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- /*
- * 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");
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