iio: adc: ad9467: add support for AD9265 high-speed ADC

The AD9265 is a 16-bit, 125 MSPS analog-to-digital converter (ADC). The
AD9265 is designed to support communications applications where high
performance combined with low cost, small size, and versatility is
desired.

The ADC core features a multistage, differential pipelined architecture
with integrated output error correction logic to provide 16-bit accuracy at
125 MSPS data rates and guarantees no missing codes over the full operating
temperature range.

The ADC features a wide bandwidth differential sample-and-hold analog input
amplifier supporting a variety of user-selectable input ranges. It is
suitable for multiplexed systems that switch full-scale voltage levels in
successive channels and for sampling single-channel inputs at frequencies
well beyond the Nyquist rate. Combined with power and cost savings over
previously available ADCs, the AD9265 is suitable for applications in
communications, instrumentation and medical imaging.

Link: https://www.analog.com/media/en/technical-documentation/data-sheets/AD9434.pdf

The driver supports the same register set as the AD9467, so the support for
this chip is added to the 'ad9467' driver.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200924080518.96410-4-alexandru.ardelean@analog.com

drivers/iio/adc/ad9467.c

@@ -76,6 +76,14 @@
 /* AN877_ADC_REG_OUTPUT_DELAY */
 #define AN877_ADC_DCO_DELAY_ENABLE		0x80
 
+/*
+ * Analog Devices AD9265 16-Bit, 125/105/80 MSPS ADC
+ */
+
+#define CHIPID_AD9265			0x64
+#define AD9265_DEF_OUTPUT_MODE		0x40
+#define AD9265_REG_VREF_MASK		0xC0
+
 /*
  * Analog Devices AD9434 12-Bit, 370/500 MSPS ADC
  */
@@ -93,6 +101,7 @@
 #define AD9467_REG_VREF_MASK		0x0F
 
 enum {
+	ID_AD9265,
 	ID_AD9434,
 	ID_AD9467,
 };
@@ -167,6 +176,10 @@ static int ad9467_reg_access(struct adi_axi_adc_conv *conv, unsigned int reg,
 	return 0;
 }
 
+static const unsigned int ad9265_scale_table[][2] = {
+	{1250, 0x00}, {1500, 0x40}, {1750, 0x80}, {2000, 0xC0},
+};
+
 static const unsigned int ad9434_scale_table[][2] = {
 	{1600, 0x1C}, {1580, 0x1D}, {1550, 0x1E}, {1520, 0x1F}, {1500, 0x00},
 	{1470, 0x01}, {1440, 0x02}, {1420, 0x03}, {1390, 0x04}, {1360, 0x05},
@@ -216,6 +229,18 @@ static const struct iio_chan_spec ad9467_channels[] = {
 };
 
 static const struct ad9467_chip_info ad9467_chip_tbl[] = {
+	[ID_AD9265] = {
+		.axi_adc_info = {
+			.id = CHIPID_AD9265,
+			.max_rate = 125000000UL,
+			.scale_table = ad9265_scale_table,
+			.num_scales = ARRAY_SIZE(ad9265_scale_table),
+			.channels = ad9467_channels,
+			.num_channels = ARRAY_SIZE(ad9467_channels),
+		},
+		.default_output_mode = AD9265_DEF_OUTPUT_MODE,
+		.vref_mask = AD9265_REG_VREF_MASK,
+	},
 	[ID_AD9434] = {
 		.axi_adc_info = {
 			.id = CHIPID_AD9434,
@@ -432,6 +457,7 @@ static int ad9467_probe(struct spi_device *spi)
 }
 
 static const struct of_device_id ad9467_of_match[] = {
+	{ .compatible = "adi,ad9265", .data = &ad9467_chip_tbl[ID_AD9265], },
 	{ .compatible = "adi,ad9434", .data = &ad9467_chip_tbl[ID_AD9434], },
 	{ .compatible = "adi,ad9467", .data = &ad9467_chip_tbl[ID_AD9467], },
 	{}