stm32 i2c slave

embassy-stm32/src/i2c/config.rs

@@ -0,0 +1,170 @@
+#[cfg(gpio_v2)]
+use crate::gpio::Pull;
+use crate::gpio::{AfType, OutputType, Speed};
+
+#[repr(u8)]
+#[derive(Copy, Clone)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// Bits of the I2C OA2 register to mask out.
+pub enum AddrMask {
+    /// No mask
+    NOMASK,
+    /// OA2\[1\] is masked and don’t care. Only OA2\[7:2\] are compared.
+    MASK1,
+    /// OA2\[2:1\] are masked and don’t care. Only OA2\[7:3\] are compared.
+    MASK2,
+    /// OA2\[3:1\] are masked and don’t care. Only OA2\[7:4\] are compared.
+    MASK3,
+    /// OA2\[4:1\] are masked and don’t care. Only OA2\[7:5\] are compared.
+    MASK4,
+    /// OA2\[5:1\] are masked and don’t care. Only OA2\[7:6\] are compared.
+    MASK5,
+    /// OA2\[6:1\] are masked and don’t care. Only OA2\[7:6\] are compared.
+    MASK6,
+    /// OA2\[7:1\] are masked and don’t care. No comparison is done, and all (except reserved) 7-bit received addresses are acknowledged
+    MASK7,
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// An I2C address. Either 7 or 10 bit.
+pub enum Address {
+    /// A 7 bit address
+    SevenBit(u8),
+    /// A 10 bit address.
+    ///
+    /// When using an address to configure the Own Address, only the OA1 register can be set to a 10-bit address.
+    TenBit(u16),
+}
+impl From<u8> for Address {
+    fn from(value: u8) -> Self {
+        Address::SevenBit(value)
+    }
+}
+impl From<u16> for Address {
+    fn from(value: u16) -> Self {
+        assert!(value < 0x400, "Ten bit address must be less than 0x400");
+        Address::TenBit(value)
+    }
+}
+impl Address {
+    /// Get the inner address as a u16.
+    ///
+    /// For 7 bit addresses, the u8 that was used to store the address is returned as a u16.
+    pub fn addr(&self) -> u16 {
+        match self {
+            Address::SevenBit(addr) => *addr as u16,
+            Address::TenBit(addr) => *addr,
+        }
+    }
+}
+
+#[derive(Copy, Clone)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// The second Own Address register.
+pub struct OA2 {
+    /// The address.
+    pub addr: u8,
+    /// The bit mask that will affect how the own address 2 register is compared.
+    pub mask: AddrMask,
+}
+
+#[derive(Copy, Clone)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+/// The Own Address(es) of the I2C peripheral.
+pub enum OwnAddresses {
+    /// Configuration for only the OA1 register.
+    OA1(Address),
+    /// Configuration for only the OA2 register.
+    OA2(OA2),
+    /// Configuration for both the OA1 and OA2 registers.
+    Both {
+        /// The [Address] for the OA1 register.
+        oa1: Address,
+        /// The [OA2] configuration.
+        oa2: OA2,
+    },
+}
+
+/// Slave Configuration
+#[derive(Copy, Clone)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub struct SlaveAddrConfig {
+    /// Target Address(es)
+    pub addr: OwnAddresses,
+    /// Control if the peripheral should respond to the general call address
+    pub general_call: bool,
+}
+impl SlaveAddrConfig {
+    /// Create a new slave address configuration with only the OA1 register set in 7 bit mode and the general call disabled.
+    pub fn basic(addr: u8) -> Self {
+        Self {
+            addr: OwnAddresses::OA1(Address::SevenBit(addr)),
+            general_call: false,
+        }
+    }
+}
+
+/// I2C config
+#[non_exhaustive]
+#[derive(Copy, Clone)]
+pub struct Config {
+    /// Enable internal pullup on SDA.
+    ///
+    /// Using external pullup resistors is recommended for I2C. If you do
+    /// have external pullups you should not enable this.
+    #[cfg(gpio_v2)]
+    pub sda_pullup: bool,
+    /// Enable internal pullup on SCL.
+    ///
+    /// Using external pullup resistors is recommended for I2C. If you do
+    /// have external pullups you should not enable this.
+    #[cfg(gpio_v2)]
+    pub scl_pullup: bool,
+    /// Timeout.
+    #[cfg(feature = "time")]
+    pub timeout: embassy_time::Duration,
+}
+
+impl Default for Config {
+    fn default() -> Self {
+        Self {
+            #[cfg(gpio_v2)]
+            sda_pullup: false,
+            #[cfg(gpio_v2)]
+            scl_pullup: false,
+            #[cfg(feature = "time")]
+            timeout: embassy_time::Duration::from_millis(1000),
+        }
+    }
+}
+
+impl Config {
+    pub(super) fn scl_af(&self) -> AfType {
+        #[cfg(gpio_v1)]
+        return AfType::output(OutputType::OpenDrain, Speed::Medium);
+        #[cfg(gpio_v2)]
+        return AfType::output_pull(
+            OutputType::OpenDrain,
+            Speed::Medium,
+            match self.scl_pullup {
+                true => Pull::Up,
+                false => Pull::Down,
+            },
+        );
+    }
+
+    pub(super) fn sda_af(&self) -> AfType {
+        #[cfg(gpio_v1)]
+        return AfType::output(OutputType::OpenDrain, Speed::Medium);
+        #[cfg(gpio_v2)]
+        return AfType::output_pull(
+            OutputType::OpenDrain,
+            Speed::Medium,
+            match self.sda_pullup {
+                true => Pull::Up,
+                false => Pull::Down,
+            },
+        );
+    }
+}