ams-core.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Apple Motion Sensor driver
  4 *
  5 * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
  6 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
  7 */
  8
  9#include <linux/module.h>
 10#include <linux/types.h>
 11#include <linux/errno.h>
 12#include <linux/init.h>
 13#include <linux/of_platform.h>
 14#include <asm/pmac_pfunc.h>
 15
 16#include "ams.h"
 17
 18/* There is only one motion sensor per machine */
 19struct ams ams_info;
 20
 21static bool verbose;
 22module_param(verbose, bool, 0644);
 23MODULE_PARM_DESC(verbose, "Show free falls and shocks in kernel output");
 24
 25/* Call with ams_info.lock held! */
 26void ams_sensors(s8 *x, s8 *y, s8 *z)
 27{
 28	u32 orient = ams_info.vflag? ams_info.orient1 : ams_info.orient2;
 29
 30	if (orient & 0x80)
 31		/* X and Y swapped */
 32		ams_info.get_xyz(y, x, z);
 33	else
 34		ams_info.get_xyz(x, y, z);
 35
 36	if (orient & 0x04)
 37		*z = ~(*z);
 38	if (orient & 0x02)
 39		*y = ~(*y);
 40	if (orient & 0x01)
 41		*x = ~(*x);
 42}
 43
 44static ssize_t ams_show_current(struct device *dev,
 45	struct device_attribute *attr, char *buf)
 46{
 47	s8 x, y, z;
 48
 49	mutex_lock(&ams_info.lock);
 50	ams_sensors(&x, &y, &z);
 51	mutex_unlock(&ams_info.lock);
 52
 53	return sysfs_emit(buf, "%d %d %d\n", x, y, z);
 54}
 55
 56static DEVICE_ATTR(current, S_IRUGO, ams_show_current, NULL);
 57
 58static void ams_handle_irq(void *data)
 59{
 60	enum ams_irq irq = *((enum ams_irq *)data);
 61
 62	spin_lock(&ams_info.irq_lock);
 63
 64	ams_info.worker_irqs |= irq;
 65	schedule_work(&ams_info.worker);
 66
 67	spin_unlock(&ams_info.irq_lock);
 68}
 69
 70static enum ams_irq ams_freefall_irq_data = AMS_IRQ_FREEFALL;
 71static struct pmf_irq_client ams_freefall_client = {
 72	.owner = THIS_MODULE,
 73	.handler = ams_handle_irq,
 74	.data = &ams_freefall_irq_data,
 75};
 76
 77static enum ams_irq ams_shock_irq_data = AMS_IRQ_SHOCK;
 78static struct pmf_irq_client ams_shock_client = {
 79	.owner = THIS_MODULE,
 80	.handler = ams_handle_irq,
 81	.data = &ams_shock_irq_data,
 82};
 83
 84/* Once hard disk parking is implemented in the kernel, this function can
 85 * trigger it.
 86 */
 87static void ams_worker(struct work_struct *work)
 88{
 89	unsigned long flags;
 90	u8 irqs_to_clear;
 91
 92	mutex_lock(&ams_info.lock);
 93
 94	spin_lock_irqsave(&ams_info.irq_lock, flags);
 95	irqs_to_clear = ams_info.worker_irqs;
 96
 97	if (ams_info.worker_irqs & AMS_IRQ_FREEFALL) {
 98		if (verbose)
 99			printk(KERN_INFO "ams: freefall detected!\n");
100
101		ams_info.worker_irqs &= ~AMS_IRQ_FREEFALL;
102	}
103
104	if (ams_info.worker_irqs & AMS_IRQ_SHOCK) {
105		if (verbose)
106			printk(KERN_INFO "ams: shock detected!\n");
107
108		ams_info.worker_irqs &= ~AMS_IRQ_SHOCK;
109	}
110
111	spin_unlock_irqrestore(&ams_info.irq_lock, flags);
112
113	ams_info.clear_irq(irqs_to_clear);
114
115	mutex_unlock(&ams_info.lock);
116}
117
118/* Call with ams_info.lock held! */
119int ams_sensor_attach(void)
120{
121	int result;
122	const u32 *prop;
123
124	/* Get orientation */
125	prop = of_get_property(ams_info.of_node, "orientation", NULL);
126	if (!prop)
127		return -ENODEV;
128	ams_info.orient1 = *prop;
129	ams_info.orient2 = *(prop + 1);
130
131	/* Register freefall interrupt handler */
132	result = pmf_register_irq_client(ams_info.of_node,
133			"accel-int-1",
134			&ams_freefall_client);
135	if (result < 0)
136		return -ENODEV;
137
138	/* Reset saved irqs */
139	ams_info.worker_irqs = 0;
140
141	/* Register shock interrupt handler */
142	result = pmf_register_irq_client(ams_info.of_node,
143			"accel-int-2",
144			&ams_shock_client);
145	if (result < 0)
146		goto release_freefall;
147
148	/* Create device */
149	ams_info.of_dev = of_platform_device_create(ams_info.of_node, "ams", NULL);
150	if (!ams_info.of_dev) {
151		result = -ENODEV;
152		goto release_shock;
153	}
154
155	/* Create attributes */
156	result = device_create_file(&ams_info.of_dev->dev, &dev_attr_current);
157	if (result)
158		goto release_of;
159
160	ams_info.vflag = !!(ams_info.get_vendor() & 0x10);
161
162	/* Init input device */
163	result = ams_input_init();
164	if (result)
165		goto release_device_file;
166
167	return result;
168release_device_file:
169	device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
170release_of:
171	of_device_unregister(ams_info.of_dev);
172release_shock:
173	pmf_unregister_irq_client(&ams_shock_client);
174release_freefall:
175	pmf_unregister_irq_client(&ams_freefall_client);
176	return result;
177}
178
179static int __init ams_init(void)
180{
181	struct device_node *np;
182
183	spin_lock_init(&ams_info.irq_lock);
184	mutex_init(&ams_info.lock);
185	INIT_WORK(&ams_info.worker, ams_worker);
186
187#ifdef CONFIG_SENSORS_AMS_I2C
188	np = of_find_node_by_name(NULL, "accelerometer");
189	if (np && of_device_is_compatible(np, "AAPL,accelerometer_1"))
190		/* Found I2C motion sensor */
191		return ams_i2c_init(np);
192#endif
193
194#ifdef CONFIG_SENSORS_AMS_PMU
195	np = of_find_node_by_name(NULL, "sms");
196	if (np && of_device_is_compatible(np, "sms"))
197		/* Found PMU motion sensor */
198		return ams_pmu_init(np);
199#endif
200	return -ENODEV;
201}
202
203void ams_sensor_detach(void)
204{
205	/* Remove input device */
206	ams_input_exit();
207
208	/* Remove attributes */
209	device_remove_file(&ams_info.of_dev->dev, &dev_attr_current);
210
211	/* Flush interrupt worker
212	 *
213	 * We do this after ams_info.exit(), because an interrupt might
214	 * have arrived before disabling them.
215	 */
216	flush_work(&ams_info.worker);
217
218	/* Remove device */
219	of_device_unregister(ams_info.of_dev);
220
221	/* Remove handler */
222	pmf_unregister_irq_client(&ams_shock_client);
223	pmf_unregister_irq_client(&ams_freefall_client);
224}
225
226static void __exit ams_exit(void)
227{
228	/* Shut down implementation */
229	ams_info.exit();
230}
231
232MODULE_AUTHOR("Stelian Pop, Michael Hanselmann");
233MODULE_DESCRIPTION("Apple Motion Sensor driver");
234MODULE_LICENSE("GPL");
235
236module_init(ams_init);
237module_exit(ams_exit);