[media] af9033: use 64-bit div macro where possible

Replace Booth's binary division algo with 64-bit multiply and division.
Fix related IF calculations.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/dvb-frontends/af9033.c b/drivers/media/dvb-frontends/af9033.c
index c61d879..765d05a 100644 (file)
--- a/drivers/media/dvb-frontends/af9033.c
+++ b/drivers/media/dvb-frontends/af9033.c
@@ -79,40 +79,14 @@ err:
        return ret;
 }
 
-static u32 af9033_div(struct af9033_dev *dev, u32 a, u32 b, u32 x)
-{
-       u32 r = 0, c = 0, i;
-
-       dev_dbg(&dev->client->dev, "a=%d b=%d x=%d\n", a, b, x);
-
-       if (a > b) {
-               c = a / b;
-               a = a - c * b;
-       }
-
-       for (i = 0; i < x; i++) {
-               if (a >= b) {
-                       r += 1;
-                       a -= b;
-               }
-               a <<= 1;
-               r <<= 1;
-       }
-       r = (c << (u32)x) + r;
-
-       dev_dbg(&dev->client->dev, "a=%d b=%d x=%d r=%d r=%x\n", a, b, x, r, r);
-
-       return r;
-}
-
 static int af9033_init(struct dvb_frontend *fe)
 {
        struct af9033_dev *dev = fe->demodulator_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        int ret, i, len;
+       unsigned int utmp;
        const struct reg_val *init;
        u8 buf[4];
-       u32 adc_cw, clock_cw;
        struct reg_val_mask tab[] = {
                { 0x80fb24, 0x00, 0x08 },
                { 0x80004c, 0x00, 0xff },
@@ -143,19 +117,18 @@ static int af9033_init(struct dvb_frontend *fe)
        };
 
        /* program clock control */
-       clock_cw = af9033_div(dev, dev->cfg.clock, 1000000ul, 19ul);
-       buf[0] = (clock_cw >>  0) & 0xff;
-       buf[1] = (clock_cw >>  8) & 0xff;
-       buf[2] = (clock_cw >> 16) & 0xff;
-       buf[3] = (clock_cw >> 24) & 0xff;
-
-       dev_dbg(&dev->client->dev, "clock=%d clock_cw=%08x\n",
-                       dev->cfg.clock, clock_cw);
-
+       utmp = div_u64((u64)dev->cfg.clock * 0x80000, 1000000);
+       buf[0] = (utmp >>  0) & 0xff;
+       buf[1] = (utmp >>  8) & 0xff;
+       buf[2] = (utmp >> 16) & 0xff;
+       buf[3] = (utmp >> 24) & 0xff;
        ret = regmap_bulk_write(dev->regmap, 0x800025, buf, 4);
        if (ret)
                goto err;
 
+       dev_dbg(&dev->client->dev, "clk=%u clk_cw=%08x\n",
+               dev->cfg.clock, utmp);
+
        /* program ADC control */
        for (i = 0; i < ARRAY_SIZE(clock_adc_lut); i++) {
                if (clock_adc_lut[i].clock == dev->cfg.clock)
@@ -168,18 +141,17 @@ static int af9033_init(struct dvb_frontend *fe)
                goto err;
        }
 
-       adc_cw = af9033_div(dev, clock_adc_lut[i].adc, 1000000ul, 19ul);
-       buf[0] = (adc_cw >>  0) & 0xff;
-       buf[1] = (adc_cw >>  8) & 0xff;
-       buf[2] = (adc_cw >> 16) & 0xff;
-
-       dev_dbg(&dev->client->dev, "adc=%d adc_cw=%06x\n",
-                       clock_adc_lut[i].adc, adc_cw);
-
+       utmp = div_u64((u64)clock_adc_lut[i].adc * 0x80000, 1000000);
+       buf[0] = (utmp >>  0) & 0xff;
+       buf[1] = (utmp >>  8) & 0xff;
+       buf[2] = (utmp >> 16) & 0xff;
        ret = regmap_bulk_write(dev->regmap, 0x80f1cd, buf, 3);
        if (ret)
                goto err;
 
+       dev_dbg(&dev->client->dev, "adc=%u adc_cw=%06x\n",
+               clock_adc_lut[i].adc, utmp);
+
        /* program register table */
        for (i = 0; i < ARRAY_SIZE(tab); i++) {
                ret = regmap_update_bits(dev->regmap, tab[i].reg, tab[i].mask,
@@ -397,9 +369,10 @@ static int af9033_set_frontend(struct dvb_frontend *fe)
 {
        struct af9033_dev *dev = fe->demodulator_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
-       int ret, i, spec_inv, sampling_freq;
+       int ret, i;
+       unsigned int utmp, adc_freq;
        u8 tmp, buf[3], bandwidth_reg_val;
-       u32 if_frequency, freq_cw, adc_freq;
+       u32 if_frequency;
 
        dev_dbg(&dev->client->dev, "frequency=%d bandwidth_hz=%d\n",
                        c->frequency, c->bandwidth_hz);
@@ -449,8 +422,6 @@ static int af9033_set_frontend(struct dvb_frontend *fe)
 
        /* program frequency control */
        if (c->bandwidth_hz != dev->bandwidth_hz) {
-               spec_inv = dev->cfg.spec_inv ? -1 : 1;
-
                for (i = 0; i < ARRAY_SIZE(clock_adc_lut); i++) {
                        if (clock_adc_lut[i].clock == dev->cfg.clock)
                                break;
@@ -464,42 +435,30 @@ static int af9033_set_frontend(struct dvb_frontend *fe)
                }
                adc_freq = clock_adc_lut[i].adc;
 
+               if (dev->cfg.adc_multiplier == AF9033_ADC_MULTIPLIER_2X)
+                       adc_freq = 2 * adc_freq;
+
                /* get used IF frequency */
                if (fe->ops.tuner_ops.get_if_frequency)
                        fe->ops.tuner_ops.get_if_frequency(fe, &if_frequency);
                else
                        if_frequency = 0;
 
-               sampling_freq = if_frequency;
+               utmp = DIV_ROUND_CLOSEST_ULL((u64)if_frequency * 0x800000,
+                                            adc_freq);
 
-               while (sampling_freq > (adc_freq / 2))
-                       sampling_freq -= adc_freq;
-
-               if (sampling_freq >= 0)
-                       spec_inv *= -1;
-               else
-                       sampling_freq *= -1;
-
-               freq_cw = af9033_div(dev, sampling_freq, adc_freq, 23ul);
-
-               if (spec_inv == -1)
-                       freq_cw = 0x800000 - freq_cw;
-
-               if (dev->cfg.adc_multiplier == AF9033_ADC_MULTIPLIER_2X)
-                       freq_cw /= 2;
-
-               buf[0] = (freq_cw >>  0) & 0xff;
-               buf[1] = (freq_cw >>  8) & 0xff;
-               buf[2] = (freq_cw >> 16) & 0x7f;
-
-               /* FIXME: there seems to be calculation error here... */
-               if (if_frequency == 0)
-                       buf[2] = 0;
+               if (!dev->cfg.spec_inv && if_frequency)
+                       utmp = 0x800000 - utmp;
 
+               buf[0] = (utmp >>  0) & 0xff;
+               buf[1] = (utmp >>  8) & 0xff;
+               buf[2] = (utmp >> 16) & 0xff;
                ret = regmap_bulk_write(dev->regmap, 0x800029, buf, 3);
                if (ret)
                        goto err;
 
+               dev_dbg(&dev->client->dev, "if_frequency_cw=%06x\n", utmp);
+
                dev->bandwidth_hz = c->bandwidth_hz;
        }
 

diff --git a/drivers/media/dvb-frontends/af9033_priv.h b/drivers/media/dvb-frontends/af9033_priv.h
index 701c508..28d14dc 100644 (file)
--- a/drivers/media/dvb-frontends/af9033_priv.h
+++ b/drivers/media/dvb-frontends/af9033_priv.h
@@ -26,6 +26,7 @@
 #include "af9033.h"
 #include <linux/math64.h>
 #include <linux/regmap.h>
+#include <linux/kernel.h>
 
 struct reg_val {
        u32 reg;