Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 216 insertions, 58 deletions

diff --git a/drivers/iio/amplifiers/hmc425a.c b/drivers/iio/amplifiers/hmc425a.c
index ed4d729226..2ee4c0d702 100644
--- a/drivers/iio/amplifiers/hmc425a.c
+++ b/drivers/iio/amplifiers/hmc425a.c
@@ -2,9 +2,10 @@
 /*
  * HMC425A and similar Gain Amplifiers
  *
- * Copyright 2020 Analog Devices Inc.
+ * Copyright 2020, 2024 Analog Devices Inc.
  */
 
+#include <linux/bits.h>
 #include <linux/bitops.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -12,6 +13,7 @@
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/kernel.h>
+#include <linux/math.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -20,10 +22,24 @@
 #include <linux/regulator/consumer.h>
 #include <linux/sysfs.h>
 
+/*
+ * The LTC6373 amplifier supports configuring gain using GPIO's with the following
+ *  values (OUTPUT_V / INPUT_V): 0(shutdown), 0.25, 0.5, 1, 2, 4, 8, 16
+ *
+ * Except for the shutdown value, all can be converted to dB using 20 * log10(x)
+ * From here, it is observed that all values are multiples of the '2' gain setting,
+ *  with the correspondent of 6.020dB.
+ */
+#define LTC6373_CONVERSION_CONSTANT	6020
+#define LTC6373_MIN_GAIN_CODE		0x6
+#define LTC6373_CONVERSION_MASK		GENMASK(2, 0)
+#define LTC6373_SHUTDOWN		GENMASK(2, 0)
+
 enum hmc425a_type {
 	ID_HMC425A,
 	ID_HMC540S,
-	ID_ADRF5740
+	ID_ADRF5740,
+	ID_LTC6373,
 };
 
 struct hmc425a_chip_info {
@@ -34,16 +50,110 @@ struct hmc425a_chip_info {
 	int				gain_min;
 	int				gain_max;
 	int				default_gain;
+	int				powerdown_val;
+	bool				has_powerdown;
+
+	int				(*gain_dB_to_code)(int gain, int *code);
+	int				(*code_to_gain_dB)(int code, int *val, int *val2);
 };
 
 struct hmc425a_state {
 	struct	mutex lock; /* protect sensor state */
-	struct	hmc425a_chip_info *chip_info;
+	const struct	hmc425a_chip_info *chip_info;
 	struct	gpio_descs *gpios;
-	enum	hmc425a_type type;
 	u32	gain;
+	bool	powerdown;
 };
 
+static int gain_dB_to_code(struct hmc425a_state *st, int val, int val2, int *code)
+{
+	const struct hmc425a_chip_info *inf = st->chip_info;
+	int gain;
+
+	if (val < 0)
+		gain = (val * 1000) - (val2 / 1000);
+	else
+		gain = (val * 1000) + (val2 / 1000);
+
+	if (gain > inf->gain_max || gain < inf->gain_min)
+		return -EINVAL;
+	if (st->powerdown)
+		return -EPERM;
+
+	return st->chip_info->gain_dB_to_code(gain, code);
+}
+
+static int hmc425a_gain_dB_to_code(int gain, int *code)
+{
+	*code = ~((abs(gain) / 500) & 0x3F);
+	return 0;
+}
+
+static int hmc540s_gain_dB_to_code(int gain, int *code)
+{
+	*code = ~((abs(gain) / 1000) & 0xF);
+	return 0;
+}
+
+static int adrf5740_gain_dB_to_code(int gain, int *code)
+{
+	int temp = (abs(gain) / 2000) & 0xF;
+
+	/* Bit [0-3]: 2dB 4dB 8dB 8dB */
+	*code = temp & BIT(3) ? temp | BIT(2) : temp;
+	return 0;
+}
+
+static int ltc6373_gain_dB_to_code(int gain, int *code)
+{
+	*code = ~(DIV_ROUND_CLOSEST(gain, LTC6373_CONVERSION_CONSTANT) + 3)
+		& LTC6373_CONVERSION_MASK;
+	return 0;
+}
+
+static int code_to_gain_dB(struct hmc425a_state *st, int *val, int *val2)
+{
+	if (st->powerdown)
+		return -EPERM;
+	return st->chip_info->code_to_gain_dB(st->gain, val, val2);
+}
+
+static int hmc425a_code_to_gain_dB(int code, int *val, int *val2)
+{
+	*val = (~code * -500) / 1000;
+	*val2 = ((~code * -500) % 1000) * 1000;
+	return 0;
+}
+
+static int hmc540s_code_to_gain_dB(int code, int *val, int *val2)
+{
+	*val = (~code * -1000) / 1000;
+	*val2 = ((~code * -1000) % 1000) * 1000;
+	return 0;
+}
+
+static int adrf5740_code_to_gain_dB(int code, int *val, int *val2)
+{
+	/*
+	 * Bit [0-3]: 2dB 4dB 8dB 8dB
+	 * When BIT(3) is set, unset BIT(2) and use 3 as double the place value
+	 */
+	code = code & BIT(3) ? code & ~BIT(2) : code;
+	*val = (code * -2000) / 1000;
+	*val2 = ((code * -2000) % 1000) * 1000;
+	return 0;
+}
+
+static int ltc6373_code_to_gain_dB(int code, int *val, int *val2)
+{
+	int gain = ((~code & LTC6373_CONVERSION_MASK) - 3) *
+		   LTC6373_CONVERSION_CONSTANT;
+
+	*val = gain / 1000;
+	*val2 = (gain % 1000) * 1000;
+	return 0;
+}
+
 static int hmc425a_write(struct iio_dev *indio_dev, u32 value)
 {
 	struct hmc425a_state *st = iio_priv(indio_dev);
@@ -61,30 +171,14 @@ static int hmc425a_read_raw(struct iio_dev *indio_dev,
 			    int *val2, long m)
 {
 	struct hmc425a_state *st = iio_priv(indio_dev);
-	int code, gain = 0;
 	int ret;
 
 	mutex_lock(&st->lock);
 	switch (m) {
 	case IIO_CHAN_INFO_HARDWAREGAIN:
-		code = st->gain;
-
-		switch (st->type) {
-		case ID_HMC425A:
-			gain = ~code * -500;
+		ret = code_to_gain_dB(st, val, val2);
+		if (ret)
 			break;
-		case ID_HMC540S:
-			gain = ~code * -1000;
-			break;
-		case ID_ADRF5740:
-			code = code & BIT(3) ? code & ~BIT(2) : code;
-			gain = code * -2000;
-			break;
-		}
-
-		*val = gain / 1000;
-		*val2 = (gain % 1000) * 1000;
-
 		ret = IIO_VAL_INT_PLUS_MICRO_DB;
 		break;
 	default:
@@ -100,34 +194,14 @@ static int hmc425a_write_raw(struct iio_dev *indio_dev,
 			     int val2, long mask)
 {
 	struct hmc425a_state *st = iio_priv(indio_dev);
-	struct hmc425a_chip_info *inf = st->chip_info;
-	int code = 0, gain;
-	int ret;
-
-	if (val < 0)
-		gain = (val * 1000) - (val2 / 1000);
-	else
-		gain = (val * 1000) + (val2 / 1000);
-
-	if (gain > inf->gain_max || gain < inf->gain_min)
-		return -EINVAL;
-
-	switch (st->type) {
-	case ID_HMC425A:
-		code = ~((abs(gain) / 500) & 0x3F);
-		break;
-	case ID_HMC540S:
-		code = ~((abs(gain) / 1000) & 0xF);
-		break;
-	case ID_ADRF5740:
-		code = (abs(gain) / 2000) & 0xF;
-		code = code & BIT(3) ? code | BIT(2) : code;
-		break;
-	}
+	int code = 0, ret;
 
 	mutex_lock(&st->lock);
 	switch (mask) {
 	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = gain_dB_to_code(st, val, val2, &code);
+		if (ret)
+			break;
 		st->gain = code;
 
 		ret = hmc425a_write(indio_dev, st->gain);
@@ -158,6 +232,48 @@ static const struct iio_info hmc425a_info = {
 	.write_raw_get_fmt = &hmc425a_write_raw_get_fmt,
 };
 
+static ssize_t ltc6373_read_powerdown(struct iio_dev *indio_dev,
+				      uintptr_t private,
+				      const struct iio_chan_spec *chan,
+				      char *buf)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+
+	return sysfs_emit(buf, "%d\n", st->powerdown);
+}
+
+static ssize_t ltc6373_write_powerdown(struct iio_dev *indio_dev,
+				       uintptr_t private,
+				       const struct iio_chan_spec *chan,
+				       const char *buf,
+				       size_t len)
+{
+	struct hmc425a_state *st = iio_priv(indio_dev);
+	bool powerdown;
+	int code, ret;
+
+	ret = kstrtobool(buf, &powerdown);
+	if (ret)
+		return ret;
+
+	mutex_lock(&st->lock);
+	st->powerdown = powerdown;
+	code = (powerdown) ? LTC6373_SHUTDOWN : st->gain;
+	hmc425a_write(indio_dev, code);
+	mutex_unlock(&st->lock);
+	return len;
+}
+
+static const struct iio_chan_spec_ext_info ltc6373_ext_info[] = {
+	{
+		.name = "powerdown",
+		.read = ltc6373_read_powerdown,
+		.write = ltc6373_write_powerdown,
+		.shared = IIO_SEPARATE,
+	},
+	{}
+};
+
 #define HMC425A_CHAN(_channel)						\
 {									\
 	.type = IIO_VOLTAGE,						\
@@ -167,20 +283,25 @@ static const struct iio_info hmc425a_info = {
 	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),		\
 }
 
+#define LTC6373_CHAN(_channel)						\
+{									\
+	.type = IIO_VOLTAGE,						\
+	.output = 1,							\
+	.indexed = 1,							\
+	.channel = _channel,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_HARDWAREGAIN),		\
+	.ext_info = ltc6373_ext_info,					\
+}
+
 static const struct iio_chan_spec hmc425a_channels[] = {
 	HMC425A_CHAN(0),
 };
 
-/* Match table for of_platform binding */
-static const struct of_device_id hmc425a_of_match[] = {
-	{ .compatible = "adi,hmc425a", .data = (void *)ID_HMC425A },
-	{ .compatible = "adi,hmc540s", .data = (void *)ID_HMC540S },
-	{ .compatible = "adi,adrf5740", .data = (void *)ID_ADRF5740 },
-	{},
+static const struct iio_chan_spec ltc6373_channels[] = {
+	LTC6373_CHAN(0),
 };
-MODULE_DEVICE_TABLE(of, hmc425a_of_match);
 
-static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
+static const struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
 	[ID_HMC425A] = {
 		.name = "hmc425a",
 		.channels = hmc425a_channels,
@@ -189,6 +310,8 @@ static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
 		.gain_min = -31500,
 		.gain_max = 0,
 		.default_gain = -0x40, /* set default gain -31.5db*/
+		.gain_dB_to_code = hmc425a_gain_dB_to_code,
+		.code_to_gain_dB = hmc425a_code_to_gain_dB,
 	},
 	[ID_HMC540S] = {
 		.name = "hmc540s",
@@ -198,6 +321,8 @@ static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
 		.gain_min = -15000,
 		.gain_max = 0,
 		.default_gain = -0x10, /* set default gain -15.0db*/
+		.gain_dB_to_code = hmc540s_gain_dB_to_code,
+		.code_to_gain_dB = hmc540s_code_to_gain_dB,
 	},
 	[ID_ADRF5740] = {
 		.name = "adrf5740",
@@ -207,6 +332,21 @@ static struct hmc425a_chip_info hmc425a_chip_info_tbl[] = {
 		.gain_min = -22000,
 		.gain_max = 0,
 		.default_gain = 0xF, /* set default gain -22.0db*/
+		.gain_dB_to_code = adrf5740_gain_dB_to_code,
+		.code_to_gain_dB = adrf5740_code_to_gain_dB,
+	},
+	[ID_LTC6373] = {
+		.name = "ltc6373",
+		.channels = ltc6373_channels,
+		.num_channels = ARRAY_SIZE(ltc6373_channels),
+		.num_gpios = 3,
+		.gain_min = -12041, /* gain setting x0.25*/
+		.gain_max = 24082,  /* gain setting x16  */
+		.default_gain = LTC6373_MIN_GAIN_CODE,
+		.powerdown_val = LTC6373_SHUTDOWN,
+		.has_powerdown = true,
+		.gain_dB_to_code = ltc6373_gain_dB_to_code,
+		.code_to_gain_dB = ltc6373_code_to_gain_dB,
 	},
 };
 
@@ -221,9 +361,8 @@ static int hmc425a_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	st = iio_priv(indio_dev);
-	st->type = (uintptr_t)device_get_match_data(&pdev->dev);
 
-	st->chip_info = &hmc425a_chip_info_tbl[st->type];
+	st->chip_info = device_get_match_data(&pdev->dev);
 	indio_dev->num_channels = st->chip_info->num_channels;
 	indio_dev->channels = st->chip_info->channels;
 	indio_dev->name = st->chip_info->name;
@@ -249,12 +388,31 @@ static int hmc425a_probe(struct platform_device *pdev)
 	indio_dev->info = &hmc425a_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
-	/* Set default gain */
-	hmc425a_write(indio_dev, st->gain);
+	if (st->chip_info->has_powerdown) {
+		st->powerdown = true;
+		hmc425a_write(indio_dev, st->chip_info->powerdown_val);
+	} else {
+		/* Set default gain */
+		hmc425a_write(indio_dev, st->gain);
+	}
 
 	return devm_iio_device_register(&pdev->dev, indio_dev);
 }
 
+/* Match table for of_platform binding */
+static const struct of_device_id hmc425a_of_match[] = {
+	{ .compatible = "adi,hmc425a",
+	  .data = &hmc425a_chip_info_tbl[ID_HMC425A]},
+	{ .compatible = "adi,hmc540s",
+	  .data = &hmc425a_chip_info_tbl[ID_HMC540S]},
+	{ .compatible = "adi,adrf5740",
+	  .data = &hmc425a_chip_info_tbl[ID_ADRF5740]},
+	{ .compatible = "adi,ltc6373",
+	  .data = &hmc425a_chip_info_tbl[ID_LTC6373]},
+	{}
+};
+MODULE_DEVICE_TABLE(of, hmc425a_of_match);
+
 static struct platform_driver hmc425a_driver = {
 	.driver = {
 		.name = KBUILD_MODNAME,