Add support for selecting the data format within the AXI ADC ip.

Add separate complatible string for the custom AD485X IP and implement
the necessary changes.

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
changes in v13:
 - add AXI_ prefix for macro definitions
 - add _ad485x_ in function header
 drivers/iio/adc/adi-axi-adc.c | 101 +++++++++++++++++++++++++++++++---
 1 file changed, 92 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index d2e1dc63775c..dbd11c2ecf76 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -45,6 +45,12 @@
 #define ADI_AXI_ADC_REG_CTRL			0x0044
 #define    ADI_AXI_ADC_CTRL_DDR_EDGESEL_MASK	BIT(1)
 
+#define ADI_AXI_ADC_REG_CNTRL_3			0x004c
+#define   AXI_AD485X_CNTRL_3_PACKET_FORMAT_MSK	GENMASK(1, 0)
+#define   AXI_AD485X_PACKET_FORMAT_20BIT	0x0
+#define   AXI_AD485X_PACKET_FORMAT_24BIT	0x1
+#define   AXI_AD485X_PACKET_FORMAT_32BIT	0x2
+
 #define ADI_AXI_ADC_REG_DRP_STATUS		0x0074
 #define   ADI_AXI_ADC_DRP_LOCKED		BIT(17)
 
@@ -83,11 +89,17 @@
 	 ADI_AXI_REG_CHAN_CTRL_FMT_EN |		\
 	 ADI_AXI_REG_CHAN_CTRL_ENABLE)
 
+struct axi_adc_info {
+	unsigned int version;
+	const struct iio_backend_info *backend_info;
+};
+
 struct adi_axi_adc_state {
 	struct regmap *regmap;
 	struct device *dev;
 	/* lock to protect multiple accesses to the device registers */
 	struct mutex lock;
+	const struct axi_adc_info *info;
 };
 
 static int axi_adc_enable(struct iio_backend *back)
@@ -312,6 +324,47 @@ static int axi_adc_interface_type_get(struct iio_backend *back,
 	return 0;
 }
 
+static int axi_adc_ad485x_data_size_set(struct iio_backend *back,
+					unsigned int size)
+{
+	struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+	unsigned int val;
+
+	switch (size) {
+	/*
+	 * There are two different variants of the AXI AXI_AD485X IP block, a
+	 * 16-bit and a 20-bit variant.
+	 * The 0x0 value (AXI_AD485X_PACKET_FORMAT_20BIT) is corresponding also
+	 * to the 16-bit variant of the IP block.
+	 */
+	case 16:
+	case 20:
+		val = AXI_AD485X_PACKET_FORMAT_20BIT;
+		break;
+	case 24:
+		val = AXI_AD485X_PACKET_FORMAT_24BIT;
+		break;
+	/*
+	 * The 0x2 (AXI_AD485X_PACKET_FORMAT_32BIT) corresponds only to the
+	 * 20-bit variant of the IP block. Setting this value properly is
+	 * ensured by the upper layers of the drivers calling the axi-adc
+	 * functions.
+	 * Also, for 16-bit IP block, the 0x2 (AXI_AD485X_PACKET_FORMAT_32BIT)
+	 * value is handled as maximum size available which is 24-bit for this
+	 * configuration.
+	 */
+	case 32:
+		val = AXI_AD485X_PACKET_FORMAT_32BIT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(st->regmap, ADI_AXI_ADC_REG_CNTRL_3,
+				  AXI_AD485X_CNTRL_3_PACKET_FORMAT_MSK,
+				  FIELD_PREP(AXI_AD485X_CNTRL_3_PACKET_FORMAT_MSK, val));
+}
+
 static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
 						 struct iio_dev *indio_dev)
 {
@@ -364,14 +417,35 @@ static const struct iio_backend_ops adi_axi_adc_ops = {
 	.debugfs_print_chan_status = iio_backend_debugfs_ptr(axi_adc_debugfs_print_chan_status),
 };
 
+static const struct iio_backend_ops adi_ad485x_ops = {
+	.enable = axi_adc_enable,
+	.disable = axi_adc_disable,
+	.data_format_set = axi_adc_data_format_set,
+	.chan_enable = axi_adc_chan_enable,
+	.chan_disable = axi_adc_chan_disable,
+	.request_buffer = axi_adc_request_buffer,
+	.free_buffer = axi_adc_free_buffer,
+	.data_sample_trigger = axi_adc_data_sample_trigger,
+	.iodelay_set = axi_adc_iodelays_set,
+	.chan_status = axi_adc_chan_status,
+	.interface_type_get = axi_adc_interface_type_get,
+	.data_size_set = axi_adc_ad485x_data_size_set,
+	.debugfs_reg_access = iio_backend_debugfs_ptr(axi_adc_reg_access),
+	.debugfs_print_chan_status = iio_backend_debugfs_ptr(axi_adc_debugfs_print_chan_status),
+};
+
 static const struct iio_backend_info adi_axi_adc_generic = {
 	.name = "axi-adc",
 	.ops = &adi_axi_adc_ops,
 };
 
+static const struct iio_backend_info axi_ad485x = {
+	.name = "axi-ad485x",
+	.ops = &adi_ad485x_ops,
+};
+
 static int adi_axi_adc_probe(struct platform_device *pdev)
 {
-	const unsigned int *expected_ver;
 	struct adi_axi_adc_state *st;
 	void __iomem *base;
 	unsigned int ver;
@@ -393,8 +467,8 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, PTR_ERR(st->regmap),
 				     "failed to init register map\n");
 
-	expected_ver = device_get_match_data(&pdev->dev);
-	if (!expected_ver)
+	st->info = device_get_match_data(&pdev->dev);
+	if (!st->info)
 		return -ENODEV;
 
 	clk = devm_clk_get_enabled(&pdev->dev, NULL);
@@ -414,19 +488,19 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(*expected_ver)) {
+	if (ADI_AXI_PCORE_VER_MAJOR(ver) != ADI_AXI_PCORE_VER_MAJOR(st->info->version)) {
 		dev_err(&pdev->dev,
 			"Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
-			ADI_AXI_PCORE_VER_MAJOR(*expected_ver),
-			ADI_AXI_PCORE_VER_MINOR(*expected_ver),
-			ADI_AXI_PCORE_VER_PATCH(*expected_ver),
+			ADI_AXI_PCORE_VER_MAJOR(st->info->version),
+			ADI_AXI_PCORE_VER_MINOR(st->info->version),
+			ADI_AXI_PCORE_VER_PATCH(st->info->version),
 			ADI_AXI_PCORE_VER_MAJOR(ver),
 			ADI_AXI_PCORE_VER_MINOR(ver),
 			ADI_AXI_PCORE_VER_PATCH(ver));
 		return -ENODEV;
 	}
 
-	ret = devm_iio_backend_register(&pdev->dev, &adi_axi_adc_generic, st);
+	ret = devm_iio_backend_register(&pdev->dev,  st->info->backend_info, st);
 	if (ret)
 		return dev_err_probe(&pdev->dev, ret,
 				     "failed to register iio backend\n");
@@ -439,11 +513,20 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static unsigned int adi_axi_adc_10_0_a_info = ADI_AXI_PCORE_VER(10, 0, 'a');
+static const struct axi_adc_info adi_axi_adc_10_0_a_info = {
+	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
+	.backend_info = &adi_axi_adc_generic,
+};
+
+static const struct axi_adc_info adi_axi_ad485x = {
+	.version = ADI_AXI_PCORE_VER(10, 0, 'a'),
+	.backend_info = &axi_ad485x,
+};
 
 /* Match table for of_platform binding */
 static const struct of_device_id adi_axi_adc_of_match[] = {
 	{ .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
+	{ .compatible = "adi,axi-ad485x", .data = &adi_axi_ad485x },
 	{ /* end of list */ }
 };
 MODULE_DEVICE_TABLE(of, adi_axi_adc_of_match);
-- 
2.48.1

On Fri, 14 Feb 2025 15:19:52 +0200
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Add support for selecting the data format within the AXI ADC ip.
> 
> Add separate complatible string for the custom AD485X IP and implement
> the necessary changes.
> 
> Reviewed-by: Nuno Sa <nuno.sa@analog.com>
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
This also needed hand merging, please check the result.  I shuffled
a few things around to what felt like a more logical ordering to me.

Jonathan