Add power control to reboot board without unplugging

src/main.rs

@@ -41,7 +41,7 @@ use jlink_rtt::Output;
 use platform::{
     display::{Color, Size2d},
     gpio::GPIO,
-    // uart::MiniUart,
+    power::Power,
     vc::VC,
 };
 

src/platform/mod.rs

@@ -2,6 +2,7 @@ pub mod display;
 pub mod gpio;
 pub mod mailbox;
 pub mod mini_uart;
+pub mod power;
 pub mod rpi3;
 pub mod uart;
 pub mod vc;

src/platform/power.rs

@@ -0,0 +1,143 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2018-2019 Andre Richter <andre.o.richter@gmail.com>
+ *
+ * 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 super::mailbox;
+use crate::arch::loop_delay;
+use crate::platform::{gpio, rpi3::BcmHost};
+use core::ops;
+use core::sync::atomic::{compiler_fence, Ordering};
+use register::mmio::*;
+
+const POWER_BASE: u32 = BcmHost::get_peripheral_address() + 0x100_01C;
+
+#[allow(non_snake_case)]
+#[repr(C)]
+pub struct RegisterBlock {
+    PM_RSTC: ReadWrite<u32>, // 0x1C
+    PM_RSTS: ReadWrite<u32>, // 0x20
+    PM_WDOG: ReadWrite<u32>, // 0x24
+}
+
+const PM_PASSWORD: u32 = 0x5a_000_000;
+const PM_RSTC_WRCFG_CLR: u32 = 0xffff_ffcf;
+const PM_RSTC_WRCFG_FULL_RESET: u32 = 0x0000_0020;
+
+// The Raspberry Pi firmware uses the RSTS register to know which
+// partition to boot from. The partition value is spread into bits 0, 2,
+// 4, 6, 8, 10. Partition 63 is a special partition used by the
+// firmware to indicate halt.
+const PM_RSTS_RASPBERRYPI_HALT: u32 = 0x555;
+
+pub enum PowerError {
+    MailboxError,
+}
+pub type Result<T> = ::core::result::Result<T, PowerError>;
+
+/// Public interface to the Power subsystem
+pub struct Power;
+
+impl ops::Deref for Power {
+    type Target = RegisterBlock;
+
+    fn deref(&self) -> &Self::Target {
+        unsafe { &*Self::ptr() }
+    }
+}
+
+impl Power {
+    pub fn new() -> Power {
+        Power
+    }
+
+    /// Returns a pointer to the register block
+    fn ptr() -> *const RegisterBlock {
+        POWER_BASE as *const _
+    }
+
+    /// Shutdown the board
+    /*
+        pub fn off(&self, mbox: &mut mbox::Mbox, gpio: &gpio::GPIO) -> Result<()> {
+            // power off devices one by one
+            for dev_id in 0..16 {
+                mbox.buffer[0] = 8 * 4;
+                mbox.buffer[1] = mbox::REQUEST;
+                mbox.buffer[2] = mbox::tag::SETPOWER;
+                mbox.buffer[3] = 8;
+                mbox.buffer[4] = 8;
+                mbox.buffer[5] = dev_id; // device id
+                mbox.buffer[6] = 0; // bit 0: off, bit 1: no wait
+                mbox.buffer[7] = mbox::tag::LAST;
+
+                // Insert a compiler fence that ensures that all stores to the
+                // mbox buffer are finished before the GPU is signaled (which
+                // is done by a store operation as well).
+                compiler_fence(Ordering::Release);
+
+                if mbox.call(mbox::channel::PROP).is_err() {
+                    return Err(PowerError::MailboxError); // Abort if UART clocks couldn't be set
+                };
+            }
+
+            // power off gpio pins (but not VCC pins)
+            gpio.GPFSEL0.set(0);
+            gpio.GPFSEL1.set(0);
+            gpio.GPFSEL2.set(0);
+            gpio.GPFSEL3.set(0);
+            gpio.GPFSEL4.set(0);
+            gpio.GPFSEL5.set(0);
+
+            gpio.GPPUD.set(0);
+            loop_delay(150);
+
+            gpio.GPPUDCLK0.set(0xffff_ffff);
+            gpio.GPPUDCLK1.set(0xffff_ffff);
+            loop_delay(150);
+
+            // flush GPIO setup
+            gpio.GPPUDCLK0.set(0);
+            gpio.GPPUDCLK1.set(0);
+
+            // We set the watchdog hard reset bit here to distinguish this
+            // reset from the normal (full) reset. bootcode.bin will not
+            // reboot after a hard reset.
+            let mut val = self.PM_RSTS.get();
+            val |= PM_PASSWORD | PM_RSTS_RASPBERRYPI_HALT;
+            self.PM_RSTS.set(val);
+
+            // Continue with normal reset mechanism
+            self.reset();
+        }
+    */
+    /// Reboot
+    pub fn reset(&self) -> ! {
+        // use a timeout of 10 ticks (~150us)
+        self.PM_WDOG.set(PM_PASSWORD | 10);
+        let mut val = self.PM_RSTC.get();
+        val &= PM_RSTC_WRCFG_CLR;
+        val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
+        self.PM_RSTC.set(val);
+
+        loop {}
+    }
+}