/*
* FPGA to SDRAM Bridge Driver for Altera SoCFPGA Devices
*
* Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved.
*
* 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.
*
* This program is distributed in the hope 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.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see .
*/
/*
* 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
#include
#include
#include
#include
#include
#include
#include
#define SOCFPGA_SDRCTL_ADDR 0xffc25000
#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
#define SOCFPGA_SYSMGR_ADDR 0xffd08000
/*
* 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_d *dev;
int mask;
};
static inline int _alt_fpga2sdram_enable_set(struct alt_fpga2sdram_data *priv,
bool enable)
{
int val;
val = readl(SOCFPGA_SDRCTL_ADDR + ALT_SDR_CTL_FPGAPORTRST_OFST);
if (enable)
val |= priv->mask;
else
val = 0;
/* The kernel driver expects this value in this register :-( */
writel(priv->mask, SOCFPGA_SYSMGR_ADDR + SYSMGR_ISWGRP_HANDOFF3);
dev_dbg(priv->dev, "setting fpgaportrst to 0x%08x\n", val);
return writel(val, SOCFPGA_SDRCTL_ADDR + ALT_SDR_CTL_FPGAPORTRST_OFST);
}
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,
};
static struct of_device_id altera_fpga_of_match[] = {
{ .compatible = "altr,socfpga-fpga2sdram-bridge" },
{},
};
static int alt_fpga_bridge_probe(struct device_d *dev)
{
struct alt_fpga2sdram_data *priv;
int ret = 0;
priv = xzalloc(sizeof(*priv));
if (!priv)
return -ENOMEM;
/* enable all ports for now */
priv->mask = ALT_SDR_CTL_FPGAPORTRST_PORTRSTN_MSK;
priv->dev = dev;
ret = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
&altera_fpga2sdram_br_ops, priv);
if (ret)
return ret;
dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);
return ret;
}
static struct driver_d altera_fpga_driver = {
.probe = alt_fpga_bridge_probe,
.name = "altera-fpga2sdram-bridge",
.of_compatible = DRV_OF_COMPAT(altera_fpga_of_match),
};
device_platform_driver(altera_fpga_driver);