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Diffstat (limited to 'drivers/media/common/ttpci-eeprom.c')
-rw-r--r--drivers/media/common/ttpci-eeprom.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/media/common/ttpci-eeprom.c b/drivers/media/common/ttpci-eeprom.c
new file mode 100644
index 0000000000..ef8746684d
--- /dev/null
+++ b/drivers/media/common/ttpci-eeprom.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ Retrieve encoded MAC address from 24C16 serial 2-wire EEPROM,
+ decode it and store it in the associated adapter struct for
+ use by dvb_net.c
+
+ This card appear to have the 24C16 write protect held to ground,
+ thus permitting normal read/write operation. Theoretically it
+ would be possible to write routines to burn a different (encoded)
+ MAC address into the EEPROM.
+
+ Robert Schlabbach GMX
+ Michael Glaum KVH Industries
+ Holger Waechtler Convergence
+
+ Copyright (C) 2002-2003 Ralph Metzler <rjkm@metzlerbros.de>
+ Metzler Brothers Systementwicklung GbR
+
+
+*/
+
+#include <asm/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/i2c.h>
+#include <linux/etherdevice.h>
+
+#include "ttpci-eeprom.h"
+
+#if 1
+#define dprintk(x...) do { printk(x); } while (0)
+#else
+#define dprintk(x...) do { } while (0)
+#endif
+
+
+static int check_mac_tt(u8 *buf)
+{
+ int i;
+ u16 tmp = 0xffff;
+
+ for (i = 0; i < 8; i++) {
+ tmp = (tmp << 8) | ((tmp >> 8) ^ buf[i]);
+ tmp ^= (tmp >> 4) & 0x0f;
+ tmp ^= (tmp << 12) ^ ((tmp & 0xff) << 5);
+ }
+ tmp ^= 0xffff;
+ return (((tmp >> 8) ^ buf[8]) | ((tmp & 0xff) ^ buf[9]));
+}
+
+static int getmac_tt(u8 * decodedMAC, u8 * encodedMAC)
+{
+ u8 xor[20] = { 0x72, 0x23, 0x68, 0x19, 0x5c, 0xa8, 0x71, 0x2c,
+ 0x54, 0xd3, 0x7b, 0xf1, 0x9E, 0x23, 0x16, 0xf6,
+ 0x1d, 0x36, 0x64, 0x78};
+ u8 data[20];
+ int i;
+
+ /* In case there is a sig check failure have the orig contents available */
+ memcpy(data, encodedMAC, 20);
+
+ for (i = 0; i < 20; i++)
+ data[i] ^= xor[i];
+ for (i = 0; i < 10; i++)
+ data[i] = ((data[2 * i + 1] << 8) | data[2 * i])
+ >> ((data[2 * i + 1] >> 6) & 3);
+
+ if (check_mac_tt(data))
+ return -ENODEV;
+
+ decodedMAC[0] = data[2]; decodedMAC[1] = data[1]; decodedMAC[2] = data[0];
+ decodedMAC[3] = data[6]; decodedMAC[4] = data[5]; decodedMAC[5] = data[4];
+ return 0;
+}
+
+int ttpci_eeprom_decode_mac(u8 *decodedMAC, u8 *encodedMAC)
+{
+ u8 xor[20] = { 0x72, 0x23, 0x68, 0x19, 0x5c, 0xa8, 0x71, 0x2c,
+ 0x54, 0xd3, 0x7b, 0xf1, 0x9E, 0x23, 0x16, 0xf6,
+ 0x1d, 0x36, 0x64, 0x78};
+ u8 data[20];
+ int i;
+
+ memcpy(data, encodedMAC, 20);
+
+ for (i = 0; i < 20; i++)
+ data[i] ^= xor[i];
+ for (i = 0; i < 10; i++)
+ data[i] = ((data[2 * i + 1] << 8) | data[2 * i])
+ >> ((data[2 * i + 1] >> 6) & 3);
+
+ if (check_mac_tt(data))
+ return -ENODEV;
+
+ decodedMAC[0] = data[2];
+ decodedMAC[1] = data[1];
+ decodedMAC[2] = data[0];
+ decodedMAC[3] = data[6];
+ decodedMAC[4] = data[5];
+ decodedMAC[5] = data[4];
+ return 0;
+}
+EXPORT_SYMBOL(ttpci_eeprom_decode_mac);
+
+static int ttpci_eeprom_read_encodedMAC(struct i2c_adapter *adapter, u8 * encodedMAC)
+{
+ int ret;
+ u8 b0[] = { 0xcc };
+
+ struct i2c_msg msg[] = {
+ { .addr = 0x50, .flags = 0, .buf = b0, .len = 1 },
+ { .addr = 0x50, .flags = I2C_M_RD, .buf = encodedMAC, .len = 20 }
+ };
+
+ /* dprintk("%s\n", __func__); */
+
+ ret = i2c_transfer(adapter, msg, 2);
+
+ if (ret != 2) /* Assume EEPROM isn't there */
+ return (-ENODEV);
+
+ return 0;
+}
+
+
+int ttpci_eeprom_parse_mac(struct i2c_adapter *adapter, u8 *proposed_mac)
+{
+ int ret;
+ u8 encodedMAC[20];
+ u8 decodedMAC[6];
+
+ ret = ttpci_eeprom_read_encodedMAC(adapter, encodedMAC);
+
+ if (ret != 0) { /* Will only be -ENODEV */
+ dprintk("Couldn't read from EEPROM: not there?\n");
+ eth_zero_addr(proposed_mac);
+ return ret;
+ }
+
+ ret = getmac_tt(decodedMAC, encodedMAC);
+ if( ret != 0 ) {
+ dprintk("adapter failed MAC signature check\n");
+ dprintk("encoded MAC from EEPROM was %*phC",
+ (int)sizeof(encodedMAC), &encodedMAC);
+ eth_zero_addr(proposed_mac);
+ return ret;
+ }
+
+ memcpy(proposed_mac, decodedMAC, 6);
+ dprintk("adapter has MAC addr = %pM\n", decodedMAC);
+ return 0;
+}
+
+EXPORT_SYMBOL(ttpci_eeprom_parse_mac);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ralph Metzler, Marcus Metzler, others");
+MODULE_DESCRIPTION("Decode dvb_net MAC address from EEPROM of PCI DVB cards made by Siemens, Technotrend, Hauppauge");