/* Copyright 2014 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "common.h"
#include "console.h"
#include "gpio.h"
#include "hooks.h"
#include "registers.h"
#include "task.h"

/*
 * The Cr50's ARM core has two GPIO ports of 16 bits each. Each GPIO signal
 * can be routed through a full NxM crossbar to any of a number of external
 * pins. When setting up GPIOs, both the ARM core and the crossbar must be
 * configured correctly. This file is only concerned with the ARM core.
 */

test_mockable int gpio_get_level(enum gpio_signal signal)
{
	const struct gpio_info *g = gpio_list + signal;
	return !!(GR_GPIO_DATAIN(g->port) & g->mask);
}

static void set_one_gpio_bit(uint32_t port, uint16_t mask, int value)
{
	if (!mask)
		return;

	/* Assumes mask has one and only one bit set */
	if (mask & 0x00FF)
		GR_GPIO_MASKLOWBYTE(port, mask) = value ? mask : 0;
	else
		GR_GPIO_MASKHIGHBYTE(port, mask >> 8) = value ? mask : 0;
}

void gpio_set_level(enum gpio_signal signal, int value)
{
	const struct gpio_info *g = gpio_list + signal;

	if (g->flags & GPIO_OPEN_DRAIN) {
		if (value) {
			GR_GPIO_CLRDOUTEN(g->port) = g->mask;
			/* Don't ever set ODR output to HIGH. */
			return;
		}
		GR_GPIO_SETDOUTEN(g->port) = g->mask;
	}

	set_one_gpio_bit(g->port, g->mask, value);
}

int gpio_get_flags_by_mask(uint32_t port, uint32_t mask)
{
	uint32_t flags = 0;
	uint32_t val = 0;

	/* Only one bit must be set. */
	if ((mask != (mask & -mask)) || (mask == 0))
		return 0;

	/* Check mode. */
	/* ARM DDI 0479B: 3.5.2 */
	val = GR_GPIO_SETDOUTEN(port) & mask;
	if (val) {
		flags |= GPIO_OUTPUT;
		val = GR_GPIO_DOUT(port) & mask;
		if (val)
			flags |= GPIO_HIGH;
		else
			flags |= GPIO_LOW;
	} else
		flags |= GPIO_INPUT;

	return flags;
}

void gpio_set_flags_by_mask(uint32_t port, uint32_t mask, uint32_t flags)
{
	/* Output must be enabled when needed, input is always enabled */
	if (flags & GPIO_OUTPUT) {

		if (flags & GPIO_LOW)
			set_one_gpio_bit(port, mask, 0);
		else if ((flags & GPIO_HIGH) && !(flags & GPIO_OPEN_DRAIN))
			/* Set to HIGH only if not open drain. */
			set_one_gpio_bit(port, mask, 1);

		if (!(flags & GPIO_OPEN_DRAIN) || (flags & GPIO_LOW))
			/*
			 * Enable output for push-pull (high or low), or
			 * open-drain low.
			 */
			GR_GPIO_SETDOUTEN(port) = mask;
		else if (flags & GPIO_OPEN_DRAIN)
			/*
			 * Disable output for other open-drain cases to get a
			 * high-Z pin.
			 */
			GR_GPIO_CLRDOUTEN(port) = mask;
	} else {
		GR_GPIO_CLRDOUTEN(port) = mask;
	}

	/* Interrupt types */
	if (flags & GPIO_INT_F_LOW) {
		GR_GPIO_CLRINTTYPE(port) = mask;
		GR_GPIO_CLRINTPOL(port) = mask;
	}
	if (flags & GPIO_INT_F_HIGH) {
		GR_GPIO_CLRINTTYPE(port) = mask;
		GR_GPIO_SETINTPOL(port) = mask;
	}
	if (flags & GPIO_INT_F_FALLING) {
		GR_GPIO_SETINTTYPE(port) = mask;
		GR_GPIO_CLRINTPOL(port) = mask;
	}
	if (flags & GPIO_INT_F_RISING) {
		GR_GPIO_SETINTTYPE(port) = mask;
		GR_GPIO_SETINTPOL(port) = mask;
	}
	/* No way to trigger on both rising and falling edges, darn it. */
}

void gpio_set_alternate_function(uint32_t port, uint32_t mask, int func)
{
	/* This HW feature is not present in the Cr50 ARM core */
}

/*
 * A pinmux_config contains the selector offset and selector value for a
 * particular pinmux entry.
 */
struct pinmux_config {
	uint16_t offset;
	uint16_t value;
};

#define PINMUX_CONFIG(name) {						\
		.offset = CONCAT3(GC_PINMUX_, name, _SEL_OFFSET),	\
		.value  = CONCAT3(GC_PINMUX_, name, _SEL),		\
	}

/*
 * The pinmux struct contains a full description of the connection of a DIO to
 * a GPIO, an internal peripheral, or as a direct input.  The flag
 * DIO_TO_PERIPHERAL is used to select between the two union entries.  There
 * is no union entry for direct input because it requires no parameters.
 */
struct pinmux {
	union {
		enum gpio_signal     signal;
		struct pinmux_config peripheral;
	};
	struct pinmux_config dio;
	uint16_t             flags;
};

/*
 * These macros are used to add flags indicating the type of mapping requested.
 * DIO_TO_PERIPHERAL for FUNC mappings.
 * DIO_ENABLE_DIRECT_INPUT for DIRECT mappings.
 */
#define FLAGS_FUNC(name) DIO_TO_PERIPHERAL
#define FLAGS_GPIO(name) 0
#define FLAGS_DIRECT     DIO_ENABLE_DIRECT_INPUT

/*
 * These macros are used to selectively initialize the anonymous union based
 * on the type of pinmux mapping requested (FUNC, GPIO, or DIRECT).
 */
#define PINMUX_FUNC(name) .peripheral = PINMUX_CONFIG(name),
#define PINMUX_GPIO(name) .signal     = CONCAT2(GPIO_, name),
#define PINMUX_DIRECT

/*
 * Initialize an entry for the pinmux list.  The first parameter can be either
 * FUNC(name) or GPIO(name) depending on the type of mapping required.  The
 * second argument is the DIO name to map to.  And the final argument is the
 * flags set for this mapping, this macro adds the DIO_TO_PERIPHERAL flag for
 * a FUNC mapping.
 */
#define PINMUX(name, dio_name, dio_flags) {		\
		PINMUX_##name				\
		.dio   = PINMUX_CONFIG(DIO##dio_name),	\
		.flags = dio_flags | FLAGS_##name	\
	},

static const struct pinmux pinmux_list[] = {
	#include "gpio.wrap"
};

/* Return true if DIO should be a digital input */
static int connect_dio_to_peripheral(struct pinmux const *p)
{
	if (p->flags & DIO_OUTPUT)
		DIO_SEL_REG(p->dio.offset) = p->peripheral.value;

	if (p->flags & DIO_INPUT)
		DIO_SEL_REG(p->peripheral.offset) = p->dio.value;

	return p->flags & DIO_INPUT;
}

/* Return true if DIO should be a digital input */
static int connect_dio_to_gpio(struct pinmux const *p)
{
	const struct gpio_info *g = gpio_list + p->signal;
	int bitnum = GPIO_MASK_TO_NUM(g->mask);

	if ((g->flags & GPIO_OUTPUT) || (p->flags & DIO_OUTPUT))
		DIO_SEL_REG(p->dio.offset) = GET_GPIO_FUNC(g->port, bitnum);

	if ((g->flags & GPIO_INPUT) || (p->flags & DIO_INPUT))
		GET_GPIO_SEL_REG(g->port, bitnum) = p->dio.value;

	if (g->flags & GPIO_PULL_UP)
		REG_WRITE_MLV(DIO_CTL_REG(p->dio.offset),
			      DIO_CTL_PU_MASK,
			      DIO_CTL_PU_LSB, 1);

	if (g->flags & GPIO_PULL_DOWN)
		REG_WRITE_MLV(DIO_CTL_REG(p->dio.offset),
			      DIO_CTL_PD_MASK,
			      DIO_CTL_PD_LSB, 1);

	return (g->flags & GPIO_INPUT) || (p->flags & DIO_INPUT);
}

static void connect_pinmux(struct pinmux const *p)
{
	uint32_t bitmask;
	int is_input;

	if (p->flags & DIO_ENABLE_DIRECT_INPUT) {
		/* We don't have to setup any muxes for directly connected
		 * pads. The only ones that we are likely to ever care about
		 * are tied to the SPS and SPI peripherals, and they're all
		 * inouts, so we can just enable the digital input for them
		 * regardless. */
		is_input = 1;
	} else {
		/* Pads that must be muxed to specific GPIOs or peripherals may
		 * or may not be inputs. We'll check those individually. */
		if (p->flags & DIO_TO_PERIPHERAL)
			is_input = connect_dio_to_peripheral(p);
		else
			is_input = connect_dio_to_gpio(p);
	}

	/* Configure the DIO pad controls */
	if (is_input)
		REG_WRITE_MLV(DIO_CTL_REG(p->dio.offset),
			      DIO_CTL_IE_MASK,
			      DIO_CTL_IE_LSB, 1);
	if (p->flags & DIO_PULL_UP)
		REG_WRITE_MLV(DIO_CTL_REG(p->dio.offset),
			      DIO_CTL_PU_MASK,
			      DIO_CTL_PU_LSB, 1);
	if (p->flags & DIO_PULL_DOWN)
		REG_WRITE_MLV(DIO_CTL_REG(p->dio.offset),
			      DIO_CTL_PD_MASK,
			      DIO_CTL_PD_LSB, 1);

	/* Enable any wake pins needed to exit low-power modes */
	if ((p->flags & DIO_WAKE_EN0) &&
	    (p->dio.offset <= GC_PINMUX_DIOB7_SEL_OFFSET)) { /* not VIOn ! */
		bitmask = (1 << (p->dio.offset / 8));

		/* enable pad as wake source */
		GREG32(PINMUX, EXITEN0) |= bitmask;

		/* level (0) or edge sensitive (1) */
		if (p->flags & DIO_WAKE_EDGE0)
			GREG32(PINMUX, EXITEDGE0) |= bitmask;
		else
			GREG32(PINMUX, EXITEDGE0) &= ~bitmask;

		/* high/rising (0) or low/falling (1) */
		if (p->flags & DIO_WAKE_INV0)
			GREG32(PINMUX, EXITINV0) |= bitmask;
		else
			GREG32(PINMUX, EXITINV0) &= ~bitmask;
	}
}

int gpio_enable_interrupt(enum gpio_signal signal)
{
	const struct gpio_info *g = gpio_list + signal;
	GR_GPIO_SETINTEN(g->port) = g->mask;
	return EC_SUCCESS;
}

int gpio_disable_interrupt(enum gpio_signal signal)
{
	const struct gpio_info *g = gpio_list + signal;
	GR_GPIO_CLRINTEN(g->port) = g->mask;
	return EC_SUCCESS;
}

int gpio_clear_pending_interrupt(enum gpio_signal signal)
{
	const struct gpio_info *g = gpio_list + signal;
	GR_GPIO_CLRINTSTAT(g->port) = g->mask;
	return EC_SUCCESS;
}

void gpio_pre_init(void)
{
	const struct gpio_info *g = gpio_list;

	int i;

	/* Enable clocks */
	REG_WRITE_MLV(GR_PMU_PERICLKSET0,
		      GC_PMU_PERICLKSET0_DGPIO0_CLK_MASK,
		      GC_PMU_PERICLKSET0_DGPIO0_CLK_LSB, 1);
	REG_WRITE_MLV(GR_PMU_PERICLKSET0,
		      GC_PMU_PERICLKSET0_DGPIO1_CLK_MASK,
		      GC_PMU_PERICLKSET0_DGPIO1_CLK_LSB, 1);

	/* Set up the pinmux */
	for (i = 0; i < ARRAY_SIZE(pinmux_list); i++)
		connect_pinmux(pinmux_list + i);

	/* Set up ARM core GPIOs */
	for (i = 0; i < GPIO_COUNT; i++, g++)
		if (g->mask && !(g->flags & GPIO_DEFAULT))
			gpio_set_flags_by_mask(g->port, g->mask, g->flags);
}

static void gpio_init(void)
{
	task_enable_irq(GC_IRQNUM_GPIO0_GPIOCOMBINT);
	task_enable_irq(GC_IRQNUM_GPIO1_GPIOCOMBINT);
}
DECLARE_HOOK(HOOK_INIT, gpio_init, HOOK_PRIO_DEFAULT);

/*****************************************************************************/
/* Interrupt handler stuff */

static void gpio_invoke_handler(uint32_t port, uint32_t mask)
{
	const struct gpio_info *g = gpio_list;
	int i;
	for (i = 0; i < GPIO_IH_COUNT; i++, g++)
		if (port == g->port && (mask & g->mask))
			gpio_irq_handlers[i](i);
}

static void gpio_interrupt(int port)
{
	int bitnum;
	uint32_t mask;
	uint32_t pending = GR_GPIO_CLRINTSTAT(port);

	while (pending) {
		bitnum = GPIO_MASK_TO_NUM(pending);
		mask = 1 << bitnum;
		pending &= ~mask;
		gpio_invoke_handler(port, mask);
		GR_GPIO_CLRINTSTAT(port) = mask;
	}
}

void _gpio0_interrupt(void)
{
	gpio_interrupt(0);
}
void _gpio1_interrupt(void)
{
	gpio_interrupt(1);
}
DECLARE_IRQ(GC_IRQNUM_GPIO0_GPIOCOMBINT, _gpio0_interrupt, 1);
DECLARE_IRQ(GC_IRQNUM_GPIO1_GPIOCOMBINT, _gpio1_interrupt, 1);

/*
 * The uart, i2c, and spi suffix arrays must match the order of the pinmux
 * select registers in chip/g/hw_regdefs.h. If the order is incorrect, the
 * pinmux command output will be wrong.
 */
static const char * const uart_str[] = {
	"0_CTS", "0_RTS", "0_RX", "0_TX",
	"1_CTS", "1_RTS", "1_RX", "1_TX",
	"2_CTS", "2_RTS", "2_RX", "2_TX",
};

static const char * const i2c_str[] = {
	"0_SCL", "0_SDA",
	"1_SCL", "1_SDA",
	"S0_SCL", "S0_SDA",
};

static const char * const spi_str[] = {
	"SPICLK", "SPICSB", "SPIMISO", "SPIMOSI",
};

static void print_periph(int sel)
{
	if (sel >= 1 && sel <= 16)
		ccprintf("GPIO0_GPIO%d", sel - 1);
	else if (sel >= 17 && sel <= 32)
		ccprintf("GPIO1_GPIO%d", sel - 17);
	else if (sel >= 33 && sel <= 38)
		ccprintf("I2C%s", i2c_str[sel - 33]);
	else if (sel >= 49 && sel <= 52)
		ccprintf("SPI1_%s", spi_str[sel - 49]);
	else if (sel >= 67 && sel <= 78)
		ccprintf("UART%s", uart_str[sel - 67]);
	else if (sel)
		ccprintf("UNDEF");
}

static void show_pinmux(const char name, int i, int ofs)
{
	uint32_t sel = DIO_SEL_REG(i * 8 + ofs);
	uint32_t ctl = DIO_CTL_REG(i * 8 + ofs);
	uint32_t bitmask = 1 << (i + ofs / 8);
	uint32_t edge = GREG32(PINMUX, EXITEDGE0) & bitmask;

	/* skip empty ones (ignoring drive strength bits) */
	if (!sel && !(ctl & (0xf << 2)) && !(GREG32(PINMUX, EXITEN0) & bitmask))
		return;

	ccprintf("%08x: DIO%c%-2d  %2d %3s%3s%3s%4s ",
		 GC_PINMUX_BASE_ADDR + i * 8 + ofs,
		 name, i, sel,
		 (ctl & BIT(2)) ? " IN" : "",
		 (ctl & BIT(3)) ? " PD" : "",
		 (ctl & BIT(4)) ? " PU" : "",
		 (ctl & BIT(5)) ? " INV" : "");

	print_periph(sel);

	if (GREG32(PINMUX, EXITEN0) & bitmask) {
		ccprintf("  WAKE_");
		if (GREG32(PINMUX, EXITINV0) & bitmask)
			ccprintf("%s", edge ? "FALLING" : "LOW");
		else
			ccprintf("%s", edge ? "RISING" : "HIGH");
	}
	ccprintf("\n");
	cflush();
}

static void print_dio_str(uint32_t sel)
{
	if (sel >= 1 && sel <= 2)
		ccprintf("  VIO%d\n", 2 - sel);
	else if (sel >= 3 && sel <= 10)
		ccprintf("  DIOB%d\n", 10 - sel);
	else if (sel >= 11 && sel <= 25)
		ccprintf("  DIOA%d\n", 25 - sel);
	else if (sel >= 26 && sel <= 30)
		ccprintf("  DIOM%d\n", 30 - sel);
	else
		ccprintf("\n");
	cflush();
}

static void show_pinmux_periph(int i)
{
	uint32_t ofs = GC_PINMUX_GPIO0_GPIO0_SEL_OFFSET + i * 4;
	uint32_t sel = DIO_SEL_REG(ofs);

	if (sel == 0)
		return;

	ccprintf("%08x: ", GC_PINMUX_BASE_ADDR + ofs);
	print_periph(i + 1);

	ccprintf("\t%2d", sel);
	print_dio_str(sel);
}

static int command_pinmux(int argc, char **argv)
{
	size_t i;

	const struct {
		char name;
		uint8_t count;
		uint8_t base_offset;
	} pads[] = {
		{'M',  5,    0},
		{'A', 15, 0x28},
		{'B',  8, 0xa0},
		{'V',  2, 0xe8},
	};

	for (i = 0; i < ARRAY_SIZE(pads); i++) {
		uint8_t j;

		for (j = 0; j < pads[i].count; j++)
			show_pinmux(pads[i].name, j, pads[i].base_offset);
	}

	ccprintf("\n");

	/* GPIO & Peripheral sources */
	for (i = 0; i <= 98; i++)
		show_pinmux_periph(i);

	ccprintf("\n");
	return EC_SUCCESS;
}
DECLARE_SAFE_CONSOLE_COMMAND(pinmux, command_pinmux,
			     "",
			     "Display pinmux info");

static const char * const int_str[] = {
	"LOW", "FALLING", "HIGH", "RISING",
};

static void show_gpiocfg(int n)
{
	uint32_t din = GR_GPIO_DATAIN(n);
	uint32_t dout = GR_GPIO_DOUT(n);
	uint32_t outen = GR_GPIO_SETDOUTEN(n);
	uint32_t inten = GR_GPIO_SETINTEN(n);
	uint32_t intpol = GR_GPIO_SETINTPOL(n);
	uint32_t inttype = GR_GPIO_SETINTTYPE(n);
	uint32_t mask;
	int i, j;

	for (i = 0, mask = 0x1; i < 16; i++, mask <<= 1) {
		/* Skip it unless it's an output or an interrupt */
		if (!((outen & mask) || (inten & mask)))
			continue;

		ccprintf("GPIO%d_GPIO%d:\tread %d", n, i, !!(din & mask));
		if (outen & mask)
			ccprintf(" drive %d", !!(dout & mask));
		if (inten & mask) {
			j = ((intpol & mask) ? 2 : 0) +
				((inttype & mask) ? 1 : 0);
			ccprintf(" INT_%s", int_str[j]);
		}
		ccprintf("\n");
	}
}

static int command_gpiocfg(int argc, char **argv)
{
	show_gpiocfg(0);
	show_gpiocfg(1);

	return EC_SUCCESS;
}
DECLARE_SAFE_CONSOLE_COMMAND(gpiocfg, command_gpiocfg,
			     "",
			     "Display GPIO configs");