--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * BU27008 ROHM Colour Sensor
+ *
+ * Copyright (c) 2023, ROHM Semiconductor.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/units.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/iio-gts-helper.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define BU27008_REG_SYSTEM_CONTROL 0x40
+#define BU27008_MASK_SW_RESET BIT(7)
+#define BU27008_MASK_PART_ID GENMASK(5, 0)
+#define BU27008_ID 0x1a
+#define BU27008_REG_MODE_CONTROL1 0x41
+#define BU27008_MASK_MEAS_MODE GENMASK(2, 0)
+#define BU27008_MASK_CHAN_SEL GENMASK(3, 2)
+
+#define BU27008_REG_MODE_CONTROL2 0x42
+#define BU27008_MASK_RGBC_GAIN GENMASK(7, 3)
+#define BU27008_MASK_IR_GAIN_LO GENMASK(2, 0)
+#define BU27008_SHIFT_IR_GAIN 3
+
+#define BU27008_REG_MODE_CONTROL3 0x43
+#define BU27008_MASK_VALID BIT(7)
+#define BU27008_MASK_INT_EN BIT(1)
+#define BU27008_INT_EN BU27008_MASK_INT_EN
+#define BU27008_INT_DIS 0
+#define BU27008_MASK_MEAS_EN BIT(0)
+#define BU27008_MEAS_EN BIT(0)
+#define BU27008_MEAS_DIS 0
+
+#define BU27008_REG_DATA0_LO 0x50
+#define BU27008_REG_DATA1_LO 0x52
+#define BU27008_REG_DATA2_LO 0x54
+#define BU27008_REG_DATA3_LO 0x56
+#define BU27008_REG_DATA3_HI 0x57
+#define BU27008_REG_MANUFACTURER_ID 0x92
+#define BU27008_REG_MAX BU27008_REG_MANUFACTURER_ID
+
+/**
+ * enum bu27008_chan_type - BU27008 channel types
+ * @BU27008_RED: Red channel. Always via data0.
+ * @BU27008_GREEN: Green channel. Always via data1.
+ * @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_NUM_CHANS: Number of channel types.
+ */
+enum bu27008_chan_type {
+ BU27008_RED,
+ BU27008_GREEN,
+ BU27008_BLUE,
+ BU27008_CLEAR,
+ BU27008_IR,
+ BU27008_NUM_CHANS
+};
+
+/**
+ * enum bu27008_chan - BU27008 physical data channel
+ * @BU27008_DATA0: Always red.
+ * @BU27008_DATA1: Always green.
+ * @BU27008_DATA2: Blue or clear.
+ * @BU27008_DATA3: IR or clear.
+ * @BU27008_NUM_HW_CHANS: Number of physical channels
+ */
+enum bu27008_chan {
+ BU27008_DATA0,
+ BU27008_DATA1,
+ BU27008_DATA2,
+ BU27008_DATA3,
+ BU27008_NUM_HW_CHANS
+};
+
+/* We can always measure red and green at same time */
+#define ALWAYS_SCANNABLE (BIT(BU27008_RED) | BIT(BU27008_GREEN))
+
+/* We use these data channel configs. Ensure scan_masks below follow them too */
+#define BU27008_BLUE2_CLEAR3 0x0 /* buffer is R, G, B, C */
+#define BU27008_CLEAR2_IR3 0x1 /* buffer is R, G, C, IR */
+#define BU27008_BLUE2_IR3 0x2 /* buffer is R, G, B, IR */
+
+static const unsigned long bu27008_scan_masks[] = {
+ /* buffer is R, G, B, C */
+ ALWAYS_SCANNABLE | BIT(BU27008_BLUE) | BIT(BU27008_CLEAR),
+ /* buffer is R, G, C, IR */
+ ALWAYS_SCANNABLE | BIT(BU27008_CLEAR) | BIT(BU27008_IR),
+ /* buffer is R, G, B, IR */
+ ALWAYS_SCANNABLE | BIT(BU27008_BLUE) | BIT(BU27008_IR),
+ 0
+};
+
+/*
+ * Available scales with gain 1x - 1024x, timings 55, 100, 200, 400 mS
+ * Time impacts to gain: 1x, 2x, 4x, 8x.
+ *
+ * => Max total gain is HWGAIN * gain by integration time (8 * 1024) = 8192
+ *
+ * Max amplification is (HWGAIN * MAX integration-time multiplier) 1024 * 8
+ * = 8192. With NANO scale we get rid of accuracy loss when we start with the
+ * scale 16.0 for HWGAIN1, INT-TIME 55 mS. This way the nano scale for MAX
+ * total gain 8192 will be 1953125
+ */
+#define BU27008_SCALE_1X 16
+
+/* See the data sheet for the "Gain Setting" table */
+#define BU27008_GSEL_1X 0x00
+#define BU27008_GSEL_4X 0x08
+#define BU27008_GSEL_8X 0x09
+#define BU27008_GSEL_16X 0x0a
+#define BU27008_GSEL_32X 0x0b
+#define BU27008_GSEL_64X 0x0c
+#define BU27008_GSEL_256X 0x18
+#define BU27008_GSEL_512X 0x19
+#define BU27008_GSEL_1024X 0x1a
+
+static const struct iio_gain_sel_pair bu27008_gains[] = {
+ GAIN_SCALE_GAIN(1, BU27008_GSEL_1X),
+ GAIN_SCALE_GAIN(4, BU27008_GSEL_4X),
+ GAIN_SCALE_GAIN(8, BU27008_GSEL_8X),
+ GAIN_SCALE_GAIN(16, BU27008_GSEL_16X),
+ GAIN_SCALE_GAIN(32, BU27008_GSEL_32X),
+ GAIN_SCALE_GAIN(64, BU27008_GSEL_64X),
+ GAIN_SCALE_GAIN(256, BU27008_GSEL_256X),
+ GAIN_SCALE_GAIN(512, BU27008_GSEL_512X),
+ GAIN_SCALE_GAIN(1024, BU27008_GSEL_1024X),
+};
+
+static const struct iio_gain_sel_pair bu27008_gains_ir[] = {
+ GAIN_SCALE_GAIN(2, BU27008_GSEL_1X),
+ GAIN_SCALE_GAIN(4, BU27008_GSEL_4X),
+ GAIN_SCALE_GAIN(8, BU27008_GSEL_8X),
+ GAIN_SCALE_GAIN(16, BU27008_GSEL_16X),
+ GAIN_SCALE_GAIN(32, BU27008_GSEL_32X),
+ GAIN_SCALE_GAIN(64, BU27008_GSEL_64X),
+ GAIN_SCALE_GAIN(256, BU27008_GSEL_256X),
+ GAIN_SCALE_GAIN(512, BU27008_GSEL_512X),
+ GAIN_SCALE_GAIN(1024, BU27008_GSEL_1024X),
+};
+
+#define BU27008_MEAS_MODE_100MS 0x00
+#define BU27008_MEAS_MODE_55MS 0x01
+#define BU27008_MEAS_MODE_200MS 0x02
+#define BU27008_MEAS_MODE_400MS 0x04
+#define BU27008_MEAS_TIME_MAX_MS 400
+
+static const struct iio_itime_sel_mul bu27008_itimes[] = {
+ GAIN_SCALE_ITIME_US(400000, BU27008_MEAS_MODE_400MS, 8),
+ GAIN_SCALE_ITIME_US(200000, BU27008_MEAS_MODE_200MS, 4),
+ GAIN_SCALE_ITIME_US(100000, BU27008_MEAS_MODE_100MS, 2),
+ GAIN_SCALE_ITIME_US(55000, BU27008_MEAS_MODE_55MS, 1),
+};
+
+/*
+ * All the RGBC channels share the same gain.
+ * IR gain can be fine-tuned from the gain set for the RGBC by 2 bit, but this
+ * would yield quite complex gain setting. Especially since not all bit
+ * compinations are supported. And in any case setting GAIN for RGBC will
+ * always also change the IR-gain.
+ *
+ * On top of this, the selector '0' which corresponds to hw-gain 1X on RGBC,
+ * corresponds to gain 2X on IR. Rest of the selctors correspond to same gains
+ * though. This, however, makes it not possible to use shared gain for all
+ * RGBC and IR settings even though they are all changed at the one go.
+ */
+#define BU27008_CHAN(color, data, separate_avail) \
+{ \
+ .type = IIO_INTENSITY, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_LIGHT_##color, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_separate_available = (separate_avail), \
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), \
+ .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME), \
+ .address = BU27008_REG_##data##_LO, \
+ .scan_index = BU27008_##color, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_LE, \
+ }, \
+}
+
+/* For raw reads we always configure DATA3 for CLEAR */
+static const struct iio_chan_spec bu27008_channels[] = {
+ BU27008_CHAN(RED, DATA0, BIT(IIO_CHAN_INFO_SCALE)),
+ BU27008_CHAN(GREEN, DATA1, BIT(IIO_CHAN_INFO_SCALE)),
+ BU27008_CHAN(BLUE, DATA2, BIT(IIO_CHAN_INFO_SCALE)),
+ BU27008_CHAN(CLEAR, DATA2, BIT(IIO_CHAN_INFO_SCALE)),
+ /*
+ * We don't allow setting scale for IR (because of shared gain bits).
+ * Hence we don't advertise available ones either.
+ */
+ BU27008_CHAN(IR, DATA3, 0),
+ IIO_CHAN_SOFT_TIMESTAMP(BU27008_NUM_CHANS),
+};
+
+struct bu27008_data {
+ struct regmap *regmap;
+ struct iio_trigger *trig;
+ struct device *dev;
+ struct iio_gts gts;
+ struct iio_gts gts_ir;
+ int irq;
+
+ /*
+ * Prevent changing gain/time config when scale is read/written.
+ * Similarly, protect the integration_time read/change sequence.
+ * Prevent changing gain/time when data is read.
+ */
+ struct mutex mutex;
+};
+
+static const struct regmap_range bu27008_volatile_ranges[] = {
+ {
+ .range_min = BU27008_REG_SYSTEM_CONTROL, /* SWRESET */
+ .range_max = BU27008_REG_SYSTEM_CONTROL,
+ }, {
+ .range_min = BU27008_REG_MODE_CONTROL3, /* VALID */
+ .range_max = BU27008_REG_MODE_CONTROL3,
+ }, {
+ .range_min = BU27008_REG_DATA0_LO, /* DATA */
+ .range_max = BU27008_REG_DATA3_HI,
+ },
+};
+
+static const struct regmap_access_table bu27008_volatile_regs = {
+ .yes_ranges = &bu27008_volatile_ranges[0],
+ .n_yes_ranges = ARRAY_SIZE(bu27008_volatile_ranges),
+};
+
+static const struct regmap_range bu27008_read_only_ranges[] = {
+ {
+ .range_min = BU27008_REG_DATA0_LO,
+ .range_max = BU27008_REG_DATA3_HI,
+ }, {
+ .range_min = BU27008_REG_MANUFACTURER_ID,
+ .range_max = BU27008_REG_MANUFACTURER_ID,
+ },
+};
+
+static const struct regmap_access_table bu27008_ro_regs = {
+ .no_ranges = &bu27008_read_only_ranges[0],
+ .n_no_ranges = ARRAY_SIZE(bu27008_read_only_ranges),
+};
+
+static const struct regmap_config bu27008_regmap = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = BU27008_REG_MAX,
+ .cache_type = REGCACHE_RBTREE,
+ .volatile_table = &bu27008_volatile_regs,
+ .wr_table = &bu27008_ro_regs,
+ /*
+ * All register writes are serialized by the mutex which protects the
+ * scale setting/getting. This is needed because scale is combined by
+ * gain and integration time settings and we need to ensure those are
+ * not read / written when scale is being computed.
+ *
+ * As a result of this serializing, we don't need regmap locking. Note,
+ * this is not true if we add any configurations which are not
+ * serialized by the mutex and which may need for example a protected
+ * read-modify-write cycle (eg. regmap_update_bits()). Please, revise
+ * this when adding features to the driver.
+ */
+ .disable_locking = true,
+};
+
+#define BU27008_MAX_VALID_RESULT_WAIT_US 50000
+#define BU27008_VALID_RESULT_WAIT_QUANTA_US 1000
+
+static int bu27008_chan_read_data(struct bu27008_data *data, int reg, int *val)
+{
+ int ret, valid;
+ __le16 tmp;
+
+ ret = regmap_read_poll_timeout(data->regmap, BU27008_REG_MODE_CONTROL3,
+ valid, (valid & BU27008_MASK_VALID),
+ BU27008_VALID_RESULT_WAIT_QUANTA_US,
+ BU27008_MAX_VALID_RESULT_WAIT_US);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, reg, &tmp, sizeof(tmp));
+ if (ret)
+ dev_err(data->dev, "Reading channel data failed\n");
+
+ *val = le16_to_cpu(tmp);
+
+ return ret;
+}
+
+static int bu27008_get_gain(struct bu27008_data *data, struct iio_gts *gts, int *gain)
+{
+ int ret, sel;
+
+ ret = regmap_read(data->regmap, BU27008_REG_MODE_CONTROL2, &sel);
+ if (ret)
+ return ret;
+
+ sel = FIELD_GET(BU27008_MASK_RGBC_GAIN, sel);
+
+ ret = iio_gts_find_gain_by_sel(gts, sel);
+ if (ret < 0) {
+ dev_err(data->dev, "unknown gain value 0x%x\n", sel);
+ return ret;
+ }
+
+ *gain = ret;
+
+ return 0;
+}
+
+static int bu27008_write_gain_sel(struct bu27008_data *data, int sel)
+{
+ int regval;
+
+ regval = FIELD_PREP(BU27008_MASK_RGBC_GAIN, sel);
+
+ /*
+ * We do always set also the LOW bits of IR-gain because othervice we
+ * would risk resulting an invalid GAIN register value.
+ *
+ * We could allow setting separate gains for RGBC and IR when the
+ * values were such that HW could support both gain settings.
+ * Eg, when the shared bits were same for both gain values.
+ *
+ * This, however, has a negligible benefit compared to the increased
+ * software complexity when we would need to go through the gains
+ * for both channels separately when the integration time changes.
+ * This would end up with nasty logic for computing gain values for
+ * both channels - and rejecting them if shared bits changed.
+ *
+ * We should then build the logic by guessing what a user prefers.
+ * RGBC or IR gains correctly set while other jumps to odd value?
+ * Maybe look-up a value where both gains are somehow optimized
+ * <what this somehow is, is ATM unknown to us>. Or maybe user would
+ * expect us to reject changes when optimal gains can't be set to both
+ * channels w/given integration time. At best that would result
+ * solution that works well for a very specific subset of
+ * configurations but causes unexpected corner-cases.
+ *
+ * So, we keep it simple. Always set same selector to IR and RGBC.
+ * We disallow setting IR (as I expect that most of the users are
+ * interested in RGBC). This way we can show the user that the scales
+ * for RGBC and IR channels are different (1X Vs 2X with sel 0) while
+ * still keeping the operation deterministic.
+ */
+ regval |= FIELD_PREP(BU27008_MASK_IR_GAIN_LO, sel);
+
+ return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL2,
+ BU27008_MASK_RGBC_GAIN, regval);
+}
+
+static int bu27008_set_gain(struct bu27008_data *data, int gain)
+{
+ int ret;
+
+ ret = iio_gts_find_sel_by_gain(&data->gts, gain);
+ if (ret < 0)
+ return ret;
+
+ return bu27008_write_gain_sel(data, ret);
+}
+
+static int bu27008_get_int_time_sel(struct bu27008_data *data, int *sel)
+{
+ int ret, val;
+
+ ret = regmap_read(data->regmap, BU27008_REG_MODE_CONTROL1, &val);
+ *sel = FIELD_GET(BU27008_MASK_MEAS_MODE, val);
+
+ return ret;
+}
+
+static int bu27008_set_int_time_sel(struct bu27008_data *data, int sel)
+{
+ return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL1,
+ BU27008_MASK_MEAS_MODE, sel);
+}
+
+static int bu27008_get_int_time_us(struct bu27008_data *data)
+{
+ int ret, sel;
+
+ ret = bu27008_get_int_time_sel(data, &sel);
+ if (ret)
+ return ret;
+
+ return iio_gts_find_int_time_by_sel(&data->gts, sel);
+}
+
+static int _bu27008_get_scale(struct bu27008_data *data, bool ir, int *val,
+ int *val2)
+{
+ struct iio_gts *gts;
+ int gain, ret;
+
+ if (ir)
+ gts = &data->gts_ir;
+ else
+ gts = &data->gts;
+
+ ret = bu27008_get_gain(data, gts, &gain);
+ if (ret)
+ return ret;
+
+ ret = bu27008_get_int_time_us(data);
+ if (ret < 0)
+ return ret;
+
+ return iio_gts_get_scale(gts, gain, ret, val, val2);
+}
+
+static int bu27008_get_scale(struct bu27008_data *data, bool ir, int *val,
+ int *val2)
+{
+ int ret;
+
+ mutex_lock(&data->mutex);
+ ret = _bu27008_get_scale(data, ir, val, val2);
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static int bu27008_set_int_time(struct bu27008_data *data, int time)
+{
+ int ret;
+
+ ret = iio_gts_find_sel_by_int_time(&data->gts, time);
+ if (ret < 0)
+ return ret;
+
+ return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL1,
+ BU27008_MASK_MEAS_MODE, ret);
+}
+
+/* Try to change the time so that the scale is maintained */
+static int bu27008_try_set_int_time(struct bu27008_data *data, int int_time_new)
+{
+ int ret, old_time_sel, new_time_sel, old_gain, new_gain;
+
+ mutex_lock(&data->mutex);
+
+ ret = bu27008_get_int_time_sel(data, &old_time_sel);
+ if (ret < 0)
+ goto unlock_out;
+
+ if (!iio_gts_valid_time(&data->gts, int_time_new)) {
+ dev_dbg(data->dev, "Unsupported integration time %u\n",
+ int_time_new);
+
+ ret = -EINVAL;
+ goto unlock_out;
+ }
+
+ /* If we already use requested time, then we're done */
+ new_time_sel = iio_gts_find_sel_by_int_time(&data->gts, int_time_new);
+ if (new_time_sel == old_time_sel)
+ goto unlock_out;
+
+ ret = bu27008_get_gain(data, &data->gts, &old_gain);
+ if (ret)
+ goto unlock_out;
+
+ ret = iio_gts_find_new_gain_sel_by_old_gain_time(&data->gts, old_gain,
+ old_time_sel, new_time_sel, &new_gain);
+ if (ret) {
+ int scale1, scale2;
+ bool ok;
+
+ _bu27008_get_scale(data, false, &scale1, &scale2);
+ dev_dbg(data->dev,
+ "Can't support time %u with current scale %u %u\n",
+ int_time_new, scale1, scale2);
+
+ if (new_gain < 0)
+ goto unlock_out;
+
+ /*
+ * If caller requests for integration time change and we
+ * can't support the scale - then the caller should be
+ * prepared to 'pick up the pieces and deal with the
+ * fact that the scale changed'.
+ */
+ ret = iio_find_closest_gain_low(&data->gts, new_gain, &ok);
+ if (!ok)
+ dev_dbg(data->dev, "optimal gain out of range\n");
+
+ if (ret < 0) {
+ dev_dbg(data->dev,
+ "Total gain increase. Risk of saturation");
+ ret = iio_gts_get_min_gain(&data->gts);
+ if (ret < 0)
+ goto unlock_out;
+ }
+ new_gain = ret;
+ dev_dbg(data->dev, "scale changed, new gain %u\n", new_gain);
+ }
+
+ ret = bu27008_set_gain(data, new_gain);
+ if (ret)
+ goto unlock_out;
+
+ ret = bu27008_set_int_time(data, int_time_new);
+
+unlock_out:
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static int bu27008_meas_set(struct bu27008_data *data, int state)
+{
+ return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL3,
+ BU27008_MASK_MEAS_EN, state);
+}
+
+static int bu27008_chan_cfg(struct bu27008_data *data,
+ struct iio_chan_spec const *chan)
+{
+ int chan_sel;
+
+ if (chan->scan_index == BU27008_BLUE)
+ chan_sel = BU27008_BLUE2_CLEAR3;
+ else
+ chan_sel = BU27008_CLEAR2_IR3;
+
+ chan_sel = FIELD_PREP(BU27008_MASK_CHAN_SEL, chan_sel);
+
+ return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL3,
+ BU27008_MASK_CHAN_SEL, chan_sel);
+}
+
+static int bu27008_read_one(struct bu27008_data *data, struct iio_dev *idev,
+ struct iio_chan_spec const *chan, int *val, int *val2)
+{
+ int ret, int_time;
+
+ ret = bu27008_chan_cfg(data, chan);
+ if (ret)
+ return ret;
+
+ ret = bu27008_meas_set(data, BU27008_MEAS_EN);
+ if (ret)
+ return ret;
+
+ ret = bu27008_get_int_time_us(data);
+ if (ret < 0)
+ int_time = BU27008_MEAS_TIME_MAX_MS;
+ else
+ int_time = ret / USEC_PER_MSEC;
+
+ msleep(int_time);
+
+ ret = bu27008_chan_read_data(data, chan->address, val);
+ if (!ret)
+ ret = IIO_VAL_INT;
+
+ if (bu27008_meas_set(data, BU27008_MEAS_DIS))
+ dev_warn(data->dev, "measurement disabling failed\n");
+
+ return ret;
+}
+
+static int bu27008_read_raw(struct iio_dev *idev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct bu27008_data *data = iio_priv(idev);
+ int busy, ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ busy = iio_device_claim_direct_mode(idev);
+ if (busy)
+ return -EBUSY;
+
+ mutex_lock(&data->mutex);
+ ret = bu27008_read_one(data, idev, chan, val, val2);
+ mutex_unlock(&data->mutex);
+
+ iio_device_release_direct_mode(idev);
+
+ return ret;
+
+ case IIO_CHAN_INFO_SCALE:
+ ret = bu27008_get_scale(data, chan->scan_index == BU27008_IR,
+ val, val2);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT_PLUS_NANO;
+
+ case IIO_CHAN_INFO_INT_TIME:
+ ret = bu27008_get_int_time_us(data);
+ if (ret < 0)
+ return ret;
+
+ *val = 0;
+ *val2 = ret;
+
+ return IIO_VAL_INT_PLUS_MICRO;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+/* Called if the new scale could not be supported with existing int-time */
+static int bu27008_try_find_new_time_gain(struct bu27008_data *data, int val,
+ int val2, int *gain_sel)
+{
+ int i, ret, new_time_sel;
+
+ for (i = 0; i < data->gts.num_itime; i++) {
+ new_time_sel = data->gts.itime_table[i].sel;
+ ret = iio_gts_find_gain_sel_for_scale_using_time(&data->gts,
+ new_time_sel, val, val2 * 1000, gain_sel);
+ if (!ret)
+ break;
+ }
+ if (i == data->gts.num_itime) {
+ dev_err(data->dev, "Can't support scale %u %u\n", val, val2);
+
+ return -EINVAL;
+ }
+
+ return bu27008_set_int_time_sel(data, new_time_sel);
+}
+
+static int bu27008_set_scale(struct bu27008_data *data,
+ struct iio_chan_spec const *chan,
+ int val, int val2)
+{
+ int ret, gain_sel, time_sel;
+
+ if (chan->scan_index == BU27008_IR)
+ return -EINVAL;
+
+ mutex_lock(&data->mutex);
+
+ ret = bu27008_get_int_time_sel(data, &time_sel);
+ if (ret < 0)
+ goto unlock_out;
+
+ ret = iio_gts_find_gain_sel_for_scale_using_time(&data->gts, time_sel,
+ val, val2 * 1000, &gain_sel);
+ if (ret) {
+ ret = bu27008_try_find_new_time_gain(data, val, val2, &gain_sel);
+ if (ret)
+ goto unlock_out;
+
+ }
+ ret = bu27008_write_gain_sel(data, gain_sel);
+
+unlock_out:
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static int bu27008_write_raw(struct iio_dev *idev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct bu27008_data *data = iio_priv(idev);
+ int ret;
+
+ /*
+ * Do not allow changing scale when measurement is ongoing as doing so
+ * could make values in the buffer inconsistent.
+ */
+ ret = iio_device_claim_direct_mode(idev);
+ if (ret)
+ return ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ ret = bu27008_set_scale(data, chan, val, val2);
+ break;
+ case IIO_CHAN_INFO_INT_TIME:
+ if (val) {
+ ret = -EINVAL;
+ break;
+ }
+ ret = bu27008_try_set_int_time(data, val2);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ iio_device_release_direct_mode(idev);
+
+ return ret;
+}
+
+static int bu27008_read_avail(struct iio_dev *idev,
+ struct iio_chan_spec const *chan, const int **vals,
+ int *type, int *length, long mask)
+{
+ struct bu27008_data *data = iio_priv(idev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_INT_TIME:
+ return iio_gts_avail_times(&data->gts, vals, type, length);
+ case IIO_CHAN_INFO_SCALE:
+ if (chan->channel2 == IIO_MOD_LIGHT_IR)
+ return iio_gts_all_avail_scales(&data->gts_ir, vals,
+ type, length);
+ return iio_gts_all_avail_scales(&data->gts, vals, type, length);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int bu27008_update_scan_mode(struct iio_dev *idev,
+ const unsigned long *scan_mask)
+{
+ struct bu27008_data *data = iio_priv(idev);
+ int chan_sel;
+
+ /* Configure channel selection */
+ if (test_bit(BU27008_BLUE, idev->active_scan_mask)) {
+ if (test_bit(BU27008_CLEAR, idev->active_scan_mask))
+ chan_sel = BU27008_BLUE2_CLEAR3;
+ else
+ chan_sel = BU27008_BLUE2_IR3;
+ } else {
+ chan_sel = BU27008_CLEAR2_IR3;
+ }
+
+ chan_sel = FIELD_PREP(BU27008_MASK_CHAN_SEL, chan_sel);
+
+ return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL3,
+ BU27008_MASK_CHAN_SEL, chan_sel);
+}
+
+static const struct iio_info bu27008_info = {
+ .read_raw = &bu27008_read_raw,
+ .write_raw = &bu27008_write_raw,
+ .read_avail = &bu27008_read_avail,
+ .update_scan_mode = bu27008_update_scan_mode,
+ .validate_trigger = iio_validate_own_trigger,
+};
+
+static int bu27008_chip_init(struct bu27008_data *data)
+{
+ int ret;
+
+ ret = regmap_write_bits(data->regmap, BU27008_REG_SYSTEM_CONTROL,
+ BU27008_MASK_SW_RESET, BU27008_MASK_SW_RESET);
+ if (ret)
+ return dev_err_probe(data->dev, ret, "Sensor reset failed\n");
+
+ /*
+ * The data-sheet does not tell how long performing the IC reset takes.
+ * However, the data-sheet says the minimum time it takes the IC to be
+ * able to take inputs after power is applied, is 100 uS. I'd assume
+ * > 1 mS is enough.
+ */
+ msleep(1);
+
+ ret = regmap_reinit_cache(data->regmap, &bu27008_regmap);
+ if (ret)
+ dev_err(data->dev, "Failed to reinit reg cache\n");
+
+ return ret;
+}
+
+static int bu27008_set_drdy_irq(struct bu27008_data *data, int state)
+{
+ return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL3,
+ BU27008_MASK_INT_EN, state);
+}
+
+static int bu27008_trigger_set_state(struct iio_trigger *trig,
+ bool state)
+{
+ struct bu27008_data *data = iio_trigger_get_drvdata(trig);
+ int ret;
+
+ if (state)
+ ret = bu27008_set_drdy_irq(data, BU27008_INT_EN);
+ else
+ ret = bu27008_set_drdy_irq(data, BU27008_INT_DIS);
+ if (ret)
+ dev_err(data->dev, "Failed to set trigger state\n");
+
+ return ret;
+}
+
+static void bu27008_trigger_reenable(struct iio_trigger *trig)
+{
+ struct bu27008_data *data = iio_trigger_get_drvdata(trig);
+
+ enable_irq(data->irq);
+}
+
+static const struct iio_trigger_ops bu27008_trigger_ops = {
+ .set_trigger_state = bu27008_trigger_set_state,
+ .reenable = bu27008_trigger_reenable,
+};
+
+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;
+ int ret, dummy;
+
+ memset(&raw, 0, sizeof(raw));
+
+ /*
+ * After some measurements, it seems reading the
+ * BU27008_REG_MODE_CONTROL3 debounces the IRQ line
+ */
+ ret = regmap_read(data->regmap, BU27008_REG_MODE_CONTROL3, &dummy);
+ if (ret < 0)
+ goto err_read;
+
+ ret = regmap_bulk_read(data->regmap, BU27008_REG_DATA0_LO, &raw.chan,
+ sizeof(raw.chan));
+ if (ret < 0)
+ goto err_read;
+
+ iio_push_to_buffers_with_timestamp(idev, &raw, pf->timestamp);
+err_read:
+ iio_trigger_notify_done(idev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static int bu27008_buffer_preenable(struct iio_dev *idev)
+{
+ struct bu27008_data *data = iio_priv(idev);
+
+ return bu27008_meas_set(data, BU27008_MEAS_EN);
+}
+
+static int bu27008_buffer_postdisable(struct iio_dev *idev)
+{
+ struct bu27008_data *data = iio_priv(idev);
+
+ return bu27008_meas_set(data, BU27008_MEAS_DIS);
+}
+
+static const struct iio_buffer_setup_ops bu27008_buffer_ops = {
+ .preenable = bu27008_buffer_preenable,
+ .postdisable = bu27008_buffer_postdisable,
+};
+
+static irqreturn_t bu27008_data_rdy_poll(int irq, void *private)
+{
+ /*
+ * The BU27008 keeps IRQ asserted until we read the VALID bit from
+ * a register. We need to keep the IRQ disabled until then.
+ */
+ disable_irq_nosync(irq);
+ iio_trigger_poll(private);
+
+ return IRQ_HANDLED;
+}
+
+static int bu27008_setup_trigger(struct bu27008_data *data, struct iio_dev *idev)
+{
+ struct iio_trigger *itrig;
+ char *name;
+ int ret;
+
+ ret = devm_iio_triggered_buffer_setup(data->dev, idev,
+ &iio_pollfunc_store_time,
+ bu27008_trigger_handler,
+ &bu27008_buffer_ops);
+ if (ret)
+ return dev_err_probe(data->dev, ret,
+ "iio_triggered_buffer_setup_ext FAIL\n");
+
+ itrig = devm_iio_trigger_alloc(data->dev, "%sdata-rdy-dev%d",
+ idev->name, iio_device_id(idev));
+ if (!itrig)
+ return -ENOMEM;
+
+ data->trig = itrig;
+
+ itrig->ops = &bu27008_trigger_ops;
+ iio_trigger_set_drvdata(itrig, data);
+
+ name = devm_kasprintf(data->dev, GFP_KERNEL, "%s-bu27008",
+ dev_name(data->dev));
+
+ ret = devm_request_irq(data->dev, data->irq,
+ &bu27008_data_rdy_poll,
+ 0, name, itrig);
+ if (ret)
+ return dev_err_probe(data->dev, ret, "Could not request IRQ\n");
+
+ ret = devm_iio_trigger_register(data->dev, itrig);
+ if (ret)
+ return dev_err_probe(data->dev, ret,
+ "Trigger registration failed\n");
+
+ /* set default trigger */
+ idev->trig = iio_trigger_get(itrig);
+
+ return 0;
+}
+
+static int bu27008_probe(struct i2c_client *i2c)
+{
+ struct device *dev = &i2c->dev;
+ struct bu27008_data *data;
+ struct regmap *regmap;
+ unsigned int part_id, reg;
+ struct iio_dev *idev;
+ int ret;
+
+ regmap = devm_regmap_init_i2c(i2c, &bu27008_regmap);
+ if (IS_ERR(regmap))
+ return dev_err_probe(dev, PTR_ERR(regmap),
+ "Failed to initialize Regmap\n");
+
+ idev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!idev)
+ return -ENOMEM;
+
+ ret = devm_regulator_get_enable(dev, "vdd");
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to get regulator\n");
+
+ data = iio_priv(idev);
+
+ ret = regmap_read(regmap, BU27008_REG_SYSTEM_CONTROL, ®);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to access sensor\n");
+
+ part_id = FIELD_GET(BU27008_MASK_PART_ID, reg);
+
+ if (part_id != BU27008_ID)
+ dev_warn(dev, "unknown device 0x%x\n", part_id);
+
+ ret = devm_iio_init_iio_gts(dev, BU27008_SCALE_1X, 0, bu27008_gains,
+ ARRAY_SIZE(bu27008_gains), bu27008_itimes,
+ ARRAY_SIZE(bu27008_itimes), &data->gts);
+ if (ret)
+ return ret;
+
+ ret = devm_iio_init_iio_gts(dev, BU27008_SCALE_1X, 0, bu27008_gains_ir,
+ ARRAY_SIZE(bu27008_gains_ir), bu27008_itimes,
+ ARRAY_SIZE(bu27008_itimes), &data->gts_ir);
+ if (ret)
+ return ret;
+
+ mutex_init(&data->mutex);
+ data->regmap = regmap;
+ data->dev = dev;
+ data->irq = i2c->irq;
+
+ idev->channels = bu27008_channels;
+ idev->num_channels = ARRAY_SIZE(bu27008_channels);
+ idev->name = "bu27008";
+ idev->info = &bu27008_info;
+ idev->modes = INDIO_DIRECT_MODE;
+ idev->available_scan_masks = bu27008_scan_masks;
+
+ ret = bu27008_chip_init(data);
+ if (ret)
+ return ret;
+
+ if (i2c->irq) {
+ ret = bu27008_setup_trigger(data, idev);
+ if (ret)
+ return ret;
+ } else {
+ dev_info(dev, "No IRQ, buffered mode disabled\n");
+ }
+
+ ret = devm_iio_device_register(dev, idev);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Unable to register iio device\n");
+
+ return 0;
+}
+
+static const struct of_device_id bu27008_of_match[] = {
+ { .compatible = "rohm,bu27008" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, bu27008_of_match);
+
+static struct i2c_driver bu27008_i2c_driver = {
+ .driver = {
+ .name = "bu27008",
+ .of_match_table = bu27008_of_match,
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+ .probe = bu27008_probe,
+};
+module_i2c_driver(bu27008_i2c_driver);
+
+MODULE_DESCRIPTION("ROHM BU27008 colour sensor driver");
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_GTS_HELPER);
projects / linux.git / commitdiff