1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Apple Motion Sensor driver (PMU variant)
4 *
5 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
6 */
7
8 #include <linux/module.h>
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/init.h>
12 #include <linux/adb.h>
13 #include <linux/pmu.h>
14
15 #include "ams.h"
16
17 /* Attitude */
18 #define AMS_X 0x00
19 #define AMS_Y 0x01
20 #define AMS_Z 0x02
21
22 /* Not exactly known, maybe chip vendor */
23 #define AMS_VENDOR 0x03
24
25 /* Freefall registers */
26 #define AMS_FF_CLEAR 0x04
27 #define AMS_FF_ENABLE 0x05
28 #define AMS_FF_LOW_LIMIT 0x06
29 #define AMS_FF_DEBOUNCE 0x07
30
31 /* Shock registers */
32 #define AMS_SHOCK_CLEAR 0x08
33 #define AMS_SHOCK_ENABLE 0x09
34 #define AMS_SHOCK_HIGH_LIMIT 0x0a
35 #define AMS_SHOCK_DEBOUNCE 0x0b
36
37 /* Global interrupt and power control register */
38 #define AMS_CONTROL 0x0c
39
40 static u8 ams_pmu_cmd;
41
ams_pmu_req_complete(struct adb_request * req)42 static void ams_pmu_req_complete(struct adb_request *req)
43 {
44 complete((struct completion *)req->arg);
45 }
46
47 /* Only call this function from task context */
ams_pmu_set_register(u8 reg,u8 value)48 static void ams_pmu_set_register(u8 reg, u8 value)
49 {
50 static struct adb_request req;
51 DECLARE_COMPLETION(req_complete);
52
53 req.arg = &req_complete;
54 if (pmu_request(&req, ams_pmu_req_complete, 4, ams_pmu_cmd, 0x00, reg, value))
55 return;
56
57 wait_for_completion(&req_complete);
58 }
59
60 /* Only call this function from task context */
ams_pmu_get_register(u8 reg)61 static u8 ams_pmu_get_register(u8 reg)
62 {
63 static struct adb_request req;
64 DECLARE_COMPLETION(req_complete);
65
66 req.arg = &req_complete;
67 if (pmu_request(&req, ams_pmu_req_complete, 3, ams_pmu_cmd, 0x01, reg))
68 return 0;
69
70 wait_for_completion(&req_complete);
71
72 if (req.reply_len > 0)
73 return req.reply[0];
74 else
75 return 0;
76 }
77
78 /* Enables or disables the specified interrupts */
ams_pmu_set_irq(enum ams_irq reg,char enable)79 static void ams_pmu_set_irq(enum ams_irq reg, char enable)
80 {
81 if (reg & AMS_IRQ_FREEFALL) {
82 u8 val = ams_pmu_get_register(AMS_FF_ENABLE);
83 if (enable)
84 val |= 0x80;
85 else
86 val &= ~0x80;
87 ams_pmu_set_register(AMS_FF_ENABLE, val);
88 }
89
90 if (reg & AMS_IRQ_SHOCK) {
91 u8 val = ams_pmu_get_register(AMS_SHOCK_ENABLE);
92 if (enable)
93 val |= 0x80;
94 else
95 val &= ~0x80;
96 ams_pmu_set_register(AMS_SHOCK_ENABLE, val);
97 }
98
99 if (reg & AMS_IRQ_GLOBAL) {
100 u8 val = ams_pmu_get_register(AMS_CONTROL);
101 if (enable)
102 val |= 0x80;
103 else
104 val &= ~0x80;
105 ams_pmu_set_register(AMS_CONTROL, val);
106 }
107 }
108
ams_pmu_clear_irq(enum ams_irq reg)109 static void ams_pmu_clear_irq(enum ams_irq reg)
110 {
111 if (reg & AMS_IRQ_FREEFALL)
112 ams_pmu_set_register(AMS_FF_CLEAR, 0x00);
113
114 if (reg & AMS_IRQ_SHOCK)
115 ams_pmu_set_register(AMS_SHOCK_CLEAR, 0x00);
116 }
117
ams_pmu_get_vendor(void)118 static u8 ams_pmu_get_vendor(void)
119 {
120 return ams_pmu_get_register(AMS_VENDOR);
121 }
122
ams_pmu_get_xyz(s8 * x,s8 * y,s8 * z)123 static void ams_pmu_get_xyz(s8 *x, s8 *y, s8 *z)
124 {
125 *x = ams_pmu_get_register(AMS_X);
126 *y = ams_pmu_get_register(AMS_Y);
127 *z = ams_pmu_get_register(AMS_Z);
128 }
129
ams_pmu_exit(void)130 static void ams_pmu_exit(void)
131 {
132 ams_sensor_detach();
133
134 /* Disable interrupts */
135 ams_pmu_set_irq(AMS_IRQ_ALL, 0);
136
137 /* Clear interrupts */
138 ams_pmu_clear_irq(AMS_IRQ_ALL);
139
140 ams_info.has_device = 0;
141
142 printk(KERN_INFO "ams: Unloading\n");
143 }
144
ams_pmu_init(struct device_node * np)145 int __init ams_pmu_init(struct device_node *np)
146 {
147 const u32 *prop;
148 int result;
149
150 /* Set implementation stuff */
151 ams_info.of_node = np;
152 ams_info.exit = ams_pmu_exit;
153 ams_info.get_vendor = ams_pmu_get_vendor;
154 ams_info.get_xyz = ams_pmu_get_xyz;
155 ams_info.clear_irq = ams_pmu_clear_irq;
156 ams_info.bustype = BUS_HOST;
157
158 /* Get PMU command, should be 0x4e, but we can never know */
159 prop = of_get_property(ams_info.of_node, "reg", NULL);
160 if (!prop)
161 return -ENODEV;
162
163 ams_pmu_cmd = ((*prop) >> 8) & 0xff;
164
165 /* Disable interrupts */
166 ams_pmu_set_irq(AMS_IRQ_ALL, 0);
167
168 /* Clear interrupts */
169 ams_pmu_clear_irq(AMS_IRQ_ALL);
170
171 result = ams_sensor_attach();
172 if (result < 0)
173 return result;
174
175 /* Set default values */
176 ams_pmu_set_register(AMS_FF_LOW_LIMIT, 0x15);
177 ams_pmu_set_register(AMS_FF_ENABLE, 0x08);
178 ams_pmu_set_register(AMS_FF_DEBOUNCE, 0x14);
179
180 ams_pmu_set_register(AMS_SHOCK_HIGH_LIMIT, 0x60);
181 ams_pmu_set_register(AMS_SHOCK_ENABLE, 0x0f);
182 ams_pmu_set_register(AMS_SHOCK_DEBOUNCE, 0x14);
183
184 ams_pmu_set_register(AMS_CONTROL, 0x4f);
185
186 /* Clear interrupts */
187 ams_pmu_clear_irq(AMS_IRQ_ALL);
188
189 ams_info.has_device = 1;
190
191 /* Enable interrupts */
192 ams_pmu_set_irq(AMS_IRQ_ALL, 1);
193
194 printk(KERN_INFO "ams: Found PMU based motion sensor\n");
195
196 return 0;
197 }
198