linux/drivers/gpu/drm/loongson/lsdc_gfxpll.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2023 Loongson Technology Corporation Limited
 */

#include <linux/delay.h>

#include <drm/drm_file.h>
#include <drm/drm_managed.h>
#include <drm/drm_print.h>

#include "lsdc_drv.h"

/*
 * GFX PLL is the PLL used by DC, GMC and GPU, the structure of the GFX PLL
 * may suffer from change across chip variants.
 *
 *
 *                                            +-------------+  sel_out_dc
 *                                       +----| / div_out_0 | _____/ _____ DC
 *                                       |    +-------------+
 * refclk   +---------+      +-------+   |    +-------------+  sel_out_gmc
 * ---+---> | div_ref | ---> | loopc | --+--> | / div_out_1 | _____/ _____ GMC
 *    |     +---------+      +-------+   |    +-------------+
 *    |          /               *       |    +-------------+  sel_out_gpu
 *    |                                  +----| / div_out_2 | _____/ _____ GPU
 *    |                                       +-------------+
 *    |                                                         ^
 *    |                                                         |
 *    +--------------------------- bypass ----------------------+
 */

struct loongson_gfxpll_bitmap { … };

loongson_gfxpll_reg_bitmap;

static void __gfxpll_rreg(struct loongson_gfxpll *this,
			  union loongson_gfxpll_reg_bitmap *reg)
{ … }

/* Update new parameters to the hardware */

static int loongson_gfxpll_update(struct loongson_gfxpll * const this,
				  struct loongson_gfxpll_parms const *pin)
{ … }

static void loongson_gfxpll_get_rates(struct loongson_gfxpll * const this,
				      unsigned int *dc,
				      unsigned int *gmc,
				      unsigned int *gpu)
{ … }

static void loongson_gfxpll_print(struct loongson_gfxpll * const this,
				  struct drm_printer *p,
				  bool verbose)
{ … }

/* GFX (DC, GPU, GMC) PLL initialization and destroy function */

static void loongson_gfxpll_fini(struct drm_device *ddev, void *data)
{ … }

static int loongson_gfxpll_init(struct loongson_gfxpll * const this)
{ … }

static const struct loongson_gfxpll_funcs lsdc_gmc_gpu_funcs = …;

int loongson_gfxpll_create(struct drm_device *ddev,
			   struct loongson_gfxpll **ppout)
{ … }