diff options
Diffstat (limited to 'drivers/iio/magnetometer/ak09911.c')
| -rw-r--r-- | drivers/iio/magnetometer/ak09911.c | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/drivers/iio/magnetometer/ak09911.c b/drivers/iio/magnetometer/ak09911.c new file mode 100644 index 00000000000..b2bc942ff6b --- /dev/null +++ b/drivers/iio/magnetometer/ak09911.c @@ -0,0 +1,326 @@ +/* + * AK09911 3-axis compass driver + * Copyright (c) 2014, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/acpi.h> +#include <linux/iio/iio.h> + +#define AK09911_REG_WIA1 0x00 +#define AK09911_REG_WIA2 0x01 +#define AK09911_WIA1_VALUE 0x48 +#define AK09911_WIA2_VALUE 0x05 + +#define AK09911_REG_ST1 0x10 +#define AK09911_REG_HXL 0x11 +#define AK09911_REG_HXH 0x12 +#define AK09911_REG_HYL 0x13 +#define AK09911_REG_HYH 0x14 +#define AK09911_REG_HZL 0x15 +#define AK09911_REG_HZH 0x16 + +#define AK09911_REG_ASAX 0x60 +#define AK09911_REG_ASAY 0x61 +#define AK09911_REG_ASAZ 0x62 + +#define AK09911_REG_CNTL1 0x30 +#define AK09911_REG_CNTL2 0x31 +#define AK09911_REG_CNTL3 0x32 + +#define AK09911_MODE_SNG_MEASURE 0x01 +#define AK09911_MODE_SELF_TEST 0x10 +#define AK09911_MODE_FUSE_ACCESS 0x1F +#define AK09911_MODE_POWERDOWN 0x00 +#define AK09911_RESET_DATA 0x01 + +#define AK09911_REG_CNTL1 0x30 +#define AK09911_REG_CNTL2 0x31 +#define AK09911_REG_CNTL3 0x32 + +#define AK09911_RAW_TO_GAUSS(asa) ((((asa) + 128) * 6000) / 256) + +#define AK09911_MAX_CONVERSION_TIMEOUT_MS 500 +#define AK09911_CONVERSION_DONE_POLL_TIME_MS 10 + +struct ak09911_data { + struct i2c_client *client; + struct mutex lock; + u8 asa[3]; + long raw_to_gauss[3]; +}; + +static const int ak09911_index_to_reg[] = { + AK09911_REG_HXL, AK09911_REG_HYL, AK09911_REG_HZL, +}; + +static int ak09911_set_mode(struct i2c_client *client, u8 mode) +{ + int ret; + + switch (mode) { + case AK09911_MODE_SNG_MEASURE: + case AK09911_MODE_SELF_TEST: + case AK09911_MODE_FUSE_ACCESS: + case AK09911_MODE_POWERDOWN: + ret = i2c_smbus_write_byte_data(client, + AK09911_REG_CNTL2, mode); + if (ret < 0) { + dev_err(&client->dev, "set_mode error\n"); + return ret; + } + /* After mode change wait atleast 100us */ + usleep_range(100, 500); + break; + default: + dev_err(&client->dev, + "%s: Unknown mode(%d).", __func__, mode); + return -EINVAL; + } + + return ret; +} + +/* Get Sensitivity Adjustment value */ +static int ak09911_get_asa(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + struct ak09911_data *data = iio_priv(indio_dev); + int ret; + + ret = ak09911_set_mode(client, AK09911_MODE_FUSE_ACCESS); + if (ret < 0) + return ret; + + /* Get asa data and store in the device data. */ + ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_ASAX, + 3, data->asa); + if (ret < 0) { + dev_err(&client->dev, "Not able to read asa data\n"); + return ret; + } + + ret = ak09911_set_mode(client, AK09911_MODE_POWERDOWN); + if (ret < 0) + return ret; + + data->raw_to_gauss[0] = AK09911_RAW_TO_GAUSS(data->asa[0]); + data->raw_to_gauss[1] = AK09911_RAW_TO_GAUSS(data->asa[1]); + data->raw_to_gauss[2] = AK09911_RAW_TO_GAUSS(data->asa[2]); + + return 0; +} + +static int ak09911_verify_chip_id(struct i2c_client *client) +{ + u8 wia_val[2]; + int ret; + + ret = i2c_smbus_read_i2c_block_data(client, AK09911_REG_WIA1, + 2, wia_val); + if (ret < 0) { + dev_err(&client->dev, "Error reading WIA\n"); + return ret; + } + + dev_dbg(&client->dev, "WIA %02x %02x\n", wia_val[0], wia_val[1]); + + if (wia_val[0] != AK09911_WIA1_VALUE || + wia_val[1] != AK09911_WIA2_VALUE) { + dev_err(&client->dev, "Device ak09911 not found\n"); + return -ENODEV; + } + + return 0; +} + +static int wait_conversion_complete_polled(struct ak09911_data *data) +{ + struct i2c_client *client = data->client; + u8 read_status; + u32 timeout_ms = AK09911_MAX_CONVERSION_TIMEOUT_MS; + int ret; + + /* Wait for the conversion to complete. */ + while (timeout_ms) { + msleep_interruptible(AK09911_CONVERSION_DONE_POLL_TIME_MS); + ret = i2c_smbus_read_byte_data(client, AK09911_REG_ST1); + if (ret < 0) { + dev_err(&client->dev, "Error in reading ST1\n"); + return ret; + } + read_status = ret & 0x01; + if (read_status) + break; + timeout_ms -= AK09911_CONVERSION_DONE_POLL_TIME_MS; + } + if (!timeout_ms) { + dev_err(&client->dev, "Conversion timeout happened\n"); + return -EIO; + } + + return read_status; +} + +static int ak09911_read_axis(struct iio_dev *indio_dev, int index, int *val) +{ + struct ak09911_data *data = iio_priv(indio_dev); + struct i2c_client *client = data->client; + int ret; + + mutex_lock(&data->lock); + + ret = ak09911_set_mode(client, AK09911_MODE_SNG_MEASURE); + if (ret < 0) + goto fn_exit; + + ret = wait_conversion_complete_polled(data); + if (ret < 0) + goto fn_exit; + + /* Read data */ + ret = i2c_smbus_read_word_data(client, ak09911_index_to_reg[index]); + if (ret < 0) { + dev_err(&client->dev, "Read axis data fails\n"); + goto fn_exit; + } + + mutex_unlock(&data->lock); + + /* Clamp to valid range. */ + *val = sign_extend32(clamp_t(s16, ret, -8192, 8191), 13); + + return IIO_VAL_INT; + +fn_exit: + mutex_unlock(&data->lock); + + return ret; +} + +static int ak09911_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, + long mask) +{ + struct ak09911_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return ak09911_read_axis(indio_dev, chan->address, val); + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = data->raw_to_gauss[chan->address]; + return IIO_VAL_INT_PLUS_MICRO; + } + + return -EINVAL; +} + +#define AK09911_CHANNEL(axis, index) \ + { \ + .type = IIO_MAGN, \ + .modified = 1, \ + .channel2 = IIO_MOD_##axis, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ + BIT(IIO_CHAN_INFO_SCALE), \ + .address = index, \ + } + +static const struct iio_chan_spec ak09911_channels[] = { + AK09911_CHANNEL(X, 0), AK09911_CHANNEL(Y, 1), AK09911_CHANNEL(Z, 2), +}; + +static const struct iio_info ak09911_info = { + .read_raw = &ak09911_read_raw, + .driver_module = THIS_MODULE, +}; + +static const struct acpi_device_id ak_acpi_match[] = { + {"AK009911", 0}, + { }, +}; +MODULE_DEVICE_TABLE(acpi, ak_acpi_match); + +static int ak09911_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct iio_dev *indio_dev; + struct ak09911_data *data; + const char *name; + int ret; + + ret = ak09911_verify_chip_id(client); + if (ret) { + dev_err(&client->dev, "AK00911 not detected\n"); + return -ENODEV; + } + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (indio_dev == NULL) + return -ENOMEM; + + data = iio_priv(indio_dev); + i2c_set_clientdata(client, indio_dev); + + data->client = client; + mutex_init(&data->lock); + + ret = ak09911_get_asa(client); + if (ret) + return ret; + + if (id) + name = id->name; + else if (ACPI_HANDLE(&client->dev)) + name = dev_name(&client->dev); + else + return -ENODEV; + + dev_dbg(&client->dev, "Asahi compass chip %s\n", name); + + indio_dev->dev.parent = &client->dev; + indio_dev->channels = ak09911_channels; + indio_dev->num_channels = ARRAY_SIZE(ak09911_channels); + indio_dev->info = &ak09911_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->name = name; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct i2c_device_id ak09911_id[] = { + {"ak09911", 0}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, ak09911_id); + +static struct i2c_driver ak09911_driver = { + .driver = { + .name = "ak09911", + .acpi_match_table = ACPI_PTR(ak_acpi_match), + }, + .probe = ak09911_probe, + .id_table = ak09911_id, +}; +module_i2c_driver(ak09911_driver); + +MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("AK09911 Compass driver"); |