1/* SPDX-License-Identifier: GPL-2.0+ */
2/*
3 * Copyright (C) 2023 Loongson Technology Corporation Limited
4 */
5
6#ifndef __LSDC_PIXPLL_H__
7#define __LSDC_PIXPLL_H__
8
9#include <drm/drm_device.h>
10
11/*
12 * Loongson Pixel PLL hardware structure
13 *
14 * refclk: reference frequency, 100 MHz from external oscillator
15 * outclk: output frequency desired.
16 *
17 *
18 * L1 Fref Fvco L2
19 * refclk +-----------+ +------------------+ +---------+ outclk
20 * ---+---> | Prescaler | ---> | Clock Multiplier | ---> | divider | -------->
21 * | +-----------+ +------------------+ +---------+ ^
22 * | ^ ^ ^ |
23 * | | | | |
24 * | | | | |
25 * | div_ref loopc div_out |
26 * | |
27 * +---- bypass (bypass above software configurable clock if set) ----+
28 *
29 * outclk = refclk / div_ref * loopc / div_out;
30 *
31 * sel_out: PLL clock output selector(enable).
32 *
33 * If sel_out == 1, then enable output clock (turn On);
34 * If sel_out == 0, then disable output clock (turn Off);
35 *
36 * PLL working requirements:
37 *
38 * 1) 20 MHz <= refclk / div_ref <= 40Mhz
39 * 2) 1.2 GHz <= refclk /div_out * loopc <= 3.2 Ghz
40 */
41
42struct lsdc_pixpll_parms {
43 unsigned int ref_clock;
44 unsigned int div_ref;
45 unsigned int loopc;
46 unsigned int div_out;
47};
48
49struct lsdc_pixpll;
50
51struct lsdc_pixpll_funcs {
52 int (*setup)(struct lsdc_pixpll * const this);
53
54 int (*compute)(struct lsdc_pixpll * const this,
55 unsigned int clock,
56 struct lsdc_pixpll_parms *pout);
57
58 int (*update)(struct lsdc_pixpll * const this,
59 struct lsdc_pixpll_parms const *pin);
60
61 unsigned int (*get_rate)(struct lsdc_pixpll * const this);
62
63 void (*print)(struct lsdc_pixpll * const this,
64 struct drm_printer *printer);
65};
66
67struct lsdc_pixpll {
68 const struct lsdc_pixpll_funcs *funcs;
69
70 struct drm_device *ddev;
71
72 /* PLL register offset */
73 u32 reg_base;
74 /* PLL register size in bytes */
75 u32 reg_size;
76
77 void __iomem *mmio;
78
79 struct lsdc_pixpll_parms *priv;
80};
81
82int lsdc_pixpll_init(struct lsdc_pixpll * const this,
83 struct drm_device *ddev,
84 unsigned int index);
85
86#endif
87

source code of linux/drivers/gpu/drm/loongson/lsdc_pixpll.h