[media] msi3101: few improvements for RF tuner

* Fix AM_MODE. Now it could work at least in theory, cannot test.
* Use greatest common divisor algo to divide PLL fractional parts.
* Fix IF frequency mode.
* + some very minor "style" issues

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/staging/media/msi3101/sdr-msi3101.c b/drivers/staging/media/msi3101/sdr-msi3101.c
index 839e601bd7c41f90b7fe665005070e04ee184b28..eebe1d042c91349deb5a716b7f0b9a47baa109c9 100644 (file)
--- a/drivers/staging/media/msi3101/sdr-msi3101.c
+++ b/drivers/staging/media/msi3101/sdr-msi3101.c
@@ -29,11 +29,9 @@
  * http://git.linuxtv.org/anttip/gr-kernel.git
  *
  * TODO:
- * I will look these:
- * - split RF tuner and USB ADC interface to own drivers (msi2500 and msi001)
- * - move controls to V4L2 API
- *
  * Help is very highly welcome for these + all the others you could imagine:
+ * - split USB ADC interface and RF tuner to own drivers (msi2500 and msi001)
+ * - move controls to V4L2 API
  * - use libv4l2 for stream format conversions
  * - gr-kernel: switch to v4l2_mmap (current read eats a lot of cpu)
  * - SDRSharp support
@@ -41,6 +39,7 @@
 
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/gcd.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-ctrls.h>
@@ -1331,25 +1330,25 @@ err:
 static int msi3101_set_tuner(struct msi3101_state *s)
 {
        int ret, i, len;
-       unsigned int n, m, thresh, frac, vco_step, tmp;
+       unsigned int n, m, thresh, frac, vco_step, tmp, f_if1;
        u32 reg;
        u64 f_vco;
-       u8 mode, lo_div;
+       u8 mode, filter_mode, lo_div;
        const struct msi3101_gain *gain_lut;
        static const struct {
                u32 rf;
                u8 mode;
                u8 lo_div;
        } band_lut[] = {
-               { 47000000, 0x01, 16}, /* AM_MODE1 */
-               {108000000, 0x02, 32}, /* VHF_MODE */
-               {330000000, 0x04, 16}, /* B3_MODE */
-               {960000000, 0x08,  4}, /* B45_MODE */
-               {      ~0U, 0x10,  2}, /* BL_MODE */
+               { 50000000, 0xe1, 16}, /* AM_MODE2, antenna 2 */
+               {108000000, 0x42, 32}, /* VHF_MODE */
+               {330000000, 0x44, 16}, /* B3_MODE */
+               {960000000, 0x48,  4}, /* B45_MODE */
+               {      ~0U, 0x50,  2}, /* BL_MODE */
        };
        static const struct {
                u32 freq;
-               u8 val;
+               u8 filter_mode;
        } if_freq_lut[] = {
                {      0, 0x03}, /* Zero IF */
                { 450000, 0x02}, /* 450 kHz IF */
@@ -1370,19 +1369,19 @@ static int msi3101_set_tuner(struct msi3101_state *s)
                {8000000, 0x07}, /* 8 MHz */
        };
 
-       unsigned int rf_freq = s->ctrl_tuner_rf->val64;
+       unsigned int f_rf = s->ctrl_tuner_rf->val64;
 
        /*
         * bandwidth (Hz)
         * 200000, 300000, 600000, 1536000, 5000000, 6000000, 7000000, 8000000
         */
-       int bandwidth = s->ctrl_tuner_bw->val;
+       unsigned int bandwidth = s->ctrl_tuner_bw->val;
 
        /*
         * intermediate frequency (Hz)
         * 0, 450000, 1620000, 2048000
         */
-       int if_freq = s->ctrl_tuner_if->val;
+       unsigned int f_if = s->ctrl_tuner_if->val;
 
        /*
         * gain reduction (dB)
@@ -1392,13 +1391,13 @@ static int msi3101_set_tuner(struct msi3101_state *s)
        int gain = s->ctrl_tuner_gain->val;
 
        dev_dbg(&s->udev->dev,
-                       "%s: rf_freq=%d bandwidth=%d if_freq=%d gain=%d\n",
-                       __func__, rf_freq, bandwidth, if_freq, gain);
+                       "%s: f_rf=%d bandwidth=%d f_if=%d gain=%d\n",
+                       __func__, f_rf, bandwidth, f_if, gain);
 
        ret = -EINVAL;
 
        for (i = 0; i < ARRAY_SIZE(band_lut); i++) {
-               if (rf_freq <= band_lut[i].rf) {
+               if (f_rf <= band_lut[i].rf) {
                        mode = band_lut[i].mode;
                        lo_div = band_lut[i].lo_div;
                        break;
@@ -1408,9 +1407,15 @@ static int msi3101_set_tuner(struct msi3101_state *s)
        if (i == ARRAY_SIZE(band_lut))
                goto err;
 
+       /* AM_MODE is upconverted */
+       if ((mode >> 0) & 0x1)
+               f_if1 =  5 * F_REF;
+       else
+               f_if1 =  0;
+
        for (i = 0; i < ARRAY_SIZE(if_freq_lut); i++) {
-               if (if_freq == if_freq_lut[i].freq) {
-                       if_freq = if_freq_lut[i].val;
+               if (f_if == if_freq_lut[i].freq) {
+                       filter_mode = if_freq_lut[i].filter_mode;
                        break;
                }
        }
@@ -1430,8 +1435,7 @@ static int msi3101_set_tuner(struct msi3101_state *s)
 
 #define F_OUT_STEP 1
 #define R_REF 4
-#define F_IF 0
-       f_vco = (rf_freq + F_IF) * lo_div;
+       f_vco = (f_rf + f_if + f_if1) * lo_div;
        n = f_vco / (F_REF * R_REF);
        m = f_vco % (F_REF * R_REF);
 
@@ -1439,7 +1443,12 @@ static int msi3101_set_tuner(struct msi3101_state *s)
        thresh = (F_REF * R_REF) / vco_step;
        frac = 1ul * thresh * m / (F_REF * R_REF);
 
-       /* Divide to reg max. After that RF resolution will be +-500Hz. */
+       /* Find out greatest common divisor and divide to smaller. */
+       tmp = gcd(thresh, frac);
+       thresh /= tmp;
+       frac /= tmp;
+
+       /* Force divide to reg max. Resolution will be reduced. */
        tmp = DIV_ROUND_UP(thresh, 4095);
        thresh = DIV_ROUND_CLOSEST(thresh, tmp);
        frac = DIV_ROUND_CLOSEST(frac, tmp);
@@ -1451,15 +1460,19 @@ static int msi3101_set_tuner(struct msi3101_state *s)
 
        dev_dbg(&s->udev->dev,
                        "%s: rf=%u:%u n=%d thresh=%d frac=%d\n",
-                               __func__, rf_freq, tmp, n, thresh, frac);
+                               __func__, f_rf, tmp, n, thresh, frac);
 
        ret = msi3101_tuner_write(s, 0x00000e);
+       if (ret)
+               goto err;
+
        ret = msi3101_tuner_write(s, 0x000003);
+       if (ret)
+               goto err;
 
        reg = 0 << 0;
        reg |= mode << 4;
-       reg |= 1 << 10;
-       reg |= if_freq << 12;
+       reg |= filter_mode << 12;
        reg |= bandwidth << 14;
        reg |= 0x02 << 17;
        reg |= 0x00 << 20;
@@ -1482,10 +1495,10 @@ static int msi3101_set_tuner(struct msi3101_state *s)
        if (ret)
                goto err;
 
-       if (rf_freq < 120000000) {
+       if (f_rf < 120000000) {
                gain_lut = msi3101_gain_lut_120;
                len = ARRAY_SIZE(msi3101_gain_lut_120);
-       } else if (rf_freq < 245000000) {
+       } else if (f_rf < 245000000) {
                gain_lut = msi3101_gain_lut_245;
                len = ARRAY_SIZE(msi3101_gain_lut_120);
        } else {