kernel: mac80211: add pending ath9k EEPROM swapping patches

There are two types of swapping the EEPROM data in the ath9k driver.
Before this series one type of swapping could not be used without the
other.

The first type of swapping looks at the "magic bytes" at the start of
the EEPROM data and performs swab16 on the EEPROM contents if needed.
The second type of swapping is EEPROM format specific and swaps
specific fields within the EEPROM itself (swab16, swab32 - depends on
the EEPROM format).

With this series the second part now looks at the EEPMISC register
inside the EEPROM, which uses a bit to indicate if the EEPROM data
is Big Endian (this is also done by the FreeBSD kernel).
This has a nice advantage: currently there are some out-of-tree hacks
(in OpenWrt and LEDE) where the EEPROM has a Big Endian header on a
Big Endian system (= no swab16 is performed) but the EEPROM itself
indicates that it's data is Little Endian. Until now the out-of-tree
code simply did a swab16 before passing the data to ath9k, so ath9k
first did the swab16 - this also enabled the format specific swapping.
These out-of-tree hacks are still working with the new logic, but it
is recommended to remove them. This implementation is based on a
discussion with Arnd Bergmann who raised concerns about the
robustness and portability of the swapping logic in the original OF
support patch review, see [0].

After a second round of patches (= v1 of this series) neither Arnd
Bergmann nor I were really happy with the complexity of the EEPROM
swapping logic. Based on a discussion (see [1] and [2]) we decided
that ath9k should use a defined format (specifying the endianness
of the data - I went with __le16 and __le32) when accessing the
EEPROM fields. A benefit of this is that we enable the EEPMISC based
swapping logic by default, just like the FreeBSD driver, see [3]. On
the devices which I have tested (see below) ath9k now works without
having to specify the "endian_check" field in ath9k_platform_data (or
a similar logic which could provide this via devicetree) as ath9k now
detects the endianness automatically. Only EEPROMs which are mangled
by some out-of-tree code still need the endian_check flag (or one can
simply remove that mangling from the out-of-tree code).

[0] http://www.spinics.net/lists/linux-wireless/msg152634.html
[1] https://marc.info/?l=linux-wireless&m=147250597503174&w=2
[2] https://marc.info/?l=linux-wireless&m=147254388611344&w=2
[3] https://github.com/freebsd/freebsd/blob/50719b56d9ce8d7d4beb53b16e9edb2e9a4a7a18/sys/dev/ath/ath_hal/ah_eeprom_9287.c#L351

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

1 files changed, 95 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/550-ath9k-Add-a-define-for-the-EEPROM-eepmisc-endianness.patch b/package/kernel/mac80211/patches/550-ath9k-Add-a-define-for-the-EEPROM-eepmisc-endianness.patch
new file mode 100644
index 0000000000..a17f95682f
--- /dev/null
+++ b/package/kernel/mac80211/patches/550-ath9k-Add-a-define-for-the-EEPROM-eepmisc-endianness.patch
@@ -0,0 +1,95 @@
+From 9692ab1ff30ae0abc1000d11b2f929b6e2e4cb7f Mon Sep 17 00:00:00 2001
+From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+Date: Mon, 3 Oct 2016 00:29:07 +0200
+Subject: [v2 PATCH 1/7] ath9k: Add a #define for the EEPROM "eepmisc" endianness
+ bit
+
+This replaces a magic number with a named #define. Additionally it
+removes two "eeprom format" specific #defines for the "big endianness"
+bit which are the same on all eeprom formats.
+
+Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+---
+ drivers/net/wireless/ath/ath9k/ar9003_eeprom.c | 3 ++-
+ drivers/net/wireless/ath/ath9k/ar9003_eeprom.h | 1 -
+ drivers/net/wireless/ath/ath9k/eeprom.h        | 4 +++-
+ drivers/net/wireless/ath/ath9k/eeprom_4k.c     | 2 +-
+ drivers/net/wireless/ath/ath9k/eeprom_9287.c   | 2 +-
+ drivers/net/wireless/ath/ath9k/eeprom_def.c    | 2 +-
+ 6 files changed, 8 insertions(+), 6 deletions(-)
+
+--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
++++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
+@@ -3468,7 +3468,8 @@ static u32 ath9k_hw_ar9003_dump_eeprom(s
+ 					AR5416_OPFLAGS_N_5G_HT20));
+ 	PR_EEP("Disable 5Ghz HT40", !!(pBase->opCapFlags.opFlags &
+ 					AR5416_OPFLAGS_N_5G_HT40));
+-	PR_EEP("Big Endian", !!(pBase->opCapFlags.eepMisc & 0x01));
++	PR_EEP("Big Endian", !!(pBase->opCapFlags.eepMisc &
++				AR5416_EEPMISC_BIG_ENDIAN));
+ 	PR_EEP("RF Silent", pBase->rfSilent);
+ 	PR_EEP("BT option", pBase->blueToothOptions);
+ 	PR_EEP("Device Cap", pBase->deviceCap);
+--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.h
++++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.h
+@@ -38,7 +38,6 @@
+ #define AR9300_NUM_CTLS_2G           12
+ #define AR9300_NUM_BAND_EDGES_5G     8
+ #define AR9300_NUM_BAND_EDGES_2G     4
+-#define AR9300_EEPMISC_BIG_ENDIAN    0x01
+ #define AR9300_EEPMISC_WOW           0x02
+ #define AR9300_CUSTOMER_DATA_SIZE    20
+ 
+--- a/drivers/net/wireless/ath/ath9k/eeprom.h
++++ b/drivers/net/wireless/ath/ath9k/eeprom.h
+@@ -161,6 +161,9 @@
+ #define AR5416_EEP_TXGAIN_ORIGINAL         0
+ #define AR5416_EEP_TXGAIN_HIGH_POWER       1
+ 
++/* Endianness of EEPROM content */
++#define AR5416_EEPMISC_BIG_ENDIAN          0x01
++
+ #define AR5416_EEP4K_START_LOC                64
+ #define AR5416_EEP4K_NUM_2G_CAL_PIERS         3
+ #define AR5416_EEP4K_NUM_2G_CCK_TARGET_POWERS 3
+@@ -191,7 +194,6 @@
+ #define AR9287_NUM_CTLS              	12
+ #define AR9287_NUM_BAND_EDGES        	4
+ #define AR9287_PD_GAIN_ICEPTS           1
+-#define AR9287_EEPMISC_BIG_ENDIAN       0x01
+ #define AR9287_EEPMISC_WOW              0x02
+ #define AR9287_MAX_CHAINS               2
+ #define AR9287_ANT_16S                  32
+--- a/drivers/net/wireless/ath/ath9k/eeprom_4k.c
++++ b/drivers/net/wireless/ath/ath9k/eeprom_4k.c
+@@ -154,7 +154,7 @@ static u32 ath9k_hw_4k_dump_eeprom(struc
+ 					AR5416_OPFLAGS_N_5G_HT20));
+ 	PR_EEP("Disable 5Ghz HT40", !!(pBase->opCapFlags &
+ 					AR5416_OPFLAGS_N_5G_HT40));
+-	PR_EEP("Big Endian", !!(pBase->eepMisc & 0x01));
++	PR_EEP("Big Endian", !!(pBase->eepMisc & AR5416_EEPMISC_BIG_ENDIAN));
+ 	PR_EEP("Cal Bin Major Ver", (pBase->binBuildNumber >> 24) & 0xFF);
+ 	PR_EEP("Cal Bin Minor Ver", (pBase->binBuildNumber >> 16) & 0xFF);
+ 	PR_EEP("Cal Bin Build", (pBase->binBuildNumber >> 8) & 0xFF);
+--- a/drivers/net/wireless/ath/ath9k/eeprom_9287.c
++++ b/drivers/net/wireless/ath/ath9k/eeprom_9287.c
+@@ -150,7 +150,7 @@ static u32 ath9k_hw_ar9287_dump_eeprom(s
+ 					AR5416_OPFLAGS_N_5G_HT20));
+ 	PR_EEP("Disable 5Ghz HT40", !!(pBase->opCapFlags &
+ 					AR5416_OPFLAGS_N_5G_HT40));
+-	PR_EEP("Big Endian", !!(pBase->eepMisc & 0x01));
++	PR_EEP("Big Endian", !!(pBase->eepMisc & AR5416_EEPMISC_BIG_ENDIAN));
+ 	PR_EEP("Cal Bin Major Ver", (pBase->binBuildNumber >> 24) & 0xFF);
+ 	PR_EEP("Cal Bin Minor Ver", (pBase->binBuildNumber >> 16) & 0xFF);
+ 	PR_EEP("Cal Bin Build", (pBase->binBuildNumber >> 8) & 0xFF);
+--- a/drivers/net/wireless/ath/ath9k/eeprom_def.c
++++ b/drivers/net/wireless/ath/ath9k/eeprom_def.c
+@@ -232,7 +232,7 @@ static u32 ath9k_hw_def_dump_eeprom(stru
+ 					AR5416_OPFLAGS_N_5G_HT20));
+ 	PR_EEP("Disable 5Ghz HT40", !!(pBase->opCapFlags &
+ 					AR5416_OPFLAGS_N_5G_HT40));
+-	PR_EEP("Big Endian", !!(pBase->eepMisc & 0x01));
++	PR_EEP("Big Endian", !!(pBase->eepMisc & AR5416_EEPMISC_BIG_ENDIAN));
+ 	PR_EEP("Cal Bin Major Ver", (pBase->binBuildNumber >> 24) & 0xFF);
+ 	PR_EEP("Cal Bin Minor Ver", (pBase->binBuildNumber >> 16) & 0xFF);
+ 	PR_EEP("Cal Bin Build", (pBase->binBuildNumber >> 8) & 0xFF);