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From: Alisa-Dariana Roman <alisadariana@gmail.com>
To: michael.hennerich@analog.com,
	linux-iio@vger.kernel.org,
	devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: alexandru.tachici@analog.com,
	lars@metafoo.de,
	Michael.Hennerich@analog.com,
	jic23@kernel.org,
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	krzysztof.kozlowski+dt@linaro.org,
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	lgirdwood@gmail.com,
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	andy@kernel.org,
	nuno.sa@analog.com,
	marcelo.schmitt@analog.com,
	bigunclemax@gmail.com,
	dlechner@baylibre.com,
	okan.sahin@analog.com,
	fr0st61te@gmail.com,
	alisa.roman@analog.com,
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	schnelle@linux.ibm.com,
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Subject: [PATCH v6 5/5] iio: adc: ad7192: Add AD7194 support
Date: Wed, 17 Apr 2024 20:00:54 +0300
Message-Id: <20240417170054.140587-6-alisa.roman@analog.com>
In-Reply-To: <20240417170054.140587-1-alisa.roman@analog.com>
References: <20240417170054.140587-1-alisa.roman@analog.com>
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Unlike the other AD719Xs, AD7194 has configurable differential
channels. The user can dynamically configure them in the devicetree.

Also modify config AD7192 description for better scaling.

Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
---
 drivers/iio/adc/Kconfig  |  11 +++-
 drivers/iio/adc/ad7192.c | 122 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 126 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 8db68b80b391..74fecc284f1a 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -88,12 +88,17 @@ config AD7173
 	  called ad7173.
 
 config AD7192
-	tristate "Analog Devices AD7190 AD7192 AD7193 AD7195 ADC driver"
+	tristate "Analog Devices AD7192 and similar ADC driver"
 	depends on SPI
 	select AD_SIGMA_DELTA
 	help
-	  Say yes here to build support for Analog Devices AD7190,
-	  AD7192, AD7193 or AD7195 SPI analog to digital converters (ADC).
+	  Say yes here to build support for Analog Devices SPI analog to digital
+	  converters (ADC):
+	  - AD7190
+	  - AD7192
+	  - AD7193
+	  - AD7194
+	  - AD7195
 	  If unsure, say N (but it's safe to say "Y").
 
 	  To compile this driver as a module, choose M here: the
diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index 8d56cf889973..dc113405f1bc 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * AD7190 AD7192 AD7193 AD7195 SPI ADC driver
+ * AD7192 and similar SPI ADC driver
  *
  * Copyright 2011-2015 Analog Devices Inc.
  */
@@ -128,10 +128,21 @@
 #define AD7193_CH_AIN8		0x480 /* AIN7 - AINCOM */
 #define AD7193_CH_AINCOM	0x600 /* AINCOM - AINCOM */
 
+#define AD7194_CH_POS(x)	(((x) - 1) << 4)
+#define AD7194_CH_NEG(x)	((x) - 1)
+#define AD7194_CH_DIFF(pos, neg) \
+		(((neg) == 0 ? BIT(10) : AD7194_CH_NEG(neg)) | AD7194_CH_POS(pos))
+#define AD7194_CH_TEMP		0x100 /* Temp sensor */
+#define AD7194_CH_BASE_NR	18
+#define AD7194_CH_AIN_START	1
+#define AD7194_CH_AIN_NR	16
+#define AD7194_CH_DIFF_NR_MAX	256
+
 /* ID Register Bit Designations (AD7192_REG_ID) */
 #define CHIPID_AD7190		0x4
 #define CHIPID_AD7192		0x0
 #define CHIPID_AD7193		0x2
+#define CHIPID_AD7194		0x3
 #define CHIPID_AD7195		0x6
 #define AD7192_ID_MASK		GENMASK(3, 0)
 
@@ -169,6 +180,7 @@ enum {
 	ID_AD7190,
 	ID_AD7192,
 	ID_AD7193,
+	ID_AD7194,
 	ID_AD7195,
 };
 
@@ -178,6 +190,7 @@ struct ad7192_chip_info {
 	const struct iio_chan_spec	*channels;
 	u8				num_channels;
 	const struct iio_info		*info;
+	int (*parse_channels)(struct iio_dev *indio_dev);
 };
 
 struct ad7192_state {
@@ -931,6 +944,15 @@ static const struct iio_info ad7192_info = {
 	.update_scan_mode = ad7192_update_scan_mode,
 };
 
+static const struct iio_info ad7194_info = {
+	.read_raw = ad7192_read_raw,
+	.write_raw = ad7192_write_raw,
+	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
+	.read_avail = ad7192_read_avail,
+	.validate_trigger = ad_sd_validate_trigger,
+	.update_scan_mode = ad7192_update_scan_mode,
+};
+
 static const struct iio_info ad7195_info = {
 	.read_raw = ad7192_read_raw,
 	.write_raw = ad7192_write_raw,
@@ -1022,6 +1044,84 @@ static const struct iio_chan_spec ad7193_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(14),
 };
 
+static int ad7194_parse_channel(struct fwnode_handle *child,
+				struct iio_chan_spec *ad7194_channel)
+{
+	u32 ain[2];
+	int ret;
+
+	ret = fwnode_property_read_u32_array(child, "diff-channels", ain,
+					     ARRAY_SIZE(ain));
+	if (ret)
+		return ret;
+
+	if (!in_range(ain[0], AD7194_CH_AIN_START, AD7194_CH_AIN_NR) ||
+	    !in_range(ain[1], AD7194_CH_AIN_START, AD7194_CH_AIN_NR))
+		return -EINVAL;
+
+	ad7194_channel->channel = ain[0];
+	ad7194_channel->channel2 = ain[1];
+	ad7194_channel->address = AD7194_CH_DIFF(ain[0], ain[1]);
+
+	return 0;
+}
+
+static int ad7194_parse_channels(struct iio_dev *indio_dev)
+{
+	struct device *dev = indio_dev->dev.parent;
+	struct iio_chan_spec *ad7194_channels;
+	struct fwnode_handle *child;
+	struct iio_chan_spec ad7194_chan = AD7193_CHANNEL(0, 0, 0);
+	struct iio_chan_spec ad7194_chan_diff = AD7193_DIFF_CHANNEL(0, 0, 0, 0);
+	struct iio_chan_spec ad7194_chan_temp = AD719x_TEMP_CHANNEL(0, 0);
+	struct iio_chan_spec ad7194_chan_timestamp = IIO_CHAN_SOFT_TIMESTAMP(0);
+	unsigned int num_channels, index = 0, ain_chan;
+	int ret;
+
+	num_channels = device_get_child_node_count(dev);
+	if (num_channels > AD7194_CH_DIFF_NR_MAX)
+		return -EINVAL;
+
+	num_channels += AD7194_CH_BASE_NR;
+
+	ad7194_channels = devm_kcalloc(dev, num_channels,
+				       sizeof(*ad7194_channels), GFP_KERNEL);
+	if (!ad7194_channels)
+		return -ENOMEM;
+
+	indio_dev->channels = ad7194_channels;
+	indio_dev->num_channels = num_channels;
+
+	device_for_each_child_node(dev, child) {
+		*ad7194_channels = ad7194_chan_diff;
+		ad7194_channels->scan_index = index++;
+		ret = ad7194_parse_channel(child, ad7194_channels);
+		if (ret) {
+			fwnode_handle_put(child);
+			return ret;
+		}
+		ad7194_channels++;
+	}
+
+	*ad7194_channels = ad7194_chan_temp;
+	ad7194_channels->scan_index = index++;
+	ad7194_channels->address = AD7194_CH_TEMP;
+	ad7194_channels++;
+
+	for (ain_chan = 1; ain_chan <= 16; ain_chan++) {
+		*ad7194_channels = ad7194_chan;
+		ad7194_channels->scan_index = index++;
+		ad7194_channels->channel = ain_chan;
+		ad7194_channels->address = AD7194_CH_DIFF(ain_chan, 0);
+		ad7194_channels++;
+	}
+
+	*ad7194_channels = ad7194_chan_timestamp;
+	ad7194_channels->scan_index = index;
+
+	return 0;
+}
+
 static const struct ad7192_chip_info ad7192_chip_info_tbl[] = {
 	[ID_AD7190] = {
 		.chip_id = CHIPID_AD7190,
@@ -1044,6 +1144,12 @@ static const struct ad7192_chip_info ad7192_chip_info_tbl[] = {
 		.num_channels = ARRAY_SIZE(ad7193_channels),
 		.info = &ad7192_info,
 	},
+	[ID_AD7194] = {
+		.chip_id = CHIPID_AD7194,
+		.name = "ad7194",
+		.info = &ad7194_info,
+		.parse_channels = ad7194_parse_channels,
+	},
 	[ID_AD7195] = {
 		.chip_id = CHIPID_AD7195,
 		.name = "ad7195",
@@ -1148,9 +1254,15 @@ static int ad7192_probe(struct spi_device *spi)
 
 	indio_dev->name = st->chip_info->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels = st->chip_info->channels;
-	indio_dev->num_channels = st->chip_info->num_channels;
 	indio_dev->info = st->chip_info->info;
+	if (st->chip_info->parse_channels) {
+		ret = st->chip_info->parse_channels(indio_dev);
+		if (ret)
+			return ret;
+	} else {
+		indio_dev->channels = st->chip_info->channels;
+		indio_dev->num_channels = st->chip_info->num_channels;
+	}
 
 	ret = ad_sd_init(&st->sd, indio_dev, spi, &ad7192_sigma_delta_info);
 	if (ret)
@@ -1189,6 +1301,7 @@ static const struct of_device_id ad7192_of_match[] = {
 	{ .compatible = "adi,ad7190", .data = &ad7192_chip_info_tbl[ID_AD7190] },
 	{ .compatible = "adi,ad7192", .data = &ad7192_chip_info_tbl[ID_AD7192] },
 	{ .compatible = "adi,ad7193", .data = &ad7192_chip_info_tbl[ID_AD7193] },
+	{ .compatible = "adi,ad7194", .data = &ad7192_chip_info_tbl[ID_AD7194] },
 	{ .compatible = "adi,ad7195", .data = &ad7192_chip_info_tbl[ID_AD7195] },
 	{}
 };
@@ -1198,6 +1311,7 @@ static const struct spi_device_id ad7192_ids[] = {
 	{ "ad7190", (kernel_ulong_t)&ad7192_chip_info_tbl[ID_AD7190] },
 	{ "ad7192", (kernel_ulong_t)&ad7192_chip_info_tbl[ID_AD7192] },
 	{ "ad7193", (kernel_ulong_t)&ad7192_chip_info_tbl[ID_AD7193] },
+	{ "ad7194", (kernel_ulong_t)&ad7192_chip_info_tbl[ID_AD7194] },
 	{ "ad7195", (kernel_ulong_t)&ad7192_chip_info_tbl[ID_AD7195] },
 	{}
 };
@@ -1214,6 +1328,6 @@ static struct spi_driver ad7192_driver = {
 module_spi_driver(ad7192_driver);
 
 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
-MODULE_DESCRIPTION("Analog Devices AD7190, AD7192, AD7193, AD7195 ADC");
+MODULE_DESCRIPTION("Analog Devices AD7192 and similar ADC");
 MODULE_LICENSE("GPL v2");
 MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA);
-- 
2.34.1