> Added IIO magnetometer driver for AK09911. In functionality is resembles
> AK8975 or AK8963. But there are several differences, so instead of
> modifying existing AK8975 driver and keep it clean, implemented as
> a separate driver.
> The key differences are:
> - Register map is different and have different indexes
> - AK09911 is a very compact interface with no DRDY pin. So no support
> of interrupt of GPIO poll
or GPIO poll?
> - Even for polled mode no mention on ST2 register, which is required in
> ak8975 driver
> - mode values are different for fuse access
comments inline
> diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
> index 05a364c54..b2dba9e 100644
> --- a/drivers/iio/magnetometer/Kconfig
> +++ b/drivers/iio/magnetometer/Kconfig
> @@ -17,6 +17,16 @@ config AK8975
> To compile this driver as a module, choose M here: the module
> will be called ak8975.
>
> +config AK09911
> + tristate "Asahi Kasei AK09911 3-axis Compass"
> + depends on I2C
> + help
> + Say yes here to build support for Asahi Kasei AK09911 3-Axis
> + Magnetometer.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called ak09911.
> +
> config MAG3110
> tristate "Freescale MAG3110 3-Axis Magnetometer"
> depends on I2C
> diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
> index 0f5d3c9..8526873 100644
> --- a/drivers/iio/magnetometer/Makefile
> +++ b/drivers/iio/magnetometer/Makefile
> @@ -4,6 +4,7 @@
>
> # When adding new entries keep the list in alphabetical order
> obj-$(CONFIG_AK8975) += ak8975.o
> +obj-$(CONFIG_AK09911) += ak09911.o
alphabetic, so before ak8975
> obj-$(CONFIG_MAG3110) += mag3110.o
> obj-$(CONFIG_HID_SENSOR_MAGNETOMETER_3D) += hid-sensor-magn-3d.o
>
> diff --git a/drivers/iio/magnetometer/ak09911.c b/drivers/iio/magnetometer/ak09911.c
> new file mode 100644
> index 0000000..6a69856
> --- /dev/null
> +++ b/drivers/iio/magnetometer/ak09911.c
> @@ -0,0 +1,346 @@
> +/*
> + * 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 RAW_TO_GAUSS(asa) ((((asa) + 128) * 6000) / 256)
prefix with AK09911_
> +
> +#define AK09911_MAX_CONVERSION_TIMEOUT 500
> +#define AK09911_CONVERSION_DONE_POLL_TIME 10
time unit?
> +
> +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] = RAW_TO_GAUSS(data->asa[0]);
> + data->raw_to_gauss[1] = RAW_TO_GAUSS(data->asa[1]);
> + data->raw_to_gauss[2] = 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,
> + 3, wia_val);
wia_val has just 2 bytes?! should be 2
> + 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;
> + int ret;
> +
> + /* Wait for the conversion to complete. */
> + while (timeout_ms) {
> + msleep_interruptible(AK09911_CONVERSION_DONE_POLL_TIME);
> + 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;
> + }
> + if (!timeout_ms) {
> + dev_err(&client->dev, "Conversion timeout happened\n");
> + return -EINVAL;
-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;
> + u16 meas_reg;
> + s16 raw;
> +
> + mutex_lock(&data->lock);
> +
> + ret = ak09911_set_mode(client, AK09911_MODE_SNG_MEASURE);
extra space before AK09911_MODE
> + 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;
> + }
> + meas_reg = ret;
> +
> + mutex_unlock(&data->lock);
> +
> + /* Endian conversion of the measured values. */
> + raw = (s16) (le16_to_cpu(meas_reg));
needed?
I think i2c_smbus_read_word_data() does the endianness conversion already
> +
> + /* Clamp to valid range. */
> + raw = clamp_t(s16, raw, -8192, 8192);
> + *val = raw;
> + 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;
> + char *name;
> + int ret;
> +
> + ret = ak09911_verify_chip_id(client);
> + if (ret) {
> + dev_err(&client->dev, "AK00911 not detected\n");
-ENODEV?
> + return -ENOSYS;
> + }
> +
> + 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 = (char *) id->name;
> + else if (ACPI_HANDLE(&client->dev))
> + name = (char *)dev_name(&client->dev);
> + else
> + return -ENOSYS;
> +
> + 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->name = id->name;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->name = name;
> + ret = iio_device_register(indio_dev);
>
devm_iio_device_register()
> + if (ret < 0)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int ak09911_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + iio_device_unregister(indio_dev);
can be dropped when using devm_iio_device_register()
> +
> + return 0;
> +}
> +
> +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,
> + .remove = ak09911_remove,
> + .id_table = ak09911_id,
> +};
> +module_i2c_driver(ak09911_driver);
> +
> +MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("AK09911 Compass driver");
>
--
Peter Meerwald
+43-664-2444418 (mobile)
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