xref: /openbmc/linux/drivers/clk/meson/vid-pll-div.c (revision c4f7ac64)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018 BayLibre, SAS.
4  * Author: Neil Armstrong <narmstrong@baylibre.com>
5  */
6 
7 #include <linux/clk-provider.h>
8 #include <linux/module.h>
9 
10 #include "clk-regmap.h"
11 #include "vid-pll-div.h"
12 
13 static inline struct meson_vid_pll_div_data *
14 meson_vid_pll_div_data(struct clk_regmap *clk)
15 {
16 	return (struct meson_vid_pll_div_data *)clk->data;
17 }
18 
19 /*
20  * This vid_pll divided is a fully programmable fractionnal divider to
21  * achieve complex video clock rates.
22  *
23  * Here are provided the commonly used fraction values provided by Amlogic.
24  */
25 
26 struct vid_pll_div {
27 	unsigned int shift_val;
28 	unsigned int shift_sel;
29 	unsigned int divider;
30 	unsigned int multiplier;
31 };
32 
33 #define VID_PLL_DIV(_val, _sel, _ft, _fb)				\
34 	{								\
35 		.shift_val = (_val),					\
36 		.shift_sel = (_sel),					\
37 		.divider = (_ft),					\
38 		.multiplier = (_fb),					\
39 	}
40 
41 static const struct vid_pll_div vid_pll_div_table[] = {
42 	VID_PLL_DIV(0x0aaa, 0, 2, 1),	/* 2/1  => /2 */
43 	VID_PLL_DIV(0x5294, 2, 5, 2),	/* 5/2  => /2.5 */
44 	VID_PLL_DIV(0x0db6, 0, 3, 1),	/* 3/1  => /3 */
45 	VID_PLL_DIV(0x36cc, 1, 7, 2),	/* 7/2  => /3.5 */
46 	VID_PLL_DIV(0x6666, 2, 15, 4),	/* 15/4 => /3.75 */
47 	VID_PLL_DIV(0x0ccc, 0, 4, 1),	/* 4/1  => /4 */
48 	VID_PLL_DIV(0x739c, 2, 5, 1),	/* 5/1  => /5 */
49 	VID_PLL_DIV(0x0e38, 0, 6, 1),	/* 6/1  => /6 */
50 	VID_PLL_DIV(0x0000, 3, 25, 4),	/* 25/4 => /6.25 */
51 	VID_PLL_DIV(0x3c78, 1, 7, 1),	/* 7/1  => /7 */
52 	VID_PLL_DIV(0x78f0, 2, 15, 2),	/* 15/2 => /7.5 */
53 	VID_PLL_DIV(0x0fc0, 0, 12, 1),	/* 12/1 => /12 */
54 	VID_PLL_DIV(0x3f80, 1, 14, 1),	/* 14/1 => /14 */
55 	VID_PLL_DIV(0x7f80, 2, 15, 1),	/* 15/1 => /15 */
56 };
57 
58 #define to_meson_vid_pll_div(_hw) \
59 	container_of(_hw, struct meson_vid_pll_div, hw)
60 
61 static const struct vid_pll_div *_get_table_val(unsigned int shift_val,
62 						unsigned int shift_sel)
63 {
64 	int i;
65 
66 	for (i = 0 ; i < ARRAY_SIZE(vid_pll_div_table) ; ++i) {
67 		if (vid_pll_div_table[i].shift_val == shift_val &&
68 		    vid_pll_div_table[i].shift_sel == shift_sel)
69 			return &vid_pll_div_table[i];
70 	}
71 
72 	return NULL;
73 }
74 
75 static unsigned long meson_vid_pll_div_recalc_rate(struct clk_hw *hw,
76 						   unsigned long parent_rate)
77 {
78 	struct clk_regmap *clk = to_clk_regmap(hw);
79 	struct meson_vid_pll_div_data *pll_div = meson_vid_pll_div_data(clk);
80 	const struct vid_pll_div *div;
81 
82 	div = _get_table_val(meson_parm_read(clk->map, &pll_div->val),
83 			     meson_parm_read(clk->map, &pll_div->sel));
84 	if (!div || !div->divider) {
85 		pr_debug("%s: Invalid config value for vid_pll_div\n", __func__);
86 		return 0;
87 	}
88 
89 	return DIV_ROUND_UP_ULL(parent_rate * div->multiplier, div->divider);
90 }
91 
92 const struct clk_ops meson_vid_pll_div_ro_ops = {
93 	.recalc_rate	= meson_vid_pll_div_recalc_rate,
94 };
95 EXPORT_SYMBOL_GPL(meson_vid_pll_div_ro_ops);
96 
97 MODULE_DESCRIPTION("Amlogic video pll divider driver");
98 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
99 MODULE_LICENSE("GPL v2");
100