mlxsw: Implement ethtool operation to write to a transceiver module EEPROM

Implement the ethtool_ops::set_module_eeprom_by_page operation to allow
ethtool to write to a transceiver module EEPROM, in a similar fashion to
the ethtool_ops::get_module_eeprom_by_page operation.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/core_env.c

@@ -513,6 +513,63 @@ mlxsw_env_get_module_eeprom_by_page(struct mlxsw_core *mlxsw_core,
 }
 EXPORT_SYMBOL(mlxsw_env_get_module_eeprom_by_page);
 
+int
+mlxsw_env_set_module_eeprom_by_page(struct mlxsw_core *mlxsw_core,
+				    u8 slot_index, u8 module,
+				    const struct ethtool_module_eeprom *page,
+				    struct netlink_ext_ack *extack)
+{
+	struct mlxsw_env *mlxsw_env = mlxsw_core_env(mlxsw_core);
+	u32 bytes_written = 0;
+	u16 device_addr;
+	int err;
+
+	if (!mlxsw_env_linecard_is_active(mlxsw_env, slot_index)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Cannot write to EEPROM of a module on an inactive line card");
+		return -EIO;
+	}
+
+	err = mlxsw_env_validate_module_type(mlxsw_core, slot_index, module);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack, "EEPROM is not equipped on port module type");
+		return err;
+	}
+
+	device_addr = page->offset;
+
+	while (bytes_written < page->length) {
+		char mcia_pl[MLXSW_REG_MCIA_LEN];
+		char eeprom_tmp[128] = {};
+		u8 size;
+
+		size = min_t(u8, page->length - bytes_written,
+			     mlxsw_env->max_eeprom_len);
+
+		mlxsw_reg_mcia_pack(mcia_pl, slot_index, module, page->page,
+				    device_addr + bytes_written, size,
+				    page->i2c_address);
+		mlxsw_reg_mcia_bank_number_set(mcia_pl, page->bank);
+		memcpy(eeprom_tmp, page->data + bytes_written, size);
+		mlxsw_reg_mcia_eeprom_memcpy_to(mcia_pl, eeprom_tmp);
+
+		err = mlxsw_reg_write(mlxsw_core, MLXSW_REG(mcia), mcia_pl);
+		if (err) {
+			NL_SET_ERR_MSG_MOD(extack, "Failed to access module's EEPROM");
+			return err;
+		}
+
+		err = mlxsw_env_mcia_status_process(mcia_pl, extack);
+		if (err)
+			return err;
+
+		bytes_written += size;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(mlxsw_env_set_module_eeprom_by_page);
+
 static int mlxsw_env_module_reset(struct mlxsw_core *mlxsw_core, u8 slot_index,
 				  u8 module)
 {

drivers/net/ethernet/mellanox/mlxsw/core_env.h

@@ -28,6 +28,12 @@ mlxsw_env_get_module_eeprom_by_page(struct mlxsw_core *mlxsw_core,
 				    const struct ethtool_module_eeprom *page,
 				    struct netlink_ext_ack *extack);
 
+int
+mlxsw_env_set_module_eeprom_by_page(struct mlxsw_core *mlxsw_core,
+				    u8 slot_index, u8 module,
+				    const struct ethtool_module_eeprom *page,
+				    struct netlink_ext_ack *extack);
+
 int mlxsw_env_reset_module(struct net_device *netdev,
 			   struct mlxsw_core *mlxsw_core, u8 slot_index,
 			   u8 module, u32 *flags);

drivers/net/ethernet/mellanox/mlxsw/minimal.c

@@ -140,6 +140,20 @@ mlxsw_m_get_module_eeprom_by_page(struct net_device *netdev,
 						   page, extack);
 }
 
+static int
+mlxsw_m_set_module_eeprom_by_page(struct net_device *netdev,
+				  const struct ethtool_module_eeprom *page,
+				  struct netlink_ext_ack *extack)
+{
+	struct mlxsw_m_port *mlxsw_m_port = netdev_priv(netdev);
+	struct mlxsw_core *core = mlxsw_m_port->mlxsw_m->core;
+
+	return mlxsw_env_set_module_eeprom_by_page(core,
+						   mlxsw_m_port->slot_index,
+						   mlxsw_m_port->module,
+						   page, extack);
+}
+
 static int mlxsw_m_reset(struct net_device *netdev, u32 *flags)
 {
 	struct mlxsw_m_port *mlxsw_m_port = netdev_priv(netdev);
@@ -181,6 +195,7 @@ static const struct ethtool_ops mlxsw_m_port_ethtool_ops = {
 	.get_module_info	= mlxsw_m_get_module_info,
 	.get_module_eeprom	= mlxsw_m_get_module_eeprom,
 	.get_module_eeprom_by_page = mlxsw_m_get_module_eeprom_by_page,
+	.set_module_eeprom_by_page = mlxsw_m_set_module_eeprom_by_page,
 	.reset			= mlxsw_m_reset,
 	.get_module_power_mode	= mlxsw_m_get_module_power_mode,
 	.set_module_power_mode	= mlxsw_m_set_module_power_mode,

drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c

@@ -1067,6 +1067,20 @@ mlxsw_sp_get_module_eeprom_by_page(struct net_device *dev,
 						   module, page, extack);
 }
 
+static int
+mlxsw_sp_set_module_eeprom_by_page(struct net_device *dev,
+				   const struct ethtool_module_eeprom *page,
+				   struct netlink_ext_ack *extack)
+{
+	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+	u8 slot_index = mlxsw_sp_port->mapping.slot_index;
+	u8 module = mlxsw_sp_port->mapping.module;
+
+	return mlxsw_env_set_module_eeprom_by_page(mlxsw_sp->core, slot_index,
+						   module, page, extack);
+}
+
 static int
 mlxsw_sp_get_ts_info(struct net_device *netdev, struct ethtool_ts_info *info)
 {
@@ -1256,6 +1270,7 @@ const struct ethtool_ops mlxsw_sp_port_ethtool_ops = {
 	.get_module_info		= mlxsw_sp_get_module_info,
 	.get_module_eeprom		= mlxsw_sp_get_module_eeprom,
 	.get_module_eeprom_by_page	= mlxsw_sp_get_module_eeprom_by_page,
+	.set_module_eeprom_by_page	= mlxsw_sp_set_module_eeprom_by_page,
 	.get_ts_info			= mlxsw_sp_get_ts_info,
 	.get_eth_phy_stats		= mlxsw_sp_get_eth_phy_stats,
 	.get_eth_mac_stats		= mlxsw_sp_get_eth_mac_stats,