1 /*
2  * Copyright (C) 2012 CERN (www.cern.ch)
3  * Author: Alessandro Rubini <rubini@gnudd.com>
4  *
5  * Released according to the GNU GPL, version 2 or any later version.
6  *
7  * This work is part of the White Rabbit project, a research effort led
8  * by CERN, the European Institute for Nuclear Research.
9  */
10 #include <linux/module.h>
11 #include <linux/string.h>
12 #include <linux/firmware.h>
13 #include <linux/init.h>
14 #include <linux/fmc.h>
15 #include <asm/unaligned.h>
16 
17 /*
18  * This module uses the firmware loader to program the whole or part
19  * of the FMC eeprom. The meat is in the _run functions.  However, no
20  * default file name is provided, to avoid accidental mishaps. Also,
21  * you must pass the busid argument
22  */
23 static struct fmc_driver fwe_drv;
24 
25 FMC_PARAM_BUSID(fwe_drv);
26 
27 /* The "file=" is like the generic "gateware=" used elsewhere */
28 static char *fwe_file[FMC_MAX_CARDS];
29 static int fwe_file_n;
30 module_param_array_named(file, fwe_file, charp, &fwe_file_n, 0444);
31 
fwe_run_tlv(struct fmc_device * fmc,const struct firmware * fw,int write)32 static int fwe_run_tlv(struct fmc_device *fmc, const struct firmware *fw,
33 	int write)
34 {
35 	const uint8_t *p = fw->data;
36 	int len = fw->size;
37 	uint16_t thislen, thisaddr;
38 	int err;
39 
40 	/* format is: 'w' addr16 len16 data... */
41 	while (len > 5) {
42 		thisaddr = get_unaligned_le16(p+1);
43 		thislen = get_unaligned_le16(p+3);
44 		if (p[0] != 'w' || thislen + 5 > len) {
45 			dev_err(&fmc->dev, "invalid tlv at offset %ti\n",
46 				p - fw->data);
47 			return -EINVAL;
48 		}
49 		err = 0;
50 		if (write) {
51 			dev_info(&fmc->dev, "write %i bytes at 0x%04x\n",
52 				 thislen, thisaddr);
53 			err = fmc_write_ee(fmc, thisaddr, p + 5, thislen);
54 		}
55 		if (err < 0) {
56 			dev_err(&fmc->dev, "write failure @0x%04x\n",
57 				thisaddr);
58 			return err;
59 		}
60 		p += 5 + thislen;
61 		len -= 5 + thislen;
62 	}
63 	if (write)
64 		dev_info(&fmc->dev, "write_eeprom: success\n");
65 	return 0;
66 }
67 
fwe_run_bin(struct fmc_device * fmc,const struct firmware * fw)68 static int fwe_run_bin(struct fmc_device *fmc, const struct firmware *fw)
69 {
70 	int ret;
71 
72 	dev_info(&fmc->dev, "programming %zi bytes\n", fw->size);
73 	ret = fmc_write_ee(fmc, 0, (void *)fw->data, fw->size);
74 	if (ret < 0) {
75 		dev_info(&fmc->dev, "write_eeprom: error %i\n", ret);
76 		return ret;
77 	}
78 	dev_info(&fmc->dev, "write_eeprom: success\n");
79 	return 0;
80 }
81 
fwe_run(struct fmc_device * fmc,const struct firmware * fw,char * s)82 static int fwe_run(struct fmc_device *fmc, const struct firmware *fw, char *s)
83 {
84 	char *last4 = s + strlen(s) - 4;
85 	int err;
86 
87 	if (!strcmp(last4, ".bin"))
88 		return fwe_run_bin(fmc, fw);
89 	if (!strcmp(last4, ".tlv")) {
90 		err = fwe_run_tlv(fmc, fw, 0);
91 		if (!err)
92 			err = fwe_run_tlv(fmc, fw, 1);
93 		return err;
94 	}
95 	dev_err(&fmc->dev, "invalid file name \"%s\"\n", s);
96 	return -EINVAL;
97 }
98 
99 /*
100  * Programming is done at probe time. Morever, only those listed with
101  * busid= are programmed.
102  * card is probed for, only one is programmed. Unfortunately, it's
103  * difficult to know in advance when probing the first card if others
104  * are there.
105  */
fwe_probe(struct fmc_device * fmc)106 static int fwe_probe(struct fmc_device *fmc)
107 {
108 	int err, index = 0;
109 	const struct firmware *fw;
110 	struct device *dev = &fmc->dev;
111 	char *s;
112 
113 	if (!fwe_drv.busid_n) {
114 		dev_err(dev, "%s: no busid passed, refusing all cards\n",
115 			KBUILD_MODNAME);
116 		return -ENODEV;
117 	}
118 
119 	index = fmc_validate(fmc, &fwe_drv);
120 	if (index < 0) {
121 		pr_err("%s: refusing device \"%s\"\n", KBUILD_MODNAME,
122 		       dev_name(dev));
123 		return -ENODEV;
124 	}
125 	if (index >= fwe_file_n) {
126 		pr_err("%s: no filename for device index %i\n",
127 			KBUILD_MODNAME, index);
128 		return -ENODEV;
129 	}
130 	s = fwe_file[index];
131 	if (!s) {
132 		pr_err("%s: no filename for \"%s\" not programming\n",
133 		       KBUILD_MODNAME, dev_name(dev));
134 		return -ENOENT;
135 	}
136 	err = request_firmware(&fw, s, dev);
137 	if (err < 0) {
138 		dev_err(&fmc->dev, "request firmware \"%s\": error %i\n",
139 			s, err);
140 		return err;
141 	}
142 	fwe_run(fmc, fw, s);
143 	release_firmware(fw);
144 	return 0;
145 }
146 
fwe_remove(struct fmc_device * fmc)147 static int fwe_remove(struct fmc_device *fmc)
148 {
149 	return 0;
150 }
151 
152 static struct fmc_driver fwe_drv = {
153 	.version = FMC_VERSION,
154 	.driver.name = KBUILD_MODNAME,
155 	.probe = fwe_probe,
156 	.remove = fwe_remove,
157 	/* no table, as the current match just matches everything */
158 };
159 
fwe_init(void)160 static int fwe_init(void)
161 {
162 	int ret;
163 
164 	ret = fmc_driver_register(&fwe_drv);
165 	return ret;
166 }
167 
fwe_exit(void)168 static void fwe_exit(void)
169 {
170 	fmc_driver_unregister(&fwe_drv);
171 }
172 
173 module_init(fwe_init);
174 module_exit(fwe_exit);
175 
176 MODULE_LICENSE("GPL");
177