--- /dev/null
+/*
+ * 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");
projects / users / hch / uuid.git / commitdiff