bcma: read SPROM and extract MAC from it

In case of BCMA cards SPROM is located in the ChipCommon core, it is
not mapped as separated host window. So far we have met only SPROMs rev
8.
SPROM layout seems to be the same as for SSB buses, so we decided to
share SPROM struct and some defines.
For now we extract MAC address only, this can be improved of course.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 162 insertions, 0 deletions

diff --git a/drivers/bcma/sprom.c b/drivers/bcma/sprom.c
new file mode 100644
index 000000000000..ffbb0e32e921
--- /dev/null
+++ b/drivers/bcma/sprom.c
@@ -0,0 +1,162 @@
+/*
+ * Broadcom specific AMBA
+ * SPROM reading
+ *
+ * Licensed under the GNU/GPL. See COPYING for details.
+ */
+
+#include "bcma_private.h"
+
+#include <linux/bcma/bcma.h>
+#include <linux/bcma/bcma_regs.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+
+#define SPOFF(offset)	((offset) / sizeof(u16))
+
+/**************************************************
+ * R/W ops.
+ **************************************************/
+
+static void bcma_sprom_read(struct bcma_bus *bus, u16 *sprom)
+{
+	int i;
+	for (i = 0; i < SSB_SPROMSIZE_WORDS_R4; i++)
+		sprom[i] = bcma_read16(bus->drv_cc.core,
+				       BCMA_CC_SPROM + (i * 2));
+}
+
+/**************************************************
+ * Validation.
+ **************************************************/
+
+static inline u8 bcma_crc8(u8 crc, u8 data)
+{
+	/* Polynomial:   x^8 + x^7 + x^6 + x^4 + x^2 + 1   */
+	static const u8 t[] = {
+		0x00, 0xF7, 0xB9, 0x4E, 0x25, 0xD2, 0x9C, 0x6B,
+		0x4A, 0xBD, 0xF3, 0x04, 0x6F, 0x98, 0xD6, 0x21,
+		0x94, 0x63, 0x2D, 0xDA, 0xB1, 0x46, 0x08, 0xFF,
+		0xDE, 0x29, 0x67, 0x90, 0xFB, 0x0C, 0x42, 0xB5,
+		0x7F, 0x88, 0xC6, 0x31, 0x5A, 0xAD, 0xE3, 0x14,
+		0x35, 0xC2, 0x8C, 0x7B, 0x10, 0xE7, 0xA9, 0x5E,
+		0xEB, 0x1C, 0x52, 0xA5, 0xCE, 0x39, 0x77, 0x80,
+		0xA1, 0x56, 0x18, 0xEF, 0x84, 0x73, 0x3D, 0xCA,
+		0xFE, 0x09, 0x47, 0xB0, 0xDB, 0x2C, 0x62, 0x95,
+		0xB4, 0x43, 0x0D, 0xFA, 0x91, 0x66, 0x28, 0xDF,
+		0x6A, 0x9D, 0xD3, 0x24, 0x4F, 0xB8, 0xF6, 0x01,
+		0x20, 0xD7, 0x99, 0x6E, 0x05, 0xF2, 0xBC, 0x4B,
+		0x81, 0x76, 0x38, 0xCF, 0xA4, 0x53, 0x1D, 0xEA,
+		0xCB, 0x3C, 0x72, 0x85, 0xEE, 0x19, 0x57, 0xA0,
+		0x15, 0xE2, 0xAC, 0x5B, 0x30, 0xC7, 0x89, 0x7E,
+		0x5F, 0xA8, 0xE6, 0x11, 0x7A, 0x8D, 0xC3, 0x34,
+		0xAB, 0x5C, 0x12, 0xE5, 0x8E, 0x79, 0x37, 0xC0,
+		0xE1, 0x16, 0x58, 0xAF, 0xC4, 0x33, 0x7D, 0x8A,
+		0x3F, 0xC8, 0x86, 0x71, 0x1A, 0xED, 0xA3, 0x54,
+		0x75, 0x82, 0xCC, 0x3B, 0x50, 0xA7, 0xE9, 0x1E,
+		0xD4, 0x23, 0x6D, 0x9A, 0xF1, 0x06, 0x48, 0xBF,
+		0x9E, 0x69, 0x27, 0xD0, 0xBB, 0x4C, 0x02, 0xF5,
+		0x40, 0xB7, 0xF9, 0x0E, 0x65, 0x92, 0xDC, 0x2B,
+		0x0A, 0xFD, 0xB3, 0x44, 0x2F, 0xD8, 0x96, 0x61,
+		0x55, 0xA2, 0xEC, 0x1B, 0x70, 0x87, 0xC9, 0x3E,
+		0x1F, 0xE8, 0xA6, 0x51, 0x3A, 0xCD, 0x83, 0x74,
+		0xC1, 0x36, 0x78, 0x8F, 0xE4, 0x13, 0x5D, 0xAA,
+		0x8B, 0x7C, 0x32, 0xC5, 0xAE, 0x59, 0x17, 0xE0,
+		0x2A, 0xDD, 0x93, 0x64, 0x0F, 0xF8, 0xB6, 0x41,
+		0x60, 0x97, 0xD9, 0x2E, 0x45, 0xB2, 0xFC, 0x0B,
+		0xBE, 0x49, 0x07, 0xF0, 0x9B, 0x6C, 0x22, 0xD5,
+		0xF4, 0x03, 0x4D, 0xBA, 0xD1, 0x26, 0x68, 0x9F,
+	};
+	return t[crc ^ data];
+}
+
+static u8 bcma_sprom_crc(const u16 *sprom)
+{
+	int word;
+	u8 crc = 0xFF;
+
+	for (word = 0; word < SSB_SPROMSIZE_WORDS_R4 - 1; word++) {
+		crc = bcma_crc8(crc, sprom[word] & 0x00FF);
+		crc = bcma_crc8(crc, (sprom[word] & 0xFF00) >> 8);
+	}
+	crc = bcma_crc8(crc, sprom[SSB_SPROMSIZE_WORDS_R4 - 1] & 0x00FF);
+	crc ^= 0xFF;
+
+	return crc;
+}
+
+static int bcma_sprom_check_crc(const u16 *sprom)
+{
+	u8 crc;
+	u8 expected_crc;
+	u16 tmp;
+
+	crc = bcma_sprom_crc(sprom);
+	tmp = sprom[SSB_SPROMSIZE_WORDS_R4 - 1] & SSB_SPROM_REVISION_CRC;
+	expected_crc = tmp >> SSB_SPROM_REVISION_CRC_SHIFT;
+	if (crc != expected_crc)
+		return -EPROTO;
+
+	return 0;
+}
+
+static int bcma_sprom_valid(const u16 *sprom)
+{
+	u16 revision;
+	int err;
+
+	err = bcma_sprom_check_crc(sprom);
+	if (err)
+		return err;
+
+	revision = sprom[SSB_SPROMSIZE_WORDS_R4 - 1] & SSB_SPROM_REVISION_REV;
+	if (revision != 8) {
+		pr_err("Unsupported SPROM revision: %d\n", revision);
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+/**************************************************
+ * SPROM extraction.
+ **************************************************/
+
+static void bcma_sprom_extract_r8(struct bcma_bus *bus, const u16 *sprom)
+{
+	u16 v;
+	int i;
+
+	for (i = 0; i < 3; i++) {
+		v = sprom[SPOFF(SSB_SPROM8_IL0MAC) + i];
+		*(((__be16 *)bus->sprom.il0mac) + i) = cpu_to_be16(v);
+	}
+}
+
+int bcma_sprom_get(struct bcma_bus *bus)
+{
+	u16 *sprom;
+	int err = 0;
+
+	if (!bus->drv_cc.core)
+		return -EOPNOTSUPP;
+
+	sprom = kcalloc(SSB_SPROMSIZE_WORDS_R4, sizeof(u16),
+			GFP_KERNEL);
+	if (!sprom)
+		return -ENOMEM;
+
+	bcma_sprom_read(bus, sprom);
+
+	err = bcma_sprom_valid(sprom);
+	if (err)
+		goto out;
+
+	bcma_sprom_extract_r8(bus, sprom);
+
+out:
+	kfree(sprom);
+	return err;
+}