Files
linux/drivers/gpu/drm/tyr/driver.rs
Danilo Krummrich 0242623384 rust: driver: let probe() return impl PinInit<Self, Error>
The driver model defines the lifetime of the private data stored in (and
owned by) a bus device to be valid from when the driver is bound to a
device (i.e. from successful probe()) until the driver is unbound from
the device.

This is already taken care of by the Rust implementation of the driver
model. However, we still ask drivers to return a Result<Pin<KBox<Self>>>
from probe().

Unlike in C, where we do not have the concept of initializers, but
rather deal with uninitialized memory, drivers can just return an
impl PinInit<Self, Error> instead.

This contributes to more clarity to the fact that a driver returns it's
device private data in probe() and the Rust driver model owns the data,
manages the lifetime and - considering the lifetime - provides (safe)
accessors for the driver.

Hence, let probe() functions return an impl PinInit<Self, Error> instead
of Result<Pin<KBox<Self>>>.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-10-21 18:40:48 +02:00

206 lines
5.9 KiB
Rust

// SPDX-License-Identifier: GPL-2.0 or MIT
use kernel::c_str;
use kernel::clk::Clk;
use kernel::clk::OptionalClk;
use kernel::device::Bound;
use kernel::device::Core;
use kernel::device::Device;
use kernel::devres::Devres;
use kernel::drm;
use kernel::drm::ioctl;
use kernel::new_mutex;
use kernel::of;
use kernel::platform;
use kernel::prelude::*;
use kernel::regulator;
use kernel::regulator::Regulator;
use kernel::sizes::SZ_2M;
use kernel::sync::Arc;
use kernel::sync::Mutex;
use kernel::time;
use kernel::types::ARef;
use crate::file::File;
use crate::gem::TyrObject;
use crate::gpu;
use crate::gpu::GpuInfo;
use crate::regs;
pub(crate) type IoMem = kernel::io::mem::IoMem<SZ_2M>;
/// Convenience type alias for the DRM device type for this driver.
pub(crate) type TyrDevice = drm::Device<TyrDriver>;
#[pin_data(PinnedDrop)]
pub(crate) struct TyrDriver {
device: ARef<TyrDevice>,
}
#[pin_data(PinnedDrop)]
pub(crate) struct TyrData {
pub(crate) pdev: ARef<platform::Device>,
#[pin]
clks: Mutex<Clocks>,
#[pin]
regulators: Mutex<Regulators>,
/// Some information on the GPU.
///
/// This is mainly queried by userspace, i.e.: Mesa.
pub(crate) gpu_info: GpuInfo,
}
// Both `Clk` and `Regulator` do not implement `Send` or `Sync`, but they
// should. There are patches on the mailing list to address this, but they have
// not landed yet.
//
// For now, add this workaround so that this patch compiles with the promise
// that it will be removed in a future patch.
//
// SAFETY: This will be removed in a future patch.
unsafe impl Send for TyrData {}
// SAFETY: This will be removed in a future patch.
unsafe impl Sync for TyrData {}
fn issue_soft_reset(dev: &Device<Bound>, iomem: &Devres<IoMem>) -> Result {
regs::GPU_CMD.write(dev, iomem, regs::GPU_CMD_SOFT_RESET)?;
// TODO: We cannot poll, as there is no support in Rust currently, so we
// sleep. Change this when read_poll_timeout() is implemented in Rust.
kernel::time::delay::fsleep(time::Delta::from_millis(100));
if regs::GPU_IRQ_RAWSTAT.read(dev, iomem)? & regs::GPU_IRQ_RAWSTAT_RESET_COMPLETED == 0 {
dev_err!(dev, "GPU reset failed with errno\n");
dev_err!(
dev,
"GPU_INT_RAWSTAT is {}\n",
regs::GPU_IRQ_RAWSTAT.read(dev, iomem)?
);
return Err(EIO);
}
Ok(())
}
kernel::of_device_table!(
OF_TABLE,
MODULE_OF_TABLE,
<TyrDriver as platform::Driver>::IdInfo,
[
(of::DeviceId::new(c_str!("rockchip,rk3588-mali")), ()),
(of::DeviceId::new(c_str!("arm,mali-valhall-csf")), ())
]
);
impl platform::Driver for TyrDriver {
type IdInfo = ();
const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
fn probe(
pdev: &platform::Device<Core>,
_info: Option<&Self::IdInfo>,
) -> impl PinInit<Self, Error> {
let core_clk = Clk::get(pdev.as_ref(), Some(c_str!("core")))?;
let stacks_clk = OptionalClk::get(pdev.as_ref(), Some(c_str!("stacks")))?;
let coregroup_clk = OptionalClk::get(pdev.as_ref(), Some(c_str!("coregroup")))?;
core_clk.prepare_enable()?;
stacks_clk.prepare_enable()?;
coregroup_clk.prepare_enable()?;
let mali_regulator = Regulator::<regulator::Enabled>::get(pdev.as_ref(), c_str!("mali"))?;
let sram_regulator = Regulator::<regulator::Enabled>::get(pdev.as_ref(), c_str!("sram"))?;
let request = pdev.io_request_by_index(0).ok_or(ENODEV)?;
let iomem = Arc::pin_init(request.iomap_sized::<SZ_2M>(), GFP_KERNEL)?;
issue_soft_reset(pdev.as_ref(), &iomem)?;
gpu::l2_power_on(pdev.as_ref(), &iomem)?;
let gpu_info = GpuInfo::new(pdev.as_ref(), &iomem)?;
gpu_info.log(pdev);
let platform: ARef<platform::Device> = pdev.into();
let data = try_pin_init!(TyrData {
pdev: platform.clone(),
clks <- new_mutex!(Clocks {
core: core_clk,
stacks: stacks_clk,
coregroup: coregroup_clk,
}),
regulators <- new_mutex!(Regulators {
mali: mali_regulator,
sram: sram_regulator,
}),
gpu_info,
});
let tdev: ARef<TyrDevice> = drm::Device::new(pdev.as_ref(), data)?;
drm::driver::Registration::new_foreign_owned(&tdev, pdev.as_ref(), 0)?;
let driver = TyrDriver { device: tdev };
// We need this to be dev_info!() because dev_dbg!() does not work at
// all in Rust for now, and we need to see whether probe succeeded.
dev_info!(pdev.as_ref(), "Tyr initialized correctly.\n");
Ok(driver)
}
}
#[pinned_drop]
impl PinnedDrop for TyrDriver {
fn drop(self: Pin<&mut Self>) {}
}
#[pinned_drop]
impl PinnedDrop for TyrData {
fn drop(self: Pin<&mut Self>) {
// TODO: the type-state pattern for Clks will fix this.
let clks = self.clks.lock();
clks.core.disable_unprepare();
clks.stacks.disable_unprepare();
clks.coregroup.disable_unprepare();
}
}
// We need to retain the name "panthor" to achieve drop-in compatibility with
// the C driver in the userspace stack.
const INFO: drm::DriverInfo = drm::DriverInfo {
major: 1,
minor: 5,
patchlevel: 0,
name: c_str!("panthor"),
desc: c_str!("ARM Mali Tyr DRM driver"),
};
#[vtable]
impl drm::Driver for TyrDriver {
type Data = TyrData;
type File = File;
type Object = drm::gem::Object<TyrObject>;
const INFO: drm::DriverInfo = INFO;
kernel::declare_drm_ioctls! {
(PANTHOR_DEV_QUERY, drm_panthor_dev_query, ioctl::RENDER_ALLOW, File::dev_query),
}
}
#[pin_data]
struct Clocks {
core: Clk,
stacks: OptionalClk,
coregroup: OptionalClk,
}
#[pin_data]
struct Regulators {
mali: Regulator<regulator::Enabled>,
sram: Regulator<regulator::Enabled>,
}