cxgb4: Add support for ethtool i2c dump

Adds support for ethtool get_module_info() and get_module_eeprom()
callbacks that will dump necessary information for a SFP.

Signed-off-by: Arjun Vynipadath <arjun@chelsio.com>
Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -1424,6 +1424,21 @@ static inline void init_rspq(struct adapter *adap, struct sge_rspq *q,
 	q->size = size;
 }
 
+/**
+ *     t4_is_inserted_mod_type - is a plugged in Firmware Module Type
+ *     @fw_mod_type: the Firmware Mofule Type
+ *
+ *     Return whether the Firmware Module Type represents a real Transceiver
+ *     Module/Cable Module Type which has been inserted.
+ */
+static inline bool t4_is_inserted_mod_type(unsigned int fw_mod_type)
+{
+	return (fw_mod_type != FW_PORT_MOD_TYPE_NONE &&
+		fw_mod_type != FW_PORT_MOD_TYPE_NOTSUPPORTED &&
+		fw_mod_type != FW_PORT_MOD_TYPE_UNKNOWN &&
+		fw_mod_type != FW_PORT_MOD_TYPE_ERROR);
+}
+
 void t4_write_indirect(struct adapter *adap, unsigned int addr_reg,
 		       unsigned int data_reg, const u32 *vals,
 		       unsigned int nregs, unsigned int start_idx);
@@ -1697,6 +1712,9 @@ void t4_uld_mem_free(struct adapter *adap);
 int t4_uld_mem_alloc(struct adapter *adap);
 void t4_uld_clean_up(struct adapter *adap);
 void t4_register_netevent_notifier(void);
+int t4_i2c_rd(struct adapter *adap, unsigned int mbox, int port,
+	      unsigned int devid, unsigned int offset,
+	      unsigned int len, u8 *buf);
 void free_rspq_fl(struct adapter *adap, struct sge_rspq *rq, struct sge_fl *fl);
 void free_tx_desc(struct adapter *adap, struct sge_txq *q,
 		  unsigned int n, bool unmap);

drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c

@@ -1396,6 +1396,101 @@ static int get_dump_data(struct net_device *dev, struct ethtool_dump *eth_dump,
 	return 0;
 }
 
+static int cxgb4_get_module_info(struct net_device *dev,
+				 struct ethtool_modinfo *modinfo)
+{
+	struct port_info *pi = netdev_priv(dev);
+	u8 sff8472_comp, sff_diag_type, sff_rev;
+	struct adapter *adapter = pi->adapter;
+	int ret;
+
+	if (!t4_is_inserted_mod_type(pi->mod_type))
+		return -EINVAL;
+
+	switch (pi->port_type) {
+	case FW_PORT_TYPE_SFP:
+	case FW_PORT_TYPE_QSA:
+	case FW_PORT_TYPE_SFP28:
+		ret = t4_i2c_rd(adapter, adapter->mbox, pi->tx_chan,
+				I2C_DEV_ADDR_A0, SFF_8472_COMP_ADDR,
+				SFF_8472_COMP_LEN, &sff8472_comp);
+		if (ret)
+			return ret;
+		ret = t4_i2c_rd(adapter, adapter->mbox, pi->tx_chan,
+				I2C_DEV_ADDR_A0, SFP_DIAG_TYPE_ADDR,
+				SFP_DIAG_TYPE_LEN, &sff_diag_type);
+		if (ret)
+			return ret;
+
+		if (!sff8472_comp || (sff_diag_type & 4)) {
+			modinfo->type = ETH_MODULE_SFF_8079;
+			modinfo->eeprom_len = ETH_MODULE_SFF_8079_LEN;
+		} else {
+			modinfo->type = ETH_MODULE_SFF_8472;
+			modinfo->eeprom_len = ETH_MODULE_SFF_8472_LEN;
+		}
+		break;
+
+	case FW_PORT_TYPE_QSFP:
+	case FW_PORT_TYPE_QSFP_10G:
+	case FW_PORT_TYPE_CR_QSFP:
+	case FW_PORT_TYPE_CR2_QSFP:
+	case FW_PORT_TYPE_CR4_QSFP:
+		ret = t4_i2c_rd(adapter, adapter->mbox, pi->tx_chan,
+				I2C_DEV_ADDR_A0, SFF_REV_ADDR,
+				SFF_REV_LEN, &sff_rev);
+		/* For QSFP type ports, revision value >= 3
+		 * means the SFP is 8636 compliant.
+		 */
+		if (ret)
+			return ret;
+		if (sff_rev >= 0x3) {
+			modinfo->type = ETH_MODULE_SFF_8636;
+			modinfo->eeprom_len = ETH_MODULE_SFF_8636_LEN;
+		} else {
+			modinfo->type = ETH_MODULE_SFF_8436;
+			modinfo->eeprom_len = ETH_MODULE_SFF_8436_LEN;
+		}
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cxgb4_get_module_eeprom(struct net_device *dev,
+				   struct ethtool_eeprom *eprom, u8 *data)
+{
+	int ret = 0, offset = eprom->offset, len = eprom->len;
+	struct port_info *pi = netdev_priv(dev);
+	struct adapter *adapter = pi->adapter;
+
+	memset(data, 0, eprom->len);
+	if (offset + len <= I2C_PAGE_SIZE)
+		return t4_i2c_rd(adapter, adapter->mbox, pi->tx_chan,
+				 I2C_DEV_ADDR_A0, offset, len, data);
+
+	/* offset + len spans 0xa0 and 0xa1 pages */
+	if (offset <= I2C_PAGE_SIZE) {
+		/* read 0xa0 page */
+		len = I2C_PAGE_SIZE - offset;
+		ret =  t4_i2c_rd(adapter, adapter->mbox, pi->tx_chan,
+				 I2C_DEV_ADDR_A0, offset, len, data);
+		if (ret)
+			return ret;
+		offset = I2C_PAGE_SIZE;
+		/* Remaining bytes to be read from second page =
+		 * Total length - bytes read from first page
+		 */
+		len = eprom->len - len;
+	}
+	/* Read additional optical diagnostics from page 0xa2 if supported */
+	return t4_i2c_rd(adapter, adapter->mbox, pi->tx_chan, I2C_DEV_ADDR_A2,
+			 offset, len, &data[eprom->len - len]);
+}
+
 static const struct ethtool_ops cxgb_ethtool_ops = {
 	.get_link_ksettings = get_link_ksettings,
 	.set_link_ksettings = set_link_ksettings,
@@ -1430,6 +1525,8 @@ static const struct ethtool_ops cxgb_ethtool_ops = {
 	.set_dump          = set_dump,
 	.get_dump_flag     = get_dump_flag,
 	.get_dump_data     = get_dump_data,
+	.get_module_info   = cxgb4_get_module_info,
+	.get_module_eeprom = cxgb4_get_module_eeprom,
 };
 
 void cxgb4_set_ethtool_ops(struct net_device *netdev)

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

@@ -9743,3 +9743,59 @@ int t4_sched_params(struct adapter *adapter, int type, int level, int mode,
 	return t4_wr_mbox_meat(adapter, adapter->mbox, &cmd, sizeof(cmd),
 			       NULL, 1);
 }
+
+/**
+ *	t4_i2c_rd - read I2C data from adapter
+ *	@adap: the adapter
+ *	@port: Port number if per-port device; <0 if not
+ *	@devid: per-port device ID or absolute device ID
+ *	@offset: byte offset into device I2C space
+ *	@len: byte length of I2C space data
+ *	@buf: buffer in which to return I2C data
+ *
+ *	Reads the I2C data from the indicated device and location.
+ */
+int t4_i2c_rd(struct adapter *adap, unsigned int mbox, int port,
+	      unsigned int devid, unsigned int offset,
+	      unsigned int len, u8 *buf)
+{
+	struct fw_ldst_cmd ldst_cmd, ldst_rpl;
+	unsigned int i2c_max = sizeof(ldst_cmd.u.i2c.data);
+	int ret = 0;
+
+	if (len > I2C_PAGE_SIZE)
+		return -EINVAL;
+
+	/* Dont allow reads that spans multiple pages */
+	if (offset < I2C_PAGE_SIZE && offset + len > I2C_PAGE_SIZE)
+		return -EINVAL;
+
+	memset(&ldst_cmd, 0, sizeof(ldst_cmd));
+	ldst_cmd.op_to_addrspace =
+		cpu_to_be32(FW_CMD_OP_V(FW_LDST_CMD) |
+			    FW_CMD_REQUEST_F |
+			    FW_CMD_READ_F |
+			    FW_LDST_CMD_ADDRSPACE_V(FW_LDST_ADDRSPC_I2C));
+	ldst_cmd.cycles_to_len16 = cpu_to_be32(FW_LEN16(ldst_cmd));
+	ldst_cmd.u.i2c.pid = (port < 0 ? 0xff : port);
+	ldst_cmd.u.i2c.did = devid;
+
+	while (len > 0) {
+		unsigned int i2c_len = (len < i2c_max) ? len : i2c_max;
+
+		ldst_cmd.u.i2c.boffset = offset;
+		ldst_cmd.u.i2c.blen = i2c_len;
+
+		ret = t4_wr_mbox(adap, mbox, &ldst_cmd, sizeof(ldst_cmd),
+				 &ldst_rpl);
+		if (ret)
+			break;
+
+		memcpy(buf, ldst_rpl.u.i2c.data, i2c_len);
+		offset += i2c_len;
+		buf += i2c_len;
+		len -= i2c_len;
+	}
+
+	return ret;
+}

drivers/net/ethernet/chelsio/cxgb4/t4_hw.h

@@ -286,4 +286,14 @@ enum {
 #define SGE_TIMESTAMP_V(x) ((__u64)(x) << SGE_TIMESTAMP_S)
 #define SGE_TIMESTAMP_G(x) (((__u64)(x) >> SGE_TIMESTAMP_S) & SGE_TIMESTAMP_M)
 
+#define I2C_DEV_ADDR_A0		0xa0
+#define I2C_DEV_ADDR_A2		0xa2
+#define I2C_PAGE_SIZE		0x100
+#define SFP_DIAG_TYPE_ADDR	0x5c
+#define SFP_DIAG_TYPE_LEN	0x1
+#define SFF_8472_COMP_ADDR	0x5e
+#define SFF_8472_COMP_LEN	0x1
+#define SFF_REV_ADDR		0x1
+#define SFF_REV_LEN		0x1
+
 #endif /* __T4_HW_H */

drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h

@@ -828,6 +828,7 @@ enum fw_ldst_addrspc {
 	FW_LDST_ADDRSPC_MPS       = 0x0020,
 	FW_LDST_ADDRSPC_FUNC      = 0x0028,
 	FW_LDST_ADDRSPC_FUNC_PCIE = 0x0029,
+	FW_LDST_ADDRSPC_I2C       = 0x0038,
 };
 
 enum fw_ldst_mps_fid {