1 // SPDX-License-Identifier: GPL-2.0-or-later
3  *  dell-smo8800.c - Dell Latitude ACPI SMO88XX freefall sensor driver
22 	u32 irq;                     /* acpi device irq */  member
25 	unsigned long misc_opened;   /* whether the device is open */
27 	struct device *dev;          /* acpi device */
30 static irqreturn_t smo8800_interrupt_quick(int irq, void *data)  in smo8800_interrupt_quick()  argument
34 	atomic_inc(&smo8800->counter);  in smo8800_interrupt_quick()
35 	wake_up_interruptible(&smo8800->misc_wait);  in smo8800_interrupt_quick()
39 static irqreturn_t smo8800_interrupt_thread(int irq, void *data)  in smo8800_interrupt_thread()  argument
43 	dev_info(smo8800->dev, "detected free fall\n");  in smo8800_interrupt_thread()
50 	struct acpi_resource_extended_irq *irq;  in smo8800_get_resource()  local
52 	if (resource->type != ACPI_RESOURCE_TYPE_EXTENDED_IRQ)  in smo8800_get_resource()
55 	irq = &resource->data.extended_irq;  in smo8800_get_resource()
56 	if (!irq || !irq->interrupt_count)  in smo8800_get_resource()
59 	*((u32 *)context) = irq->interrupts[0];  in smo8800_get_resource()
63 static u32 smo8800_get_irq(struct acpi_device *device)  in smo8800_get_irq()  argument
65 	u32 irq = 0;  in smo8800_get_irq()  local
68 	status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,  in smo8800_get_irq()
69 				     smo8800_get_resource, &irq);  in smo8800_get_irq()
71 		dev_err(&device->dev, "acpi_walk_resources failed\n");  in smo8800_get_irq()
75 	return irq;  in smo8800_get_irq()
81 	struct smo8800_device *smo8800 = container_of(file->private_data,  in smo8800_misc_read()
89 		return -EINVAL;  in smo8800_misc_read()
91 	atomic_set(&smo8800->counter, 0);  in smo8800_misc_read()
92 	retval = wait_event_interruptible(smo8800->misc_wait,  in smo8800_misc_read()
93 				(data = atomic_xchg(&smo8800->counter, 0)));  in smo8800_misc_read()
106 		retval = -EFAULT;  in smo8800_misc_read()
113 	struct smo8800_device *smo8800 = container_of(file->private_data,  in smo8800_misc_open()
116 	if (test_and_set_bit(0, &smo8800->misc_opened))  in smo8800_misc_open()
117 		return -EBUSY; /* already open */  in smo8800_misc_open()
119 	atomic_set(&smo8800->counter, 0);  in smo8800_misc_open()
125 	struct smo8800_device *smo8800 = container_of(file->private_data,  in smo8800_misc_release()
128 	clear_bit(0, &smo8800->misc_opened); /* release the device */  in smo8800_misc_release()
139 static int smo8800_add(struct acpi_device *device)  in smo8800_add()  argument
144 	smo8800 = devm_kzalloc(&device->dev, sizeof(*smo8800), GFP_KERNEL);  in smo8800_add()
146 		dev_err(&device->dev, "failed to allocate device data\n");  in smo8800_add()
147 		return -ENOMEM;  in smo8800_add()
150 	smo8800->dev = &device->dev;  in smo8800_add()
151 	smo8800->miscdev.minor = MISC_DYNAMIC_MINOR;  in smo8800_add()
152 	smo8800->miscdev.name = "freefall";  in smo8800_add()
153 	smo8800->miscdev.fops = &smo8800_misc_fops;  in smo8800_add()
155 	init_waitqueue_head(&smo8800->misc_wait);  in smo8800_add()
157 	err = misc_register(&smo8800->miscdev);  in smo8800_add()
159 		dev_err(&device->dev, "failed to register misc dev: %d\n", err);  in smo8800_add()
163 	device->driver_data = smo8800;  in smo8800_add()
165 	smo8800->irq = smo8800_get_irq(device);  in smo8800_add()
166 	if (!smo8800->irq) {  in smo8800_add()
167 		dev_err(&device->dev, "failed to obtain IRQ\n");  in smo8800_add()
168 		err = -EINVAL;  in smo8800_add()
172 	err = request_threaded_irq(smo8800->irq, smo8800_interrupt_quick,  in smo8800_add()
177 		dev_err(&device->dev,  in smo8800_add()
178 			"failed to request thread for IRQ %d: %d\n",  in smo8800_add()
179 			smo8800->irq, err);  in smo8800_add()
183 	dev_dbg(&device->dev, "device /dev/freefall registered with IRQ %d\n",  in smo8800_add()
184 		 smo8800->irq);  in smo8800_add()
188 	misc_deregister(&smo8800->miscdev);  in smo8800_add()
192 static int smo8800_remove(struct acpi_device *device)  in smo8800_remove()  argument
194 	struct smo8800_device *smo8800 = device->driver_data;  in smo8800_remove()
196 	free_irq(smo8800->irq, smo8800);  in smo8800_remove()
197 	misc_deregister(&smo8800->miscdev);  in smo8800_remove()
198 	dev_dbg(&device->dev, "device /dev/freefall unregistered\n");  in smo8800_remove()
202 /* NOTE: Keep this list in sync with drivers/i2c/busses/i2c-i801.c */