1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Technologic Systems TS-73xx SBC FPGA loader
  4 *
  5 * Copyright (C) 2016 Florian Fainelli <f.fainelli@gmail.com>
  6 *
  7 * FPGA Manager Driver for the on-board Altera Cyclone II FPGA found on
  8 * TS-7300, heavily based on load_fpga.c in their vendor tree.
  9 */
 10
 11#include <linux/delay.h>
 12#include <linux/io.h>
 13#include <linux/module.h>
 14#include <linux/platform_device.h>
 15#include <linux/string.h>
 16#include <linux/iopoll.h>
 17#include <linux/fpga/fpga-mgr.h>
 18
 19#define TS73XX_FPGA_DATA_REG		0
 20#define TS73XX_FPGA_CONFIG_REG		1
 21
 22#define TS73XX_FPGA_WRITE_DONE		0x1
 23#define TS73XX_FPGA_WRITE_DONE_TIMEOUT	1000	/* us */
 24#define TS73XX_FPGA_RESET		0x2
 25#define TS73XX_FPGA_RESET_LOW_DELAY	30	/* us */
 26#define TS73XX_FPGA_RESET_HIGH_DELAY	80	/* us */
 27#define TS73XX_FPGA_LOAD_OK		0x4
 28#define TS73XX_FPGA_CONFIG_LOAD		0x8
 29
 30struct ts73xx_fpga_priv {
 31	void __iomem	*io_base;
 32	struct device	*dev;
 33};
 34
 35static enum fpga_mgr_states ts73xx_fpga_state(struct fpga_manager *mgr)
 36{
 37	return FPGA_MGR_STATE_UNKNOWN;
 38}
 39
 40static int ts73xx_fpga_write_init(struct fpga_manager *mgr,
 41				  struct fpga_image_info *info,
 42				  const char *buf, size_t count)
 43{
 44	struct ts73xx_fpga_priv *priv = mgr->priv;
 45
 46	/* Reset the FPGA */
 47	writeb(0, priv->io_base + TS73XX_FPGA_CONFIG_REG);
 48	udelay(TS73XX_FPGA_RESET_LOW_DELAY);
 49	writeb(TS73XX_FPGA_RESET, priv->io_base + TS73XX_FPGA_CONFIG_REG);
 50	udelay(TS73XX_FPGA_RESET_HIGH_DELAY);
 51
 52	return 0;
 53}
 54
 55static int ts73xx_fpga_write(struct fpga_manager *mgr, const char *buf,
 56			     size_t count)
 57{
 58	struct ts73xx_fpga_priv *priv = mgr->priv;
 59	size_t i = 0;
 60	int ret;
 61	u8 reg;
 62
 63	while (count--) {
 64		ret = readb_poll_timeout(priv->io_base + TS73XX_FPGA_CONFIG_REG,
 65					 reg, !(reg & TS73XX_FPGA_WRITE_DONE),
 66					 1, TS73XX_FPGA_WRITE_DONE_TIMEOUT);
 67		if (ret < 0)
 68			return ret;
 69
 70		writeb(buf[i], priv->io_base + TS73XX_FPGA_DATA_REG);
 71		i++;
 72	}
 73
 74	return 0;
 75}
 76
 77static int ts73xx_fpga_write_complete(struct fpga_manager *mgr,
 78				      struct fpga_image_info *info)
 79{
 80	struct ts73xx_fpga_priv *priv = mgr->priv;
 81	u8 reg;
 82
 83	usleep_range(1000, 2000);
 84	reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
 85	reg |= TS73XX_FPGA_CONFIG_LOAD;
 86	writeb(reg, priv->io_base + TS73XX_FPGA_CONFIG_REG);
 87
 88	usleep_range(1000, 2000);
 89	reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
 90	reg &= ~TS73XX_FPGA_CONFIG_LOAD;
 91	writeb(reg, priv->io_base + TS73XX_FPGA_CONFIG_REG);
 92
 93	reg = readb(priv->io_base + TS73XX_FPGA_CONFIG_REG);
 94	if ((reg & TS73XX_FPGA_LOAD_OK) != TS73XX_FPGA_LOAD_OK)
 95		return -ETIMEDOUT;
 96
 97	return 0;
 98}
 99
100static const struct fpga_manager_ops ts73xx_fpga_ops = {
101	.state		= ts73xx_fpga_state,
102	.write_init	= ts73xx_fpga_write_init,
103	.write		= ts73xx_fpga_write,
104	.write_complete	= ts73xx_fpga_write_complete,
105};
106
107static int ts73xx_fpga_probe(struct platform_device *pdev)
108{
109	struct device *kdev = &pdev->dev;
110	struct ts73xx_fpga_priv *priv;
111	struct fpga_manager *mgr;
112	struct resource *res;
113
114	priv = devm_kzalloc(kdev, sizeof(*priv), GFP_KERNEL);
115	if (!priv)
116		return -ENOMEM;
117
118	priv->dev = kdev;
119
120	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
121	priv->io_base = devm_ioremap_resource(kdev, res);
122	if (IS_ERR(priv->io_base))
123		return PTR_ERR(priv->io_base);
124
125	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
126				   &ts73xx_fpga_ops, priv);
127	if (!mgr)
128		return -ENOMEM;
129
130	return devm_fpga_mgr_register(kdev, mgr);
131}
132
133static struct platform_driver ts73xx_fpga_driver = {
134	.driver	= {
135		.name	= "ts73xx-fpga-mgr",
136	},
137	.probe	= ts73xx_fpga_probe,
138};
139module_platform_driver(ts73xx_fpga_driver);
140
141MODULE_AUTHOR("Florian Fainelli <f.fainelli@gmail.com>");
142MODULE_DESCRIPTION("TS-73xx FPGA Manager driver");
143MODULE_LICENSE("GPL v2");