[PATCH v2] platform/x86: Add driver for INT0002 ACPI device

[PATCH v2] platform/x86: Add driver for INT0002 ACPI device

[Hans de Goede]

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@suse.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
---
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@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 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;
+		}
+	}
+
+	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@redhat.com>");
+MODULE_DESCRIPTION("Intel INT0002 Virtual GPIO driver");
+MODULE_LICENSE("GPL");
-- 
2.9.3

Re: [PATCH v2] platform/x86: Add driver for INT0002 ACPI device

[joeyli]

Hi,

On Fri, Apr 21, 2017 at 02:52:46PM +0200, Hans de Goede 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@suse.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> Tested-by: Takashi Iwai <tiwai@suse.de>
> ---
> 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)

Please feel free to add:
	Reviewed-by: Joey Lee <jlee@suse.com>

Thanks a lot!
Joey Lee

Re: [PATCH v2] platform/x86: Add driver for INT0002 ACPI device

[Andy Shevchenko]

+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@redhat.com> 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@suse.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> Tested-by: Takashi Iwai <tiwai@suse.de>
> ---
> 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@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 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@redhat.com>");
> +MODULE_DESCRIPTION("Intel INT0002 Virtual GPIO driver");
> +MODULE_LICENSE("GPL");
> --
> 2.9.3
>



-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] platform/x86: Add driver for INT0002 ACPI device

[Mika Westerberg]

On Mon, Apr 24, 2017 at 12:40:30PM +0300, Andy Shevchenko wrote:
> +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@redhat.com> 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@suse.com>
> > Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> > Tested-by: Takashi Iwai <tiwai@suse.de>
> > ---
> > 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@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 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).

I agree and further if this device has _AEI I would investigate how you
could get acpi_gpiochip_request_interrupts() to cope with it.

Re: [PATCH v2] platform/x86: Add driver for INT0002 ACPI device

[Hans de Goede]

Hi,

On 04/24/2017 12:42 PM, Mika Westerberg wrote:
> On Mon, Apr 24, 2017 at 12:40:30PM +0300, Andy Shevchenko wrote:
>> +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@redhat.com> 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@suse.com>
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>> Tested-by: Takashi Iwai <tiwai@suse.de>
>>> ---
>>> 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@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 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).
> 
> I agree and further if this device has _AEI I would investigate how you
> could get acpi_gpiochip_request_interrupts() to cope with it.

Thank you for the review / the remarks.

I'm about to post a new version as a result of these remarks I've converted
the driver into a (virtual) gpiochip driver to match how things are modelled
in the DSDT, this removes the need for any direct interaction with the ACPI
subsys, letting gpiolib-acpi take care of everything.

Regards,

Hans