iio: light: us5182d: Add interrupt support and events

Add interrupt support for proximity.
Add two threshold events to signal rising and falling directions.

Signed-off-by: Adriana Reus <adriana.reus@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 270 insertions, 1 deletions

diff --git a/drivers/iio/light/us5182d.c b/drivers/iio/light/us5182d.c
index f24b687bd152..213f7785095f 100644
--- a/drivers/iio/light/us5182d.c
+++ b/drivers/iio/light/us5182d.c
@@ -20,7 +20,10 @@
 #include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
+#include <linux/iio/events.h>
 #include <linux/iio/iio.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/iio/sysfs.h>
 #include <linux/mutex.h>
 #include <linux/pm.h>
@@ -30,6 +33,8 @@
 #define US5182D_CFG0_ONESHOT_EN                         BIT(6)
 #define US5182D_CFG0_SHUTDOWN_EN                        BIT(7)
 #define US5182D_CFG0_WORD_ENABLE                        BIT(0)
+#define US5182D_CFG0_PROX                               BIT(3)
+#define US5182D_CFG0_PX_IRQ                             BIT(2)
 
 #define US5182D_REG_CFG1                                0x01
 #define US5182D_CFG1_ALS_RES16                          BIT(4)
@@ -41,6 +46,7 @@
 
 #define US5182D_REG_CFG3                                0x03
 #define US5182D_CFG3_LED_CURRENT100                     (BIT(4) | BIT(5))
+#define US5182D_CFG3_INT_SOURCE_PX                      BIT(3)
 
 #define US5182D_REG_CFG4                                0x10
 
@@ -55,6 +61,13 @@
 #define US5182D_REG_AUTO_LDARK_GAIN             0x29
 #define US5182D_REG_AUTO_HDARK_GAIN             0x2a
 
+/* Thresholds for events: px low (0x08-l, 0x09-h), px high (0x0a-l 0x0b-h) */
+#define US5182D_REG_PXL_TH                      0x08
+#define US5182D_REG_PXH_TH                      0x0a
+
+#define US5182D_REG_PXL_TH_DEFAULT              1000
+#define US5182D_REG_PXH_TH_DEFAULT              30000
+
 #define US5182D_OPMODE_ALS                      0x01
 #define US5182D_OPMODE_PX                       0x02
 #define US5182D_OPMODE_SHIFT                    4
@@ -84,6 +97,8 @@
 #define US5182D_READ_WORD                       2
 #define US5182D_OPSTORE_SLEEP_TIME              20 /* ms */
 #define US5182D_SLEEP_MS                        3000 /* ms */
+#define US5182D_PXH_TH_DISABLE                  0xffff
+#define US5182D_PXL_TH_DISABLE                  0x0000
 
 /* Available ranges: [12354, 7065, 3998, 2202, 1285, 498, 256, 138] lux */
 static const int us5182d_scales[] = {188500, 107800, 61000, 33600, 19600, 7600,
@@ -119,6 +134,12 @@ struct us5182d_data {
         u8 upper_dark_gain;
         u16 *us5182d_dark_ths;
 
+        u16 px_low_th;
+        u16 px_high_th;
+
+        int rising_en;
+        int falling_en;
+
         u8 opmode;
         u8 power_mode;
 
@@ -148,10 +169,26 @@ static const struct {
         {US5182D_REG_CFG1, US5182D_CFG1_ALS_RES16},
         {US5182D_REG_CFG2, (US5182D_CFG2_PX_RES16 |
                             US5182D_CFG2_PXGAIN_DEFAULT)},
-        {US5182D_REG_CFG3, US5182D_CFG3_LED_CURRENT100},
+        {US5182D_REG_CFG3, US5182D_CFG3_LED_CURRENT100 |
+                           US5182D_CFG3_INT_SOURCE_PX},
         {US5182D_REG_CFG4, 0x00},
 };
 
+static const struct iio_event_spec us5182d_events[] = {
+        {
+                .type = IIO_EV_TYPE_THRESH,
+                .dir = IIO_EV_DIR_RISING,
+                .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                                BIT(IIO_EV_INFO_ENABLE),
+        },
+        {
+                .type = IIO_EV_TYPE_THRESH,
+                .dir = IIO_EV_DIR_FALLING,
+                .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                                BIT(IIO_EV_INFO_ENABLE),
+        },
+};
+
 static const struct iio_chan_spec us5182d_channels[] = {
         {
                 .type = IIO_LIGHT,
@@ -161,6 +198,8 @@ static const struct iio_chan_spec us5182d_channels[] = {
         {
                 .type = IIO_PROXIMITY,
                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+                .event_spec = us5182d_events,
+                .num_event_specs = ARRAY_SIZE(us5182d_events),
         }
 };
 
@@ -487,11 +526,201 @@ static int us5182d_write_raw(struct iio_dev *indio_dev,
         return -EINVAL;
 }
 
+static int us5182d_setup_prox(struct iio_dev *indio_dev,
+                              enum iio_event_direction dir, u16 val)
+{
+        struct us5182d_data *data = iio_priv(indio_dev);
+
+        if (dir == IIO_EV_DIR_FALLING)
+                return i2c_smbus_write_word_data(data->client,
+                                                 US5182D_REG_PXL_TH, val);
+        else if (dir == IIO_EV_DIR_RISING)
+                return i2c_smbus_write_word_data(data->client,
+                                                 US5182D_REG_PXH_TH, val);
+
+        return 0;
+}
+
+static int us5182d_read_thresh(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)
+{
+        struct us5182d_data *data = iio_priv(indio_dev);
+
+        switch (dir) {
+        case IIO_EV_DIR_RISING:
+                mutex_lock(&data->lock);
+                *val = data->px_high_th;
+                mutex_unlock(&data->lock);
+                break;
+        case IIO_EV_DIR_FALLING:
+                mutex_lock(&data->lock);
+                *val = data->px_low_th;
+                mutex_unlock(&data->lock);
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return IIO_VAL_INT;
+}
+
+static int us5182d_write_thresh(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)
+{
+        struct us5182d_data *data = iio_priv(indio_dev);
+        int ret;
+
+        if (val < 0 || val > USHRT_MAX || val2 != 0)
+                return -EINVAL;
+
+        switch (dir) {
+        case IIO_EV_DIR_RISING:
+                mutex_lock(&data->lock);
+                if (data->rising_en) {
+                        ret = us5182d_setup_prox(indio_dev, dir, val);
+                        if (ret < 0)
+                                goto err;
+                }
+                data->px_high_th = val;
+                mutex_unlock(&data->lock);
+                break;
+        case IIO_EV_DIR_FALLING:
+                mutex_lock(&data->lock);
+                if (data->falling_en) {
+                        ret = us5182d_setup_prox(indio_dev, dir, val);
+                        if (ret < 0)
+                                goto err;
+                }
+                data->px_low_th = val;
+                mutex_unlock(&data->lock);
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+err:
+        mutex_unlock(&data->lock);
+        return ret;
+}
+
+static int us5182d_read_event_config(struct iio_dev *indio_dev,
+        const struct iio_chan_spec *chan, enum iio_event_type type,
+        enum iio_event_direction dir)
+{
+        struct us5182d_data *data = iio_priv(indio_dev);
+        int ret;
+
+        switch (dir) {
+        case IIO_EV_DIR_RISING:
+                mutex_lock(&data->lock);
+                ret = data->rising_en;
+                mutex_unlock(&data->lock);
+                break;
+        case IIO_EV_DIR_FALLING:
+                mutex_lock(&data->lock);
+                ret = data->falling_en;
+                mutex_unlock(&data->lock);
+                break;
+        default:
+                ret = -EINVAL;
+                break;
+        }
+
+        return ret;
+}
+
+static int us5182d_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)
+{
+        struct us5182d_data *data = iio_priv(indio_dev);
+        int ret;
+        u16 new_th;
+
+        mutex_lock(&data->lock);
+
+        switch (dir) {
+        case IIO_EV_DIR_RISING:
+                if (data->rising_en == state) {
+                        mutex_unlock(&data->lock);
+                        return 0;
+                }
+                new_th = US5182D_PXH_TH_DISABLE;
+                if (state) {
+                        data->power_mode = US5182D_CONTINUOUS;
+                        ret = us5182d_set_power_state(data, true);
+                        if (ret < 0)
+                                goto err;
+                        ret = us5182d_px_enable(data);
+                        if (ret < 0)
+                                goto err_poweroff;
+                        new_th = data->px_high_th;
+                }
+                ret = us5182d_setup_prox(indio_dev, dir, new_th);
+                if (ret < 0)
+                        goto err_poweroff;
+                data->rising_en = state;
+                break;
+        case IIO_EV_DIR_FALLING:
+                if (data->falling_en == state) {
+                        mutex_unlock(&data->lock);
+                        return 0;
+                }
+                new_th =  US5182D_PXL_TH_DISABLE;
+                if (state) {
+                        data->power_mode = US5182D_CONTINUOUS;
+                        ret = us5182d_set_power_state(data, true);
+                        if (ret < 0)
+                                goto err;
+                        ret = us5182d_px_enable(data);
+                        if (ret < 0)
+                                goto err_poweroff;
+                        new_th = data->px_low_th;
+                }
+                ret = us5182d_setup_prox(indio_dev, dir, new_th);
+                if (ret < 0)
+                        goto err_poweroff;
+                data->falling_en = state;
+                break;
+        default:
+                ret = -EINVAL;
+                goto err;
+        }
+
+        if (!state) {
+                ret = us5182d_set_power_state(data, false);
+                if (ret < 0)
+                        goto err;
+        }
+
+        if (!data->falling_en && !data->rising_en && !data->default_continuous)
+                data->power_mode = US5182D_ONESHOT;
+
+        mutex_unlock(&data->lock);
+        return 0;
+
+err_poweroff:
+        if (state)
+                us5182d_set_power_state(data, false);
+err:
+        mutex_unlock(&data->lock);
+        return ret;
+}
+
 static const struct iio_info us5182d_info = {
         .driver_module  = THIS_MODULE,
         .read_raw = us5182d_read_raw,
         .write_raw = us5182d_write_raw,
         .attrs = &us5182d_attr_group,
+        .read_event_value = &us5182d_read_thresh,
+        .write_event_value = &us5182d_write_thresh,
+        .read_event_config = &us5182d_read_event_config,
+        .write_event_config = &us5182d_write_event_config,
 };
 
 static int us5182d_reset(struct iio_dev *indio_dev)
@@ -513,6 +742,9 @@ static int us5182d_init(struct iio_dev *indio_dev)
 
         data->opmode = 0;
         data->power_mode = US5182D_CONTINUOUS;
+        data->px_low_th = US5182D_REG_PXL_TH_DEFAULT;
+        data->px_high_th = US5182D_REG_PXH_TH_DEFAULT;
+
         for (i = 0; i < ARRAY_SIZE(us5182d_regvals); i++) {
                 ret = i2c_smbus_write_byte_data(data->client,
                                                 us5182d_regvals[i].reg,
@@ -583,6 +815,33 @@ static int  us5182d_dark_gain_config(struct iio_dev *indio_dev)
                                          US5182D_REG_DARK_AUTO_EN_DEFAULT);
 }
 
+static irqreturn_t us5182d_irq_thread_handler(int irq, void *private)
+{
+        struct iio_dev *indio_dev = private;
+        struct us5182d_data *data = iio_priv(indio_dev);
+        enum iio_event_direction dir;
+        int ret;
+        u64 ev;
+
+        ret = i2c_smbus_read_byte_data(data->client, US5182D_REG_CFG0);
+        if (ret < 0) {
+                dev_err(&data->client->dev, "i2c transfer error in irq\n");
+                return IRQ_HANDLED;
+        }
+
+        dir = ret & US5182D_CFG0_PROX ? IIO_EV_DIR_RISING : IIO_EV_DIR_FALLING;
+        ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 1, IIO_EV_TYPE_THRESH, dir);
+
+        iio_push_event(indio_dev, ev, iio_get_time_ns());
+
+        ret = i2c_smbus_write_byte_data(data->client, US5182D_REG_CFG0,
+                                        ret & ~US5182D_CFG0_PX_IRQ);
+        if (ret < 0)
+                dev_err(&data->client->dev, "i2c transfer error in irq\n");
+
+        return IRQ_HANDLED;
+}
+
 static int us5182d_probe(struct i2c_client *client,
                          const struct i2c_device_id *id)
 {
@@ -614,6 +873,16 @@ static int us5182d_probe(struct i2c_client *client,
                 return (ret < 0) ? ret : -ENODEV;
         }
 
+        if (client->irq > 0) {
+                ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+                                                us5182d_irq_thread_handler,
+                                                IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                                "us5182d-irq", indio_dev);
+                if (ret < 0)
+                        return ret;
+        } else
+                dev_warn(&client->dev, "no valid irq found\n");
+
         us5182d_get_platform_data(indio_dev);
         ret = us5182d_init(indio_dev);
         if (ret < 0)