1 files changed, 152 insertions, 0 deletions
diff --git a/drivers/fpga/lattice-sysconfig-spi.c b/drivers/fpga/lattice-sysconfig-spi.c
new file mode 100644
index 000000000000..2702b26b7f55
--- /dev/null
+++ b/drivers/fpga/lattice-sysconfig-spi.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Lattice FPGA programming over slave SPI sysCONFIG interface.
+ */
+
+#include <linux/spi/spi.h>
+
+#include "lattice-sysconfig.h"
+
+static const u32 ecp5_spi_max_speed_hz = 60000000;
+
+static int sysconfig_spi_cmd_transfer(struct sysconfig_priv *priv,
+				      const void *tx_buf, size_t tx_len,
+				      void *rx_buf, size_t rx_len)
+{
+	struct spi_device *spi = to_spi_device(priv->dev);
+
+	return spi_write_then_read(spi, tx_buf, tx_len, rx_buf, rx_len);
+}
+
+static int sysconfig_spi_bitstream_burst_init(struct sysconfig_priv *priv)
+{
+	const u8 lsc_bitstream_burst[] = SYSCONFIG_LSC_BITSTREAM_BURST;
+	struct spi_device *spi = to_spi_device(priv->dev);
+	struct spi_transfer xfer = {};
+	struct spi_message msg;
+	size_t buf_len;
+	void *buf;
+	int ret;
+
+	buf_len = sizeof(lsc_bitstream_burst);
+
+	buf = kmemdup(lsc_bitstream_burst, buf_len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	xfer.len = buf_len;
+	xfer.tx_buf = buf;
+	xfer.cs_change = 1;
+
+	spi_message_init_with_transfers(&msg, &xfer, 1);
+
+	/*
+	 * Lock SPI bus for exclusive usage until FPGA programming is done.
+	 * SPI bus will be released in sysconfig_spi_bitstream_burst_complete().
+	 */
+	spi_bus_lock(spi->controller);
+
+	ret = spi_sync_locked(spi, &msg);
+	if (ret)
+		spi_bus_unlock(spi->controller);
+
+	kfree(buf);
+
+	return ret;
+}
+
+static int sysconfig_spi_bitstream_burst_write(struct sysconfig_priv *priv,
+					       const char *buf, size_t len)
+{
+	struct spi_device *spi = to_spi_device(priv->dev);
+	struct spi_transfer xfer = {
+		.tx_buf = buf,
+		.len = len,
+		.cs_change = 1,
+	};
+	struct spi_message msg;
+
+	spi_message_init_with_transfers(&msg, &xfer, 1);
+
+	return spi_sync_locked(spi, &msg);
+}
+
+static int sysconfig_spi_bitstream_burst_complete(struct sysconfig_priv *priv)
+{
+	struct spi_device *spi = to_spi_device(priv->dev);
+
+	/* Bitstream burst write is done, release SPI bus */
+	spi_bus_unlock(spi->controller);
+
+	/* Toggle CS to finish bitstream write */
+	return spi_write(spi, NULL, 0);
+}
+
+static int sysconfig_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *dev_id;
+	struct device *dev = &spi->dev;
+	struct sysconfig_priv *priv;
+	const u32 *spi_max_speed;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	spi_max_speed = device_get_match_data(dev);
+	if (!spi_max_speed) {
+		dev_id = spi_get_device_id(spi);
+		if (!dev_id)
+			return -ENODEV;
+
+		spi_max_speed = (const u32 *)dev_id->driver_data;
+	}
+
+	if (!spi_max_speed)
+		return -EINVAL;
+
+	if (spi->max_speed_hz > *spi_max_speed) {
+		dev_err(dev, "SPI speed %u is too high, maximum speed is %u\n",
+			spi->max_speed_hz, *spi_max_speed);
+		return -EINVAL;
+	}
+
+	priv->dev = dev;
+	priv->command_transfer = sysconfig_spi_cmd_transfer;
+	priv->bitstream_burst_write_init = sysconfig_spi_bitstream_burst_init;
+	priv->bitstream_burst_write = sysconfig_spi_bitstream_burst_write;
+	priv->bitstream_burst_write_complete = sysconfig_spi_bitstream_burst_complete;
+
+	return sysconfig_probe(priv);
+}
+
+static const struct spi_device_id sysconfig_spi_ids[] = {
+	{
+		.name = "sysconfig-ecp5",
+		.driver_data = (kernel_ulong_t)&ecp5_spi_max_speed_hz,
+	}, {},
+};
+MODULE_DEVICE_TABLE(spi, sysconfig_spi_ids);
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id sysconfig_of_ids[] = {
+	{
+		.compatible = "lattice,sysconfig-ecp5",
+		.data = &ecp5_spi_max_speed_hz,
+	}, {},
+};
+MODULE_DEVICE_TABLE(of, sysconfig_of_ids);
+#endif /* IS_ENABLED(CONFIG_OF) */
+
+static struct spi_driver lattice_sysconfig_driver = {
+	.probe = sysconfig_spi_probe,
+	.id_table = sysconfig_spi_ids,
+	.driver = {
+		.name = "lattice_sysconfig_spi_fpga_mgr",
+		.of_match_table = of_match_ptr(sysconfig_of_ids),
+	},
+};
+module_spi_driver(lattice_sysconfig_driver);
+
+MODULE_DESCRIPTION("Lattice sysCONFIG Slave SPI FPGA Manager");
+MODULE_LICENSE("GPL");