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authorJoel Holdsworth <joel@airwebreathe.org.uk>2017-02-27 16:14:26 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-17 15:10:48 +0900
commit21f8ba2ef378d906374a26f7abc05fb92219e9c6 (patch)
treef2acb4c44b5b0ca266d14194bd8e522d6d1b8295 /drivers/fpga
parente10c11d2739fd3657d8d1d5b1fa06f9185b4f012 (diff)
fpga: Add support for Lattice iCE40 FPGAs
This patch adds support to the FPGA manager for configuring the SRAM of iCE40LM, iCE40LP, iCE40HX, iCE40 Ultra, iCE40 UltraLite and iCE40 UltraPlus devices, through slave SPI. Signed-off-by: Joel Holdsworth <joel@airwebreathe.org.uk> Reviewed-by: Marek Vasut <marex@denx.de> Reviewed-by: Moritz Fischer <moritz.fischer@ettus.com> Acked-by: Alan Tull <atull@opensource.altera.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/fpga')
-rw-r--r--drivers/fpga/Kconfig6
-rw-r--r--drivers/fpga/Makefile1
-rw-r--r--drivers/fpga/ice40-spi.c207
3 files changed, 214 insertions, 0 deletions
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index d9cbef60db80..dee470f9113f 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -20,6 +20,12 @@ config FPGA_REGION
FPGA Regions allow loading FPGA images under control of
the Device Tree.
+config FPGA_MGR_ICE40_SPI
+ tristate "Lattice iCE40 SPI"
+ depends on OF && SPI
+ help
+ FPGA manager driver support for Lattice iCE40 FPGAs over SPI.
+
config FPGA_MGR_SOCFPGA
tristate "Altera SOCFPGA FPGA Manager"
depends on ARCH_SOCFPGA || COMPILE_TEST
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index a1160169e6d9..a5ee3ffe8b18 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -6,6 +6,7 @@
obj-$(CONFIG_FPGA) += fpga-mgr.o
# FPGA Manager Drivers
+obj-$(CONFIG_FPGA_MGR_ICE40_SPI) += ice40-spi.o
obj-$(CONFIG_FPGA_MGR_SOCFPGA) += socfpga.o
obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10) += socfpga-a10.o
obj-$(CONFIG_FPGA_MGR_TS73XX) += ts73xx-fpga.o
diff --git a/drivers/fpga/ice40-spi.c b/drivers/fpga/ice40-spi.c
new file mode 100644
index 000000000000..7fca82023062
--- /dev/null
+++ b/drivers/fpga/ice40-spi.c
@@ -0,0 +1,207 @@
+/*
+ * FPGA Manager Driver for Lattice iCE40.
+ *
+ * Copyright (c) 2016 Joel Holdsworth
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This driver adds support to the FPGA manager for configuring the SRAM of
+ * Lattice iCE40 FPGAs through slave SPI.
+ */
+
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/spi/spi.h>
+#include <linux/stringify.h>
+
+#define ICE40_SPI_MAX_SPEED 25000000 /* Hz */
+#define ICE40_SPI_MIN_SPEED 1000000 /* Hz */
+
+#define ICE40_SPI_RESET_DELAY 1 /* us (>200ns) */
+#define ICE40_SPI_HOUSEKEEPING_DELAY 1200 /* us */
+
+#define ICE40_SPI_NUM_ACTIVATION_BYTES DIV_ROUND_UP(49, 8)
+
+struct ice40_fpga_priv {
+ struct spi_device *dev;
+ struct gpio_desc *reset;
+ struct gpio_desc *cdone;
+};
+
+static enum fpga_mgr_states ice40_fpga_ops_state(struct fpga_manager *mgr)
+{
+ struct ice40_fpga_priv *priv = mgr->priv;
+
+ return gpiod_get_value(priv->cdone) ? FPGA_MGR_STATE_OPERATING :
+ FPGA_MGR_STATE_UNKNOWN;
+}
+
+static int ice40_fpga_ops_write_init(struct fpga_manager *mgr,
+ struct fpga_image_info *info,
+ const char *buf, size_t count)
+{
+ struct ice40_fpga_priv *priv = mgr->priv;
+ struct spi_device *dev = priv->dev;
+ struct spi_message message;
+ struct spi_transfer assert_cs_then_reset_delay = {
+ .cs_change = 1,
+ .delay_usecs = ICE40_SPI_RESET_DELAY
+ };
+ struct spi_transfer housekeeping_delay_then_release_cs = {
+ .delay_usecs = ICE40_SPI_HOUSEKEEPING_DELAY
+ };
+ int ret;
+
+ if ((info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
+ dev_err(&dev->dev,
+ "Partial reconfiguration is not supported\n");
+ return -ENOTSUPP;
+ }
+
+ /* Lock the bus, assert CRESET_B and SS_B and delay >200ns */
+ spi_bus_lock(dev->master);
+
+ gpiod_set_value(priv->reset, 1);
+
+ spi_message_init(&message);
+ spi_message_add_tail(&assert_cs_then_reset_delay, &message);
+ ret = spi_sync_locked(dev, &message);
+
+ /* Come out of reset */
+ gpiod_set_value(priv->reset, 0);
+
+ /* Abort if the chip-select failed */
+ if (ret)
+ goto fail;
+
+ /* Check CDONE is de-asserted i.e. the FPGA is reset */
+ if (gpiod_get_value(priv->cdone)) {
+ dev_err(&dev->dev, "Device reset failed, CDONE is asserted\n");
+ ret = -EIO;
+ goto fail;
+ }
+
+ /* Wait for the housekeeping to complete, and release SS_B */
+ spi_message_init(&message);
+ spi_message_add_tail(&housekeeping_delay_then_release_cs, &message);
+ ret = spi_sync_locked(dev, &message);
+
+fail:
+ spi_bus_unlock(dev->master);
+
+ return ret;
+}
+
+static int ice40_fpga_ops_write(struct fpga_manager *mgr,
+ const char *buf, size_t count)
+{
+ struct ice40_fpga_priv *priv = mgr->priv;
+
+ return spi_write(priv->dev, buf, count);
+}
+
+static int ice40_fpga_ops_write_complete(struct fpga_manager *mgr,
+ struct fpga_image_info *info)
+{
+ struct ice40_fpga_priv *priv = mgr->priv;
+ struct spi_device *dev = priv->dev;
+ const u8 padding[ICE40_SPI_NUM_ACTIVATION_BYTES] = {0};
+
+ /* Check CDONE is asserted */
+ if (!gpiod_get_value(priv->cdone)) {
+ dev_err(&dev->dev,
+ "CDONE was not asserted after firmware transfer\n");
+ return -EIO;
+ }
+
+ /* Send of zero-padding to activate the firmware */
+ return spi_write(dev, padding, sizeof(padding));
+}
+
+static const struct fpga_manager_ops ice40_fpga_ops = {
+ .state = ice40_fpga_ops_state,
+ .write_init = ice40_fpga_ops_write_init,
+ .write = ice40_fpga_ops_write,
+ .write_complete = ice40_fpga_ops_write_complete,
+};
+
+static int ice40_fpga_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct ice40_fpga_priv *priv;
+ int ret;
+
+ priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = spi;
+
+ /* Check board setup data. */
+ if (spi->max_speed_hz > ICE40_SPI_MAX_SPEED) {
+ dev_err(dev, "SPI speed is too high, maximum speed is "
+ __stringify(ICE40_SPI_MAX_SPEED) "\n");
+ return -EINVAL;
+ }
+
+ if (spi->max_speed_hz < ICE40_SPI_MIN_SPEED) {
+ dev_err(dev, "SPI speed is too low, minimum speed is "
+ __stringify(ICE40_SPI_MIN_SPEED) "\n");
+ return -EINVAL;
+ }
+
+ if (spi->mode & SPI_CPHA) {
+ dev_err(dev, "Bad SPI mode, CPHA not supported\n");
+ return -EINVAL;
+ }
+
+ /* Set up the GPIOs */
+ priv->cdone = devm_gpiod_get(dev, "cdone", GPIOD_IN);
+ if (IS_ERR(priv->cdone)) {
+ ret = PTR_ERR(priv->cdone);
+ dev_err(dev, "Failed to get CDONE GPIO: %d\n", ret);
+ return ret;
+ }
+
+ priv->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(priv->reset)) {
+ ret = PTR_ERR(priv->reset);
+ dev_err(dev, "Failed to get CRESET_B GPIO: %d\n", ret);
+ return ret;
+ }
+
+ /* Register with the FPGA manager */
+ return fpga_mgr_register(dev, "Lattice iCE40 FPGA Manager",
+ &ice40_fpga_ops, priv);
+}
+
+static int ice40_fpga_remove(struct spi_device *spi)
+{
+ fpga_mgr_unregister(&spi->dev);
+ return 0;
+}
+
+static const struct of_device_id ice40_fpga_of_match[] = {
+ { .compatible = "lattice,ice40-fpga-mgr", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ice40_fpga_of_match);
+
+static struct spi_driver ice40_fpga_driver = {
+ .probe = ice40_fpga_probe,
+ .remove = ice40_fpga_remove,
+ .driver = {
+ .name = "ice40spi",
+ .of_match_table = of_match_ptr(ice40_fpga_of_match),
+ },
+};
+
+module_spi_driver(ice40_fpga_driver);
+
+MODULE_AUTHOR("Joel Holdsworth <joel@airwebreathe.org.uk>");
+MODULE_DESCRIPTION("Lattice iCE40 FPGA Manager");
+MODULE_LICENSE("GPL v2");

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