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authorAlessandro Rubini <rubini@gnudd.com>2013-06-18 23:47:56 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-06-18 15:42:15 -0700
commit6007b1bd0f752a5c022f7944c65fb96c39d6db3d (patch)
treed0b3074fc8e0589603dbbe4ebc8a3b5c52287842 /drivers/fmc/fmc-write-eeprom.c
parent056d83f3c30c398f14eb879f1d1707e3a7808f4a (diff)
downloadop-kernel-dev-6007b1bd0f752a5c022f7944c65fb96c39d6db3d.zip
op-kernel-dev-6007b1bd0f752a5c022f7944c65fb96c39d6db3d.tar.gz
FMC: add a driver to write mezzanine EEPROM
This driver allows to reprogram the EEPROM in a mezzanine, to store its own identifiers during manufacturing or to save other useful data. Signed-off-by: Alessandro Rubini <rubini@gnudd.com> Acked-by: Juan David Gonzalez Cobas <dcobas@cern.ch> Acked-by: Emilio G. Cota <cota@braap.org> Acked-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/fmc/fmc-write-eeprom.c')
-rw-r--r--drivers/fmc/fmc-write-eeprom.c176
1 files changed, 176 insertions, 0 deletions
diff --git a/drivers/fmc/fmc-write-eeprom.c b/drivers/fmc/fmc-write-eeprom.c
new file mode 100644
index 0000000..2cc680d
--- /dev/null
+++ b/drivers/fmc/fmc-write-eeprom.c
@@ -0,0 +1,176 @@
+/*
+ * Copyright (C) 2012 CERN (www.cern.ch)
+ * Author: Alessandro Rubini <rubini@gnudd.com>
+ *
+ * Released according to the GNU GPL, version 2 or any later version.
+ *
+ * This work is part of the White Rabbit project, a research effort led
+ * by CERN, the European Institute for Nuclear Research.
+ */
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/firmware.h>
+#include <linux/init.h>
+#include <linux/fmc.h>
+#include <asm/unaligned.h>
+
+/*
+ * This module uses the firmware loader to program the whole or part
+ * of the FMC eeprom. The meat is in the _run functions. However, no
+ * default file name is provided, to avoid accidental mishaps. Also,
+ * you must pass the busid argument
+ */
+static struct fmc_driver fwe_drv;
+
+FMC_PARAM_BUSID(fwe_drv);
+
+/* The "file=" is like the generic "gateware=" used elsewhere */
+static char *fwe_file[FMC_MAX_CARDS];
+static int fwe_file_n;
+module_param_array_named(file, fwe_file, charp, &fwe_file_n, 444);
+
+static int fwe_run_tlv(struct fmc_device *fmc, const struct firmware *fw,
+ int write)
+{
+ const uint8_t *p = fw->data;
+ int len = fw->size;
+ uint16_t thislen, thisaddr;
+ int err;
+
+ /* format is: 'w' addr16 len16 data... */
+ while (len > 5) {
+ thisaddr = get_unaligned_le16(p+1);
+ thislen = get_unaligned_le16(p+3);
+ if (p[0] != 'w' || thislen + 5 > len) {
+ dev_err(&fmc->dev, "invalid tlv at offset %ti\n",
+ p - fw->data);
+ return -EINVAL;
+ }
+ err = 0;
+ if (write) {
+ dev_info(&fmc->dev, "write %i bytes at 0x%04x\n",
+ thislen, thisaddr);
+ err = fmc->op->write_ee(fmc, thisaddr, p + 5, thislen);
+ }
+ if (err < 0) {
+ dev_err(&fmc->dev, "write failure @0x%04x\n",
+ thisaddr);
+ return err;
+ }
+ p += 5 + thislen;
+ len -= 5 + thislen;
+ }
+ if (write)
+ dev_info(&fmc->dev, "write_eeprom: success\n");
+ return 0;
+}
+
+static int fwe_run_bin(struct fmc_device *fmc, const struct firmware *fw)
+{
+ int ret;
+
+ dev_info(&fmc->dev, "programming %zi bytes\n", fw->size);
+ ret = fmc->op->write_ee(fmc, 0, (void *)fw->data, fw->size);
+ if (ret < 0) {
+ dev_info(&fmc->dev, "write_eeprom: error %i\n", ret);
+ return ret;
+ }
+ dev_info(&fmc->dev, "write_eeprom: success\n");
+ return 0;
+}
+
+static int fwe_run(struct fmc_device *fmc, const struct firmware *fw, char *s)
+{
+ char *last4 = s + strlen(s) - 4;
+ int err;
+
+ if (!strcmp(last4, ".bin"))
+ return fwe_run_bin(fmc, fw);
+ if (!strcmp(last4, ".tlv")) {
+ err = fwe_run_tlv(fmc, fw, 0);
+ if (!err)
+ err = fwe_run_tlv(fmc, fw, 1);
+ return err;
+ }
+ dev_err(&fmc->dev, "invalid file name \"%s\"\n", s);
+ return -EINVAL;
+}
+
+/*
+ * Programming is done at probe time. Morever, only those listed with
+ * busid= are programmed.
+ * card is probed for, only one is programmed. Unfortunately, it's
+ * difficult to know in advance when probing the first card if others
+ * are there.
+ */
+int fwe_probe(struct fmc_device *fmc)
+{
+ int err, index = 0;
+ const struct firmware *fw;
+ struct device *dev = &fmc->dev;
+ char *s;
+
+ if (!fwe_drv.busid_n) {
+ dev_err(dev, "%s: no busid passed, refusing all cards\n",
+ KBUILD_MODNAME);
+ return -ENODEV;
+ }
+ if (fmc->op->validate)
+ index = fmc->op->validate(fmc, &fwe_drv);
+ if (index < 0) {
+ pr_err("%s: refusing device \"%s\"\n", KBUILD_MODNAME,
+ dev_name(dev));
+ return -ENODEV;
+ }
+ if (index >= fwe_file_n) {
+ pr_err("%s: no filename for device index %i\n",
+ KBUILD_MODNAME, index);
+ return -ENODEV;
+ }
+ s = fwe_file[index];
+ if (!s) {
+ pr_err("%s: no filename for \"%s\" not programming\n",
+ KBUILD_MODNAME, dev_name(dev));
+ return -ENOENT;
+ }
+ err = request_firmware(&fw, s, dev);
+ if (err < 0) {
+ dev_err(&fmc->dev, "request firmware \"%s\": error %i\n",
+ s, err);
+ return err;
+ }
+ fwe_run(fmc, fw, s);
+ release_firmware(fw);
+ return 0;
+}
+
+int fwe_remove(struct fmc_device *fmc)
+{
+ return 0;
+}
+
+static struct fmc_driver fwe_drv = {
+ .version = FMC_VERSION,
+ .driver.name = KBUILD_MODNAME,
+ .probe = fwe_probe,
+ .remove = fwe_remove,
+ /* no table, as the current match just matches everything */
+};
+
+static int fwe_init(void)
+{
+ int ret;
+
+ ret = fmc_driver_register(&fwe_drv);
+ return ret;
+}
+
+static void fwe_exit(void)
+{
+ fmc_driver_unregister(&fwe_drv);
+}
+
+module_init(fwe_init);
+module_exit(fwe_exit);
+
+MODULE_LICENSE("GPL");
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