From 6f98e62a9f1bdbd83d8d1be8c2ca6f58099846ef Mon Sep 17 00:00:00 2001 From: =?utf8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Mon, 25 Jan 2010 19:00:00 +0100 Subject: [PATCH] b43: update cordic code to match current specs MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Rafał Miłecki Tested-by: Larry Finger Signed-off-by: John W. Linville --- 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 446c41bb1e9f..8f7d7eff2d80 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 */ 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; } diff --git a/drivers/net/wireless/b43/phy_common.h b/drivers/net/wireless/b43/phy_common.h index 9e4de47d0608..bd480b481bfc 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 */ 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 */ diff --git a/drivers/net/wireless/b43/phy_lp.c b/drivers/net/wireless/b43/phy_lp.c index 453585073437..185219e0a552 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; 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); -- 2.20.1