[media] msi3101: correct ADC sampling rate calc a little bit

No need to compare numbers, we could just store that fractional
value MSB directly.

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

1 files changed, 8 insertions, 15 deletions

diff --git a/drivers/staging/media/msi3101/sdr-msi3101.c b/drivers/staging/media/msi3101/sdr-msi3101.c
index 2b73fc1f39f4..04bbbdf0acd3 100644
--- a/drivers/staging/media/msi3101/sdr-msi3101.c
+++ b/drivers/staging/media/msi3101/sdr-msi3101.c
@@ -987,7 +987,7 @@ static int msi3101_tuner_write(struct msi3101_state *s, u32 data)
 #define DIV_R_IN 2
 static int msi3101_set_usb_adc(struct msi3101_state *s)
 {
-        int ret, div_n, div_m, div_r_out, f_sr, f_vco;
+        int ret, div_n, div_m, div_r_out, f_sr, f_vco, fract;
         u32 reg4, reg3;
         /*
          * Synthesizer config is just a educated guess...
@@ -998,7 +998,7 @@ static int msi3101_set_usb_adc(struct msi3101_state *s)
          * [12:10] output divider
          * [13]    0 ?
          * [14]    0 ?
-         * [15]    increase sr by max fract
+         * [15]    fractional MSB, bit 20
          * [16:19] N
          * [23:20] ?
          * [24:31] 0x01
@@ -1019,6 +1019,7 @@ static int msi3101_set_usb_adc(struct msi3101_state *s)
 
         f_sr = s->ctrl_sampling_rate->val64;
         reg3 = 0x01c00303;
+        reg4 = 0x00000004;
 
         for (div_r_out = 4; div_r_out < 16; div_r_out += 2) {
                 f_vco = f_sr * div_r_out * 12;
@@ -1030,24 +1031,16 @@ static int msi3101_set_usb_adc(struct msi3101_state *s)
 
         div_n = f_vco / (F_REF * DIV_R_IN);
         div_m = f_vco % (F_REF * DIV_R_IN);
+        fract = 0x200000ul * div_m / (F_REF * DIV_R_IN);
 
         reg3 |= div_n << 16;
         reg3 |= (div_r_out / 2 - 1) << 10;
-        reg4 = 0x0ffffful * div_m / F_REF;
-
-        if (reg4 >= 0x0ffffful) {
-                dev_dbg(&s->udev->dev,
-                                "%s: extending fractional part value %08x\n",
-                                __func__, reg4);
-                reg4 -= 0x0ffffful;
-                reg3 |= 1 << 15;
-        }
-
-        reg4 = (reg4 << 8) | 0x04;
+        reg3 |= ((fract >> 20) & 0x000001) << 15; /* [20] */
+        reg4 |= ((fract >>  0) & 0x0fffff) <<  8; /* [19:0] */
 
         dev_dbg(&s->udev->dev,
-                        "%s: f_sr=%d f_vco=%d div_n=%d div_m=%d div_r_out=%d reg4=%08x\n",
-                        __func__, f_sr, f_vco, div_n, div_m, div_r_out, reg4);
+                        "%s: f_sr=%d f_vco=%d div_n=%d div_m=%d div_r_out=%d reg3=%08x reg4=%08x\n",
+                        __func__, f_sr, f_vco, div_n, div_m, div_r_out, reg3, reg4);
 
         ret = msi3101_ctrl_msg(s, CMD_WREG, 0x00608008);
         if (ret)