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Date:   Tue, 13 Jun 2023 13:20:07 +0300
From:   Matti Vaittinen <mazziesaccount@gmail.com>
To:     Matti Vaittinen <mazziesaccount@gmail.com>,
        Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Cc:     Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Matti Vaittinen <mazziesaccount@gmail.com>,
        linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] iio: light: bu27008: add chip info
Message-ID: <e898bb74afdbc9aa030932e82c36b4ce6d13bab7.1686651445.git.mazziesaccount@gmail.com>
References: <cover.1686650184.git.mazziesaccount@gmail.com>
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The ROHM BU27010 RGB + flickering sensor is in many regards similar to
the BU27008. Prepare for adding support for BU27010 by allowing
chip-specific properties to be brought from the of_device_id data.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
 drivers/iio/light/rohm-bu27008.c | 185 +++++++++++++++++++++++--------
 1 file changed, 138 insertions(+), 47 deletions(-)

diff --git a/drivers/iio/light/rohm-bu27008.c b/drivers/iio/light/rohm-bu27=
008.c
index b50bf8973d9a..8c7f6f20a523 100644
--- a/drivers/iio/light/rohm-bu27008.c
+++ b/drivers/iio/light/rohm-bu27008.c
@@ -211,7 +211,33 @@ static const struct iio_chan_spec bu27008_channels[] =
=3D {
 	IIO_CHAN_SOFT_TIMESTAMP(BU27008_NUM_CHANS),
 };
=20
+struct bu27008_data;
+
+struct bu27_chip_data {
+	const char *name;
+	int (*chip_init)(struct bu27008_data *data);
+	int (*get_gain_sel)(struct bu27008_data *data, int *sel);
+	int (*write_gain_sel)(struct bu27008_data *data, int sel);
+	const struct regmap_config *regmap_cfg;
+	const struct iio_gain_sel_pair *gains;
+	const struct iio_gain_sel_pair *gains_ir;
+	int num_gains;
+	int num_gains_ir;
+	int scale1x;
+
+	int drdy_en_reg;
+	int drdy_en_mask;
+	int meas_en_reg;
+	int meas_en_mask;
+	int valid_reg;
+	int chan_sel_reg;
+	int chan_sel_mask;
+	int int_time_mask;
+	u8 part_id;
+};
+
 struct bu27008_data {
+	const struct bu27_chip_data *cd;
 	struct regmap *regmap;
 	struct iio_trigger *trig;
 	struct device *dev;
@@ -282,6 +308,32 @@ static const struct regmap_config bu27008_regmap =3D {
 	.disable_locking =3D true,
 };
=20
+static int bu27008_chip_init(struct bu27008_data *data);
+static int bu27008_write_gain_sel(struct bu27008_data *data, int sel);
+static int bu27008_get_gain_sel(struct bu27008_data *data, int *sel);
+
+static const struct bu27_chip_data bu27008_chip =3D {
+	.name =3D "bu27008",
+	.chip_init =3D bu27008_chip_init,
+	.scale1x =3D BU27008_SCALE_1X,
+	.get_gain_sel =3D bu27008_get_gain_sel,
+	.write_gain_sel =3D bu27008_write_gain_sel,
+	.part_id =3D BU27008_ID,
+	.regmap_cfg =3D &bu27008_regmap,
+	.drdy_en_reg =3D BU27008_REG_MODE_CONTROL3,
+	.drdy_en_mask =3D BU27008_MASK_INT_EN,
+	.valid_reg =3D BU27008_REG_MODE_CONTROL3,
+	.meas_en_reg =3D BU27008_REG_MODE_CONTROL3,
+	.meas_en_mask =3D BU27008_MASK_MEAS_EN,
+	.chan_sel_reg =3D BU27008_REG_MODE_CONTROL3,
+	.chan_sel_mask =3D BU27008_MASK_CHAN_SEL,
+	.int_time_mask =3D BU27008_MASK_MEAS_MODE,
+	.gains =3D &bu27008_gains[0],
+	.num_gains =3D ARRAY_SIZE(bu27008_gains),
+	.gains_ir =3D &bu27008_gains_ir[0],
+	.num_gains_ir =3D ARRAY_SIZE(bu27008_gains_ir),
+};
+
 #define BU27008_MAX_VALID_RESULT_WAIT_US	50000
 #define BU27008_VALID_RESULT_WAIT_QUANTA_US	1000
=20
@@ -290,7 +342,7 @@ static int bu27008_chan_read_data(struct bu27008_data *=
data, int reg, int *val)
 	int ret, valid;
 	__le16 tmp;
=20
-	ret =3D regmap_read_poll_timeout(data->regmap, BU27008_REG_MODE_CONTROL3,
+	ret =3D 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);
@@ -306,16 +358,40 @@ static int bu27008_chan_read_data(struct bu27008_data=
 *data, int reg, int *val)
 	return ret;
 }
=20
+static int bu27008_get_gain_sel(struct bu27008_data *data, int *sel)
+{
+	int ret;
+
+	/*
+	 * If we always "lock" the gain selectors for all channels to prevent
+	 * unsupported configs, then it does not matter which channel is used
+	 * we can just return selector from any of them.
+	 *
+	 * This, however is not true if we decide to support only 4X and 16X
+	 * and then individual gains for channels. Currently this is not the
+	 * case.
+	 *
+	 * If we some day decide to support individual gains, then we need to
+	 * have channel information here.
+	 */
+
+	ret =3D regmap_read(data->regmap, BU27008_REG_MODE_CONTROL2, sel);
+	if (ret)
+		return ret;
+
+	*sel =3D FIELD_GET(BU27008_MASK_RGBC_GAIN, *sel);
+
+	return 0;
+}
+
 static int bu27008_get_gain(struct bu27008_data *data, struct iio_gts *gts=
, int *gain)
 {
 	int ret, sel;
=20
-	ret =3D regmap_read(data->regmap, BU27008_REG_MODE_CONTROL2, &sel);
+	ret =3D bu27008_get_gain_sel(data, &sel);
 	if (ret)
 		return ret;
=20
-	sel =3D FIELD_GET(BU27008_MASK_RGBC_GAIN, sel);
-
 	ret =3D iio_gts_find_gain_by_sel(gts, sel);
 	if (ret < 0) {
 		dev_err(data->dev, "unknown gain value 0x%x\n", sel);
@@ -384,15 +460,21 @@ static int bu27008_get_int_time_sel(struct bu27008_da=
ta *data, int *sel)
 	int ret, val;
=20
 	ret =3D regmap_read(data->regmap, BU27008_REG_MODE_CONTROL1, &val);
-	*sel =3D FIELD_GET(BU27008_MASK_MEAS_MODE, val);
+
+	val &=3D data->cd->int_time_mask;
+	val >>=3D ffs(data->cd->int_time_mask) - 1;
+
+	*sel =3D val;
=20
 	return ret;
 }
=20
 static int bu27008_set_int_time_sel(struct bu27008_data *data, int sel)
 {
+	sel <<=3D ffs(data->cd->int_time_mask) - 1;
+
 	return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL1,
-				  BU27008_MASK_MEAS_MODE, sel);
+				  data->cd->int_time_mask, sel);
 }
=20
 static int bu27008_get_int_time_us(struct bu27008_data *data)
@@ -448,8 +530,7 @@ static int bu27008_set_int_time(struct bu27008_data *da=
ta, int time)
 	if (ret < 0)
 		return ret;
=20
-	return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL1,
-				  BU27008_MASK_MEAS_MODE, ret);
+	return bu27008_set_int_time_sel(data, ret);
 }
=20
 /* Try to change the time so that the scale is maintained */
@@ -527,10 +608,13 @@ static int bu27008_try_set_int_time(struct bu27008_da=
ta *data, int int_time_new)
 	return ret;
 }
=20
-static int bu27008_meas_set(struct bu27008_data *data, int state)
+static int bu27008_meas_set(struct bu27008_data *data, bool enable)
 {
-	return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL3,
-				  BU27008_MASK_MEAS_EN, state);
+	if (enable)
+		return regmap_set_bits(data->regmap, data->cd->meas_en_reg,
+				       data->cd->meas_en_mask);
+	return regmap_clear_bits(data->regmap, data->cd->meas_en_reg,
+				 data->cd->meas_en_mask);
 }
=20
 static int bu27008_chan_cfg(struct bu27008_data *data,
@@ -543,9 +627,15 @@ static int bu27008_chan_cfg(struct bu27008_data *data,
 	else
 		chan_sel =3D BU27008_CLEAR2_IR3;
=20
-	chan_sel =3D FIELD_PREP(BU27008_MASK_CHAN_SEL, chan_sel);
+	/*
+	 * prepare bitfield for channel sel. The FIELD_PREP works only when
+	 * mask is constant. In our case the mask is assigned based on the
+	 * chip type. Hence the open-coded FIELD_PREP here. We don't bother
+	 * zeroing the irrelevant bits though - update_bits takes care of that.
+	 */
+	chan_sel <<=3D ffs(data->cd->chan_sel_mask) - 1;
=20
-	return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL3,
+	return regmap_update_bits(data->regmap, data->cd->chan_sel_reg,
 				  BU27008_MASK_CHAN_SEL, chan_sel);
 }
=20
@@ -558,7 +648,7 @@ static int bu27008_read_one(struct bu27008_data *data, =
struct iio_dev *idev,
 	if (ret)
 		return ret;
=20
-	ret =3D bu27008_meas_set(data, BU27008_MEAS_EN);
+	ret =3D bu27008_meas_set(data, true);
 	if (ret)
 		return ret;
=20
@@ -574,7 +664,7 @@ static int bu27008_read_one(struct bu27008_data *data, =
struct iio_dev *idev,
 	if (!ret)
 		ret =3D IIO_VAL_INT;
=20
-	if (bu27008_meas_set(data, BU27008_MEAS_DIS))
+	if (bu27008_meas_set(data, false))
 		dev_warn(data->dev, "measurement disabling failed\n");
=20
 	return ret;
@@ -762,10 +852,10 @@ static int bu27008_update_scan_mode(struct iio_dev *i=
dev,
 		chan_sel =3D BU27008_CLEAR2_IR3;
 	}
=20
-	chan_sel =3D FIELD_PREP(BU27008_MASK_CHAN_SEL, chan_sel);
+	chan_sel <<=3D ffs(data->cd->chan_sel_mask) - 1;
=20
-	return regmap_update_bits(data->regmap, BU27008_REG_MODE_CONTROL3,
-				 BU27008_MASK_CHAN_SEL, chan_sel);
+	return regmap_update_bits(data->regmap, data->cd->chan_sel_reg,
+				  data->cd->chan_sel_mask, chan_sel);
 }
=20
 static const struct iio_info bu27008_info =3D {
@@ -794,29 +884,25 @@ static int bu27008_chip_init(struct bu27008_data *dat=
a)
 	 */
 	msleep(1);
=20
-	ret =3D regmap_reinit_cache(data->regmap, &bu27008_regmap);
+	ret =3D regmap_reinit_cache(data->regmap, data->cd->regmap_cfg);
 	if (ret)
 		dev_err(data->dev, "Failed to reinit reg cache\n");
=20
 	return ret;
 }
=20
-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)
+static int bu27008_trigger_set_state(struct iio_trigger *trig, bool state)
 {
 	struct bu27008_data *data =3D iio_trigger_get_drvdata(trig);
 	int ret;
=20
+
 	if (state)
-		ret =3D bu27008_set_drdy_irq(data, BU27008_INT_EN);
+		ret =3D regmap_set_bits(data->regmap, data->cd->drdy_en_reg,
+				      data->cd->drdy_en_mask);
 	else
-		ret =3D bu27008_set_drdy_irq(data, BU27008_INT_DIS);
+		ret =3D regmap_clear_bits(data->regmap, data->cd->drdy_en_reg,
+					data->cd->drdy_en_mask);
 	if (ret)
 		dev_err(data->dev, "Failed to set trigger state\n");
=20
@@ -852,7 +938,7 @@ static irqreturn_t bu27008_trigger_handler(int irq, voi=
d *p)
 	 * After some measurements, it seems reading the
 	 * BU27008_REG_MODE_CONTROL3 debounces the IRQ line
 	 */
-	ret =3D regmap_read(data->regmap, BU27008_REG_MODE_CONTROL3, &dummy);
+	ret =3D regmap_read(data->regmap, data->cd->valid_reg, &dummy);
 	if (ret < 0)
 		goto err_read;
=20
@@ -872,14 +958,14 @@ static int bu27008_buffer_preenable(struct iio_dev *i=
dev)
 {
 	struct bu27008_data *data =3D iio_priv(idev);
=20
-	return bu27008_meas_set(data, BU27008_MEAS_EN);
+	return bu27008_meas_set(data, true);
 }
=20
 static int bu27008_buffer_postdisable(struct iio_dev *idev)
 {
 	struct bu27008_data *data =3D iio_priv(idev);
=20
-	return bu27008_meas_set(data, BU27008_MEAS_DIS);
+	return bu27008_meas_set(data, false);
 }
=20
 static const struct iio_buffer_setup_ops bu27008_buffer_ops =3D {
@@ -952,11 +1038,6 @@ static int bu27008_probe(struct i2c_client *i2c)
 	struct iio_dev *idev;
 	int ret;
=20
-	regmap =3D 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 =3D devm_iio_device_alloc(dev, sizeof(*data));
 	if (!idev)
 		return -ENOMEM;
@@ -967,23 +1048,33 @@ static int bu27008_probe(struct i2c_client *i2c)
=20
 	data =3D iio_priv(idev);
=20
+	data->cd =3D device_get_match_data(&i2c->dev);
+	if (!data->cd)
+		return -ENODEV;
+
+	regmap =3D devm_regmap_init_i2c(i2c, data->cd->regmap_cfg);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap),
+				     "Failed to initialize Regmap\n");
+
+
 	ret =3D regmap_read(regmap, BU27008_REG_SYSTEM_CONTROL, &reg);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to access sensor\n");
=20
 	part_id =3D FIELD_GET(BU27008_MASK_PART_ID, reg);
=20
-	if (part_id !=3D BU27008_ID)
+	if (part_id !=3D data->cd->part_id)
 		dev_warn(dev, "unknown device 0x%x\n", part_id);
=20
-	ret =3D devm_iio_init_iio_gts(dev, BU27008_SCALE_1X, 0, bu27008_gains,
-				    ARRAY_SIZE(bu27008_gains), bu27008_itimes,
+	ret =3D devm_iio_init_iio_gts(dev, data->cd->scale1x, 0, data->cd->gains,
+				    data->cd->num_gains, bu27008_itimes,
 				    ARRAY_SIZE(bu27008_itimes), &data->gts);
 	if (ret)
 		return ret;
=20
-	ret =3D devm_iio_init_iio_gts(dev, BU27008_SCALE_1X, 0, bu27008_gains_ir,
-				    ARRAY_SIZE(bu27008_gains_ir), bu27008_itimes,
+	ret =3D devm_iio_init_iio_gts(dev, data->cd->scale1x, 0, data->cd->gains_=
ir,
+				    data->cd->num_gains_ir, bu27008_itimes,
 				    ARRAY_SIZE(bu27008_itimes), &data->gts_ir);
 	if (ret)
 		return ret;
@@ -993,14 +1084,14 @@ static int bu27008_probe(struct i2c_client *i2c)
 	data->dev =3D dev;
 	data->irq =3D i2c->irq;
=20
-	idev->channels =3D bu27008_channels;
-	idev->num_channels =3D ARRAY_SIZE(bu27008_channels);
-	idev->name =3D "bu27008";
+	idev->channels =3D /* data->cd->cspec; */ &bu27008_channels[0];
+	idev->num_channels =3D /* data->cd->num_channels; */ ARRAY_SIZE(bu27008_c=
hannels);
+	idev->name =3D data->cd->name;
 	idev->info =3D &bu27008_info;
 	idev->modes =3D INDIO_DIRECT_MODE;
 	idev->available_scan_masks =3D bu27008_scan_masks;
=20
-	ret =3D bu27008_chip_init(data);
+	ret =3D data->cd->chip_init(data);
 	if (ret)
 		return ret;
=20
@@ -1021,7 +1112,7 @@ static int bu27008_probe(struct i2c_client *i2c)
 }
=20
 static const struct of_device_id bu27008_of_match[] =3D {
-	{ .compatible =3D "rohm,bu27008" },
+	{ .compatible =3D "rohm,bu27008", .data =3D &bu27008_chip },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, bu27008_of_match);
--=20
2.40.1


--=20
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =3D]=20

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