ams-pmu.c revision 40cd3a4564ed6b7bc0279430120ca0e9b83cf486 
1/*
2 * Apple Motion Sensor driver (PMU variant)
3 *
4 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/types.h>
14#include <linux/errno.h>
15#include <linux/init.h>
16#include <linux/adb.h>
17#include <linux/pmu.h>
18
19#include "ams.h"
20
21/* Attitude */
22#define AMS_X			0x00
23#define AMS_Y			0x01
24#define AMS_Z			0x02
25
26/* Not exactly known, maybe chip vendor */
27#define AMS_VENDOR		0x03
28
29/* Freefall registers */
30#define AMS_FF_CLEAR		0x04
31#define AMS_FF_ENABLE		0x05
32#define AMS_FF_LOW_LIMIT	0x06
33#define AMS_FF_DEBOUNCE		0x07
34
35/* Shock registers */
36#define AMS_SHOCK_CLEAR		0x08
37#define AMS_SHOCK_ENABLE	0x09
38#define AMS_SHOCK_HIGH_LIMIT	0x0a
39#define AMS_SHOCK_DEBOUNCE	0x0b
40
41/* Global interrupt and power control register */
42#define AMS_CONTROL		0x0c
43
44static u8 ams_pmu_cmd;
45
46static void ams_pmu_req_complete(struct adb_request *req)
47{
48	complete((struct completion *)req->arg);
49}
50
51/* Only call this function from task context */
52static void ams_pmu_set_register(u8 reg, u8 value)
53{
54	static struct adb_request req;
55	DECLARE_COMPLETION(req_complete);
56
57	req.arg = &req_complete;
58	if (pmu_request(&req, ams_pmu_req_complete, 4, ams_pmu_cmd, 0x00, reg, value))
59		return;
60
61	wait_for_completion(&req_complete);
62}
63
64/* Only call this function from task context */
65static u8 ams_pmu_get_register(u8 reg)
66{
67	static struct adb_request req;
68	DECLARE_COMPLETION(req_complete);
69
70	req.arg = &req_complete;
71	if (pmu_request(&req, ams_pmu_req_complete, 3, ams_pmu_cmd, 0x01, reg))
72		return 0;
73
74	wait_for_completion(&req_complete);
75
76	if (req.reply_len > 0)
77		return req.reply[0];
78	else
79		return 0;
80}
81
82/* Enables or disables the specified interrupts */
83static void ams_pmu_set_irq(enum ams_irq reg, char enable)
84{
85	if (reg & AMS_IRQ_FREEFALL) {
86		u8 val = ams_pmu_get_register(AMS_FF_ENABLE);
87		if (enable)
88			val |= 0x80;
89		else
90			val &= ~0x80;
91		ams_pmu_set_register(AMS_FF_ENABLE, val);
92	}
93
94	if (reg & AMS_IRQ_SHOCK) {
95		u8 val = ams_pmu_get_register(AMS_SHOCK_ENABLE);
96		if (enable)
97			val |= 0x80;
98		else
99			val &= ~0x80;
100		ams_pmu_set_register(AMS_SHOCK_ENABLE, val);
101	}
102
103	if (reg & AMS_IRQ_GLOBAL) {
104		u8 val = ams_pmu_get_register(AMS_CONTROL);
105		if (enable)
106			val |= 0x80;
107		else
108			val &= ~0x80;
109		ams_pmu_set_register(AMS_CONTROL, val);
110	}
111}
112
113static void ams_pmu_clear_irq(enum ams_irq reg)
114{
115	if (reg & AMS_IRQ_FREEFALL)
116		ams_pmu_set_register(AMS_FF_CLEAR, 0x00);
117
118	if (reg & AMS_IRQ_SHOCK)
119		ams_pmu_set_register(AMS_SHOCK_CLEAR, 0x00);
120}
121
122static u8 ams_pmu_get_vendor(void)
123{
124	return ams_pmu_get_register(AMS_VENDOR);
125}
126
127static void ams_pmu_get_xyz(s8 *x, s8 *y, s8 *z)
128{
129	*x = ams_pmu_get_register(AMS_X);
130	*y = ams_pmu_get_register(AMS_Y);
131	*z = ams_pmu_get_register(AMS_Z);
132}
133
134static void ams_pmu_exit(void)
135{
136	/* Disable interrupts */
137	ams_pmu_set_irq(AMS_IRQ_ALL, 0);
138
139	/* Clear interrupts */
140	ams_pmu_clear_irq(AMS_IRQ_ALL);
141
142	ams_info.has_device = 0;
143
144	printk(KERN_INFO "ams: Unloading\n");
145}
146
147int __init ams_pmu_init(struct device_node *np)
148{
149	const u32 *prop;
150	int result;
151
152	mutex_lock(&ams_info.lock);
153
154	/* Set implementation stuff */
155	ams_info.of_node = np;
156	ams_info.exit = ams_pmu_exit;
157	ams_info.get_vendor = ams_pmu_get_vendor;
158	ams_info.get_xyz = ams_pmu_get_xyz;
159	ams_info.clear_irq = ams_pmu_clear_irq;
160	ams_info.bustype = BUS_HOST;
161
162	/* Get PMU command, should be 0x4e, but we can never know */
163	prop = of_get_property(ams_info.of_node, "reg", NULL);
164	if (!prop) {
165		result = -ENODEV;
166		goto exit;
167	}
168	ams_pmu_cmd = ((*prop) >> 8) & 0xff;
169
170	/* Disable interrupts */
171	ams_pmu_set_irq(AMS_IRQ_ALL, 0);
172
173	/* Clear interrupts */
174	ams_pmu_clear_irq(AMS_IRQ_ALL);
175
176	result = ams_sensor_attach();
177	if (result < 0)
178		goto exit;
179
180	/* Set default values */
181	ams_pmu_set_register(AMS_FF_LOW_LIMIT, 0x15);
182	ams_pmu_set_register(AMS_FF_ENABLE, 0x08);
183	ams_pmu_set_register(AMS_FF_DEBOUNCE, 0x14);
184
185	ams_pmu_set_register(AMS_SHOCK_HIGH_LIMIT, 0x60);
186	ams_pmu_set_register(AMS_SHOCK_ENABLE, 0x0f);
187	ams_pmu_set_register(AMS_SHOCK_DEBOUNCE, 0x14);
188
189	ams_pmu_set_register(AMS_CONTROL, 0x4f);
190
191	/* Clear interrupts */
192	ams_pmu_clear_irq(AMS_IRQ_ALL);
193
194	ams_info.has_device = 1;
195
196	/* Enable interrupts */
197	ams_pmu_set_irq(AMS_IRQ_ALL, 1);
198
199	printk(KERN_INFO "ams: Found PMU based motion sensor\n");
200
201	result = 0;
202
203exit:
204	mutex_unlock(&ams_info.lock);
205
206	return result;
207}
208