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@xxxxxxxxx>
---
v2 changes:
- addressed Jon's feedback
- changed some defines for a more accurate description
- added padding bits to the buffer
---
drivers/iio/accel/stk8312.c | 284 ++++++++++++++++++++++++++++++++++++++------
1 file changed, 248 insertions(+), 36 deletions(-)
diff --git a/drivers/iio/accel/stk8312.c b/drivers/iio/accel/stk8312.c
index d211d9f3..aba209b 100644
--- a/drivers/iio/accel/stk8312.c
+++ b/drivers/iio/accel/stk8312.c
@@ -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 +36,16 @@
#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_POWER_BIT 0x01
+#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_DRIVER_NAME "stk8312"
+#define STK8312_GPIO "stk8312_gpio"
+#define STK8312_IRQ_NAME "stk8312_event"
/*
* The accelerometer has two measurement ranges:
@@ -53,19 +62,27 @@ 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 +90,9 @@ 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 +150,19 @@ exit_err:
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_POWER_BIT) {
/* Need to run OTP sequence before entering active mode */
usleep_range(1000, 5000);
ret = stk8312_otp_init(data);
@@ -163,6 +171,52 @@ 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_POWER_BIT);
+ 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, !STK8312_DREADY_BIT);
+
+ 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;
@@ -177,7 +231,7 @@ static int stk8312_set_range(struct stk8312_data *data, u8 range)
mode = data->mode;
/* We need to go in standby mode to modify registers */
- ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
+ ret = stk8312_set_mode(data, !STK8312_POWER_BIT);
if (ret < 0)
return ret;
@@ -208,12 +262,10 @@ 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 +273,27 @@ 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_POWER_BIT);
+ 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_POWER_BIT));
+ mutex_unlock(&data->lock);
+ return -EINVAL;
+ }
+ *val = sign_extend32(ret, 7);
+ stk8312_set_mode(data, data->mode & (~STK8312_POWER_BIT));
mutex_unlock(&data->lock);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
@@ -277,6 +342,93 @@ 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;
+
+ mutex_lock(&data->lock);
+ 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_POWER_BIT);
+}
+
+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_POWER_BIT));
+}
+
+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);
+ if (IS_ERR(gpio)) {
+ dev_err(dev, "acpi gpio get index failed\n");
+ return PTR_ERR(gpio);
+ }
+
+ ret = gpiod_direction_input(gpio);
+ if (ret)
+ return ret;
+
+ 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 +464,86 @@ 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_POWER_BIT);
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_POWER_BIT);
+ 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);
- return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY);
+ if (data->dready_trig) {
+ iio_triggered_buffer_cleanup(indio_dev);
+ iio_trigger_unregister(data->dready_trig);
+ }
+
+ return stk8312_set_mode(data, !STK8312_POWER_BIT);
}
#ifdef CONFIG_PM_SLEEP
@@ -341,7 +553,7 @@ 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_POWER_BIT));
}
static int stk8312_resume(struct device *dev)
@@ -350,7 +562,7 @@ 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_POWER_BIT);
}
static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
--
1.9.1
--
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