This patch adds support to the FPGA manager for programming
MachXO2 device’s internal flash memory, via slave SPI.
Signed-off-by: Paolo Pisati <p.pisati@xxxxxxxxx>
---
drivers/fpga/Kconfig | 7 ++
drivers/fpga/Makefile | 1 +
drivers/fpga/machxo2-spi.c | 214 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 222 insertions(+)
create mode 100644 drivers/fpga/machxo2-spi.c
diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index c81cb7d..cce135b 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -26,6 +26,13 @@ config FPGA_MGR_ICE40_SPI
help
FPGA manager driver support for Lattice iCE40 FPGAs over SPI.
+config FPGA_MGR_MACHXO2_SPI
+ tristate "Lattice MachXO2 SPI"
+ depends on SPI
+ help
+ FPGA manager driver support for Lattice MachXO2 configuration
+ over slave SPI interface.
+
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 c6f5d74..cdab1fe 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_FPGA) += fpga-mgr.o
# FPGA Manager Drivers
obj-$(CONFIG_FPGA_MGR_ICE40_SPI) += ice40-spi.o
+obj-$(CONFIG_FPGA_MGR_MACHXO2_SPI) += machxo2-spi.o
obj-$(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/machxo2-spi.c b/drivers/fpga/machxo2-spi.c
new file mode 100644
index 0000000..264ef63
--- /dev/null
+++ b/drivers/fpga/machxo2-spi.c
@@ -0,0 +1,214 @@
+/**
+ * Lattice MachXO2 Slave SPI Driver
+ *
+ * Copyright (C) 2017 Paolo Pisati <p.pisati@xxxxxxxxx>
+ *
+ * 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 Lattice FPGA firmware that is loaded over SPI using
+ * the slave serial configuration interface.
+ */
+
+#include <linux/delay.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/spi/spi.h>
+
+/* MachXO2 Programming Guide - sysCONFIG Programming Commands */
+
+#define ISC_ENABLE 0x000008c6
+#define ISC_ERASE 0x0000040e
+#define ISC_PROGRAMDONE 0x0000005e
+#define LSC_CHECKBUSY 0x000000f0
+#define LSC_INITADDRESS 0x00000046
+#define LSC_PROGINCRNV 0x01000070
+#define LSC_REFRESH 0x00000079
+
+#define BUSYFLAG 0x80
+
+/*
+ * Max CCLK in Slave SPI mode according to 'MachXO2 Family Data
+ * Sheet' sysCONFIG Port Timing Specifications (3-36)
+ */
+#define MACHXO2_MAX_SPEED 66000000
+
+#define MACHXO2_LOW_DELAY 5 /* us */
+#define MACHXO2_HIGH_DELAY 200 /* us */
+
+#define MACHXO2_OP_SIZE sizeof(u32)
+#define MACHXO2_PAGE_SIZE 16
+#define MACHXO2_BUF_SIZE (MACHXO2_OP_SIZE + MACHXO2_PAGE_SIZE)
+
+static int wait_until_not_busy(struct spi_device *spi)
+{
+ u8 rx;
+ u32 checkbusy = LSC_CHECKBUSY;
+ int ret;
+
+ do {
+ ret = spi_write_then_read(spi, &checkbusy, MACHXO2_OP_SIZE,
+ &rx, sizeof(rx));
+ if (ret)
+ return ret;
+ } while (rx & BUSYFLAG);
+
+ return 0;
+}
+
+static enum fpga_mgr_states machxo2_spi_state(struct fpga_manager *mgr)
+{
+ return FPGA_MGR_STATE_UNKNOWN;
+}
+
+static int machxo2_write_init(struct fpga_manager *mgr,
+ struct fpga_image_info *info,
+ const char *buf, size_t count)
+{
+ struct spi_device *spi = mgr->priv;
+ u32 enable = ISC_ENABLE;
+ u32 erase = ISC_ERASE;
+ u32 initaddr = LSC_INITADDRESS;
+ int ret;
+
+ if ((info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
+ dev_err(&mgr->dev,
+ "Partial reconfiguration is not supported\n");
+ return -ENOTSUPP;
+ }
+
+ ret = spi_write(spi, &enable, MACHXO2_OP_SIZE);
+ if (ret)
+ goto fail;
+
+ udelay(MACHXO2_LOW_DELAY);
+ ret = spi_write(spi, &erase, MACHXO2_OP_SIZE);
+ if (ret)
+ goto fail;
+
+ ret = wait_until_not_busy(spi);
+ if (ret)
+ goto fail;
+
+ ret = spi_write(spi, &initaddr, MACHXO2_OP_SIZE);
+ if (ret)
+ goto fail;
+
+ return 0;
+
+fail:
+ dev_err(&mgr->dev, "Error during FPGA init.\n");
+ return ret;
+}
+
+static int machxo2_write(struct fpga_manager *mgr, const char *buf,
+ size_t count)
+{
+ struct spi_device *spi = mgr->priv;
+ u32 progincr = LSC_PROGINCRNV;
+ u8 payload[MACHXO2_BUF_SIZE];
+ int i, ret;
+
+ if (count % MACHXO2_PAGE_SIZE != 0) {
+ dev_err(&mgr->dev, "Malformed payload.\n");
+ return -EINVAL;
+ }
+
+ memcpy(payload, &progincr, MACHXO2_OP_SIZE);
+ for (i = 0; i < count; i += MACHXO2_PAGE_SIZE) {
+ memcpy(&payload[MACHXO2_OP_SIZE], &buf[i], MACHXO2_PAGE_SIZE);
+ ret = spi_write(spi, payload, MACHXO2_BUF_SIZE);
+ if (ret) {
+ dev_err(&mgr->dev, "Error loading the bitstream.\n");
+ return ret;
+ }
+ udelay(MACHXO2_HIGH_DELAY);
+ }
+
+ return 0;
+}
+
+static int machxo2_write_complete(struct fpga_manager *mgr,
+ struct fpga_image_info *info)
+{
+ struct spi_device *spi = mgr->priv;
+ u32 progdone = ISC_PROGRAMDONE;
+ u32 refresh = LSC_REFRESH;
+ int ret;
+
+ ret = spi_write(spi, &progdone, MACHXO2_OP_SIZE);
+ if (ret)
+ goto fail;
+
+ udelay(MACHXO2_HIGH_DELAY);
+ /* yep, LSC_REFRESH is 3 bytes long actually */
+ ret = spi_write(spi, &refresh, MACHXO2_OP_SIZE - 1);
+ if (ret)
+ goto fail;
+
+ return 0;
+
+fail:
+ dev_err(&mgr->dev, "Refresh failed.\n");
+ return ret;
+}
+
+static const struct fpga_manager_ops machxo2_ops = {
+ .state = machxo2_spi_state,
+ .write_init = machxo2_write_init,
+ .write = machxo2_write,
+ .write_complete = machxo2_write_complete,
+};
+
+static int machxo2_spi_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+
+ if (spi->max_speed_hz > MACHXO2_MAX_SPEED) {
+ dev_err(dev, "Speed is too high\n");
+ return -EINVAL;
+ }
+
+ return fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
+ &machxo2_ops, spi);
+}
+
+static int machxo2_spi_remove(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+
+ fpga_mgr_unregister(dev);
+
+ return 0;
+}
+
+static const struct of_device_id of_match[] = {
+ { .compatible = "lattice,machxo2-slave-spi", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, of_match);
+
+static const struct spi_device_id lattice_ids[] = {
+ { "machxo2-slave-spi", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(spi, lattice_ids);
+
+static struct spi_driver machxo2_spi_driver = {
+ .driver = {
+ .name = "machxo2-slave-spi",
+ .of_match_table = of_match_ptr(of_match),
+ },
+ .probe = machxo2_spi_probe,
+ .remove = machxo2_spi_remove,
+ .id_table = lattice_ids,
+};
+
+module_spi_driver(machxo2_spi_driver)
+
+MODULE_AUTHOR("Paolo Pisati <p.pisati@xxxxxxxxx>");
+MODULE_DESCRIPTION("Load Lattice FPGA firmware over SPI");
+MODULE_LICENSE("GPL v2");
--
2.7.4
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