drivers/fmc/fmc-write-eeprom.c

   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
  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->op->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
  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->op->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
  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  */
 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         if (fmc->op->validate)
 119                 index = fmc->op->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
 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
 160 static int fwe_init(void)
 161 {
 162         int ret;
 163
 164         ret = fmc_driver_register(&fwe_drv);
 165         return ret;
 166 }
 167
 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");