capsules: i2c_master: Use I2CMux

To allow an I2C bus to have devices created by the board and still be
exposed to userspace let's convert the I2CMasterDriver to use an
I2CDevice instead of a I2C hardware.

This allows muxing an I2C bus with both userspace and devices in the
kernel.

This commit also adds a I2CMasterDriverComponent to help in creating the
I2CMasterDriver.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

boards/apollo3/lora_things_plus/src/main.rs

@@ -44,9 +44,9 @@ use capsules_core::virtualizers::virtual_alarm::MuxAlarm;
 use capsules_core::virtualizers::virtual_alarm::VirtualMuxAlarm;
 use components::bme280::Bme280Component;
 use components::ccs811::Ccs811Component;
+use components::i2c::I2CMasterDriverComponent;
 use kernel::capabilities;
 use kernel::component::Component;
-use kernel::hil::i2c::I2CMaster;
 use kernel::hil::led::LedHigh;
 use kernel::hil::spi::SpiMaster;
 use kernel::hil::time::Counter;
@@ -125,8 +125,10 @@ struct LoRaThingsPlus {
     >,
     gpio: &'static capsules_core::gpio::GPIO<'static, apollo3::gpio::GpioPin<'static>>,
     console: &'static capsules_core::console::Console<'static>,
-    i2c_master:
-        &'static capsules_core::i2c_master::I2CMasterDriver<'static, apollo3::iom::Iom<'static>>,
+    i2c_master: &'static capsules_core::i2c_master::I2CMasterDriver<
+        'static,
+        capsules_core::virtualizers::virtual_i2c::I2CDevice<'static, apollo3::iom::Iom<'static>>,
+    >,
     external_spi_controller: &'static capsules_core::spi_controller::Spi<
         'static,
         capsules_core::virtualizers::virtual_spi::VirtualSpiMasterDevice<
@@ -234,7 +236,6 @@ unsafe fn setup() -> (
 
     // initialize capabilities
     let process_mgmt_cap = create_capability!(capabilities::ProcessManagementCapability);
-    let memory_allocation_cap = create_capability!(capabilities::MemoryAllocationCapability);
 
     let board_kernel = static_init!(kernel::Kernel, kernel::Kernel::new(&PROCESSES));
 
@@ -327,29 +328,16 @@ unsafe fn setup() -> (
     PROCESS_PRINTER = Some(process_printer);
 
     // Init the I2C device attached via Qwiic
-    let i2c_master_buffer = static_init!(
-        [u8; capsules_core::i2c_master::BUFFER_LENGTH],
-        [0; capsules_core::i2c_master::BUFFER_LENGTH]
-    );
-    let i2c_master = static_init!(
-        capsules_core::i2c_master::I2CMasterDriver<'static, apollo3::iom::Iom<'static>>,
-        capsules_core::i2c_master::I2CMasterDriver::new(
-            &peripherals.iom0,
-            i2c_master_buffer,
-            board_kernel.create_grant(
-                capsules_core::i2c_master::DRIVER_NUM,
-                &memory_allocation_cap
-            )
-        )
-    );
-
-    peripherals.iom0.set_master_client(i2c_master);
-    peripherals.iom0.enable();
-
     let mux_i2c = components::i2c::I2CMuxComponent::new(&peripherals.iom0, None).finalize(
         components::i2c_mux_component_static!(apollo3::iom::Iom<'static>),
     );
 
+    let i2c_master =
+        I2CMasterDriverComponent::new(mux_i2c, board_kernel, capsules_core::i2c_master::DRIVER_NUM)
+            .finalize(components::i2c_master_component_static!(
+                apollo3::iom::Iom<'static>
+            ));
+
     let bme280 = Bme280Component::new(mux_i2c, 0x77).finalize(
         components::bme280_component_static!(apollo3::iom::Iom<'static>),
     );

boards/apollo3/redboard_artemis_nano/src/main.rs

@@ -20,9 +20,9 @@ use capsules_core::virtualizers::virtual_alarm::MuxAlarm;
 use capsules_core::virtualizers::virtual_alarm::VirtualMuxAlarm;
 use components::bme280::Bme280Component;
 use components::ccs811::Ccs811Component;
+use components::i2c::I2CMasterDriverComponent;
 use kernel::capabilities;
 use kernel::component::Component;
-use kernel::hil::i2c::I2CMaster;
 use kernel::hil::led::LedHigh;
 use kernel::hil::time::Counter;
 use kernel::platform::{KernelResources, SyscallDriverLookup};
@@ -97,8 +97,10 @@ struct RedboardArtemisNano {
     >,
     gpio: &'static capsules_core::gpio::GPIO<'static, apollo3::gpio::GpioPin<'static>>,
     console: &'static capsules_core::console::Console<'static>,
-    i2c_master:
-        &'static capsules_core::i2c_master::I2CMasterDriver<'static, apollo3::iom::Iom<'static>>,
+    i2c_master: &'static capsules_core::i2c_master::I2CMasterDriver<
+        'static,
+        capsules_core::virtualizers::virtual_i2c::I2CDevice<'static, apollo3::iom::Iom<'static>>,
+    >,
     spi_controller: &'static capsules_core::spi_controller::Spi<
         'static,
         capsules_core::virtualizers::virtual_spi::VirtualSpiMasterDevice<
@@ -196,7 +198,6 @@ unsafe fn setup() -> (
 
     // initialize capabilities
     let process_mgmt_cap = create_capability!(capabilities::ProcessManagementCapability);
-    let memory_allocation_cap = create_capability!(capabilities::MemoryAllocationCapability);
 
     let board_kernel = static_init!(kernel::Kernel, kernel::Kernel::new(&PROCESSES));
 
@@ -289,27 +290,15 @@ unsafe fn setup() -> (
     PROCESS_PRINTER = Some(process_printer);
 
     // Init the I2C device attached via Qwiic
-    let i2c_master_buffer = static_init!(
-        [u8; capsules_core::i2c_master::BUFFER_LENGTH],
-        [0; capsules_core::i2c_master::BUFFER_LENGTH]
+    let mux_i2c = components::i2c::I2CMuxComponent::new(&peripherals.iom2, None).finalize(
+        components::i2c_mux_component_static!(apollo3::iom::Iom<'static>),
     );
-    let i2c_master = static_init!(
-        capsules_core::i2c_master::I2CMasterDriver<'static, apollo3::iom::Iom<'static>>,
-        capsules_core::i2c_master::I2CMasterDriver::new(
-            &peripherals.iom2,
-            i2c_master_buffer,
-            board_kernel.create_grant(
-                capsules_core::i2c_master::DRIVER_NUM,
-                &memory_allocation_cap
-            )
-        )
-    );
-
-    peripherals.iom2.set_master_client(i2c_master);
-    peripherals.iom2.enable();
 
-    let mux_i2c = components::i2c::I2CMuxComponent::new(&peripherals.iom2, None)
-        .finalize(components::i2c_mux_component_static!(apollo3::iom::Iom));
+    let i2c_master =
+        I2CMasterDriverComponent::new(mux_i2c, board_kernel, capsules_core::i2c_master::DRIVER_NUM)
+            .finalize(components::i2c_master_component_static!(
+                apollo3::iom::Iom<'static>
+            ));
 
     let bme280 = Bme280Component::new(mux_i2c, 0x77)
         .finalize(components::bme280_component_static!(apollo3::iom::Iom));

boards/components/src/i2c.rs

@@ -66,6 +66,24 @@ macro_rules! i2c_master_slave_component_static {
     };};
 }
 
+#[macro_export]
+macro_rules! i2c_master_component_static {
+    ($I:ty $(,)?) => {{
+        let i2c_master_buffer = kernel::static_buf!([u8; capsules_core::i2c_master::BUFFER_LENGTH]);
+        let i2c_device =
+            kernel::static_buf!(capsules_core::virtualizers::virtual_i2c::I2CDevice<'static, $I>);
+
+        let driver = kernel::static_buf!(
+            capsules_core::i2c_master::I2CMasterDriver<
+                'static,
+                capsules_core::virtualizers::virtual_i2c::I2CDevice<'static, $I>,
+            >
+        );
+
+        (i2c_device, i2c_master_buffer, driver)
+    };};
+}
+
 pub struct I2CMuxComponent<
     I: 'static + i2c::I2CMaster<'static>,
     S: 'static + i2c::SMBusMaster<'static> = NoSMBus,
@@ -173,3 +191,57 @@ impl<I: 'static + i2c::I2CMasterSlave<'static>> Component for I2CMasterSlaveDriv
         i2c_master_slave_driver
     }
 }
+
+pub struct I2CMasterDriverComponent<I: 'static + i2c::I2CMaster<'static>> {
+    i2c_mux: &'static MuxI2C<'static, I>,
+    board_kernel: &'static kernel::Kernel,
+    driver_num: usize,
+}
+
+impl<I: 'static + i2c::I2CMaster<'static>> I2CMasterDriverComponent<I> {
+    pub fn new(
+        i2c: &'static MuxI2C<'static, I>,
+        board_kernel: &'static kernel::Kernel,
+        driver_num: usize,
+    ) -> Self {
+        I2CMasterDriverComponent {
+            i2c_mux: i2c,
+            board_kernel,
+            driver_num,
+        }
+    }
+}
+
+impl<I: 'static + i2c::I2CMaster<'static>> Component for I2CMasterDriverComponent<I> {
+    type StaticInput = (
+        &'static mut MaybeUninit<I2CDevice<'static, I>>,
+        &'static mut MaybeUninit<[u8; capsules_core::i2c_master::BUFFER_LENGTH]>,
+        &'static mut MaybeUninit<
+            capsules_core::i2c_master::I2CMasterDriver<'static, I2CDevice<'static, I>>,
+        >,
+    );
+    type Output =
+        &'static capsules_core::i2c_master::I2CMasterDriver<'static, I2CDevice<'static, I>>;
+
+    fn finalize(self, static_buffer: Self::StaticInput) -> Self::Output {
+        let grant_cap = create_capability!(capabilities::MemoryAllocationCapability);
+
+        let userspace_device = static_buffer.0.write(I2CDevice::new(self.i2c_mux, 0x00));
+        let i2c_master_buffer = static_buffer
+            .1
+            .write([0; capsules_core::i2c_master::BUFFER_LENGTH]);
+
+        let i2c_master = static_buffer
+            .2
+            .write(capsules_core::i2c_master::I2CMasterDriver::new(
+                userspace_device,
+                i2c_master_buffer,
+                self.board_kernel.create_grant(self.driver_num, &grant_cap),
+            ));
+
+        userspace_device.set_client(i2c_master);
+        i2c::I2CDevice::enable(userspace_device);
+
+        i2c_master
+    }
+}

boards/opentitan/src/main.rs

@@ -20,6 +20,7 @@ use crate::pinmux_layout::BoardPinmuxLayout;
 use capsules_aes_gcm::aes_gcm;
 use capsules_core::virtualizers::virtual_aes_ccm;
 use capsules_core::virtualizers::virtual_alarm::{MuxAlarm, VirtualMuxAlarm};
+use components::i2c::I2CMasterDriverComponent;
 use earlgrey::chip::EarlGreyDefaultPeripherals;
 use earlgrey::chip_config::EarlGreyConfig;
 use earlgrey::pinmux_config::EarlGreyPinmuxConfig;
@@ -28,7 +29,6 @@ use kernel::component::Component;
 use kernel::hil;
 use kernel::hil::entropy::Entropy32;
 use kernel::hil::hasher::Hasher;
-use kernel::hil::i2c::I2CMaster;
 use kernel::hil::led::LedHigh;
 use kernel::hil::rng::Rng;
 use kernel::hil::symmetric_encryption::AES128;
@@ -186,8 +186,10 @@ struct EarlGrey {
         'static,
         capsules_core::virtualizers::virtual_uart::UartDevice<'static>,
     >,
-    i2c_master:
-        &'static capsules_core::i2c_master::I2CMasterDriver<'static, lowrisc::i2c::I2c<'static>>,
+    i2c_master: &'static capsules_core::i2c_master::I2CMasterDriver<
+        'static,
+        capsules_core::virtualizers::virtual_i2c::I2CDevice<'static, lowrisc::i2c::I2c<'static>>,
+    >,
     spi_controller: &'static capsules_core::spi_controller::Spi<
         'static,
         capsules_core::virtualizers::virtual_spi::VirtualSpiMasterDevice<
@@ -522,23 +524,15 @@ unsafe fn setup() -> (
     )
     .finalize(components::hmac_component_static!(lowrisc::hmac::Hmac, 32));
 
-    let i2c_master_buffer = static_init!(
-        [u8; capsules_core::i2c_master::BUFFER_LENGTH],
-        [0; capsules_core::i2c_master::BUFFER_LENGTH]
-    );
-    let i2c_master = static_init!(
-        capsules_core::i2c_master::I2CMasterDriver<'static, lowrisc::i2c::I2c<'static>>,
-        capsules_core::i2c_master::I2CMasterDriver::new(
-            &peripherals.i2c0,
-            i2c_master_buffer,
-            board_kernel.create_grant(
-                capsules_core::i2c_master::DRIVER_NUM,
-                &memory_allocation_cap
-            )
-        )
+    let mux_i2c = components::i2c::I2CMuxComponent::new(&peripherals.i2c0, None).finalize(
+        components::i2c_mux_component_static!(lowrisc::i2c::I2c<'static>),
     );
 
-    peripherals.i2c0.set_master_client(i2c_master);
+    let i2c_master =
+        I2CMasterDriverComponent::new(mux_i2c, board_kernel, capsules_core::i2c_master::DRIVER_NUM)
+            .finalize(components::i2c_master_component_static!(
+                lowrisc::i2c::I2c<'static>
+            ));
 
     //SPI
     let mux_spi = components::spi::SpiMuxComponent::new(&peripherals.spi_host0).finalize(

boards/raspberry_pi_pico/src/main.rs

@@ -12,18 +12,16 @@
 #![cfg_attr(not(doc), no_main)]
 #![deny(missing_docs)]
 
-use core::arch::global_asm;
-
-use capsules_core::i2c_master::I2CMasterDriver;
 use capsules_core::virtualizers::virtual_alarm::VirtualMuxAlarm;
 use components::date_time_component_static;
 use components::gpio::GpioComponent;
+use components::i2c::I2CMasterDriverComponent;
 use components::led::LedsComponent;
+use core::arch::global_asm;
 use enum_primitive::cast::FromPrimitive;
 use kernel::component::Component;
 use kernel::debug;
 use kernel::hil::gpio::{Configure, FloatingState};
-use kernel::hil::i2c::I2CMaster;
 use kernel::hil::led::LedHigh;
 use kernel::hil::usb::Client;
 use kernel::platform::{KernelResources, SyscallDriverLookup};
@@ -88,7 +86,10 @@ pub struct RaspberryPiPico {
     led: &'static capsules_core::led::LedDriver<'static, LedHigh<'static, RPGpioPin<'static>>, 1>,
     adc: &'static capsules_core::adc::AdcVirtualized<'static>,
     temperature: &'static TemperatureDriver,
-    i2c: &'static capsules_core::i2c_master::I2CMasterDriver<'static, I2c<'static, 'static>>,
+    i2c: &'static capsules_core::i2c_master::I2CMasterDriver<
+        'static,
+        capsules_core::virtualizers::virtual_i2c::I2CDevice<'static, I2c<'static, 'static>>,
+    >,
 
     date_time:
         &'static capsules_extra::date_time::DateTimeCapsule<'static, rp2040::rtc::Rtc<'static>>,
@@ -521,24 +522,16 @@ pub unsafe fn main() {
     sda_pin.set_floating_state(FloatingState::PullUp);
     scl_pin.set_floating_state(FloatingState::PullUp);
 
-    let i2c_master_buffer = static_init!(
-        [u8; capsules_core::i2c_master::BUFFER_LENGTH],
-        [0; capsules_core::i2c_master::BUFFER_LENGTH]
-    );
-    let i2c0 = &peripherals.i2c0;
-    let i2c = static_init!(
-        I2CMasterDriver<I2c<'static, 'static>>,
-        I2CMasterDriver::new(
-            i2c0,
-            i2c_master_buffer,
-            board_kernel.create_grant(
-                capsules_core::i2c_master::DRIVER_NUM,
-                &memory_allocation_capability
-            ),
-        )
-    );
-    i2c0.init(10 * 1000);
-    i2c0.set_master_client(i2c);
+    let mux_i2c = components::i2c::I2CMuxComponent::new(&peripherals.i2c0, None)
+        .finalize(components::i2c_mux_component_static!(I2c<'static, 'static>));
+
+    let i2c =
+        I2CMasterDriverComponent::new(mux_i2c, board_kernel, capsules_core::i2c_master::DRIVER_NUM)
+            .finalize(components::i2c_master_component_static!(
+                I2c<'static, 'static>
+            ));
+
+    peripherals.i2c0.init(10 * 1000);
 
     let scheduler = components::sched::round_robin::RoundRobinComponent::new(&PROCESSES)
         .finalize(components::round_robin_component_static!(NUM_PROCS));