xref: /linux/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_pll.c (revision 75bf465f0bc33e9b776a46d6a1b9b990f5fb7c37)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 Red Hat
4  * Author: Rob Clark <robdclark@gmail.com>
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/clk-provider.h>
9 
10 #include "mdp4_kms.h"
11 
12 struct mdp4_lvds_pll {
13 	struct clk_hw pll_hw;
14 	struct drm_device *dev;
15 	unsigned long pixclk;
16 };
17 #define to_mdp4_lvds_pll(x) container_of(x, struct mdp4_lvds_pll, pll_hw)
18 
get_kms(struct mdp4_lvds_pll * lvds_pll)19 static struct mdp4_kms *get_kms(struct mdp4_lvds_pll *lvds_pll)
20 {
21 	struct msm_drm_private *priv = lvds_pll->dev->dev_private;
22 	return to_mdp4_kms(to_mdp_kms(priv->kms));
23 }
24 
25 struct pll_rate {
26 	unsigned long rate;
27 	struct {
28 		uint32_t val;
29 		uint32_t reg;
30 	} conf[32];
31 };
32 
33 /* NOTE: keep sorted highest freq to lowest: */
34 static const struct pll_rate freqtbl[] = {
35 	{ 72000000, {
36 		{ 0x8f, REG_MDP4_LVDS_PHY_PLL_CTRL_1 },
37 		{ 0x30, REG_MDP4_LVDS_PHY_PLL_CTRL_2 },
38 		{ 0xc6, REG_MDP4_LVDS_PHY_PLL_CTRL_3 },
39 		{ 0x10, REG_MDP4_LVDS_PHY_PLL_CTRL_5 },
40 		{ 0x07, REG_MDP4_LVDS_PHY_PLL_CTRL_6 },
41 		{ 0x62, REG_MDP4_LVDS_PHY_PLL_CTRL_7 },
42 		{ 0x41, REG_MDP4_LVDS_PHY_PLL_CTRL_8 },
43 		{ 0x0d, REG_MDP4_LVDS_PHY_PLL_CTRL_9 },
44 		{ 0, 0 } }
45 	},
46 };
47 
find_rate(unsigned long rate)48 static const struct pll_rate *find_rate(unsigned long rate)
49 {
50 	int i;
51 	for (i = 1; i < ARRAY_SIZE(freqtbl); i++)
52 		if (rate > freqtbl[i].rate)
53 			return &freqtbl[i-1];
54 	return &freqtbl[i-1];
55 }
56 
mpd4_lvds_pll_enable(struct clk_hw * hw)57 static int mpd4_lvds_pll_enable(struct clk_hw *hw)
58 {
59 	struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
60 	struct mdp4_kms *mdp4_kms = get_kms(lvds_pll);
61 	const struct pll_rate *pll_rate = find_rate(lvds_pll->pixclk);
62 	int i;
63 
64 	DBG("pixclk=%lu (%lu)", lvds_pll->pixclk, pll_rate->rate);
65 
66 	if (WARN_ON(!pll_rate))
67 		return -EINVAL;
68 
69 	mdp4_write(mdp4_kms, REG_MDP4_LCDC_LVDS_PHY_RESET, 0x33);
70 
71 	for (i = 0; pll_rate->conf[i].reg; i++)
72 		mdp4_write(mdp4_kms, pll_rate->conf[i].reg, pll_rate->conf[i].val);
73 
74 	mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_CTRL_0, 0x01);
75 
76 	/* Wait until LVDS PLL is locked and ready */
77 	while (!mdp4_read(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_LOCKED))
78 		cpu_relax();
79 
80 	return 0;
81 }
82 
mpd4_lvds_pll_disable(struct clk_hw * hw)83 static void mpd4_lvds_pll_disable(struct clk_hw *hw)
84 {
85 	struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
86 	struct mdp4_kms *mdp4_kms = get_kms(lvds_pll);
87 
88 	DBG("");
89 
90 	mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_CFG0, 0x0);
91 	mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_CTRL_0, 0x0);
92 }
93 
mpd4_lvds_pll_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)94 static unsigned long mpd4_lvds_pll_recalc_rate(struct clk_hw *hw,
95 				unsigned long parent_rate)
96 {
97 	struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
98 	return lvds_pll->pixclk;
99 }
100 
mpd4_lvds_pll_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)101 static long mpd4_lvds_pll_round_rate(struct clk_hw *hw, unsigned long rate,
102 		unsigned long *parent_rate)
103 {
104 	const struct pll_rate *pll_rate = find_rate(rate);
105 	return pll_rate->rate;
106 }
107 
mpd4_lvds_pll_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)108 static int mpd4_lvds_pll_set_rate(struct clk_hw *hw, unsigned long rate,
109 		unsigned long parent_rate)
110 {
111 	struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
112 	lvds_pll->pixclk = rate;
113 	return 0;
114 }
115 
116 
117 static const struct clk_ops mpd4_lvds_pll_ops = {
118 	.enable = mpd4_lvds_pll_enable,
119 	.disable = mpd4_lvds_pll_disable,
120 	.recalc_rate = mpd4_lvds_pll_recalc_rate,
121 	.round_rate = mpd4_lvds_pll_round_rate,
122 	.set_rate = mpd4_lvds_pll_set_rate,
123 };
124 
125 static const char *mpd4_lvds_pll_parents[] = {
126 	"pxo",
127 };
128 
129 static struct clk_init_data pll_init = {
130 	.name = "mpd4_lvds_pll",
131 	.ops = &mpd4_lvds_pll_ops,
132 	.parent_names = mpd4_lvds_pll_parents,
133 	.num_parents = ARRAY_SIZE(mpd4_lvds_pll_parents),
134 };
135 
mpd4_lvds_pll_init(struct drm_device * dev)136 struct clk *mpd4_lvds_pll_init(struct drm_device *dev)
137 {
138 	struct mdp4_lvds_pll *lvds_pll;
139 	struct clk *clk;
140 	int ret;
141 
142 	lvds_pll = devm_kzalloc(dev->dev, sizeof(*lvds_pll), GFP_KERNEL);
143 	if (!lvds_pll) {
144 		ret = -ENOMEM;
145 		goto fail;
146 	}
147 
148 	lvds_pll->dev = dev;
149 
150 	lvds_pll->pll_hw.init = &pll_init;
151 	clk = devm_clk_register(dev->dev, &lvds_pll->pll_hw);
152 	if (IS_ERR(clk)) {
153 		ret = PTR_ERR(clk);
154 		goto fail;
155 	}
156 
157 	return clk;
158 
159 fail:
160 	return ERR_PTR(ret);
161 }
162