b43: update cordic code to match current specs

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Rafał Miłecki 2010-01-25 19:00:00 +01:00 committed by John W. Linville
parent 9865045403
commit 6f98e62a9f
3 changed files with 21 additions and 9 deletions

View File

@ -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 */
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, };
int i, tmp, signx = 1, angle = 0;
u8 i;
s32 tmp;
s8 signx = 1;
u32 angle = 0;
struct 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;
}

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@ -8,6 +8,10 @@ struct b43_wldev;
/* Complex number using 2 32-bit signed integers */
struct b43_c32 { s32 i, q; };
#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 */

View File

@ -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;
struct 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);