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Diffstat (limited to 'drivers/iio/light/rohm-bu27008.c')
-rw-r--r--drivers/iio/light/rohm-bu27008.c201
1 files changed, 196 insertions, 5 deletions
diff --git a/drivers/iio/light/rohm-bu27008.c b/drivers/iio/light/rohm-bu27008.c
index 6a6d778050..0f010eff19 100644
--- a/drivers/iio/light/rohm-bu27008.c
+++ b/drivers/iio/light/rohm-bu27008.c
@@ -130,6 +130,7 @@
* @BU27008_BLUE: Blue channel. Via data2 (when used).
* @BU27008_CLEAR: Clear channel. Via data2 or data3 (when used).
* @BU27008_IR: IR channel. Via data3 (when used).
+ * @BU27008_LUX: Illuminance channel, computed using RGB and IR.
* @BU27008_NUM_CHANS: Number of channel types.
*/
enum bu27008_chan_type {
@@ -138,6 +139,7 @@ enum bu27008_chan_type {
BU27008_BLUE,
BU27008_CLEAR,
BU27008_IR,
+ BU27008_LUX,
BU27008_NUM_CHANS
};
@@ -172,6 +174,8 @@ static const unsigned long bu27008_scan_masks[] = {
ALWAYS_SCANNABLE | BIT(BU27008_CLEAR) | BIT(BU27008_IR),
/* buffer is R, G, B, IR */
ALWAYS_SCANNABLE | BIT(BU27008_BLUE) | BIT(BU27008_IR),
+ /* buffer is R, G, B, IR, LUX */
+ ALWAYS_SCANNABLE | BIT(BU27008_BLUE) | BIT(BU27008_IR) | BIT(BU27008_LUX),
0
};
@@ -331,6 +335,19 @@ static const struct iio_chan_spec bu27008_channels[] = {
* Hence we don't advertise available ones either.
*/
BU27008_CHAN(IR, DATA3, 0),
+ {
+ .type = IIO_LIGHT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .channel = BU27008_LUX,
+ .scan_index = BU27008_LUX,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 64,
+ .storagebits = 64,
+ .endianness = IIO_CPU,
+ },
+ },
IIO_CHAN_SOFT_TIMESTAMP(BU27008_NUM_CHANS),
};
@@ -1004,6 +1021,169 @@ static int bu27008_read_one(struct bu27008_data *data, struct iio_dev *idev,
return ret;
}
+#define BU27008_LUX_DATA_RED 0
+#define BU27008_LUX_DATA_GREEN 1
+#define BU27008_LUX_DATA_BLUE 2
+#define BU27008_LUX_DATA_IR 3
+#define LUX_DATA_SIZE (BU27008_NUM_HW_CHANS * sizeof(__le16))
+
+static int bu27008_read_lux_chans(struct bu27008_data *data, unsigned int time,
+ __le16 *chan_data)
+{
+ int ret, chan_sel, tmpret, valid;
+
+ chan_sel = BU27008_BLUE2_IR3 << (ffs(data->cd->chan_sel_mask) - 1);
+
+ ret = regmap_update_bits(data->regmap, data->cd->chan_sel_reg,
+ data->cd->chan_sel_mask, chan_sel);
+ if (ret)
+ return ret;
+
+ ret = bu27008_meas_set(data, true);
+ if (ret)
+ return ret;
+
+ msleep(time / USEC_PER_MSEC);
+
+ ret = regmap_read_poll_timeout(data->regmap, data->cd->valid_reg,
+ valid, (valid & BU27008_MASK_VALID),
+ BU27008_VALID_RESULT_WAIT_QUANTA_US,
+ BU27008_MAX_VALID_RESULT_WAIT_US);
+ if (ret)
+ goto out;
+
+ ret = regmap_bulk_read(data->regmap, BU27008_REG_DATA0_LO, chan_data,
+ LUX_DATA_SIZE);
+ if (ret)
+ goto out;
+out:
+ tmpret = bu27008_meas_set(data, false);
+ if (tmpret)
+ dev_warn(data->dev, "Stopping measurement failed\n");
+
+ return ret;
+}
+
+/*
+ * Following equation for computing lux out of register values was given by
+ * ROHM HW colleagues;
+ *
+ * Red = RedData*1024 / Gain * 20 / meas_mode
+ * Green = GreenData* 1024 / Gain * 20 / meas_mode
+ * Blue = BlueData* 1024 / Gain * 20 / meas_mode
+ * IR = IrData* 1024 / Gain * 20 / meas_mode
+ *
+ * where meas_mode is the integration time in mS / 10
+ *
+ * IRratio = (IR > 0.18 * Green) ? 0 : 1
+ *
+ * Lx = max(c1*Red + c2*Green + c3*Blue,0)
+ *
+ * for
+ * IRratio 0: c1 = -0.00002237, c2 = 0.0003219, c3 = -0.000120371
+ * IRratio 1: c1 = -0.00001074, c2 = 0.000305415, c3 = -0.000129367
+ */
+
+/*
+ * The max chan data is 0xffff. When we multiply it by 1024 * 20, we'll get
+ * 0x4FFFB000 which still fits in 32-bit integer. This won't overflow.
+ */
+#define NORM_CHAN_DATA_FOR_LX_CALC(chan, gain, time) (le16_to_cpu(chan) * \
+ 1024 * 20 / (gain) / (time))
+static u64 bu27008_calc_nlux(struct bu27008_data *data, __le16 *lux_data,
+ unsigned int gain, unsigned int gain_ir, unsigned int time)
+{
+ unsigned int red, green, blue, ir;
+ s64 c1, c2, c3, nlux;
+
+ time /= 10000;
+ ir = NORM_CHAN_DATA_FOR_LX_CALC(lux_data[BU27008_LUX_DATA_IR], gain_ir, time);
+ red = NORM_CHAN_DATA_FOR_LX_CALC(lux_data[BU27008_LUX_DATA_RED], gain, time);
+ green = NORM_CHAN_DATA_FOR_LX_CALC(lux_data[BU27008_LUX_DATA_GREEN], gain, time);
+ blue = NORM_CHAN_DATA_FOR_LX_CALC(lux_data[BU27008_LUX_DATA_BLUE], gain, time);
+
+ if ((u64)ir * 100LLU > (u64)green * 18LLU) {
+ c1 = -22370;
+ c2 = 321900;
+ c3 = -120371;
+ } else {
+ c1 = -10740;
+ c2 = 305415;
+ c3 = -129367;
+ }
+ nlux = c1 * red + c2 * green + c3 * blue;
+
+ return max_t(s64, 0, nlux);
+}
+
+static int bu27008_get_time_n_gains(struct bu27008_data *data,
+ unsigned int *gain, unsigned int *gain_ir, unsigned int *time)
+{
+ int ret;
+
+ ret = bu27008_get_gain(data, &data->gts, gain);
+ if (ret < 0)
+ return ret;
+
+ ret = bu27008_get_gain(data, &data->gts_ir, gain_ir);
+ if (ret < 0)
+ return ret;
+
+ ret = bu27008_get_int_time_us(data);
+ if (ret < 0)
+ return ret;
+
+ /* Max integration time is 400000. Fits in signed int. */
+ *time = ret;
+
+ return 0;
+}
+
+struct bu27008_buf {
+ __le16 chan[BU27008_NUM_HW_CHANS];
+ u64 lux __aligned(8);
+ s64 ts __aligned(8);
+};
+
+static int bu27008_buffer_fill_lux(struct bu27008_data *data,
+ struct bu27008_buf *raw)
+{
+ unsigned int gain, gain_ir, time;
+ int ret;
+
+ ret = bu27008_get_time_n_gains(data, &gain, &gain_ir, &time);
+ if (ret)
+ return ret;
+
+ raw->lux = bu27008_calc_nlux(data, raw->chan, gain, gain_ir, time);
+
+ return 0;
+}
+
+static int bu27008_read_lux(struct bu27008_data *data, struct iio_dev *idev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2)
+{
+ __le16 lux_data[BU27008_NUM_HW_CHANS];
+ unsigned int gain, gain_ir, time;
+ u64 nlux;
+ int ret;
+
+ ret = bu27008_get_time_n_gains(data, &gain, &gain_ir, &time);
+ if (ret)
+ return ret;
+
+ ret = bu27008_read_lux_chans(data, time, lux_data);
+ if (ret)
+ return ret;
+
+ nlux = bu27008_calc_nlux(data, lux_data, gain, gain_ir, time);
+ *val = (int)nlux;
+ *val2 = nlux >> 32LLU;
+
+ return IIO_VAL_INT_64;
+}
+
static int bu27008_read_raw(struct iio_dev *idev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
@@ -1018,7 +1198,10 @@ static int bu27008_read_raw(struct iio_dev *idev,
return -EBUSY;
mutex_lock(&data->mutex);
- ret = bu27008_read_one(data, idev, chan, val, val2);
+ if (chan->type == IIO_LIGHT)
+ ret = bu27008_read_lux(data, idev, chan, val, val2);
+ else
+ ret = bu27008_read_one(data, idev, chan, val, val2);
mutex_unlock(&data->mutex);
iio_device_release_direct_mode(idev);
@@ -1026,6 +1209,11 @@ static int bu27008_read_raw(struct iio_dev *idev,
return ret;
case IIO_CHAN_INFO_SCALE:
+ if (chan->type == IIO_LIGHT) {
+ *val = 0;
+ *val2 = 1;
+ return IIO_VAL_INT_PLUS_NANO;
+ }
ret = bu27008_get_scale(data, chan->scan_index == BU27008_IR,
val, val2);
if (ret)
@@ -1236,10 +1424,7 @@ static irqreturn_t bu27008_trigger_handler(int irq, void *p)
struct iio_poll_func *pf = p;
struct iio_dev *idev = pf->indio_dev;
struct bu27008_data *data = iio_priv(idev);
- struct {
- __le16 chan[BU27008_NUM_HW_CHANS];
- s64 ts __aligned(8);
- } raw;
+ struct bu27008_buf raw;
int ret, dummy;
memset(&raw, 0, sizeof(raw));
@@ -1257,6 +1442,12 @@ static irqreturn_t bu27008_trigger_handler(int irq, void *p)
if (ret < 0)
goto err_read;
+ if (test_bit(BU27008_LUX, idev->active_scan_mask)) {
+ ret = bu27008_buffer_fill_lux(data, &raw);
+ if (ret)
+ goto err_read;
+ }
+
iio_push_to_buffers_with_timestamp(idev, &raw, pf->timestamp);
err_read:
iio_trigger_notify_done(idev->trig);