net/macb: Adding comments to various #defs to make interpretation easier

This change is to help improve at-a-glace knowledge of the purpose of the
various Cadence MACB/GEM registers. Comments are more helpful for human
readability than short acronyms.

Describe various #define varibles Cadence MACB/GEM registers as documented
in Xilinix's "Zynq-7000 All Programmable SoC TechnicalReference Manual, v1.9.1
(UG-585)"

Signed-off-by: Xander Huff <xander.huff@ni.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb.h

@@ -15,20 +15,20 @@
 #define MACB_MAX_QUEUES 8
 
 /* MACB register offsets */
-#define MACB_NCR				0x0000
-#define MACB_NCFGR				0x0004
-#define MACB_NSR				0x0008
+#define MACB_NCR				0x0000 /* Network Control */
+#define MACB_NCFGR				0x0004 /* Network Config */
+#define MACB_NSR				0x0008 /* Network Status */
 #define MACB_TAR				0x000c /* AT91RM9200 only */
 #define MACB_TCR				0x0010 /* AT91RM9200 only */
-#define MACB_TSR				0x0014
-#define MACB_RBQP				0x0018
-#define MACB_TBQP				0x001c
-#define MACB_RSR				0x0020
-#define MACB_ISR				0x0024
-#define MACB_IER				0x0028
-#define MACB_IDR				0x002c
-#define MACB_IMR				0x0030
-#define MACB_MAN				0x0034
+#define MACB_TSR				0x0014 /* Transmit Status */
+#define MACB_RBQP				0x0018 /* RX Q Base Address */
+#define MACB_TBQP				0x001c /* TX Q Base Address */
+#define MACB_RSR				0x0020 /* Receive Status */
+#define MACB_ISR				0x0024 /* Interrupt Status */
+#define MACB_IER				0x0028 /* Interrupt Enable */
+#define MACB_IDR				0x002c /* Interrupt Disable */
+#define MACB_IMR				0x0030 /* Interrupt Mask */
+#define MACB_MAN				0x0034 /* PHY Maintenance */
 #define MACB_PTR				0x0038
 #define MACB_PFR				0x003c
 #define MACB_FTO				0x0040
@@ -68,27 +68,27 @@
 #define MACB_MID				0x00fc
 
 /* GEM register offsets. */
-#define GEM_NCFGR				0x0004
-#define GEM_USRIO				0x000c
-#define GEM_DMACFG				0x0010
-#define GEM_HRB					0x0080
-#define GEM_HRT					0x0084
-#define GEM_SA1B				0x0088
-#define GEM_SA1T				0x008C
-#define GEM_SA2B				0x0090
-#define GEM_SA2T				0x0094
-#define GEM_SA3B				0x0098
-#define GEM_SA3T				0x009C
-#define GEM_SA4B				0x00A0
-#define GEM_SA4T				0x00A4
-#define GEM_OTX					0x0100
-#define GEM_DCFG1				0x0280
-#define GEM_DCFG2				0x0284
-#define GEM_DCFG3				0x0288
-#define GEM_DCFG4				0x028c
-#define GEM_DCFG5				0x0290
-#define GEM_DCFG6				0x0294
-#define GEM_DCFG7				0x0298
+#define GEM_NCFGR				0x0004 /* Network Config */
+#define GEM_USRIO				0x000c /* User IO */
+#define GEM_DMACFG				0x0010 /* DMA Configuration */
+#define GEM_HRB					0x0080 /* Hash Bottom */
+#define GEM_HRT					0x0084 /* Hash Top */
+#define GEM_SA1B				0x0088 /* Specific1 Bottom */
+#define GEM_SA1T				0x008C /* Specific1 Top */
+#define GEM_SA2B				0x0090 /* Specific2 Bottom */
+#define GEM_SA2T				0x0094 /* Specific2 Top */
+#define GEM_SA3B				0x0098 /* Specific3 Bottom */
+#define GEM_SA3T				0x009C /* Specific3 Top */
+#define GEM_SA4B				0x00A0 /* Specific4 Bottom */
+#define GEM_SA4T				0x00A4 /* Specific4 Top */
+#define GEM_OTX					0x0100 /* Octets transmitted */
+#define GEM_DCFG1				0x0280 /* Design Config 1 */
+#define GEM_DCFG2				0x0284 /* Design Config 2 */
+#define GEM_DCFG3				0x0288 /* Design Config 3 */
+#define GEM_DCFG4				0x028c /* Design Config 4 */
+#define GEM_DCFG5				0x0290 /* Design Config 5 */
+#define GEM_DCFG6				0x0294 /* Design Config 6 */
+#define GEM_DCFG7				0x0298 /* Design Config 7 */
 
 #define GEM_ISR(hw_q)				(0x0400 + ((hw_q) << 2))
 #define GEM_TBQP(hw_q)				(0x0440 + ((hw_q) << 2))
@@ -98,179 +98,234 @@
 #define GEM_IMR(hw_q)				(0x0640 + ((hw_q) << 2))
 
 /* Bitfields in NCR */
-#define MACB_LB_OFFSET				0
+#define MACB_LB_OFFSET				0 /* reserved */
 #define MACB_LB_SIZE				1
-#define MACB_LLB_OFFSET				1
+#define MACB_LLB_OFFSET				1 /* Loop back local */
 #define MACB_LLB_SIZE				1
-#define MACB_RE_OFFSET				2
+#define MACB_RE_OFFSET				2 /* Receive enable */
 #define MACB_RE_SIZE				1
-#define MACB_TE_OFFSET				3
+#define MACB_TE_OFFSET				3 /* Transmit enable */
 #define MACB_TE_SIZE				1
-#define MACB_MPE_OFFSET				4
+#define MACB_MPE_OFFSET				4 /* Management port enable */
 #define MACB_MPE_SIZE				1
-#define MACB_CLRSTAT_OFFSET			5
+#define MACB_CLRSTAT_OFFSET			5 /* Clear stats regs */
 #define MACB_CLRSTAT_SIZE			1
-#define MACB_INCSTAT_OFFSET			6
+#define MACB_INCSTAT_OFFSET			6 /* Incremental stats regs */
 #define MACB_INCSTAT_SIZE			1
-#define MACB_WESTAT_OFFSET			7
+#define MACB_WESTAT_OFFSET			7 /* Write enable stats regs */
 #define MACB_WESTAT_SIZE			1
-#define MACB_BP_OFFSET				8
+#define MACB_BP_OFFSET				8 /* Back pressure */
 #define MACB_BP_SIZE				1
-#define MACB_TSTART_OFFSET			9
+#define MACB_TSTART_OFFSET			9 /* Start transmission */
 #define MACB_TSTART_SIZE			1
-#define MACB_THALT_OFFSET			10
+#define MACB_THALT_OFFSET			10 /* Transmit halt */
 #define MACB_THALT_SIZE				1
-#define MACB_NCR_TPF_OFFSET			11
+#define MACB_NCR_TPF_OFFSET			11 /* Transmit pause frame */
 #define MACB_NCR_TPF_SIZE			1
-#define MACB_TZQ_OFFSET				12
+#define MACB_TZQ_OFFSET				12 /* Transmit zero quantum
+						    * pause frame
+						    */
 #define MACB_TZQ_SIZE				1
 
 /* Bitfields in NCFGR */
-#define MACB_SPD_OFFSET				0
+#define MACB_SPD_OFFSET				0 /* Speed */
 #define MACB_SPD_SIZE				1
-#define MACB_FD_OFFSET				1
+#define MACB_FD_OFFSET				1 /* Full duplex */
 #define MACB_FD_SIZE				1
-#define MACB_BIT_RATE_OFFSET			2
+#define MACB_BIT_RATE_OFFSET			2 /* Discard non-VLAN frames */
 #define MACB_BIT_RATE_SIZE			1
-#define MACB_JFRAME_OFFSET			3
+#define MACB_JFRAME_OFFSET			3 /* reserved */
 #define MACB_JFRAME_SIZE			1
-#define MACB_CAF_OFFSET				4
+#define MACB_CAF_OFFSET				4 /* Copy all frames */
 #define MACB_CAF_SIZE				1
-#define MACB_NBC_OFFSET				5
+#define MACB_NBC_OFFSET				5 /* No broadcast */
 #define MACB_NBC_SIZE				1
-#define MACB_NCFGR_MTI_OFFSET			6
+#define MACB_NCFGR_MTI_OFFSET			6 /* Multicast hash enable */
 #define MACB_NCFGR_MTI_SIZE			1
-#define MACB_UNI_OFFSET				7
+#define MACB_UNI_OFFSET				7 /* Unicast hash enable */
 #define MACB_UNI_SIZE				1
-#define MACB_BIG_OFFSET				8
+#define MACB_BIG_OFFSET				8 /* Receive 1536 byte frames */
 #define MACB_BIG_SIZE				1
-#define MACB_EAE_OFFSET				9
+#define MACB_EAE_OFFSET				9 /* External address match
+						   * enable
+						   */
 #define MACB_EAE_SIZE				1
 #define MACB_CLK_OFFSET				10
 #define MACB_CLK_SIZE				2
-#define MACB_RTY_OFFSET				12
+#define MACB_RTY_OFFSET				12 /* Retry test */
 #define MACB_RTY_SIZE				1
-#define MACB_PAE_OFFSET				13
+#define MACB_PAE_OFFSET				13 /* Pause enable */
 #define MACB_PAE_SIZE				1
 #define MACB_RM9200_RMII_OFFSET			13 /* AT91RM9200 only */
 #define MACB_RM9200_RMII_SIZE			1  /* AT91RM9200 only */
-#define MACB_RBOF_OFFSET			14
+#define MACB_RBOF_OFFSET			14 /* Receive buffer offset */
 #define MACB_RBOF_SIZE				2
-#define MACB_RLCE_OFFSET			16
+#define MACB_RLCE_OFFSET			16 /* Length field error frame
+						    * discard
+						    */
 #define MACB_RLCE_SIZE				1
-#define MACB_DRFCS_OFFSET			17
+#define MACB_DRFCS_OFFSET			17 /* FCS remove */
 #define MACB_DRFCS_SIZE				1
 #define MACB_EFRHD_OFFSET			18
 #define MACB_EFRHD_SIZE				1
 #define MACB_IRXFCS_OFFSET			19
 #define MACB_IRXFCS_SIZE			1
 
 /* GEM specific NCFGR bitfields. */
-#define GEM_GBE_OFFSET				10
+#define GEM_GBE_OFFSET				10 /* Gigabit mode enable */
 #define GEM_GBE_SIZE				1
-#define GEM_CLK_OFFSET				18
+#define GEM_CLK_OFFSET				18 /* MDC clock division */
 #define GEM_CLK_SIZE				3
-#define GEM_DBW_OFFSET				21
+#define GEM_DBW_OFFSET				21 /* Data bus width */
 #define GEM_DBW_SIZE				2
 #define GEM_RXCOEN_OFFSET			24
 #define GEM_RXCOEN_SIZE				1
 
 /* Constants for data bus width. */
-#define GEM_DBW32				0
-#define GEM_DBW64				1
-#define GEM_DBW128				2
+#define GEM_DBW32				0 /* 32 bit AMBA AHB data bus
+						   * width
+						   */
+#define GEM_DBW64				1 /* 64 bit AMBA AHB data bus
+						   * width
+						   */
+#define GEM_DBW128				2 /* 128 bit AMBA AHB data bus
+						   * width
+						   */
 
 /* Bitfields in DMACFG. */
-#define GEM_FBLDO_OFFSET			0
+#define GEM_FBLDO_OFFSET			0 /* AHB fixed burst length for
+						   * DMA data operations
+						   */
 #define GEM_FBLDO_SIZE				5
-#define GEM_ENDIA_OFFSET			7
+#define GEM_ENDIA_OFFSET			7 /* AHB endian swap mode enable
+						   * for packet data accesses
+						   */
 #define GEM_ENDIA_SIZE				1
-#define GEM_RXBMS_OFFSET			8
+#define GEM_RXBMS_OFFSET			8 /* Receiver packet buffer
+						   * memory size select
+						   */
 #define GEM_RXBMS_SIZE				2
-#define GEM_TXPBMS_OFFSET			10
+#define GEM_TXPBMS_OFFSET			10 /* Transmitter packet buffer
+						    * memory size select
+						    */
 #define GEM_TXPBMS_SIZE				1
-#define GEM_TXCOEN_OFFSET			11
+#define GEM_TXCOEN_OFFSET			11 /* Transmitter IP, TCP and
+						    * UDP checksum generation
+						    * offload enable
+						    */
 #define GEM_TXCOEN_SIZE				1
-#define GEM_RXBS_OFFSET				16
+#define GEM_RXBS_OFFSET				16 /* DMA receive buffer size in
+						    * AHB system memory
+						    */
 #define GEM_RXBS_SIZE				8
-#define GEM_DDRP_OFFSET				24
+#define GEM_DDRP_OFFSET				24 /* disc_when_no_ahb */
 #define GEM_DDRP_SIZE				1
 
 
 /* Bitfields in NSR */
-#define MACB_NSR_LINK_OFFSET			0
+#define MACB_NSR_LINK_OFFSET			0 /* pcs_link_state */
 #define MACB_NSR_LINK_SIZE			1
-#define MACB_MDIO_OFFSET			1
+#define MACB_MDIO_OFFSET			1 /* status of the mdio_in
+						   * pin
+						   */
 #define MACB_MDIO_SIZE				1
-#define MACB_IDLE_OFFSET			2
+#define MACB_IDLE_OFFSET			2 /* The PHY management logic is
+						   * idle (i.e. has completed)
+						   */
 #define MACB_IDLE_SIZE				1
 
 /* Bitfields in TSR */
-#define MACB_UBR_OFFSET				0
+#define MACB_UBR_OFFSET				0 /* Used bit read */
 #define MACB_UBR_SIZE				1
-#define MACB_COL_OFFSET				1
+#define MACB_COL_OFFSET				1 /* Collision occurred */
 #define MACB_COL_SIZE				1
-#define MACB_TSR_RLE_OFFSET			2
+#define MACB_TSR_RLE_OFFSET			2 /* Retry limit exceeded */
 #define MACB_TSR_RLE_SIZE			1
-#define MACB_TGO_OFFSET				3
+#define MACB_TGO_OFFSET				3 /* Transmit go */
 #define MACB_TGO_SIZE				1
-#define MACB_BEX_OFFSET				4
+#define MACB_BEX_OFFSET				4 /* Transmit frame corruption
+						   * due to AHB error
+						   */
 #define MACB_BEX_SIZE				1
 #define MACB_RM9200_BNQ_OFFSET			4 /* AT91RM9200 only */
 #define MACB_RM9200_BNQ_SIZE			1 /* AT91RM9200 only */
-#define MACB_COMP_OFFSET			5
+#define MACB_COMP_OFFSET			5 /* Trnasmit complete */
 #define MACB_COMP_SIZE				1
-#define MACB_UND_OFFSET				6
+#define MACB_UND_OFFSET				6 /* Trnasmit under run */
 #define MACB_UND_SIZE				1
 
 /* Bitfields in RSR */
-#define MACB_BNA_OFFSET				0
+#define MACB_BNA_OFFSET				0 /* Buffer not available */
 #define MACB_BNA_SIZE				1
-#define MACB_REC_OFFSET				1
+#define MACB_REC_OFFSET				1 /* Frame received */
 #define MACB_REC_SIZE				1
-#define MACB_OVR_OFFSET				2
+#define MACB_OVR_OFFSET				2 /* Receive overrun */
 #define MACB_OVR_SIZE				1
 
 /* Bitfields in ISR/IER/IDR/IMR */
-#define MACB_MFD_OFFSET				0
+#define MACB_MFD_OFFSET				0 /* Management frame sent */
 #define MACB_MFD_SIZE				1
-#define MACB_RCOMP_OFFSET			1
+#define MACB_RCOMP_OFFSET			1 /* Receive complete */
 #define MACB_RCOMP_SIZE				1
-#define MACB_RXUBR_OFFSET			2
+#define MACB_RXUBR_OFFSET			2 /* RX used bit read */
 #define MACB_RXUBR_SIZE				1
-#define MACB_TXUBR_OFFSET			3
+#define MACB_TXUBR_OFFSET			3 /* TX used bit read */
 #define MACB_TXUBR_SIZE				1
-#define MACB_ISR_TUND_OFFSET			4
+#define MACB_ISR_TUND_OFFSET			4 /* Enable trnasmit buffer
+						   * under run interrupt
+						   */
 #define MACB_ISR_TUND_SIZE			1
-#define MACB_ISR_RLE_OFFSET			5
+#define MACB_ISR_RLE_OFFSET			5 /* Enable retry limit exceeded
+						   * or late collision interrupt
+						   */
 #define MACB_ISR_RLE_SIZE			1
-#define MACB_TXERR_OFFSET			6
+#define MACB_TXERR_OFFSET			6 /* Enable transmit frame
+						   * corruption due to AHB error
+						   * interrupt
+						   */
 #define MACB_TXERR_SIZE				1
-#define MACB_TCOMP_OFFSET			7
+#define MACB_TCOMP_OFFSET			7 /* Enable transmit complete
+						   * interrupt
+						   */
 #define MACB_TCOMP_SIZE				1
-#define MACB_ISR_LINK_OFFSET			9
+#define MACB_ISR_LINK_OFFSET			9 /* Enable link change
+						   * interrupt
+						   */
 #define MACB_ISR_LINK_SIZE			1
-#define MACB_ISR_ROVR_OFFSET			10
+#define MACB_ISR_ROVR_OFFSET			10 /* Enable receive overrun
+						    * interrupt
+						    */
 #define MACB_ISR_ROVR_SIZE			1
-#define MACB_HRESP_OFFSET			11
+#define MACB_HRESP_OFFSET			11 /* Enable hrsep not OK
+						    * interrupt
+						    */
 #define MACB_HRESP_SIZE				1
-#define MACB_PFR_OFFSET				12
+#define MACB_PFR_OFFSET				12 /* Enable pause frame with
+						    * non-zero pause quantum
+						    * interrupt
+						    */
 #define MACB_PFR_SIZE				1
-#define MACB_PTZ_OFFSET				13
+#define MACB_PTZ_OFFSET				13 /* Enable pause time zero
+						    * interrupt
+						    */
 #define MACB_PTZ_SIZE				1
 
 /* Bitfields in MAN */
-#define MACB_DATA_OFFSET			0
+#define MACB_DATA_OFFSET			0 /* data */
 #define MACB_DATA_SIZE				16
-#define MACB_CODE_OFFSET			16
+#define MACB_CODE_OFFSET			16 /* Must be written to 10 */
 #define MACB_CODE_SIZE				2
-#define MACB_REGA_OFFSET			18
+#define MACB_REGA_OFFSET			18 /* Register address */
 #define MACB_REGA_SIZE				5
-#define MACB_PHYA_OFFSET			23
+#define MACB_PHYA_OFFSET			23 /* PHY address */
 #define MACB_PHYA_SIZE				5
-#define MACB_RW_OFFSET				28
+#define MACB_RW_OFFSET				28 /* Operation. 10 is read. 01
+						    * is write.
+						    */
 #define MACB_RW_SIZE				2
-#define MACB_SOF_OFFSET				30
+#define MACB_SOF_OFFSET				30 /* Must be written to 1 for
+						    * Clause 22 operation
+						    */
 #define MACB_SOF_SIZE				2
 
 /* Bitfields in USRIO (AVR32) */
@@ -286,7 +341,7 @@
 /* Bitfields in USRIO (AT91) */
 #define MACB_RMII_OFFSET			0
 #define MACB_RMII_SIZE				1
-#define GEM_RGMII_OFFSET			0	/* GEM gigabit mode */
+#define GEM_RGMII_OFFSET			0 /* GEM gigabit mode */
 #define GEM_RGMII_SIZE				1
 #define MACB_CLKEN_OFFSET			1
 #define MACB_CLKEN_SIZE				1