From: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx> The Group Command Protocol is used to send commands to more than one PMBus device. Some devices working together require that they must execute some commands all at once. The commands are sent in one continuous transmission. When the devices detect the STOP condition that ends the sending of commands, they all begin executing the command they received. This patch adds support for the group command protocol. Signed-off-by: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx> --- drivers/hwmon/pmbus/adm1266.c | 50 +++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c index c06465100320..34bd4e652729 100644 --- a/drivers/hwmon/pmbus/adm1266.c +++ b/drivers/hwmon/pmbus/adm1266.c @@ -73,6 +73,56 @@ static const struct nvmem_cell_info adm1266_nvmem_cells[] = { DECLARE_CRC8_TABLE(pmbus_crc_table); +/* PMBus Group command. */ +static int adm1266_pmbus_group_command(struct adm1266_data *data, struct i2c_client **clients, + u8 nr_clients, u8 cmd, u8 w_len, u8 *data_w) +{ + struct i2c_msg *msgs; + u8 addr; + int ret; + int i; + + msgs = kcalloc(nr_clients, sizeof(struct i2c_msg), GFP_KERNEL); + if (!msgs) + return -ENOMEM; + + for (i = 0; i < nr_clients; i++) { + msgs[i].addr = clients[i]->addr; + msgs[i].len = w_len + 1; + + msgs[i].buf = kcalloc(ADM1266_PMBUS_BLOCK_MAX + 2, sizeof(u8), GFP_KERNEL); + if (!msgs[i].buf) { + ret = -ENOMEM; + goto cleanup; + } + + msgs[i].buf[0] = cmd; + memcpy(&msgs[i].buf[1], data_w, w_len); + + if (clients[i]->flags & I2C_CLIENT_PEC) { + u8 crc = 0; + + addr = i2c_8bit_addr_from_msg(&msgs[i]); + crc = crc8(pmbus_crc_table, &addr, 1, crc); + crc = crc8(pmbus_crc_table, msgs[i].buf, msgs[i].len, + crc); + + msgs[i].buf[msgs[i].len] = crc; + msgs[i].len++; + } + }; + + ret = i2c_transfer(data->client->adapter, msgs, nr_clients); + +cleanup: + for (i = i - 1; i >= 0; i--) + kfree(msgs[i].buf); + + kfree(msgs); + + return ret; +} + /* * Different from Block Read as it sends data and waits for the slave to * return a value dependent on that data. The protocol is simply a Write Block -- 2.20.1