We adjust the core clock for ar9271 to 117 MHz; this also
requires us to adjust the baud divider based on the targetted
baud rate.
Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/hw.c | 36 ++++++++++++++++++++++++++++++++++
drivers/net/wireless/ath/ath9k/reg.h | 3 ++
2 files changed, 39 insertions(+), 0 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 6df00ab..f67d3a4 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1040,6 +1040,22 @@ static void ath9k_hw_init_qos(struct ath_hw *ah)
REG_WRITE(ah, AR_TXOP_12_15, 0xFFFFFFFF);
}
+static void ath9k_hw_change_target_baud(struct ath_hw *ah, u32 freq, u32 baud)
+{
+ u32 lcr;
+ u32 baud_divider = freq * 1000 * 1000 / 16 / baud;
+
+ lcr = REG_READ(ah , 0x5100c);
+ lcr |= 0x80;
+
+ REG_WRITE(ah, 0x5100c, lcr);
+ REG_WRITE(ah, 0x51004, (baud_divider >> 8));
+ REG_WRITE(ah, 0x51000, (baud_divider & 0xff));
+
+ lcr &= ~0x80;
+ REG_WRITE(ah, 0x5100c, lcr);
+}
+
static void ath9k_hw_init_pll(struct ath_hw *ah,
struct ath9k_channel *chan)
{
@@ -1103,6 +1119,26 @@ static void ath9k_hw_init_pll(struct ath_hw *ah,
}
REG_WRITE(ah, AR_RTC_PLL_CONTROL, pll);
+ /* Switch the core clock for ar9271 to 117Mhz */
+ if (AR_SREV_9271(ah)) {
+ if ((pll == 0x142c) || (pll == 0x2850) ) {
+ udelay(500);
+ /* set CLKOBS to output AHB clock */
+ REG_WRITE(ah, 0x7020, 0xe);
+ /*
+ * 0x304: 117Mhz, ahb_ratio: 1x1
+ * 0x306: 40Mhz, ahb_ratio: 1x1
+ */
+ REG_WRITE(ah, 0x50040, 0x304);
+ /*
+ * makes adjustments for the baud dividor to keep the
+ * targetted baud rate based on the used core clock.
+ */
+ ath9k_hw_change_target_baud(ah, AR9271_CORE_CLOCK,
+ AR9271_TARGET_BAUD_RATE);
+ }
+ }
+
udelay(RTC_PLL_SETTLE_DELAY);
REG_WRITE(ah, AR_RTC_SLEEP_CLK, AR_RTC_FORCE_DERIVED_CLK);
diff --git a/drivers/net/wireless/ath/ath9k/reg.h b/drivers/net/wireless/ath/ath9k/reg.h
index ceed009..061e12c 100644
--- a/drivers/net/wireless/ath/ath9k/reg.h
+++ b/drivers/net/wireless/ath/ath9k/reg.h
@@ -1704,4 +1704,7 @@ enum {
#define AR_KEYTABLE_MAC0(_n) (AR_KEYTABLE(_n) + 24)
#define AR_KEYTABLE_MAC1(_n) (AR_KEYTABLE(_n) + 28)
+#define AR9271_CORE_CLOCK 117 /* clock to 117Mhz */
+#define AR9271_TARGET_BAUD_RATE 19200 /* 115200 */
+
#endif
--
1.6.0.4
--
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