[PATCH 5/8] iio: dac: adi-axi-dac: add bus mode setup

[Angelo Dureghello <adureghello@xxxxxxxxxxxx>]

From: Angelo Dureghello <adureghello@xxxxxxxxxxxx>

The ad354xr requires DSPI mode to work in buffering mode, so
backend needs to allow a mode selection between:
    SPI  (entire ad35xxr family),
    DSPI (ad354xr),
    QSPI (ad355xr).

Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
 drivers/iio/dac/adi-axi-dac.c | 46 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
index d02eb535b648..f7d22409e9b3 100644
--- a/drivers/iio/dac/adi-axi-dac.c
+++ b/drivers/iio/dac/adi-axi-dac.c
@@ -64,7 +64,7 @@
 #define   AXI_DAC_UI_STATUS_IF_BUSY		BIT(4)
 #define AXI_DAC_CUSTOM_CTRL_REG			0x008C
 #define   AXI_DAC_CUSTOM_CTRL_ADDRESS		GENMASK(31, 24)
-#define   AXI_DAC_CUSTOM_CTRL_SYNCED_TRANSFER	BIT(2)
+#define   AXI_DAC_CUSTOM_CTRL_MULTI_IO_MODE	GENMASK(3, 2)
 #define   AXI_DAC_CUSTOM_CTRL_STREAM		BIT(1)
 #define   AXI_DAC_CUSTOM_CTRL_TRANSFER_DATA	BIT(0)
 
@@ -95,6 +95,12 @@ enum {
 	AXI_DAC_DATA_INTERNAL_RAMP_16BIT = 11,
 };
 
+enum multi_io_mode {
+	AXI_DAC_MULTI_IO_MODE_SPI,
+	AXI_DAC_MULTI_IO_MODE_DSPI,
+	AXI_DAC_MULTI_IO_MODE_QSPI,
+};
+
 struct axi_dac_info {
 	unsigned int version;
 	const struct iio_backend_info *backend_info;
@@ -725,6 +731,43 @@ static int axi_dac_bus_reg_read(struct iio_backend *back, u32 reg, u32 *val,
 	return regmap_read(st->regmap, AXI_DAC_CUSTOM_RD_REG, val);
 }
 
+static int axi_dac_interface_type_set(struct iio_backend *back,
+				      enum iio_backend_interface_type type)
+{
+	struct axi_dac_state *st = iio_backend_get_priv(back);
+	int mode, ival, ret;
+
+	switch (type) {
+	case IIO_BACKEND_INTERFACE_SERIAL_SPI:
+		mode = AXI_DAC_MULTI_IO_MODE_SPI;
+		break;
+	case IIO_BACKEND_INTERFACE_SERIAL_DSPI:
+		mode = AXI_DAC_MULTI_IO_MODE_DSPI;
+		break;
+	case IIO_BACKEND_INTERFACE_SERIAL_QSPI:
+		mode = AXI_DAC_MULTI_IO_MODE_QSPI;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = regmap_update_bits(st->regmap, AXI_DAC_CUSTOM_CTRL_REG,
+			AXI_DAC_CUSTOM_CTRL_MULTI_IO_MODE,
+			FIELD_PREP(AXI_DAC_CUSTOM_CTRL_MULTI_IO_MODE, mode));
+	if (ret)
+		return ret;
+
+	ret = regmap_read_poll_timeout(st->regmap,
+			AXI_DAC_UI_STATUS_REG, ival,
+			FIELD_GET(AXI_DAC_UI_STATUS_IF_BUSY, ival) == 0,
+			10, 100 * KILO);
+
+	if (ret == -ETIMEDOUT)
+		dev_err(st->dev, "AXI read timeout\n");
+
+	return ret;
+}
+
 static void axi_dac_child_remove(void *data)
 {
 	platform_device_unregister(data);
@@ -774,6 +817,7 @@ static const struct iio_backend_ops axi_ad3552r_ops = {
 	.request_buffer = axi_dac_request_buffer,
 	.free_buffer = axi_dac_free_buffer,
 	.data_source_set = axi_dac_data_source_set,
+	.interface_type_set = axi_dac_interface_type_set,
 	.ddr_enable = axi_dac_ddr_enable,
 	.ddr_disable = axi_dac_ddr_disable,
 	.data_stream_enable = axi_dac_data_stream_enable,

-- 
2.47.0