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