path: root/drivers/platform/x86/x86-android-tablets.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * DMI based code to deal with broken DSDTs on X86 tablets which ship with
 * Android as (part of) the factory image. The factory kernels shipped on these
 * devices typically have a bunch of things hardcoded, rather than specified
 * in their DSDT.
 *
 * Copyright (C) 2021 Hans de Goede <hdegoede@redhat.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/gpio_keys.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/power/bq24190_charger.h>
#include <linux/serdev.h>
#include <linux/string.h>
/* For gpio_get_desc() which is EXPORT_SYMBOL_GPL() */
#include "../../gpio/gpiolib.h"
#include "../../gpio/gpiolib-acpi.h"

/*
 * Helper code to get Linux IRQ numbers given a description of the IRQ source
 * (either IOAPIC index, or GPIO chip name + pin-number).
 */
enum x86_acpi_irq_type {
	X86_ACPI_IRQ_TYPE_NONE,
	X86_ACPI_IRQ_TYPE_APIC,
	X86_ACPI_IRQ_TYPE_GPIOINT,
	X86_ACPI_IRQ_TYPE_PMIC,
};

struct x86_acpi_irq_data {
	char *chip;   /* GPIO chip label (GPIOINT) or PMIC ACPI path (PMIC) */
	enum x86_acpi_irq_type type;
	enum irq_domain_bus_token domain;
	int index;
	int trigger;  /* ACPI_EDGE_SENSITIVE / ACPI_LEVEL_SENSITIVE */
	int polarity; /* ACPI_ACTIVE_HIGH / ACPI_ACTIVE_LOW / ACPI_ACTIVE_BOTH */
};

static int gpiochip_find_match_label(struct gpio_chip *gc, void *data)
{
	return gc->label && !strcmp(gc->label, data);
}

static int x86_android_tablet_get_gpiod(char *label, int pin, struct gpio_desc **desc)
{
	struct gpio_desc *gpiod;
	struct gpio_chip *chip;

	chip = gpiochip_find(label, gpiochip_find_match_label);
	if (!chip) {
		pr_err("error cannot find GPIO chip %s\n", label);
		return -ENODEV;
	}

	gpiod = gpiochip_get_desc(chip, pin);
	if (IS_ERR(gpiod)) {
		pr_err("error %ld getting GPIO %s %d\n", PTR_ERR(gpiod), label, pin);
		return PTR_ERR(gpiod);
	}

	*desc = gpiod;
	return 0;
}

static int x86_acpi_irq_helper_get(const struct x86_acpi_irq_data *data)
{
	struct irq_fwspec fwspec = { };
	struct irq_domain *domain;
	struct acpi_device *adev;
	struct gpio_desc *gpiod;
	unsigned int irq_type;
	acpi_handle handle;
	acpi_status status;
	int irq, ret;

	switch (data->type) {
	case X86_ACPI_IRQ_TYPE_APIC:
		/*
		 * The DSDT may already reference the GSI in a device skipped by
		 * acpi_quirk_skip_i2c_client_enumeration(). Unregister the GSI
		 * to avoid EBUSY errors in this case.
		 */
		acpi_unregister_gsi(data->index);
		irq = acpi_register_gsi(NULL, data->index, data->trigger, data->polarity);
		if (irq < 0)
			pr_err("error %d getting APIC IRQ %d\n", irq, data->index);

		return irq;
	case X86_ACPI_IRQ_TYPE_GPIOINT:
		/* Like acpi_dev_gpio_irq_get(), but without parsing ACPI resources */
		ret = x86_android_tablet_get_gpiod(data->chip, data->index, &gpiod);
		if (ret)
			return ret;

		irq = gpiod_to_irq(gpiod);
		if (irq < 0) {
			pr_err("error %d getting IRQ %s %d\n", irq, data->chip, data->index);
			return irq;
		}

		irq_type = acpi_dev_get_irq_type(data->trigger, data->polarity);
		if (irq_type != IRQ_TYPE_NONE && irq_type != irq_get_trigger_type(irq))
			irq_set_irq_type(