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
30 struct ts73xx_fpga_priv {
31 void __iomem *io_base;
32 struct device *dev;
33 };
34
ts73xx_fpga_state(struct fpga_manager * mgr)35 static enum fpga_mgr_states ts73xx_fpga_state(struct fpga_manager *mgr)
36 {
37 return FPGA_MGR_STATE_UNKNOWN;
38 }
39
ts73xx_fpga_write_init(struct fpga_manager * mgr,struct fpga_image_info * info,const char * buf,size_t count)40 static 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
ts73xx_fpga_write(struct fpga_manager * mgr,const char * buf,size_t count)55 static 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
ts73xx_fpga_write_complete(struct fpga_manager * mgr,struct fpga_image_info * info)77 static 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
100 static 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
ts73xx_fpga_probe(struct platform_device * pdev)107 static 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 dev_err(kdev, "unable to remap registers\n");
124 return PTR_ERR(priv->io_base);
125 }
126
127 mgr = devm_fpga_mgr_create(kdev, "TS-73xx FPGA Manager",
128 &ts73xx_fpga_ops, priv);
129 if (!mgr)
130 return -ENOMEM;
131
132 platform_set_drvdata(pdev, mgr);
133
134 return fpga_mgr_register(mgr);
135 }
136
ts73xx_fpga_remove(struct platform_device * pdev)137 static int ts73xx_fpga_remove(struct platform_device *pdev)
138 {
139 struct fpga_manager *mgr = platform_get_drvdata(pdev);
140
141 fpga_mgr_unregister(mgr);
142
143 return 0;
144 }
145
146 static struct platform_driver ts73xx_fpga_driver = {
147 .driver = {
148 .name = "ts73xx-fpga-mgr",
149 },
150 .probe = ts73xx_fpga_probe,
151 .remove = ts73xx_fpga_remove,
152 };
153 module_platform_driver(ts73xx_fpga_driver);
154
155 MODULE_AUTHOR("Florian Fainelli <f.fainelli@gmail.com>");
156 MODULE_DESCRIPTION("TS-73xx FPGA Manager driver");
157 MODULE_LICENSE("GPL v2");
158
