Commit 4738d8aa authored by Pali Rohár's avatar Pali Rohár Committed by Matthew Garrett
Browse files

platform: x86: dell-smo8800: Dell Latitude freefall driver (ACPI SMO8800/SMO8810) 



This acpi driver provide supports for freefall sensors SMO8800/SMO8810 which
can be found on Dell Latitude laptops. Driver register /dev/freefall misc
device which has same interface as driver hp_accel freefall driver. So any
existing applications for HP freefall sensor /dev/freefall will work for with
this new driver for Dell Latitude laptops too.

Signed-off-by: default avatarPali Rohár <pali.rohar@gmail.com>
Cc: Sonal Santan <sonal.santan@gmail.com>
Tested-By: default avatarValdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-By: default avatarValdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: default avatarMatthew Garrett <matthew.garrett@nebula.com>
parent b3facd7b

drivers/platform/x86/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -127,6 +127,16 @@ config DELL_WMI_AIO 
	  To compile this driver as a module, choose M here: the module will

	  be called dell-wmi-aio.



config DELL_SMO8800

	tristate "Dell Latitude freefall driver (ACPI SMO8800/SMO8810)"

	depends on ACPI

	---help---

	  Say Y here if you want to support SMO8800/SMO8810 freefall device

	  on Dell Latitude laptops.



	  To compile this driver as a module, choose M here: the module will

	  be called dell-smo8800.





config FUJITSU_LAPTOP

	tristate "Fujitsu Laptop Extras"

drivers/platform/x86/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ obj-$(CONFIG_COMPAL_LAPTOP) += compal-laptop.o 
obj-$(CONFIG_DELL_LAPTOP)	+= dell-laptop.o

obj-$(CONFIG_DELL_WMI)		+= dell-wmi.o

obj-$(CONFIG_DELL_WMI_AIO)	+= dell-wmi-aio.o

obj-$(CONFIG_DELL_SMO8800)	+= dell-smo8800.o

obj-$(CONFIG_ACER_WMI)		+= acer-wmi.o

obj-$(CONFIG_ACERHDF)		+= acerhdf.o

obj-$(CONFIG_HP_ACCEL)		+= hp_accel.o

drivers/platform/x86/dell-smo8800.c

0 → 100644
+233 −0
Original line number Diff line number Diff line 
/*

 *  dell-smo8800.c - Dell Latitude ACPI SMO8800/SMO8810 freefall sensor driver

 *

 *  Copyright (C) 2012 Sonal Santan <sonal.santan@gmail.com>

 *  Copyright (C) 2014 Pali Rohár <pali.rohar@gmail.com>

 *

 *  This is loosely based on lis3lv02d driver.

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 */



#define DRIVER_NAME "smo8800"



#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/acpi.h>

#include <linux/interrupt.h>

#include <linux/miscdevice.h>



struct smo8800_device {

	u32 irq;                     /* acpi device irq */

	atomic_t counter;            /* count after last read */

	struct miscdevice miscdev;   /* for /dev/freefall */

	unsigned long misc_opened;   /* whether the device is open */

	wait_queue_head_t misc_wait; /* Wait queue for the misc dev */

	struct device *dev;          /* acpi device */

};



static irqreturn_t smo8800_interrupt_quick(int irq, void *data)

{

	struct smo8800_device *smo8800 = data;



	atomic_inc(&smo8800->counter);

	wake_up_interruptible(&smo8800->misc_wait);

	return IRQ_WAKE_THREAD;

}



static irqreturn_t smo8800_interrupt_thread(int irq, void *data)

{

	struct smo8800_device *smo8800 = data;



	dev_info(smo8800->dev, "detected free fall\n");

	return IRQ_HANDLED;

}



static acpi_status smo8800_get_resource(struct acpi_resource *resource,

					void *context)

{

	struct acpi_resource_extended_irq *irq;



	if (resource->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)

		return AE_OK;



	irq = &resource->data.extended_irq;

	if (!irq || !irq->interrupt_count)

		return AE_OK;



	*((u32 *)context) = irq->interrupts[0];

	return AE_CTRL_TERMINATE;

}



static u32 smo8800_get_irq(struct acpi_device *device)

{

	u32 irq = 0;

	acpi_status status;



	status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,

				     smo8800_get_resource, &irq);

	if (ACPI_FAILURE(status)) {

		dev_err(&device->dev, "acpi_walk_resources failed\n");

		return 0;

	}



	return irq;

}



static ssize_t smo8800_misc_read(struct file *file, char __user *buf,

				 size_t count, loff_t *pos)

{

	struct smo8800_device *smo8800 = container_of(file->private_data,

					 struct smo8800_device, miscdev);



	u32 data = 0;

	unsigned char byte_data = 0;

	ssize_t retval = 1;



	if (count < 1)

		return -EINVAL;



	atomic_set(&smo8800->counter, 0);

	retval = wait_event_interruptible(smo8800->misc_wait,

				(data = atomic_xchg(&smo8800->counter, 0)));



	if (retval)

		return retval;



	byte_data = 1;

	retval = 1;



	if (data < 255)

		byte_data = data;

	else

		byte_data = 255;



	if (put_user(byte_data, buf))

		retval = -EFAULT;



	return retval;

}



static int smo8800_misc_open(struct inode *inode, struct file *file)

{

	struct smo8800_device *smo8800 = container_of(file->private_data,

					 struct smo8800_device, miscdev);



	if (test_and_set_bit(0, &smo8800->misc_opened))

		return -EBUSY; /* already open */



	atomic_set(&smo8800->counter, 0);

	return 0;

}



static int smo8800_misc_release(struct inode *inode, struct file *file)

{

	struct smo8800_device *smo8800 = container_of(file->private_data,

					 struct smo8800_device, miscdev);



	clear_bit(0, &smo8800->misc_opened); /* release the device */

	return 0;

}



static const struct file_operations smo8800_misc_fops = {

	.owner = THIS_MODULE,

	.read = smo8800_misc_read,

	.open = smo8800_misc_open,

	.release = smo8800_misc_release,

};



static int smo8800_add(struct acpi_device *device)

{

	int err;

	struct smo8800_device *smo8800;



	smo8800 = devm_kzalloc(&device->dev, sizeof(*smo8800), GFP_KERNEL);

	if (!smo8800) {

		dev_err(&device->dev, "failed to allocate device data\n");

		return -ENOMEM;

	}



	smo8800->dev = &device->dev;

	smo8800->miscdev.minor = MISC_DYNAMIC_MINOR;

	smo8800->miscdev.name = "freefall";

	smo8800->miscdev.fops = &smo8800_misc_fops;



	init_waitqueue_head(&smo8800->misc_wait);



	err = misc_register(&smo8800->miscdev);

	if (err) {

		dev_err(&device->dev, "failed to register misc dev: %d\n", err);

		return err;

	}



	device->driver_data = smo8800;



	smo8800->irq = smo8800_get_irq(device);

	if (!smo8800->irq) {

		dev_err(&device->dev, "failed to obtain IRQ\n");

		err = -EINVAL;

		goto error;

	}



	err = request_threaded_irq(smo8800->irq, smo8800_interrupt_quick,

				   smo8800_interrupt_thread,

				   IRQF_TRIGGER_RISING | IRQF_ONESHOT,

				   DRIVER_NAME, smo8800);

	if (err) {

		dev_err(&device->dev,

			"failed to request thread for IRQ %d: %d\n",

			smo8800->irq, err);

		goto error;

	}



	dev_dbg(&device->dev, "device /dev/freefall registered with IRQ %d\n",

		 smo8800->irq);

	return 0;



error:

	misc_deregister(&smo8800->miscdev);

	return err;

}



static int smo8800_remove(struct acpi_device *device)

{

	struct smo8800_device *smo8800 = device->driver_data;



	free_irq(smo8800->irq, smo8800);

	misc_deregister(&smo8800->miscdev);

	dev_dbg(&device->dev, "device /dev/freefall unregistered\n");

	return 0;

}



static const struct acpi_device_id smo8800_ids[] = {

	{ "SMO8800", 0 },

	{ "SMO8810", 0 },

	{ "", 0 },

};



MODULE_DEVICE_TABLE(acpi, smo8800_ids);



static struct acpi_driver smo8800_driver = {

	.name = DRIVER_NAME,

	.class = "Latitude",

	.ids = smo8800_ids,

	.ops = {

		.add = smo8800_add,

		.remove = smo8800_remove,

	},

	.owner = THIS_MODULE,

};



module_acpi_driver(smo8800_driver);



MODULE_DESCRIPTION("Dell Latitude freefall driver (ACPI SMO8800/SMO8810)");

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Sonal Santan, Pali Rohár");

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