[PATCH v8 2/2] platform: Add initial synology microp driver

[Markus Probst <markus.probst@posteo.de>]

Add a initial synology microp driver, written in Rust.
The driver targets a microcontroller found in Synology NAS devices. It
currently only supports controlling of the power led, status led, alert
led and usb led. Other components such as fan control or handling
on-device buttons will be added once the required rust abstractions are
there.

This driver can be used both on arm and x86, thus it goes into the root
directory of drivers/platform.

Tested successfully on a Synology DS923+.

Signed-off-by: Markus Probst <markus.probst@posteo.de>
---
 MAINTAINERS                                        |   6 +
 drivers/platform/Kconfig                           |   2 +
 drivers/platform/Makefile                          |   1 +
 drivers/platform/synology_microp/Kconfig           |  13 +
 drivers/platform/synology_microp/Makefile          |   3 +
 drivers/platform/synology_microp/TODO              |   7 +
 drivers/platform/synology_microp/command.rs        |  54 ++++
 drivers/platform/synology_microp/led.rs            | 281 +++++++++++++++++++++
 drivers/platform/synology_microp/model.rs          |  49 ++++
 .../platform/synology_microp/synology_microp.rs    | 110 ++++++++
 10 files changed, 526 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index c1c686846cdd..49f08290eed0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25555,6 +25555,12 @@ F:	drivers/dma-buf/sync_*
 F:	include/linux/sync_file.h
 F:	include/uapi/linux/sync_file.h
 
+SYNOLOGY MICROP DRIVER
+M:	Markus Probst <markus.probst@posteo.de>
+S:	Maintained
+F:	Documentation/devicetree/bindings/embedded-controller/synology,ds1825p-microp.yaml
+F:	drivers/platform/synology_microp/
+
 SYNOPSYS ARC ARCHITECTURE
 M:	Vineet Gupta <vgupta@kernel.org>
 L:	linux-snps-arc@lists.infradead.org
diff --git a/drivers/platform/Kconfig b/drivers/platform/Kconfig
index 312788f249c9..996050566a4a 100644
--- a/drivers/platform/Kconfig
+++ b/drivers/platform/Kconfig
@@ -22,3 +22,5 @@ source "drivers/platform/arm64/Kconfig"
 source "drivers/platform/raspberrypi/Kconfig"
 
 source "drivers/platform/wmi/Kconfig"
+
+source "drivers/platform/synology_microp/Kconfig"
diff --git a/drivers/platform/Makefile b/drivers/platform/Makefile
index fa322e7f8716..2381872e9133 100644
--- a/drivers/platform/Makefile
+++ b/drivers/platform/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_SURFACE_PLATFORMS)	+= surface/
 obj-$(CONFIG_ARM64_PLATFORM_DEVICES)	+= arm64/
 obj-$(CONFIG_BCM2835_VCHIQ)	+= raspberrypi/
 obj-$(CONFIG_ACPI_WMI)		+= wmi/
+obj-$(CONFIG_SYNOLOGY_MICROP)	+= synology_microp/
diff --git a/drivers/platform/synology_microp/Kconfig b/drivers/platform/synology_microp/Kconfig
new file mode 100644
index 000000000000..7c4d8f2808f0
--- /dev/null
+++ b/drivers/platform/synology_microp/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config SYNOLOGY_MICROP
+	tristate "Synology Microp driver"
+	depends on LEDS_CLASS && LEDS_CLASS_MULTICOLOR
+	depends on RUST_SERIAL_DEV_BUS_ABSTRACTIONS
+	help
+	  Enable support for the MCU found in Synology NAS devices.
+
+	  This is needed to properly shutdown and reboot the device, as well as
+	  additional functionality like fan and LED control.
+
+	  This driver is work in progress and may not be fully functional.
diff --git a/drivers/platform/synology_microp/Makefile b/drivers/platform/synology_microp/Makefile
new file mode 100644
index 000000000000..63585ccf76e4
--- /dev/null
+++ b/drivers/platform/synology_microp/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-y += synology_microp.o
diff --git a/drivers/platform/synology_microp/TODO b/drivers/platform/synology_microp/TODO
new file mode 100644
index 000000000000..1961a33115db
--- /dev/null
+++ b/drivers/platform/synology_microp/TODO
@@ -0,0 +1,7 @@
+TODO:
+- add missing components:
+  - handle on-device buttons (Power, Factory reset, "USB Copy")
+  - handle fan failure
+  - beeper
+  - fan speed control
+  - correctly perform device power-off and restart on Synology devices
diff --git a/drivers/platform/synology_microp/command.rs b/drivers/platform/synology_microp/command.rs
new file mode 100644
index 000000000000..430cb858e1c3
--- /dev/null
+++ b/drivers/platform/synology_microp/command.rs
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    device::Bound,
+    error::Result,
+    serdev, //
+};
+
+use crate::led;
+
+#[expect(
+    clippy::enum_variant_names,
+    reason = "future variants will not end with Led"
+)]
+pub(crate) enum Command {
+    PowerLed(led::State),
+    StatusLed(led::StatusLedColor, led::State),
+    AlertLed(led::State),
+    UsbLed(led::State),
+    EsataLed(led::State),
+}
+
+impl Command {
+    pub(crate) fn write(self, dev: &serdev::Device<Bound>) -> Result {
+        dev.write_all(
+            match self {
+                Self::PowerLed(led::State::On) => &[0x34],
+                Self::PowerLed(led::State::Blink) => &[0x35],
+                Self::PowerLed(led::State::Off) => &[0x36],
+
+                Self::StatusLed(_, led::State::Off) => &[0x37],
+                Self::StatusLed(led::StatusLedColor::Green, led::State::On) => &[0x38],
+                Self::StatusLed(led::StatusLedColor::Green, led::State::Blink) => &[0x39],
+                Self::StatusLed(led::StatusLedColor::Orange, led::State::On) => &[0x3A],
+                Self::StatusLed(led::StatusLedColor::Orange, led::State::Blink) => &[0x3B],
+
+                Self::AlertLed(led::State::On) => &[0x4C, 0x41, 0x31],
+                Self::AlertLed(led::State::Blink) => &[0x4C, 0x41, 0x32],
+                Self::AlertLed(led::State::Off) => &[0x4C, 0x41, 0x33],
+
+                Self::UsbLed(led::State::On) => &[0x40],
+                Self::UsbLed(led::State::Blink) => &[0x41],
+                Self::UsbLed(led::State::Off) => &[0x42],
+
+                Self::EsataLed(led::State::On) => &[0x4C, 0x45, 0x31],
+                Self::EsataLed(led::State::Blink) => &[0x4C, 0x45, 0x32],
+                Self::EsataLed(led::State::Off) => &[0x4C, 0x45, 0x33],
+            },
+            serdev::Timeout::Max,
+        )?;
+        dev.wait_until_sent(serdev::Timeout::Max);
+        Ok(())
+    }
+}
diff --git a/drivers/platform/synology_microp/led.rs b/drivers/platform/synology_microp/led.rs
new file mode 100644
index 000000000000..f89998a7e6b4
--- /dev/null
+++ b/drivers/platform/synology_microp/led.rs
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::{
+    device::Bound,
+    devres::{
+        self,
+        Devres, //
+    },
+    led::{
+        self,
+        LedOps,
+        MultiColorSubLed, //
+    },
+    new_mutex,
+    prelude::*,
+    serdev,
+    str::CString,
+    sync::Mutex, //
+};
+use pin_init::pin_init_scope;
+
+use crate::{
+    command::Command,
+    model::Model, //
+};
+
+#[pin_data]
+pub(crate) struct Data {
+    #[pin]
+    status: Devres<led::MultiColorDevice<StatusLedHandler>>,
+    power_name: CString,
+    #[pin]
+    power: Devres<led::Device<LedHandler>>,
+}
+
+impl Data {
+    pub(super) fn register<'a>(
+        dev: &'a serdev::Device<Bound>,
+        model: &'a Model,
+    ) -> impl PinInit<Self, Error> + 'a {
+        pin_init_scope(move || {
+            if let Some(color) = model.led_alert {
+                let name = CString::try_from_fmt(fmt!("{}:alarm", color.as_c_str().to_str()?))?;
+                devres::register(
+                    dev.as_ref(),
+                    led::DeviceBuilder::new().color(color).name(&name).build(
+                        dev,
+                        try_pin_init!(LedHandler {
+                            blink <- new_mutex!(false),
+                            command: Command::AlertLed,
+                        }),
+                    ),
+                    GFP_KERNEL,
+                )?;
+            }
+
+            if model.led_usb_copy {
+                devres::register(
+                    dev.as_ref(),
+                    led::DeviceBuilder::new()
+                        .color(led::Color::Green)
+                        .name(c"green:usb")
+                        .build(
+                            dev,
+                            try_pin_init!(LedHandler {
+                                blink <- new_mutex!(false),
+                                command: Command::UsbLed,
+                            }),
+                        ),
+                    GFP_KERNEL,
+                )?;
+            }
+
+            if model.led_esata {
+                devres::register(
+                    dev.as_ref(),
+                    led::DeviceBuilder::new()
+                        .color(led::Color::Green)
+                        .name(c"green:esata")
+                        .build(
+                            dev,
+                            try_pin_init!(LedHandler {
+                                blink <- new_mutex!(false),
+                                command: Command::EsataLed,
+                            }),
+                        ),
+                    GFP_KERNEL,
+                )?;
+            }
+
+            Ok(try_pin_init!(Self {
+                status <- led::DeviceBuilder::new()
+                    .color(led::Color::Multi)
+                    .name(c"multicolor:status")
+                    .build_multicolor(
+                        dev,
+                        try_pin_init!(StatusLedHandler {
+                            blink <- new_mutex!(false),
+                        }),
+                        StatusLedHandler::SUBLEDS,
+                    ),
+                power_name: CString::try_from_fmt(fmt!(
+                    "{}:power",
+                    model.led_power.as_c_str().to_str()?
+                ))?,
+                power <- led::DeviceBuilder::new()
+                    .color(model.led_power)
+                    .name(power_name)
+                    .build(
+                        dev,
+                        try_pin_init!(LedHandler {
+                            blink <- new_mutex!(true),
+                            command: Command::PowerLed,
+                        }),
+                    ),
+            }))
+        })
+    }
+}
+
+#[derive(Copy, Clone)]
+pub(crate) enum StatusLedColor {
+    Green,
+    Orange,
+}
+
+#[derive(Copy, Clone)]
+pub(crate) enum State {
+    On,
+    Blink,
+    Off,
+}
+
+#[pin_data]
+struct LedHandler {
+    #[pin]
+    blink: Mutex<bool>,
+    command: fn(State) -> Command,
+}
+
+/// Blink delay measured using video recording on DS923+ for Power and Status Led.
+///
+/// We assume it is the same for all other leds and models.
+const BLINK_DELAY: usize = 167;
+
+#[vtable]
+impl LedOps for LedHandler {
+    type Bus = serdev::Device<Bound>;
+    type Mode = led::Normal;
+    const BLOCKING: bool = true;
+    const MAX_BRIGHTNESS: u32 = 1;
+
+    fn brightness_set(
+        &self,
+        dev: &Self::Bus,
+        _classdev: &led::Device<Self>,
+        brightness: u32,
+    ) -> Result<()> {
+        let mut blink = self.blink.lock();
+        (self.command)(if brightness == 0 {
+            *blink = false;
+            State::Off
+        } else if *blink {
+            State::Blink
+        } else {
+            State::On
+        })
+        .write(dev)?;
+
+        Ok(())
+    }
+
+    fn blink_set(
+        &self,
+        dev: &Self::Bus,
+        _classdev: &led::Device<Self>,
+        delay_on: &mut usize,
+        delay_off: &mut usize,
+    ) -> Result<()> {
+        let mut blink = self.blink.lock();
+
+        (self.command)(if *delay_on == 0 && *delay_off != 0 {
+            State::Off
+        } else if *delay_on != 0 && *delay_off == 0 {
+            State::On
+        } else {
+            *blink = true;
+            *delay_on = BLINK_DELAY;
+            *delay_off = BLINK_DELAY;
+
+            State::Blink
+        })
+        .write(dev)
+    }
+}
+
+#[pin_data]
+struct StatusLedHandler {
+    #[pin]
+    blink: Mutex<bool>,
+}
+
+impl StatusLedHandler {
+    const SUBLEDS: &[MultiColorSubLed] = &[
+        MultiColorSubLed::new(led::Color::Green).initial_intensity(1),
+        MultiColorSubLed::new(led::Color::Orange),
+    ];
+}
+
+#[vtable]
+impl LedOps for StatusLedHandler {
+    type Bus = serdev::Device<Bound>;
+    type Mode = led::MultiColor;
+    const BLOCKING: bool = true;
+    const MAX_BRIGHTNESS: u32 = 1;
+
+    fn brightness_set(
+        &self,
+        dev: &Self::Bus,
+        classdev: &led::MultiColorDevice<Self>,
+        brightness: u32,
+    ) -> Result<()> {
+        let mut blink = self.blink.lock();
+        if brightness == 0 {
+            *blink = false;
+        }
+
+        let (color, subled_brightness) = if classdev.subleds()[1].intensity == 0 {
+            (StatusLedColor::Green, classdev.subleds()[0].brightness)
+        } else {
+            (StatusLedColor::Orange, classdev.subleds()[1].brightness)
+        };
+
+        Command::StatusLed(
+            color,
+            if subled_brightness == 0 {
+                State::Off
+            } else if *blink {
+                State::Blink
+            } else {
+                State::On
+            },
+        )
+        .write(dev)
+    }
+
+    fn blink_set(
+        &self,
+        dev: &Self::Bus,
+        classdev: &led::MultiColorDevice<Self>,
+        delay_on: &mut usize,
+        delay_off: &mut usize,
+    ) -> Result<()> {
+        let mut blink = self.blink.lock();
+        *blink = true;
+
+        let (color, subled_intensity) = if classdev.subleds()[1].intensity == 0 {
+            (StatusLedColor::Green, classdev.subleds()[0].intensity)
+        } else {
+            (StatusLedColor::Orange, classdev.subleds()[1].intensity)
+        };
+        Command::StatusLed(
+            color,
+            if *delay_on == 0 && *delay_off != 0 {
+                *blink = false;
+                State::Off
+            } else if subled_intensity == 0 {
+                State::Off
+            } else if *delay_on != 0 && *delay_off == 0 {
+                *blink = false;
+                State::On
+            } else {
+                *delay_on = BLINK_DELAY;
+                *delay_off = BLINK_DELAY;
+
+                State::Blink
+            },
+        )
+        .write(dev)
+    }
+}
diff --git a/drivers/platform/synology_microp/model.rs b/drivers/platform/synology_microp/model.rs
new file mode 100644
index 000000000000..715d8840f56b
--- /dev/null
+++ b/drivers/platform/synology_microp/model.rs
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+
+use kernel::led::Color;
+
+pub(crate) struct Model {
+    pub(crate) led_power: Color,
+    pub(crate) led_alert: Option<Color>,
+    pub(crate) led_usb_copy: bool,
+    pub(crate) led_esata: bool,
+}
+
+impl Model {
+    pub(super) const fn new() -> Self {
+        Self {
+            led_power: Color::Blue,
+            led_alert: None,
+            led_usb_copy: false,
+            led_esata: false,
+        }
+    }
+
+    pub(super) const fn led_power(self, color: Color) -> Self {
+        Self {
+            led_power: color,
+            ..self
+        }
+    }
+
+    pub(super) const fn led_alert(self, color: Color) -> Self {
+        Self {
+            led_alert: Some(color),
+            ..self
+        }
+    }
+
+    pub(super) const fn led_esata(self) -> Self {
+        Self {
+            led_esata: true,
+            ..self
+        }
+    }
+
+    pub(super) const fn led_usb_copy(self) -> Self {
+        Self {
+            led_usb_copy: true,
+            ..self
+        }
+    }
+}
diff --git a/drivers/platform/synology_microp/synology_microp.rs b/drivers/platform/synology_microp/synology_microp.rs
new file mode 100644
index 000000000000..1fd4fc658d85
--- /dev/null
+++ b/drivers/platform/synology_microp/synology_microp.rs
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Synology Microp driver
+
+use kernel::{
+    device,
+    led::Color,
+    of::{
+        DeviceId,
+        IdTable, //
+    },
+    of_device_table,
+    prelude::*,
+    serdev, //
+};
+use pin_init::pin_init_scope;
+
+use crate::model::Model;
+
+pub(crate) mod command;
+mod led;
+mod model;
+
+kernel::module_serdev_device_driver! {
+    type: SynologyMicropDriver,
+    name: "synology_microp",
+    authors: ["Markus Probst <markus.probst@posteo.de>"],
+    description: "Synology Microp driver",
+    license: "GPL v2",
+}
+
+#[rustfmt::skip]
+of_device_table!(
+    OF_TABLE,
+    MODULE_OF_TABLE,
+    Model,
+    [
+        // apollolake
+        (DeviceId::new(c"synology,ds918p-microp"), Model::new()),
+
+        // evansport
+        (DeviceId::new(c"synology,ds214play-microp"), Model::new()),
+
+        // geminilakenk
+        (DeviceId::new(c"synology,ds225p-microp"), Model::new().led_usb_copy()),
+        (DeviceId::new(c"synology,ds425p-microp"), Model::new()),
+
+        // pineview
+        (DeviceId::new(c"synology,ds710p-microp"), Model::new().led_esata()),
+        (DeviceId::new(c"synology,ds1010p-microp"), Model::new().led_alert(Color::Orange)),
+        (DeviceId::new(c"synology,ds411p-microp"), Model::new()),
+
+        // r1000
+        (DeviceId::new(c"synology,ds923p-microp"), Model::new()),
+        (DeviceId::new(c"synology,ds723p-microp"), Model::new()),
+        (DeviceId::new(c"synology,ds1522p-microp"), Model::new()),
+        (DeviceId::new(c"synology,rs422p-microp"), Model::new().led_power(Color::Green)),
+
+        // r1000nk
+        (DeviceId::new(c"synology,ds725p-microp"), Model::new()),
+
+        // rtd1296
+        (DeviceId::new(c"synology,ds118-microp"), Model::new()),
+
+        // rtd1619b
+        (DeviceId::new(c"synology,ds124-microp"), Model::new()),
+        (DeviceId::new(c"synolody,ds223-microp"), Model::new().led_usb_copy()),
+        (DeviceId::new(c"synology,ds223j-microp"), Model::new()),
+
+        // v1000
+        (DeviceId::new(c"synology,ds1823xsp-microp"), Model::new()),
+        (DeviceId::new(c"synology,rs822p-microp"), Model::new().led_power(Color::Green)),
+        (DeviceId::new(c"synology,rs1221p-microp"), Model::new().led_power(Color::Green)),
+        (DeviceId::new(c"synology,rs1221rpp-microp"), Model::new().led_power(Color::Green)),
+
+        // v1000nk
+        (DeviceId::new(c"synology,ds925p-microp"), Model::new()),
+        (DeviceId::new(c"synology,ds1525p-microp"), Model::new()),
+        (DeviceId::new(c"synology,ds1825p-microp"), Model::new()),
+    ]
+);
+
+#[pin_data]
+struct SynologyMicropDriver {
+    #[pin]
+    led: led::Data,
+}
+
+#[vtable]
+impl serdev::Driver for SynologyMicropDriver {
+    type IdInfo = Model;
+    const OF_ID_TABLE: Option<IdTable<Self::IdInfo>> = Some(&OF_TABLE);
+
+    fn probe(
+        dev: &serdev::Device<device::Core>,
+        model: Option<&Model>,
+    ) -> impl PinInit<Self, kernel::error::Error> {
+        pin_init_scope(move || {
+            let model = model.ok_or(EINVAL)?;
+
+            dev.set_baudrate(9600).map_err(|_| EINVAL)?;
+            dev.set_flow_control(false);
+            dev.set_parity(serdev::Parity::None)?;
+
+            Ok(try_pin_init!(Self {
+                led <- led::Data::register(dev, model),
+            }))
+        })
+    }
+}

-- 
2.52.0