--- /dev/null
+/*
+ * 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");
projects / linux.git / commitdiff