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 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 */ 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 */ 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 */ 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 } 108 109 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 } 117 118 static u8 ams_pmu_get_vendor(void) 119 { 120 return ams_pmu_get_register(AMS_VENDOR); 121 } 122 123 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 } 129 130 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 } 144 145 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