Index: /i2c/trunk/kernel/i2c-core.c =================================================================== --- /i2c/trunk/kernel/i2c-core.c (revision 4004) +++ /i2c/trunk/kernel/i2c-core.c (revision 4014) @@ -20,5 +20,6 @@ /* With some changes from Kyösti Mälkki . All SMBus-related things are written by Frodo Looijaard - SMBus 2.0 support by Mark Studebaker */ + SMBus 2.0 support by Mark Studebaker and + Jean Delvare */ /* i2c-core.c,v 1.91.2.2 2003/01/21 10:00:19 kmalkki Exp */ @@ -943,99 +944,42 @@ } -/* CRC over count bytes in the first array plus the bytes in the rest - array if it is non-null. rest[0] is the (length of rest) - 1 - and is included. */ -u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest) +/* Incremental CRC8 over count bytes in the array pointed to by p */ +static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) { int i; for(i = 0; i < count; i++) - crc = crc8((crc ^ first[i]) << 8); - if(rest != NULL) - for(i = 0; i <= rest[0]; i++) - crc = crc8((crc ^ rest[i]) << 8); + crc = crc8((crc ^ p[i]) << 8); return crc; } -u8 i2c_smbus_pec(int count, u8 *first, u8 *rest) -{ - return i2c_smbus_partial_pec(0, count, first, rest); -} - -/* Returns new "size" (transaction type) - Note that we convert byte to byte_data and byte_data to word_data - rather than invent new xxx_PEC transactions. */ -int i2c_smbus_add_pec(u16 addr, u8 command, int size, - union i2c_smbus_data *data) -{ - u8 buf[3]; - - buf[0] = addr << 1; - buf[1] = command; - switch(size) { - case I2C_SMBUS_BYTE: - data->byte = i2c_smbus_pec(2, buf, NULL); - size = I2C_SMBUS_BYTE_DATA; - break; - case I2C_SMBUS_BYTE_DATA: - buf[2] = data->byte; - data->word = buf[2] | - (i2c_smbus_pec(3, buf, NULL) << 8); - size = I2C_SMBUS_WORD_DATA; - break; - case I2C_SMBUS_WORD_DATA: - /* unsupported */ - break; - case I2C_SMBUS_BLOCK_DATA: - data->block[data->block[0] + 1] = - i2c_smbus_pec(2, buf, data->block); - size = I2C_SMBUS_BLOCK_DATA_PEC; - break; - } - return size; -} - -int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial, - union i2c_smbus_data *data) -{ - u8 buf[3], rpec, cpec; - - buf[1] = command; - switch(size) { - case I2C_SMBUS_BYTE_DATA: - buf[0] = (addr << 1) | 1; - cpec = i2c_smbus_pec(2, buf, NULL); - rpec = data->byte; - break; - case I2C_SMBUS_WORD_DATA: - buf[0] = (addr << 1) | 1; - buf[2] = data->word & 0xff; - cpec = i2c_smbus_pec(3, buf, NULL); - rpec = data->word >> 8; - break; - case I2C_SMBUS_WORD_DATA_PEC: - /* unsupported */ - cpec = rpec = 0; - break; - case I2C_SMBUS_PROC_CALL_PEC: - /* unsupported */ - cpec = rpec = 0; - break; - case I2C_SMBUS_BLOCK_DATA_PEC: - buf[0] = (addr << 1); - buf[2] = (addr << 1) | 1; - cpec = i2c_smbus_pec(3, buf, data->block); - rpec = data->block[data->block[0] + 1]; - break; - case I2C_SMBUS_BLOCK_PROC_CALL_PEC: - buf[0] = (addr << 1) | 1; - rpec = i2c_smbus_partial_pec(partial, 1, - buf, data->block); - cpec = data->block[data->block[0] + 1]; - break; - default: - cpec = rpec = 0; - break; - } +/* Assume a 7-bit address, which is reasonable for SMBus */ +static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) +{ + /* The address will be sent first */ + u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); + pec = i2c_smbus_pec(pec, &addr, 1); + + /* The data buffer follows */ + return i2c_smbus_pec(pec, msg->buf, msg->len); +} + +/* Used for write only transactions */ +static inline void i2c_smbus_add_pec(struct i2c_msg *msg) +{ + msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); + msg->len++; +} + +/* Return <0 on CRC error + If there was a write before this read (most cases) we need to take the + partial CRC from the write part into account. + Note that this function does modify the message (we need to decrease the + message length to hide the CRC byte from the caller). */ +int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) +{ + u8 rpec = msg->buf[--msg->len]; + cpec = i2c_smbus_msg_pec(cpec, msg); + if(rpec != cpec) { DEB(printk(KERN_DEBUG "i2c-core.o: Bad PEC 0x%02x vs. 0x%02x\n", @@ -1064,7 +1008,6 @@ extern s32 i2c_smbus_write_byte(struct i2c_client * client, u8 value) { - union i2c_smbus_data data; /* only for PEC */ return i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data); + I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); } @@ -1224,4 +1167,5 @@ }; int i, len; + u8 partial_pec = 0; msgbuf0[0] = command; @@ -1266,5 +1210,4 @@ break; case I2C_SMBUS_BLOCK_DATA: - case I2C_SMBUS_BLOCK_DATA_PEC: if (read_write == I2C_SMBUS_READ) { /* I2C_FUNC_SMBUS_EMUL doesn't include I2C_FUNC_SMBUS_READ_BLOCK_DATA */ @@ -1279,8 +1222,6 @@ msg[1].flags |= I2C_M_RECV_LEN; msg[1].len = I2C_SMBUS_BLOCK_MAX + 1; - if (size == I2C_SMBUS_BLOCK_DATA_PEC) { - msg[1].len++; + if (flags & I2C_CLIENT_PEC) msg[1].flags |= I2C_M_RECV_PEC; - } } else { msg[0].len = data->block[0] + 2; @@ -1291,6 +1232,4 @@ return -1; } - if(size == I2C_SMBUS_BLOCK_DATA_PEC) - (msg[0].len)++; for (i = 1; i < msg[0].len; i++) msgbuf0[i] = data->block[i-1]; @@ -1298,5 +1237,4 @@ break; case I2C_SMBUS_BLOCK_PROC_CALL: - case I2C_SMBUS_BLOCK_PROC_CALL_PEC: /* I2C_FUNC_SMBUS_EMUL doesn't include I2C_FUNC_SMBUS_BLOCK_PROC_CALL */ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BLOCK_PROC_CALL)) { @@ -1322,8 +1260,6 @@ msg[1].flags |= I2C_M_RECV_LEN; msg[1].len = I2C_SMBUS_BLOCK_MAX + 1; - if (size == I2C_SMBUS_BLOCK_PROC_CALL_PEC) { - msg[1].len++; + if (flags & I2C_CLIENT_PEC) msg[1].flags |= I2C_M_RECV_PEC; - } break; case I2C_SMBUS_I2C_BLOCK_DATA: @@ -1348,6 +1284,27 @@ } + i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK + && size != I2C_SMBUS_I2C_BLOCK_DATA); + if (i) { + /* Compute PEC if first message is a write */ + if (!(msg[0].flags & I2C_M_RD)) { + if (num == 1) /* Write only */ + i2c_smbus_add_pec(&msg[0]); + else /* Write followed by read */ + partial_pec = i2c_smbus_msg_pec(0, &msg[0]); + } + /* Ask for PEC if last message is a read */ + if (msg[num-1].flags & I2C_M_RD) + msg[num-1].len++; + } + if (i2c_transfer(adapter, msg, num) < 0) return -1; + + /* Check PEC if last message is a read */ + if (i && (msg[num-1].flags & I2C_M_RD)) { + if (i2c_smbus_check_pec(partial_pec, &msg[num-1]) < 0) + return -1; + } if (read_write == I2C_SMBUS_READ) @@ -1371,10 +1328,5 @@ case I2C_SMBUS_BLOCK_DATA: case I2C_SMBUS_BLOCK_PROC_CALL: - case I2C_SMBUS_BLOCK_DATA_PEC: - case I2C_SMBUS_BLOCK_PROC_CALL_PEC: len = msgbuf1[0] + 1; - if(size == I2C_SMBUS_BLOCK_DATA_PEC || - size == I2C_SMBUS_BLOCK_PROC_CALL_PEC) - len++; for (i = 0; i < len; i++) data->block[i] = msgbuf1[i]; @@ -1390,26 +1342,6 @@ { s32 res; - int swpec = 0; - u8 partial = 0; flags &= I2C_M_TEN | I2C_CLIENT_PEC; - if((flags & I2C_CLIENT_PEC) && - !(i2c_check_functionality(adap, I2C_FUNC_SMBUS_HWPEC_CALC))) { - swpec = 1; - if(read_write == I2C_SMBUS_READ && - size == I2C_SMBUS_BLOCK_DATA) - size = I2C_SMBUS_BLOCK_DATA_PEC; - else if(size == I2C_SMBUS_PROC_CALL) - size = I2C_SMBUS_PROC_CALL_PEC; - else if(size == I2C_SMBUS_BLOCK_PROC_CALL) { - i2c_smbus_add_pec(addr, command, - I2C_SMBUS_BLOCK_DATA, data); - partial = data->block[data->block[0] + 1]; - size = I2C_SMBUS_BLOCK_PROC_CALL_PEC; - } else if(read_write == I2C_SMBUS_WRITE && - size != I2C_SMBUS_QUICK && - size != I2C_SMBUS_I2C_BLOCK_DATA) - size = i2c_smbus_add_pec(addr, command, size, data); - } if (adap->algo->smbus_xfer) { @@ -1422,11 +1354,4 @@ command,size,data); - if(res >= 0 && swpec && - size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA && - (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC || - size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) { - if(i2c_smbus_check_pec(addr, command, size, partial, data)) - return -1; - } return res; }