ath9k: define all EEPROM fields in Little Endian format

The ar9300_eeprom logic is already using only 8-bit (endian neutral),
__le16 and __le32 fields to state explicitly how the values should be
interpreted.
All other EEPROM implementations (4k, 9287 and def) were using u16 and
u32 fields with additional logic to swap the values (read from the
original EEPROM) so they match the current CPUs endianness.

The EEPROM format defaults to "all values are Little Endian", indicated
by the absence of the AR5416_EEPMISC_BIG_ENDIAN in the u8 EEPMISC
register. If we detect that the EEPROM indicates Big Endian mode
(AR5416_EEPMISC_BIG_ENDIAN is set in the EEPMISC register) then we'll
swap the values to convert them into Little Endian. This is done by
activating the EEPMISC based logic in ath9k_hw_nvram_swap_data even if
AH_NO_EEP_SWAP is set (this makes ath9k behave like the FreeBSD driver,
which also does not have a flag to enable swapping based on the
AR5416_EEPMISC_BIG_ENDIAN bit). Before this logic was only used to
enable swapping when "current CPU endianness != EEPROM endianness".

After changing all relevant fields to __le16 and __le32 sparse was used
to check that all code which reads any of these fields uses
le{16,32}_to_cpu.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 6 insertions, 21 deletions

diff --git a/drivers/net/wireless/ath/ath9k/eeprom.c b/drivers/net/wireless/ath/ath9k/eeprom.c
index 0e46797601be..fb80ec86e53d 100644
--- a/drivers/net/wireless/ath/ath9k/eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/eeprom.c
@@ -155,17 +155,10 @@ bool ath9k_hw_nvram_read(struct ath_hw *ah, u32 off, u16 *data)
 	return ret;
 }
 
-#ifdef __BIG_ENDIAN
-#define EXPECTED_EEPMISC_ENDIAN AR5416_EEPMISC_BIG_ENDIAN
-#else
-#define EXPECTED_EEPMISC_ENDIAN 0
-#endif
-
 int ath9k_hw_nvram_swap_data(struct ath_hw *ah, bool *swap_needed, int size)
 {
 	u16 magic;
 	u16 *eepdata;
-	u8 eepmisc;
 	int i;
 	bool needs_byteswap = false;
 	struct ath_common *common = ath9k_hw_common(ah);
@@ -203,25 +196,17 @@ int ath9k_hw_nvram_swap_data(struct ath_hw *ah, bool *swap_needed, int size)
 		}
 	}
 
-	*swap_needed = false;
-
-	eepmisc = ah->eep_ops->get_eepmisc(ah);
-	if ((eepmisc & AR5416_EEPMISC_BIG_ENDIAN) != EXPECTED_EEPMISC_ENDIAN) {
-		if (ah->ah_flags & AH_NO_EEP_SWAP) {
-			ath_info(common,
-				 "Ignoring endianness difference in eepmisc register.\n");
-		} else {
-			*swap_needed = true;
-			ath_dbg(common, EEPROM,
-				"EEPROM needs swapping according to the eepmisc register.\n");
-		}
+	if (ah->eep_ops->get_eepmisc(ah) & AR5416_EEPMISC_BIG_ENDIAN) {
+		*swap_needed = true;
+		ath_dbg(common, EEPROM,
+			"Big Endian EEPROM detected according to EEPMISC register.\n");
+	} else {
+		*swap_needed = false;
 	}
 
 	return 0;
 }
 
-#undef EXPECTED_EEPMISC_VAL
-
 bool ath9k_hw_nvram_validate_checksum(struct ath_hw *ah, int size)
 {
 	u32 i, sum = 0;