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[1/3] net: dsa: mt7530: fix enabling EEE on MT7531 switch on all boards

Message ID 20240318-for-net-mt7530-fix-eee-for-mt7531-mt7988-v1-1-3f17226344e8@arinc9.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Fix EEE support for MT7531 and MT7988 SoC switch | expand

Checks

Context Check Description
netdev/series_format warning Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 939 this patch: 939
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 16 of 16 maintainers
netdev/build_clang success Errors and warnings before: 956 this patch: 956
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 956 this patch: 956
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 20 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-03-19--18-00 (tests: 907)

Commit Message

Arınç ÜNAL via B4 Relay March 18, 2024, 7:46 a.m. UTC 
From: Arınç ÜNAL <arinc.unal@arinc9.com>

The commit 40b5d2f15c09 ("net: dsa: mt7530: Add support for EEE features")
brought EEE support but did not enable EEE on MT7531 switch MACs. EEE is
enabled on MT7531 switch MACs either by pulling the LAN2LED0 pin low on the
board (bootstrapping), or unsetting the EEE_DIS bit on the trap register.

There are existing boards that were not designed to pull the pin low.
Therefore, unset the EEE_DIS bit on the trap register.

Unlike MT7530, the modifiable trap register won't be populated identical to
the trap status register after reset. Therefore, read from the trap status
register, modify the bits, then write to the modifiable trap register.

The disable EEE bit on the trap pertains to the LAN2LED0 pin which is
usually used to control an LED. Once the bit is unset, the pin will be low.
That will make the active low LED turn on.

The pin is controlled by the switch PHY. It seems that the PHY controls the
pin in the way that it inverts the pin state. That means depending on the
wiring of the LED connected to LAN2LED0 on the board, the LED may be on
without an active link.

Fixes: 40b5d2f15c09 ("net: dsa: mt7530: Add support for EEE features")
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
---
 drivers/net/dsa/mt7530.c | 7 +++++++
 drivers/net/dsa/mt7530.h | 1 +
 2 files changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 678b51f9cea6..d741d03969eb 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2458,6 +2458,13 @@  mt7531_setup(struct dsa_switch *ds)
 	/* Reset the switch through internal reset */
 	mt7530_write(priv, MT7530_SYS_CTRL, SYS_CTRL_SW_RST | SYS_CTRL_REG_RST);
 
+	/* Allow modifying the trap and enable Energy-Efficient Ethernet (EEE).
+	 */
+	val = mt7530_read(priv, MT7531_HWTRAP);
+	val |= CHG_STRAP;
+	val &= ~EEE_DIS;
+	mt7530_write(priv, MT7530_MHWTRAP, val);
+
 	if (!priv->p5_sgmii) {
 		mt7531_pll_setup(priv);
 	} else {
diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h
index a71166e0a7fc..509ed5362236 100644
--- a/drivers/net/dsa/mt7530.h
+++ b/drivers/net/dsa/mt7530.h
@@ -457,6 +457,7 @@  enum mt7531_clk_skew {
 #define  XTAL_FSEL_M			BIT(7)
 #define  PHY_EN				BIT(6)
 #define  CHG_STRAP			BIT(8)
+#define  EEE_DIS			BIT(4)
 
 /* Register for hw trap modification */
 #define MT7530_MHWTRAP			0x7804