diff options
| -rw-r--r-- | drivers/platform/x86/Kconfig | 19 | ||||
| -rw-r--r-- | drivers/platform/x86/Makefile | 1 | ||||
| -rw-r--r-- | drivers/platform/x86/intel_int0002_vgpio.c | 219 |
3 files changed, 239 insertions, 0 deletions
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index 8489020ecf44..a3ccc3c795a5 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -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 diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 182a3ed6605a..ab22ce77fb66 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -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 diff --git a/drivers/platform/x86/intel_int0002_vgpio.c b/drivers/platform/x86/intel_int0002_vgpio.c new file mode 100644 index 000000000000..92dc230ef5b2 --- /dev/null +++ b/drivers/platform/x86/intel_int0002_vgpio.c @@ -0,0 +1,219 @@ +/* + * 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"); |