From: Christopher Bostic <cbostic@linux.vnet.ibm.com>
To: robh+dt@kernel.org, mark.rutland@arm.com, linux@armlinux.org.uk,
gregkh@linuxfoundation.org, mturquette@baylibre.com,
geert+renesas@glider.be, devicetree@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, joel@jms.id.au,
linux-kernel@vger.kernel.org, andrew@aj.id.au,
alistair@popple.id.au, benh@kernel.crashing.org
Cc: Jeremy Kerr <jk@ozlabs.org>, Chris Bostic <cbostic@us.ibm.com>
Subject: [PATCH v3 07/18] drivers/fsi: Add FSI crc calculators to library
Date: Wed, 1 Feb 2017 10:53:47 -0600 [thread overview]
Message-ID: <20170201165358.45415-8-cbostic@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170201165358.45415-1-cbostic@linux.vnet.ibm.com>
From: Jeremy Kerr <jk@ozlabs.org>
Add some helpers for the crc checks for the slave configuration table.
This works 4-bits-at-a-time, using a simple table approach.
We will need this in the FSI core code, as well as any master
implementations that need to calculate CRCs in software.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@us.ibm.com>
---
include/linux/crc-fsi.h | 29 +++++++++++++++++++++++++++++
lib/Makefile | 1 +
lib/crc-fsi.c | 39 +++++++++++++++++++++++++++++++++++++++
3 files changed, 69 insertions(+)
create mode 100644 include/linux/crc-fsi.h
create mode 100644 lib/crc-fsi.c
diff --git a/include/linux/crc-fsi.h b/include/linux/crc-fsi.h
new file mode 100644
index 0000000..e96d2f0
--- /dev/null
+++ b/include/linux/crc-fsi.h
@@ -0,0 +1,29 @@
+/*
+ * FSI CRC calculator
+ *
+ * Copyright (C) IBM Corporation 2016
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ *
+ * Implements the standard FSI CRC:
+ *
+ * Width 1 - 32
+ * Poly 0x0017 (x^4 + x^2 + x^1 + x^0)
+ */
+
+#ifndef CRC_FSI_H
+#define CRC_FSI_H
+
+#include <linux/types.h>
+
+uint8_t crc_fsi(uint8_t c, uint64_t x, int bits);
+
+#endif /* CRC_FSI_H */
diff --git a/lib/Makefile b/lib/Makefile
index 50144a3..c840628 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -230,3 +230,4 @@ obj-$(CONFIG_UBSAN) += ubsan.o
UBSAN_SANITIZE_ubsan.o := n
obj-$(CONFIG_SBITMAP) += sbitmap.o
+obj-$(CONFIG_FSI) += crc-fsi.o
diff --git a/lib/crc-fsi.c b/lib/crc-fsi.c
new file mode 100644
index 0000000..55cfe9d
--- /dev/null
+++ b/lib/crc-fsi.c
@@ -0,0 +1,39 @@
+/*
+ * FSI CRC calculator
+ *
+ * Copyright (C) IBM Corporation 2016
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/crc-fsi.h>
+
+/* crc helpers */
+static const uint8_t crc_fsi_tab[] = {
+ 0x0, 0x7, 0xe, 0x9, 0xb, 0xc, 0x5, 0x2,
+ 0x1, 0x6, 0xf, 0x8, 0xa, 0xd, 0x4, 0x3,
+};
+
+uint8_t crc_fsi(uint8_t c, uint64_t x, int bits)
+{
+ int i;
+
+ /* Align to 4-bits */
+ bits = (bits + 3) & ~0x3;
+
+ /* Calculate crc4 over four-bit nibbles, starting at the MSbit */
+ for (i = bits; i >= 0; i -= 4)
+ c = crc_fsi_tab[c ^ ((x >> i) & 0xf)];
+
+ return c;
+}
+EXPORT_SYMBOL_GPL(crc_fsi);
--
1.8.2.2
next prev parent reply other threads:[~2017-02-01 16:55 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-01 16:53 [PATCH v3 00/18] FSI device driver introduction Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 01/18] drivers/fsi: Add empty fsi bus definitions Christopher Bostic
2017-02-23 10:53 ` Geert Uytterhoeven
2017-02-23 14:24 ` Jeremy Kerr
2017-02-01 16:53 ` [PATCH v3 02/18] drivers/fsi: Add device & driver definitions Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 03/18] drivers/fsi: add driver to device matches Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 04/18] drivers/fsi: Add fsi master definition Christopher Bostic
2017-02-10 14:21 ` Greg KH
2017-02-01 16:53 ` [PATCH v3 05/18] drivers/fsi: Add slave definition Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 06/18] drivers/fsi: Add empty master scan Christopher Bostic
2017-02-01 16:53 ` Christopher Bostic [this message]
2017-02-01 16:53 ` [PATCH v3 08/18] drivers/fsi: Kick off master scan via sysfs Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 09/18] drivers/fsi: Implement slave initialisation Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 10/18] drivers/fsi: scan slaves & register devices Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 11/18] drivers/fsi: Add device read/write/peek functions Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 12/18] drivers/fsi: Set up links for slave communication Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 13/18] drivers/fsi: Set slave SMODE to init communication Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 14/18] drivers/fsi: Remove all scanned devices during master unregister Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 15/18] drivers/fsi: Add FSI bus documentation Christopher Bostic
2017-02-07 17:23 ` Rob Herring
2017-02-01 16:53 ` [PATCH v3 16/18] drivers/fsi: Add documentation for GPIO based FSI master Christopher Bostic
2017-02-07 17:27 ` Rob Herring
2017-02-01 16:53 ` [PATCH v3 17/18] drivers/fsi: Document FSI master sysfs files in ABI Christopher Bostic
2017-02-01 16:53 ` [PATCH v3 18/18] drivers/fsi: Add GPIO based FSI master Christopher Bostic
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