iio: light: Add threshold interrupt support for STK3310
authorTiberiu Breana <tiberiu.a.breana@intel.com>
Mon, 27 Apr 2015 15:34:01 +0000 (18:34 +0300)
committerJonathan Cameron <jic23@kernel.org>
Sun, 10 May 2015 19:31:42 +0000 (20:31 +0100)
Added interrupt support for proximity threshold events
to the stk3310 driver.

Signed-off-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/light/stk3310.c

index 0f8c450..e79b9d8 100644 (file)
 
 #include <linux/acpi.h>
 #include <linux/i2c.h>
+#include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iio/events.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_INT                                0x04
+#define STK3310_REG_THDH_PS                    0x06
+#define STK3310_REG_THDL_PS                    0x08
+#define STK3310_REG_FLAG                       0x10
 #define STK3310_REG_PS_DATA_MSB                        0x11
 #define STK3310_REG_PS_DATA_LSB                        0x12
 #define STK3310_REG_ALS_DATA_MSB               0x13
 
 #define STK3310_CHIP_ID_VAL                    0x13
 #define STK3311_CHIP_ID_VAL                    0x1D
+#define STK3310_PSINT_EN                       0x01
 #define STK3310_PS_MAX_VAL                     0xFFFF
+#define STK3310_THRESH_MAX                     0xFFFF
 
 #define STK3310_DRIVER_NAME                    "stk3310"
 #define STK3310_REGMAP_NAME                    "stk3310_regmap"
+#define STK3310_EVENT                          "stk3310_event"
+#define STK3310_GPIO                           "stk3310_gpio"
 
 #define STK3310_SCALE_AVAILABLE                        "6.4 1.6 0.4 0.1"
 
@@ -67,7 +78,12 @@ 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);
-
+static const struct reg_field stk3310_reg_field_int_ps =
+                               REG_FIELD(STK3310_REG_INT, 0, 2);
+static const struct reg_field stk3310_reg_field_flag_psint =
+                               REG_FIELD(STK3310_REG_FLAG, 4, 4);
+static const struct reg_field stk3310_reg_field_flag_nf =
+                               REG_FIELD(STK3310_REG_FLAG, 0, 0);
 /*
  * Maximum PS values with regard to scale. Used to export the 'inverse'
  * PS value (high values for far objects, low values for near objects).
@@ -96,12 +112,33 @@ struct stk3310_data {
        struct mutex lock;
        bool als_enabled;
        bool ps_enabled;
+       u64 timestamp;
        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;
+       struct regmap_field *reg_int_ps;
+       struct regmap_field *reg_flag_psint;
+       struct regmap_field *reg_flag_nf;
+};
+
+static const struct iio_event_spec stk3310_events[] = {
+       /* Proximity event */
+       {
+               .type = IIO_EV_TYPE_THRESH,
+               .dir = IIO_EV_DIR_FALLING,
+               .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                                BIT(IIO_EV_INFO_ENABLE),
+       },
+       /* Out-of-proximity event */
+       {
+               .type = IIO_EV_TYPE_THRESH,
+               .dir = IIO_EV_DIR_RISING,
+               .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                                BIT(IIO_EV_INFO_ENABLE),
+       },
 };
 
 static const struct iio_chan_spec stk3310_channels[] = {
@@ -118,6 +155,8 @@ static const struct iio_chan_spec stk3310_channels[] = {
                        BIT(IIO_CHAN_INFO_RAW) |
                        BIT(IIO_CHAN_INFO_SCALE) |
                        BIT(IIO_CHAN_INFO_INT_TIME),
+               .event_spec = stk3310_events,
+               .num_event_specs = ARRAY_SIZE(stk3310_events),
        }
 };
 
@@ -156,6 +195,118 @@ static int stk3310_get_index(const int table[][2], int table_size,
        return -EINVAL;
 }
 
+static int stk3310_read_event(struct iio_dev *indio_dev,
+                             const struct iio_chan_spec *chan,
+                             enum iio_event_type type,
+                             enum iio_event_direction dir,
+                             enum iio_event_info info,
+                             int *val, int *val2)
+{
+       u8 reg;
+       u16 buf;
+       int ret;
+       unsigned int index;
+       struct stk3310_data *data = iio_priv(indio_dev);
+
+       if (info != IIO_EV_INFO_VALUE)
+               return -EINVAL;
+
+       /*
+        * Only proximity interrupts are implemented at the moment.
+        * Since we're inverting proximity values, the sensor's 'high'
+        * threshold will become our 'low' threshold, associated with
+        * 'near' events. Similarly, the sensor's 'low' threshold will
+        * be our 'high' threshold, associated with 'far' events.
+        */
+       if (dir == IIO_EV_DIR_RISING)
+               reg = STK3310_REG_THDL_PS;
+       else if (dir == IIO_EV_DIR_FALLING)
+               reg = STK3310_REG_THDH_PS;
+       else
+               return -EINVAL;
+
+       mutex_lock(&data->lock);
+       ret = regmap_bulk_read(data->regmap, reg, &buf, 2);
+       mutex_unlock(&data->lock);
+       if (ret < 0) {
+               dev_err(&data->client->dev, "register read failed\n");
+               return ret;
+       }
+       regmap_field_read(data->reg_ps_gain, &index);
+       *val = swab16(stk3310_ps_max[index] - buf);
+
+       return IIO_VAL_INT;
+}
+
+static int stk3310_write_event(struct iio_dev *indio_dev,
+                              const struct iio_chan_spec *chan,
+                              enum iio_event_type type,
+                              enum iio_event_direction dir,
+                              enum iio_event_info info,
+                              int val, int val2)
+{
+       u8 reg;
+       u16 buf;
+       int ret;
+       unsigned int index;
+       struct stk3310_data *data = iio_priv(indio_dev);
+       struct i2c_client *client = data->client;
+
+       regmap_field_read(data->reg_ps_gain, &index);
+       if (val > stk3310_ps_max[index])
+               return -EINVAL;
+
+       if (dir == IIO_EV_DIR_RISING)
+               reg = STK3310_REG_THDL_PS;
+       else if (dir == IIO_EV_DIR_FALLING)
+               reg = STK3310_REG_THDH_PS;
+       else
+               return -EINVAL;
+
+       buf = swab16(stk3310_ps_max[index] - val);
+       ret = regmap_bulk_write(data->regmap, reg, &buf, 2);
+       if (ret < 0)
+               dev_err(&client->dev, "failed to set PS threshold!\n");
+
+       return ret;
+}
+
+static int stk3310_read_event_config(struct iio_dev *indio_dev,
+                                    const struct iio_chan_spec *chan,
+                                    enum iio_event_type type,
+                                    enum iio_event_direction dir)
+{
+       unsigned int event_val;
+       struct stk3310_data *data = iio_priv(indio_dev);
+
+       regmap_field_read(data->reg_int_ps, &event_val);
+
+       return event_val;
+}
+
+static int stk3310_write_event_config(struct iio_dev *indio_dev,
+                                     const struct iio_chan_spec *chan,
+                                     enum iio_event_type type,
+                                     enum iio_event_direction dir,
+                                     int state)
+{
+       int ret;
+       struct stk3310_data *data = iio_priv(indio_dev);
+       struct i2c_client *client = data->client;
+
+       if (state < 0 || state > 7)
+               return -EINVAL;
+
+       /* Set INT_PS value */
+       mutex_lock(&data->lock);
+       ret = regmap_field_write(data->reg_int_ps, state);
+       if (ret < 0)
+               dev_err(&client->dev, "failed to set interrupt mode\n");
+       mutex_unlock(&data->lock);
+
+       return ret;
+}
+
 static int stk3310_read_raw(struct iio_dev *indio_dev,
                            struct iio_chan_spec const *chan,
                            int *val, int *val2, long mask)
@@ -266,6 +417,10 @@ static const struct iio_info stk3310_info = {
        .read_raw               = stk3310_read_raw,
        .write_raw              = stk3310_write_raw,
        .attrs                  = &stk3310_attribute_group,
+       .read_event_value       = stk3310_read_event,
+       .write_event_value      = stk3310_write_event,
+       .read_event_config      = stk3310_read_event_config,
+       .write_event_config     = stk3310_write_event_config,
 };
 
 static int stk3310_set_state(struct stk3310_data *data, u8 state)
@@ -308,8 +463,43 @@ static int stk3310_init(struct iio_dev *indio_dev)
 
        state = STK3310_STATE_EN_ALS | STK3310_STATE_EN_PS;
        ret = stk3310_set_state(data, state);
-       if (ret < 0)
+       if (ret < 0) {
                dev_err(&client->dev, "failed to enable sensor");
+               return ret;
+       }
+
+       /* Enable PS interrupts */
+       ret = regmap_field_write(data->reg_int_ps, STK3310_PSINT_EN);
+       if (ret < 0)
+               dev_err(&client->dev, "failed to enable interrupts!\n");
+
+       return ret;
+}
+
+static int stk3310_gpio_probe(struct i2c_client *client)
+{
+       struct device *dev;
+       struct gpio_desc *gpio;
+       int ret;
+
+       if (!client)
+               return -EINVAL;
+
+       dev = &client->dev;
+
+       /* gpio interrupt pin */
+       gpio = devm_gpiod_get_index(dev, STK3310_GPIO, 0);
+       if (IS_ERR(gpio)) {
+               dev_err(dev, "acpi gpio get index failed\n");
+               return PTR_ERR(gpio);
+       }
+
+       ret = gpiod_direction_input(gpio);
+       if (ret)
+               return ret;
+
+       ret = gpiod_to_irq(gpio);
+       dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
 
        return ret;
 }
@@ -321,6 +511,7 @@ static bool stk3310_is_volatile_reg(struct device *dev, unsigned int reg)
        case STK3310_REG_ALS_DATA_LSB:
        case STK3310_REG_PS_DATA_LSB:
        case STK3310_REG_PS_DATA_MSB:
+       case STK3310_REG_FLAG:
                return true;
        default:
                return false;
@@ -354,10 +545,55 @@ static int stk3310_regmap_init(struct stk3310_data *data)
        STK3310_REGFIELD(ps_gain);
        STK3310_REGFIELD(als_it);
        STK3310_REGFIELD(ps_it);
+       STK3310_REGFIELD(int_ps);
+       STK3310_REGFIELD(flag_psint);
+       STK3310_REGFIELD(flag_nf);
 
        return 0;
 }
 
+static irqreturn_t stk3310_irq_handler(int irq, void *private)
+{
+       struct iio_dev *indio_dev = private;
+       struct stk3310_data *data = iio_priv(indio_dev);
+
+       data->timestamp = iio_get_time_ns();
+
+       return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t stk3310_irq_event_handler(int irq, void *private)
+{
+       int ret;
+       unsigned int dir;
+       u64 event;
+
+       struct iio_dev *indio_dev = private;
+       struct stk3310_data *data = iio_priv(indio_dev);
+
+       /* Read FLAG_NF to figure out what threshold has been met. */
+       mutex_lock(&data->lock);
+       ret = regmap_field_read(data->reg_flag_nf, &dir);
+       if (ret < 0) {
+               dev_err(&data->client->dev, "register read failed\n");
+               mutex_unlock(&data->lock);
+               return ret;
+       }
+       event = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 1,
+                                    IIO_EV_TYPE_THRESH,
+                                    (dir ? IIO_EV_DIR_RISING :
+                                           IIO_EV_DIR_FALLING));
+       iio_push_event(indio_dev, event, data->timestamp);
+
+       /* Reset the interrupt flag */
+       ret = regmap_field_write(data->reg_flag_psint, 0);
+       if (ret < 0)
+               dev_err(&data->client->dev, "failed to reset interrupts\n");
+       mutex_unlock(&data->lock);
+
+       return IRQ_HANDLED;
+}
+
 static int stk3310_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
 {
@@ -397,6 +633,21 @@ static int stk3310_probe(struct i2c_client *client,
                stk3310_set_state(data, STK3310_STATE_STANDBY);
        }
 
+       if (client->irq <= 0)
+               client->irq = stk3310_gpio_probe(client);
+
+       if (client->irq >= 0) {
+               ret = devm_request_threaded_irq(&client->dev, client->irq,
+                                               stk3310_irq_handler,
+                                               stk3310_irq_event_handler,
+                                               IRQF_TRIGGER_FALLING |
+                                               IRQF_ONESHOT,
+                                               STK3310_EVENT, indio_dev);
+               if (ret < 0)
+                       dev_err(&client->dev, "request irq %d failed\n",
+                                       client->irq);
+       }
+
        return ret;
 }