15 files changed, 398 insertions, 37 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 9554890a3200..5d8540b7b427 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -55,6 +55,16 @@ config AD7291
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7291.
 
+config AD7292
+	tristate "Analog Devices AD7292 ADC driver"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices AD7292
+	  8 Channel ADC with temperature sensor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7292.
+
 config AD7298
 	tristate "Analog Devices AD7298 ADC driver"
 	depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 5ecc481c2967..a1f1fbec0f87 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
 obj-$(CONFIG_AD7124) += ad7124.o
 obj-$(CONFIG_AD7266) += ad7266.o
 obj-$(CONFIG_AD7291) += ad7291.o
+obj-$(CONFIG_AD7292) += ad7292.o
 obj-$(CONFIG_AD7298) += ad7298.o
 obj-$(CONFIG_AD7923) += ad7923.o
 obj-$(CONFIG_AD7476) += ad7476.o
diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c
new file mode 100644
index 000000000000..a6798f7dfdb8
--- /dev/null
+++ b/drivers/iio/adc/ad7292.c
@@ -0,0 +1,350 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Analog Devices AD7292 SPI ADC driver
+ *
+ * Copyright 2019 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/iio.h>
+
+#define ADI_VENDOR_ID 0x0018
+
+/* AD7292 registers definition */
+#define AD7292_REG_VENDOR_ID		0x00
+#define AD7292_REG_CONF_BANK		0x05
+#define AD7292_REG_CONV_COMM		0x0E
+#define AD7292_REG_ADC_CH(x)		(0x10 + (x))
+
+/* AD7292 configuration bank subregisters definition */
+#define AD7292_BANK_REG_VIN_RNG0	0x10
+#define AD7292_BANK_REG_VIN_RNG1	0x11
+#define AD7292_BANK_REG_SAMP_MODE	0x12
+
+#define AD7292_RD_FLAG_MSK(x)		(BIT(7) | ((x) & 0x3F))
+
+/* AD7292_REG_ADC_CONVERSION */
+#define AD7292_ADC_DATA_MASK		GENMASK(15, 6)
+#define AD7292_ADC_DATA(x)		FIELD_GET(AD7292_ADC_DATA_MASK, x)
+
+/* AD7292_CHANNEL_SAMPLING_MODE */
+#define AD7292_CH_SAMP_MODE(reg, ch)	(((reg) >> 8) & BIT(ch))
+
+/* AD7292_CHANNEL_VIN_RANGE */
+#define AD7292_CH_VIN_RANGE(reg, ch)	((reg) & BIT(ch))
+
+#define AD7292_VOLTAGE_CHAN(_chan)					\
+{									\
+	.type = IIO_VOLTAGE,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
+			      BIT(IIO_CHAN_INFO_SCALE),			\
+	.indexed = 1,							\
+	.channel = _chan,						\
+}
+
+static const struct iio_chan_spec ad7292_channels[] = {
+	AD7292_VOLTAGE_CHAN(0),
+	AD7292_VOLTAGE_CHAN(1),
+	AD7292_VOLTAGE_CHAN(2),
+	AD7292_VOLTAGE_CHAN(3),
+	AD7292_VOLTAGE_CHAN(4),
+	AD7292_VOLTAGE_CHAN(5),
+	AD7292_VOLTAGE_CHAN(6),
+	AD7292_VOLTAGE_CHAN(7)
+};
+
+static const struct iio_chan_spec ad7292_channels_diff[] = {
+	{
+		.type = IIO_VOLTAGE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.indexed = 1,
+		.differential = 1,
+		.channel = 0,
+		.channel2 = 1,
+	},
+	AD7292_VOLTAGE_CHAN(2),
+	AD7292_VOLTAGE_CHAN(3),
+	AD7292_VOLTAGE_CHAN(4),
+	AD7292_VOLTAGE_CHAN(5),
+	AD7292_VOLTAGE_CHAN(6),
+	AD7292_VOLTAGE_CHAN(7)
+};
+
+struct ad7292_state {
+	struct spi_device *spi;
+	struct regulator *reg;
+	unsigned short vref_mv;
+
+	__be16 d16 ____cacheline_aligned;
+	u8 d8[2];
+};
+
+static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)
+{
+	int ret;
+
+	st->d8[0] = AD7292_RD_FLAG_MSK(addr);
+
+	ret = spi_write_then_read(st->spi, st->d8, 1, &st->d16, 2);
+	if (ret < 0)
+		return ret;
+
+	return be16_to_cpu(st->d16);
+}
+
+static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int addr,
+				  unsigned int sub_addr, unsigned int len)
+{
+	unsigned int shift = 16 - (8 * len);
+	int ret;
+
+	st->d8[0] = AD7292_RD_FLAG_MSK(addr);
+	st->d8[1] = sub_addr;
+
+	ret = spi_write_then_read(st->spi, st->d8, 2, &st->d16, len);
+	if (ret < 0)
+		return ret;
+
+	return (be16_to_cpu(st->d16) >> shift);
+}
+
+static int ad7292_single_conversion(struct ad7292_state *st,
+				    unsigned int chan_addr)
+{
+	int ret;
+
+	struct spi_transfer t[] = {
+		{
+			.tx_buf = &st->d8,
+			.len = 4,
+			.delay_usecs = 6,
+		}, {
+			.rx_buf = &st->d16,
+			.len = 2,
+		},
+	};
+
+	st->d8[0] = chan_addr;
+	st->d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM);
+
+	ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
+
+	if (ret < 0)
+		return ret;
+
+	return be16_to_cpu(st->d16);
+}
+
+static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)
+{
+	int samp_mode, range0, range1, factor = 1;
+
+	/*
+	 * Every AD7292 ADC channel may have its input range adjusted according
+	 * to the settings at the ADC sampling mode and VIN range subregisters.
+	 * For a given channel, the minimum input range is equal to Vref, and it
+	 * may be increased by a multiplier factor of 2 or 4 according to the
+	 * following rule:
+	 * If channel is being sampled with respect to AGND:
+	 *	factor = 4 if VIN range0 and VIN range1 equal 0
+	 *	factor = 2 if only one of VIN ranges equal 1
+	 *	factor = 1 if both VIN range0 and VIN range1 equal 1
+	 * If channel is being sampled with respect to AVDD:
+	 *	factor = 4 if VIN range0 and VIN range1 equal 0
+	 *	Behavior is undefined if any of VIN range doesn't equal 0
+	 */
+
+	samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
+					   AD7292_BANK_REG_SAMP_MODE, 2);
+
+	if (samp_mode < 0)
+		return samp_mode;
+
+	range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
+					AD7292_BANK_REG_VIN_RNG0, 2);
+
+	if (range0 < 0)
+		return range0;
+
+	range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
+					AD7292_BANK_REG_VIN_RNG1, 2);
+
+	if (range1 < 0)
+		return range1;
+
+	if (AD7292_CH_SAMP_MODE(samp_mode, channel)) {
+		/* Sampling with respect to AGND */
+		if (!AD7292_CH_VIN_RANGE(range0, channel))
+			factor *= 2;
+
+		if (!AD7292_CH_VIN_RANGE(range1, channel))
+			factor *= 2;
+
+	} else {
+		/* Sampling with respect to AVDD */
+		if (AD7292_CH_VIN_RANGE(range0, channel) ||
+		    AD7292_CH_VIN_RANGE(range1, channel))
+			return -EPERM;
+
+		factor = 4;
+	}
+
+	return factor;
+}
+
+static int ad7292_read_raw(struct iio_dev *indio_dev,
+			   const struct iio_chan_spec *chan,
+			   int *val, int *val2, long info)
+{
+	struct ad7292_state *st = iio_priv(indio_dev);
+	unsigned int ch_addr;
+	int ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		ch_addr = AD7292_REG_ADC_CH(chan->channel);
+		ret = ad7292_single_conversion(st, ch_addr);
+		if (ret < 0)
+			return ret;
+
+		*val = AD7292_ADC_DATA(ret);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/*
+		 * To convert a raw value to standard units, the IIO defines
+		 * this formula: Scaled value = (raw + offset) * scale.
+		 * For the scale to be a correct multiplier for (raw + offset),
+		 * it must be calculated as the input range divided by the
+		 * number of possible distinct input values. Given the ADC data
+		 * is 10 bit long, it may assume 2^10 distinct values.
+		 * Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2
+		 * return type indicates to the IIO API to divide *val by 2 to
+		 * the power of *val2 when returning from read_raw.
+		 */
+
+		ret = ad7292_vin_range_multiplier(st, chan->channel);
+		if (ret < 0)
+			return ret;
+
+		*val = st->vref_mv * ret;
+		*val2 = 10;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+static const struct iio_info ad7292_info = {
+	.read_raw = ad7292_read_raw,
+};
+
+static void ad7292_regulator_disable(void *data)
+{
+	struct ad7292_state *st = data;
+
+	regulator_disable(st->reg);
+}
+
+static int ad7292_probe(struct spi_device *spi)
+{
+	struct ad7292_state *st;
+	struct iio_dev *indio_dev;
+	struct device_node *child;
+	bool diff_channels = 0;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	st->spi = spi;
+
+	ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID);
+	if (ret != ADI_VENDOR_ID) {
+		dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret);
+		return -EINVAL;
+	}
+
+	spi_set_drvdata(spi, indio_dev);
+
+	st->reg = devm_regulator_get_optional(&spi->dev, "vref");
+	if (!IS_ERR(st->reg)) {
+		ret = regulator_enable(st->reg);
+		if (ret) {
+			dev_err(&spi->dev,
+				"Failed to enable external vref supply\n");
+			return ret;
+		}
+
+		ret = devm_add_action_or_reset(&spi->dev,
+					       ad7292_regulator_disable, st);
+		if (ret) {
+			regulator_disable(st->reg);
+			return ret;
+		}
+
+		ret = regulator_get_voltage(st->reg);
+		if (ret < 0)
+			return ret;
+
+		st->vref_mv = ret / 1000;
+	} else {
+		/* Use the internal voltage reference. */
+		st->vref_mv = 1250;
+	}
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &ad7292_info;
+
+	for_each_available_child_of_node(spi->dev.of_node, child) {
+		diff_channels = of_property_read_bool(child, "diff-channels");
+		if (diff_channels)
+			break;
+	}
+
+	if (diff_channels) {
+		indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff);
+		indio_dev->channels = ad7292_channels_diff;
+	} else {
+		indio_dev->num_channels = ARRAY_SIZE(ad7292_channels);
+		indio_dev->channels = ad7292_channels;
+	}
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ad7292_id_table[] = {
+	{ "ad7292", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad7292_id_table);
+
+static const struct of_device_id ad7292_of_match[] = {
+	{ .compatible = "adi,ad7292" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ad7292_of_match);
+
+static struct spi_driver ad7292_driver = {
+	.driver = {
+		.name = "ad7292",
+		.of_match_table = ad7292_of_match,
+	},
+	.probe = ad7292_probe,
+	.id_table = ad7292_id_table,
+};
+module_spi_driver(ad7292_driver);
+
+MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt1@gmail.com>");
+MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index d3fc39df535d..1e5375235cfe 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -173,7 +173,6 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	struct iio_dev *indio_dev;
 	struct aspeed_adc_data *data;
 	const struct aspeed_adc_model_data *model_data;
-	struct resource *res;
 	const char *clk_parent_name;
 	int ret;
 	u32 adc_engine_control_reg_val;
@@ -185,8 +184,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 	data = iio_priv(indio_dev);
 	data->dev = &pdev->dev;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	data->base = devm_ioremap_resource(&pdev->dev, res);
+	data->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(data->base))
 		return PTR_ERR(data->base);
 
diff --git a/drivers/iio/adc/bcm_iproc_adc.c b/drivers/iio/adc/bcm_iproc_adc.c
index 646ebdc0a8b4..5e396104ac86 100644
--- a/drivers/iio/adc/bcm_iproc_adc.c
+++ b/drivers/iio/adc/bcm_iproc_adc.c
@@ -308,7 +308,7 @@ static int iproc_adc_do_read(struct iio_dev *indio_dev,
 				"IntMask set failed. Read will likely fail.");
 			read_len = -EIO;
 			goto adc_err;
-		};
+		}
 	}
 	regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
 
diff --git a/drivers/iio/adc/cc10001_adc.c b/drivers/iio/adc/cc10001_adc.c
index f93f1d93b80d..fe9257624f16 100644
--- a/drivers/iio/adc/cc10001_adc.c
+++ b/drivers/iio/adc/cc10001_adc.c
@@ -310,7 +310,6 @@ static int cc10001_adc_probe(struct platform_device *pdev)
 	struct device_node *node = pdev->dev.of_node;
 	struct cc10001_adc_device *adc_dev;
 	unsigned long adc_clk_rate;
-	struct resource *res;
 	struct iio_dev *indio_dev;
 	unsigned long channel_map;
 	int ret;
@@ -340,8 +339,7 @@ static int cc10001_adc_probe(struct platform_device *pdev)
 	indio_dev->info = &cc10001_adc_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
+	adc_dev->reg_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(adc_dev->reg_base)) {
 		ret = PTR_ERR(adc_dev->reg_base);
 		goto err_disable_reg;
diff --git a/drivers/iio/adc/dln2-adc.c b/drivers/iio/adc/dln2-adc.c
index 5fa78c273a25..65c7c9329b1c 100644
--- a/drivers/iio/adc/dln2-adc.c
+++ b/drivers/iio/adc/dln2-adc.c
@@ -524,6 +524,10 @@ static int dln2_adc_triggered_buffer_postenable(struct iio_dev *indio_dev)
 	u16 conflict;
 	unsigned int trigger_chan;
 
+	ret = iio_triggered_buffer_postenable(indio_dev);
+	if (ret)
+		return ret;
+
 	mutex_lock(&dln2->mutex);
 
 	/* Enable ADC */
@@ -537,6 +541,7 @@ static int dln2_adc_triggered_buffer_postenable(struct iio_dev *indio_dev)
 				(int)conflict);
 			ret = -EBUSY;
 		}
+		iio_triggered_buffer_predisable(indio_dev);
 		return ret;
 	}
 
@@ -550,6 +555,7 @@ static int dln2_adc_triggered_buffer_postenable(struct iio_dev *indio_dev)
 		mutex_unlock(&dln2->mutex);
 		if (ret < 0) {
 			dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
+			iio_triggered_buffer_predisable(indio_dev);
 			return ret;
 		}
 	} else {
@@ -557,12 +563,12 @@ static int dln2_adc_triggered_buffer_postenable(struct iio_dev *indio_dev)
 		mutex_unlock(&dln2->mutex);
 	}
 
-	return iio_triggered_buffer_postenable(indio_dev);
+	return 0;
 }
 
 static int dln2_adc_triggered_buffer_predisable(struct iio_dev *indio_dev)
 {
-	int ret;
+	int ret, ret2;
 	struct dln2_adc *dln2 = iio_priv(indio_dev);
 
 	mutex_lock(&dln2->mutex);
@@ -577,12 +583,14 @@ static int dln2_adc_triggered_buffer_predisable(struct iio_dev *indio_dev)
 	ret = dln2_adc_set_port_enabled(dln2, false, NULL);
 
 	mutex_unlock(&dln2->mutex);
-	if (ret < 0) {
+	if (ret < 0)
 		dev_dbg(&dln2->pdev->dev, "Problem in %s\n", __func__);
-		return ret;
-	}
 
-	return iio_triggered_buffer_predisable(indio_dev);
+	ret2 = iio_triggered_buffer_predisable(indio_dev);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
 }
 
 static const struct iio_buffer_setup_ops dln2_adc_buffer_setup_ops = {
diff --git a/drivers/iio/adc/ingenic-adc.c b/drivers/iio/adc/ingenic-adc.c
index 7a53c2f8d438..39c0a609fc94 100644
--- a/drivers/iio/adc/ingenic-adc.c
+++ b/drivers/iio/adc/ingenic-adc.c
@@ -428,7 +428,6 @@ static int ingenic_adc_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct iio_dev *iio_dev;
 	struct ingenic_adc *adc;
-	struct resource *mem_base;
 	const struct ingenic_adc_soc_data *soc_data;
 	int ret;
 
@@ -445,8 +444,7 @@ static int ingenic_adc_probe(struct platform_device *pdev)
 	mutex_init(&adc->aux_lock);
 	adc->soc_data = soc_data;
 
-	mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	adc->base = devm_ioremap_resource(dev, mem_base);
+	adc->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(adc->base))
 		return PTR_ERR(adc->base);
 
diff --git a/drivers/iio/adc/lpc18xx_adc.c b/drivers/iio/adc/lpc18xx_adc.c
index e400a95f553d..4c6ac6644dc0 100644
--- a/drivers/iio/adc/lpc18xx_adc.c
+++ b/drivers/iio/adc/lpc18xx_adc.c
@@ -119,7 +119,6 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev;
 	struct lpc18xx_adc *adc;
-	struct resource *res;
 	unsigned int clkdiv;
 	unsigned long rate;
 	int ret;
@@ -133,8 +132,7 @@ static int lpc18xx_adc_probe(struct platform_device *pdev)
 	adc->dev = &pdev->dev;
 	mutex_init(&adc->lock);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	adc->base = devm_ioremap_resource(&pdev->dev, res);
+	adc->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(adc->base))
 		return PTR_ERR(adc->base);
 
diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c
index 7bbb64ca3b32..a4776d924f3a 100644
--- a/drivers/iio/adc/mt6577_auxadc.c
+++ b/drivers/iio/adc/mt6577_auxadc.c
@@ -237,7 +237,6 @@ static int mt6577_auxadc_probe(struct platform_device *pdev)
 {
 	struct mt6577_auxadc_device *adc_dev;
 	unsigned long adc_clk_rate;
-	struct resource *res;
 	struct iio_dev *indio_dev;
 	int ret;
 
@@ -253,8 +252,7 @@ static int mt6577_auxadc_probe(struct platform_device *pdev)
 	indio_dev->channels = mt6577_auxadc_iio_channels;
 	indio_dev->num_channels = ARRAY_SIZE(mt6577_auxadc_iio_channels);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
+	adc_dev->reg_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(adc_dev->reg_base)) {
 		dev_err(&pdev->dev, "failed to get auxadc base address\n");
 		return PTR_ERR(adc_dev->reg_base);
diff --git a/drivers/iio/adc/npcm_adc.c b/drivers/iio/adc/npcm_adc.c
index 910f3585fa54..a6170a37ebe8 100644
--- a/drivers/iio/adc/npcm_adc.c
+++ b/drivers/iio/adc/npcm_adc.c
@@ -183,7 +183,6 @@ static int npcm_adc_probe(struct platform_device *pdev)
 	int irq;
 	u32 div;
 	u32 reg_con;
-	struct resource *res;
 	struct npcm_adc *info;
 	struct iio_dev *indio_dev;
 	struct device *dev = &pdev->dev;
@@ -196,8 +195,7 @@ static int npcm_adc_probe(struct platform_device *pdev)
 
 	info->dev = &pdev->dev;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	info->regs = devm_ioremap_resource(&pdev->dev, res);
+	info->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(info->regs))
 		return PTR_ERR(info->regs);
 
diff --git a/drivers/iio/adc/rcar-gyroadc.c b/drivers/iio/adc/rcar-gyroadc.c
index c37f201294b2..63ce743ee7af 100644
--- a/drivers/iio/adc/rcar-gyroadc.c
+++ b/drivers/iio/adc/rcar-gyroadc.c
@@ -481,7 +481,6 @@ static int rcar_gyroadc_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct rcar_gyroadc *priv;
 	struct iio_dev *indio_dev;
-	struct resource *mem;
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
@@ -491,8 +490,7 @@ static int rcar_gyroadc_probe(struct platform_device *pdev)
 	priv = iio_priv(indio_dev);
 	priv->dev = dev;
 
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	priv->regs = devm_ioremap_resource(dev, mem);
+	priv->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(priv->regs))
 		return PTR_ERR(priv->regs);
 
diff --git a/drivers/iio/adc/spear_adc.c b/drivers/iio/adc/spear_adc.c
index 592b97c464da..0ad536494e8f 100644
--- a/drivers/iio/adc/spear_adc.c
+++ b/drivers/iio/adc/spear_adc.c
@@ -260,7 +260,6 @@ static int spear_adc_probe(struct platform_device *pdev)
 	struct device_node *np = pdev->dev.of_node;
 	struct device *dev = &pdev->dev;
 	struct spear_adc_state *st;
-	struct resource *res;
 	struct iio_dev *indio_dev = NULL;
 	int ret = -ENODEV;
 	int irq;
@@ -279,8 +278,7 @@ static int spear_adc_probe(struct platform_device *pdev)
 	 * (e.g. SPEAr3xx). Let's provide two register base addresses
 	 * to support multi-arch kernels.
 	 */
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	st->adc_base_spear6xx = devm_ioremap_resource(&pdev->dev, res);
+	st->adc_base_spear6xx = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(st->adc_base_spear6xx))
 		return PTR_ERR(st->adc_base_spear6xx);
 
diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
index 20c626c289ed..6537f4f776c5 100644
--- a/drivers/iio/adc/stm32-adc-core.c
+++ b/drivers/iio/adc/stm32-adc-core.c
@@ -79,6 +79,7 @@ struct stm32_adc_priv_cfg {
  * @domain:		irq domain reference
  * @aclk:		clock reference for the analog circuitry
  * @bclk:		bus clock common for all ADCs, depends on part used
+ * @max_clk_rate:	desired maximum clock rate
  * @booster:		booster supply reference
  * @vdd:		vdd supply reference
  * @vdda:		vdda analog supply reference
@@ -95,6 +96,7 @@ struct stm32_adc_priv {
 	struct irq_domain		*domain;
 	struct clk			*aclk;
 	struct clk			*bclk;
+	u32				max_clk_rate;
 	struct regulator		*booster;
 	struct regulator		*vdd;
 	struct regulator		*vdda;
@@ -141,7 +143,7 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev,
 	}
 
 	for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) {
-		if ((rate / stm32f4_pclk_div[i]) <= priv->cfg->max_clk_rate_hz)
+		if ((rate / stm32f4_pclk_div[i]) <= priv->max_clk_rate)
 			break;
 	}
 	if (i >= ARRAY_SIZE(stm32f4_pclk_div)) {
@@ -230,7 +232,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev,
 			if (ckmode)
 				continue;
 
-			if ((rate / div) <= priv->cfg->max_clk_rate_hz)
+			if ((rate / div) <= priv->max_clk_rate)
 				goto out;
 		}
 	}
@@ -250,7 +252,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev,
 		if (!ckmode)
 			continue;
 
-		if ((rate / div) <= priv->cfg->max_clk_rate_hz)
+		if ((rate / div) <= priv->max_clk_rate)
 			goto out;
 	}
 
@@ -655,6 +657,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct device_node *np = pdev->dev.of_node;
 	struct resource *res;
+	u32 max_rate;
 	int ret;
 
 	if (!pdev->dev.of_node)
@@ -731,6 +734,13 @@ static int stm32_adc_probe(struct platform_device *pdev)
 	priv->common.vref_mv = ret / 1000;
 	dev_dbg(&pdev->dev, "vref+=%dmV\n", priv->common.vref_mv);
 
+	ret = of_property_read_u32(pdev->dev.of_node, "st,max-clk-rate-hz",
+				   &max_rate);
+	if (!ret)
+		priv->max_clk_rate = min(max_rate, priv->cfg->max_clk_rate_hz);
+	else
+		priv->max_clk_rate = priv->cfg->max_clk_rate_hz;
+
 	ret = priv->cfg->clk_sel(pdev, priv);
 	if (ret < 0)
 		goto err_hw_stop;
diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
index 98b30475bbc6..cb7380bf07ca 100644
--- a/drivers/iio/adc/vf610_adc.c
+++ b/drivers/iio/adc/vf610_adc.c
@@ -802,7 +802,6 @@ static int vf610_adc_probe(struct platform_device *pdev)
 {
 	struct vf610_adc *info;
 	struct iio_dev *indio_dev;
-	struct resource *mem;
 	int irq;
 	int ret;
 
@@ -815,8 +814,7 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	info = iio_priv(indio_dev);
 	info->dev = &pdev->dev;
 
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	info->regs = devm_ioremap_resource(&pdev->dev, mem);
+	info->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(info->regs))
 		return PTR_ERR(info->regs);