From a792fa11bea0bde00aa9aaf0aa6c2640bdb633a3 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Fri, 3 Aug 2018 16:19:11 +0300
Subject: Implement r820t init

---
 src/devices/mod.rs   |  4 +++-
 src/devices/r820t.rs | 18 ++++++++++++++++--
 src/usb.rs           | 16 ++++++++++++++++
 3 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/src/devices/mod.rs b/src/devices/mod.rs
index 05dd2a3..659b131 100644
--- a/src/devices/mod.rs
+++ b/src/devices/mod.rs
@@ -1,3 +1,5 @@
+use usb::Usb;
+
 pub mod fc0013;
 pub mod r820t;
 
@@ -10,5 +12,5 @@ pub struct DeviceInfo {
 }
 
 pub trait Device {
-    fn init(&self);
+    fn init(&self, &Usb);
 }
diff --git a/src/devices/r820t.rs b/src/devices/r820t.rs
index fec572c..46046bc 100644
--- a/src/devices/r820t.rs
+++ b/src/devices/r820t.rs
@@ -1,4 +1,7 @@
 use super::{DeviceInfo, Device};
+use usb::Usb;
+
+const R82XX_IF_FREQ: u32 = 3570000;
 
 pub struct R820T {
     pub device: DeviceInfo
@@ -21,7 +24,18 @@ impl R820T {
 }
 
 impl Device for R820T {
-    fn init(&self) {
-        println!("Init {}", self.device.name);
+    fn init(&self, usb: &Usb) {
+        // disable Zero-IF mode
+        usb.demod_write_reg(1, 0xb1, 0x1a, 1);
+
+        // only enable In-phase ADC input
+        usb.demod_write_reg(0, 0x08, 0x4d, 1);
+
+        // the R82XX use 3.57 MHz IF for the DVB-T 6 MHz mode, and
+        // 4.57 MHz for the 8 MHz mode
+        usb.set_if_freq(R82XX_IF_FREQ);
+
+        // enable spectrum inversion
+        usb.demod_write_reg(1, 0x15, 0x01, 1);
     }
 }
diff --git a/src/usb.rs b/src/usb.rs
index fdae356..035786e 100644
--- a/src/usb.rs
+++ b/src/usb.rs
@@ -28,6 +28,9 @@ const FIR_DEFAULT: [u8; FIR_LENGTH] = [
     0x9c, 0x0d, 0x71, 0x11, 0x14, 0x71, 0x74, 0x19, 0x41, 0xa5,
 ];
 
+const DEF_RTL_XTAL_FREQ: u32 = 28800000;
+const MIN_RTL_XTAL_FREQ: u32 = DEF_RTL_XTAL_FREQ - 1000;
+const MAX_RTL_XTAL_FREQ: u32 = DEF_RTL_XTAL_FREQ + 1000;
 
 const CTRL_TIMEOUT: Duration = Duration::from_millis(300);
 
@@ -181,6 +184,19 @@ impl<'a> Usb<'a> {
         self.demod_write_reg(0, 0x0d, 0x83, 1);
     }
 
+    pub fn set_if_freq(&self, freq: u32) {
+        let rtl_xtal: u32 = DEF_RTL_XTAL_FREQ; // need to apply PPM correction
+        let base = 1u32 << 22;
+        let if_freq: i32 = (freq as f64 * base as f64 / rtl_xtal as f64 * -1f64) as i32;
+
+        let tmp = ((if_freq >> 16) as u16) & 0x3f;
+        self.demod_write_reg(1, 0x19, tmp, 1);
+        let tmp = ((if_freq >> 8) as u16) & 0xff;
+        self.demod_write_reg(1, 0x1a, tmp, 1);
+        let tmp = if_freq as u16 & 0xff;
+        self.demod_write_reg(1, 0x1b, tmp, 1);
+    }
+
     pub fn deinit_baseband(&self) {
         // deinit tuner?
 
-- 
cgit v1.3.1