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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Apple Motion Sensor driver (I2C variant)4 *5 * Copyright (C) 2005 Stelian Pop (stelian@popies.net)6 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)7 *8 * Clean room implementation based on the reverse engineered Mac OS X driver by9 * Johannes Berg <johannes@sipsolutions.net>, documentation available at10 * http://johannes.sipsolutions.net/PowerBook/Apple_Motion_Sensor_Specification11 */12 13#include <linux/module.h>14#include <linux/types.h>15#include <linux/errno.h>16#include <linux/init.h>17#include <linux/delay.h>18 19#include "ams.h"20 21/* AMS registers */22#define AMS_COMMAND 0x00 /* command register */23#define AMS_STATUS 0x01 /* status register */24#define AMS_CTRL1 0x02 /* read control 1 (number of values) */25#define AMS_CTRL2 0x03 /* read control 2 (offset?) */26#define AMS_CTRL3 0x04 /* read control 3 (size of each value?) */27#define AMS_DATA1 0x05 /* read data 1 */28#define AMS_DATA2 0x06 /* read data 2 */29#define AMS_DATA3 0x07 /* read data 3 */30#define AMS_DATA4 0x08 /* read data 4 */31#define AMS_DATAX 0x20 /* data X */32#define AMS_DATAY 0x21 /* data Y */33#define AMS_DATAZ 0x22 /* data Z */34#define AMS_FREEFALL 0x24 /* freefall int control */35#define AMS_SHOCK 0x25 /* shock int control */36#define AMS_SENSLOW 0x26 /* sensitivity low limit */37#define AMS_SENSHIGH 0x27 /* sensitivity high limit */38#define AMS_CTRLX 0x28 /* control X */39#define AMS_CTRLY 0x29 /* control Y */40#define AMS_CTRLZ 0x2A /* control Z */41#define AMS_UNKNOWN1 0x2B /* unknown 1 */42#define AMS_UNKNOWN2 0x2C /* unknown 2 */43#define AMS_UNKNOWN3 0x2D /* unknown 3 */44#define AMS_VENDOR 0x2E /* vendor */45 46/* AMS commands - use with the AMS_COMMAND register */47enum ams_i2c_cmd {48 AMS_CMD_NOOP = 0,49 AMS_CMD_VERSION,50 AMS_CMD_READMEM,51 AMS_CMD_WRITEMEM,52 AMS_CMD_ERASEMEM,53 AMS_CMD_READEE,54 AMS_CMD_WRITEEE,55 AMS_CMD_RESET,56 AMS_CMD_START,57};58 59static int ams_i2c_probe(struct i2c_client *client);60static void ams_i2c_remove(struct i2c_client *client);61 62static const struct i2c_device_id ams_id[] = {63 { "MAC,accelerometer_1" },64 { }65};66MODULE_DEVICE_TABLE(i2c, ams_id);67 68static struct i2c_driver ams_i2c_driver = {69 .driver = {70 .name = "ams",71 },72 .probe = ams_i2c_probe,73 .remove = ams_i2c_remove,74 .id_table = ams_id,75};76 77static s32 ams_i2c_read(u8 reg)78{79 return i2c_smbus_read_byte_data(ams_info.i2c_client, reg);80}81 82static int ams_i2c_write(u8 reg, u8 value)83{84 return i2c_smbus_write_byte_data(ams_info.i2c_client, reg, value);85}86 87static int ams_i2c_cmd(enum ams_i2c_cmd cmd)88{89 s32 result;90 int count = 3;91 92 ams_i2c_write(AMS_COMMAND, cmd);93 msleep(5);94 95 while (count--) {96 result = ams_i2c_read(AMS_COMMAND);97 if (result == 0 || result & 0x80)98 return 0;99 100 schedule_timeout_uninterruptible(HZ / 20);101 }102 103 return -1;104}105 106static void ams_i2c_set_irq(enum ams_irq reg, char enable)107{108 if (reg & AMS_IRQ_FREEFALL) {109 u8 val = ams_i2c_read(AMS_CTRLX);110 if (enable)111 val |= 0x80;112 else113 val &= ~0x80;114 ams_i2c_write(AMS_CTRLX, val);115 }116 117 if (reg & AMS_IRQ_SHOCK) {118 u8 val = ams_i2c_read(AMS_CTRLY);119 if (enable)120 val |= 0x80;121 else122 val &= ~0x80;123 ams_i2c_write(AMS_CTRLY, val);124 }125 126 if (reg & AMS_IRQ_GLOBAL) {127 u8 val = ams_i2c_read(AMS_CTRLZ);128 if (enable)129 val |= 0x80;130 else131 val &= ~0x80;132 ams_i2c_write(AMS_CTRLZ, val);133 }134}135 136static void ams_i2c_clear_irq(enum ams_irq reg)137{138 if (reg & AMS_IRQ_FREEFALL)139 ams_i2c_write(AMS_FREEFALL, 0);140 141 if (reg & AMS_IRQ_SHOCK)142 ams_i2c_write(AMS_SHOCK, 0);143}144 145static u8 ams_i2c_get_vendor(void)146{147 return ams_i2c_read(AMS_VENDOR);148}149 150static void ams_i2c_get_xyz(s8 *x, s8 *y, s8 *z)151{152 *x = ams_i2c_read(AMS_DATAX);153 *y = ams_i2c_read(AMS_DATAY);154 *z = ams_i2c_read(AMS_DATAZ);155}156 157static int ams_i2c_probe(struct i2c_client *client)158{159 int vmaj, vmin;160 int result;161 162 /* There can be only one */163 if (unlikely(ams_info.has_device))164 return -ENODEV;165 166 ams_info.i2c_client = client;167 168 if (ams_i2c_cmd(AMS_CMD_RESET)) {169 printk(KERN_INFO "ams: Failed to reset the device\n");170 return -ENODEV;171 }172 173 if (ams_i2c_cmd(AMS_CMD_START)) {174 printk(KERN_INFO "ams: Failed to start the device\n");175 return -ENODEV;176 }177 178 /* get version/vendor information */179 ams_i2c_write(AMS_CTRL1, 0x02);180 ams_i2c_write(AMS_CTRL2, 0x85);181 ams_i2c_write(AMS_CTRL3, 0x01);182 183 ams_i2c_cmd(AMS_CMD_READMEM);184 185 vmaj = ams_i2c_read(AMS_DATA1);186 vmin = ams_i2c_read(AMS_DATA2);187 if (vmaj != 1 || vmin != 52) {188 printk(KERN_INFO "ams: Incorrect device version (%d.%d)\n",189 vmaj, vmin);190 return -ENODEV;191 }192 193 ams_i2c_cmd(AMS_CMD_VERSION);194 195 vmaj = ams_i2c_read(AMS_DATA1);196 vmin = ams_i2c_read(AMS_DATA2);197 if (vmaj != 0 || vmin != 1) {198 printk(KERN_INFO "ams: Incorrect firmware version (%d.%d)\n",199 vmaj, vmin);200 return -ENODEV;201 }202 203 /* Disable interrupts */204 ams_i2c_set_irq(AMS_IRQ_ALL, 0);205 206 result = ams_sensor_attach();207 if (result < 0)208 return result;209 210 /* Set default values */211 ams_i2c_write(AMS_SENSLOW, 0x15);212 ams_i2c_write(AMS_SENSHIGH, 0x60);213 ams_i2c_write(AMS_CTRLX, 0x08);214 ams_i2c_write(AMS_CTRLY, 0x0F);215 ams_i2c_write(AMS_CTRLZ, 0x4F);216 ams_i2c_write(AMS_UNKNOWN1, 0x14);217 218 /* Clear interrupts */219 ams_i2c_clear_irq(AMS_IRQ_ALL);220 221 ams_info.has_device = 1;222 223 /* Enable interrupts */224 ams_i2c_set_irq(AMS_IRQ_ALL, 1);225 226 printk(KERN_INFO "ams: Found I2C based motion sensor\n");227 228 return 0;229}230 231static void ams_i2c_remove(struct i2c_client *client)232{233 if (ams_info.has_device) {234 ams_sensor_detach();235 236 /* Disable interrupts */237 ams_i2c_set_irq(AMS_IRQ_ALL, 0);238 239 /* Clear interrupts */240 ams_i2c_clear_irq(AMS_IRQ_ALL);241 242 printk(KERN_INFO "ams: Unloading\n");243 244 ams_info.has_device = 0;245 }246}247 248static void ams_i2c_exit(void)249{250 i2c_del_driver(&ams_i2c_driver);251}252 253int __init ams_i2c_init(struct device_node *np)254{255 /* Set implementation stuff */256 ams_info.of_node = np;257 ams_info.exit = ams_i2c_exit;258 ams_info.get_vendor = ams_i2c_get_vendor;259 ams_info.get_xyz = ams_i2c_get_xyz;260 ams_info.clear_irq = ams_i2c_clear_irq;261 ams_info.bustype = BUS_I2C;262 263 return i2c_add_driver(&ams_i2c_driver);264}265