1 /** 2 * mCube MC3230 3-Axis Accelerometer 3 * 4 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * IIO driver for mCube MC3230; 7-bit I2C address: 0x4c. 12 */ 13 14 #include <linux/i2c.h> 15 #include <linux/module.h> 16 #include <linux/iio/iio.h> 17 #include <linux/iio/sysfs.h> 18 19 #define MC3230_REG_XOUT 0x00 20 #define MC3230_REG_YOUT 0x01 21 #define MC3230_REG_ZOUT 0x02 22 23 #define MC3230_REG_MODE 0x07 24 #define MC3230_MODE_OPCON_MASK 0x03 25 #define MC3230_MODE_OPCON_WAKE 0x01 26 #define MC3230_MODE_OPCON_STANDBY 0x03 27 28 #define MC3230_REG_CHIP_ID 0x18 29 #define MC3230_CHIP_ID 0x01 30 31 #define MC3230_REG_PRODUCT_CODE 0x3b 32 #define MC3230_PRODUCT_CODE 0x19 33 34 /* 35 * The accelerometer has one measurement range: 36 * 37 * -1.5g - +1.5g (8-bit, signed) 38 * 39 * scale = (1.5 + 1.5) * 9.81 / (2^8 - 1) = 0.115411765 40 */ 41 42 static const int mc3230_nscale = 115411765; 43 44 #define MC3230_CHANNEL(reg, axis) { \ 45 .type = IIO_ACCEL, \ 46 .address = reg, \ 47 .modified = 1, \ 48 .channel2 = IIO_MOD_##axis, \ 49 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 50 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 51 } 52 53 static const struct iio_chan_spec mc3230_channels[] = { 54 MC3230_CHANNEL(MC3230_REG_XOUT, X), 55 MC3230_CHANNEL(MC3230_REG_YOUT, Y), 56 MC3230_CHANNEL(MC3230_REG_ZOUT, Z), 57 }; 58 59 struct mc3230_data { 60 struct i2c_client *client; 61 }; 62 63 static int mc3230_set_opcon(struct mc3230_data *data, int opcon) 64 { 65 int ret; 66 struct i2c_client *client = data->client; 67 68 ret = i2c_smbus_read_byte_data(client, MC3230_REG_MODE); 69 if (ret < 0) { 70 dev_err(&client->dev, "failed to read mode reg: %d\n", ret); 71 return ret; 72 } 73 74 ret &= ~MC3230_MODE_OPCON_MASK; 75 ret |= opcon; 76 77 ret = i2c_smbus_write_byte_data(client, MC3230_REG_MODE, ret); 78 if (ret < 0) { 79 dev_err(&client->dev, "failed to write mode reg: %d\n", ret); 80 return ret; 81 } 82 83 return 0; 84 } 85 86 static int mc3230_read_raw(struct iio_dev *indio_dev, 87 struct iio_chan_spec const *chan, 88 int *val, int *val2, long mask) 89 { 90 struct mc3230_data *data = iio_priv(indio_dev); 91 int ret; 92 93 switch (mask) { 94 case IIO_CHAN_INFO_RAW: 95 ret = i2c_smbus_read_byte_data(data->client, chan->address); 96 if (ret < 0) 97 return ret; 98 *val = sign_extend32(ret, 7); 99 return IIO_VAL_INT; 100 case IIO_CHAN_INFO_SCALE: 101 *val = 0; 102 *val2 = mc3230_nscale; 103 return IIO_VAL_INT_PLUS_NANO; 104 default: 105 return -EINVAL; 106 } 107 } 108 109 static const struct iio_info mc3230_info = { 110 .read_raw = mc3230_read_raw, 111 }; 112 113 static int mc3230_probe(struct i2c_client *client, 114 const struct i2c_device_id *id) 115 { 116 int ret; 117 struct iio_dev *indio_dev; 118 struct mc3230_data *data; 119 120 /* First check chip-id and product-id */ 121 ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID); 122 if (ret != MC3230_CHIP_ID) 123 return (ret < 0) ? ret : -ENODEV; 124 125 ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE); 126 if (ret != MC3230_PRODUCT_CODE) 127 return (ret < 0) ? ret : -ENODEV; 128 129 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 130 if (!indio_dev) { 131 dev_err(&client->dev, "iio allocation failed!\n"); 132 return -ENOMEM; 133 } 134 135 data = iio_priv(indio_dev); 136 data->client = client; 137 i2c_set_clientdata(client, indio_dev); 138 139 indio_dev->dev.parent = &client->dev; 140 indio_dev->info = &mc3230_info; 141 indio_dev->name = "mc3230"; 142 indio_dev->modes = INDIO_DIRECT_MODE; 143 indio_dev->channels = mc3230_channels; 144 indio_dev->num_channels = ARRAY_SIZE(mc3230_channels); 145 146 ret = mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE); 147 if (ret < 0) 148 return ret; 149 150 ret = iio_device_register(indio_dev); 151 if (ret < 0) { 152 dev_err(&client->dev, "device_register failed\n"); 153 mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY); 154 } 155 156 return ret; 157 } 158 159 static int mc3230_remove(struct i2c_client *client) 160 { 161 struct iio_dev *indio_dev = i2c_get_clientdata(client); 162 163 iio_device_unregister(indio_dev); 164 165 return mc3230_set_opcon(iio_priv(indio_dev), MC3230_MODE_OPCON_STANDBY); 166 } 167 168 #ifdef CONFIG_PM_SLEEP 169 static int mc3230_suspend(struct device *dev) 170 { 171 struct mc3230_data *data; 172 173 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 174 175 return mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY); 176 } 177 178 static int mc3230_resume(struct device *dev) 179 { 180 struct mc3230_data *data; 181 182 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 183 184 return mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE); 185 } 186 #endif 187 188 static SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume); 189 190 static const struct i2c_device_id mc3230_i2c_id[] = { 191 {"mc3230", 0}, 192 {} 193 }; 194 MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id); 195 196 static struct i2c_driver mc3230_driver = { 197 .driver = { 198 .name = "mc3230", 199 .pm = &mc3230_pm_ops, 200 }, 201 .probe = mc3230_probe, 202 .remove = mc3230_remove, 203 .id_table = mc3230_i2c_id, 204 }; 205 206 module_i2c_driver(mc3230_driver); 207 208 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 209 MODULE_DESCRIPTION("mCube MC3230 3-Axis Accelerometer driver"); 210 MODULE_LICENSE("GPL v2"); 211