1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * IIO driver for the MiraMEMS DA280 3-axis accelerometer and 4 * IIO driver for the MiraMEMS DA226 2-axis accelerometer 5 * 6 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com> 7 */ 8 9 #include <linux/module.h> 10 #include <linux/i2c.h> 11 #include <linux/acpi.h> 12 #include <linux/iio/iio.h> 13 #include <linux/iio/sysfs.h> 14 #include <linux/byteorder/generic.h> 15 16 #define DA280_REG_CHIP_ID 0x01 17 #define DA280_REG_ACC_X_LSB 0x02 18 #define DA280_REG_ACC_Y_LSB 0x04 19 #define DA280_REG_ACC_Z_LSB 0x06 20 #define DA280_REG_MODE_BW 0x11 21 22 #define DA280_CHIP_ID 0x13 23 #define DA280_MODE_ENABLE 0x1e 24 #define DA280_MODE_DISABLE 0x9e 25 26 enum da280_chipset { da226, da280 }; 27 28 /* 29 * a value of + or -4096 corresponds to + or - 1G 30 * scale = 9.81 / 4096 = 0.002395019 31 */ 32 33 static const int da280_nscale = 2395019; 34 35 #define DA280_CHANNEL(reg, axis) { \ 36 .type = IIO_ACCEL, \ 37 .address = reg, \ 38 .modified = 1, \ 39 .channel2 = IIO_MOD_##axis, \ 40 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 41 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 42 } 43 44 static const struct iio_chan_spec da280_channels[] = { 45 DA280_CHANNEL(DA280_REG_ACC_X_LSB, X), 46 DA280_CHANNEL(DA280_REG_ACC_Y_LSB, Y), 47 DA280_CHANNEL(DA280_REG_ACC_Z_LSB, Z), 48 }; 49 50 struct da280_data { 51 struct i2c_client *client; 52 }; 53 54 static int da280_enable(struct i2c_client *client, bool enable) 55 { 56 u8 data = enable ? DA280_MODE_ENABLE : DA280_MODE_DISABLE; 57 58 return i2c_smbus_write_byte_data(client, DA280_REG_MODE_BW, data); 59 } 60 61 static int da280_read_raw(struct iio_dev *indio_dev, 62 struct iio_chan_spec const *chan, 63 int *val, int *val2, long mask) 64 { 65 struct da280_data *data = iio_priv(indio_dev); 66 int ret; 67 68 switch (mask) { 69 case IIO_CHAN_INFO_RAW: 70 ret = i2c_smbus_read_word_data(data->client, chan->address); 71 if (ret < 0) 72 return ret; 73 /* 74 * Values are 14 bits, stored as 16 bits with the 2 75 * least significant bits always 0. 76 */ 77 *val = (short)ret >> 2; 78 return IIO_VAL_INT; 79 case IIO_CHAN_INFO_SCALE: 80 *val = 0; 81 *val2 = da280_nscale; 82 return IIO_VAL_INT_PLUS_NANO; 83 default: 84 return -EINVAL; 85 } 86 } 87 88 static const struct iio_info da280_info = { 89 .read_raw = da280_read_raw, 90 }; 91 92 static enum da280_chipset da280_match_acpi_device(struct device *dev) 93 { 94 const struct acpi_device_id *id; 95 96 id = acpi_match_device(dev->driver->acpi_match_table, dev); 97 if (!id) 98 return -EINVAL; 99 100 return (enum da280_chipset) id->driver_data; 101 } 102 103 static void da280_disable(void *client) 104 { 105 da280_enable(client, false); 106 } 107 108 static int da280_probe(struct i2c_client *client, 109 const struct i2c_device_id *id) 110 { 111 int ret; 112 struct iio_dev *indio_dev; 113 struct da280_data *data; 114 enum da280_chipset chip; 115 116 ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID); 117 if (ret != DA280_CHIP_ID) 118 return (ret < 0) ? ret : -ENODEV; 119 120 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 121 if (!indio_dev) 122 return -ENOMEM; 123 124 data = iio_priv(indio_dev); 125 data->client = client; 126 127 indio_dev->info = &da280_info; 128 indio_dev->modes = INDIO_DIRECT_MODE; 129 indio_dev->channels = da280_channels; 130 131 if (ACPI_HANDLE(&client->dev)) { 132 chip = da280_match_acpi_device(&client->dev); 133 } else { 134 chip = id->driver_data; 135 } 136 137 if (chip == da226) { 138 indio_dev->name = "da226"; 139 indio_dev->num_channels = 2; 140 } else { 141 indio_dev->name = "da280"; 142 indio_dev->num_channels = 3; 143 } 144 145 ret = da280_enable(client, true); 146 if (ret < 0) 147 return ret; 148 149 ret = devm_add_action_or_reset(&client->dev, da280_disable, client); 150 if (ret) 151 return ret; 152 153 return devm_iio_device_register(&client->dev, indio_dev); 154 } 155 156 static int da280_suspend(struct device *dev) 157 { 158 return da280_enable(to_i2c_client(dev), false); 159 } 160 161 static int da280_resume(struct device *dev) 162 { 163 return da280_enable(to_i2c_client(dev), true); 164 } 165 166 static DEFINE_SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume); 167 168 static const struct acpi_device_id da280_acpi_match[] = { 169 {"MIRAACC", da280}, 170 {}, 171 }; 172 MODULE_DEVICE_TABLE(acpi, da280_acpi_match); 173 174 static const struct i2c_device_id da280_i2c_id[] = { 175 { "da226", da226 }, 176 { "da280", da280 }, 177 {} 178 }; 179 MODULE_DEVICE_TABLE(i2c, da280_i2c_id); 180 181 static struct i2c_driver da280_driver = { 182 .driver = { 183 .name = "da280", 184 .acpi_match_table = ACPI_PTR(da280_acpi_match), 185 .pm = pm_sleep_ptr(&da280_pm_ops), 186 }, 187 .probe = da280_probe, 188 .id_table = da280_i2c_id, 189 }; 190 191 module_i2c_driver(da280_driver); 192 193 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 194 MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver"); 195 MODULE_LICENSE("GPL v2"); 196