Commit 4b615be5 authored by Corey Minyard's avatar Corey Minyard Committed by Paolo Bonzini
Browse files

i2c: pm_smbus: Fix the semantics of block I2C transfers 



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: default avatarCorey 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: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent b8fb9043

hw/i2c/pm_smbus.c

+8 −2
Original line number Diff line number Diff line
@@ -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;

hw/i2c/smbus.c

+24 −13
Original line number Diff line number Diff line
@@ -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 (send_cmd) {

        if (i2c_start_transfer(bus, addr, 0)) {

            return -1;

        }

        i2c_send(bus, command);

    }

    if (i2c_start_transfer(bus, addr, 1)) {

        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;

    }

    if (rlen > len) {

        rlen = 0;

    }

    for (i = 0; i < len; i++) {

    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);

    if (send_len) {

        i2c_send(bus, len);

    }

    for (i = 0; i < len; i++) {

        i2c_send(bus, data[i]);

    }

include/hw/i2c/smbus.h

+15 −2
Original line number Diff line number Diff line
@@ -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,