Improve MCP3911 driver

index 1cb4590fe412..f581cefb6719 100644
@@ -113,6 +113,8 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
 		if (ret)
 			goto out;
 
+		*val = sign_extend32(*val, 23);
+
 		ret = IIO_VAL_INT;
 		break;
 

index f581cefb6719..f8875076ae80 100644
@@ -210,7 +210,14 @@ static int mcp3911_config(struct mcp3911 *adc)
 	u32 configreg;
 	int ret;
 
-	device_property_read_u32(dev, "device-addr", &adc->dev_addr);
+	ret = device_property_read_u32(dev, "microchip,device-addr", &adc->dev_addr);
+
+	/*
+	 * Fallback to "device-addr" due to historical mismatch between
+	 * dt-bindings and implementation
+	 */
+	if (ret)
+		device_property_read_u32(dev, "device-addr", &adc->dev_addr);
 	if (adc->dev_addr > 3) {
 		dev_err(&adc->spi->dev,
 			"invalid device address (%i). Must be in range 0-3.\n",

index f8875076ae80..890af7dca62d 100644
@@ -40,8 +40,8 @@
 #define MCP3911_CHANNEL(x)		(MCP3911_REG_CHANNEL0 + x * 3)
 #define MCP3911_OFFCAL(x)		(MCP3911_REG_OFFCAL_CH0 + x * 6)
 
-/* Internal voltage reference in uV */
-#define MCP3911_INT_VREF_UV		1200000
+/* Internal voltage reference in mV */
+#define MCP3911_INT_VREF_MV		1200
 
 #define MCP3911_REG_READ(reg, id)	((((reg) << 1) | ((id) << 5) | (1 << 0)) & 0xff)
 #define MCP3911_REG_WRITE(reg, id)	((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff)

@@ -139,11 +139,18 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
 
 			*val = ret / 1000;
 		} else {
-			*val = MCP3911_INT_VREF_UV;
+			*val = MCP3911_INT_VREF_MV;
 		}
 
-		*val2 = 24;
-		ret = IIO_VAL_FRACTIONAL_LOG2;
+		/*
+		 * For 24bit Conversion
+		 * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
+		 * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
+		 */
+
+		/* val2 = (2^23 * 1.5) */
+		*val2 = 12582912;
+		ret = IIO_VAL_FRACTIONAL;
 		break;
 	}
 

index 890af7dca62d..7e2efe702e57 100644
@@ -258,6 +258,13 @@ static int mcp3911_config(struct mcp3911 *adc)
 	return  mcp3911_write(adc, MCP3911_REG_CONFIG, configreg, 2);
 }
 
+static void mcp3911_cleanup_regulator(void *_adc)
+{
+	struct mcp3911 *adc = _adc;
+
+	regulator_disable(adc->vref);
+}
+
 static int mcp3911_probe(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev;

@@ -286,9 +293,14 @@ static int mcp3911_probe(struct spi_device *spi)
 		ret = regulator_enable(adc->vref);
 		if (ret)
 			return ret;
+
+		ret = devm_add_action_or_reset(&spi->dev,
+				mcp3911_cleanup_regulator, adc);
+		if (ret)
+			return ret;
 	}
 
-	adc->clki = devm_clk_get(&adc->spi->dev, NULL);
+	adc->clki = devm_clk_get_enabled(&adc->spi->dev, NULL);
 	if (IS_ERR(adc->clki)) {
 		if (PTR_ERR(adc->clki) == -ENOENT) {
 			adc->clki = NULL;

@@ -296,21 +308,13 @@ static int mcp3911_probe(struct spi_device *spi)
 			dev_err(&adc->spi->dev,
 				"failed to get adc clk (%ld)\n",
 				PTR_ERR(adc->clki));
-			ret = PTR_ERR(adc->clki);
-			goto reg_disable;
-		}
-	} else {
-		ret = clk_prepare_enable(adc->clki);
-		if (ret < 0) {
-			dev_err(&adc->spi->dev,
-				"Failed to enable clki: %d\n", ret);
-			goto reg_disable;
+			return PTR_ERR(adc->clki);
 		}
 	}
 
 	ret = mcp3911_config(adc);
 	if (ret)
-		goto clk_disable;
+		return ret;
 
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;

@@ -322,31 +326,7 @@ static int mcp3911_probe(struct spi_device *spi)
 
 	mutex_init(&adc->lock);
 
-	ret = iio_device_register(indio_dev);
-	if (ret)
-		goto clk_disable;
-
-	return ret;
-
-clk_disable:
-	clk_disable_unprepare(adc->clki);
-reg_disable:
-	if (adc->vref)
-		regulator_disable(adc->vref);
-
-	return ret;
-}
-
-static void mcp3911_remove(struct spi_device *spi)
-{
-	struct iio_dev *indio_dev = spi_get_drvdata(spi);
-	struct mcp3911 *adc = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-
-	clk_disable_unprepare(adc->clki);
-	if (adc->vref)
-		regulator_disable(adc->vref);
+	return devm_iio_device_register(&adc->spi->dev, indio_dev);
 }
 
 static const struct of_device_id mcp3911_dt_ids[] = {

@@ -367,7 +347,6 @@ static struct spi_driver mcp3911_driver = {
 		.of_match_table = mcp3911_dt_ids,
 	},
 	.probe = mcp3911_probe,
-	.remove = mcp3911_remove,
 	.id_table = mcp3911_id,
 };
 module_spi_driver(mcp3911_driver);

181 lines not on this page · raw message

index 4452b01c76f3..b76d825c984d 100644
@@ -31,6 +31,7 @@
 #define MCP3911_REG_GAIN		0x09
 
 #define MCP3911_REG_STATUSCOM		0x0a
+#define MCP3911_STATUSCOM_DRHIZ         BIT(12)
 #define MCP3911_STATUSCOM_READ		GENMASK(7, 6)
 #define MCP3911_STATUSCOM_CH1_24WIDTH	BIT(4)
 #define MCP3911_STATUSCOM_CH0_24WIDTH	BIT(3)

@@ -64,6 +65,7 @@ struct mcp3911 {
 	struct regulator *vref;
 	struct clk *clki;
 	u32 dev_addr;
+	struct iio_trigger *trig;
 	struct {
 		u32 channels[MCP3911_NUM_CHANNELS];
 		s64 ts __aligned(8);

@@ -346,6 +348,23 @@ static void mcp3911_cleanup_regulator(void *_adc)
 	regulator_disable(adc->vref);
 }
 
+static int mcp3911_set_trigger_state(struct iio_trigger *trig, bool enable)
+{
+	struct mcp3911 *adc = iio_trigger_get_drvdata(trig);
+
+	if (enable)
+		enable_irq(adc->spi->irq);
+	else
+		disable_irq(adc->spi->irq);
+
+	return 0;
+}
+
+static const struct iio_trigger_ops mcp3911_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+	.set_trigger_state = mcp3911_set_trigger_state,
+};
+
 static int mcp3911_probe(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev;

@@ -397,6 +416,15 @@ static int mcp3911_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
+	if (device_property_read_bool(&adc->spi->dev, "microchip,data-ready-hiz"))
+		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
+				0, 2);
+	else
+		ret = mcp3911_update(adc, MCP3911_REG_STATUSCOM, MCP3911_STATUSCOM_DRHIZ,
+				MCP3911_STATUSCOM_DRHIZ, 2);
+	if (ret)
+		return ret;
+
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &mcp3911_info;

@@ -407,6 +435,31 @@ static int mcp3911_probe(struct spi_device *spi)
 
 	mutex_init(&adc->lock);
 
+	if (spi->irq > 0) {
+		adc->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
+				indio_dev->name,
+				iio_device_id(indio_dev));
+		if (!adc->trig)
+			return PTR_ERR(adc->trig);
+
+		adc->trig->ops = &mcp3911_trigger_ops;
+		iio_trigger_set_drvdata(adc->trig, adc);
+		ret = devm_iio_trigger_register(&spi->dev, adc->trig);
+		if (ret)
+			return ret;
+
+		/*
+		 * The device generates interrupts as long as it is powered up.
+		 * Some platforms might not allow the option to power it down so
+		 * don't enable the interrupt to avoid extra load on the system.
+		 */
+		ret = devm_request_irq(&spi->dev, spi->irq,
+				&iio_trigger_generic_data_rdy_poll, IRQF_NO_AUTOEN | IRQF_ONESHOT,
+				indio_dev->name, adc->trig);
+		if (ret)
+			return ret;
+	}
+
 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
 			NULL,
 			mcp3911_trigger_handler, NULL);

index b76d825c984d..0151258b456c 100644
@@ -41,6 +41,7 @@
 #define MCP3911_REG_CONFIG		0x0c
 #define MCP3911_CONFIG_CLKEXT		BIT(1)
 #define MCP3911_CONFIG_VREFEXT		BIT(2)
+#define MCP3911_CONFIG_OSR		GENMASK(13, 11)
 
 #define MCP3911_REG_OFFCAL_CH0		0x0e
 #define MCP3911_REG_GAINCAL_CH0		0x11

@@ -59,6 +60,8 @@
 
 #define MCP3911_NUM_CHANNELS		2
 
+static const int mcp3911_osr_table[] = { 32, 64, 128, 256, 512, 1024, 2048, 4096 };
+
 struct mcp3911 {
 	struct spi_device *spi;
 	struct mutex lock;

@@ -117,6 +120,36 @@ static int mcp3911_update(struct mcp3911 *adc, u8 reg, u32 mask,
 	return mcp3911_write(adc, reg, val, len);
 }
 
+static int mcp3911_write_raw_get_fmt(struct iio_dev *indio_dev,
+					struct iio_chan_spec const *chan,
+					long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		return IIO_VAL_INT_PLUS_NANO;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		return IIO_VAL_INT;
+	default:
+		return IIO_VAL_INT_PLUS_NANO;
+	}
+}
+
+static int mcp3911_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type, int *length,
+			     long info)
+{
+	switch (info) {
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		*type = IIO_VAL_INT;
+		*vals = mcp3911_osr_table;
+		*length = ARRAY_SIZE(mcp3911_osr_table);
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
 static int mcp3911_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *channel, int *val,
 			    int *val2, long mask)

@@ -145,6 +178,15 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
 
 		ret = IIO_VAL_INT;
 		break;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		ret = mcp3911_read(adc, MCP3911_REG_CONFIG, val, 2);
+		if (ret)
+			goto out;
+
+		*val = FIELD_GET(MCP3911_CONFIG_OSR, *val);
+		*val = 32 << *val;
+		ret = IIO_VAL_INT;
+		break;
 
 	case IIO_CHAN_INFO_SCALE:
 		if (adc->vref) {

@@ -204,6 +246,17 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 				MCP3911_STATUSCOM_EN_OFFCAL,
 				MCP3911_STATUSCOM_EN_OFFCAL, 2);
 		break;
+
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		for (int i = 0; i < sizeof(mcp3911_osr_table); i++) {
+			if (val == mcp3911_osr_table[i]) {
+				val = FIELD_PREP(MCP3911_CONFIG_OSR, i);
+				ret = mcp3911_update(adc, MCP3911_REG_CONFIG, MCP3911_CONFIG_OSR,
+						val, 2);
+				break;
+			}
+		}
+		break;
 	}
 
 out:

@@ -216,9 +269,12 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 		.indexed = 1,					\
 		.channel = idx,					\
 		.scan_index = idx,				\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
 			BIT(IIO_CHAN_INFO_OFFSET) |		\
 			BIT(IIO_CHAN_INFO_SCALE),		\
+		.info_mask_shared_by_type_available =		\
+			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
 		.scan_type = {					\
 			.sign = 's',				\
 			.realbits = 24,				\

@@ -278,6 +334,8 @@ static irqreturn_t mcp3911_trigger_handler(int irq, void *p)
 static const struct iio_info mcp3911_info = {
 	.read_raw = mcp3911_read_raw,
 	.write_raw = mcp3911_write_raw,
+	.read_avail = mcp3911_read_avail,
+	.write_raw_get_fmt = mcp3911_write_raw_get_fmt,
 };
 
 static int mcp3911_config(struct mcp3911 *adc)

index 0151258b456c..de85a87b9287 100644
@@ -29,6 +29,8 @@
 #define MCP3911_REG_MOD			0x06
 #define MCP3911_REG_PHASE		0x07
 #define MCP3911_REG_GAIN		0x09
+#define MCP3911_GAIN_MASK(ch)		(GENMASK(2, 0) << 3 * ch)
+#define MCP3911_GAIN_VAL(ch, val)      ((val << 3 * ch) & MCP3911_GAIN_MASK(ch))
 
 #define MCP3911_REG_STATUSCOM		0x0a
 #define MCP3911_STATUSCOM_DRHIZ         BIT(12)

@@ -59,8 +61,10 @@
 #define MCP3911_REG_WRITE(reg, id)	((((reg) << 1) | ((id) << 5) | (0 << 0)) & 0xff)
 
 #define MCP3911_NUM_CHANNELS		2
+#define MCP3911_NUM_SCALES		6
 
 static const int mcp3911_osr_table[] = { 32, 64, 128, 256, 512, 1024, 2048, 4096 };
+static u32 mcp3911_scale_table[MCP3911_NUM_SCALES][2];
 
 struct mcp3911 {
 	struct spi_device *spi;

@@ -69,6 +73,7 @@ struct mcp3911 {
 	struct clk *clki;
 	u32 dev_addr;
 	struct iio_trigger *trig;
+	u32 gain[MCP3911_NUM_CHANNELS];
 	struct {
 		u32 channels[MCP3911_NUM_CHANNELS];
 		s64 ts __aligned(8);

@@ -145,6 +150,11 @@ static int mcp3911_read_avail(struct iio_dev *indio_dev,
 		*vals = mcp3911_osr_table;
 		*length = ARRAY_SIZE(mcp3911_osr_table);
 		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SCALE:
+		*type = IIO_VAL_INT_PLUS_NANO;
+		*vals = (int *)mcp3911_scale_table;
+		*length = ARRAY_SIZE(mcp3911_scale_table) * 2;
+		return IIO_AVAIL_LIST;
 	default:
 		return -EINVAL;
 	}

@@ -189,29 +199,9 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
 		break;
 
 	case IIO_CHAN_INFO_SCALE:
-		if (adc->vref) {
-			ret = regulator_get_voltage(adc->vref);
-			if (ret < 0) {
-				dev_err(indio_dev->dev.parent,
-					"failed to get vref voltage: %d\n",
-				       ret);
-				goto out;
-			}
-
-			*val = ret / 1000;
-		} else {
-			*val = MCP3911_INT_VREF_MV;
-		}
-
-		/*
-		 * For 24bit Conversion
-		 * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
-		 * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
-		 */
-
-		/* val2 = (2^23 * 1.5) */
-		*val2 = 12582912;
-		ret = IIO_VAL_FRACTIONAL;
+		*val = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][0];
+		*val2 = mcp3911_scale_table[ilog2(adc->gain[channel->channel])][1];
+		ret = IIO_VAL_INT_PLUS_NANO;
 		break;
 	}
 

@@ -229,6 +219,18 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 
 	mutex_lock(&adc->lock);
 	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
+			if (val == mcp3911_scale_table[i][0] &&
+				val2 == mcp3911_scale_table[i][1]) {
+
+				adc->gain[channel->channel] = BIT(i);
+				ret = mcp3911_update(adc, MCP3911_REG_GAIN,
+						MCP3911_GAIN_MASK(channel->channel),
+						MCP3911_GAIN_VAL(channel->channel, i), 1);
+			}
+		}
+		break;
 	case IIO_CHAN_INFO_OFFSET:
 		if (val2 != 0) {
 			ret = -EINVAL;

@@ -264,6 +266,47 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 	return ret;
 }
 
+static int mcp3911_calc_scale_table(struct mcp3911 *adc)
+{
+	u32 ref = MCP3911_INT_VREF_MV;
+	u32 div;
+	int ret;
+	int tmp0, tmp1;
+	s64 tmp2;
+
+	if (adc->vref) {
+		ret = regulator_get_voltage(adc->vref);
+		if (ret < 0) {
+			dev_err(&adc->spi->dev,
+				"failed to get vref voltage: %d\n",
+			       ret);
+			return ret;
+		}
+
+		ref = ret / 1000;
+	}
+
+	/*
+	 * For 24-bit Conversion
+	 * Raw = ((Voltage)/(Vref) * 2^23 * Gain * 1.5
+	 * Voltage = Raw * (Vref)/(2^23 * Gain * 1.5)
+	 *
+	 * ref = Reference voltage
+	 * div = (2^23 * 1.5 * gain) = 12582912 * gain
+	 */
+	for (int i = 0; i < MCP3911_NUM_SCALES; i++) {
+		div = 12582912 * BIT(i);
+		tmp2 = div_s64((s64)ref * 1000000000LL, div);
+		tmp1 = div;
+		tmp0 = (int)div_s64_rem(tmp2, 1000000000, &tmp1);
+
+		mcp3911_scale_table[i][0] = 0;
+		mcp3911_scale_table[i][1] = tmp1;
+	}
+
+	return 0;
+}
+
 #define MCP3911_CHAN(idx) {					\
 		.type = IIO_VOLTAGE,				\
 		.indexed = 1,					\

@@ -273,8 +316,10 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
 			BIT(IIO_CHAN_INFO_OFFSET) |		\
 			BIT(IIO_CHAN_INFO_SCALE),		\
-		.info_mask_shared_by_type_available =		\
+		.info_mask_shared_by_type_available =           \
 			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
+		.info_mask_separate_available =			\
+			BIT(IIO_CHAN_INFO_SCALE),		\
 		.scan_type = {					\
 			.sign = 's',				\
 			.realbits = 24,				\

@@ -483,6 +528,20 @@ static int mcp3911_probe(struct spi_device *spi)
 	if (ret)
 		return ret;
 
+	ret = mcp3911_calc_scale_table(adc);
+	if (ret)
+		return ret;
+
+       /* Set gain to 1 for all channels */
+	for (int i = 0; i < MCP3911_NUM_CHANNELS; i++) {
+		adc->gain[i] = 1;
+		ret = mcp3911_update(adc, MCP3911_REG_GAIN,
+				MCP3911_GAIN_MASK(i),
+				MCP3911_GAIN_VAL(i, 0), 1);
+		if (ret)
+			return ret;
+	}
+
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &mcp3911_info;