FMC: add core bus driver

This module offers registration services for both carriers
(i.e. devices) and mezzanines (i.e. drivers). The matching for devices
and drivers is performed according to the IPMI standard for FRU
devices (Field Replaceable Units).

The code includes support for parsing an SDB tree if present in the FPGA,
and dumping it for diagnostics. SDB is not mandatory.

Files in this commit correspond to commit ab23167f in the master branch
of the project hosted on ohwr.org.

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>

1 files changed, 114 insertions, 0 deletions

diff --git a/drivers/fmc/fmc-match.c b/drivers/fmc/fmc-match.c
new file mode 100644
index 000000000000..104a5efc2207
--- /dev/null
+++ b/drivers/fmc/fmc-match.c
@@ -0,0 +1,114 @@
+/*
+ * 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/kernel.h>
+#include <linux/slab.h>
+#include <linux/fmc.h>
+#include <linux/ipmi-fru.h>
+
+/* The fru parser is both user and kernel capable: it needs alloc */
+void *fru_alloc(size_t size)
+{
+	return kzalloc(size, GFP_KERNEL);
+}
+
+/* The actual match function */
+int fmc_match(struct device *dev, struct device_driver *drv)
+{
+	struct fmc_driver *fdrv = to_fmc_driver(drv);
+	struct fmc_device *fdev = to_fmc_device(dev);
+	struct fmc_fru_id *fid;
+	int i, matched = 0;
+
+	/* This currently only matches the EEPROM (FRU id) */
+	fid = fdrv->id_table.fru_id;
+	if (!fid) {
+		dev_warn(&fdev->dev, "Driver has no ID: matches all\n");
+		matched = 1;
+	} else {
+		if (!fdev->id.manufacturer || !fdev->id.product_name)
+			return 0; /* the device has no FRU information */
+		for (i = 0; i < fdrv->id_table.fru_id_nr; i++, fid++) {
+			if (fid->manufacturer &&
+			    strcmp(fid->manufacturer, fdev->id.manufacturer))
+				continue;
+			if (fid->product_name &&
+			    strcmp(fid->product_name, fdev->id.product_name))
+				continue;
+			matched = 1;
+			break;
+		}
+	}
+
+	/* FIXME: match SDB contents */
+	return matched;
+}
+
+/* This function creates ID info for a newly registered device */
+int fmc_fill_id_info(struct fmc_device *fmc)
+{
+	struct fru_common_header *h;
+	struct fru_board_info_area *bia;
+	int ret, allocated = 0;
+
+	/* If we know the eeprom length, try to read it off the device */
+	if (fmc->eeprom_len && !fmc->eeprom) {
+		fmc->eeprom = kzalloc(fmc->eeprom_len, GFP_KERNEL);
+		if (!fmc->eeprom)
+			return -ENOMEM;
+		allocated = 1;
+		ret = fmc->op->read_ee(fmc, 0, fmc->eeprom, fmc->eeprom_len);
+		if (ret < 0)
+			goto out;
+	}
+
+	/* If no eeprom, continue with other matches */
+	if (!fmc->eeprom)
+		return 0;
+
+	dev_info(fmc->hwdev, "mezzanine %i\n", fmc->slot_id); /* header */
+
+	/* So we have the eeprom: parse the FRU part (if any) */
+	h = (void *)fmc->eeprom;
+	if (h->format != 1) {
+		pr_info("      EEPROM has no FRU information\n");
+		goto out;
+	}
+	if (!fru_header_cksum_ok(h)) {
+		pr_info("      FRU: wrong header checksum\n");
+		goto out;
+	}
+	bia = fru_get_board_area(h);
+	if (!fru_bia_cksum_ok(bia)) {
+		pr_info("      FRU: wrong board area checksum\n");
+		goto out;
+	}
+	fmc->id.manufacturer = fru_get_board_manufacturer(h);
+	fmc->id.product_name = fru_get_product_name(h);
+	pr_info("      Manufacturer: %s\n", fmc->id.manufacturer);
+	pr_info("      Product name: %s\n", fmc->id.product_name);
+
+	/* Create the short name (FIXME: look in sdb as well) */
+	fmc->mezzanine_name = kstrdup(fmc->id.product_name, GFP_KERNEL);
+
+out:
+	if (allocated) {
+		kfree(fmc->eeprom);
+		fmc->eeprom = NULL;
+	}
+	return 0; /* no error: let other identification work */
+}
+
+/* Some ID data is allocated using fru_alloc() above, so release it */
+void fmc_free_id_info(struct fmc_device *fmc)
+{
+	kfree(fmc->mezzanine_name);
+	kfree(fmc->id.manufacturer);
+	kfree(fmc->id.product_name);
+}