net: ipa: clarify endpoint register macro constraints

A handful of registers are valid only for RX endpoints, and some
others are valid only for TX endpoints.  For these endpoints, add
a comment above their defined offset macro that indicates the
endpoints to which they apply.

Extend the endpoint parameter naming convention as well, to make
these constraints more explicit.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ipa/ipa_reg.h

@@ -32,10 +32,12 @@ struct ipa;
  * parameter is supplied to the offset macro.  The "ee" value is a member of
  * the gsi_ee enumerated type.
  *
- * The offset of a register dependent on endpoint id is computed by a macro
- * that is supplied a parameter "ep".  The "ep" value is assumed to be less
- * than the maximum endpoint value for the current hardware, and that will
- * not exceed IPA_ENDPOINT_MAX.
+ * The offset of a register dependent on endpoint ID is computed by a macro
+ * that is supplied a parameter "ep", "txep", or "rxep".  A register with an
+ * "ep" parameter is valid for any endpoint; a register with a "txep" or
+ * "rxep" parameter is valid only for TX or RX endpoints, respectively.  The
+ * "*ep" value is assumed to be less than the maximum valid endpoint ID
+ * for the current hardware, and that will not exceed IPA_ENDPOINT_MAX.
  *
  * The offset of registers related to filter and route tables is computed
  * by a macro that is supplied a parameter "er".  The "er" represents an
@@ -292,11 +294,13 @@ static inline u32 ipa_reg_idle_indication_cfg_offset(enum ipa_version version)
 #define HDR_TOTAL_LEN_OR_PAD_OFFSET_FMASK	GENMASK(9, 4)
 #define HDR_PAD_TO_ALIGNMENT_FMASK		GENMASK(13, 10)
 
-#define IPA_REG_ENDP_INIT_HDR_METADATA_MASK_N_OFFSET(ep) \
-					(0x00000818 + 0x0070 * (ep))
+/* Valid only for RX (IPA producer) endpoints */
+#define IPA_REG_ENDP_INIT_HDR_METADATA_MASK_N_OFFSET(rxep) \
+					(0x00000818 + 0x0070 * (rxep))
 
-#define IPA_REG_ENDP_INIT_MODE_N_OFFSET(ep) \
-					(0x00000820 + 0x0070 * (ep))
+/* Valid only for TX (IPA consumer) endpoints */
+#define IPA_REG_ENDP_INIT_MODE_N_OFFSET(txep) \
+					(0x00000820 + 0x0070 * (txep))
 #define MODE_FMASK				GENMASK(2, 0)
 #define DEST_PIPE_INDEX_FMASK			GENMASK(8, 4)
 #define BYTE_THRESHOLD_FMASK			GENMASK(27, 12)
@@ -315,19 +319,21 @@ static inline u32 ipa_reg_idle_indication_cfg_offset(enum ipa_version version)
 #define AGGR_FORCE_CLOSE_FMASK			GENMASK(22, 22)
 #define AGGR_HARD_BYTE_LIMIT_ENABLE_FMASK	GENMASK(24, 24)
 
-#define IPA_REG_ENDP_INIT_HOL_BLOCK_EN_N_OFFSET(ep) \
-					(0x0000082c +  0x0070 * (ep))
+/* Valid only for RX (IPA producer) endpoints */
+#define IPA_REG_ENDP_INIT_HOL_BLOCK_EN_N_OFFSET(rxep) \
+					(0x0000082c +  0x0070 * (rxep))
 #define HOL_BLOCK_EN_FMASK			GENMASK(0, 0)
 
-/* The next register is valid only for RX (IPA producer) endpoints */
-#define IPA_REG_ENDP_INIT_HOL_BLOCK_TIMER_N_OFFSET(ep) \
-					(0x00000830 +  0x0070 * (ep))
+/* Valid only for RX (IPA producer) endpoints */
+#define IPA_REG_ENDP_INIT_HOL_BLOCK_TIMER_N_OFFSET(rxep) \
+					(0x00000830 +  0x0070 * (rxep))
 /* The next fields are present for IPA v4.2 only */
 #define BASE_VALUE_FMASK			GENMASK(4, 0)
 #define SCALE_FMASK				GENMASK(12, 8)
 
-#define IPA_REG_ENDP_INIT_DEAGGR_N_OFFSET(ep) \
-					(0x00000834 + 0x0070 * (ep))
+/* Valid only for TX (IPA consumer) endpoints */
+#define IPA_REG_ENDP_INIT_DEAGGR_N_OFFSET(txep) \
+					(0x00000834 + 0x0070 * (txep))
 #define DEAGGR_HDR_LEN_FMASK			GENMASK(5, 0)
 #define PACKET_OFFSET_VALID_FMASK		GENMASK(7, 7)
 #define PACKET_OFFSET_LOCATION_FMASK		GENMASK(13, 8)
@@ -337,8 +343,9 @@ static inline u32 ipa_reg_idle_indication_cfg_offset(enum ipa_version version)
 					(0x00000838 + 0x0070 * (ep))
 #define RSRC_GRP_FMASK				GENMASK(1, 0)
 
-#define IPA_REG_ENDP_INIT_SEQ_N_OFFSET(ep) \
-					(0x0000083c + 0x0070 * (ep))
+/* Valid only for TX (IPA consumer) endpoints */
+#define IPA_REG_ENDP_INIT_SEQ_N_OFFSET(txep) \
+					(0x0000083c + 0x0070 * (txep))
 #define HPS_SEQ_TYPE_FMASK			GENMASK(3, 0)
 #define DPS_SEQ_TYPE_FMASK			GENMASK(7, 4)
 #define HPS_REP_SEQ_TYPE_FMASK			GENMASK(11, 8)
@@ -352,7 +359,7 @@ static inline u32 ipa_reg_idle_indication_cfg_offset(enum ipa_version version)
 /* The next field is present for IPA v4.0 and above */
 #define STATUS_PKT_SUPPRESS_FMASK		GENMASK(9, 9)
 
-/* "er" is either an endpoint id (for filters) or a route id (for routes) */
+/* "er" is either an endpoint ID (for filters) or a route ID (for routes) */
 #define IPA_REG_ENDP_FILTER_ROUTER_HSH_CFG_N_OFFSET(er) \
 					(0x0000085c + 0x0070 * (er))
 #define FILTER_HASH_MSK_SRC_ID_FMASK		GENMASK(0, 0)