934x and QCA953x, it's the opposite - the bit set means
 * "input enable".
 */
static int
ar71xx_gpio_oe_is_high(void)
{
	switch (ar71xx_soc) {
	case AR71XX_SOC_AR9341:
	case AR71XX_SOC_AR9342:
	case AR71XX_SOC_AR9344:
	case AR71XX_SOC_QCA9533:
	case AR71XX_SOC_QCA9533_V2:
		return 0;
	default:
		return 1;
	}
}

static void
ar71xx_gpio_oe_set_output(struct ar71xx_gpio_softc *sc, int b)
{
	uint32_t mask;

	mask = 1 << b;

	if (ar71xx_gpio_oe_is_high())
		GPIO_SET_BITS(sc, AR71XX_GPIO_OE, mask);
	else
		GPIO_CLEAR_BITS(sc, AR71XX_GPIO_OE, mask);
}

static void
ar71xx_gpio_oe_set_input(struct ar71xx_gpio_softc *sc, int b)
{
	uint32_t mask;

	mask = 1 << b;

	if (ar71xx_gpio_oe_is_high())
		GPIO_CLEAR_BITS(sc, AR71XX_GPIO_OE, mask);
	else
		GPIO_SET_BITS(sc, AR71XX_GPIO_OE, mask);
}

static void
ar71xx_gpio_pin_configure(struct ar71xx_gpio_softc *sc, struct gpio_pin *pin,
    unsigned int flags)
{

	/*
	 * Manage input/output
	 */
	if (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
		pin->gp_flags &= ~(GPIO_PIN_INPUT|GPIO_PIN_OUTPUT);
		if (flags & GPIO_PIN_OUTPUT) {
			pin->gp_flags |= GPIO_PIN_OUTPUT;
			ar71xx_gpio_oe_set_output(sc, pin->gp_pin);
		} else {
			pin->gp_flags |= GPIO_PIN_INPUT;
			ar71xx_gpio_oe_set_input(sc, pin->gp_pin);
		}
	}
}

static device_t
ar71xx_gpio_get_bus(device_t dev)
{
	struct ar71xx_gpio_softc *sc;

	sc = device_get_softc(dev);

	return (sc->busdev);
}

static int
ar71xx_gpio_pin_max(device_t dev, int *maxpin)
{

	switch (ar71xx_soc) {
		case AR71XX_SOC_AR9130:
		case AR71XX_SOC_AR9132:
			*maxpin = AR91XX_GPIO_PINS - 1;
			break;
		case AR71XX_SOC_AR7240:
		case AR71XX_SOC_AR7242:
			*maxpin = AR724X_GPIO_PINS - 1;
			break;
		case AR71XX_SOC_AR7241:
			*maxpin = AR7241_GPIO_PINS - 1;
			break;
		case AR71XX_SOC_AR9330:
		case AR71XX_SOC_AR9331:
			*maxpin = AR933X_GPIO_COUNT - 1;
			break;
		case AR71XX_SOC_AR9341:
		case AR71XX_SOC_AR9342:
		case AR71XX_SOC_AR9344:
			*maxpin = AR934X_GPIO_COUNT - 1;
			break;
		case AR71XX_SOC_QCA9533:
		case AR71XX_SOC_QCA9533_V2:
			*maxpin = QCA953X_GPIO_COUNT - 1;
			break;
		case AR71XX_SOC_QCA9556:
		case AR71XX_SOC_QCA9558:
			*maxpin = QCA955X_GPIO_COUNT - 1;
			break;
		default:
			*maxpin = AR71XX_GPIO_PINS - 1;
	}
	return (0);
}

static int
ar71xx_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
{
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);
	int i;

	for (i = 0; i < sc->gpio_npins; i++) {
		if (sc->gpio_pins[i].gp_pin == pin)
			break;
	}

	if (i >= sc->gpio_npins)
		return (EINVAL);

	GPIO_LOCK(sc);
	*caps = sc->gpio_pins[i].gp_caps;
	GPIO_UNLOCK(sc);

	return (0);
}

static int
ar71xx_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
{
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);
	int i;

	for (i = 0; i < sc->gpio_npins; i++) {
		if (sc->gpio_pins[i].gp_pin == pin)
			break;
	}

	if (i >= sc->gpio_npins)
		return (EINVAL);

	GPIO_LOCK(sc);
	*flags = sc->gpio_pins[i].gp_flags;
	GPIO_UNLOCK(sc);

	return (0);
}

static int
ar71xx_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
{
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);
	int i;

	for (i = 0; i < sc->gpio_npins; i++) {
		if (sc->gpio_pins[i].gp_pin == pin)
			break;
	}

	if (i >= sc->gpio_npins)
		return (EINVAL);

	GPIO_LOCK(sc);
	memcpy(name, sc->gpio_pins[i].gp_name, GPIOMAXNAME);
	GPIO_UNLOCK(sc);

	return (0);
}

static int
ar71xx_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
{
	int i;
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);

	for (i = 0; i < sc->gpio_npins; i++) {
		if (sc->gpio_pins[i].gp_pin == pin)
			break;
	}

	if (i >= sc->gpio_npins)
		return (EINVAL);

	ar71xx_gpio_pin_configure(sc, &sc->gpio_pins[i], flags);

	return (0);
}

static int
ar71xx_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
{
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);
	int i;

	for (i = 0; i < sc->gpio_npins; i++) {
		if (sc->gpio_pins[i].gp_pin == pin)
			break;
	}

	if (i >= sc->gpio_npins)
		return (EINVAL);

	if (value)
		GPIO_WRITE(sc, AR71XX_GPIO_SET, (1 << pin));
	else
		GPIO_WRITE(sc, AR71XX_GPIO_CLEAR, (1 << pin));

	return (0);
}

static int
ar71xx_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
{
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);
	int i;

	for (i = 0; i < sc->gpio_npins; i++) {
		if (sc->gpio_pins[i].gp_pin == pin)
			break;
	}

	if (i >= sc->gpio_npins)
		return (EINVAL);

	*val = (GPIO_READ(sc, AR71XX_GPIO_IN) & (1 << pin)) ? 1 : 0;

	return (0);
}

static int
ar71xx_gpio_pin_toggle(device_t dev, uint32_t pin)
{
	int res, i;
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);

	for (i = 0; i < sc->gpio_npins; i++) {
		if (sc->gpio_pins[i].gp_pin == pin)
			break;
	}

	if (i >= sc->gpio_npins)
		return (EINVAL);

	res = (GPIO_READ(sc, AR71XX_GPIO_IN) & (1 << pin)) ? 1 : 0;
	if (res)
		GPIO_WRITE(sc, AR71XX_GPIO_CLEAR, (1 << pin));
	else
		GPIO_WRITE(sc, AR71XX_GPIO_SET, (1 << pin));

	return (0);
}

static int
ar71xx_gpio_filter(void *arg)
{

	/* TODO: something useful */
	return (FILTER_STRAY);
}

static void
ar71xx_gpio_intr(void *arg)
{
	struct ar71xx_gpio_softc *sc = arg;
	GPIO_LOCK(sc);
	/* TODO: something useful */
	GPIO_UNLOCK(sc);
}

static int
ar71xx_gpio_probe(device_t dev)
{

	device_set_desc(dev, "Atheros AR71XX GPIO driver");
	return (0);
}

static int
ar71xx_gpio_attach(device_t dev)
{
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);
	int i, j, maxpin;
	int mask, pinon;
	uint32_t oe;

	KASSERT((device_get_unit(dev) == 0),
	    ("ar71xx_gpio: Only one gpio module supported"));

	mtx_init(&sc->gpio_mtx, device_get_nameunit(dev), NULL, MTX_DEF);

	/* Map control/status registers. */
	sc->gpio_mem_rid = 0;
	sc->gpio_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
	    &sc->gpio_mem_rid, RF_ACTIVE);

	if (sc->gpio_mem_res == NULL) {
		device_printf(dev, "couldn't map memory\n");
		ar71xx_gpio_detach(dev);
		return (ENXIO);
	}

	if ((sc->gpio_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, 
	    &sc->gpio_irq_rid, RF_SHAREABLE | RF_ACTIVE)) == NULL) {
		device_printf(dev, "unable to allocate IRQ resource\n");
		ar71xx_gpio_detach(dev);
		return (ENXIO);
	}

	if ((bus_setup_intr(dev, sc->gpio_irq_res, INTR_TYPE_MISC, 
	    ar71xx_gpio_filter, ar71xx_gpio_intr, sc, &sc->gpio_ih))) {
		device_printf(dev,
		    "WARNING: unable to register interrupt handler\n");
		ar71xx_gpio_detach(dev);
		return (ENXIO);
	}

	sc->dev = dev;

	/* Enable function bits that are required */
	if (resource_int_value(device_get_name(dev), device_get_unit(dev),
	    "function_set", &mask) == 0) {
		device_printf(dev, "function_set: 0x%x\n", mask);
		ar71xx_gpio_function_enable(sc, mask);
	}
	/* Disable function bits that are required */
	if (resource_int_value(device_get_name(dev), device_get_unit(dev),
	    "function_clear", &mask) == 0) {
		device_printf(dev, "function_clear: 0x%x\n", mask);
		ar71xx_gpio_function_disable(sc, mask);
	}

	/* Disable interrupts for all pins. */
	GPIO_WRITE(sc, AR71XX_GPIO_INT_MASK, 0);

	/* Initialise all pins specified in the mask, up to the pin count */
	(void) ar71xx_gpio_pin_max(dev, &maxpin);
	if (resource_int_value(device_get_name(dev), device_get_unit(dev),
	    "pinmask", &mask) != 0)
		mask = 0;
	if (resource_int_value(device_get_name(dev), device_get_unit(dev),
	    "pinon", &pinon) != 0)
		pinon = 0;
	device_printf(dev, "gpio pinmask=0x%x\n", mask);
	for (j = 0; j <= maxpin; j++) {
		if ((mask & (1 << j)) == 0)
			continue;
		sc->gpio_npins++;
	}
	/* Iniatilize the GPIO pins, keep the loader settings. */
	oe = GPIO_READ(sc, AR71XX_GPIO_OE);
	/*
	 * For AR934x and QCA953x, the meaning of oe is inverted;
	 * so flip it the right way around so we can parse the GPIO
	 * state.
	 */
	if (!ar71xx_gpio_oe_is_high())
		oe = ~oe;

	sc->gpio_pins = malloc(sizeof(*sc->gpio_pins) * sc->gpio_npins,
	    M_DEVBUF, M_WAITOK | M_ZERO);
	for (i = 0, j = 0; j <= maxpin; j++) {
		if ((mask & (1 << j)) == 0)
			continue;
		snprintf(sc->gpio_pins[i].gp_name, GPIOMAXNAME,
		    "pin %d", j);
		sc->gpio_pins[i].gp_pin = j;
		sc->gpio_pins[i].gp_caps = DEFAULT_CAPS;
		if (oe & (1 << j))
			sc->gpio_pins[i].gp_flags = GPIO_PIN_OUTPUT;
		else
			sc->gpio_pins[i].gp_flags = GPIO_PIN_INPUT;
		i++;
	}

	/* Turn on the hinted pins. */
	for (i = 0; i < sc->gpio_npins; i++) {
		j = sc->gpio_pins[i].gp_pin;
		if ((pinon & (1 << j)) != 0) {
			ar71xx_gpio_pin_setflags(dev, j, GPIO_PIN_OUTPUT);
			ar71xx_gpio_pin_set(dev, j, 1);
		}
	}

	/*
	 * Search through the function hints, in case there's some
	 * overrides such as LNA control.
	 *
	 * hint.gpio.X.func.<pin>.gpiofunc=<func value>
	 * hint.gpio.X.func.<pin>.gpiomode=1 (for output, default low)
	 */
	for (i = 0; i <= maxpin; i++) {
		char buf[32];
		int gpiofunc, gpiomode;

		snprintf(buf, 32, "func.%d.gpiofunc", i);
		if (resource_int_value(device_get_name(dev),
		    device_get_unit(dev),
		    buf,
		    &gpiofunc) != 0)
			continue;
		/* Get the mode too */
		snprintf(buf, 32, "func.%d.gpiomode", i);
		if (resource_int_value(device_get_name(dev),
		    device_get_unit(dev),
		    buf,
		    &gpiomode) != 0)
			continue;

		/* We only handle mode=1 (output) for now */
		if (gpiomode != 1)
			continue;

		device_printf(dev, "%s: GPIO %d: func=%d, mode=%d\n",
		    __func__,
		    i,
		    gpiofunc,
		    gpiomode);

		/* Set pin value = 0, so it stays low by default */
		oe = GPIO_READ(sc, AR71XX_GPIO_OUT);
		oe &= ~ (1 << i);
		GPIO_WRITE(sc, AR71XX_GPIO_OUT, oe);

		/* Set output */
		ar71xx_gpio_oe_set_output(sc, i);

		/* Finally: Set the output config */
		ar71xx_gpio_ouput_configure(i, gpiofunc);
	}

	sc->busdev = gpiobus_attach_bus(dev);
	if (sc->busdev == NULL) {
		ar71xx_gpio_detach(dev);
		return (ENXIO);
	}

	return (0);
}

static int
ar71xx_gpio_detach(device_t dev)
{
	struct ar71xx_gpio_softc *sc = device_get_softc(dev);

	KASSERT(mtx_initialized(&sc->gpio_mtx), ("gpio mutex not initialized"));

	gpiobus_detach_bus(dev);
	if (sc->gpio_ih)
		bus_teardown_intr(dev, sc->gpio_irq_res, sc->gpio_ih);
	if (sc->gpio_irq_res)
		bus_release_resource(dev, SYS_RES_IRQ, sc->gpio_irq_rid,
		    sc->gpio_irq_res);
	if (sc->gpio_mem_res)
		bus_release_resource(dev, SYS_RES_MEMORY, sc->gpio_mem_rid,
		    sc->gpio_mem_res);
	if (sc->gpio_pins)
		free(sc->gpio_pins, M_DEVBUF);
	mtx_destroy(&sc->gpio_mtx);

	return(0);
}

static device_method_t ar71xx_gpio_methods[] = {
	DEVMETHOD(device_probe, ar71xx_gpio_probe),
	DEVMETHOD(device_attach, ar71xx_gpio_attach),
	DEVMETHOD(device_detach, ar71xx_gpio_detach),

	/* GPIO protocol */
	DEVMETHOD(gpio_get_bus, ar71xx_gpio_get_bus),
	DEVMETHOD(gpio_pin_max, ar71xx_gpio_pin_max),
	DEVMETHOD(gpio_pin_getname, ar71xx_gpio_pin_getname),
	DEVMETHOD(gpio_pin_getflags, ar71xx_gpio_pin_getflags),
	DEVMETHOD(gpio_pin_getcaps, ar71xx_gpio_pin_getcaps),
	DEVMETHOD(gpio_pin_setflags, ar71xx_gpio_pin_setflags),
	DEVMETHOD(gpio_pin_get, ar71xx_gpio_pin_get),
	DEVMETHOD(gpio_pin_set, ar71xx_gpio_pin_set),
	DEVMETHOD(gpio_pin_toggle, ar71xx_gpio_pin_toggle),
	{0, 0},
};

static driver_t ar71xx_gpio_driver = {
	"gpio",
	ar71xx_gpio_methods,
	sizeof(struct ar71xx_gpio_softc),
};
static devclass_t ar71xx_gpio_devclass;

DRIVER_MODULE(ar71xx_gpio, apb, ar71xx_gpio_driver, ar71xx_gpio_devclass, 0, 0);