Add miso pullup to spi configuration, add input as field for speed

2 files changed, 63 insertions, 2 deletions

diff --git a/embassy-stm32/src/gpio.rs b/embassy-stm32/src/gpio.rs
index 214813a42..d2db0a257 100644
--- a/embassy-stm32/src/gpio.rs
+++ b/embassy-stm32/src/gpio.rs
@@ -265,6 +265,7 @@ impl From<Pull> for vals::Pupdr {
 #[derive(Debug, Copy, Clone)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Speed {
+    Input,
     Low,
     Medium,
     #[cfg(not(any(syscfg_f0, gpio_v1)))]
@@ -278,6 +279,7 @@ impl From<Speed> for vals::Mode {
         use Speed::*;
 
         match speed {
+            Input => vals::Mode::INPUT,
             Low => vals::Mode::OUTPUT2MHZ,
             Medium => vals::Mode::OUTPUT10MHZ,
             VeryHigh => vals::Mode::OUTPUT50MHZ,
@@ -291,6 +293,7 @@ impl From<Speed> for vals::Ospeedr {
         use Speed::*;
 
         match speed {
+            Input => vals::Ospeedr::LOWSPEED,
             Low => vals::Ospeedr::LOWSPEED,
             Medium => vals::Ospeedr::MEDIUMSPEED,
             #[cfg(not(syscfg_f0))]
@@ -676,6 +679,39 @@ pub(crate) trait SealedPin {
         #[cfg(gpio_v2)]
         self.block().ospeedr().modify(|w| w.set_ospeedr(pin, speed.into()));
     }
+
+
+    /// Get the pull-up configuration.
+    #[inline]
+    fn pull(&self) -> Pull {
+        critical_section::with(|_| {
+            let r = self.block();
+            let n = self._pin() as usize;
+            #[cfg(gpio_v1)]
+            {
+                let crlh = if n < 8 { 0 } else { 1 };
+                match r.cr(crlh).cnf(n % 8) {
+                    vals::CnfIn::FLOATING => Pull::None,
+                    _ => if r.bsrr().read().bs(n % 8) {
+                        Pull::Up
+                    } else if r.bsrr().read().br(n % 8) {
+                        Pull::Down
+                    } else {
+                        Pull::None
+                    }
+                }
+            }
+            #[cfg(gpio_v2)]
+            {
+                match r.pupdr().read().pupdr(n % 8) {
+                    vals::Pupdr::FLOATING => Pull::None,
+                    vals::Pupdr::PULLDOWN => Pull::Down,
+                    vals::Pupdr::PULLUP => Pull::Up,
+                    vals::Pupdr::_RESERVED_3 => Pull::None,
+                }
+            }
+        })
+    }
 }
 
 /// GPIO pin trait.
diff --git a/embassy-stm32/src/spi/mod.rs b/embassy-stm32/src/spi/mod.rs
index c39ef1913..bcd6b0bf4 100644
--- a/embassy-stm32/src/spi/mod.rs
+++ b/embassy-stm32/src/spi/mod.rs
@@ -50,6 +50,11 @@ pub struct Config {
     pub bit_order: BitOrder,
     /// Clock frequency.
     pub frequency: Hertz,
+    /// Enable internal pullup on MISO.
+    ///
+    /// There are some ICs that require a pull-up on the MISO pin for some applications.
+    /// If you  are unsure, you probably don't need this.
+    pub miso_pullup: bool,
 }
 
 impl Default for Config {
@@ -58,6 +63,7 @@ impl Default for Config {
             mode: MODE_0,
             bit_order: BitOrder::MsbFirst,
             frequency: Hertz(1_000_000),
+            miso_pullup: false,
         }
     }
 }
@@ -275,6 +281,16 @@ impl<'d, T: Instance, M: PeriMode> Spi<'d, T, M> {
             BitOrder::MsbFirst
         };
 
+        let miso_pullup = match &self.miso {
+            None => false,
+            Some(pin) => 
+            if pin.pull() == Pull::Up {
+                true
+            } else {
+                false
+            }
+        };
+
         #[cfg(any(spi_v1, spi_f1, spi_v2))]
         let br = cfg.br();
         #[cfg(any(spi_v3, spi_v4, spi_v5))]
@@ -287,6 +303,7 @@ impl<'d, T: Instance, M: PeriMode> Spi<'d, T, M> {
             mode: Mode { polarity, phase },
             bit_order,
             frequency,
+            miso_pullup,
         }
     }
 
@@ -409,7 +426,11 @@ impl<'d, T: Instance> Spi<'d, T, Blocking> {
             peri,
             new_pin!(sck, AFType::OutputPushPull, Speed::VeryHigh, config.sck_pull_mode()),
             new_pin!(mosi, AFType::OutputPushPull, Speed::VeryHigh),
-            new_pin!(miso, AFType::Input, Speed::VeryHigh),
+            new_pin!(miso, AFType::Input, Speed::Input, 
+                match config.miso_pullup {
+                    true => Pull::Up,
+                    false => Pull::None,
+                }),
             None,
             None,
             config,
@@ -427,7 +448,11 @@ impl<'d, T: Instance> Spi<'d, T, Blocking> {
             peri,
             new_pin!(sck, AFType::OutputPushPull, Speed::VeryHigh, config.sck_pull_mode()),
             None,
-            new_pin!(miso, AFType::Input, Speed::VeryHigh),
+            new_pin!(miso, AFType::Input, Speed::Input, 
+                match config.miso_pullup {
+                    true => Pull::Up,
+                    false => Pull::None,
+                }),
             None,
             None,
             config,