1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/net/wireless/b43/phy_common.c b/drivers/net/wireless/b43/phy_common.c
index 75b26e175e8f..8f7d7eff2d80 100644
--- a/drivers/net/wireless/b43/phy_common.c
+++ b/drivers/net/wireless/b43/phy_common.c
@@ -421,3 +421,48 @@ void b43_phyop_switch_analog_generic(struct b43_wldev *dev, bool on)
 {
         b43_write16(dev, B43_MMIO_PHY0, on ? 0 : 0xF4);
 }
+
+/* http://bcm-v4.sipsolutions.net/802.11/PHY/Cordic */
+struct b43_c32 b43_cordic(int theta)
+{
+        u32 arctg[] = { 2949120, 1740967, 919879, 466945, 234379, 117304,
+                      58666, 29335, 14668, 7334, 3667, 1833, 917, 458,
+                      229, 115, 57, 29, };
+        u8 i;
+        s32 tmp;
+        s8 signx = 1;
+        u32 angle = 0;
+        struct b43_c32 ret = { .i = 39797, .q = 0, };
+
+        while (theta > (180 << 16))
+                theta -= (360 << 16);
+        while (theta < -(180 << 16))
+                theta += (360 << 16);
+
+        if (theta > (90 << 16)) {
+                theta -= (180 << 16);
+                signx = -1;
+        } else if (theta < -(90 << 16)) {
+                theta += (180 << 16);
+                signx = -1;
+        }
+
+        for (i = 0; i <= 17; i++) {
+                if (theta > angle) {
+                        tmp = ret.i - (ret.q >> i);
+                        ret.q += ret.i >> i;
+                        ret.i = tmp;
+                        angle += arctg[i];
+                } else {
+                        tmp = ret.i + (ret.q >> i);
+                        ret.q -= ret.i >> i;
+                        ret.i = tmp;
+                        angle -= arctg[i];
+                }
+        }
+
+        ret.i *= signx;
+        ret.q *= signx;
+
+        return ret;
+}