1 /** 2 * IIO driver for the MiraMEMS DA280 3-axis accelerometer and 3 * IIO driver for the MiraMEMS DA226 2-axis accelerometer 4 * 5 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/i2c.h> 14 #include <linux/iio/iio.h> 15 #include <linux/iio/sysfs.h> 16 #include <linux/byteorder/generic.h> 17 18 #define DA280_REG_CHIP_ID 0x01 19 #define DA280_REG_ACC_X_LSB 0x02 20 #define DA280_REG_ACC_Y_LSB 0x04 21 #define DA280_REG_ACC_Z_LSB 0x06 22 #define DA280_REG_MODE_BW 0x11 23 24 #define DA280_CHIP_ID 0x13 25 #define DA280_MODE_ENABLE 0x1e 26 #define DA280_MODE_DISABLE 0x9e 27 28 enum { da226, da280 }; 29 30 /* 31 * a value of + or -4096 corresponds to + or - 1G 32 * scale = 9.81 / 4096 = 0.002395019 33 */ 34 35 static const int da280_nscale = 2395019; 36 37 #define DA280_CHANNEL(reg, axis) { \ 38 .type = IIO_ACCEL, \ 39 .address = reg, \ 40 .modified = 1, \ 41 .channel2 = IIO_MOD_##axis, \ 42 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 43 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 44 } 45 46 static const struct iio_chan_spec da280_channels[] = { 47 DA280_CHANNEL(DA280_REG_ACC_X_LSB, X), 48 DA280_CHANNEL(DA280_REG_ACC_Y_LSB, Y), 49 DA280_CHANNEL(DA280_REG_ACC_Z_LSB, Z), 50 }; 51 52 struct da280_data { 53 struct i2c_client *client; 54 }; 55 56 static int da280_enable(struct i2c_client *client, bool enable) 57 { 58 u8 data = enable ? DA280_MODE_ENABLE : DA280_MODE_DISABLE; 59 60 return i2c_smbus_write_byte_data(client, DA280_REG_MODE_BW, data); 61 } 62 63 static int da280_read_raw(struct iio_dev *indio_dev, 64 struct iio_chan_spec const *chan, 65 int *val, int *val2, long mask) 66 { 67 struct da280_data *data = iio_priv(indio_dev); 68 int ret; 69 70 switch (mask) { 71 case IIO_CHAN_INFO_RAW: 72 ret = i2c_smbus_read_word_data(data->client, chan->address); 73 if (ret < 0) 74 return ret; 75 /* 76 * Values are 14 bits, stored as 16 bits with the 2 77 * least significant bits always 0. 78 */ 79 *val = (short)ret >> 2; 80 return IIO_VAL_INT; 81 case IIO_CHAN_INFO_SCALE: 82 *val = 0; 83 *val2 = da280_nscale; 84 return IIO_VAL_INT_PLUS_NANO; 85 default: 86 return -EINVAL; 87 } 88 } 89 90 static const struct iio_info da280_info = { 91 .read_raw = da280_read_raw, 92 }; 93 94 static int da280_probe(struct i2c_client *client, 95 const struct i2c_device_id *id) 96 { 97 int ret; 98 struct iio_dev *indio_dev; 99 struct da280_data *data; 100 101 ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID); 102 if (ret != DA280_CHIP_ID) 103 return (ret < 0) ? ret : -ENODEV; 104 105 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 106 if (!indio_dev) 107 return -ENOMEM; 108 109 data = iio_priv(indio_dev); 110 data->client = client; 111 i2c_set_clientdata(client, indio_dev); 112 113 indio_dev->dev.parent = &client->dev; 114 indio_dev->info = &da280_info; 115 indio_dev->modes = INDIO_DIRECT_MODE; 116 indio_dev->channels = da280_channels; 117 if (id->driver_data == da226) { 118 indio_dev->name = "da226"; 119 indio_dev->num_channels = 2; 120 } else { 121 indio_dev->name = "da280"; 122 indio_dev->num_channels = 3; 123 } 124 125 ret = da280_enable(client, true); 126 if (ret < 0) 127 return ret; 128 129 ret = iio_device_register(indio_dev); 130 if (ret < 0) { 131 dev_err(&client->dev, "device_register failed\n"); 132 da280_enable(client, false); 133 } 134 135 return ret; 136 } 137 138 static int da280_remove(struct i2c_client *client) 139 { 140 struct iio_dev *indio_dev = i2c_get_clientdata(client); 141 142 iio_device_unregister(indio_dev); 143 144 return da280_enable(client, false); 145 } 146 147 #ifdef CONFIG_PM_SLEEP 148 static int da280_suspend(struct device *dev) 149 { 150 return da280_enable(to_i2c_client(dev), false); 151 } 152 153 static int da280_resume(struct device *dev) 154 { 155 return da280_enable(to_i2c_client(dev), true); 156 } 157 #endif 158 159 static SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume); 160 161 static const struct i2c_device_id da280_i2c_id[] = { 162 { "da226", da226 }, 163 { "da280", da280 }, 164 {} 165 }; 166 MODULE_DEVICE_TABLE(i2c, da280_i2c_id); 167 168 static struct i2c_driver da280_driver = { 169 .driver = { 170 .name = "da280", 171 .pm = &da280_pm_ops, 172 }, 173 .probe = da280_probe, 174 .remove = da280_remove, 175 .id_table = da280_i2c_id, 176 }; 177 178 module_i2c_driver(da280_driver); 179 180 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 181 MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver"); 182 MODULE_LICENSE("GPL v2"); 183