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authorAnatolij Gustschin <agust@denx.de>2017-03-23 19:34:26 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-04-08 17:45:28 +0200
commit061c97d13f1a69c0edcab4dc6e97788e5bf3230f (patch)
tree450bb6e43e267d4de22de9b6c9a3775d624b7295 /drivers/fpga
parent12cc5a123a173d6236903af6f3d9d44c81723751 (diff)
fpga manager: Add Xilinx slave serial SPI driver
The driver loads FPGA firmware over SPI, using the "slave serial" configuration interface on Xilinx FPGAs. Signed-off-by: Anatolij Gustschin <agust@denx.de> Acked-by: Michal Simek <michal.simek@xilinx.com> Reviewed-by: Moritz Fischer <mdf@kernel.org> Acked-by: Alan Tull <atull@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/fpga')
-rw-r--r--drivers/fpga/Kconfig7
-rw-r--r--drivers/fpga/Makefile1
-rw-r--r--drivers/fpga/xilinx-spi.c198
3 files changed, 206 insertions, 0 deletions
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index dee470f9113f..c81cb7d9fbd5 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -46,6 +46,13 @@ config FPGA_MGR_TS73XX
FPGA manager driver support for the Altera Cyclone II FPGA
present on the TS-73xx SBC boards.
+config FPGA_MGR_XILINX_SPI
+ tristate "Xilinx Configuration over Slave Serial (SPI)"
+ depends on SPI
+ help
+ FPGA manager driver support for Xilinx FPGA configuration
+ over slave serial interface.
+
config FPGA_MGR_ZYNQ_FPGA
tristate "Xilinx Zynq FPGA"
depends on ARCH_ZYNQ || COMPILE_TEST
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index a5ee3ffe8b18..c6f5d740b946 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -10,6 +10,7 @@ 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
+obj-$(CONFIG_FPGA_MGR_XILINX_SPI) += xilinx-spi.o
obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA) += zynq-fpga.o
# FPGA Bridge Drivers
diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
new file mode 100644
index 000000000000..9b62a4c2a3df
--- /dev/null
+++ b/drivers/fpga/xilinx-spi.c
@@ -0,0 +1,198 @@
+/*
+ * Xilinx Spartan6 Slave Serial SPI Driver
+ *
+ * Copyright (C) 2017 DENX Software Engineering
+ *
+ * Anatolij Gustschin <agust@denx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * Manage Xilinx FPGA firmware that is loaded over SPI using
+ * the slave serial configuration interface.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of.h>
+#include <linux/spi/spi.h>
+#include <linux/sizes.h>
+
+struct xilinx_spi_conf {
+ struct spi_device *spi;
+ struct gpio_desc *prog_b;
+ struct gpio_desc *done;
+};
+
+static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
+{
+ struct xilinx_spi_conf *conf = mgr->priv;
+
+ if (!gpiod_get_value(conf->done))
+ return FPGA_MGR_STATE_RESET;
+
+ return FPGA_MGR_STATE_UNKNOWN;
+}
+
+static int xilinx_spi_write_init(struct fpga_manager *mgr,
+ struct fpga_image_info *info,
+ const char *buf, size_t count)
+{
+ struct xilinx_spi_conf *conf = mgr->priv;
+ const size_t prog_latency_7500us = 7500;
+ const size_t prog_pulse_1us = 1;
+
+ if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
+ dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
+ return -EINVAL;
+ }
+
+ gpiod_set_value(conf->prog_b, 1);
+
+ udelay(prog_pulse_1us); /* min is 500 ns */
+
+ gpiod_set_value(conf->prog_b, 0);
+
+ if (gpiod_get_value(conf->done)) {
+ dev_err(&mgr->dev, "Unexpected DONE pin state...\n");
+ return -EIO;
+ }
+
+ /* program latency */
+ usleep_range(prog_latency_7500us, prog_latency_7500us + 100);
+ return 0;
+}
+
+static int xilinx_spi_write(struct fpga_manager *mgr, const char *buf,
+ size_t count)
+{
+ struct xilinx_spi_conf *conf = mgr->priv;
+ const char *fw_data = buf;
+ const char *fw_data_end = fw_data + count;
+
+ while (fw_data < fw_data_end) {
+ size_t remaining, stride;
+ int ret;
+
+ remaining = fw_data_end - fw_data;
+ stride = min_t(size_t, remaining, SZ_4K);
+
+ ret = spi_write(conf->spi, fw_data, stride);
+ if (ret) {
+ dev_err(&mgr->dev, "SPI error in firmware write: %d\n",
+ ret);
+ return ret;
+ }
+ fw_data += stride;
+ }
+
+ return 0;
+}
+
+static int xilinx_spi_apply_cclk_cycles(struct xilinx_spi_conf *conf)
+{
+ struct spi_device *spi = conf->spi;
+ const u8 din_data[1] = { 0xff };
+ int ret;
+
+ ret = spi_write(conf->spi, din_data, sizeof(din_data));
+ if (ret)
+ dev_err(&spi->dev, "applying CCLK cycles failed: %d\n", ret);
+
+ return ret;
+}
+
+static int xilinx_spi_write_complete(struct fpga_manager *mgr,
+ struct fpga_image_info *info)
+{
+ struct xilinx_spi_conf *conf = mgr->priv;
+ unsigned long timeout;
+ int ret;
+
+ if (gpiod_get_value(conf->done))
+ return xilinx_spi_apply_cclk_cycles(conf);
+
+ timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+
+ while (time_before(jiffies, timeout)) {
+
+ ret = xilinx_spi_apply_cclk_cycles(conf);
+ if (ret)
+ return ret;
+
+ if (gpiod_get_value(conf->done))
+ return xilinx_spi_apply_cclk_cycles(conf);
+ }
+
+ dev_err(&mgr->dev, "Timeout after config data transfer.\n");
+ return -ETIMEDOUT;
+}
+
+static const struct fpga_manager_ops xilinx_spi_ops = {
+ .state = xilinx_spi_state,
+ .write_init = xilinx_spi_write_init,
+ .write = xilinx_spi_write,
+ .write_complete = xilinx_spi_write_complete,
+};
+
+static int xilinx_spi_probe(struct spi_device *spi)
+{
+ struct xilinx_spi_conf *conf;
+
+ conf = devm_kzalloc(&spi->dev, sizeof(*conf), GFP_KERNEL);
+ if (!conf)
+ return -ENOMEM;
+
+ conf->spi = spi;
+
+ /* PROGRAM_B is active low */
+ conf->prog_b = devm_gpiod_get(&spi->dev, "prog_b", GPIOD_OUT_LOW);
+ if (IS_ERR(conf->prog_b)) {
+ dev_err(&spi->dev, "Failed to get PROGRAM_B gpio: %ld\n",
+ PTR_ERR(conf->prog_b));
+ return PTR_ERR(conf->prog_b);
+ }
+
+ conf->done = devm_gpiod_get(&spi->dev, "done", GPIOD_IN);
+ if (IS_ERR(conf->done)) {
+ dev_err(&spi->dev, "Failed to get DONE gpio: %ld\n",
+ PTR_ERR(conf->done));
+ return PTR_ERR(conf->done);
+ }
+
+ return fpga_mgr_register(&spi->dev, "Xilinx Slave Serial FPGA Manager",
+ &xilinx_spi_ops, conf);
+}
+
+static int xilinx_spi_remove(struct spi_device *spi)
+{
+ fpga_mgr_unregister(&spi->dev);
+
+ return 0;
+}
+
+static const struct of_device_id xlnx_spi_of_match[] = {
+ { .compatible = "xlnx,fpga-slave-serial", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, xlnx_spi_of_match);
+
+static struct spi_driver xilinx_slave_spi_driver = {
+ .driver = {
+ .name = "xlnx-slave-spi",
+ .of_match_table = of_match_ptr(xlnx_spi_of_match),
+ },
+ .probe = xilinx_spi_probe,
+ .remove = xilinx_spi_remove,
+};
+
+module_spi_driver(xilinx_slave_spi_driver)
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Anatolij Gustschin <agust@denx.de>");
+MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SPI");

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