From 24c1a280c8db6beddbb62662c30b79cd3c8d4d01 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Tue, 10 Feb 2009 15:35:22 -0800 Subject: [PATCH] ath9k: add comments for ath9k_hw_configpcipowersave() This is used for ASPM. Signed-off-by: Luis R. Rodriguez Signed-off-by: John W. Linville --- drivers/net/wireless/ath9k/hw.c | 35 +++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/net/wireless/ath9k/hw.c b/drivers/net/wireless/ath9k/hw.c index 72ca1c8ff09..cfcaaf886d0 100644 --- a/drivers/net/wireless/ath9k/hw.c +++ b/drivers/net/wireless/ath9k/hw.c @@ -2632,6 +2632,15 @@ bool ath9k_hw_setpower(struct ath_hw *ah, enum ath9k_power_mode mode) return status; } +/* + * Helper for ASPM support. + * + * Disable PLL when in L0s as well as receiver clock when in L1. + * This power saving option must be enabled through the SerDes. + * + * Programming the SerDes must go through the same 288 bit serial shift + * register as the other analog registers. Hence the 9 writes. + */ void ath9k_hw_configpcipowersave(struct ath_hw *ah, int restore) { u8 i; @@ -2639,13 +2648,20 @@ void ath9k_hw_configpcipowersave(struct ath_hw *ah, int restore) if (ah->is_pciexpress != true) return; + /* Do not touch SerDes registers */ if (ah->config.pcie_powersave_enable == 2) return; + /* Nothing to do on restore for 11N */ if (restore) return; if (AR_SREV_9280_20_OR_LATER(ah)) { + /* + * AR9280 2.0 or later chips use SerDes values from the + * initvals.h initialized depending on chipset during + * ath9k_hw_do_attach() + */ for (i = 0; i < ah->iniPcieSerdes.ia_rows; i++) { REG_WRITE(ah, INI_RA(&ah->iniPcieSerdes, i, 0), INI_RA(&ah->iniPcieSerdes, i, 1)); @@ -2656,10 +2672,12 @@ void ath9k_hw_configpcipowersave(struct ath_hw *ah, int restore) REG_WRITE(ah, AR_PCIE_SERDES, 0x9248fd00); REG_WRITE(ah, AR_PCIE_SERDES, 0x24924924); + /* RX shut off when elecidle is asserted */ REG_WRITE(ah, AR_PCIE_SERDES, 0xa8000019); REG_WRITE(ah, AR_PCIE_SERDES, 0x13160820); REG_WRITE(ah, AR_PCIE_SERDES, 0xe5980560); + /* Shut off CLKREQ active in L1 */ if (ah->config.pcie_clock_req) REG_WRITE(ah, AR_PCIE_SERDES, 0x401deffc); else @@ -2669,29 +2687,46 @@ void ath9k_hw_configpcipowersave(struct ath_hw *ah, int restore) REG_WRITE(ah, AR_PCIE_SERDES, 0xbe105554); REG_WRITE(ah, AR_PCIE_SERDES, 0x00043007); + /* Load the new settings */ REG_WRITE(ah, AR_PCIE_SERDES2, 0x00000000); udelay(1000); } else { REG_WRITE(ah, AR_PCIE_SERDES, 0x9248fc00); REG_WRITE(ah, AR_PCIE_SERDES, 0x24924924); + + /* RX shut off when elecidle is asserted */ REG_WRITE(ah, AR_PCIE_SERDES, 0x28000039); REG_WRITE(ah, AR_PCIE_SERDES, 0x53160824); REG_WRITE(ah, AR_PCIE_SERDES, 0xe5980579); + + /* + * Ignore ah->ah_config.pcie_clock_req setting for + * pre-AR9280 11n + */ REG_WRITE(ah, AR_PCIE_SERDES, 0x001defff); + REG_WRITE(ah, AR_PCIE_SERDES, 0x1aaabe40); REG_WRITE(ah, AR_PCIE_SERDES, 0xbe105554); REG_WRITE(ah, AR_PCIE_SERDES, 0x000e3007); + + /* Load the new settings */ REG_WRITE(ah, AR_PCIE_SERDES2, 0x00000000); } + /* set bit 19 to allow forcing of pcie core into L1 state */ REG_SET_BIT(ah, AR_PCIE_PM_CTRL, AR_PCIE_PM_CTRL_ENA); + /* Several PCIe massages to ensure proper behaviour */ if (ah->config.pcie_waen) { REG_WRITE(ah, AR_WA, ah->config.pcie_waen); } else { if (AR_SREV_9285(ah)) REG_WRITE(ah, AR_WA, AR9285_WA_DEFAULT); + /* + * On AR9280 chips bit 22 of 0x4004 needs to be set to + * otherwise card may disappear. + */ else if (AR_SREV_9280(ah)) REG_WRITE(ah, AR_WA, AR9280_WA_DEFAULT); else -- 2.20.1