iio: light: Add support for Sensortek STK3310
authorTiberiu Breana <tiberiu.a.breana@intel.com>
Mon, 27 Apr 2015 15:34:00 +0000 (18:34 +0300)
committerJonathan Cameron <jic23@kernel.org>
Sun, 10 May 2015 19:31:42 +0000 (20:31 +0100)
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.
- power management

Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/light/Kconfig
drivers/iio/light/Makefile
drivers/iio/light/stk3310.c [new file with mode: 0644]

index a437bad466864dbd56869f72d0a0d55ab1ebbeca..3d7bafa6a0e3406f0000054495c516bc5aa467eb 100644 (file)
@@ -175,6 +175,17 @@ 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
index ad7c30fe443b26f6760bfe607a1a035b760752d3..90e7fd258557191416bbbdceada3b75e46f44939 100644 (file)
@@ -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 (file)
index 0000000..0f8c450
--- /dev/null
@@ -0,0 +1,471 @@
+/**
+ * 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/regmap.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_PS_DATA_LSB                        0x12
+#define STK3310_REG_ALS_DATA_MSB               0x13
+#define STK3310_REG_ALS_DATA_LSB               0x14
+#define STK3310_REG_ID                         0x3E
+#define STK3310_MAX_REG                                0x80
+
+#define STK3310_STATE_EN_PS                    0x01
+#define STK3310_STATE_EN_ALS                   0x02
+#define STK3310_STATE_STANDBY                  0x00
+
+#define STK3310_CHIP_ID_VAL                    0x13
+#define STK3311_CHIP_ID_VAL                    0x1D
+#define STK3310_PS_MAX_VAL                     0xFFFF
+
+#define STK3310_DRIVER_NAME                    "stk3310"
+#define STK3310_REGMAP_NAME                    "stk3310_regmap"
+
+#define STK3310_SCALE_AVAILABLE                        "6.4 1.6 0.4 0.1"
+
+#define STK3310_IT_AVAILABLE \
+       "0.000185 0.000370 0.000741 0.001480 0.002960 0.005920 0.011840 " \
+       "0.023680 0.047360 0.094720 0.189440 0.378880 0.757760 1.515520 " \
+       "3.031040 6.062080"
+
+#define STK3310_REGFIELD(name)                                             \
+       do {                                                                \
+               data->reg_##name =                                          \
+                       devm_regmap_field_alloc(&client->dev, regmap,       \
+                               stk3310_reg_field_##name);                  \
+               if (IS_ERR(data->reg_##name)) {                             \
+                       dev_err(&client->dev, "reg field alloc failed.\n"); \
+                       return PTR_ERR(data->reg_##name);                   \
+               }                                                           \
+       } while (0)
+
+static const struct reg_field stk3310_reg_field_state =
+                               REG_FIELD(STK3310_REG_STATE, 0, 2);
+static const struct reg_field stk3310_reg_field_als_gain =
+                               REG_FIELD(STK3310_REG_ALSCTRL, 4, 5);
+static const struct reg_field stk3310_reg_field_ps_gain =
+                               REG_FIELD(STK3310_REG_PSCTRL, 4, 5);
+static const struct reg_field stk3310_reg_field_als_it =
+                               REG_FIELD(STK3310_REG_ALSCTRL, 0, 3);
+static const struct reg_field stk3310_reg_field_ps_it =
+                               REG_FIELD(STK3310_REG_PSCTRL, 0, 3);
+
+/*
+ * 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, 185},       {0, 370},       {0, 741},       {0, 1480},
+       {0, 2960},      {0, 5920},      {0, 11840},     {0, 23680},
+       {0, 47360},     {0, 94720},     {0, 189440},    {0, 378880},
+       {0, 757760},    {1, 515520},    {3, 31040},     {6, 62080},
+};
+
+struct stk3310_data {
+       struct i2c_client *client;
+       struct mutex lock;
+       bool als_enabled;
+       bool ps_enabled;
+       struct regmap *regmap;
+       struct regmap_field *reg_state;
+       struct regmap_field *reg_als_gain;
+       struct regmap_field *reg_ps_gain;
+       struct regmap_field *reg_als_it;
+       struct regmap_field *reg_ps_it;
+};
+
+static const struct iio_chan_spec stk3310_channels[] = {
+       {
+               .type = IIO_LIGHT,
+               .info_mask_separate =
+                       BIT(IIO_CHAN_INFO_RAW) |
+                       BIT(IIO_CHAN_INFO_SCALE) |
+                       BIT(IIO_CHAN_INFO_INT_TIME),
+       },
+       {
+               .type = IIO_PROXIMITY,
+               .info_mask_separate =
+                       BIT(IIO_CHAN_INFO_RAW) |
+                       BIT(IIO_CHAN_INFO_SCALE) |
+                       BIT(IIO_CHAN_INFO_INT_TIME),
+       }
+};
+
+static IIO_CONST_ATTR(in_illuminance_scale_available, STK3310_SCALE_AVAILABLE);
+
+static IIO_CONST_ATTR(in_proximity_scale_available, STK3310_SCALE_AVAILABLE);
+
+static IIO_CONST_ATTR(in_illuminance_integration_time_available,
+                     STK3310_IT_AVAILABLE);
+
+static IIO_CONST_ATTR(in_proximity_integration_time_available,
+                     STK3310_IT_AVAILABLE);
+
+static struct attribute *stk3310_attributes[] = {
+       &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
+       &iio_const_attr_in_proximity_scale_available.dev_attr.attr,
+       &iio_const_attr_in_illuminance_integration_time_available.dev_attr.attr,
+       &iio_const_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_read_raw(struct iio_dev *indio_dev,
+                           struct iio_chan_spec const *chan,
+                           int *val, int *val2, long mask)
+{
+       u8 reg;
+       u16 buf;
+       int ret;
+       unsigned int index;
+       struct stk3310_data *data = iio_priv(indio_dev);
+       struct i2c_client *client = data->client;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               if (chan->type == IIO_LIGHT)
+                       reg = STK3310_REG_ALS_DATA_MSB;
+               else if (chan->type == IIO_PROXIMITY)
+                       reg = STK3310_REG_PS_DATA_MSB;
+               else
+                       return -EINVAL;
+               mutex_lock(&data->lock);
+               ret = regmap_bulk_read(data->regmap, reg, &buf, 2);
+               if (ret < 0) {
+                       dev_err(&client->dev, "register read failed\n");
+                       mutex_unlock(&data->lock);
+                       return ret;
+               }
+               *val = swab16(buf);
+               if (chan->type == IIO_PROXIMITY) {
+                       /*
+                        * Invert the proximity data so we return low values
+                        * for close objects and high values for far ones.
+                        */
+                       regmap_field_read(data->reg_ps_gain, &index);
+                       *val = stk3310_ps_max[index] - *val;
+               }
+               mutex_unlock(&data->lock);
+               return IIO_VAL_INT;
+       case IIO_CHAN_INFO_INT_TIME:
+               if (chan->type == IIO_LIGHT)
+                       regmap_field_read(data->reg_als_it, &index);
+               else
+                       regmap_field_read(data->reg_ps_it, &index);
+               *val = stk3310_it_table[index][0];
+               *val2 = stk3310_it_table[index][1];
+               return IIO_VAL_INT_PLUS_MICRO;
+       case IIO_CHAN_INFO_SCALE:
+               if (chan->type == IIO_LIGHT)
+                       regmap_field_read(data->reg_als_gain, &index);
+               else
+                       regmap_field_read(data->reg_ps_gain, &index);
+               *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;
+       unsigned int index;
+       struct stk3310_data *data = iio_priv(indio_dev);
+
+       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);
+               if (chan->type == IIO_LIGHT)
+                       ret = regmap_field_write(data->reg_als_it, index);
+               else
+                       ret = regmap_field_write(data->reg_ps_it, index);
+               if (ret < 0)
+                       dev_err(&data->client->dev,
+                                       "sensor configuration failed\n");
+               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);
+               if (chan->type == IIO_LIGHT)
+                       ret = regmap_field_write(data->reg_als_gain, index);
+               else
+                       ret = regmap_field_write(data->reg_ps_gain, index);
+               if (ret < 0)
+                       dev_err(&data->client->dev,
+                                       "sensor configuration failed\n");
+               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_set_state(struct stk3310_data *data, u8 state)
+{
+       int ret;
+       struct i2c_client *client = data->client;
+
+       /* 3-bit state; 0b100 is not supported. */
+       if (state > 7 || state == 4)
+               return -EINVAL;
+
+       mutex_lock(&data->lock);
+       ret = regmap_field_write(data->reg_state, state);
+       if (ret < 0) {
+               dev_err(&client->dev, "failed to change sensor state\n");
+       } else if (state != STK3310_STATE_STANDBY) {
+               /* Don't reset the 'enabled' flags if we're going in standby */
+               data->ps_enabled  = !!(state & 0x01);
+               data->als_enabled = !!(state & 0x02);
+       }
+       mutex_unlock(&data->lock);
+
+       return ret;
+}
+
+static int stk3310_init(struct iio_dev *indio_dev)
+{
+       int ret;
+       int chipid;
+       u8 state;
+       struct stk3310_data *data = iio_priv(indio_dev);
+       struct i2c_client *client = data->client;
+
+       regmap_read(data->regmap, STK3310_REG_ID, &chipid);
+       if (chipid != STK3310_CHIP_ID_VAL &&
+           chipid != STK3311_CHIP_ID_VAL) {
+               dev_err(&client->dev, "invalid chip id: 0x%x\n", chipid);
+               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;
+}
+
+static bool stk3310_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+       switch (reg) {
+       case STK3310_REG_ALS_DATA_MSB:
+       case STK3310_REG_ALS_DATA_LSB:
+       case STK3310_REG_PS_DATA_LSB:
+       case STK3310_REG_PS_DATA_MSB:
+               return true;
+       default:
+               return false;
+       }
+}
+
+static struct regmap_config stk3310_regmap_config = {
+       .name = STK3310_REGMAP_NAME,
+       .reg_bits = 8,
+       .val_bits = 8,
+       .max_register = STK3310_MAX_REG,
+       .cache_type = REGCACHE_RBTREE,
+       .volatile_reg = stk3310_is_volatile_reg,
+};
+
+static int stk3310_regmap_init(struct stk3310_data *data)
+{
+       struct regmap *regmap;
+       struct i2c_client *client;
+
+       client = data->client;
+       regmap = devm_regmap_init_i2c(client, &stk3310_regmap_config);
+       if (IS_ERR(regmap)) {
+               dev_err(&client->dev, "regmap initialization failed.\n");
+               return PTR_ERR(regmap);
+       }
+       data->regmap = regmap;
+
+       STK3310_REGFIELD(state);
+       STK3310_REGFIELD(als_gain);
+       STK3310_REGFIELD(ps_gain);
+       STK3310_REGFIELD(als_it);
+       STK3310_REGFIELD(ps_it);
+
+       return 0;
+}
+
+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);
+
+       ret = stk3310_regmap_init(data);
+       if (ret < 0)
+               return ret;
+
+       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)
+               return ret;
+
+       ret = iio_device_register(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);
+
+       iio_device_unregister(indio_dev);
+       return stk3310_set_state(iio_priv(indio_dev), STK3310_STATE_STANDBY);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stk3310_suspend(struct device *dev)
+{
+       struct stk3310_data *data;
+
+       data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+       return stk3310_set_state(data, STK3310_STATE_STANDBY);
+}
+
+static int stk3310_resume(struct device *dev)
+{
+       int state = 0;
+       struct stk3310_data *data;
+
+       data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+       if (data->ps_enabled)
+               state |= STK3310_STATE_EN_PS;
+       if (data->als_enabled)
+               state |= STK3310_STATE_EN_ALS;
+
+       return stk3310_set_state(data, state);
+}
+
+static SIMPLE_DEV_PM_OPS(stk3310_pm_ops, stk3310_suspend, stk3310_resume);
+
+#define STK3310_PM_OPS (&stk3310_pm_ops)
+#else
+#define STK3310_PM_OPS NULL
+#endif
+
+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",
+               .pm = STK3310_PM_OPS,
+               .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@intel.com>");
+MODULE_DESCRIPTION("STK3310 Ambient Light and Proximity Sensor driver");
+MODULE_LICENSE("GPL v2");