linux/drivers/fpga/ts73xx-fpga.c

166 lines
4.3 KiB
C

/*
* Technologic Systems TS-73xx SBC FPGA loader
*
* Copyright (C) 2016 Florian Fainelli <f.fainelli@gmail.com>
*
* 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,
struct fpga_image_info *info,
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++;
}
return 0;
}
static int ts73xx_fpga_write_complete(struct fpga_manager *mgr,
struct fpga_image_info *info)
{
struct ts73xx_fpga_priv *priv = mgr->priv;
u8 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);
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);
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;
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);
}
mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
&ts73xx_fpga_ops, priv);
if (!mgr)
return -ENOMEM;
platform_set_drvdata(pdev, mgr);
return fpga_mgr_register(mgr);
}
static int ts73xx_fpga_remove(struct platform_device *pdev)
{
struct fpga_manager *mgr = platform_get_drvdata(pdev);
fpga_mgr_unregister(mgr);
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@gmail.com>");
MODULE_DESCRIPTION("TS-73xx FPGA Manager driver");
MODULE_LICENSE("GPL v2");