--- /dev/null
+/**
+ * Sensortek STK8312 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.
+ *
+ * IIO driver for STK8312; 7-bit I2C address: 0x3D.
+ */
+
+#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/delay.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 STK8312_REG_XOUT 0x00
+#define STK8312_REG_YOUT 0x01
+#define STK8312_REG_ZOUT 0x02
+#define STK8312_REG_INTSU 0x06
+#define STK8312_REG_MODE 0x07
+#define STK8312_REG_SR 0x08
+#define STK8312_REG_STH 0x13
+#define STK8312_REG_RESET 0x20
+#define STK8312_REG_AFECTRL 0x24
+#define STK8312_REG_OTPADDR 0x3D
+#define STK8312_REG_OTPDATA 0x3E
+#define STK8312_REG_OTPCTRL 0x3F
+
+#define STK8312_MODE_ACTIVE BIT(0)
+#define STK8312_MODE_STANDBY 0x00
+#define STK8312_MODE_INT_AH_PP 0xC0 /* active-high, push-pull */
+#define STK8312_DREADY_BIT BIT(4)
+#define STK8312_RNG_6G 1
+#define STK8312_RNG_SHIFT 6
+#define STK8312_RNG_MASK GENMASK(7, 6)
+#define STK8312_SR_MASK GENMASK(2, 0)
+#define STK8312_SR_400HZ_IDX 0
+#define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0)
+#define STK8312_ALL_CHANNEL_SIZE 3
+
+#define STK8312_DRIVER_NAME "stk8312"
+#define STK8312_IRQ_NAME "stk8312_event"
+
+/*
+ * The accelerometer has two measurement ranges:
+ *
+ * -6g - +6g (8-bit, signed)
+ * -16g - +16g (8-bit, signed)
+ *
+ * scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616
+ * scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311
+ */
+#define STK8312_SCALE_AVAIL "0.4616 1.2311"
+
+static const int stk8312_scale_table[][2] = {
+ {0, 461600}, {1, 231100}
+};
+
+static const struct {
+ int val;
+ int val2;
+} stk8312_samp_freq_table[] = {
+ {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
+ {12, 500000}, {6, 250000}, {3, 125000}
+};
+
+#define STK8312_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 = 8, \
+ .storagebits = 8, \
+ .endianness = IIO_CPU, \
+ }, \
+}
+
+static const struct iio_chan_spec stk8312_channels[] = {
+ STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),
+ STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),
+ STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),
+ IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+struct stk8312_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ u8 range;
+ u8 sample_rate_idx;
+ u8 mode;
+ struct iio_trigger *dready_trig;
+ bool dready_trigger_on;
+ s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
+};
+
+static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
+
+static struct attribute *stk8312_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 stk8312_attribute_group = {
+ .attrs = stk8312_attributes
+};
+
+static int stk8312_otp_init(struct stk8312_data *data)
+{
+ int ret;
+ int count = 10;
+ struct i2c_client *client = data->client;
+
+ ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
+ if (ret < 0)
+ goto exit_err;
+ ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
+ if (ret < 0)
+ goto exit_err;
+
+ do {
+ usleep_range(1000, 5000);
+ ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
+ if (ret < 0)
+ goto exit_err;
+ count--;
+ } while (!(ret & BIT(7)) && count > 0);
+
+ if (count == 0) {
+ ret = -ETIMEDOUT;
+ goto exit_err;
+ }
+
+ ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
+ if (ret == 0)
+ ret = -EINVAL;
+ if (ret < 0)
+ goto exit_err;
+
+ ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret);
+ if (ret < 0)
+ goto exit_err;
+ msleep(150);
+
+ return 0;
+
+exit_err:
+ dev_err(&client->dev, "failed to initialize sensor\n");
+ return ret;
+}
+
+static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
+{
+ int ret;
+ struct i2c_client *client = data->client;
+
+ if (mode == data->mode)
+ return 0;
+
+ ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to change sensor mode\n");
+ return ret;
+ }
+
+ data->mode = mode;
+ if (mode & STK8312_MODE_ACTIVE) {
+ /* Need to run OTP sequence before entering active mode */
+ usleep_range(1000, 5000);
+ ret = stk8312_otp_init(data);
+ }
+
+ return ret;
+}
+
+static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
+{
+ int ret;
+ u8 mode;
+ struct i2c_client *client = data->client;
+
+ mode = data->mode;
+ /* We need to go in standby mode to modify registers */
+ ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to set interrupts\n");
+ stk8312_set_mode(data, mode);
+ return ret;
+ }
+
+ return stk8312_set_mode(data, mode);
+}
+
+static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
+ bool state)
+{
+ struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+ struct stk8312_data *data = iio_priv(indio_dev);
+ int ret;
+
+ if (state)
+ ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
+ else
+ ret = stk8312_set_interrupts(data, 0x00);
+
+ if (ret < 0) {
+ dev_err(&data->client->dev, "failed to set trigger state\n");
+ return ret;
+ }
+
+ data->dready_trigger_on = state;
+
+ return 0;
+}
+
+static const struct iio_trigger_ops stk8312_trigger_ops = {
+ .set_trigger_state = stk8312_data_rdy_trigger_set_state,
+ .owner = THIS_MODULE,
+};
+
+static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)
+{
+ int ret;
+ u8 masked_reg;
+ u8 mode;
+ struct i2c_client *client = data->client;
+
+ if (rate == data->sample_rate_idx)
+ return 0;
+
+ mode = data->mode;
+ /* We need to go in standby mode to modify registers */
+ ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
+ if (ret < 0)
+ goto err_activate;
+
+ masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
+
+ ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
+ if (ret < 0)
+ goto err_activate;
+
+ data->sample_rate_idx = rate;
+
+ return stk8312_set_mode(data, mode);
+
+err_activate:
+ dev_err(&client->dev, "failed to set sampling rate\n");
+ stk8312_set_mode(data, mode);
+
+ return ret;
+}
+
+static int stk8312_set_range(struct stk8312_data *data, u8 range)
+{
+ int ret;
+ u8 masked_reg;
+ u8 mode;
+ struct i2c_client *client = data->client;
+
+ if (range != 1 && range != 2)
+ return -EINVAL;
+ else if (range == data->range)
+ return 0;
+
+ mode = data->mode;
+ /* We need to go in standby mode to modify registers */
+ ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
+ if (ret < 0)
+ goto err_activate;
+
+ masked_reg = ret & (~STK8312_RNG_MASK);
+ masked_reg |= range << STK8312_RNG_SHIFT;
+
+ ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
+ if (ret < 0)
+ goto err_activate;
+
+ data->range = range;
+
+ return stk8312_set_mode(data, mode);
+
+err_activate:
+ dev_err(&client->dev, "failed to change sensor range\n");
+ stk8312_set_mode(data, mode);
+
+ return ret;
+}
+
+static int stk8312_read_accel(struct stk8312_data *data, u8 address)
+{
+ int ret;
+ struct i2c_client *client = data->client;
+
+ if (address > 2)
+ return -EINVAL;
+
+ ret = i2c_smbus_read_byte_data(client, address);
+ if (ret < 0)
+ dev_err(&client->dev, "register read failed\n");
+
+ return ret;
+}
+
+static int stk8312_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct stk8312_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 = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+ ret = stk8312_read_accel(data, chan->address);
+ if (ret < 0) {
+ stk8312_set_mode(data,
+ data->mode & (~STK8312_MODE_ACTIVE));
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+ *val = sign_extend32(ret, 7);
+ ret = stk8312_set_mode(data,
+ data->mode & (~STK8312_MODE_ACTIVE));
+ mutex_unlock(&data->lock);
+ if (ret < 0)
+ return ret;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ *val = stk8312_scale_table[data->range - 1][0];
+ *val2 = stk8312_scale_table[data->range - 1][1];
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
+ *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+
+ return -EINVAL;
+}
+
+static int stk8312_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ int i;
+ int index = -1;
+ int ret;
+ struct stk8312_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
+ if (val == stk8312_scale_table[i][0] &&
+ val2 == stk8312_scale_table[i][1]) {
+ index = i + 1;
+ break;
+ }
+ if (index < 0)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = stk8312_set_range(data, index);
+ mutex_unlock(&data->lock);
+
+ return ret;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
+ if (val == stk8312_samp_freq_table[i].val &&
+ val2 == stk8312_samp_freq_table[i].val2) {
+ index = i;
+ break;
+ }
+ if (index < 0)
+ return -EINVAL;
+ mutex_lock(&data->lock);
+ ret = stk8312_set_sample_rate(data, index);
+ mutex_unlock(&data->lock);
+
+ return ret;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info stk8312_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = stk8312_read_raw,
+ .write_raw = stk8312_write_raw,
+ .attrs = &stk8312_attribute_group,
+};
+
+static irqreturn_t stk8312_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct stk8312_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 0x00 (XOUT) to 0x02 (ZOUT)
+ */
+ if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
+ ret = i2c_smbus_read_i2c_block_data(data->client,
+ STK8312_REG_XOUT,
+ STK8312_ALL_CHANNEL_SIZE,
+ data->buffer);
+ if (ret < STK8312_ALL_CHANNEL_SIZE) {
+ dev_err(&data->client->dev, "register read failed\n");
+ mutex_unlock(&data->lock);
+ goto err;
+ }
+ } else {
+ for_each_set_bit(bit, indio_dev->active_scan_mask,
+ indio_dev->masklength) {
+ ret = stk8312_read_accel(data, bit);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ goto err;
+ }
+ data->buffer[i++] = ret;
+ }
+ }
+ mutex_unlock(&data->lock);
+
+ iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+ pf->timestamp);
+err:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct stk8312_data *data = iio_priv(indio_dev);
+
+ if (data->dready_trigger_on)
+ iio_trigger_poll(data->dready_trig);
+
+ return IRQ_HANDLED;
+}
+
+static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
+{
+ struct stk8312_data *data = iio_priv(indio_dev);
+
+ return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
+}
+
+static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
+{
+ struct stk8312_data *data = iio_priv(indio_dev);
+
+ return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
+}
+
+static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
+ .preenable = stk8312_buffer_preenable,
+ .postenable = iio_triggered_buffer_postenable,
+ .predisable = iio_triggered_buffer_predisable,
+ .postdisable = stk8312_buffer_postdisable,
+};
+
+static int stk8312_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct stk8312_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 = &stk8312_info;
+ indio_dev->name = STK8312_DRIVER_NAME;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = stk8312_channels;
+ indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
+
+ /* A software reset is recommended at power-on */
+ ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to reset sensor\n");
+ return ret;
+ }
+ data->sample_rate_idx = STK8312_SR_400HZ_IDX;
+ ret = stk8312_set_range(data, STK8312_RNG_6G);
+ if (ret < 0)
+ return ret;
+
+ ret = stk8312_set_mode(data,
+ STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE);
+ if (ret < 0)
+ return ret;
+
+ if (client->irq > 0) {
+ ret = devm_request_threaded_irq(&client->dev, client->irq,
+ stk8312_data_rdy_trig_poll,
+ NULL,
+ IRQF_TRIGGER_RISING |
+ IRQF_ONESHOT,
+ STK8312_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 = &stk8312_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,
+ stk8312_trigger_handler,
+ &stk8312_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 0;
+
+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:
+ stk8312_set_mode(data, STK8312_MODE_STANDBY);
+ return ret;
+}
+
+static int stk8312_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct stk8312_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 stk8312_set_mode(data, STK8312_MODE_STANDBY);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stk8312_suspend(struct device *dev)
+{
+ struct stk8312_data *data;
+
+ data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+ return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
+}
+
+static int stk8312_resume(struct device *dev)
+{
+ struct stk8312_data *data;
+
+ data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+ return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
+}
+
+static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
+
+#define STK8312_PM_OPS (&stk8312_pm_ops)
+#else
+#define STK8312_PM_OPS NULL
+#endif
+
+static const struct i2c_device_id stk8312_i2c_id[] = {
+ {"STK8312", 0},
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
+
+static const struct acpi_device_id stk8312_acpi_id[] = {
+ {"STK8312", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
+
+static struct i2c_driver stk8312_driver = {
+ .driver = {
+ .name = STK8312_DRIVER_NAME,
+ .pm = STK8312_PM_OPS,
+ .acpi_match_table = ACPI_PTR(stk8312_acpi_id),
+ },
+ .probe = stk8312_probe,
+ .remove = stk8312_remove,
+ .id_table = stk8312_i2c_id,
+};
+
+module_i2c_driver(stk8312_driver);
+
+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
+MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff