ams-pmu.c

  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
 40static u8 ams_pmu_cmd;
 41
 42static 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 */
 48static 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 */
 61static 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 */
 79static 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
109static 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
118static u8 ams_pmu_get_vendor(void)
119{
120	return ams_pmu_get_register(AMS_VENDOR);
121}
122
123static 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
130static 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
145int __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}