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Date: Sat, 3 Sep 2016 20:37:27 +0100
From: Jonathan Cameron <jic23@...nel.org>
To: Alison Schofield <amsfield22@...il.com>
Cc: mranostay@...il.com, knaack.h@....de, lars@...afoo.de,
pmeerw@...erw.net, linux-iio@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4] iio: humidity: hdc100x: add triggered buffer support
for HDC100X
On 02/09/16 18:23, Alison Schofield wrote:
> Triggered buffer support uses the HDC100X's dual acquisition mode
> to read both humidity and temperature in one shot.
>
> This patch depends on
> 447136effbf4 ("iio: humidity: hdc100x: fix sensor data reads of
> temp and humidity")
>
> Signed-off-by: Alison Schofield <amsfield22@...il.com>
> Cc: Daniel Baluta <daniel.baluta@...il.com>
Looks good. I'll have to hold it until the dependency has worked it's way
into my togreg branch in a week or so.
Feel free to remind me!
Jonathan
> ---
>
> Changes in v4:
> - unlock private lock if claim_direct_mode fails (kbuild robot reported)
> - move unlock to err: out path in trigger handler (kbuild robot inspired)
>
> Changes in v3:
> Thanks for the review Jonathan
> - This patch now depends on
> 447136effbf4 ("iio: humidity: hdc100x: fix sensor data reads of temp
> and humidity")
> - remove i2c functionality check, done in dependent patch
> - remove unused define HDC100X_ALL_CHANNEL_MASK
> - define and use available_scan_masks to demux between temp &/or humid
> data in buffered mode
> - changed timestamp channel scan_index from 3 to 2.
> - put back private data lock in read_raw
> (we'll lock private data lock and claim_direct_mode on raw reads)
> - remove unneeded NULL parameters in iio_buffer_setup_ops
> - add private data lock on buffered read
> We are going to allow configuration changes while the sensor is in
> buffered mode. We need to allow the toggling of the Heater Enable bit
> because the heater only functions during measurements. The lock will
> ensure that the config change and buffer read transaction do not collide.
> - blank lines added for readability per reviewer
>
> Changes in v2:
> Thanks for the review Peter
> - switched endianness from IIO_CPU to IIO_BE
> - use only one buffer in the handler
> - simplify selection of temp &/or humidity to push to buffer
>
>
> drivers/iio/humidity/Kconfig | 2 +
> drivers/iio/humidity/hdc100x.c | 130 ++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 130 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/humidity/Kconfig b/drivers/iio/humidity/Kconfig
> index f155386..5a25569 100644
> --- a/drivers/iio/humidity/Kconfig
> +++ b/drivers/iio/humidity/Kconfig
> @@ -25,6 +25,8 @@ config DHT11
> config HDC100X
> tristate "TI HDC100x relative humidity and temperature sensor"
> depends on I2C
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> help
> Say yes here to build support for the Texas Instruments
> HDC1000 and HDC1008 relative humidity and temperature sensors.
> diff --git a/drivers/iio/humidity/hdc100x.c b/drivers/iio/humidity/hdc100x.c
> index e0c9c70..265c34d 100644
> --- a/drivers/iio/humidity/hdc100x.c
> +++ b/drivers/iio/humidity/hdc100x.c
> @@ -22,11 +22,15 @@
>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
>
> #define HDC100X_REG_TEMP 0x00
> #define HDC100X_REG_HUMIDITY 0x01
>
> #define HDC100X_REG_CONFIG 0x02
> +#define HDC100X_REG_CONFIG_ACQ_MODE BIT(12)
> #define HDC100X_REG_CONFIG_HEATER_EN BIT(13)
>
> struct hdc100x_data {
> @@ -87,22 +91,40 @@ static const struct iio_chan_spec hdc100x_channels[] = {
> BIT(IIO_CHAN_INFO_SCALE) |
> BIT(IIO_CHAN_INFO_INT_TIME) |
> BIT(IIO_CHAN_INFO_OFFSET),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 's',
> + .realbits = 16,
> + .storagebits = 16,
> + .endianness = IIO_BE,
> + },
> },
> {
> .type = IIO_HUMIDITYRELATIVE,
> .address = HDC100X_REG_HUMIDITY,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> BIT(IIO_CHAN_INFO_SCALE) |
> - BIT(IIO_CHAN_INFO_INT_TIME)
> + BIT(IIO_CHAN_INFO_INT_TIME),
> + .scan_index = 1,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 16,
> + .storagebits = 16,
> + .endianness = IIO_BE,
> + },
> },
> {
> .type = IIO_CURRENT,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> .extend_name = "heater",
> .output = 1,
> + .scan_index = -1,
> },
> + IIO_CHAN_SOFT_TIMESTAMP(2),
> };
>
> +static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
> +
> static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
> {
> int tmp = (~mask & data->config) | val;
> @@ -183,7 +205,14 @@ static int hdc100x_read_raw(struct iio_dev *indio_dev,
> *val = hdc100x_get_heater_status(data);
> ret = IIO_VAL_INT;
> } else {
> + ret = iio_device_claim_direct_mode(indio_dev);
> + if (ret) {
> + mutex_unlock(&data->lock);
> + return ret;
> + }
> +
> ret = hdc100x_get_measurement(data, chan);
> + iio_device_release_direct_mode(indio_dev);
> if (ret >= 0) {
> *val = ret;
> ret = IIO_VAL_INT;
> @@ -246,6 +275,78 @@ static int hdc100x_write_raw(struct iio_dev *indio_dev,
> }
> }
>
> +static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
> +{
> + struct hdc100x_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + /* Buffer is enabled. First set ACQ Mode, then attach poll func */
> + mutex_lock(&data->lock);
> + ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
> + HDC100X_REG_CONFIG_ACQ_MODE);
> + mutex_unlock(&data->lock);
> + if (ret)
> + return ret;
> +
> + return iio_triggered_buffer_postenable(indio_dev);
> +}
> +
> +static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
> +{
> + struct hdc100x_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + /* First detach poll func, then reset ACQ mode. OK to disable buffer */
> + ret = iio_triggered_buffer_predisable(indio_dev);
> + if (ret)
> + return ret;
> +
> + mutex_lock(&data->lock);
> + ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
> + mutex_unlock(&data->lock);
> +
> + return ret;
> +}
> +
> +static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
> + .postenable = hdc100x_buffer_postenable,
> + .predisable = hdc100x_buffer_predisable,
> +};
> +
> +static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct hdc100x_data *data = iio_priv(indio_dev);
> + struct i2c_client *client = data->client;
> + int delay = data->adc_int_us[0] + data->adc_int_us[1];
> + int ret;
> + s16 buf[8]; /* 2x s16 + padding + 8 byte timestamp */
> +
> + /* dual read starts at temp register */
> + mutex_lock(&data->lock);
> + ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
> + if (ret < 0) {
> + dev_err(&client->dev, "cannot start measurement\n");
> + goto err;
> + }
> + usleep_range(delay, delay + 1000);
> +
> + ret = i2c_master_recv(client, (u8 *)buf, 4);
> + if (ret < 0) {
> + dev_err(&client->dev, "cannot read sensor data\n");
> + goto err;
> + }
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, buf,
> + iio_get_time_ns(indio_dev));
> +err:
> + mutex_unlock(&data->lock);
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> static const struct iio_info hdc100x_info = {
> .read_raw = hdc100x_read_raw,
> .write_raw = hdc100x_write_raw,
> @@ -258,6 +359,7 @@ static int hdc100x_probe(struct i2c_client *client,
> {
> struct iio_dev *indio_dev;
> struct hdc100x_data *data;
> + int ret;
>
> if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
> I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
> @@ -279,12 +381,35 @@ static int hdc100x_probe(struct i2c_client *client,
>
> indio_dev->channels = hdc100x_channels;
> indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
> + indio_dev->available_scan_masks = hdc100x_scan_masks;
>
> /* be sure we are in a known state */
> hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
> hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
> + hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
> +
> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
> + hdc100x_trigger_handler,
> + &hdc_buffer_setup_ops);
> + if (ret < 0) {
> + dev_err(&client->dev, "iio triggered buffer setup failed\n");
> + return ret;
> + }
> + ret = iio_device_register(indio_dev);
> + if (ret < 0)
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + return ret;
> +}
> +
> +static int hdc100x_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + iio_device_unregister(indio_dev);
> + iio_triggered_buffer_cleanup(indio_dev);
>
> - return devm_iio_device_register(&client->dev, indio_dev);
> + return 0;
> }
>
> static const struct i2c_device_id hdc100x_id[] = {
> @@ -298,6 +423,7 @@ static struct i2c_driver hdc100x_driver = {
> .name = "hdc100x",
> },
> .probe = hdc100x_probe,
> + .remove = hdc100x_remove,
> .id_table = hdc100x_id,
> };
> module_i2c_driver(hdc100x_driver);
>
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