/* * Apple Motion Sensor driver (I2C variant) * * Copyright (C) 2005 Stelian Pop (stelian@popies.net) * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch) * * Clean room implementation based on the reverse engineered Mac OS X driver by * Johannes Berg , documentation available at * http://johannes.sipsolutions.net/PowerBook/Apple_Motion_Sensor_Specification * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include #include #include #include #include #include "ams.h" /* AMS registers */ #define AMS_COMMAND 0x00 /* command register */ #define AMS_STATUS 0x01 /* status register */ #define AMS_CTRL1 0x02 /* read control 1 (number of values) */ #define AMS_CTRL2 0x03 /* read control 2 (offset?) */ #define AMS_CTRL3 0x04 /* read control 3 (size of each value?) */ #define AMS_DATA1 0x05 /* read data 1 */ #define AMS_DATA2 0x06 /* read data 2 */ #define AMS_DATA3 0x07 /* read data 3 */ #define AMS_DATA4 0x08 /* read data 4 */ #define AMS_DATAX 0x20 /* data X */ #define AMS_DATAY 0x21 /* data Y */ #define AMS_DATAZ 0x22 /* data Z */ #define AMS_FREEFALL 0x24 /* freefall int control */ #define AMS_SHOCK 0x25 /* shock int control */ #define AMS_SENSLOW 0x26 /* sensitivity low limit */ #define AMS_SENSHIGH 0x27 /* sensitivity high limit */ #define AMS_CTRLX 0x28 /* control X */ #define AMS_CTRLY 0x29 /* control Y */ #define AMS_CTRLZ 0x2A /* control Z */ #define AMS_UNKNOWN1 0x2B /* unknown 1 */ #define AMS_UNKNOWN2 0x2C /* unknown 2 */ #define AMS_UNKNOWN3 0x2D /* unknown 3 */ #define AMS_VENDOR 0x2E /* vendor */ /* AMS commands - use with the AMS_COMMAND register */ enum ams_i2c_cmd { AMS_CMD_NOOP = 0, AMS_CMD_VERSION, AMS_CMD_READMEM, AMS_CMD_WRITEMEM, AMS_CMD_ERASEMEM, AMS_CMD_READEE, AMS_CMD_WRITEEE, AMS_CMD_RESET, AMS_CMD_START, }; static int ams_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id); static int ams_i2c_remove(struct i2c_client *client); static const struct i2c_device_id ams_id[] = { { "MAC,accelerometer_1", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, ams_id); static struct i2c_driver ams_i2c_driver = { .driver = { .name = "ams", .owner = THIS_MODULE, }, .probe = ams_i2c_probe, .remove = ams_i2c_remove, .id_table = ams_id, }; static s32 ams_i2c_read(u8 reg) { return i2c_smbus_read_byte_data(ams_info.i2c_client, reg); } static int ams_i2c_write(u8 reg, u8 value) { return i2c_smbus_write_byte_data(ams_info.i2c_client, reg, value); } static int ams_i2c_cmd(enum ams_i2c_cmd cmd) { s32 result; int count = 3; ams_i2c_write(AMS_COMMAND, cmd); msleep(5); while (count--) { result = ams_i2c_read(AMS_COMMAND); if (result == 0 || result & 0x80) return 0; schedule_timeout_uninterruptible(HZ / 20); } return -1; } static void ams_i2c_set_irq(enum ams_irq reg, char enable) { if (reg & AMS_IRQ_FREEFALL) { u8 val = ams_i2c_read(AMS_CTRLX); if (enable) val |= 0x80; else val &= ~0x80; ams_i2c_write(AMS_CTRLX, val); } if (reg & AMS_IRQ_SHOCK) { u8 val = ams_i2c_read(AMS_CTRLY); if (enable) val |= 0x80; else val &= ~0x80; ams_i2c_write(AMS_CTRLY, val); } if (reg & AMS_IRQ_GLOBAL) { u8 val = ams_i2c_read(AMS_CTRLZ); if (enable) val |= 0x80; else val &= ~0x80; ams_i2c_write(AMS_CTRLZ, val); } } static void ams_i2c_clear_irq(enum ams_irq reg) { if (reg & AMS_IRQ_FREEFALL) ams_i2c_write(AMS_FREEFALL, 0); if (reg & AMS_IRQ_SHOCK) ams_i2c_write(AMS_SHOCK, 0); } static u8 ams_i2c_get_vendor(void) { return ams_i2c_read(AMS_VENDOR); } static void ams_i2c_get_xyz(s8 *x, s8 *y, s8 *z) { *x = ams_i2c_read(AMS_DATAX); *y = ams_i2c_read(AMS_DATAY); *z = ams_i2c_read(AMS_DATAZ); } static int ams_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) { int vmaj, vmin; int result; /* There can be only one */ if (unlikely(ams_info.has_device)) return -ENODEV; ams_info.i2c_client = client; if (ams_i2c_cmd(AMS_CMD_RESET)) { printk(KERN_INFO "ams: Failed to reset the device\n"); return -ENODEV; } if (ams_i2c_cmd(AMS_CMD_START)) { printk(KERN_INFO "ams: Failed to start the device\n"); return -ENODEV; } /* get version/vendor information */ ams_i2c_write(AMS_CTRL1, 0x02); ams_i2c_write(AMS_CTRL2, 0x85); ams_i2c_write(AMS_CTRL3, 0x01); ams_i2c_cmd(AMS_CMD_READMEM); vmaj = ams_i2c_read(AMS_DATA1); vmin = ams_i2c_read(AMS_DATA2); if (vmaj != 1 || vmin != 52) { printk(KERN_INFO "ams: Incorrect device version (%d.%d)\n", vmaj, vmin); return -ENODEV; } ams_i2c_cmd(AMS_CMD_VERSION); vmaj = ams_i2c_read(AMS_DATA1); vmin = ams_i2c_read(AMS_DATA2); if (vmaj != 0 || vmin != 1) { printk(KERN_INFO "ams: Incorrect firmware version (%d.%d)\n", vmaj, vmin); return -ENODEV; } /* Disable interrupts */ ams_i2c_set_irq(AMS_IRQ_ALL, 0); result = ams_sensor_attach(); if (result < 0) return result; /* Set default values */ ams_i2c_write(AMS_SENSLOW, 0x15); ams_i2c_write(AMS_SENSHIGH, 0x60); ams_i2c_write(AMS_CTRLX, 0x08); ams_i2c_write(AMS_CTRLY, 0x0F); ams_i2c_write(AMS_CTRLZ, 0x4F); ams_i2c_write(AMS_UNKNOWN1, 0x14); /* Clear interrupts */ ams_i2c_clear_irq(AMS_IRQ_ALL); ams_info.has_device = 1; /* Enable interrupts */ ams_i2c_set_irq(AMS_IRQ_ALL, 1); printk(KERN_INFO "ams: Found I2C based motion sensor\n"); return 0; } static int ams_i2c_remove(struct i2c_client *client) { if (ams_info.has_device) { ams_sensor_detach(); /* Disable interrupts */ ams_i2c_set_irq(AMS_IRQ_ALL, 0); /* Clear interrupts */ ams_i2c_clear_irq(AMS_IRQ_ALL); printk(KERN_INFO "ams: Unloading\n"); ams_info.has_device = 0; } return 0; } static void ams_i2c_exit(void) { i2c_del_driver(&ams_i2c_driver); } int __init ams_i2c_init(struct device_node *np) { int result; /* Set implementation stuff */ ams_info.of_node = np; ams_info.exit = ams_i2c_exit; ams_info.get_vendor = ams_i2c_get_vendor; ams_info.get_xyz = ams_i2c_get_xyz; ams_info.clear_irq = ams_i2c_clear_irq; ams_info.bustype = BUS_I2C; result = i2c_add_driver(&ams_i2c_driver); return result; }