--- /dev/null
+/**
+ * Sensortek STK8BA50 3-Axis Accelerometer
+ *
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * 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.
+ *
+ * STK8BA50 7-bit I2C address: 0x18.
+ */
+
+#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#define STK8BA50_REG_XOUT 0x02
+#define STK8BA50_REG_YOUT 0x04
+#define STK8BA50_REG_ZOUT 0x06
+#define STK8BA50_REG_RANGE 0x0F
+#define STK8BA50_REG_BWSEL 0x10
+#define STK8BA50_REG_POWMODE 0x11
+#define STK8BA50_REG_SWRST 0x14
+#define STK8BA50_REG_INTEN2 0x17
+#define STK8BA50_REG_INTMAP2 0x1A
+
+#define STK8BA50_MODE_NORMAL 0
+#define STK8BA50_MODE_SUSPEND 1
+#define STK8BA50_MODE_POWERBIT BIT(7)
+#define STK8BA50_DATA_SHIFT 6
+#define STK8BA50_RESET_CMD 0xB6
+#define STK8BA50_SR_1792HZ_IDX 7
+#define STK8BA50_DREADY_INT_MASK 0x10
+#define STK8BA50_DREADY_INT_MAP 0x81
+#define STK8BA50_ALL_CHANNEL_MASK 7
+#define STK8BA50_ALL_CHANNEL_SIZE 6
+
+#define STK8BA50_DRIVER_NAME "stk8ba50"
+#define STK8BA50_IRQ_NAME "stk8ba50_event"
+
+#define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069"
+
+/*
+ * The accelerometer has four measurement ranges:
+ * +/-2g; +/-4g; +/-8g; +/-16g
+ *
+ * Acceleration values are 10-bit, 2's complement.
+ * Scales are calculated as following:
+ *
+ * scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384
+ * scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767
+ * etc.
+ *
+ * Scales are stored in this format:
+ * { <register value>, <scale value> }
+ *
+ * Locally, the range is stored as a table index.
+ */
+static const struct {
+ u8 reg_val;
+ u32 scale_val;
+} stk8ba50_scale_table[] = {
+ {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
+};
+
+/* Sample rates are stored as { <register value>, <Hz value> } */
+static const struct {
+ u8 reg_val;
+ u16 samp_freq;
+} stk8ba50_samp_freq_table[] = {
+ {0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112},
+ {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
+};
+
+/* Used to map scan mask bits to their corresponding channel register. */
+static const int stk8ba50_channel_table[] = {
+ STK8BA50_REG_XOUT,
+ STK8BA50_REG_YOUT,
+ STK8BA50_REG_ZOUT
+};
+
+struct stk8ba50_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ int range;
+ u8 sample_rate_idx;
+ struct iio_trigger *dready_trig;
+ bool dready_trigger_on;
+ /*
+ * 3 x 16-bit channels (10-bit data, 6-bit padding) +
+ * 1 x 16 padding +
+ * 4 x 16 64-bit timestamp
+ */
+ s16 buffer[8];
+};
+
+#define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \
+ .type = IIO_ACCEL, \
+ .address = reg, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_##axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .scan_index = index, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 10, \
+ .storagebits = 16, \
+ .shift = STK8BA50_DATA_SHIFT, \
+ .endianness = IIO_CPU, \
+ }, \
+}
+
+static const struct iio_chan_spec stk8ba50_channels[] = {
+ STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
+ STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
+ STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
+ IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
+
+static struct attribute *stk8ba50_attributes[] = {
+ &iio_const_attr_in_accel_scale_available.dev_attr.attr,
+ &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group stk8ba50_attribute_group = {
+ .attrs = stk8ba50_attributes
+};
+
+static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
+{
+ int ret;
+ struct i2c_client *client = data->client;
+
+ ret = i2c_smbus_read_word_data(client, reg);
+ if (ret < 0) {
+ dev_err(&client->dev, "register read failed\n");
+ return ret;
+ }
+
+ return ret;
+}
+
+static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
+ bool state)
+{
+ struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+ struct stk8ba50_data *data = iio_priv(indio_dev);
+ int ret;
+
+ if (state)
+ ret = i2c_smbus_write_byte_data(data->client,
+ STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
+ else
+ ret = i2c_smbus_write_byte_data(data->client,
+ STK8BA50_REG_INTEN2, 0x00);
+
+ if (ret < 0)
+ dev_err(&data->client->dev, "failed to set trigger state\n");
+ else
+ data->dready_trigger_on = state;
+
+ return ret;
+}
+
+static const struct iio_trigger_ops stk8ba50_trigger_ops = {
+ .set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
+ .owner = THIS_MODULE,
+};
+
+static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
+{
+ int ret;
+ u8 masked_reg;
+ struct i2c_client *client = data->client;
+
+ ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
+ if (ret < 0)
+ goto exit_err;
+
+ if (mode)
+ masked_reg = ret | STK8BA50_MODE_POWERBIT;
+ else
+ masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
+
+ ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
+ masked_reg);
+ if (ret < 0)
+ goto exit_err;
+
+ return ret;
+
+exit_err:
+ dev_err(&client->dev, "failed to change sensor mode\n");
+ return ret;
+}
+
+static int stk8ba50_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct stk8ba50_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (iio_buffer_enabled(indio_dev))
+ return -EBUSY;
+ mutex_lock(&data->lock);
+ ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return -EINVAL;
+ }
+ ret = stk8ba50_read_accel(data, chan->address);
+ if (ret < 0) {
+ stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+ mutex_unlock(&data->lock);
+ return -EINVAL;
+ }
+ *val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
+ stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+ mutex_unlock(&data->lock);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = 0;
+ *val2 = stk8ba50_scale_table[data->range].scale_val;
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = stk8ba50_samp_freq_table
+ [data->sample_rate_idx].samp_freq;
+ *val2 = 0;
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static int stk8ba50_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ int ret;
+ int i;
+ int index = -1;
+ struct stk8ba50_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ if (val != 0)
+ return -EINVAL;
+
+ for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
+ if (val2 == stk8ba50_scale_table[i].scale_val) {
+ index = i;
+ break;
+ }
+ if (index < 0)
+ return -EINVAL;
+
+ ret = i2c_smbus_write_byte_data(data->client,
+ STK8BA50_REG_RANGE,
+ stk8ba50_scale_table[index].reg_val);
+ if (ret < 0)
+ dev_err(&data->client->dev,
+ "failed to set measurement range\n");
+ else
+ data->range = index;
+
+ return ret;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
+ if (val == stk8ba50_samp_freq_table[i].samp_freq) {
+ index = i;
+ break;
+ }
+ if (index < 0)
+ return -EINVAL;
+
+ ret = i2c_smbus_write_byte_data(data->client,
+ STK8BA50_REG_BWSEL,
+ stk8ba50_samp_freq_table[index].reg_val);
+ if (ret < 0)
+ dev_err(&data->client->dev,
+ "failed to set sampling rate\n");
+ else
+ data->sample_rate_idx = index;
+
+ return ret;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info stk8ba50_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = stk8ba50_read_raw,
+ .write_raw = stk8ba50_write_raw,
+ .attrs = &stk8ba50_attribute_group,
+};
+
+static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct stk8ba50_data *data = iio_priv(indio_dev);
+ int bit, ret, i = 0;
+
+ mutex_lock(&data->lock);
+ /*
+ * Do a bulk read if all channels are requested,
+ * from 0x02 (XOUT1) to 0x07 (ZOUT2)
+ */
+ if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
+ ret = i2c_smbus_read_i2c_block_data(data->client,
+ STK8BA50_REG_XOUT,
+ STK8BA50_ALL_CHANNEL_SIZE,
+ (u8 *)data->buffer);
+ if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
+ dev_err(&data->client->dev, "register read failed\n");
+ goto err;
+ }
+ } else {
+ for_each_set_bit(bit, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ ret = stk8ba50_read_accel(data,
+ stk8ba50_channel_table[bit]);
+ if (ret < 0)
+ goto err;
+
+ data->buffer[i++] = ret;
+ }
+ }
+ iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ pf->timestamp);
+err:
+ mutex_unlock(&data->lock);
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct stk8ba50_data *data = iio_priv(indio_dev);
+
+ if (data->dready_trigger_on)
+ iio_trigger_poll(data->dready_trig);
+
+ return IRQ_HANDLED;
+}
+
+static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
+{
+ struct stk8ba50_data *data = iio_priv(indio_dev);
+
+ return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
+}
+
+static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
+{
+ struct stk8ba50_data *data = iio_priv(indio_dev);
+
+ return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+}
+
+static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
+ .preenable = stk8ba50_buffer_preenable,
+ .postenable = iio_triggered_buffer_postenable,
+ .predisable = iio_triggered_buffer_predisable,
+ .postdisable = stk8ba50_buffer_postdisable,
+};
+
+static int stk8ba50_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct stk8ba50_data *data;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev) {
+ dev_err(&client->dev, "iio allocation failed!\n");
+ return -ENOMEM;
+ }
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+ i2c_set_clientdata(client, indio_dev);
+ mutex_init(&data->lock);
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &stk8ba50_info;
+ indio_dev->name = STK8BA50_DRIVER_NAME;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = stk8ba50_channels;
+ indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);
+
+ /* Reset all registers on startup */
+ ret = i2c_smbus_write_byte_data(client,
+ STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to reset sensor\n");
+ goto err_power_off;
+ }
+
+ /* The default range is +/-2g */
+ data->range = 0;
+
+ /* The default sampling rate is 1792 Hz (maximum) */
+ data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
+
+ /* Set up interrupts */
+ ret = i2c_smbus_write_byte_data(client,
+ STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to set up interrupts\n");
+ goto err_power_off;
+ }
+ ret = i2c_smbus_write_byte_data(client,
+ STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to set up interrupts\n");
+ goto err_power_off;
+ }
+
+ if (client->irq > 0) {
+ ret = devm_request_threaded_irq(&client->dev, client->irq,
+ stk8ba50_data_rdy_trig_poll,
+ NULL,
+ IRQF_TRIGGER_RISING |
+ IRQF_ONESHOT,
+ STK8BA50_IRQ_NAME,
+ indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "request irq %d failed\n",
+ client->irq);
+ goto err_power_off;
+ }
+
+ data->dready_trig = devm_iio_trigger_alloc(&client->dev,
+ "%s-dev%d",
+ indio_dev->name,
+ indio_dev->id);
+ if (!data->dready_trig) {
+ ret = -ENOMEM;
+ goto err_power_off;
+ }
+
+ data->dready_trig->dev.parent = &client->dev;
+ data->dready_trig->ops = &stk8ba50_trigger_ops;
+ iio_trigger_set_drvdata(data->dready_trig, indio_dev);
+ ret = iio_trigger_register(data->dready_trig);
+ if (ret) {
+ dev_err(&client->dev, "iio trigger register failed\n");
+ goto err_power_off;
+ }
+ }
+
+ ret = iio_triggered_buffer_setup(indio_dev,
+ iio_pollfunc_store_time,
+ stk8ba50_trigger_handler,
+ &stk8ba50_buffer_setup_ops);
+ if (ret < 0) {
+ dev_err(&client->dev, "iio triggered buffer setup failed\n");
+ goto err_trigger_unregister;
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "device_register failed\n");
+ goto err_buffer_cleanup;
+ }
+
+ return ret;
+
+err_buffer_cleanup:
+ iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+ if (data->dready_trig)
+ iio_trigger_unregister(data->dready_trig);
+err_power_off:
+ stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+ return ret;
+}
+
+static int stk8ba50_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct stk8ba50_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ iio_triggered_buffer_cleanup(indio_dev);
+
+ if (data->dready_trig)
+ iio_trigger_unregister(data->dready_trig);
+
+ return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stk8ba50_suspend(struct device *dev)
+{
+ struct stk8ba50_data *data;
+
+ data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+ return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+}
+
+static int stk8ba50_resume(struct device *dev)
+{
+ struct stk8ba50_data *data;
+
+ data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+ return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
+}
+
+static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume);
+
+#define STK8BA50_PM_OPS (&stk8ba50_pm_ops)
+#else
+#define STK8BA50_PM_OPS NULL
+#endif
+
+static const struct i2c_device_id stk8ba50_i2c_id[] = {
+ {"stk8ba50", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id);
+
+static const struct acpi_device_id stk8ba50_acpi_id[] = {
+ {"STK8BA50", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);
+
+static struct i2c_driver stk8ba50_driver = {
+ .driver = {
+ .name = "stk8ba50",
+ .pm = STK8BA50_PM_OPS,
+ .acpi_match_table = ACPI_PTR(stk8ba50_acpi_id),
+ },
+ .probe = stk8ba50_probe,
+ .remove = stk8ba50_remove,
+ .id_table = stk8ba50_i2c_id,
+};
+
+module_i2c_driver(stk8ba50_driver);
+
+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
+MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff