--- /dev/null
+/*
+ * ltr501.c - Support for Lite-On LTR501 ambient light and proximity sensor
+ *
+ * Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
+ *
+ * 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.
+ *
+ * 7-bit I2C slave address 0x23
+ *
+ * TODO: interrupt, threshold, measurement rate, IR LED characteristics
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define LTR501_DRV_NAME "ltr501"
+
+#define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
+#define LTR501_PS_CONTR 0x81 /* PS operation mode */
+#define LTR501_PART_ID 0x86
+#define LTR501_MANUFAC_ID 0x87
+#define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */
+#define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
+#define LTR501_ALS_PS_STATUS 0x8c
+#define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
+
+#define LTR501_ALS_CONTR_SW_RESET BIT(2)
+#define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))
+#define LTR501_CONTR_PS_GAIN_SHIFT 2
+#define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
+#define LTR501_CONTR_ACTIVE BIT(1)
+
+#define LTR501_STATUS_ALS_RDY BIT(2)
+#define LTR501_STATUS_PS_RDY BIT(0)
+
+#define LTR501_PS_DATA_MASK 0x7ff
+
+struct ltr501_data {
+ struct i2c_client *client;
+ struct mutex lock_als, lock_ps;
+ u8 als_contr, ps_contr;
+};
+
+static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
+{
+ int tries = 100;
+ int ret;
+
+ while (tries--) {
+ ret = i2c_smbus_read_byte_data(data->client,
+ LTR501_ALS_PS_STATUS);
+ if (ret < 0)
+ return ret;
+ if ((ret & drdy_mask) == drdy_mask)
+ return 0;
+ msleep(25);
+ }
+
+ dev_err(&data->client->dev, "ltr501_drdy() failed, data not ready\n");
+ return -EIO;
+}
+
+static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
+{
+ int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
+ if (ret < 0)
+ return ret;
+ /* always read both ALS channels in given order */
+ return i2c_smbus_read_i2c_block_data(data->client,
+ LTR501_ALS_DATA1, 2 * sizeof(__le16), (u8 *) buf);
+}
+
+static int ltr501_read_ps(struct ltr501_data *data)
+{
+ int ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
+ if (ret < 0)
+ return ret;
+ return i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
+}
+
+#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \
+ .type = IIO_INTENSITY, \
+ .modified = 1, \
+ .address = (_addr), \
+ .channel2 = (_mod), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = (_shared), \
+ .scan_index = (_idx), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_CPU, \
+ } \
+}
+
+static const struct iio_chan_spec ltr501_channels[] = {
+ LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
+ LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
+ BIT(IIO_CHAN_INFO_SCALE)),
+ {
+ .type = IIO_PROXIMITY,
+ .address = LTR501_PS_DATA,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 2,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 11,
+ .storagebits = 16,
+ .endianness = IIO_CPU,
+ },
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static const int ltr501_ps_gain[4][2] = {
+ {1, 0}, {0, 250000}, {0, 125000}, {0, 62500}
+};
+
+static int ltr501_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct ltr501_data *data = iio_priv(indio_dev);
+ __le16 buf[2];
+ int ret, i;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ if (iio_buffer_enabled(indio_dev))
+ return -EBUSY;
+
+ switch (chan->type) {
+ case IIO_INTENSITY:
+ mutex_lock(&data->lock_als);
+ ret = ltr501_read_als(data, buf);
+ mutex_unlock(&data->lock_als);
+ if (ret < 0)
+ return ret;
+ *val = le16_to_cpu(chan->address == LTR501_ALS_DATA1 ?
+ buf[0] : buf[1]);
+ return IIO_VAL_INT;
+ case IIO_PROXIMITY:
+ mutex_lock(&data->lock_ps);
+ ret = ltr501_read_ps(data);
+ mutex_unlock(&data->lock_ps);
+ if (ret < 0)
+ return ret;
+ *val = ret & LTR501_PS_DATA_MASK;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_INTENSITY:
+ if (data->als_contr & LTR501_CONTR_ALS_GAIN_MASK) {
+ *val = 0;
+ *val2 = 5000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ } else {
+ *val = 1;
+ *val2 = 0;
+ return IIO_VAL_INT;
+ }
+ case IIO_PROXIMITY:
+ i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
+ LTR501_CONTR_PS_GAIN_SHIFT;
+ *val = ltr501_ps_gain[i][0];
+ *val2 = ltr501_ps_gain[i][1];
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+ }
+ return -EINVAL;
+}
+
+static int ltr501_get_ps_gain_index(int val, int val2)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ltr501_ps_gain); i++)
+ if (val == ltr501_ps_gain[i][0] && val2 == ltr501_ps_gain[i][1])
+ return i;
+
+ return -1;
+}
+
+static int ltr501_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct ltr501_data *data = iio_priv(indio_dev);
+ int i;
+
+ if (iio_buffer_enabled(indio_dev))
+ return -EBUSY;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->type) {
+ case IIO_INTENSITY:
+ if (val == 0 && val2 == 5000)
+ data->als_contr |= LTR501_CONTR_ALS_GAIN_MASK;
+ else if (val == 1 && val2 == 0)
+ data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;
+ else
+ return -EINVAL;
+ return i2c_smbus_write_byte_data(data->client,
+ LTR501_ALS_CONTR, data->als_contr);
+ case IIO_PROXIMITY:
+ i = ltr501_get_ps_gain_index(val, val2);
+ if (i < 0)
+ return -EINVAL;
+ data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
+ data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;
+ return i2c_smbus_write_byte_data(data->client,
+ LTR501_PS_CONTR, data->ps_contr);
+ default:
+ return -EINVAL;
+ }
+ }
+ return -EINVAL;
+}
+
+static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
+static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
+
+static struct attribute *ltr501_attributes[] = {
+ &iio_const_attr_in_proximity_scale_available.dev_attr.attr,
+ &iio_const_attr_in_intensity_scale_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group ltr501_attribute_group = {
+ .attrs = ltr501_attributes,
+};
+
+static const struct iio_info ltr501_info = {
+ .read_raw = ltr501_read_raw,
+ .write_raw = ltr501_write_raw,
+ .attrs = <r501_attribute_group,
+ .driver_module = THIS_MODULE,
+};
+
+static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)
+{
+ int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);
+ if (ret < 0)
+ return ret;
+
+ return i2c_smbus_write_byte_data(client, LTR501_PS_CONTR, ps_val);
+}
+
+static irqreturn_t ltr501_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ltr501_data *data = iio_priv(indio_dev);
+ u16 buf[8];
+ __le16 als_buf[2];
+ u8 mask = 0;
+ int j = 0;
+ int ret;
+
+ memset(buf, 0, sizeof(buf));
+
+ /* figure out which data needs to be ready */
+ if (test_bit(0, indio_dev->active_scan_mask) ||
+ test_bit(1, indio_dev->active_scan_mask))
+ mask |= LTR501_STATUS_ALS_RDY;
+ if (test_bit(2, indio_dev->active_scan_mask))
+ mask |= LTR501_STATUS_PS_RDY;
+
+ ret = ltr501_drdy(data, mask);
+ if (ret < 0)
+ goto done;
+
+ if (mask & LTR501_STATUS_ALS_RDY) {
+ ret = i2c_smbus_read_i2c_block_data(data->client,
+ LTR501_ALS_DATA1, sizeof(als_buf), (u8 *) als_buf);
+ if (ret < 0)
+ return ret;
+ if (test_bit(0, indio_dev->active_scan_mask))
+ buf[j++] = le16_to_cpu(als_buf[1]);
+ if (test_bit(1, indio_dev->active_scan_mask))
+ buf[j++] = le16_to_cpu(als_buf[0]);
+ }
+
+ if (mask & LTR501_STATUS_PS_RDY) {
+ ret = i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
+ if (ret < 0)
+ goto done;
+ buf[j++] = ret & LTR501_PS_DATA_MASK;
+ }
+
+ iio_push_to_buffers_with_timestamp(indio_dev, buf,
+ iio_get_time_ns());
+
+done:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int ltr501_init(struct ltr501_data *data)
+{
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);
+ if (ret < 0)
+ return ret;
+ data->als_contr = ret | LTR501_CONTR_ACTIVE;
+
+ ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);
+ if (ret < 0)
+ return ret;
+ data->ps_contr = ret | LTR501_CONTR_ACTIVE;
+
+ return ltr501_write_contr(data->client, data->als_contr,
+ data->ps_contr);
+}
+
+static int ltr501_powerdown(struct ltr501_data *data)
+{
+ return ltr501_write_contr(data->client,
+ data->als_contr & ~LTR501_CONTR_ACTIVE,
+ data->ps_contr & ~LTR501_CONTR_ACTIVE);
+}
+
+static int ltr501_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct ltr501_data *data;
+ struct iio_dev *indio_dev;
+ 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);
+ data->client = client;
+ mutex_init(&data->lock_als);
+ mutex_init(&data->lock_ps);
+
+ ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);
+ if (ret < 0)
+ return ret;
+ if ((ret >> 4) != 0x8)
+ return -ENODEV;
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = <r501_info;
+ indio_dev->channels = ltr501_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
+ indio_dev->name = LTR501_DRV_NAME;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = ltr501_init(data);
+ if (ret < 0)
+ return ret;
+
+ ret = iio_triggered_buffer_setup(indio_dev, NULL,
+ ltr501_trigger_handler, NULL);
+ if (ret)
+ goto powerdown_on_error;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto error_unreg_buffer;
+
+ return 0;
+
+error_unreg_buffer:
+ iio_triggered_buffer_cleanup(indio_dev);
+powerdown_on_error:
+ ltr501_powerdown(data);
+ return ret;
+}
+
+static int ltr501_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);
+ ltr501_powerdown(iio_priv(indio_dev));
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int ltr501_suspend(struct device *dev)
+{
+ struct ltr501_data *data = iio_priv(i2c_get_clientdata(
+ to_i2c_client(dev)));
+ return ltr501_powerdown(data);
+}
+
+static int ltr501_resume(struct device *dev)
+{
+ struct ltr501_data *data = iio_priv(i2c_get_clientdata(
+ to_i2c_client(dev)));
+
+ return ltr501_write_contr(data->client, data->als_contr,
+ data->ps_contr);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);
+
+static const struct i2c_device_id ltr501_id[] = {
+ { "ltr501", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ltr501_id);
+
+static struct i2c_driver ltr501_driver = {
+ .driver = {
+ .name = LTR501_DRV_NAME,
+ .pm = <r501_pm_ops,
+ .owner = THIS_MODULE,
+ },
+ .probe = ltr501_probe,
+ .remove = ltr501_remove,
+ .id_table = ltr501_id,
+};
+
+module_i2c_driver(ltr501_driver);
+
+MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
+MODULE_DESCRIPTION("Lite-On LTR501 ambient light and proximity sensor driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff