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// Copyright 2022 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef SRC_GRAPHICS_DISPLAY_DRIVERS_INTEL_I915_CLOCK_CDCLK_H_
#define SRC_GRAPHICS_DISPLAY_DRIVERS_INTEL_I915_CLOCK_CDCLK_H_
#include <lib/mmio/mmio-buffer.h>
#include <lib/mmio/mmio.h>
#include <zircon/assert.h>
namespace i915 {
class CoreDisplayClock {
public:
CoreDisplayClock() = default;
virtual ~CoreDisplayClock() = default;
// Returns true if the target CDCLK frequency |freq_khz| is supported by the
// current platform and current hardware config.
virtual bool CheckFrequency(uint32_t freq_khz) = 0;
// Sets CDCLK frequency to |freq_khz|, if the frequency is supported by the
// current hardware config.
// Returns false if there's any error when setting the frequency; otherwise
// returns true.
virtual bool SetFrequency(uint32_t freq_khz) = 0;
uint32_t current_freq_khz() const { return current_freq_khz_; }
protected:
virtual bool LoadState() = 0;
void set_current_freq_khz(uint32_t freq_khz) { current_freq_khz_ = freq_khz; }
private:
uint32_t current_freq_khz_ = 0u;
};
// Skylake CD Clock
class SklCoreDisplayClock final : public CoreDisplayClock {
public:
explicit SklCoreDisplayClock(fdf::MmioBuffer* mmio_space);
~SklCoreDisplayClock() override = default;
bool CheckFrequency(uint32_t freq_khz) override;
bool SetFrequency(uint32_t freq_khz) override;
private:
bool LoadState() override;
bool PreChangeFreq();
bool ChangeFreq(uint32_t freq_khz);
bool PostChangeFreq(uint32_t freq_khz);
static uint32_t FreqToVoltageLevel(uint32_t freq_khz);
fdf::MmioBuffer* mmio_space_ = nullptr;
};
// Tiger Lake CD Clock
class TglCoreDisplayClock final : public CoreDisplayClock {
public:
explicit TglCoreDisplayClock(fdf::MmioBuffer* mmio_space);
~TglCoreDisplayClock() override = default;
// Clients could set |freq_khz| to 0 to disable the CDCLK PLL, or
// set it to a non-zero value to enable the PLL; |freq_khz| should
// match the device's reference clock frequency (see
// intel-gfx-prm-osrc-tgl-vol12-displayengine_0.pdf P178).
bool CheckFrequency(uint32_t freq_khz) override;
bool SetFrequency(uint32_t freq_khz) override;
private:
struct State {
uint32_t cd2x_divider = 1;
uint32_t pll_ratio = 1;
};
std::optional<State> FreqToState(uint32_t freq_khz) const;
bool LoadState() override;
bool PreChangeFreq();
bool ChangeFreq(uint32_t freq_khz);
bool PostChangeFreq(uint32_t freq_khz);
static uint32_t FreqToVoltageLevel(uint32_t freq_khz);
bool Disable();
bool Enable(uint32_t freq_khz, State state);
fdf::MmioBuffer* mmio_space_ = nullptr;
uint32_t ref_clock_khz_ = 0;
State state_ = {};
bool enabled_ = false;
};
} // namespace i915
#endif // SRC_GRAPHICS_DISPLAY_DRIVERS_INTEL_I915_CLOCK_CDCLK_H_