Srinivas Pandruvada | d14c0f1 | 2014-11-06 23:06:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * AK09911 3-axis compass driver |
| 3 | * Copyright (c) 2014, Intel Corporation. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms and conditions of the GNU General Public License, |
| 7 | * version 2, as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * more details. |
| 13 | */ |
| 14 | |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/types.h> |
| 19 | #include <linux/slab.h> |
| 20 | #include <linux/delay.h> |
| 21 | #include <linux/i2c.h> |
| 22 | #include <linux/acpi.h> |
| 23 | #include <linux/iio/iio.h> |
| 24 | |
| 25 | #define AK09911_REG_WIA1 0x00 |
| 26 | #define AK09911_REG_WIA2 0x01 |
| 27 | #define AK09911_WIA1_VALUE 0x48 |
| 28 | #define AK09911_WIA2_VALUE 0x05 |
| 29 | |
| 30 | #define AK09911_REG_ST1 0x10 |
| 31 | #define AK09911_REG_HXL 0x11 |
| 32 | #define AK09911_REG_HXH 0x12 |
| 33 | #define AK09911_REG_HYL 0x13 |
| 34 | #define AK09911_REG_HYH 0x14 |
| 35 | #define AK09911_REG_HZL 0x15 |
| 36 | #define AK09911_REG_HZH 0x16 |
| 37 | |
| 38 | #define AK09911_REG_ASAX 0x60 |
| 39 | #define AK09911_REG_ASAY 0x61 |
| 40 | #define AK09911_REG_ASAZ 0x62 |
| 41 | |
| 42 | #define AK09911_REG_CNTL1 0x30 |
| 43 | #define AK09911_REG_CNTL2 0x31 |
| 44 | #define AK09911_REG_CNTL3 0x32 |
| 45 | |
| 46 | #define AK09911_MODE_SNG_MEASURE 0x01 |
| 47 | #define AK09911_MODE_SELF_TEST 0x10 |
| 48 | #define AK09911_MODE_FUSE_ACCESS 0x1F |
| 49 | #define AK09911_MODE_POWERDOWN 0x00 |
| 50 | #define AK09911_RESET_DATA 0x01 |
| 51 | |
| 52 | #define AK09911_REG_CNTL1 0x30 |
| 53 | #define AK09911_REG_CNTL2 0x31 |
| 54 | #define AK09911_REG_CNTL3 0x32 |
| 55 | |
| 56 | #define AK09911_RAW_TO_GAUSS(asa) ((((asa) + 128) * 6000) / 256) |
| 57 | |
| 58 | #define AK09911_MAX_CONVERSION_TIMEOUT_MS 500 |
| 59 | #define AK09911_CONVERSION_DONE_POLL_TIME_MS 10 |
| 60 | |
| 61 | struct ak09911_data { |
| 62 | struct i2c_client *client; |
| 63 | struct mutex lock; |
| 64 | u8 asa[3]; |
| 65 | long raw_to_gauss[3]; |
| 66 | }; |
| 67 | |
| 68 | static const int ak09911_index_to_reg[] = { |
| 69 | AK09911_REG_HXL, AK09911_REG_HYL, AK09911_REG_HZL, |
| 70 | }; |
| 71 | |
| 72 | static int ak09911_set_mode(struct i2c_client *client, u8 mode) |
| 73 | { |
| 74 | int ret; |
| 75 | |
| 76 | switch (mode) { |
| 77 | case AK09911_MODE_SNG_MEASURE: |
| 78 | case AK09911_MODE_SELF_TEST: |
| 79 | case AK09911_MODE_FUSE_ACCESS: |
| 80 | case AK09911_MODE_POWERDOWN: |
| 81 | ret = i2c_smbus_write_byte_data(client, |
| 82 | AK09911_REG_CNTL2, mode); |
| 83 | if (ret < 0) { |
| 84 | dev_err(&client->dev, "set_mode error\n"); |
| 85 | return ret; |
| 86 | } |
| 87 | /* After mode change wait atleast 100us */ |
| 88 | usleep_range(100, 500); |
| 89 | break; |
| 90 | default: |
| 91 | dev_err(&client->dev, |
| 92 | "%s: Unknown mode(%d).", __func__, mode); |
| 93 | return -EINVAL; |
| 94 | } |
| 95 | |
| 96 | return ret; |
| 97 | } |
| 98 | |
| 99 | /* Get Sensitivity Adjustment value */ |
| 100 | static int ak09911_get_asa(struct i2c_client *client) |
| 101 | { |
| 102 | struct iio_dev *indio_dev = i2c_get_clientdata(client); |
| 103 | struct ak09911_data *data = iio_priv(indio_dev); |
| 104 | int ret; |
| 105 | |
| 106 | ret = ak09911_set_mode(client, AK09911_MODE_FUSE_ACCESS); |
| 107 | if (ret < 0) |
| 108 | return ret; |
| 109 | |
| 110 | /* Get asa data and store in the device data. */ |
| 111 | ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_ASAX, |
| 112 | 3, data->asa); |
| 113 | if (ret < 0) { |
| 114 | dev_err(&client->dev, "Not able to read asa data\n"); |
| 115 | return ret; |
| 116 | } |
| 117 | |
| 118 | ret = ak09911_set_mode(client, AK09911_MODE_POWERDOWN); |
| 119 | if (ret < 0) |
| 120 | return ret; |
| 121 | |
| 122 | data->raw_to_gauss[0] = AK09911_RAW_TO_GAUSS(data->asa[0]); |
| 123 | data->raw_to_gauss[1] = AK09911_RAW_TO_GAUSS(data->asa[1]); |
| 124 | data->raw_to_gauss[2] = AK09911_RAW_TO_GAUSS(data->asa[2]); |
| 125 | |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | static int ak09911_verify_chip_id(struct i2c_client *client) |
| 130 | { |
| 131 | u8 wia_val[2]; |
| 132 | int ret; |
| 133 | |
| 134 | ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_WIA1, |
| 135 | 2, wia_val); |
| 136 | if (ret < 0) { |
| 137 | dev_err(&client->dev, "Error reading WIA\n"); |
| 138 | return ret; |
| 139 | } |
| 140 | |
| 141 | dev_dbg(&client->dev, "WIA %02x %02x\n", wia_val[0], wia_val[1]); |
| 142 | |
| 143 | if (wia_val[0] != AK09911_WIA1_VALUE || |
| 144 | wia_val[1] != AK09911_WIA2_VALUE) { |
| 145 | dev_err(&client->dev, "Device ak09911 not found\n"); |
| 146 | return -ENODEV; |
| 147 | } |
| 148 | |
| 149 | return 0; |
| 150 | } |
| 151 | |
| 152 | static int wait_conversion_complete_polled(struct ak09911_data *data) |
| 153 | { |
| 154 | struct i2c_client *client = data->client; |
| 155 | u8 read_status; |
| 156 | u32 timeout_ms = AK09911_MAX_CONVERSION_TIMEOUT_MS; |
| 157 | int ret; |
| 158 | |
| 159 | /* Wait for the conversion to complete. */ |
| 160 | while (timeout_ms) { |
| 161 | msleep_interruptible(AK09911_CONVERSION_DONE_POLL_TIME_MS); |
| 162 | ret = i2c_smbus_read_byte_data(client, AK09911_REG_ST1); |
| 163 | if (ret < 0) { |
| 164 | dev_err(&client->dev, "Error in reading ST1\n"); |
| 165 | return ret; |
| 166 | } |
| 167 | read_status = ret & 0x01; |
| 168 | if (read_status) |
| 169 | break; |
| 170 | timeout_ms -= AK09911_CONVERSION_DONE_POLL_TIME_MS; |
| 171 | } |
| 172 | if (!timeout_ms) { |
| 173 | dev_err(&client->dev, "Conversion timeout happened\n"); |
| 174 | return -EIO; |
| 175 | } |
| 176 | |
| 177 | return read_status; |
| 178 | } |
| 179 | |
| 180 | static int ak09911_read_axis(struct iio_dev *indio_dev, int index, int *val) |
| 181 | { |
| 182 | struct ak09911_data *data = iio_priv(indio_dev); |
| 183 | struct i2c_client *client = data->client; |
| 184 | int ret; |
| 185 | |
| 186 | mutex_lock(&data->lock); |
| 187 | |
| 188 | ret = ak09911_set_mode(client, AK09911_MODE_SNG_MEASURE); |
| 189 | if (ret < 0) |
| 190 | goto fn_exit; |
| 191 | |
| 192 | ret = wait_conversion_complete_polled(data); |
| 193 | if (ret < 0) |
| 194 | goto fn_exit; |
| 195 | |
| 196 | /* Read data */ |
| 197 | ret = i2c_smbus_read_word_data(client, ak09911_index_to_reg[index]); |
| 198 | if (ret < 0) { |
| 199 | dev_err(&client->dev, "Read axis data fails\n"); |
| 200 | goto fn_exit; |
| 201 | } |
| 202 | |
| 203 | mutex_unlock(&data->lock); |
| 204 | |
| 205 | /* Clamp to valid range. */ |
| 206 | *val = sign_extend32(clamp_t(s16, ret, -8192, 8191), 13); |
| 207 | |
| 208 | return IIO_VAL_INT; |
| 209 | |
| 210 | fn_exit: |
| 211 | mutex_unlock(&data->lock); |
| 212 | |
| 213 | return ret; |
| 214 | } |
| 215 | |
| 216 | static int ak09911_read_raw(struct iio_dev *indio_dev, |
| 217 | struct iio_chan_spec const *chan, |
| 218 | int *val, int *val2, |
| 219 | long mask) |
| 220 | { |
| 221 | struct ak09911_data *data = iio_priv(indio_dev); |
| 222 | |
| 223 | switch (mask) { |
| 224 | case IIO_CHAN_INFO_RAW: |
| 225 | return ak09911_read_axis(indio_dev, chan->address, val); |
| 226 | case IIO_CHAN_INFO_SCALE: |
| 227 | *val = 0; |
| 228 | *val2 = data->raw_to_gauss[chan->address]; |
| 229 | return IIO_VAL_INT_PLUS_MICRO; |
| 230 | } |
| 231 | |
| 232 | return -EINVAL; |
| 233 | } |
| 234 | |
| 235 | #define AK09911_CHANNEL(axis, index) \ |
| 236 | { \ |
| 237 | .type = IIO_MAGN, \ |
| 238 | .modified = 1, \ |
| 239 | .channel2 = IIO_MOD_##axis, \ |
| 240 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ |
| 241 | BIT(IIO_CHAN_INFO_SCALE), \ |
| 242 | .address = index, \ |
| 243 | } |
| 244 | |
| 245 | static const struct iio_chan_spec ak09911_channels[] = { |
| 246 | AK09911_CHANNEL(X, 0), AK09911_CHANNEL(Y, 1), AK09911_CHANNEL(Z, 2), |
| 247 | }; |
| 248 | |
| 249 | static const struct iio_info ak09911_info = { |
| 250 | .read_raw = &ak09911_read_raw, |
| 251 | .driver_module = THIS_MODULE, |
| 252 | }; |
| 253 | |
| 254 | static const struct acpi_device_id ak_acpi_match[] = { |
| 255 | {"AK009911", 0}, |
| 256 | { }, |
| 257 | }; |
| 258 | MODULE_DEVICE_TABLE(acpi, ak_acpi_match); |
| 259 | |
| 260 | static int ak09911_probe(struct i2c_client *client, |
| 261 | const struct i2c_device_id *id) |
| 262 | { |
| 263 | struct iio_dev *indio_dev; |
| 264 | struct ak09911_data *data; |
| 265 | const char *name; |
| 266 | int ret; |
| 267 | |
| 268 | ret = ak09911_verify_chip_id(client); |
| 269 | if (ret) { |
| 270 | dev_err(&client->dev, "AK00911 not detected\n"); |
| 271 | return -ENODEV; |
| 272 | } |
| 273 | |
| 274 | indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| 275 | if (indio_dev == NULL) |
| 276 | return -ENOMEM; |
| 277 | |
| 278 | data = iio_priv(indio_dev); |
| 279 | i2c_set_clientdata(client, indio_dev); |
| 280 | |
| 281 | data->client = client; |
| 282 | mutex_init(&data->lock); |
| 283 | |
| 284 | ret = ak09911_get_asa(client); |
| 285 | if (ret) |
| 286 | return ret; |
| 287 | |
| 288 | if (id) |
| 289 | name = id->name; |
| 290 | else if (ACPI_HANDLE(&client->dev)) |
| 291 | name = dev_name(&client->dev); |
| 292 | else |
| 293 | return -ENODEV; |
| 294 | |
| 295 | dev_dbg(&client->dev, "Asahi compass chip %s\n", name); |
| 296 | |
| 297 | indio_dev->dev.parent = &client->dev; |
| 298 | indio_dev->channels = ak09911_channels; |
| 299 | indio_dev->num_channels = ARRAY_SIZE(ak09911_channels); |
| 300 | indio_dev->info = &ak09911_info; |
| 301 | indio_dev->modes = INDIO_DIRECT_MODE; |
| 302 | indio_dev->name = name; |
| 303 | |
| 304 | return devm_iio_device_register(&client->dev, indio_dev); |
| 305 | } |
| 306 | |
| 307 | static const struct i2c_device_id ak09911_id[] = { |
| 308 | {"ak09911", 0}, |
| 309 | {} |
| 310 | }; |
| 311 | |
| 312 | MODULE_DEVICE_TABLE(i2c, ak09911_id); |
| 313 | |
| 314 | static struct i2c_driver ak09911_driver = { |
| 315 | .driver = { |
| 316 | .name = "ak09911", |
| 317 | .acpi_match_table = ACPI_PTR(ak_acpi_match), |
| 318 | }, |
| 319 | .probe = ak09911_probe, |
| 320 | .id_table = ak09911_id, |
| 321 | }; |
| 322 | module_i2c_driver(ak09911_driver); |
| 323 | |
| 324 | MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>"); |
| 325 | MODULE_LICENSE("GPL v2"); |
| 326 | MODULE_DESCRIPTION("AK09911 Compass driver"); |