summaryrefslogtreecommitdiff
path: root/drivers/fpga/ts73xx-fpga.c
blob: 101f016c6ed8c8997d3cc0f35388a9ae00bf8d92 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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.
 */

#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))
		return PTR_ERR(priv->io_base);

	mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
				   &ts73xx_fpga_ops, priv);
	if (!mgr)
		return -ENOMEM;

	return devm_fpga_mgr_register(kdev, mgr);
}

static struct platform_driver ts73xx_fpga_driver = {
	.driver	= {
		.name	= "ts73xx-fpga-mgr",
	},
	.probe	= ts73xx_fpga_probe,
};
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");