Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 232 insertions, 0 deletions

diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
new file mode 100644
index 000000000..a974d3f60
--- /dev/null
+++ b/drivers/fpga/altera-hps2fpga.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FPGA to/from HPS Bridge Driver for Altera SoCFPGA Devices
+ *
+ *  Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
+ *
+ * Includes this patch from the mailing list:
+ *   fpga: altera-hps2fpga: fix HPS2FPGA bridge visibility to L3 masters
+ *   Signed-off-by: Anatolij Gustschin <agust@denx.de>
+ */
+
+/*
+ * This driver manages bridges on a Altera SOCFPGA between the ARM host
+ * processor system (HPS) and the embedded FPGA.
+ *
+ * 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/clk.h>
+#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>
+#include <linux/reset.h>
+#include <linux/spinlock.h>
+
+#define ALT_L3_REMAP_OFST			0x0
+#define ALT_L3_REMAP_MPUZERO_MSK		0x00000001
+#define ALT_L3_REMAP_H2F_MSK			0x00000008
+#define ALT_L3_REMAP_LWH2F_MSK			0x00000010
+
+#define HPS2FPGA_BRIDGE_NAME			"hps2fpga"
+#define LWHPS2FPGA_BRIDGE_NAME			"lwhps2fpga"
+#define FPGA2HPS_BRIDGE_NAME			"fpga2hps"
+
+struct altera_hps2fpga_data {
+	const char *name;
+	struct reset_control *bridge_reset;
+	struct regmap *l3reg;
+	unsigned int remap_mask;
+	struct clk *clk;
+};
+
+static int alt_hps2fpga_enable_show(struct fpga_bridge *bridge)
+{
+	struct altera_hps2fpga_data *priv = bridge->priv;
+
+	return reset_control_status(priv->bridge_reset);
+}
+
+/* The L3 REMAP register is write only, so keep a cached value. */
+static unsigned int l3_remap_shadow;
+static DEFINE_SPINLOCK(l3_remap_lock);
+
+static int _alt_hps2fpga_enable_set(struct altera_hps2fpga_data *priv,
+				    bool enable)
+{
+	unsigned long flags;
+	int ret;
+
+	/* bring bridge out of reset */
+	if (enable)
+		ret = reset_control_deassert(priv->bridge_reset);
+	else
+		ret = reset_control_assert(priv->bridge_reset);
+	if (ret)
+		return ret;
+
+	/* Allow bridge to be visible to L3 masters or not */
+	if (priv->remap_mask) {
+		spin_lock_irqsave(&l3_remap_lock, flags);
+		l3_remap_shadow |= ALT_L3_REMAP_MPUZERO_MSK;
+
+		if (enable)
+			l3_remap_shadow |= priv->remap_mask;
+		else
+			l3_remap_shadow &= ~priv->remap_mask;
+
+		ret = regmap_write(priv->l3reg, ALT_L3_REMAP_OFST,
+				   l3_remap_shadow);
+		spin_unlock_irqrestore(&l3_remap_lock, flags);
+	}
+
+	return ret;
+}
+
+static int alt_hps2fpga_enable_set(struct fpga_bridge *bridge, bool enable)
+{
+	return _alt_hps2fpga_enable_set(bridge->priv, enable);
+}
+
+static const struct fpga_bridge_ops altera_hps2fpga_br_ops = {
+	.enable_set = alt_hps2fpga_enable_set,
+	.enable_show = alt_hps2fpga_enable_show,
+};
+
+static struct altera_hps2fpga_data hps2fpga_data  = {
+	.name = HPS2FPGA_BRIDGE_NAME,
+	.remap_mask = ALT_L3_REMAP_H2F_MSK,
+};
+
+static struct altera_hps2fpga_data lwhps2fpga_data  = {
+	.name = LWHPS2FPGA_BRIDGE_NAME,
+	.remap_mask = ALT_L3_REMAP_LWH2F_MSK,
+};
+
+static struct altera_hps2fpga_data fpga2hps_data  = {
+	.name = FPGA2HPS_BRIDGE_NAME,
+};
+
+static const struct of_device_id altera_fpga_of_match[] = {
+	{ .compatible = "altr,socfpga-hps2fpga-bridge",
+	  .data = &hps2fpga_data },
+	{ .compatible = "altr,socfpga-lwhps2fpga-bridge",
+	  .data = &lwhps2fpga_data },
+	{ .compatible = "altr,socfpga-fpga2hps-bridge",
+	  .data = &fpga2hps_data },
+	{},
+};
+
+static int alt_fpga_bridge_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct altera_hps2fpga_data *priv;
+	const struct of_device_id *of_id;
+	struct fpga_bridge *br;
+	u32 enable;
+	int ret;
+
+	of_id = of_match_device(altera_fpga_of_match, dev);
+	if (!of_id) {
+		dev_err(dev, "failed to match device\n");
+		return -ENODEV;
+	}
+
+	priv = (struct altera_hps2fpga_data *)of_id->data;
+
+	priv->bridge_reset = of_reset_control_get_exclusive_by_index(dev->of_node,
+								     0);
+	if (IS_ERR(priv->bridge_reset)) {
+		dev_err(dev, "Could not get %s reset control\n", priv->name);
+		return PTR_ERR(priv->bridge_reset);
+	}
+
+	if (priv->remap_mask) {
+		priv->l3reg = syscon_regmap_lookup_by_compatible("altr,l3regs");
+		if (IS_ERR(priv->l3reg)) {
+			dev_err(dev, "regmap for altr,l3regs lookup failed\n");
+			return PTR_ERR(priv->l3reg);
+		}
+	}
+
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "no clock specified\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret) {
+		dev_err(dev, "could not enable clock\n");
+		return -EBUSY;
+	}
+
+	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_hps2fpga_enable_set(priv, enable);
+			if (ret)
+				goto err;
+		}
+	}
+
+	br = fpga_bridge_create(dev, priv->name, &altera_hps2fpga_br_ops, priv);
+	if (!br) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, br);
+
+	ret = fpga_bridge_register(br);
+	if (ret)
+		goto err_free;
+
+	return 0;
+
+err_free:
+	fpga_bridge_free(br);
+err:
+	clk_disable_unprepare(priv->clk);
+
+	return ret;
+}
+
+static int alt_fpga_bridge_remove(struct platform_device *pdev)
+{
+	struct fpga_bridge *bridge = platform_get_drvdata(pdev);
+	struct altera_hps2fpga_data *priv = bridge->priv;
+
+	fpga_bridge_unregister(bridge);
+
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+MODULE_DEVICE_TABLE(of, altera_fpga_of_match);
+
+static struct platform_driver alt_fpga_bridge_driver = {
+	.probe = alt_fpga_bridge_probe,
+	.remove = alt_fpga_bridge_remove,
+	.driver = {
+		.name	= "altera_hps2fpga_bridge",
+		.of_match_table = of_match_ptr(altera_fpga_of_match),
+	},
+};
+
+module_platform_driver(alt_fpga_bridge_driver);
+
+MODULE_DESCRIPTION("Altera SoCFPGA HPS to FPGA Bridge");
+MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>");
+MODULE_LICENSE("GPL v2");