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i2c: pm_smbus: Fix the semantics of block I2C transfers

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The I2C block transfer commands was not implemented correctly, it
read a length byte and such like it was an smbus transfer.

So fix the smbus_read_block() and smbus_write_block() functions
so they can properly handle I2C transfers, and normal SMBus
transfers (for upcoming changes).  Pass in a transfer size and
a bool to know whether to use the size byte (like SMBus) or use
the length given (like I2C).

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1534796770-10295-3-git-send-email-minyard@acm.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Corey Minyard 2018-08-20 15:26:02 -05:00 committed by Paolo Bonzini
parent b8fb9043eb
commit 4b615be540
3 changed files with 47 additions and 17 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
hw/i2c/pm_smbus.c
View file

@ -117,10 +117,16 @@ static void smb_transaction(PMSMBus *s)
break;
case PROT_I2C_BLOCK_DATA:
if (read) {
ret = smbus_read_block(bus, addr, cmd, s->smb_data);
int xfersize = s->smb_data0;
if (xfersize > sizeof(s->smb_data)) {
xfersize = sizeof(s->smb_data);
}
ret = smbus_read_block(bus, addr, s->smb_data1, s->smb_data,
xfersize, false, true);
goto data8;
} else {
ret = smbus_write_block(bus, addr, cmd, s->smb_data, s->smb_data0);
ret = smbus_write_block(bus, addr, cmd, s->smb_data, s->smb_data0,
false);
goto done;
}
break;

37
hw/i2c/smbus.c
View file

@ -293,33 +293,42 @@ int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data)
return 0;
}
int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data)
int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
int len, bool recv_len, bool send_cmd)
{
int len;
int rlen;
int i;
if (i2c_start_transfer(bus, addr, 0)) {
return -1;
if (send_cmd) {
if (i2c_start_transfer(bus, addr, 0)) {
return -1;
}
i2c_send(bus, command);
}
i2c_send(bus, command);
if (i2c_start_transfer(bus, addr, 1)) {
i2c_end_transfer(bus);
if (send_cmd) {
i2c_end_transfer(bus);
}
return -1;
}
len = i2c_recv(bus);
if (len > 32) {
len = 0;
if (recv_len) {
rlen = i2c_recv(bus);
} else {
rlen = len;
}
for (i = 0; i < len; i++) {
if (rlen > len) {
rlen = 0;
}
for (i = 0; i < rlen; i++) {
data[i] = i2c_recv(bus);
}
i2c_nack(bus);
i2c_end_transfer(bus);
return len;
return rlen;
}
int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
int len)
int len, bool send_len)
{
int i;
@ -330,7 +339,9 @@ int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
return -1;
}
i2c_send(bus, command);
i2c_send(bus, len);
if (send_len) {
i2c_send(bus, len);
}
for (i = 0; i < len; i++) {
i2c_send(bus, data[i]);
}

17
include/hw/i2c/smbus.h
View file

@ -72,9 +72,22 @@ int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command);
int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data);
int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command);
int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data);
int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data);
/*
* Do a block transfer from an I2C device. If recv_len is set, then the
* first received byte is a length field and is used to know how much data
* to receive. Otherwise receive "len" bytes. If send_cmd is set, send
* the command byte first before receiving the data.
*/
int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
int len, bool recv_len, bool send_cmd);
/*
* Do a block transfer to an I2C device. If send_len is set, send the
* "len" value before the data.
*/
int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data,
int len);
int len, bool send_len);
void smbus_eeprom_init_one(I2CBus *smbus, uint8_t address, uint8_t *eeprom_buf);
void smbus_eeprom_init(I2CBus *smbus, int nb_eeprom,