linux/drivers/gpu/drm/i915/display/intel_pch_refclk.c

// SPDX-License-Identifier: MIT
/*
 * Copyright © 2021 Intel Corporation
 */

#include "i915_reg.h"
#include "intel_de.h"
#include "intel_display_types.h"
#include "intel_panel.h"
#include "intel_pch_refclk.h"
#include "intel_sbi.h"

static void lpt_fdi_reset_mphy(struct drm_i915_private *dev_priv)
{ … }

/* WaMPhyProgramming:hsw */
static void lpt_fdi_program_mphy(struct drm_i915_private *dev_priv)
{ … }

void lpt_disable_iclkip(struct drm_i915_private *dev_priv)
{ … }

struct iclkip_params { … };

static void iclkip_params_init(struct iclkip_params *p)
{ … }

static int lpt_iclkip_freq(struct iclkip_params *p)
{ … }

static void lpt_compute_iclkip(struct iclkip_params *p, int clock)
{ … }

int lpt_iclkip(const struct intel_crtc_state *crtc_state)
{ … }

/* Program iCLKIP clock to the desired frequency */
void lpt_program_iclkip(const struct intel_crtc_state *crtc_state)
{ … }

int lpt_get_iclkip(struct drm_i915_private *dev_priv)
{ … }

/* Implements 3 different sequences from BSpec chapter "Display iCLK
 * Programming" based on the parameters passed:
 * - Sequence to enable CLKOUT_DP
 * - Sequence to enable CLKOUT_DP without spread
 * - Sequence to enable CLKOUT_DP for FDI usage and configure PCH FDI I/O
 */
static void lpt_enable_clkout_dp(struct drm_i915_private *dev_priv,
				 bool with_spread, bool with_fdi)
{ … }

/* Sequence to disable CLKOUT_DP */
void lpt_disable_clkout_dp(struct drm_i915_private *dev_priv)
{ … }

#define BEND_IDX …

static const u16 sscdivintphase[] = …;

/*
 * Bend CLKOUT_DP
 * steps -50 to 50 inclusive, in steps of 5
 * < 0 slow down the clock, > 0 speed up the clock, 0 == no bend (135MHz)
 * change in clock period = -(steps / 10) * 5.787 ps
 */
static void lpt_bend_clkout_dp(struct drm_i915_private *dev_priv, int steps)
{ … }

#undef BEND_IDX

static bool spll_uses_pch_ssc(struct drm_i915_private *dev_priv)
{ … }

static bool wrpll_uses_pch_ssc(struct drm_i915_private *dev_priv,
			       enum intel_dpll_id id)
{ … }

static void lpt_init_pch_refclk(struct drm_i915_private *dev_priv)
{ … }

static void ilk_init_pch_refclk(struct drm_i915_private *dev_priv)
{ … }

/*
 * Initialize reference clocks when the driver loads
 */
void intel_init_pch_refclk(struct drm_i915_private *dev_priv)
{ … }