/*	$NetBSD: apple_pinctrl.c,v 1.1 2022/04/27 07:59:18 skrll Exp $	*/
/*	$OpenBSD: aplpinctrl.c,v 1.4 2022/04/06 18:59:26 naddy Exp $	*/

/*-
 * Copyright (c) 2022 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Nick Hudson
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Copyright (c) 2021 Mark Kettenis <kettenis@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.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: apple_pinctrl.c,v 1.1 2022/04/27 07:59:18 skrll Exp $");

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

#include <dev/fdt/fdtvar.h>

#include <arm/pic/picvar.h>

#define APPLE_PIN(pinmux)	__SHIFTOUT((pinmux), __BITS(15, 0))
#define APPLE_FUNC(pinmux)	__SHIFTOUT((pinmux), __BITS(31, 16))

#define GPIO_PIN(pin)		((pin) * 4)
#define  GPIO_PIN_GROUP_MASK	__BITS(18, 16)
#define  GPIO_PIN_INPUT_ENABLE	__BIT(9)
#define  GPIO_PIN_FUNC_MASK	__BITS(6, 5)
#define  GPIO_PIN_MODE_MASK	__BITS(3, 1)
#define  GPIO_PIN_MODE_INPUT	 __SHIFTIN(0, GPIO_PIN_MODE_MASK);
#define  GPIO_PIN_MODE_OUTPUT	 __SHIFTIN(1, GPIO_PIN_MODE_MASK);
#define  GPIO_PIN_MODE_IRQ_HI	 __SHIFTIN(2, GPIO_PIN_MODE_MASK);
#define  GPIO_PIN_MODE_IRQ_LO	 __SHIFTIN(3, GPIO_PIN_MODE_MASK);
#define  GPIO_PIN_MODE_IRQ_UP	 __SHIFTIN(4, GPIO_PIN_MODE_MASK);
#define  GPIO_PIN_MODE_IRQ_DN	 __SHIFTIN(5, GPIO_PIN_MODE_MASK);
#define  GPIO_PIN_MODE_IRQ_ANY	 __SHIFTIN(6, GPIO_PIN_MODE_MASK);
#define  GPIO_PIN_MODE_IRQ_OFF	 __SHIFTIN(7, GPIO_PIN_MODE_MASK);
#define  GPIO_PIN_DATA		__BIT(0)
#define GPIO_IRQ(grp, pin)	(0x800 + (grp) * 64 + ((pin) >> 5) * 4)

#define PINCTRL_READ(sc, reg)						\
	(bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg)))
#define PINCTRL_WRITE(sc, reg, val)					\
	bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
#define PINCTRL_SET(sc, reg, bits)					\
	PINCTRL_WRITE((sc), (reg), PINCTRL_READ((sc), (reg)) | (bits))
#define PINCTRL_CLR(sc, reg, bits)					\
	PINCTRL_WRITE((sc), (reg), PINCTRL_READ((sc), (reg)) & ~(bits))


struct apple_pinctrl_softc {
	device_t sc_dev;
	int sc_phandle;
	bus_space_tag_t sc_bst;
	bus_space_handle_t sc_bsh;
	u_int sc_npins;
};

struct apple_gpio_pin {
	int		pin_no;
	u_int		pin_flags;
	bool		pin_actlo;
};

static const struct device_compatible_entry compat_data[] = {
	{ .compat = "apple,pinctrl" },
	DEVICE_COMPAT_EOL
};

static void
apple_gpio_pin_ctl(void *cookie, int pin, int flags)
{
	struct apple_pinctrl_softc * const sc = cookie;

	KASSERT(pin < sc->sc_npins);

	uint32_t reg = PINCTRL_READ(sc, GPIO_PIN(pin));
	reg &= ~GPIO_PIN_FUNC_MASK;
	reg &= ~GPIO_PIN_MODE_MASK;

	if (flags & (GPIO_PIN_OUTPUT | GPIO_PIN_INPUT)) {
		if (flags & GPIO_PIN_INPUT) {
			/* for safety INPUT will override output */
			reg |= GPIO_PIN_MODE_INPUT;
		} else {
			reg |= GPIO_PIN_MODE_OUTPUT;
		}
	}
	PINCTRL_WRITE(sc, GPIO_PIN(pin), reg);
}

static void *
apple_pinctrl_gpio_acquire(device_t dev, const void *data, size_t len, int flags)
{
	struct apple_pinctrl_softc * const sc = device_private(dev);
	struct apple_gpio_pin *pin;
	const u_int *gpio = data;

	if (len != 12)
		return NULL;

	const u_int pinno = be32toh(gpio[1]);
	const bool actlo = be32toh(gpio[2]) & 1;

	if (pinno >= sc->sc_npins)
		return NULL;

	pin = kmem_alloc(sizeof(*pin), KM_SLEEP);
	pin->pin_no = pinno;
	pin->pin_flags = flags;
	pin->pin_actlo = actlo;

	apple_gpio_pin_ctl(sc, pin->pin_no, pin->pin_flags);

	return pin;
}

static void
apple_pinctrl_gpio_release(device_t dev, void *priv)
{
	struct apple_pinctrl_softc * const sc = device_private(dev);
	struct apple_gpio_pin *pin = priv;

	apple_gpio_pin_ctl(sc, pin->pin_no, GPIO_PIN_INPUT);
	kmem_free(pin, sizeof(*pin));
}

static int
apple_pinctrl_gpio_read(device_t dev, void *priv, bool raw)
{
	struct apple_pinctrl_softc * const sc = device_private(dev);
	struct apple_gpio_pin *pin = priv;

	KASSERT(pin->pin_no < sc->sc_npins);

	uint32_t reg = PINCTRL_READ(sc, GPIO_PIN(pin->pin_no));
	int val = __SHIFTOUT(reg, GPIO_PIN_DATA);
	if (!raw && pin->pin_actlo)
		val = !val;

	return val;
}

static void
apple_pinctrl_gpio_write(device_t dev, void *priv, int val, bool raw)
{
	struct apple_pinctrl_softc * const sc = device_private(dev);
	struct apple_gpio_pin *pin = priv;

	KASSERT(pin->pin_no < sc->sc_npins);

	if (!raw && pin->pin_actlo)
		val = !val;

	if (val)
		PINCTRL_SET(sc, GPIO_PIN(pin->pin_no), GPIO_PIN_DATA);
	else
		PINCTRL_CLR(sc, GPIO_PIN(pin->pin_no), GPIO_PIN_DATA);
}

static int
apple_pinctrl_set_config(device_t dev, const void *data, size_t len)
{
	struct apple_pinctrl_softc * const sc = device_private(dev);

	if (len != 4)
		return -1;

	int pins_len;
	const int phandle = fdtbus_get_phandle_from_native(be32dec(data));
	const u_int *pins = fdtbus_get_prop(phandle, "pinmux", &pins_len);

	if (pins == NULL)
		return -1;

	const u_int npins = pins_len / sizeof(uint32_t);

	for (u_int i = 0; i < npins; i++) {
		uint32_t pinmux = be32dec(&pins[i]);
		u_int pinno = APPLE_PIN(pinmux);
		u_int func = APPLE_FUNC(pinmux);

		uint32_t reg = PINCTRL_READ(sc, GPIO_PIN(pinno));
		reg &= ~GPIO_PIN_FUNC_MASK;
		reg |= __SHIFTIN(func, GPIO_PIN_FUNC_MASK);

		PINCTRL_WRITE(sc, GPIO_PIN(pinno), reg);
	}

	return 0;
}

static struct fdtbus_gpio_controller_func apple_pinctrl_gpio_funcs = {
	.acquire = apple_pinctrl_gpio_acquire,
	.release = apple_pinctrl_gpio_release,
	.read = apple_pinctrl_gpio_read,
	.write = apple_pinctrl_gpio_write
};

static struct fdtbus_pinctrl_controller_func apple_pinctrl_funcs = {
	.set_config = apple_pinctrl_set_config,
};

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

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

static void
apple_pinctrl_attach(device_t parent, device_t self, void *aux)
{
	struct apple_pinctrl_softc * const 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_bst = faa->faa_bst;

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

	if (of_getprop_uint32(phandle, "apple,npins", &sc->sc_npins)) {
		aprint_error(": couldn't get number of pins\n");
		return;
	}

	if (!of_hasprop(phandle, "gpio-controller")) {
		aprint_error(": no gpio controller");
		return;
	}

	aprint_naive("\n");
	aprint_normal(": Apple Pinctrl\n");

	fdtbus_register_gpio_controller(self, phandle, &apple_pinctrl_gpio_funcs);

	for (int child = OF_child(phandle); child; child = OF_peer(child)) {
		if (!of_hasprop(child, "pinmux"))
			continue;
		fdtbus_register_pinctrl_config(self, child,
		    &apple_pinctrl_funcs);

	}
}

CFATTACH_DECL_NEW(apple_pinctrl, sizeof(struct apple_pinctrl_softc),
    apple_pinctrl_match, apple_pinctrl_attach, NULL, NULL);