1 // SPDX-License-Identifier: GPL-2.0
3  * FPGA to SDRAM Bridge Driver for Altera SoCFPGA Devices
5  *  Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
9  * This driver manages a bridge between an FPGA and the SDRAM used by the ARM
12  * The bridge contains 4 read ports, 4 write ports, and 6 command ports.
23  * reprogramming the FPGA and re-enabled after the FPGA has been programmed.
26 #include <linux/fpga/fpga-bridge.h>
56 static int alt_fpga2sdram_enable_show(struct fpga_bridge *bridge)  in alt_fpga2sdram_enable_show()  argument
58 	struct alt_fpga2sdram_data *priv = bridge->priv;  in alt_fpga2sdram_enable_show()
61 	regmap_read(priv->sdrctl, ALT_SDR_CTL_FPGAPORTRST_OFST, &value);  in alt_fpga2sdram_enable_show()
63 	return (value & priv->mask) == priv->mask;  in alt_fpga2sdram_enable_show()
67 					     bool enable)  in _alt_fpga2sdram_enable_set()  argument
69 	return regmap_update_bits(priv->sdrctl, ALT_SDR_CTL_FPGAPORTRST_OFST,  in _alt_fpga2sdram_enable_set()
70 				  priv->mask, enable ? priv->mask : 0);  in _alt_fpga2sdram_enable_set()
73 static int alt_fpga2sdram_enable_set(struct fpga_bridge *bridge, bool enable)  in alt_fpga2sdram_enable_set()  argument
75 	return _alt_fpga2sdram_enable_set(bridge->priv, enable);  in alt_fpga2sdram_enable_set()
84 	{ .compatible = "altr,socfpga-fpga2sdram-bridge" },
90 	struct device *dev = &pdev->dev;  in alt_fpga_bridge_probe()
93 	u32 enable;  in alt_fpga_bridge_probe()  local
99 		return -ENOMEM;  in alt_fpga_bridge_probe()
101 	priv->dev = dev;  in alt_fpga_bridge_probe()
103 	priv->sdrctl = syscon_regmap_lookup_by_compatible("altr,sdr-ctl");  in alt_fpga_bridge_probe()
104 	if (IS_ERR(priv->sdrctl)) {  in alt_fpga_bridge_probe()
105 		dev_err(dev, "regmap for altr,sdr-ctl lookup failed.\n");  in alt_fpga_bridge_probe()
106 		return PTR_ERR(priv->sdrctl);  in alt_fpga_bridge_probe()
109 	sysmgr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");  in alt_fpga_bridge_probe()
111 		dev_err(dev, "regmap for altr,sys-mgr lookup failed.\n");  in alt_fpga_bridge_probe()
115 	/* Get f2s bridge configuration saved in handoff register */  in alt_fpga_bridge_probe()
116 	regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);  in alt_fpga_bridge_probe()
125 	dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);  in alt_fpga_bridge_probe()
127 	if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {  in alt_fpga_bridge_probe()
128 		if (enable > 1) {  in alt_fpga_bridge_probe()
129 			dev_warn(dev, "invalid bridge-enable %u > 1\n", enable);  in alt_fpga_bridge_probe()
131 			dev_info(dev, "%s bridge\n",  in alt_fpga_bridge_probe()
132 				 (enable ? "enabling" : "disabling"));  in alt_fpga_bridge_probe()
133 			ret = _alt_fpga2sdram_enable_set(priv, enable);  in alt_fpga_bridge_probe()
164 MODULE_DESCRIPTION("Altera SoCFPGA FPGA to SDRAM Bridge");