Minimal implementation of an IIO driver for the Sensortek
STK3310 ambient light and proximity sensor. The STK3311
model is also supported.
Includes:
- ACPI support;
- read_raw and write_raw;
- reading and setting configuration parameters for gain/scale
and integration time for both ALS and PS.
Signed-off-by: Tiberiu Breana <tiberiu.a.breana@xxxxxxxxx>
---
drivers/iio/light/Kconfig | 11 +
drivers/iio/light/Makefile | 1 +
drivers/iio/light/stk3310.c | 492 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 504 insertions(+)
create mode 100644 drivers/iio/light/stk3310.c
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 01a1a16..096129d 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -174,6 +174,17 @@ config LTR501
This driver can also be built as a module. If so, the module
will be called ltr501.
+config STK3310
+ tristate "STK3310 ALS and proximity sensor"
+ depends on I2C
+ help
+ Say yes here to get support for the Sensortek STK3310 ambient light
+ and proximity sensor. The STK3311 model is also supported by this
+ driver.
+
+ Choosing M will build the driver as a module. If so, the module
+ will be called stk3310.
+
config TCS3414
tristate "TAOS TCS3414 digital color sensor"
depends on I2C
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index ad7c30f..90e7fd2 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_JSA1212) += jsa1212.o
obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o
obj-$(CONFIG_LTR501) += ltr501.o
obj-$(CONFIG_SENSORS_TSL2563) += tsl2563.o
+obj-$(CONFIG_STK3310) += stk3310.o
obj-$(CONFIG_TCS3414) += tcs3414.o
obj-$(CONFIG_TCS3472) += tcs3472.o
obj-$(CONFIG_TSL4531) += tsl4531.o
diff --git a/drivers/iio/light/stk3310.c b/drivers/iio/light/stk3310.c
new file mode 100644
index 0000000..5bcf5a0
--- /dev/null
+++ b/drivers/iio/light/stk3310.c
@@ -0,0 +1,492 @@
+/**
+ * Sensortek STK3310/STK3311 Ambient Light and Proximity Sensor
+ *
+ * Copyright (c) 2015, 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 STK3310/STK3311. 7-bit I2C address: 0x48.
+ */
+
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define STK3310_REG_STATE 0x00
+#define STK3310_REG_PSCTRL 0x01
+#define STK3310_REG_ALSCTRL 0x02
+#define STK3310_REG_PS_DATA_MSB 0x11
+#define STK3310_REG_ALS_DATA_MSB 0x13
+#define STK3310_REG_PDT_ID 0x3E
+
+#define STK3310_STATE_EN_PS 0x01
+#define STK3310_STATE_EN_ALS 0x02
+#define STK3310_STATE_STANDBY 0x00
+#define STK3310_STATE_MASK 0x07
+
+#define STK3310_GAIN_MASK 0x30
+#define STK3310_IT_MASK 0x0F
+#define STK3310_GAIN_SHIFT 4
+#define STK3310_IT_SHIFT 0
+
+#define STK3310_CHIP_ID_VAL 0x13
+#define STK3311_CHIP_ID_VAL 0x1D
+
+#define STK3310_GAIN_MAX 3
+#define STK3310_IT_MAX 15
+#define STK3310_PS_MAX_VAL 0xffff
+
+#define STK3310_SCALE_AVAILABLE "6.4 1.6 0.4 0.1"
+
+#define STK3310_DRIVER_NAME "stk3310"
+
+/*
+ * Maximum PS values with regard to scale. Used to export the 'inverse'
+ * PS value (high values for far objects, low values for near objects).
+ */
+static const int stk3310_ps_max[4] = {
+ STK3310_PS_MAX_VAL / 64,
+ STK3310_PS_MAX_VAL / 16,
+ STK3310_PS_MAX_VAL / 4,
+ STK3310_PS_MAX_VAL,
+};
+
+static const int stk3310_scale_table[][2] = {
+ {6, 400000}, {1, 600000}, {0, 400000}, {0, 100000}
+};
+
+/* Integration time in seconds, microseconds */
+static const int stk3310_it_table[][2] = {
+ {0, 185000}, {0, 370000}, {0, 741000}, {0, 148000},
+ {0, 296000}, {0, 592000}, {0, 118400}, {0, 236800},
+ {0, 473600}, {0, 947200}, {0, 189440}, {0, 378880},
+ {0, 757760}, {1, 515520}, {3, 31040}, {6, 62080},
+};
+
+enum stk3310_data_type {
+ STK3310_ALS,
+ STK3310_PS
+};
+
+enum stk3310_config_type {
+ STK3310_GAIN,
+ STK3310_IT,
+ STK3310_TYPE_COUNT
+};
+
+struct stk3310_data {
+ struct i2c_client *client;
+ struct mutex lock;
+ /* Cache table for storing config values */
+ int cache[2][STK3310_TYPE_COUNT];
+};
+
+static const struct iio_chan_spec stk3310_channels[] = {
+ {
+ .channel = 0,
+ .type = IIO_LIGHT,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_INT_TIME),
+ },
+ {
+ .channel = 1,
+ .type = IIO_PROXIMITY,
+ .info_mask_separate =
+ BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_INT_TIME),
+ }
+};
+
+static ssize_t stk3310_get_it_vals(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int i;
+ int len;
+
+ for (i = 0, len = 0; i < ARRAY_SIZE(stk3310_it_table); i++) {
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
+ stk3310_it_table[i][0],
+ stk3310_it_table[i][1]);
+ }
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static IIO_CONST_ATTR(in_illuminance_scale_available, STK3310_SCALE_AVAILABLE);
+
+static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
+ S_IRUGO, stk3310_get_it_vals, NULL, 0);
+
+static IIO_DEVICE_ATTR(in_proximity_integration_time_available,
+ S_IRUGO, stk3310_get_it_vals, NULL, 0);
+
+static struct attribute *stk3310_attributes[] = {
+ &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
+ &iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
+ &iio_dev_attr_in_proximity_integration_time_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group stk3310_attribute_group = {
+ .attrs = stk3310_attributes
+};
+
+static int stk3310_get_index(const int table[][2], int table_size,
+ int val, int val2)
+{
+ int i;
+
+ for (i = 0; i < table_size; i++) {
+ if (val == table[i][0] && val2 == table[i][1])
+ return i;
+ }
+
+ return -EINVAL;
+}
+
+static int stk3310_set_cfg(struct stk3310_data *data,
+ enum stk3310_data_type type,
+ enum stk3310_config_type cfg,
+ u8 val)
+{
+ u8 reg;
+ u8 shift;
+ u8 masked_reg;
+ u8 mask;
+ int ret;
+
+ if (val < 0)
+ return -EINVAL;
+ switch (type) {
+ case STK3310_ALS:
+ reg = STK3310_REG_ALSCTRL;
+ break;
+ case STK3310_PS:
+ reg = STK3310_REG_PSCTRL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ switch (cfg) {
+ case STK3310_GAIN:
+ if (val > STK3310_GAIN_MAX)
+ return -EINVAL;
+ shift = STK3310_GAIN_SHIFT;
+ mask = STK3310_GAIN_MASK;
+ break;
+ case STK3310_IT:
+ if (val > STK3310_IT_MAX)
+ return -EINVAL;
+ shift = STK3310_IT_SHIFT;
+ mask = STK3310_IT_MASK;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = i2c_smbus_read_byte_data(data->client, reg);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "register read failed\n");
+ return ret;
+ }
+ masked_reg = ret & (~mask);
+ masked_reg |= (val << shift);
+
+ ret = i2c_smbus_write_byte_data(data->client, reg, masked_reg);
+ if (ret < 0)
+ dev_err(&data->client->dev, "sensor configuration failed\n");
+ else
+ data->cache[type][cfg] = val;
+
+ return ret;
+}
+
+static int stk3310_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ int ret;
+ int index;
+ u8 reg;
+ enum stk3310_data_type type;
+ struct stk3310_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+
+ switch (chan->type) {
+ case IIO_LIGHT:
+ type = STK3310_ALS;
+ reg = STK3310_REG_ALS_DATA_MSB;
+ break;
+ case IIO_PROXIMITY:
+ type = STK3310_PS;
+ reg = STK3310_REG_PS_DATA_MSB;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&data->lock);
+ ret = i2c_smbus_read_word_swapped(client, reg);
+ if (ret < 0) {
+ dev_err(&client->dev, "register read failed\n");
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+ *val = ret;
+ index = data->cache[STK3310_ALS][STK3310_GAIN];
+ if (type == STK3310_PS) {
+ /*
+ * Invert the proximity data so we return low values
+ * for close objects and high values for far ones.
+ */
+ index = data->cache[STK3310_PS][STK3310_GAIN];
+ *val = stk3310_ps_max[index] - *val;
+ }
+ mutex_unlock(&data->lock);
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_INT_TIME:
+ index = data->cache[type][STK3310_IT];
+ *val = stk3310_it_table[index][0];
+ *val2 = stk3310_it_table[index][1];
+ return IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_SCALE:
+ index = data->cache[type][STK3310_GAIN];
+ *val = stk3310_scale_table[index][0];
+ *val2 = stk3310_scale_table[index][1];
+ return IIO_VAL_INT_PLUS_MICRO;
+ }
+
+ return -EINVAL;
+}
+
+static int stk3310_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ int ret;
+ int index;
+ enum stk3310_data_type type;
+ struct stk3310_data *data = iio_priv(indio_dev);
+
+ switch (chan->type) {
+ case IIO_LIGHT:
+ type = STK3310_ALS;
+ break;
+ case IIO_PROXIMITY:
+ type = STK3310_PS;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ index = stk3310_get_index(stk3310_it_table,
+ ARRAY_SIZE(stk3310_it_table),
+ val, val2);
+ if (index < 0)
+ return -EINVAL;
+ mutex_lock(&data->lock);
+ ret = stk3310_set_cfg(data, type, STK3310_IT, index);
+ mutex_unlock(&data->lock);
+ return ret;
+
+ case IIO_CHAN_INFO_SCALE:
+ index = stk3310_get_index(stk3310_scale_table,
+ ARRAY_SIZE(stk3310_scale_table),
+ val, val2);
+ if (index < 0)
+ return -EINVAL;
+ mutex_lock(&data->lock);
+ ret = stk3310_set_cfg(data, type, STK3310_GAIN, index);
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info stk3310_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = stk3310_read_raw,
+ .write_raw = stk3310_write_raw,
+ .attrs = &stk3310_attribute_group,
+};
+
+static int stk3310_cache_store(struct stk3310_data *data)
+{
+ int ret;
+
+ mutex_lock(&data->lock);
+ ret = i2c_smbus_read_byte_data(data->client, STK3310_REG_ALSCTRL);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "register read failed\n");
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ data->cache[STK3310_ALS][STK3310_GAIN] =
+ (ret & STK3310_GAIN_MASK) >> STK3310_GAIN_SHIFT;
+ data->cache[STK3310_ALS][STK3310_IT] =
+ (ret & STK3310_IT_MASK) >> STK3310_IT_SHIFT;
+
+ ret = i2c_smbus_read_byte_data(data->client, STK3310_REG_PSCTRL);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "register read failed\n");
+ mutex_unlock(&data->lock);
+ return ret;
+ }
+
+ data->cache[STK3310_PS][STK3310_GAIN] =
+ (ret & STK3310_GAIN_MASK) >> STK3310_GAIN_SHIFT;
+ data->cache[STK3310_PS][STK3310_IT] =
+ (ret & STK3310_IT_MASK) >> STK3310_IT_SHIFT;
+ mutex_unlock(&data->lock);
+
+ return ret;
+}
+
+static int stk3310_set_state(struct stk3310_data *data, u8 state)
+{
+ int ret;
+ int masked_reg;
+ struct i2c_client *client = data->client;
+
+ /* 3-bit state; 0b100 is not supported. */
+ if (state < 0 || state > 7 || state == 4)
+ return -EINVAL;
+
+ mutex_lock(&data->lock);
+ ret = i2c_smbus_read_byte_data(data->client, STK3310_REG_STATE);
+ if (ret < 0) {
+ mutex_unlock(&data->lock);
+ dev_err(&client->dev, "register read failed\n");
+ return ret;
+ }
+ masked_reg = ret & (~STK3310_STATE_MASK);
+ masked_reg |= state;
+
+ ret = i2c_smbus_write_byte_data(data->client, STK3310_REG_STATE,
+ masked_reg);
+ if (ret < 0)
+ dev_err(&client->dev, "failed to change sensor state\n");
+
+ mutex_unlock(&data->lock);
+
+ return ret;
+}
+
+static int stk3310_init(struct iio_dev *indio_dev)
+{
+ int ret;
+ u8 state;
+ struct stk3310_data *data = iio_priv(indio_dev);
+ struct i2c_client *client = data->client;
+
+ ret = i2c_smbus_read_byte_data(client, STK3310_REG_PDT_ID);
+ if (ret != STK3310_CHIP_ID_VAL &&
+ ret != STK3311_CHIP_ID_VAL) {
+ dev_err(&client->dev, "invalid chip id: 0x%x\n", ret);
+ return -ENODEV;
+ }
+
+ state = STK3310_STATE_EN_ALS | STK3310_STATE_EN_PS;
+ ret = stk3310_set_state(data, state);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to enable sensor");
+ return ret;
+ }
+
+ /* Cache the initial configuration values */
+ return stk3310_cache_store(data);
+}
+
+static int stk3310_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret;
+ struct iio_dev *indio_dev;
+ struct stk3310_data *data;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ if (!indio_dev) {
+ dev_err(&client->dev, "iio allocation failed!\n");
+ return -ENOMEM;
+ }
+
+ data = iio_priv(indio_dev);
+ data->client = client;
+ i2c_set_clientdata(client, indio_dev);
+ mutex_init(&data->lock);
+
+ indio_dev->dev.parent = &client->dev;
+ indio_dev->info = &stk3310_info;
+ indio_dev->name = STK3310_DRIVER_NAME;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = stk3310_channels;
+ indio_dev->num_channels = ARRAY_SIZE(stk3310_channels);
+
+ ret = stk3310_init(indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "sensor initialization failed\n");
+ return ret;
+ }
+
+ ret = devm_iio_device_register(&client->dev, indio_dev);
+ if (ret < 0) {
+ dev_err(&client->dev, "device_register failed\n");
+ stk3310_set_state(data, STK3310_STATE_STANDBY);
+ }
+
+ return ret;
+}
+
+static int stk3310_remove(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct stk3310_data *data = iio_priv(indio_dev);
+
+ return stk3310_set_state(data, STK3310_STATE_STANDBY);
+}
+
+static const struct i2c_device_id stk3310_i2c_id[] = {
+ {"STK3310", 0},
+ {"STK3311", 0},
+ {}
+};
+
+static const struct acpi_device_id stk3310_acpi_id[] = {
+ {"STK3310", 0},
+ {"STK3311", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(acpi, stk3310_acpi_id);
+
+static struct i2c_driver stk3310_driver = {
+ .driver = {
+ .name = "stk3310",
+ .acpi_match_table = ACPI_PTR(stk3310_acpi_id),
+ },
+ .probe = stk3310_probe,
+ .remove = stk3310_remove,
+ .id_table = stk3310_i2c_id,
+};
+
+module_i2c_driver(stk3310_driver);
+
+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@xxxxxxxxx>");
+MODULE_DESCRIPTION("STK3310 Ambient Light and Proximity Sensor driver");
+MODULE_LICENSE("GPL v2");
--
1.9.1
--
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