iio: accel: Add buffer mode for Sensortek STK8312

Added triggered buffer mode support for the STK8312 accelerometer.

Additional changes:
- set_mode now sets operation mode directly, no longer masking
  the register's previous value
- read_accel now returns raw acceleration data instead of the
  sign_extend32 value
- read_raw will now enable/disable the sensor with each reading

Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Tiberiu Breana 2015-06-24 17:01:48 +03:00 committed by Jonathan Cameron
parent db6a19b825
commit 95c12bba51

View File

@ -11,16 +11,23 @@
*/
#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_STH 0x13
#define STK8312_REG_RESET 0x20
@ -29,14 +36,19 @@
#define STK8312_REG_OTPDATA 0x3E
#define STK8312_REG_OTPCTRL 0x3F
#define STK8312_MODE_ACTIVE 1
#define STK8312_MODE_STANDBY 0
#define STK8312_MODE_MASK 0x01
#define STK8312_MODE_ACTIVE 0x01
#define STK8312_MODE_STANDBY 0x00
#define STK8312_DREADY_BIT 0x10
#define STK8312_INT_MODE 0xC0
#define STK8312_RNG_MASK 0xC0
#define STK8312_RNG_SHIFT 6
#define STK8312_READ_RETRIES 16
#define STK8312_ALL_CHANNEL_MASK 7
#define STK8312_ALL_CHANNEL_SIZE 3
#define STK8312_DRIVER_NAME "stk8312"
#define STK8312_GPIO "stk8312_gpio"
#define STK8312_IRQ_NAME "stk8312_event"
/*
* The accelerometer has two measurement ranges:
@ -53,19 +65,27 @@ static const int stk8312_scale_table[][2] = {
{0, 461600}, {1, 231100}
};
#define STK8312_ACCEL_CHANNEL(reg, axis) { \
#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), \
.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(STK8312_REG_XOUT, X),
STK8312_ACCEL_CHANNEL(STK8312_REG_YOUT, Y),
STK8312_ACCEL_CHANNEL(STK8312_REG_ZOUT, Z),
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 {
@ -73,6 +93,9 @@ struct stk8312_data {
struct mutex lock;
int range;
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);
@ -130,31 +153,19 @@ static int stk8312_otp_init(struct stk8312_data *data)
static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
{
int ret;
u8 masked_reg;
struct i2c_client *client = data->client;
if (mode > 1)
return -EINVAL;
else if (mode == data->mode)
if (mode == data->mode)
return 0;
ret = i2c_smbus_read_byte_data(client, STK8312_REG_MODE);
if (ret < 0) {
dev_err(&client->dev, "failed to change sensor mode\n");
return ret;
}
masked_reg = ret & (~STK8312_MODE_MASK);
masked_reg |= mode;
ret = i2c_smbus_write_byte_data(client,
STK8312_REG_MODE, masked_reg);
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) {
if (mode & STK8312_MODE_ACTIVE) {
/* Need to run OTP sequence before entering active mode */
usleep_range(1000, 5000);
ret = stk8312_otp_init(data);
@ -163,6 +174,52 @@ static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
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");
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 ret;
}
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_range(struct stk8312_data *data, u8 range)
{
int ret;
@ -208,12 +265,10 @@ static int stk8312_read_accel(struct stk8312_data *data, u8 address)
return -EINVAL;
ret = i2c_smbus_read_byte_data(client, address);
if (ret < 0) {
if (ret < 0)
dev_err(&client->dev, "register read failed\n");
return ret;
}
return sign_extend32(ret, 7);
return ret;
}
static int stk8312_read_raw(struct iio_dev *indio_dev,
@ -221,14 +276,27 @@ static int stk8312_read_raw(struct iio_dev *indio_dev,
int *val, int *val2, long mask)
{
struct stk8312_data *data = iio_priv(indio_dev);
if (chan->type != IIO_ACCEL)
return -EINVAL;
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
mutex_lock(&data->lock);
*val = stk8312_read_accel(data, chan->address);
ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
if (ret < 0) {
mutex_unlock(&data->lock);
return -EINVAL;
}
ret = stk8312_read_accel(data, chan->address);
if (ret < 0) {
stk8312_set_mode(data,
data->mode & (~STK8312_MODE_ACTIVE));
mutex_unlock(&data->lock);
return -EINVAL;
}
*val = sign_extend32(ret, 7);
stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
mutex_unlock(&data->lock);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
@ -277,6 +345,109 @@ static const struct iio_info stk8312_info = {
.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;
u8 buffer[STK8312_ALL_CHANNEL_SIZE];
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,
buffer);
if (ret < STK8312_ALL_CHANNEL_SIZE) {
dev_err(&data->client->dev, "register read failed\n");
mutex_unlock(&data->lock);
goto err;
}
data->buffer[0] = buffer[0];
data->buffer[1] = buffer[1];
data->buffer[2] = buffer[2];
} 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_gpio_probe(struct i2c_client *client)
{
struct device *dev;
struct gpio_desc *gpio;
int ret;
if (!client)
return -EINVAL;
dev = &client->dev;
/* data ready gpio interrupt pin */
gpio = devm_gpiod_get_index(dev, STK8312_GPIO, 0, GPIOD_IN);
if (IS_ERR(gpio)) {
dev_err(dev, "acpi gpio get index failed\n");
return PTR_ERR(gpio);
}
ret = gpiod_to_irq(gpio);
dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
return ret;
}
static int stk8312_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@ -312,26 +483,85 @@ static int stk8312_probe(struct i2c_client *client,
if (ret < 0)
return ret;
ret = stk8312_set_mode(data, STK8312_MODE_ACTIVE);
ret = stk8312_set_mode(data, STK8312_INT_MODE | STK8312_MODE_ACTIVE);
if (ret < 0)
return ret;
if (client->irq < 0)
client->irq = stk8312_gpio_probe(client);
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");
stk8312_set_mode(data, STK8312_MODE_STANDBY);
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:
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);
return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY);
if (data->dready_trig)
iio_trigger_unregister(data->dready_trig);
return stk8312_set_mode(data, STK8312_MODE_STANDBY);
}
#ifdef CONFIG_PM_SLEEP
@ -341,7 +571,7 @@ static int stk8312_suspend(struct device *dev)
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return stk8312_set_mode(data, STK8312_MODE_STANDBY);
return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
}
static int stk8312_resume(struct device *dev)
@ -350,7 +580,7 @@ static int stk8312_resume(struct device *dev)
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return stk8312_set_mode(data, STK8312_MODE_ACTIVE);
return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
}
static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);