v4.19.13 snapshot.
diff --git a/drivers/fpga/altera-fpga2sdram.c b/drivers/fpga/altera-fpga2sdram.c
new file mode 100644
index 0000000..23660cc
--- /dev/null
+++ b/drivers/fpga/altera-fpga2sdram.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FPGA to SDRAM Bridge Driver for Altera SoCFPGA Devices
+ *
+ * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
+ */
+
+/*
+ * This driver manages a bridge between an FPGA and the SDRAM used by the ARM
+ * host processor system (HPS).
+ *
+ * The bridge contains 4 read ports, 4 write ports, and 6 command ports.
+ * Reconfiguring these ports requires that no SDRAM transactions occur during
+ * reconfiguration. The code reconfiguring the ports cannot run out of SDRAM
+ * nor can the FPGA access the SDRAM during reconfiguration. This driver does
+ * not support reconfiguring the ports. The ports are configured by code
+ * running out of on chip ram before Linux is started and the configuration
+ * is passed in a handoff register in the system manager.
+ *
+ * This driver supports enabling and disabling of the configured ports, which
+ * allows for safe reprogramming of the FPGA, assuming that the new FPGA image
+ * uses the same port configuration. Bridges must be disabled before
+ * reprogramming the FPGA and re-enabled after the FPGA has been programmed.
+ */
+
+#include <linux/fpga/fpga-bridge.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+
+#define ALT_SDR_CTL_FPGAPORTRST_OFST 0x80
+#define ALT_SDR_CTL_FPGAPORTRST_PORTRSTN_MSK 0x00003fff
+#define ALT_SDR_CTL_FPGAPORTRST_RD_SHIFT 0
+#define ALT_SDR_CTL_FPGAPORTRST_WR_SHIFT 4
+#define ALT_SDR_CTL_FPGAPORTRST_CTRL_SHIFT 8
+
+/*
+ * From the Cyclone V HPS Memory Map document:
+ * These registers are used to store handoff information between the
+ * preloader and the OS. These 8 registers can be used to store any
+ * information. The contents of these registers have no impact on
+ * the state of the HPS hardware.
+ */
+#define SYSMGR_ISWGRP_HANDOFF3 (0x8C)
+
+#define F2S_BRIDGE_NAME "fpga2sdram"
+
+struct alt_fpga2sdram_data {
+ struct device *dev;
+ struct regmap *sdrctl;
+ int mask;
+};
+
+static int alt_fpga2sdram_enable_show(struct fpga_bridge *bridge)
+{
+ struct alt_fpga2sdram_data *priv = bridge->priv;
+ int value;
+
+ regmap_read(priv->sdrctl, ALT_SDR_CTL_FPGAPORTRST_OFST, &value);
+
+ return (value & priv->mask) == priv->mask;
+}
+
+static inline int _alt_fpga2sdram_enable_set(struct alt_fpga2sdram_data *priv,
+ bool enable)
+{
+ return regmap_update_bits(priv->sdrctl, ALT_SDR_CTL_FPGAPORTRST_OFST,
+ priv->mask, enable ? priv->mask : 0);
+}
+
+static int alt_fpga2sdram_enable_set(struct fpga_bridge *bridge, bool enable)
+{
+ return _alt_fpga2sdram_enable_set(bridge->priv, enable);
+}
+
+struct prop_map {
+ char *prop_name;
+ u32 *prop_value;
+ u32 prop_max;
+};
+
+static const struct fpga_bridge_ops altera_fpga2sdram_br_ops = {
+ .enable_set = alt_fpga2sdram_enable_set,
+ .enable_show = alt_fpga2sdram_enable_show,
+};
+
+static const struct of_device_id altera_fpga_of_match[] = {
+ { .compatible = "altr,socfpga-fpga2sdram-bridge" },
+ {},
+};
+
+static int alt_fpga_bridge_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct alt_fpga2sdram_data *priv;
+ struct fpga_bridge *br;
+ u32 enable;
+ struct regmap *sysmgr;
+ int ret = 0;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+
+ priv->sdrctl = syscon_regmap_lookup_by_compatible("altr,sdr-ctl");
+ if (IS_ERR(priv->sdrctl)) {
+ dev_err(dev, "regmap for altr,sdr-ctl lookup failed.\n");
+ return PTR_ERR(priv->sdrctl);
+ }
+
+ sysmgr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
+ if (IS_ERR(sysmgr)) {
+ dev_err(dev, "regmap for altr,sys-mgr lookup failed.\n");
+ return PTR_ERR(sysmgr);
+ }
+
+ /* Get f2s bridge configuration saved in handoff register */
+ regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);
+
+ br = fpga_bridge_create(dev, F2S_BRIDGE_NAME,
+ &altera_fpga2sdram_br_ops, priv);
+ if (!br)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, br);
+
+ ret = fpga_bridge_register(br);
+ if (ret) {
+ fpga_bridge_free(br);
+ return ret;
+ }
+
+ dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
+
+ if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
+ if (enable > 1) {
+ dev_warn(dev, "invalid bridge-enable %u > 1\n", enable);
+ } else {
+ dev_info(dev, "%s bridge\n",
+ (enable ? "enabling" : "disabling"));
+ ret = _alt_fpga2sdram_enable_set(priv, enable);
+ if (ret) {
+ fpga_bridge_unregister(br);
+ return ret;
+ }
+ }
+ }
+
+ return ret;
+}
+
+static int alt_fpga_bridge_remove(struct platform_device *pdev)
+{
+ struct fpga_bridge *br = platform_get_drvdata(pdev);
+
+ fpga_bridge_unregister(br);
+
+ return 0;
+}
+
+MODULE_DEVICE_TABLE(of, altera_fpga_of_match);
+
+static struct platform_driver altera_fpga_driver = {
+ .probe = alt_fpga_bridge_probe,
+ .remove = alt_fpga_bridge_remove,
+ .driver = {
+ .name = "altera_fpga2sdram_bridge",
+ .of_match_table = of_match_ptr(altera_fpga_of_match),
+ },
+};
+
+module_platform_driver(altera_fpga_driver);
+
+MODULE_DESCRIPTION("Altera SoCFPGA FPGA to SDRAM Bridge");
+MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
+MODULE_LICENSE("GPL v2");