[PATCH 3/4] b43: update cordic code to match current specs

[Rafał Miłecki]

Signed-off-by: Rafał Miłecki <zaj...@gmail.com>
Tested-by: Larry Finger <larry.fin...@lwfinger.net>
---
 drivers/net/wireless/b43/phy_common.c |   19 +++++++++++++------
 drivers/net/wireless/b43/phy_common.h |    4 ++++
 drivers/net/wireless/b43/phy_lp.c     |    7 ++++---
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/net/wireless/b43/phy_common.c 
b/drivers/net/wireless/b43/phy_common.c
index 348a78f..868b829 100644
--- a/drivers/net/wireless/b43/phy_common.c
+++ b/drivers/net/wireless/b43/phy_common.c
@@ -422,21 +422,28 @@ 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 */
 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, };
-       int i, tmp, signx = 1, angle = 0;
+       u8 i;
+       s32 tmp;
+       s8 signx = 1;
+       u32 angle = 0;
        b43_c32 ret = { .i = 39797, .q = 0, };
 
-       theta = clamp_t(int, theta, -180, 180);
+       while (theta > (180 << 16))
+               theta -= (360 << 16);
+       while (theta < -(180 << 16))
+               theta += (360 << 16);
 
-       if (theta > 90) {
-               theta -= 180;
+       if (theta > (90 << 16)) {
+               theta -= (180 << 16);
                signx = -1;
-       } else if (theta < -90) {
-               theta += 180;
+       } else if (theta < -(90 << 16)) {
+               theta += (180 << 16);
                signx = -1;
        }
 
diff --git a/drivers/net/wireless/b43/phy_common.h 
b/drivers/net/wireless/b43/phy_common.h
index 7a38226..0716f07 100644
--- a/drivers/net/wireless/b43/phy_common.h
+++ b/drivers/net/wireless/b43/phy_common.h
@@ -8,6 +8,10 @@ struct b43_wldev;
 /* Complex number using 2 32-bit signed integers */
 typedef struct { s32 i, q; } b43_c32;
 
+#define CORDIC_CONVERT(value)  (((value) >= 0) ? \
+                                ((((value) >> 15) + 1) >> 1) : \
+                                -((((-(value)) >> 15) + 1) >> 1))
+
 /* PHY register routing bits */
 #define B43_PHYROUTE                   0x0C00 /* PHY register routing bits 
mask */
 #define  B43_PHYROUTE_BASE             0x0000 /* Base registers */
diff --git a/drivers/net/wireless/b43/phy_lp.c 
b/drivers/net/wireless/b43/phy_lp.c
index a142804..e770aad 100644
--- a/drivers/net/wireless/b43/phy_lp.c
+++ b/drivers/net/wireless/b43/phy_lp.c
@@ -1784,7 +1784,8 @@ static void lpphy_start_tx_tone(struct b43_wldev *dev, 
s32 freq, u16 max)
 {
        struct b43_phy_lp *lpphy = dev->phy.lp;
        u16 buf[64];
-       int i, samples = 0, angle = 0, rotation = (9 * freq) / 500;
+       int i, samples = 0, angle = 0;
+       int rotation = (((36 * freq) / 20) << 16) / 100;
        b43_c32 sample;
 
        lpphy->tx_tone_freq = freq;
@@ -1803,8 +1804,8 @@ static void lpphy_start_tx_tone(struct b43_wldev *dev, 
s32 freq, u16 max)
        for (i = 0; i < samples; i++) {
                sample = b43_cordic(angle);
                angle += rotation;
-               buf[i] = ((sample.i * max) & 0xFF) << 8;
-               buf[i] |= (sample.q * max) & 0xFF;
+               buf[i] = CORDIC_CONVERT((sample.i * max) & 0xFF) << 8;
+               buf[i] |= CORDIC_CONVERT((sample.q * max) & 0xFF);
        }
 
        b43_lptab_write_bulk(dev, B43_LPTAB16(5, 0), samples, buf);
-- 
1.6.4.2

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