3 files changed, 412 insertions, 0 deletions

diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
index 4fa923f37b97..0cf09637b35b 100644
--- a/drivers/iio/magnetometer/Kconfig
+++ b/drivers/iio/magnetometer/Kconfig
@@ -16,6 +16,16 @@ config AK8975
           To compile this driver as a module, choose M here: the module
           will be called ak8975.
 
+config MAG3110
+        tristate "Freescale MAG3110 3-Axis Magnetometer"
+        depends on I2C
+        help
+          Say yes here to build support for the Freescale MAG3110 3-Axis
+          magnetometer.
+
+          To compile this driver as a module, choose M here: the module
+          will be called mag3110.
+
 config HID_SENSOR_MAGNETOMETER_3D
         depends on HID_SENSOR_HUB
         select IIO_BUFFER
diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
index f91b1b68d392..0f5d3c985799 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_MAG3110)   += mag3110.o
 obj-$(CONFIG_HID_SENSOR_MAGNETOMETER_3D) += hid-sensor-magn-3d.o
 
 obj-$(CONFIG_IIO_ST_MAGN_3AXIS) += st_magn.o
diff --git a/drivers/iio/magnetometer/mag3110.c b/drivers/iio/magnetometer/mag3110.c
new file mode 100644
index 000000000000..783c5b417356
--- /dev/null
+++ b/drivers/iio/magnetometer/mag3110.c
@@ -0,0 +1,401 @@
+/*
+ * mag3110.c - Support for Freescale MAG3110 magnetometer sensor
+ *
+ * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License.  See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * (7-bit I2C slave address 0x0e)
+ *
+ * TODO: irq, user offset, oversampling, continuous mode
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/delay.h>
+
+#define MAG3110_STATUS 0x00
+#define MAG3110_OUT_X 0x01 /* MSB first */
+#define MAG3110_OUT_Y 0x03
+#define MAG3110_OUT_Z 0x05
+#define MAG3110_WHO_AM_I 0x07
+#define MAG3110_OFF_X 0x09 /* MSB first */
+#define MAG3110_OFF_Y 0x0b
+#define MAG3110_OFF_Z 0x0d
+#define MAG3110_DIE_TEMP 0x0f
+#define MAG3110_CTRL_REG1 0x10
+#define MAG3110_CTRL_REG2 0x11
+
+#define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
+
+#define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))
+#define MAG3110_CTRL_DR_SHIFT 5
+#define MAG3110_CTRL_DR_DEFAULT 0
+
+#define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
+#define MAG3110_CTRL_AC BIT(0) /* continuous measurements */
+
+#define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
+#define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */
+
+#define MAG3110_DEVICE_ID 0xc4
+
+/* Each client has this additional data */
+struct mag3110_data {
+        struct i2c_client *client;
+        struct mutex lock;
+        u8 ctrl_reg1;
+};
+
+static int mag3110_request(struct mag3110_data *data)
+{
+        int ret, tries = 150;
+
+        /* trigger measurement */
+        ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
+                data->ctrl_reg1 | MAG3110_CTRL_TM);
+        if (ret < 0)
+                return ret;
+
+        while (tries-- > 0) {
+                ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
+                if (ret < 0)
+                        return ret;
+                /* wait for data ready */
+                if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
+                        break;
+                msleep(20);
+        }
+
+        if (tries < 0) {
+                dev_err(&data->client->dev, "data not ready\n");
+                return -EIO;
+        }
+
+        return 0;
+}
+
+static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
+{
+        int ret;
+
+        mutex_lock(&data->lock);
+        ret = mag3110_request(data);
+        if (ret < 0) {
+                mutex_unlock(&data->lock);
+                return ret;
+        }
+        ret = i2c_smbus_read_i2c_block_data(data->client,
+                MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
+        mutex_unlock(&data->lock);
+
+        return ret;
+}
+
+static ssize_t mag3110_show_int_plus_micros(char *buf,
+        const int (*vals)[2], int n)
+{
+        size_t len = 0;
+
+        while (n-- > 0)
+                len += scnprintf(buf + len, PAGE_SIZE - len,
+                        "%d.%d ", vals[n][0], vals[n][1]);
+
+        /* replace trailing space by newline */
+        buf[len - 1] = '\n';
+
+        return len;
+}
+
+static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
+                                        int val, int val2)
+{
+        while (n-- > 0)
+                if (val == vals[n][0] && val2 == vals[n][1])
+                        return n;
+
+        return -EINVAL;
+}
+
+static const int mag3110_samp_freq[8][2] = {
+        {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
+        {1, 250000}, {0, 625000}
+};
+
+static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
+
+static int mag3110_get_samp_freq_index(struct mag3110_data *data,
+        int val, int val2)
+{
+        return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
+                val2);
+}
+
+static int mag3110_read_raw(struct iio_dev *indio_dev,
+                            struct iio_chan_spec const *chan,
+                            int *val, int *val2, long mask)
+{
+        struct mag3110_data *data = iio_priv(indio_dev);
+        __be16 buffer[3];
+        int i, ret;
+
+        switch (mask) {
+        case IIO_CHAN_INFO_RAW:
+                switch (chan->type) {
+                case IIO_MAGN: /* in 0.1 uT / LSB */
+                        ret = mag3110_read(data, buffer);
+                        if (ret < 0)
+                                return ret;
+                        *val = sign_extend32(
+                                be16_to_cpu(buffer[chan->scan_index]), 15);
+                        return IIO_VAL_INT;
+                case IIO_TEMP: /* in 1 C / LSB */
+                        mutex_lock(&data->lock);
+                        ret = mag3110_request(data);
+                        if (ret < 0) {
+                                mutex_unlock(&data->lock);
+                                return ret;
+                        }
+                        ret = i2c_smbus_read_byte_data(data->client,
+                                MAG3110_DIE_TEMP);
+                        mutex_unlock(&data->lock);
+                        if (ret < 0)
+                                return ret;
+                        *val = sign_extend32(ret, 7);
+                        return IIO_VAL_INT;
+                default:
+                        return -EINVAL;
+                }
+        case IIO_CHAN_INFO_SCALE:
+                *val = 0;
+                *val2 = 1000;
+                return IIO_VAL_INT_PLUS_MICRO;
+        case IIO_CHAN_INFO_SAMP_FREQ:
+                i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
+                *val = mag3110_samp_freq[i][0];
+                *val2 = mag3110_samp_freq[i][1];
+                return IIO_VAL_INT_PLUS_MICRO;
+        }
+        return -EINVAL;
+}
+
+static int mag3110_write_raw(struct iio_dev *indio_dev,
+                             struct iio_chan_spec const *chan,
+                             int val, int val2, long mask)
+{
+        struct mag3110_data *data = iio_priv(indio_dev);
+        int rate;
+
+        switch (mask) {
+        case IIO_CHAN_INFO_SAMP_FREQ:
+                rate = mag3110_get_samp_freq_index(data, val, val2);
+                if (rate < 0)
+                        return -EINVAL;
+
+                data->ctrl_reg1 &= ~MAG3110_CTRL_DR_MASK;
+                data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
+                return i2c_smbus_write_byte_data(data->client,
+                        MAG3110_CTRL_REG1, data->ctrl_reg1);
+        default:
+                return -EINVAL;
+        }
+}
+
+static irqreturn_t mag3110_trigger_handler(int irq, void *p)
+{
+        struct iio_poll_func *pf = p;
+        struct iio_dev *indio_dev = pf->indio_dev;
+        struct mag3110_data *data = iio_priv(indio_dev);
+        u8 buffer[16]; /* 3 16-bit channels + 1 byte temp + padding + ts */
+        int ret;
+
+        ret = mag3110_read(data, (__be16 *) buffer);
+        if (ret < 0)
+                goto done;
+
+        if (test_bit(3, indio_dev->active_scan_mask)) {
+                ret = i2c_smbus_read_byte_data(data->client,
+                        MAG3110_DIE_TEMP);
+                if (ret < 0)
+                        goto done;
+                buffer[6] = ret;
+        }
+
+        iio_push_to_buffers_with_timestamp(indio_dev, buffer,
+                iio_get_time_ns());
+
+done:
+        iio_trigger_notify_done(indio_dev->trig);
+        return IRQ_HANDLED;
+}
+
+#define MAG3110_CHANNEL(axis, idx) { \
+        .type = IIO_MAGN, \
+        .modified = 1, \
+        .channel2 = IIO_MOD_##axis, \
+        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+        .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
+                BIT(IIO_CHAN_INFO_SCALE), \
+        .scan_index = idx, \
+        .scan_type = IIO_ST('s', 16, 16, IIO_BE), \
+}
+
+static const struct iio_chan_spec mag3110_channels[] = {
+        MAG3110_CHANNEL(X, 0),
+        MAG3110_CHANNEL(Y, 1),
+        MAG3110_CHANNEL(Z, 2),
+        {
+                .type = IIO_TEMP,
+                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+                .scan_index = 3,
+                .scan_type = IIO_ST('s', 8, 8, 0),
+        },
+        IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static struct attribute *mag3110_attributes[] = {
+        &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group mag3110_group = {
+        .attrs = mag3110_attributes,
+};
+
+static const struct iio_info mag3110_info = {
+        .attrs = &mag3110_group,
+        .read_raw = &mag3110_read_raw,
+        .write_raw = &mag3110_write_raw,
+        .driver_module = THIS_MODULE,
+};
+
+static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};
+
+static int mag3110_probe(struct i2c_client *client,
+                         const struct i2c_device_id *id)
+{
+        struct mag3110_data *data;
+        struct iio_dev *indio_dev;
+        int ret;
+
+        ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
+        if (ret < 0)
+                return ret;
+        if (ret != MAG3110_DEVICE_ID)
+                return -ENODEV;
+
+        indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+        if (!indio_dev)
+                return -ENOMEM;
+
+        data = iio_priv(indio_dev);
+        data->client = client;
+        mutex_init(&data->lock);
+
+        i2c_set_clientdata(client, indio_dev);
+        indio_dev->info = &mag3110_info;
+        indio_dev->name = id->name;
+        indio_dev->dev.parent = &client->dev;
+        indio_dev->modes = INDIO_DIRECT_MODE;
+        indio_dev->channels = mag3110_channels;
+        indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
+        indio_dev->available_scan_masks = mag3110_scan_masks;
+
+        data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT;
+        ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG1,
+                data->ctrl_reg1);
+        if (ret < 0)
+                return ret;
+
+        ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
+                MAG3110_CTRL_AUTO_MRST_EN | MAG3110_CTRL_RAW);
+        if (ret < 0)
+                return ret;
+
+        ret = iio_triggered_buffer_setup(indio_dev, NULL,
+                mag3110_trigger_handler, NULL);
+        if (ret < 0)
+                return ret;
+
+        ret = iio_device_register(indio_dev);
+        if (ret < 0)
+                goto buffer_cleanup;
+        return 0;
+
+buffer_cleanup:
+        iio_triggered_buffer_cleanup(indio_dev);
+        return ret;
+}
+
+static int mag3110_standby(struct mag3110_data *data)
+{
+        return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
+                data->ctrl_reg1 & ~MAG3110_CTRL_AC);
+}
+
+static int mag3110_remove(struct i2c_client *client)
+{
+        struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+        iio_device_unregister(indio_dev);
+        iio_triggered_buffer_cleanup(indio_dev);
+        mag3110_standby(iio_priv(indio_dev));
+
+        return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mag3110_suspend(struct device *dev)
+{
+        return mag3110_standby(iio_priv(i2c_get_clientdata(
+                to_i2c_client(dev))));
+}
+
+static int mag3110_resume(struct device *dev)
+{
+        struct mag3110_data *data = iio_priv(i2c_get_clientdata(
+                to_i2c_client(dev)));
+
+        return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
+                data->ctrl_reg1);
+}
+
+static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume);
+#define MAG3110_PM_OPS (&mag3110_pm_ops)
+#else
+#define MAG3110_PM_OPS NULL
+#endif
+
+static const struct i2c_device_id mag3110_id[] = {
+        { "mag3110", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, mag3110_id);
+
+static struct i2c_driver mag3110_driver = {
+        .driver = {
+                .name   = "mag3110",
+                .pm     = MAG3110_PM_OPS,
+        },
+        .probe = mag3110_probe,
+        .remove = mag3110_remove,
+        .id_table = mag3110_id,
+};
+module_i2c_driver(mag3110_driver);
+
+MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
+MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
+MODULE_LICENSE("GPL");