> Add data-ready interrupts and trigger support for STK8BA50.
>
> Additional changes:
> - read_accel now returns raw acceleration data instead of the
> sign_extend32 value
> - read_raw will now enable/disable the sensor with each reading
comments below
> Signed-off-by: Tiberiu Breana <tiberiu.a.breana@xxxxxxxxx>
> ---
> drivers/iio/accel/stk8ba50.c | 281 +++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 256 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/iio/accel/stk8ba50.c b/drivers/iio/accel/stk8ba50.c
> index 9836880..dd4f0da 100644
> --- a/drivers/iio/accel/stk8ba50.c
> +++ b/drivers/iio/accel/stk8ba50.c
> @@ -11,11 +11,17 @@
> */
>
> #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
> @@ -24,6 +30,8 @@
> #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
> @@ -31,8 +39,12 @@
> #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_DRIVER_NAME "stk8ba50"
> +#define STK8BA50_GPIO "stk8ba50_gpio"
> +#define STK8BA50_IRQ_NAME "stk8ba50_event"
>
> #define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069"
>
> @@ -73,9 +85,17 @@ struct stk8ba50_data {
> 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(reg, axis) { \
> +#define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \
> .type = IIO_ACCEL, \
> .address = reg, \
> .modified = 1, \
> @@ -83,12 +103,20 @@ struct stk8ba50_data {
> .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, \
there is a .shift field which might be useful!
> + .endianness = IIO_CPU, \
> + }, \
> }
>
> static const struct iio_chan_spec stk8ba50_channels[] = {
> - STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_XOUT, X),
> - STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_YOUT, Y),
> - STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_ZOUT, Z),
> + 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);
> @@ -116,7 +144,61 @@ static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
> return ret;
> }
>
> - return sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
> + return ret >> STK8BA50_DATA_SHIFT;
I think this should be done in _read_raw() only, not here;
this allows to use _read_accel() in the trigger handler without
manipulating the data (+ using .shift)
> +}
> +
> +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,
> @@ -124,11 +206,26 @@ static int stk8ba50_read_raw(struct iio_dev *indio_dev,
> 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);
> - *val = stk8ba50_read_accel(data, chan->address);
> + 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, 9);
let's do the shifting here as well...
> + stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
> mutex_unlock(&data->lock);
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_SCALE:
> @@ -208,30 +305,98 @@ static const struct iio_info stk8ba50_info = {
> .attrs = &stk8ba50_attribute_group,
> };
>
> -static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
> +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;
> +
perhaps it is possible to optimize for the likely case of reading all
three channels at once?
> + mutex_lock(&data->lock);
> + for_each_set_bit(bit, indio_dev->active_scan_mask,
> + indio_dev->masklength) {
> + switch (bit) {
> + case 0:
> + ret = stk8ba50_read_accel(data, STK8BA50_REG_XOUT);
> + break;
> + case 1:
> + ret = stk8ba50_read_accel(data, STK8BA50_REG_YOUT);
> + break;
> + case 2:
> + ret = stk8ba50_read_accel(data, STK8BA50_REG_ZOUT);
> + break;
> + default:
> + return -EINVAL;
> + }
> + 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 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_gpio_probe(struct i2c_client *client)
> +{
> + struct device *dev;
> + struct gpio_desc *gpio;
> 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 (!client)
> + return -EINVAL;
>
> - if (mode)
> - masked_reg = ret | STK8BA50_MODE_POWERBIT;
> - else
> - masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
> + dev = &client->dev;
>
> - ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
> - masked_reg);
> - if (ret < 0)
> - goto exit_err;
> + /* data ready gpio interrupt pin */
> + gpio = devm_gpiod_get_index(dev, STK8BA50_GPIO, 0, GPIOD_IN);
> + if (IS_ERR(gpio)) {
> + dev_err(dev, "acpi gpio get index failed\n");
> + return PTR_ERR(gpio);
> + }
>
> - return ret;
> + ret = gpiod_to_irq(gpio);
> + dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
>
> -exit_err:
> - dev_err(&client->dev, "failed to change sensor mode\n");
> return ret;
> }
>
> @@ -274,14 +439,74 @@ static int stk8ba50_probe(struct i2c_client *client,
> /* 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);
> + 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)
> + client->irq = stk8ba50_gpio_probe(client);
> +
> + 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_power_off;
> + 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;
> @@ -290,10 +515,16 @@ err_power_off:
> 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);
>
> - return stk8ba50_set_power(iio_priv(indio_dev), STK8BA50_MODE_SUSPEND);
> + if (data->dready_trig) {
> + iio_triggered_buffer_cleanup(indio_dev);
> + iio_trigger_unregister(data->dready_trig);
> + }
> +
> + return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
> }
>
> #ifdef CONFIG_PM_SLEEP
>
--
Peter Meerwald
+43-664-2444418 (mobile)
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