summaryrefslogtreecommitdiffstats
path: root/drivers/fpga/lattice-sysconfig-spi.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/fpga/lattice-sysconfig-spi.c')
-rw-r--r--drivers/fpga/lattice-sysconfig-spi.c153
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/fpga/lattice-sysconfig-spi.c b/drivers/fpga/lattice-sysconfig-spi.c
new file mode 100644
index 0000000000..44691cfcf5
--- /dev/null
+++ b/drivers/fpga/lattice-sysconfig-spi.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Lattice FPGA programming over slave SPI sysCONFIG interface.
+ */
+
+#include <linux/of.h>
+#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");