[PATCH v2 2/2] FPGA: Add TS-7300 FPGA manager

From: Florian Fainelli
Date: Tue Dec 13 2016 - 21:29:01 EST


Add support for loading bitstreams on the Altera Cyclone II FPGA
populated on the TS-7300 board. This is done through the configuration
and data registers offered through a memory interface between the EP93xx
SoC and the FPGA via an intermediate CPLD device.

The EP93xx SoC on the TS-7300 does not have direct means of configuring
the on-board FPGA other than by using the special memory mapped
interface to the CPLD. No other entity on the system can control the
FPGA bitstream.

Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
drivers/fpga/Kconfig | 7 ++
drivers/fpga/Makefile | 1 +
drivers/fpga/ts73xx-fpga.c | 162 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 170 insertions(+)
create mode 100644 drivers/fpga/ts73xx-fpga.c

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index ce861a2853a4..d9cbef60db80 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -33,6 +33,13 @@ config FPGA_MGR_SOCFPGA_A10
help
FPGA manager driver support for Altera Arria10 SoCFPGA.

+config FPGA_MGR_TS73XX
+ tristate "Technologic Systems TS-73xx SBC FPGA Manager"
+ depends on ARCH_EP93XX && MACH_TS72XX
+ help
+ FPGA manager driver support for the Altera Cyclone II FPGA
+ present on the TS-73xx SBC boards.
+
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 8df07bcf42a6..a1160169e6d9 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_FPGA) += fpga-mgr.o
# FPGA Manager Drivers
obj-$(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_ZYNQ_FPGA) += zynq-fpga.o

# FPGA Bridge Drivers
diff --git a/drivers/fpga/ts73xx-fpga.c b/drivers/fpga/ts73xx-fpga.c
new file mode 100644
index 000000000000..c004be5954ae
--- /dev/null
+++ b/drivers/fpga/ts73xx-fpga.c
@@ -0,0 +1,162 @@
+/*
+ * Technologic Systems TS-73xx SBC FPGA loader
+ *
+ * Copyright (C) 2016 Florian Fainelli <f.fainelli@xxxxxxxxx>
+ *
+ * FPGA Manager Driver for the on-board Altera Cyclone II FPGA found on
+ * TS-7300, heavily based on load_fpga.c in their vendor tree.
+ *
+ * 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 program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+#include <linux/iopoll.h>
+#include <linux/fpga/fpga-mgr.h>
+
+#define TS73XX_FPGA_DATA_REG 0
+#define TS73XX_FPGA_CONFIG_REG 1
+
+#define TS73XX_FPGA_WRITE_DONE 0x1
+#define TS73XX_FPGA_WRITE_DONE_TIMEOUT 1000 /* us */
+#define TS73XX_FPGA_RESET 0x2
+#define TS73XX_FPGA_RESET_LOW_DELAY 30 /* us */
+#define TS73XX_FPGA_RESET_HIGH_DELAY 80 /* us */
+#define TS73XX_FPGA_LOAD_OK 0x4
+#define TS73XX_FPGA_CONFIG_LOAD 0x8
+
+struct ts73xx_fpga_priv {
+ void __iomem *io_base;
+ struct device *dev;
+};
+
+static enum fpga_mgr_states ts73xx_fpga_state(struct fpga_manager *mgr)
+{
+ return FPGA_MGR_STATE_UNKNOWN;
+}
+
+static int ts73xx_fpga_write_init(struct fpga_manager *mgr, u32 flags,
+ const char *buf, size_t count)
+{
+ struct ts73xx_fpga_priv *priv = mgr->priv;
+
+ /* Reset the FPGA */
+ writeb(0, priv->io_base + TS73XX_FPGA_CONFIG_REG);
+ udelay(TS73XX_FPGA_RESET_LOW_DELAY);
+ writeb(TS73XX_FPGA_RESET, priv->io_base + TS73XX_FPGA_CONFIG_REG);
+ udelay(TS73XX_FPGA_RESET_HIGH_DELAY);
+
+ return 0;
+}
+
+static int ts73xx_fpga_write(struct fpga_manager *mgr, const char *buf,
+ size_t count)
+{
+ struct ts73xx_fpga_priv *priv = mgr->priv;
+ size_t i = 0;
+ int ret;
+ u8 reg;
+
+ while (count--) {
+ ret = readb_poll_timeout(priv->io_base + TS73XX_FPGA_CONFIG_REG,
+ reg, !(reg & TS73XX_FPGA_WRITE_DONE),
+ 1, TS73XX_FPGA_WRITE_DONE_TIMEOUT);
+ if (ret < 0)
+ return ret;
+
+ writeb(buf[i], priv->io_base + TS73XX_FPGA_DATA_REG);
+ i++;
+ }
+
+ usleep_range(1000, 2000);
+ reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
+ reg |= TS73XX_FPGA_CONFIG_LOAD;
+ writeb(reg, priv->io_base + TS73XX_FPGA_CONFIG_REG);
+ usleep_range(1000, 2000);
+
+ reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
+ reg &= ~TS73XX_FPGA_CONFIG_LOAD;
+ writeb(reg, priv->io_base + TS73XX_FPGA_CONFIG_REG);
+
+ return 0;
+}
+
+static int ts73xx_fpga_write_complete(struct fpga_manager *mgr, u32 flags)
+{
+ struct ts73xx_fpga_priv *priv = mgr->priv;
+ u8 reg;
+
+ reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
+ if ((reg & TS73XX_FPGA_LOAD_OK) != TS73XX_FPGA_LOAD_OK)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static const struct fpga_manager_ops ts73xx_fpga_ops = {
+ .state = ts73xx_fpga_state,
+ .write_init = ts73xx_fpga_write_init,
+ .write = ts73xx_fpga_write,
+ .write_complete = ts73xx_fpga_write_complete,
+};
+
+static int ts73xx_fpga_probe(struct platform_device *pdev)
+{
+ struct device *kdev = &pdev->dev;
+ struct ts73xx_fpga_priv *priv;
+ struct fpga_manager *mgr;
+ struct resource *res;
+ int err;
+
+ priv = devm_kzalloc(kdev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = kdev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->io_base = devm_ioremap_resource(kdev, res);
+ if (IS_ERR(priv->io_base)) {
+ dev_err(kdev, "unable to remap registers\n");
+ return PTR_ERR(priv->io_base);
+ }
+
+ err = fpga_mgr_register(kdev, "TS-73xx FPGA Manager",
+ &ts73xx_fpga_ops, priv);
+ if (err) {
+ dev_err(kdev, "failed to register FPGA manager\n");
+ return err;
+ }
+
+ return err;
+}
+
+static int ts73xx_fpga_remove(struct platform_device *pdev)
+{
+ fpga_mgr_unregister(&pdev->dev);
+
+ return 0;
+}
+
+static struct platform_driver ts73xx_fpga_driver = {
+ .driver = {
+ .name = "ts73xx-fpga-mgr",
+ },
+ .probe = ts73xx_fpga_probe,
+ .remove = ts73xx_fpga_remove,
+};
+module_platform_driver(ts73xx_fpga_driver);
+
+MODULE_AUTHOR("Florian Fainelli <f.fainelli@xxxxxxxxx>");
+MODULE_DESCRIPTION("TS-73xx FPGA Manager driver");
+MODULE_LICENSE("GPL v2");
--
2.9.3