[PATCH v12 6/9] iio: adc: adi-axi-adc: set data format

Antoniu Miclaus
2025-02-07T14:10:02Z

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 v12:
- add separate compatible for ad485x AXI IP core.
drivers/iio/adc/adi-axi-adc.c | 99 +++++++++++++++++++++++++++++++----
1 file changed, 90 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index d2e1dc63775c..272d82c6e887 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 AD485X_CNTRL_3_PACKET_FORMAT_MSK GENMASK(1, 0)
+#define AD485X_PACKET_FORMAT_20BIT 0x0
+#define AD485X_PACKET_FORMAT_24BIT 0x1
+#define 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 +324,45 @@ static int axi_adc_interface_type_get(struct iio_backend *back,
return 0;
}

+static int axi_adc_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 AD485X IP block, a 16-bit
+ * and a 20-bit variant.
+ * The 0x0 value (AD485X_PACKET_FORMAT_20BIT) is corresponding also to
+ * the 16-bit variant of the IP block.
+ */
+ case 16:
+ case 20:
+ val = AD485X_PACKET_FORMAT_20BIT;
+ break;
+ case 24:
+ val = AD485X_PACKET_FORMAT_24BIT;
+ break;
+ /*
+ * The 0x2 (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 (AD485X_PACKET_FORMAT_32BIT)
+ * value is handled as maximum size available which is 24-bit for this
+ * configuration.
+ */
+ case 32:
+ val = AD485X_PACKET_FORMAT_32BIT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return regmap_update_bits(st->regmap, ADI_AXI_ADC_REG_CNTRL_3,
+ AD485X_CNTRL_3_PACKET_FORMAT_MSK,
+ FIELD_PREP(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 +415,35 @@ 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_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 +465,8 @@ 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 +486,19 @@ 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 +511,20 @@ 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