Linux-libre 4.6.2-gnu

1 files changed, 612 insertions, 0 deletions

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
new file mode 100644
index 000000000..73cbf0b54
--- /dev/null
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -0,0 +1,612 @@
+/*
+ * 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 connected 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);
+
+	mutex_lock(&indio_dev->mlock);
+	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 < 0) {
+			ads1015_set_power_state(data, false);
+			break;
+		}
+
+		/* 12 bit res, D0 is bit 4 in conversion register */
+		*val = sign_extend32(*val >> 4, 11);
+
+		ret = ads1015_set_power_state(data, false);
+		if (ret < 0)
+			break;
+
+		ret = IIO_VAL_INT;
+		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);
+	mutex_unlock(&indio_dev->mlock);
+
+	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 to keep this ABI the same as used by 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@intel.com>");
+MODULE_DESCRIPTION("Texas Instruments ADS1015 ADC driver");
+MODULE_LICENSE("GPL v2");