ath9k_hw: Add a function to read sqsum_dvc.

Add a function to observe the delta VC of BB_PLL.
For a good chip, the sqsum_dvc is below 2000.

Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 48d121c24eb..0e64d766605 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -668,6 +668,19 @@ static void ath9k_hw_init_qos(struct ath_hw *ah)
         REGWRITE_BUFFER_FLUSH(ah);
 }
 
+unsigned long ar9003_get_pll_sqsum_dvc(struct ath_hw *ah)
+{
+                REG_WRITE(ah, PLL3, (REG_READ(ah, PLL3) & ~(PLL3_DO_MEAS_MASK)));
+                udelay(100);
+                REG_WRITE(ah, PLL3, (REG_READ(ah, PLL3) | PLL3_DO_MEAS_MASK));
+
+                while ((REG_READ(ah, PLL4) & PLL4_MEAS_DONE) == 0)
+                        udelay(100);
+
+                return (REG_READ(ah, PLL3) & SQSUM_DVC_MASK) >> 3;
+}
+EXPORT_SYMBOL(ar9003_get_pll_sqsum_dvc);
+
 static void ath9k_hw_init_pll(struct ath_hw *ah,
                               struct ath9k_channel *chan)
 {