diff --git a/drivers/iio/light/rohm-bu27008.c b/drivers/iio/light/rohm-bu27008.c index 6a6d77805091..0f010eff1981 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);