From: Ian Dannapel <iansdannapel@xxxxxxxxx>
Add a new driver for loading binary firmware to configuration
RAM using "SPI passive mode" on Efinix FPGAs.
Signed-off-by: Ian Dannapel <iansdannapel@xxxxxxxxx>
---
drivers/fpga/Kconfig | 7 ++
drivers/fpga/Makefile | 1 +
drivers/fpga/efinix-spi.c | 212 ++++++++++++++++++++++++++++++++++++++
3 files changed, 220 insertions(+)
create mode 100644 drivers/fpga/efinix-spi.c
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 37b35f58f0df..b5d60ba62900 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -83,6 +83,13 @@ config FPGA_MGR_XILINX_SPI
FPGA manager driver support for Xilinx FPGA configuration
over slave serial interface.
+config FPGA_MGR_EFINIX_SPI
+ tristate "Efinix FPGA configuration over SPI"
+ depends on SPI
+ help
+ FPGA manager driver support for Efinix FPGAs configuration over SPI
+ (passive mode only).
+
config FPGA_MGR_ICE40_SPI
tristate "Lattice iCE40 SPI"
depends on OF && SPI
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index aeb89bb13517..adbd51d2cd1e 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_FPGA_MGR_TS73XX) += ts73xx-fpga.o
obj-$(CONFIG_FPGA_MGR_XILINX_CORE) += xilinx-core.o
obj-$(CONFIG_FPGA_MGR_XILINX_SELECTMAP) += xilinx-selectmap.o
obj-$(CONFIG_FPGA_MGR_XILINX_SPI) += xilinx-spi.o
+obj-$(CONFIG_FPGA_MGR_EFINIX_SPI) += efinix-spi.o
obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA) += zynq-fpga.o
obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA) += zynqmp-fpga.o
obj-$(CONFIG_FPGA_MGR_VERSAL_FPGA) += versal-fpga.o
diff --git a/drivers/fpga/efinix-spi.c b/drivers/fpga/efinix-spi.c
new file mode 100644
index 000000000000..07885110a8a8
--- /dev/null
+++ b/drivers/fpga/efinix-spi.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * FPGA Manager Driver for Efinix
+ *
+ * Copyright (C) 2025 iris-GmbH infrared & intelligent sensors
+ *
+ * Ian Dannapel <iansdannapel@xxxxxxxxx>
+ *
+ * Load Efinix FPGA firmware over SPI using the serial configuration interface.
+ *
+ * Note 1: Only passive mode (host initiates transfer) is currently supported.
+ * Note 2: Topaz and Titanium support is based on documentation but remains
+ * untested.
+ */
+
+#include <linux/delay.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/spi/spi.h>
+
+struct efinix_spi_conf {
+ struct spi_device *spi;
+ struct gpio_desc *cdone;
+ struct gpio_desc *reset;
+};
+
+static void efinix_spi_reset(struct efinix_spi_conf *conf)
+{
+ gpiod_set_value(conf->reset, 1);
+ /* tCRESET_N > 320 ns */
+ usleep_range(1, 2);
+ gpiod_set_value(conf->reset, 0);
+
+ /* tDMIN > 32 us */
+ usleep_range(35, 40);
+}
+
+static enum fpga_mgr_states efinix_spi_state(struct fpga_manager *mgr)
+{
+ struct efinix_spi_conf *conf = mgr->priv;
+
+ if (conf->cdone && gpiod_get_value(conf->cdone) == 1)
+ return FPGA_MGR_STATE_OPERATING;
+
+ return FPGA_MGR_STATE_UNKNOWN;
+}
+
+static int efinix_spi_write_init(struct fpga_manager *mgr,
+ struct fpga_image_info *info,
+ const char *buf, size_t count)
+{
+ if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
+ dev_err(&mgr->dev, "Partial reconfiguration not supported\n");
+ return -EOPNOTSUPP;
+ }
+ return 0;
+}
+
+static int efinix_spi_write(struct fpga_manager *mgr, const char *buf,
+ size_t count)
+{
+ struct efinix_spi_conf *conf = mgr->priv;
+ int ret;
+ struct spi_message message;
+ struct spi_transfer assert_cs = {
+ .cs_change = 1
+ };
+ struct spi_transfer write_xfer = {
+ .tx_buf = buf,
+ .len = count
+ };
+ struct spi_transfer clk_cycles = {
+ .len = 13, // > 100 clock cycles
+ .tx_buf = NULL
+ };
+ u8 *dummy_buf;
+
+ dummy_buf = kzalloc(13, GFP_KERNEL);
+ if (!dummy_buf) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ spi_bus_lock(conf->spi->controller);
+ spi_message_init(&message);
+ spi_message_add_tail(&assert_cs, &message);
+ ret = spi_sync_locked(conf->spi, &message);
+ if (ret)
+ goto fail_unlock;
+
+ /* reset with asserted cs */
+ efinix_spi_reset(conf);
+
+ spi_message_init(&message);
+ spi_message_add_tail(&write_xfer, &message);
+
+ clk_cycles.tx_buf = dummy_buf;
+ spi_message_add_tail(&clk_cycles, &message);
+
+ ret = spi_sync_locked(conf->spi, &message);
+ if (ret)
+ dev_err(&mgr->dev, "SPI error in firmware write: %d\n", ret);
+
+fail_unlock:
+ spi_bus_unlock(conf->spi->controller);
+ kfree(dummy_buf);
+fail:
+ return ret;
+}
+
+static int efinix_spi_write_complete(struct fpga_manager *mgr,
+ struct fpga_image_info *info)
+{
+ struct efinix_spi_conf *conf = mgr->priv;
+ unsigned long timeout =
+ jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+ bool expired = false;
+ int done;
+
+ if (conf->cdone) {
+ while (!expired) {
+ expired = time_after(jiffies, timeout);
+
+ done = gpiod_get_value(conf->cdone);
+ if (done < 0)
+ return done;
+
+ if (done)
+ break;
+ }
+ }
+
+ if (expired)
+ return -ETIMEDOUT;
+
+ /* tUSER > 25 us */
+ usleep_range(30, 35);
+ return 0;
+}
+
+static const struct fpga_manager_ops efinix_spi_ops = {
+ .state = efinix_spi_state,
+ .write_init = efinix_spi_write_init,
+ .write = efinix_spi_write,
+ .write_complete = efinix_spi_write_complete,
+};
+
+static int efinix_spi_probe(struct spi_device *spi)
+{
+ struct efinix_spi_conf *conf;
+ struct fpga_manager *mgr;
+
+ conf = devm_kzalloc(&spi->dev, sizeof(*conf), GFP_KERNEL);
+ if (!conf)
+ return -ENOMEM;
+
+ conf->spi = spi;
+
+ conf->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(conf->reset))
+ return dev_err_probe(&spi->dev, PTR_ERR(conf->reset),
+ "Failed to get RESET gpio\n");
+
+ if (!(spi->mode & SPI_CPHA) || !(spi->mode & SPI_CPOL))
+ return dev_err_probe(&spi->dev, -EINVAL,
+ "Unsupported SPI mode, set CPHA and CPOL\n");
+
+ conf->cdone = devm_gpiod_get_optional(&spi->dev, "cdone", GPIOD_IN);
+ if (IS_ERR(conf->cdone))
+ return dev_err_probe(&spi->dev, PTR_ERR(conf->cdone),
+ "Failed to get CDONE gpio\n");
+
+ mgr = devm_fpga_mgr_register(&spi->dev,
+ "Efinix FPGA Manager",
+ &efinix_spi_ops, conf);
+
+ return PTR_ERR_OR_ZERO(mgr);
+}
+
+static const struct of_device_id efinix_spi_of_match[] = {
+ { .compatible = "efinix,trion-spi", },
+ { .compatible = "efinix,titanium-spi", },
+ { .compatible = "efinix,topaz-spi", },
+ { .compatible = "efinix,fpga-spi", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, efinix_spi_of_match);
+
+static const struct spi_device_id efinix_ids[] = {
+ { "trion-spi", 0 },
+ { "titanium-spi", 0 },
+ { "topaz-spi", 0 },
+ {},
+};
+MODULE_DEVICE_TABLE(spi, efinix_ids);
+
+static struct spi_driver efinix_spi_driver = {
+ .driver = {
+ .name = "efinix-spi",
+ .of_match_table = efinix_spi_of_match,
+ },
+ .probe = efinix_spi_probe,
+ .id_table = efinix_ids,
+};
+
+module_spi_driver(efinix_spi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ian Dannapel <iansdannapel@xxxxxxxxx>");
+MODULE_DESCRIPTION("Efinix FPGA SPI Programming Driver (Topaz/Titanium untested)");
--
2.43.0
