1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Freescale MMA7660FC 3-Axis Accelerometer 4 * 5 * Copyright (c) 2016, Intel Corporation. 6 * 7 * IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c. 8 */ 9 10 #include <linux/i2c.h> 11 #include <linux/mod_devicetable.h> 12 #include <linux/module.h> 13 #include <linux/iio/iio.h> 14 #include <linux/iio/sysfs.h> 15 16 #define MMA7660_DRIVER_NAME "mma7660" 17 18 #define MMA7660_REG_XOUT 0x00 19 #define MMA7660_REG_YOUT 0x01 20 #define MMA7660_REG_ZOUT 0x02 21 #define MMA7660_REG_OUT_BIT_ALERT BIT(6) 22 23 #define MMA7660_REG_MODE 0x07 24 #define MMA7660_REG_MODE_BIT_MODE BIT(0) 25 #define MMA7660_REG_MODE_BIT_TON BIT(2) 26 27 #define MMA7660_I2C_READ_RETRIES 5 28 29 /* 30 * The accelerometer has one measurement range: 31 * 32 * -1.5g - +1.5g (6-bit, signed) 33 * 34 * scale = (1.5 + 1.5) * 9.81 / (2^6 - 1) = 0.467142857 35 */ 36 37 #define MMA7660_SCALE_AVAIL "0.467142857" 38 39 static const int mma7660_nscale = 467142857; 40 41 #define MMA7660_CHANNEL(reg, axis) { \ 42 .type = IIO_ACCEL, \ 43 .address = reg, \ 44 .modified = 1, \ 45 .channel2 = IIO_MOD_##axis, \ 46 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 47 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 48 } 49 50 static const struct iio_chan_spec mma7660_channels[] = { 51 MMA7660_CHANNEL(MMA7660_REG_XOUT, X), 52 MMA7660_CHANNEL(MMA7660_REG_YOUT, Y), 53 MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z), 54 }; 55 56 enum mma7660_mode { 57 MMA7660_MODE_STANDBY, 58 MMA7660_MODE_ACTIVE 59 }; 60 61 struct mma7660_data { 62 struct i2c_client *client; 63 struct mutex lock; 64 enum mma7660_mode mode; 65 }; 66 67 static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL); 68 69 static struct attribute *mma7660_attributes[] = { 70 &iio_const_attr_in_accel_scale_available.dev_attr.attr, 71 NULL, 72 }; 73 74 static const struct attribute_group mma7660_attribute_group = { 75 .attrs = mma7660_attributes 76 }; 77 78 static int mma7660_set_mode(struct mma7660_data *data, 79 enum mma7660_mode mode) 80 { 81 int ret; 82 struct i2c_client *client = data->client; 83 84 if (mode == data->mode) 85 return 0; 86 87 ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE); 88 if (ret < 0) { 89 dev_err(&client->dev, "failed to read sensor mode\n"); 90 return ret; 91 } 92 93 if (mode == MMA7660_MODE_ACTIVE) { 94 ret &= ~MMA7660_REG_MODE_BIT_TON; 95 ret |= MMA7660_REG_MODE_BIT_MODE; 96 } else { 97 ret &= ~MMA7660_REG_MODE_BIT_TON; 98 ret &= ~MMA7660_REG_MODE_BIT_MODE; 99 } 100 101 ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret); 102 if (ret < 0) { 103 dev_err(&client->dev, "failed to change sensor mode\n"); 104 return ret; 105 } 106 107 data->mode = mode; 108 109 return ret; 110 } 111 112 static int mma7660_read_accel(struct mma7660_data *data, u8 address) 113 { 114 int ret, retries = MMA7660_I2C_READ_RETRIES; 115 struct i2c_client *client = data->client; 116 117 /* 118 * Read data. If the Alert bit is set, the register was read at 119 * the same time as the device was attempting to update the content. 120 * The solution is to read the register again. Do this only 121 * MMA7660_I2C_READ_RETRIES times to avoid spending too much time 122 * in the kernel. 123 */ 124 do { 125 ret = i2c_smbus_read_byte_data(client, address); 126 if (ret < 0) { 127 dev_err(&client->dev, "register read failed\n"); 128 return ret; 129 } 130 } while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT); 131 132 if (ret & MMA7660_REG_OUT_BIT_ALERT) { 133 dev_err(&client->dev, "all register read retries failed\n"); 134 return -ETIMEDOUT; 135 } 136 137 return ret; 138 } 139 140 static int mma7660_read_raw(struct iio_dev *indio_dev, 141 struct iio_chan_spec const *chan, 142 int *val, int *val2, long mask) 143 { 144 struct mma7660_data *data = iio_priv(indio_dev); 145 int ret; 146 147 switch (mask) { 148 case IIO_CHAN_INFO_RAW: 149 mutex_lock(&data->lock); 150 ret = mma7660_read_accel(data, chan->address); 151 mutex_unlock(&data->lock); 152 if (ret < 0) 153 return ret; 154 *val = sign_extend32(ret, 5); 155 return IIO_VAL_INT; 156 case IIO_CHAN_INFO_SCALE: 157 *val = 0; 158 *val2 = mma7660_nscale; 159 return IIO_VAL_INT_PLUS_NANO; 160 default: 161 return -EINVAL; 162 } 163 164 return -EINVAL; 165 } 166 167 static const struct iio_info mma7660_info = { 168 .read_raw = mma7660_read_raw, 169 .attrs = &mma7660_attribute_group, 170 }; 171 172 static int mma7660_probe(struct i2c_client *client, 173 const struct i2c_device_id *id) 174 { 175 int ret; 176 struct iio_dev *indio_dev; 177 struct mma7660_data *data; 178 179 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 180 if (!indio_dev) { 181 dev_err(&client->dev, "iio allocation failed!\n"); 182 return -ENOMEM; 183 } 184 185 data = iio_priv(indio_dev); 186 data->client = client; 187 i2c_set_clientdata(client, indio_dev); 188 mutex_init(&data->lock); 189 data->mode = MMA7660_MODE_STANDBY; 190 191 indio_dev->info = &mma7660_info; 192 indio_dev->name = MMA7660_DRIVER_NAME; 193 indio_dev->modes = INDIO_DIRECT_MODE; 194 indio_dev->channels = mma7660_channels; 195 indio_dev->num_channels = ARRAY_SIZE(mma7660_channels); 196 197 ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE); 198 if (ret < 0) 199 return ret; 200 201 ret = iio_device_register(indio_dev); 202 if (ret < 0) { 203 dev_err(&client->dev, "device_register failed\n"); 204 mma7660_set_mode(data, MMA7660_MODE_STANDBY); 205 } 206 207 return ret; 208 } 209 210 static int mma7660_remove(struct i2c_client *client) 211 { 212 struct iio_dev *indio_dev = i2c_get_clientdata(client); 213 int ret; 214 215 iio_device_unregister(indio_dev); 216 217 ret = mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY); 218 if (ret) 219 dev_warn(&client->dev, "Failed to put device in stand-by mode (%pe), ignoring\n", 220 ERR_PTR(ret)); 221 222 return 0; 223 } 224 225 static int mma7660_suspend(struct device *dev) 226 { 227 struct mma7660_data *data; 228 229 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 230 231 return mma7660_set_mode(data, MMA7660_MODE_STANDBY); 232 } 233 234 static int mma7660_resume(struct device *dev) 235 { 236 struct mma7660_data *data; 237 238 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); 239 240 return mma7660_set_mode(data, MMA7660_MODE_ACTIVE); 241 } 242 243 static DEFINE_SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, 244 mma7660_resume); 245 246 static const struct i2c_device_id mma7660_i2c_id[] = { 247 {"mma7660", 0}, 248 {} 249 }; 250 MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id); 251 252 static const struct of_device_id mma7660_of_match[] = { 253 { .compatible = "fsl,mma7660" }, 254 { } 255 }; 256 MODULE_DEVICE_TABLE(of, mma7660_of_match); 257 258 static const struct acpi_device_id mma7660_acpi_id[] = { 259 {"MMA7660", 0}, 260 {} 261 }; 262 263 MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id); 264 265 static struct i2c_driver mma7660_driver = { 266 .driver = { 267 .name = "mma7660", 268 .pm = pm_sleep_ptr(&mma7660_pm_ops), 269 .of_match_table = mma7660_of_match, 270 .acpi_match_table = mma7660_acpi_id, 271 }, 272 .probe = mma7660_probe, 273 .remove = mma7660_remove, 274 .id_table = mma7660_i2c_id, 275 }; 276 277 module_i2c_driver(mma7660_driver); 278 279 MODULE_AUTHOR("Constantin Musca <constantin.musca@intel.com>"); 280 MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver"); 281 MODULE_LICENSE("GPL v2"); 282