From: Tilman Sauerbeck <tilman@code-monkey.de>
Date: Mon, 17 Jun 2019 05:34:52 +0000 (+0200)
Subject: common: Add the clock module.
X-Git-Url: http://git.code-monkey.de/?p=gps-watch.git;a=commitdiff_plain;h=4ce1b228434e7b4dfa78f71070e1d063365828eb

common: Add the clock module.

So far this module only knows how to bring the system to PEE mode.
---

diff --git a/SConscript.libcommon b/SConscript.libcommon
index 42c0762..69f317c 100644
--- a/SConscript.libcommon
+++ b/SConscript.libcommon
@@ -5,6 +5,7 @@ source_files_rs = [
     'src/common/lib.rs', # Must be listed first (see below).
     'src/common/register.rs',
     'src/common/nvic.rs',
+    'src/common/clock.rs',
 ]
 
 source_files_c = [
diff --git a/src/common/clock.rs b/src/common/clock.rs
new file mode 100644
index 0000000..c1bbb10
--- /dev/null
+++ b/src/common/clock.rs
@@ -0,0 +1,148 @@
+/*
+ * Copyright (c) 2019 Tilman Sauerbeck (tilman at code-monkey de)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+use register;
+
+type Reg8 = register::Register<u8>;
+type Reg32 = register::Register<u32>;
+
+const SIM_BASE: u32 = 0x40047000;
+
+const SIM_CLKDIV1: u32 = SIM_BASE + 0x1044;
+
+const SIM_CLKDIV1_OUTDIV4_SHIFT: u32 = 16;
+const SIM_CLKDIV1_OUTDIV1_SHIFT: u32 = 28;
+
+const MCG_BASE: u32 = 0x40064000;
+
+const MCG_C1: u32 = MCG_BASE + 0;
+const MCG_C2: u32 = MCG_BASE + 1;
+const MCG_C4: u32 = MCG_BASE + 3;
+const MCG_C5: u32 = MCG_BASE + 4;
+const MCG_C6: u32 = MCG_BASE + 5;
+const MCG_S : u32 = MCG_BASE + 6;
+
+const MCG_C1_FRDIV_SHIFT: u32 = 3;
+const MCG_C1_CLKS_SHIFT: u32 = 6;
+
+const MCG_C2_IRCS: u8 = 1 << 0;
+const MCG_C2_EREFS0: u8 = 1 << 2;
+const MCG_C2_RANGE0_SHIFT: u32 = 4;
+
+const MCG_C4_DMX32: u8 = 1 << 7;
+const MCG_C4_DRST_DRS_MASK: u8 = 3 << 5;
+
+const MCG_C5_PLLSTEN0: u8 = 1 << 5;
+const MCG_C5_PRDIV0_SHIFT: u32 = 0;
+
+const MCG_C6_VDIV0_SHIFT: u32 = 0;
+const MCG_C6_CME0: u8 = 1 << 5;
+const MCG_C6_PLLS: u8 = 1 << 6;
+
+const MCG_S_CLKST_SHIFT: u32 = 2;
+const MCG_S_CLKST_MASK: u8 = 3 << MCG_S_CLKST_SHIFT;
+const MCG_S_IREFST: u8 = 1 << 4;
+const MCG_S_LOCK0: u8 = 1 << 6;
+
+fn configure_clkdiv() {
+    let mut clkdiv1 = Reg32::new(SIM_CLKDIV1);
+
+    clkdiv1.write(1 << SIM_CLKDIV1_OUTDIV4_SHIFT);
+    clkdiv1.modify(|v| v | (1 << SIM_CLKDIV1_OUTDIV1_SHIFT));
+}
+
+fn switch_to_fbe() {
+    let mut c2 = Reg8::new(MCG_C2);
+    c2.write((2 << MCG_C2_RANGE0_SHIFT) | MCG_C2_EREFS0 | MCG_C2_IRCS);
+
+    let mut c1 = Reg8::new(MCG_C1);
+    c1.write((2 << MCG_C1_CLKS_SHIFT) | (3 << MCG_C1_FRDIV_SHIFT));
+
+    let mut c4 = Reg8::new(MCG_C4);
+    c4.modify(|v| v & !MCG_C4_DMX32 & !MCG_C4_DRST_DRS_MASK);
+
+    let mut c5 = Reg8::new(MCG_C5);
+    c5.write(MCG_C5_PLLSTEN0 | (11 << MCG_C5_PRDIV0_SHIFT));
+
+    let mut c6 = Reg8::new(MCG_C6);
+    c6.write(24 << MCG_C6_VDIV0_SHIFT);
+
+    let s = Reg8::new(MCG_S);
+
+    while (s.read() & MCG_S_IREFST) != 0 {
+    }
+
+    while (s.read() & MCG_S_CLKST_MASK) != (2 << MCG_S_CLKST_SHIFT) {
+    }
+}
+
+fn switch_to_pbe() {
+    let mut c1 = Reg8::new(MCG_C1);
+    c1.write((2 << MCG_C1_CLKS_SHIFT) | (3 << MCG_C1_FRDIV_SHIFT));
+
+    let mut c2 = Reg8::new(MCG_C2);
+    c2.write((2 << MCG_C2_RANGE0_SHIFT) | MCG_C2_EREFS0 | MCG_C2_IRCS);
+
+    let mut c5 = Reg8::new(MCG_C5);
+    c5.write(MCG_C5_PLLSTEN0 | (11 << MCG_C5_PRDIV0_SHIFT));
+
+    let mut c6 = Reg8::new(MCG_C6);
+    c6.write(MCG_C6_PLLS | 24 << MCG_C6_VDIV0_SHIFT);
+
+    let s = Reg8::new(MCG_S);
+
+    while (s.read() & MCG_S_CLKST_MASK) != (2 << MCG_S_CLKST_SHIFT) {
+    }
+
+    while (s.read() & MCG_S_LOCK0) == 0 {
+    }
+}
+
+fn switch_to_pee() {
+    let mut c1 = Reg8::new(MCG_C1);
+    c1.write(3 << MCG_C1_FRDIV_SHIFT);
+
+    let mut c2 = Reg8::new(MCG_C2);
+    c2.write((2 << MCG_C2_RANGE0_SHIFT) | MCG_C2_EREFS0 | MCG_C2_IRCS);
+
+    let mut c5 = Reg8::new(MCG_C5);
+    c5.write(MCG_C5_PLLSTEN0 | (11 << MCG_C5_PRDIV0_SHIFT));
+
+    let mut c6 = Reg8::new(MCG_C6);
+    c6.write(MCG_C6_PLLS | 24 << MCG_C6_VDIV0_SHIFT);
+
+    let s = Reg8::new(MCG_S);
+
+    while (s.read() & MCG_S_CLKST_MASK) != (3 << MCG_S_CLKST_SHIFT) {
+    }
+
+    c6.modify(|v| v | MCG_C6_CME0);
+}
+
+pub unsafe fn configure() {
+    configure_clkdiv();
+
+    switch_to_fbe();
+    switch_to_pbe();
+    switch_to_pee();
+}
diff --git a/src/common/lib.rs b/src/common/lib.rs
index 0fa0f6b..ac388b4 100644
--- a/src/common/lib.rs
+++ b/src/common/lib.rs
@@ -28,6 +28,7 @@
 
 pub mod register;
 pub mod nvic;
+pub mod clock;
 
 #[lang="eh_personality"]
 extern fn eh_personality() {