platform/x86: Add driver for ACPI INT0002 Virtual GPIO device (63dada87) · Commits · 戴 / test

drivers/platform/x86/Kconfig

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		@@ -794,6 +794,25 @@ config INTEL_CHT_INT33FE
		This driver instantiates i2c-clients for these, so that standard
		i2c drivers for these chips can bind to the them.

		config INTEL_INT0002_VGPIO
		tristate "Intel ACPI INT0002 Virtual GPIO driver"
		depends on GPIOLIB && ACPI
		select GPIOLIB_IRQCHIP
		---help---
		Some peripherals on Bay Trail and Cherry Trail platforms signal a
		Power Management Event (PME) to the Power Management Controller (PMC)
		to wakeup the system. When this happens software needs to explicitly
		clear the PME bus 0 status bit in the GPE0a_STS register to avoid an
		IRQ storm on IRQ 9.

		This is modelled in ACPI through the INT0002 ACPI device, which is
		called a "Virtual GPIO controller" in ACPI because it defines the
		event handler to call when the PME triggers through _AEI and _L02
		methods as would be done for a real GPIO interrupt in ACPI.

		To compile this driver as a module, choose M here: the module will
		be called intel_int0002_vgpio.

		config INTEL_HID_EVENT
		tristate "INTEL HID Event"
		depends on ACPI

drivers/platform/x86/Makefile

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		@@ -46,6 +46,7 @@ obj-$(CONFIG_TOSHIBA_BT_RFKILL) += toshiba_bluetooth.o
		obj-$(CONFIG_TOSHIBA_HAPS) += toshiba_haps.o
		obj-$(CONFIG_TOSHIBA_WMI) += toshiba-wmi.o
		obj-$(CONFIG_INTEL_CHT_INT33FE) += intel_cht_int33fe.o
		obj-$(CONFIG_INTEL_INT0002_VGPIO) += intel_int0002_vgpio.o
		obj-$(CONFIG_INTEL_HID_EVENT) += intel-hid.o
		obj-$(CONFIG_INTEL_VBTN) += intel-vbtn.o
		obj-$(CONFIG_INTEL_SCU_IPC) += intel_scu_ipc.o

drivers/platform/x86/intel_int0002_vgpio.c

0 → 100644

+219 −0

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		/*
		* Intel INT0002 "Virtual GPIO" driver
		*
		* Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
		*
		* Loosely based on android x86 kernel code which is:
		*
		* Copyright (c) 2014, Intel Corporation.
		*
		* Author: Dyut Kumar Sil <dyut.k.sil@intel.com>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License version 2 as
		* published by the Free Software Foundation.
		*
		* Some peripherals on Bay Trail and Cherry Trail platforms signal a Power
		* Management Event (PME) to the Power Management Controller (PMC) to wakeup
		* the system. When this happens software needs to clear the PME bus 0 status
		* bit in the GPE0a_STS register to avoid an IRQ storm on IRQ 9.
		*
		* This is modelled in ACPI through the INT0002 ACPI device, which is
		* called a "Virtual GPIO controller" in ACPI because it defines the event
		* handler to call when the PME triggers through _AEI and _L02 / _E02
		* methods as would be done for a real GPIO interrupt in ACPI. Note this
		* is a hack to define an AML event handler for the PME while using existing
		* ACPI mechanisms, this is not a real GPIO at all.
		*
		* This driver will bind to the INT0002 device, and register as a GPIO
		* controller, letting gpiolib-acpi.c call the _L02 handler as it would
		* for a real GPIO controller.
		*/

		#include <linux/acpi.h>
		#include <linux/bitmap.h>
		#include <linux/gpio/driver.h>
		#include <linux/interrupt.h>
		#include <linux/io.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/platform_device.h>
		#include <linux/slab.h>
		#include <linux/suspend.h>

		#include <asm/cpu_device_id.h>
		#include <asm/intel-family.h>

		#define DRV_NAME "INT0002 Virtual GPIO"

		/* For some reason the virtual GPIO pin tied to the GPE is numbered pin 2 */
		#define GPE0A_PME_B0_VIRT_GPIO_PIN 2

		#define GPE0A_PME_B0_STS_BIT BIT(13)
		#define GPE0A_PME_B0_EN_BIT BIT(13)
		#define GPE0A_STS_PORT 0x420
		#define GPE0A_EN_PORT 0x428

		#define ICPU(model) { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }

		static const struct x86_cpu_id int0002_cpu_ids[] = {
		/*
		* Limit ourselves to Cherry Trail for now, until testing shows we
		* need to handle the INT0002 device on Baytrail too.
		* ICPU(INTEL_FAM6_ATOM_SILVERMONT1), * Valleyview, Bay Trail *
		*/
		ICPU(INTEL_FAM6_ATOM_AIRMONT), /* Braswell, Cherry Trail */
		{}
		};

		/*
		* As this is not a real GPIO at all, but just a hack to model an event in
		* ACPI the get / set functions are dummy functions.
		*/

		static int int0002_gpio_get(struct gpio_chip *chip, unsigned int offset)
		{
		return 0;
		}

		static void int0002_gpio_set(struct gpio_chip *chip, unsigned int offset,
		int value)
		{
		}

		static int int0002_gpio_direction_output(struct gpio_chip *chip,
		unsigned int offset, int value)
		{
		return 0;
		}

		static void int0002_irq_ack(struct irq_data *data)
		{
		outl(GPE0A_PME_B0_STS_BIT, GPE0A_STS_PORT);
		}

		static void int0002_irq_unmask(struct irq_data *data)
		{
		u32 gpe_en_reg;

		gpe_en_reg = inl(GPE0A_EN_PORT);
		gpe_en_reg \|= GPE0A_PME_B0_EN_BIT;
		outl(gpe_en_reg, GPE0A_EN_PORT);
		}

		static void int0002_irq_mask(struct irq_data *data)
		{
		u32 gpe_en_reg;

		gpe_en_reg = inl(GPE0A_EN_PORT);
		gpe_en_reg &= ~GPE0A_PME_B0_EN_BIT;
		outl(gpe_en_reg, GPE0A_EN_PORT);
		}

		static irqreturn_t int0002_irq(int irq, void *data)
		{
		struct gpio_chip *chip = data;
		u32 gpe_sts_reg;

		gpe_sts_reg = inl(GPE0A_STS_PORT);
		if (!(gpe_sts_reg & GPE0A_PME_B0_STS_BIT))
		return IRQ_NONE;

		generic_handle_irq(irq_find_mapping(chip->irqdomain,
		GPE0A_PME_B0_VIRT_GPIO_PIN));

		pm_system_wakeup();

		return IRQ_HANDLED;
		}

		static struct irq_chip int0002_irqchip = {
		.name = DRV_NAME,
		.irq_ack = int0002_irq_ack,
		.irq_mask = int0002_irq_mask,
		.irq_unmask = int0002_irq_unmask,
		};

		static int int0002_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		const struct x86_cpu_id *cpu_id;
		struct gpio_chip *chip;
		int irq, ret;

		/* Menlow has a different INT0002 device? <sigh> */
		cpu_id = x86_match_cpu(int0002_cpu_ids);
		if (!cpu_id)
		return -ENODEV;

		irq = platform_get_irq(pdev, 0);
		if (irq < 0) {
		dev_err(dev, "Error getting IRQ: %d\n", irq);
		return irq;
		}

		chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
		if (!chip)
		return -ENOMEM;

		chip->label = DRV_NAME;
		chip->parent = dev;
		chip->owner = THIS_MODULE;
		chip->get = int0002_gpio_get;
		chip->set = int0002_gpio_set;
		chip->direction_input = int0002_gpio_get;
		chip->direction_output = int0002_gpio_direction_output;
		chip->base = -1;
		chip->ngpio = GPE0A_PME_B0_VIRT_GPIO_PIN + 1;
		chip->irq_need_valid_mask = true;

		ret = devm_gpiochip_add_data(&pdev->dev, chip, NULL);
		if (ret) {
		dev_err(dev, "Error adding gpio chip: %d\n", ret);
		return ret;
		}

		bitmap_clear(chip->irq_valid_mask, 0, GPE0A_PME_B0_VIRT_GPIO_PIN);

		/*
		* We manually request the irq here instead of passing a flow-handler
		* to gpiochip_set_chained_irqchip, because the irq is shared.
		*/
		ret = devm_request_irq(dev, irq, int0002_irq,
		IRQF_SHARED \| IRQF_NO_THREAD, "INT0002", chip);
		if (ret) {
		dev_err(dev, "Error requesting IRQ %d: %d\n", irq, ret);
		return ret;
		}

		ret = gpiochip_irqchip_add(chip, &int0002_irqchip, 0, handle_edge_irq,
		IRQ_TYPE_NONE);
		if (ret) {
		dev_err(dev, "Error adding irqchip: %d\n", ret);
		return ret;
		}

		gpiochip_set_chained_irqchip(chip, &int0002_irqchip, irq, NULL);

		return 0;
		}

		static const struct acpi_device_id int0002_acpi_ids[] = {
		{ "INT0002", 0 },
		{ },
		};
		MODULE_DEVICE_TABLE(acpi, int0002_acpi_ids);

		static struct platform_driver int0002_driver = {
		.driver = {
		.name = DRV_NAME,
		.acpi_match_table = int0002_acpi_ids,
		},
		.probe = int0002_probe,
		};

		module_platform_driver(int0002_driver);

		MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
		MODULE_DESCRIPTION("Intel INT0002 Virtual GPIO driver");
		MODULE_LICENSE("GPL");

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