[PATCH v3 10/12] spi: offload trigger: add ADI Util Sigma-Delta SPI driver

David Lechner
2025-07-01T21:39:42Z

Add a new driver for the ADI Util Sigma-Delta SPI FPGA IP core.

This is used to trigger a SPI offload based on a RDY signal from an ADC
while masking out other signals on the same line.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
MAINTAINERS | 2 +-
drivers/spi/Kconfig | 5 ++
drivers/spi/Makefile | 1 +
.../spi/spi-offload-trigger-adi-util-sigma-delta.c | 62 ++++++++++++++++++++++
4 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 60ba572be7f5b48c0ab1d0d9724e19e335e8761b..4ed4977deb6ddc545be39b5c1d5e9959e9fe64cf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23357,7 +23357,7 @@ F: include/linux/mtd/spi-nor.h

SPI OFFLOAD
R: David Lechner <dlechner@baylibre.com>
-F: drivers/spi/spi-offload-trigger-pwm.c
+F: drivers/spi/spi-offload-trigger-*.c
F: drivers/spi/spi-offload.c
F: include/linux/spi/offload/
K: spi_offload
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index c51da3fc3604977b05388687e5e64a58370186c4..e69f060d3875c168a2dc701a372e47b8ffd33268 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -1355,6 +1355,11 @@ if SPI_OFFLOAD

comment "SPI Offload triggers"

+config SPI_OFFLOAD_TRIGGER_ADI_UTIL_SD
+ tristate "SPI offload trigger using ADI sigma-delta utility"
+ help
+ SPI offload trigger from ADI sigma-delta utility FPGA IP block.
+
config SPI_OFFLOAD_TRIGGER_PWM
tristate "SPI offload trigger using PWM"
depends on PWM
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 4ea89f6fc531625060255ecff237470927e1f041..51f9f16ed734424ff10672a04f2ec166dc637e0b 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -170,3 +170,4 @@ obj-$(CONFIG_SPI_SLAVE_SYSTEM_CONTROL) += spi-slave-system-control.o

# SPI offload triggers
obj-$(CONFIG_SPI_OFFLOAD_TRIGGER_PWM) += spi-offload-trigger-pwm.o
+obj-$(CONFIG_SPI_OFFLOAD_TRIGGER_ADI_UTIL_SD) += spi-offload-trigger-adi-util-sigma-delta.o
diff --git a/drivers/spi/spi-offload-trigger-adi-util-sigma-delta.c b/drivers/spi/spi-offload-trigger-adi-util-sigma-delta.c
new file mode 100644
index 0000000000000000000000000000000000000000..8468c773713a3d203b2e668f340ee3f477b8fb6c
--- /dev/null
+++ b/drivers/spi/spi-offload-trigger-adi-util-sigma-delta.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Analog Devices Inc.
+ * Copyright (C) 2025 BayLibre, SAS
+ */
+
+#include <linux/clk.h>
+#include <linux/dev_printk.h>
+#include <linux/err.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/spi/offload/provider.h>
+#include <linux/spi/offload/types.h>
+#include <linux/types.h>
+
+static bool adi_util_sigma_delta_match(struct spi_offload_trigger *trigger,
+ enum spi_offload_trigger_type type,
+ u64 *args, u32 nargs)
+{
+ return type == SPI_OFFLOAD_TRIGGER_DATA_READY && nargs == 0;
+}
+
+static const struct spi_offload_trigger_ops adi_util_sigma_delta_ops = {
+ .match = adi_util_sigma_delta_match,
+};
+
+static int adi_util_sigma_delta_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct spi_offload_trigger_info info = {
+ .fwnode = dev_fwnode(dev),
+ .ops = &adi_util_sigma_delta_ops,
+ };
+ struct clk *clk;
+
+ clk = devm_clk_get_enabled(dev, NULL);
+ if (IS_ERR(clk))
+ return dev_err_probe(dev, PTR_ERR(clk), "Failed to get clock\n");
+
+ return devm_spi_offload_trigger_register(dev, &info);
+}
+
+static const struct of_device_id adi_util_sigma_delta_of_match_table[] = {
+ { .compatible = "adi,util-sigma-delta-spi", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, adi_util_sigma_delta_of_match_table);
+
+static struct platform_driver adi_util_sigma_delta_driver = {
+ .probe = adi_util_sigma_delta_probe,
+ .driver = {
+ .name = "adi-util-sigma-delta-spi",
+ .of_match_table = adi_util_sigma_delta_of_match_table,
+ },
+};
+module_platform_driver(adi_util_sigma_delta_driver);
+
+MODULE_AUTHOR("David Lechner <dlechner@baylibre.com>");
+MODULE_DESCRIPTION("ADI Sigma-Delta SPI offload trigger utility driver");
+MODULE_LICENSE("GPL");

--
2.43.0