Re: [PATCH v3] iio: adc: Add TI ADS1015 ADC driver support

[Michael Welling]

On Wed, Feb 03, 2016 at 06:59:56PM +0200, Daniel Baluta wrote:
> The driver has sysfs readings with runtime PM support for power saving.
> It also offers buffer support that can be used together with IIO software
> triggers.
> 
> Datasheet can be found here:
> 	http://www.ti.com.cn/cn/lit/ds/symlink/ads1015.pdf
> 
> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
> ---
> Changes since v2:
> 	* push locking out of the switch in write_raw
> 	* fix  buf allocation in triggered buffer's handler
> 
> Changes since v1:
> 	* addressed concerns about replacing the ads1015 hwmon driver
> 		* For the moment the IIO driver is compatible with hwmon
> 		  driver (dt bindings) the only thing left is to also add
> 		  support for ads1115.
> 		* DT bindings are described in Documentation/devicetree/
> 		  bindings/hwmon/ads1015.txt. If needed will copy this file
> 		  in a later patch to the IIO corresponding location.
> 	* addressed comments from Jonathan
> 		* added proper locking
> 		* added timestamp channel
> 		* removed magic constants
> 		* added some new lines to increase readability
> 		* used regmap_get_device instead of keeping a copy of
> 		i2c_client pointer.
> 		* used non-devm function to correct the cleanup order
> 
>  drivers/iio/adc/Kconfig      |  13 +
>  drivers/iio/adc/Makefile     |   1 +
>  drivers/iio/adc/ti-ads1015.c | 616 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 630 insertions(+)
>  create mode 100644 drivers/iio/adc/ti-ads1015.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 60673b4..fad7e6a 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -370,6 +370,19 @@ config TI_ADC128S052
>  	  This driver can also be built as a module. If so, the module will be
>  	  called ti-adc128s052.
>  
> +config TI_ADS1015
> +	tristate "Texas Instruments ADS1015 ADC"
> +	depends on I2C && !SENSORS_ADS1015
> +	select REGMAP_I2C
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	help
> +	  If you say yes here you get support for Texas Instruments ADS1015
> +	  ADC chip.
> +
> +	  This driver can also be built as a module. If so, the module will be
> +	  called ti-ads1015.
> +
>  config TI_ADS8688
>  	tristate "Texas Instruments ADS8688"
>  	depends on SPI && OF
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index fb57e12..2ff70a3 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -36,6 +36,7 @@ obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
>  obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
>  obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
>  obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
> +obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
>  obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
>  obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
>  obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
> diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
> new file mode 100644
> index 0000000..abe78d3
> --- /dev/null
> +++ b/drivers/iio/adc/ti-ads1015.c
> @@ -0,0 +1,616 @@
> +/*
> + * ADS1015 - Texas Instruments Analog-to-Digital Converter
> + *
> + * Copyright (c) 2016, 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 ADS1015 ADC 7-bit I2C slave address:
> + *	* 0x48 - ADDR connectd to Ground
> + *	* 0x49 - ADDR connected to Vdd
> + *	* 0x4A - ADDR connected to SDA
> + *	* 0x4B - ADDR connected to SCL
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/mutex.h>
> +#include <linux/delay.h>
> +
> +#include <linux/i2c/ads1015.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/types.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +
> +#define ADS1015_DRV_NAME "ads1015"
> +
> +#define ADS1015_CONV_REG	0x00
> +#define ADS1015_CFG_REG		0x01
> +
> +#define ADS1015_CFG_DR_SHIFT	5
> +#define ADS1015_CFG_MOD_SHIFT	8
> +#define ADS1015_CFG_PGA_SHIFT	9
> +#define ADS1015_CFG_MUX_SHIFT	12
> +
> +#define ADS1015_CFG_DR_MASK	GENMASK(7, 5)
> +#define ADS1015_CFG_MOD_MASK	BIT(8)
> +#define ADS1015_CFG_PGA_MASK	GENMASK(11, 9)
> +#define ADS1015_CFG_MUX_MASK	GENMASK(14, 12)
> +
> +/* device operating modes */
> +#define ADS1015_CONTINUOUS	0
> +#define ADS1015_SINGLESHOT	1
> +
> +#define ADS1015_SLEEP_DELAY_MS		2000
> +#define ADS1015_DEFAULT_PGA		2
> +#define ADS1015_DEFAULT_DATA_RATE	4
> +#define ADS1015_DEFAULT_CHAN		0
> +
> +enum ads1015_channels {
> +	ADS1015_AIN0_AIN1 = 0,
> +	ADS1015_AIN0_AIN3,
> +	ADS1015_AIN1_AIN3,
> +	ADS1015_AIN2_AIN3,
> +	ADS1015_AIN0,
> +	ADS1015_AIN1,
> +	ADS1015_AIN2,
> +	ADS1015_AIN3,
> +	ADS1015_TIMESTAMP,
> +};
> +
> +static const unsigned int ads1015_data_rate[] = {
> +	128, 250, 490, 920, 1600, 2400, 3300, 3300
> +};
> +
> +static const struct {
> +	int scale;
> +	int uscale;
> +} ads1015_scale[] = {
> +	{3, 0},
> +	{2, 0},
> +	{1, 0},
> +	{0, 500000},
> +	{0, 250000},
> +	{0, 125000},
> +	{0, 125000},
> +	{0, 125000},
> +};
> +
> +#define ADS1015_V_CHAN(_chan, _addr) {				\
> +	.type = IIO_VOLTAGE,					\
> +	.indexed = 1,						\
> +	.address = _addr,					\
> +	.channel = _chan,					\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
> +				BIT(IIO_CHAN_INFO_SCALE) |	\
> +				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
> +	.scan_index = _addr,					\
> +	.scan_type = {						\
> +		.sign = 's',					\
> +		.realbits = 12,					\
> +		.storagebits = 16,				\
> +		.shift = 4,					\
> +		.endianness = IIO_CPU,				\
> +	},							\
> +}
> +
> +#define ADS1015_V_DIFF_CHAN(_chan, _chan2, _addr) {		\
> +	.type = IIO_VOLTAGE,					\
> +	.differential = 1,					\
> +	.indexed = 1,						\
> +	.address = _addr,					\
> +	.channel = _chan,					\
> +	.channel2 = _chan2,					\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
> +				BIT(IIO_CHAN_INFO_SCALE) |	\
> +				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
> +	.scan_index = _addr,					\
> +	.scan_type = {						\
> +		.sign = 's',					\
> +		.realbits = 12,					\
> +		.storagebits = 16,				\
> +		.shift = 4,					\
> +		.endianness = IIO_CPU,				\
> +	},							\
> +}
> +
> +struct ads1015_data {
> +	struct regmap *regmap;
> +	/*
> +	 * Protects ADC ops, e.g: concurrent sysfs/buffered
> +	 * data reads, configuration updates
> +	 */
> +	struct mutex lock;
> +	struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
> +};
> +
> +static bool ads1015_is_writeable_reg(struct device *dev, unsigned int reg)
> +{
> +	return (reg == ADS1015_CFG_REG);
> +}
> +
> +static const struct regmap_config ads1015_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 16,
> +	.max_register = ADS1015_CFG_REG,
> +	.writeable_reg = ads1015_is_writeable_reg,
> +};
> +
> +static const struct iio_chan_spec ads1015_channels[] = {
> +	ADS1015_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
> +	ADS1015_V_DIFF_CHAN(0, 3, ADS1015_AIN0_AIN3),
> +	ADS1015_V_DIFF_CHAN(1, 3, ADS1015_AIN1_AIN3),
> +	ADS1015_V_DIFF_CHAN(2, 3, ADS1015_AIN2_AIN3),
> +	ADS1015_V_CHAN(0, ADS1015_AIN0),
> +	ADS1015_V_CHAN(1, ADS1015_AIN1),
> +	ADS1015_V_CHAN(2, ADS1015_AIN2),
> +	ADS1015_V_CHAN(3, ADS1015_AIN3),
> +	IIO_CHAN_SOFT_TIMESTAMP(ADS1015_TIMESTAMP),
> +};
> +
> +static int ads1015_set_power_state(struct ads1015_data *data, bool on)
> +{
> +	int ret;
> +	struct device *dev = regmap_get_device(data->regmap);
> +
> +	if (on) {
> +		ret = pm_runtime_get_sync(dev);
> +		if (ret < 0)
> +			pm_runtime_put_noidle(dev);
> +	} else {
> +		pm_runtime_mark_last_busy(dev);
> +		ret = pm_runtime_put_autosuspend(dev);
> +	}
> +
> +	return ret;
> +}
> +
> +static
> +int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
> +{
> +	int ret, pga, dr, conv_time;
> +	bool change;
> +
> +	if (chan < 0 || chan >= ADS1015_CHANNELS)
> +		return -EINVAL;
> +
> +	pga = data->channel_data[chan].pga;
> +	dr = data->channel_data[chan].data_rate;
> +
> +	ret = regmap_update_bits_check(data->regmap, ADS1015_CFG_REG,
> +				       ADS1015_CFG_MUX_MASK |
> +				       ADS1015_CFG_PGA_MASK,
> +				       chan << ADS1015_CFG_MUX_SHIFT |
> +				       pga << ADS1015_CFG_PGA_SHIFT,
> +				       &change);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (change) {
> +		conv_time = DIV_ROUND_UP(USEC_PER_SEC, ads1015_data_rate[dr]);
> +		usleep_range(conv_time, conv_time + 1);
> +	}
> +
> +	return regmap_read(data->regmap, ADS1015_CONV_REG, val);
> +}
> +
> +static irqreturn_t ads1015_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct ads1015_data *data = iio_priv(indio_dev);
> +	s16 buf[8]; /* 1x s16 ADC val + 3x s16 padding +  4x s16 timestamp */
> +	int chan, ret, res;
> +
> +	memset(buf, 0, sizeof(buf));
> +
> +	mutex_lock(&data->lock);
> +	chan = find_first_bit(indio_dev->active_scan_mask,
> +			      indio_dev->masklength);
> +	ret = ads1015_get_adc_result(data, chan, &res);
> +	if (ret < 0) {
> +		mutex_unlock(&data->lock);
> +		goto err;
> +	}
> +
> +	buf[0] = res;
> +	mutex_unlock(&data->lock);
> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());
> +
> +err:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int ads1015_set_scale(struct ads1015_data *data, int chan,
> +			     int scale, int uscale)
> +{
> +	int i, ret, rindex = -1;
> +
> +	for (i = 0; i < ARRAY_SIZE(ads1015_scale); i++)
> +		if (ads1015_scale[i].scale == scale &&
> +		    ads1015_scale[i].uscale == uscale) {
> +			rindex = i;
> +			break;
> +		}
> +	if (rindex < 0)
> +		return -EINVAL;
> +
> +	ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
> +				 ADS1015_CFG_PGA_MASK,
> +				 rindex << ADS1015_CFG_PGA_SHIFT);
> +	if (ret < 0)
> +		return ret;
> +
> +	data->channel_data[chan].pga = rindex;
> +
> +	return 0;
> +}
> +
> +static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate)
> +{
> +	int i, ret, rindex = -1;
> +
> +	for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++)
> +		if (ads1015_data_rate[i] == rate) {
> +			rindex = i;
> +			break;
> +		}
> +	if (rindex < 0)
> +		return -EINVAL;
> +
> +	ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
> +				 ADS1015_CFG_DR_MASK,
> +				 rindex << ADS1015_CFG_DR_SHIFT);
> +	if (ret < 0)
> +		return ret;
> +
> +	data->channel_data[chan].data_rate = rindex;
> +
> +	return 0;
> +}
> +
> +static int ads1015_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan, int *val,
> +			    int *val2, long mask)
> +{
> +	int ret, idx;
> +	struct ads1015_data *data = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&data->lock);
> +		if (iio_buffer_enabled(indio_dev)) {
> +			mutex_unlock(&data->lock);
> +			return -EBUSY;
> +		}
> +
> +		ret = ads1015_set_power_state(data, true);
> +		if (ret < 0) {
> +			mutex_unlock(&data->lock);
> +			return ret;
> +		}
> +
> +		ret = ads1015_get_adc_result(data, chan->address, val);
> +		if (ret < 0) {
> +			ads1015_set_power_state(data, false);
> +			mutex_unlock(&data->lock);
> +			return ret;
> +		}
> +
> +		/* 12 bit res, D0 is bit 4 in conversion register */
> +		*val = sign_extend32(*val >> 4, 11);
> +
> +		ret = ads1015_set_power_state(data, false);
> +		mutex_unlock(&data->lock);
> +
> +		if (ret < 0)
> +			return ret;
> +
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		mutex_lock(&data->lock);
> +		idx = data->channel_data[chan->address].pga;
> +		*val = ads1015_scale[idx].scale;
> +		*val2 = ads1015_scale[idx].uscale;
> +		mutex_unlock(&data->lock);
> +
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		mutex_lock(&data->lock);
> +		idx = data->channel_data[chan->address].data_rate;
> +		*val = ads1015_data_rate[idx];
> +		mutex_unlock(&data->lock);
> +
> +		return IIO_VAL_INT;
> +	default:
> +		break;
> +	}
> +
> +	return -EINVAL;
> +}

Would it be more consistent to handle the mutex outside of the switch above similar
to how it is handled in ads1015_write_raw?

Also the ads1015_set_power_state(data, false) is called either way so why not just
use one call?

IE:
static int ads1015_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan, int *val,
			    int *val2, long mask)
{
	int ret, ret1, idx;
	struct ads1015_data *data = iio_priv(indio_dev);

	mutex_lock(&data->lock);
	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		if (iio_buffer_enabled(indio_dev)) {
			ret = -EBUSY;
			break;
		}

		ret = ads1015_set_power_state(data, true);
		if (ret < 0)
			break;

		ret = ads1015_get_adc_result(data, chan->address, val);
		if (!ret) {
			/* 12 bit res, D0 is bit 4 in conversion register */
			*val = sign_extend32(*val >> 4, 11);
			ret = IIO_VAL_INT;
		}

		ret1 = ads1015_set_power_state(data, false);
		if (ret1 < 0)
			ret = ret1;

		break;
	case IIO_CHAN_INFO_SCALE:
		idx = data->channel_data[chan->address].pga;
		*val = ads1015_scale[idx].scale;
		*val2 = ads1015_scale[idx].uscale;
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;
	case IIO_CHAN_INFO_SAMP_FREQ:
		idx = data->channel_data[chan->address].data_rate;
		*val = ads1015_data_rate[idx];
		ret = IIO_VAL_INT;
		break;
	default:
		ret = -EINVAL;
		break;
	}
	mutex_unlock(&data->lock);

	return ret;
}



> +
> +static int ads1015_write_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan, int val,
> +			     int val2, long mask)
> +{
> +	struct ads1015_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->lock);
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SCALE:
> +		ret = ads1015_set_scale(data, chan->address, val, val2);
> +		break;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret = ads1015_set_data_rate(data, chan->address, val);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +	mutex_unlock(&data->lock);
> +
> +	return ret;
> +}
> +
> +static int ads1015_buffer_preenable(struct iio_dev *indio_dev)
> +{
> +	return ads1015_set_power_state(iio_priv(indio_dev), true);
> +}
> +
> +static int ads1015_buffer_postdisable(struct iio_dev *indio_dev)
> +{
> +	return ads1015_set_power_state(iio_priv(indio_dev), false);
> +}
> +
> +static const struct iio_buffer_setup_ops ads1015_buffer_setup_ops = {
> +	.preenable	= ads1015_buffer_preenable,
> +	.postenable	= iio_triggered_buffer_postenable,
> +	.predisable	= iio_triggered_buffer_predisable,
> +	.postdisable	= ads1015_buffer_postdisable,
> +	.validate_scan_mask = &iio_validate_scan_mask_onehot,
> +};
> +
> +static IIO_CONST_ATTR(scale_available, "3 2 1 0.5 0.25 0.125");
> +static IIO_CONST_ATTR(sampling_frequency_available,
> +		      "128 250 490 920 1600 2400 3300");
> +
> +static struct attribute *ads1015_attributes[] = {
> +	&iio_const_attr_scale_available.dev_attr.attr,
> +	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group ads1015_attribute_group = {
> +	.attrs = ads1015_attributes,
> +};
> +
> +static const struct iio_info ads1015_info = {
> +	.driver_module	= THIS_MODULE,
> +	.read_raw	= ads1015_read_raw,
> +	.write_raw	= ads1015_write_raw,
> +	.attrs		= &ads1015_attribute_group,
> +};
> +
> +#ifdef CONFIG_OF
> +static int ads1015_get_channels_config_of(struct i2c_client *client)
> +{
> +	struct ads1015_data *data = i2c_get_clientdata(client);
> +	struct device_node *node;
> +
> +	if (!client->dev.of_node ||
> +	    !of_get_next_child(client->dev.of_node, NULL))
> +		return -EINVAL;
> +
> +	for_each_child_of_node(client->dev.of_node, node) {
> +		u32 pval;
> +		unsigned int channel;
> +		unsigned int pga = ADS1015_DEFAULT_PGA;
> +		unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
> +
> +		if (of_property_read_u32(node, "reg", &pval)) {
> +			dev_err(&client->dev, "invalid reg on %s\n",
> +				node->full_name);
> +			continue;
> +		}
> +
> +		channel = pval;
> +		if (channel >= ADS1015_CHANNELS) {
> +			dev_err(&client->dev,
> +				"invalid channel index %d on %s\n",
> +				channel, node->full_name);
> +			continue;
> +		}
> +
> +		if (!of_property_read_u32(node, "ti,gain", &pval)) {
> +			pga = pval;
> +			if (pga > 6) {
> +				dev_err(&client->dev, "invalid gain on %s\n",
> +					node->full_name);
> +				return -EINVAL;
> +			}
> +		}
> +
> +		if (!of_property_read_u32(node, "ti,datarate", &pval)) {
> +			data_rate = pval;
> +			if (data_rate > 7) {
> +				dev_err(&client->dev,
> +					"invalid data_rate on %s\n",
> +					node->full_name);
> +				return -EINVAL;
> +			}
> +		}
> +
> +		data->channel_data[channel].pga = pga;
> +		data->channel_data[channel].data_rate = data_rate;
> +	}
> +
> +	return 0;
> +}
> +#endif
> +
> +static void ads1015_get_channels_config(struct i2c_client *client)
> +{
> +	unsigned int k;
> +
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct ads1015_data *data = iio_priv(indio_dev);
> +	struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
> +
> +	/* prefer platform data */
> +	if (pdata) {
> +		memcpy(data->channel_data, pdata->channel_data,
> +		       sizeof(data->channel_data));
> +		return;
> +	}
> +
> +#ifdef CONFIG_OF
> +	if (!ads1015_get_channels_config_of(client))
> +		return;
> +#endif
> +	/* fallback on default configuration */
> +	for (k = 0; k < ADS1015_CHANNELS; ++k) {
> +		data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
> +		data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
> +	}
> +}
> +
> +static int ads1015_probe(struct i2c_client *client,
> +			 const struct i2c_device_id *id)
> +{
> +	struct iio_dev *indio_dev;
> +	struct ads1015_data *data;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	i2c_set_clientdata(client, indio_dev);
> +
> +	mutex_init(&data->lock);
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->info = &ads1015_info;
> +	indio_dev->name = ADS1015_DRV_NAME;
> +	indio_dev->channels = ads1015_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(ads1015_channels);
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	/* we need this be keep the same ABI with hwmon ADS1015 driver */
> +	ads1015_get_channels_config(client);
> +
> +	data->regmap = devm_regmap_init_i2c(client, &ads1015_regmap_config);
> +	if (IS_ERR(data->regmap)) {
> +		dev_err(&client->dev, "Failed to allocate register map\n");
> +		return PTR_ERR(data->regmap);
> +	}
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +					 ads1015_trigger_handler,
> +					 &ads1015_buffer_setup_ops);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "iio triggered buffer setup failed\n");
> +		return ret;
> +	}
> +	ret = pm_runtime_set_active(&client->dev);
> +	if (ret)
> +		goto err_buffer_cleanup;
> +	pm_runtime_set_autosuspend_delay(&client->dev, ADS1015_SLEEP_DELAY_MS);
> +	pm_runtime_use_autosuspend(&client->dev);
> +	pm_runtime_enable(&client->dev);
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "Failed to register IIO device\n");
> +		goto err_buffer_cleanup;
> +	}
> +
> +	return 0;
> +
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +
> +	return ret;
> +}
> +
> +static int ads1015_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct ads1015_data *data = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	pm_runtime_disable(&client->dev);
> +	pm_runtime_set_suspended(&client->dev);
> +	pm_runtime_put_noidle(&client->dev);
> +
> +	iio_triggered_buffer_cleanup(indio_dev);
> +
> +	/* power down single shot mode */
> +	return regmap_update_bits(data->regmap, ADS1015_CFG_REG,
> +				  ADS1015_CFG_MOD_MASK,
> +				  ADS1015_SINGLESHOT << ADS1015_CFG_MOD_SHIFT);
> +}
> +
> +#ifdef CONFIG_PM
> +static int ads1015_runtime_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct ads1015_data *data = iio_priv(indio_dev);
> +
> +	return regmap_update_bits(data->regmap, ADS1015_CFG_REG,
> +				  ADS1015_CFG_MOD_MASK,
> +				  ADS1015_SINGLESHOT << ADS1015_CFG_MOD_SHIFT);
> +}
> +
> +static int ads1015_runtime_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	struct ads1015_data *data = iio_priv(indio_dev);
> +
> +	return regmap_update_bits(data->regmap, ADS1015_CFG_REG,
> +				  ADS1015_CFG_MOD_MASK,
> +				  ADS1015_CONTINUOUS << ADS1015_CFG_MOD_SHIFT);
> +}
> +#endif
> +
> +static const struct dev_pm_ops ads1015_pm_ops = {
> +	SET_RUNTIME_PM_OPS(ads1015_runtime_suspend,
> +			   ads1015_runtime_resume, NULL)
> +};
> +
> +static const struct i2c_device_id ads1015_id[] = {
> +	{"ads1015", 0},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, ads1015_id);
> +
> +static struct i2c_driver ads1015_driver = {
> +	.driver = {
> +		.name = ADS1015_DRV_NAME,
> +		.pm = &ads1015_pm_ops,
> +	},
> +	.probe		= ads1015_probe,
> +	.remove		= ads1015_remove,
> +	.id_table	= ads1015_id,
> +};
> +
> +module_i2c_driver(ads1015_driver);
> +
> +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Texas Instruments ADS1015 ADC driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.5.0
>