+Cc: Mika (that's why left all content + one my comment below)
On Fri, Apr 21, 2017 at 3:52 PM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> Some peripherals on Baytrail and Cherrytrail platforms signal PME to the
> PMC to wakeup the system. When this happens software needs to clear the
> PME_B0_STS bit in the GPE0a_STS register to avoid an IRQ storm on IRQ 9.
>
> This is modelled in ACPI through the INT0002 ACPI device.
>
> This commit adds a driver which will bind to that device, call the
> ACPI event handler for the wakeup and clear the interrupt source
> avoiding the irq storm.
>
> Cc: joeyli <jlee@xxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> Tested-by: Takashi Iwai <tiwai@xxxxxxx>
> ---
> Changes in v2:
> -Remove dev_err after malloc failure
> -Remove unused empty runtime pm callbacks
> -s/GPE0A_PME_/GPE0A_PME_B0_/
> -Fixed some checkpatch warnings (I forgot to run checkpatch on v1)
> ---
> drivers/platform/x86/Kconfig | 10 ++
> drivers/platform/x86/Makefile | 1 +
> drivers/platform/x86/intel_int0002.c | 214 +++++++++++++++++++++++++++++++++++
> 3 files changed, 225 insertions(+)
> create mode 100644 drivers/platform/x86/intel_int0002.c
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 53afa78..be2ffbd 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -889,6 +889,16 @@ config INTEL_PMC_CORE
> Supported features:
> - SLP_S0_RESIDENCY counter.
>
> +config INTEL_INT0002
> + tristate "Intel INT0002 Virtual GPIO ACPI device driver"
> + depends on X86 && ACPI
> + ---help---
> + Some peripherals on Baytrail and Cherrytrail platforms signal
> + PME to the PMC to wakeup the system. When this happens software
> + needs to explicitly clear the interrupt source to avoid an IRQ
> + storm on IRQ 9. This is modelled in ACPI through the INT0002
> + ACPI device. This driver implements the clearing of the IRQ.
> +
> config IBM_RTL
> tristate "Device driver to enable PRTL support"
> depends on PCI
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 6731893..de4ffb5 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -51,6 +51,7 @@ obj-$(CONFIG_INTEL_SCU_IPC) += intel_scu_ipc.o
> obj-$(CONFIG_INTEL_SCU_IPC_UTIL) += intel_scu_ipcutil.o
> obj-$(CONFIG_INTEL_MFLD_THERMAL) += intel_mid_thermal.o
> obj-$(CONFIG_INTEL_IPS) += intel_ips.o
> +obj-$(CONFIG_INTEL_INT0002) += intel_int0002.o
> obj-$(CONFIG_XO1_RFKILL) += xo1-rfkill.o
> obj-$(CONFIG_XO15_EBOOK) += xo15-ebook.o
> obj-$(CONFIG_IBM_RTL) += ibm_rtl.o
> diff --git a/drivers/platform/x86/intel_int0002.c b/drivers/platform/x86/intel_int0002.c
> new file mode 100644
> index 0000000..52aab58
> --- /dev/null
> +++ b/drivers/platform/x86/intel_int0002.c
> @@ -0,0 +1,214 @@
> +/*
> + * Intel INT0002 "Virtual GPIO" driver
> + *
> + * Copyright (C) 2017 Hans de Goede <hdegoede@xxxxxxxxxx>
> + *
> + * Loosely based on android x86 kernel code which is:
> + *
> + * Copyright (c) 2014, Intel Corporation.
> + *
> + * Author: Dyut Kumar Sil <dyut.k.sil@xxxxxxxxx>
> + *
> + * 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 Baytrail and Cherrytrail platforms signal PME to the
> + * PMC to wakeup the system. When this happens software needs to clear the
> + * PME_B0_STS 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.
> + *
> + * This driver will bind to the INT0002 device, call the ACPI event handler
> + * for the wakeup and clear the interrupt source avoiding the irq storm.
> + */
> +
> +#include <asm/cpu_device_id.h>
> +#include <asm/intel-family.h>
> +#include <linux/acpi.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/slab.h>
> +
> +#define GPE0A_PME_B0_STS_BIT 0x2000
> +#define GPE0A_PME_B0_EN_BIT 0x2000
> +#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 */
> + {}
> +};
> +
> +struct int0002_data {
> + spinlock_t lock;
> + struct device *dev;
> + const struct x86_cpu_id *cpu_id;
> + acpi_handle handle;
> + char ev_name[5];
> +};
> +
> +static void int0002_irq_enable(struct int0002_data *data, bool enable)
> +{
> + unsigned long flags;
> + u32 gpe_en_reg;
> +
> + spin_lock_irqsave(&data->lock, flags);
> +
> + gpe_en_reg = inl(GPE0A_EN_PORT);
> + if (enable)
> + gpe_en_reg |= GPE0A_PME_B0_EN_BIT;
> + else
> + gpe_en_reg &= ~GPE0A_PME_B0_EN_BIT;
> + outl(gpe_en_reg, GPE0A_EN_PORT);
> +
> + spin_unlock_irqrestore(&data->lock, flags);
> +}
> +
> +static irqreturn_t int0002_irq_handler(int irq, void *handler_data)
> +{
> + struct int0002_data *data = handler_data;
> + u32 gpe_sts_reg;
> +
> + gpe_sts_reg = inl(GPE0A_STS_PORT);
> + if (!(gpe_sts_reg & GPE0A_PME_B0_STS_BIT))
> + return IRQ_NONE;
> +
> + int0002_irq_enable(data, false);
> +
> + return IRQ_WAKE_THREAD;
> +}
> +
> +static irqreturn_t int0002_irq_thread(int irq, void *handler_data)
> +{
> + struct int0002_data *data = handler_data;
> + acpi_status status;
> +
> + /* Don't call ACPI event handler on Baytrail? Taken from Android-x86 */
> + if (data->cpu_id->model != INTEL_FAM6_ATOM_SILVERMONT1) {
> + status = acpi_evaluate_object(data->handle, data->ev_name,
> + NULL, NULL);
> + if (ACPI_FAILURE(status))
> + dev_err(data->dev, "Error calling %s\n", data->ev_name);
> + }
> +
> + /* Ack and then re-enable IRQ */
> + outl(GPE0A_PME_B0_STS_BIT, GPE0A_STS_PORT);
> + int0002_irq_enable(data, true);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int int0002_probe(struct platform_device *pdev)
> +{
> + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER, NULL };
> + struct device *dev = &pdev->dev;
> + struct int0002_data *data;
> + struct acpi_resource *res;
> + acpi_status status;
> + acpi_handle hdl;
> + int irq, ret;
> +
> + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + spin_lock_init(&data->lock);
> + data->dev = dev;
> +
> + /* Menlow has a different INT0002 device? <sigh> */
> + data->cpu_id = x86_match_cpu(int0002_cpu_ids);
> + if (!data->cpu_id)
> + return -ENODEV;
> +
> + data->handle = ACPI_HANDLE(dev);
> + if (!data->handle)
> + return -ENODEV;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(dev, "Error getting IRQ: %d\n", irq);
> + return irq;
> + }
> +
> + status = acpi_get_event_resources(data->handle, &buf);
> + if (ACPI_FAILURE(status)) {
> + dev_err(dev, "Error getting acpi event resources\n");
> + return -ENODEV;
> + }
> +
> + /* Find the "GPIO interrupt" event handler to call upon PME */
> + ret = -ENODEV;
> + for (res = buf.pointer;
> + res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
> + res = ACPI_NEXT_RESOURCE(res)) {
> +
> + if (res->type != ACPI_RESOURCE_TYPE_GPIO ||
> + res->data.gpio.connection_type !=
> + ACPI_RESOURCE_GPIO_TYPE_INT)
> + continue;
> +
> + snprintf(data->ev_name, sizeof(data->ev_name), "_%c%02X",
> + res->data.gpio.triggering ? 'E' : 'L',
> + res->data.gpio.pin_table[0]);
> +
> + status = acpi_get_handle(data->handle, data->ev_name, &hdl);
> + if (ACPI_SUCCESS(status)) {
> + ret = 0;
> + break;
> + }
I still think it might make sense to split it to some generic helper
(same code is used in gpiolib-acpi.c).
> + }
> +
> + ACPI_FREE(buf.pointer);
> +
> + if (ret) {
> + dev_err(dev, "Error could not find event handler\n");
> + return ret;
> + }
> +
> + ret = devm_request_threaded_irq(dev, irq,
> + int0002_irq_handler, int0002_irq_thread,
> + IRQF_SHARED, "INT0002", data);
> + if (ret) {
> + dev_err(dev, "Error requesting IRQ %d: %d\n", irq, ret);
> + return ret;
> + }
> +
> + int0002_irq_enable(data, true);
> +
> + 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 = "Intel INT0002 Virtual GPIO",
> + .acpi_match_table = ACPI_PTR(int0002_acpi_ids),
> + },
> + .probe = int0002_probe,
> +};
> +
> +module_platform_driver(int0002_driver);
> +
> +MODULE_AUTHOR("Hans de Goede <hdegoede@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Intel INT0002 Virtual GPIO driver");
> +MODULE_LICENSE("GPL");
> --
> 2.9.3
>
--
With Best Regards,
Andy Shevchenko
