diff options
Diffstat (limited to 'drivers/fpga/lattice-sysconfig-spi.c')
| -rw-r--r-- | drivers/fpga/lattice-sysconfig-spi.c | 153 |
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 000000000..44691cfcf --- /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"); |