1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Marvell Armada 37xx SoC Time Base Generator clocks
4  *
5  * Marek Behun <marek.behun@nic.cz>
6  *
7  * Based on Linux driver by:
8  *   Gregory CLEMENT <gregory.clement@free-electrons.com>
9  */
10 
11 #include <common.h>
12 #include <clk-uclass.h>
13 #include <clk.h>
14 #include <dm.h>
15 #include <asm/io.h>
16 #include <asm/arch/cpu.h>
17 
18 #define NUM_TBG	    4
19 
20 #define TBG_CTRL0		0x4
21 #define TBG_CTRL1		0x8
22 #define TBG_CTRL7		0x20
23 #define TBG_CTRL8		0x30
24 
25 #define TBG_DIV_MASK		0x1FF
26 
27 #define TBG_A_REFDIV		0
28 #define TBG_B_REFDIV		16
29 
30 #define TBG_A_FBDIV		2
31 #define TBG_B_FBDIV		18
32 
33 #define TBG_A_VCODIV_SE		0
34 #define TBG_B_VCODIV_SE		16
35 
36 #define TBG_A_VCODIV_DIFF	1
37 #define TBG_B_VCODIV_DIFF	17
38 
39 struct tbg_def {
40 	const char *name;
41 	u32 refdiv_offset;
42 	u32 fbdiv_offset;
43 	u32 vcodiv_reg;
44 	u32 vcodiv_offset;
45 };
46 
47 static const struct tbg_def tbg[NUM_TBG] = {
48 	{"TBG-A-P", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL8, TBG_A_VCODIV_DIFF},
49 	{"TBG-B-P", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL8, TBG_B_VCODIV_DIFF},
50 	{"TBG-A-S", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL1, TBG_A_VCODIV_SE},
51 	{"TBG-B-S", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL1, TBG_B_VCODIV_SE},
52 };
53 
54 struct a37xx_tbgclk {
55 	ulong rates[NUM_TBG];
56 	unsigned int mult[NUM_TBG];
57 	unsigned int div[NUM_TBG];
58 };
59 
60 static unsigned int tbg_get_mult(void __iomem *reg, const struct tbg_def *ptbg)
61 {
62 	u32 val;
63 
64 	val = readl(reg + TBG_CTRL0);
65 
66 	return ((val >> ptbg->fbdiv_offset) & TBG_DIV_MASK) << 2;
67 }
68 
69 static unsigned int tbg_get_div(void __iomem *reg, const struct tbg_def *ptbg)
70 {
71 	u32 val;
72 	unsigned int div;
73 
74 	val = readl(reg + TBG_CTRL7);
75 
76 	div = (val >> ptbg->refdiv_offset) & TBG_DIV_MASK;
77 	if (div == 0)
78 		div = 1;
79 	val = readl(reg + ptbg->vcodiv_reg);
80 
81 	div *= 1 << ((val >>  ptbg->vcodiv_offset) & TBG_DIV_MASK);
82 
83 	return div;
84 }
85 
86 static ulong armada_37xx_tbg_clk_get_rate(struct clk *clk)
87 {
88 	struct a37xx_tbgclk *priv = dev_get_priv(clk->dev);
89 
90 	if (clk->id >= NUM_TBG)
91 		return -ENODEV;
92 
93 	return priv->rates[clk->id];
94 }
95 
96 #if defined(CONFIG_CMD_CLK) && defined(CONFIG_CLK_ARMADA_3720)
97 int armada_37xx_tbg_clk_dump(struct udevice *dev)
98 {
99 	struct a37xx_tbgclk *priv = dev_get_priv(dev);
100 	int i;
101 
102 	for (i = 0; i < NUM_TBG; ++i)
103 		printf("  %s at %lu Hz\n", tbg[i].name,
104 		       priv->rates[i]);
105 	printf("\n");
106 
107 	return 0;
108 }
109 #endif
110 
111 static int armada_37xx_tbg_clk_probe(struct udevice *dev)
112 {
113 	struct a37xx_tbgclk *priv = dev_get_priv(dev);
114 	void __iomem *reg;
115 	ulong xtal;
116 	int i;
117 
118 	reg = dev_read_addr_ptr(dev);
119 	if (!reg) {
120 		dev_err(dev, "no io address\n");
121 		return -ENODEV;
122 	}
123 
124 	xtal = (ulong)get_ref_clk() * 1000000;
125 
126 	for (i = 0; i < NUM_TBG; ++i) {
127 		unsigned int mult, div;
128 
129 		mult = tbg_get_mult(reg, &tbg[i]);
130 		div = tbg_get_div(reg, &tbg[i]);
131 
132 		priv->rates[i] = (xtal * mult) / div;
133 	}
134 
135 	return 0;
136 }
137 
138 static const struct clk_ops armada_37xx_tbg_clk_ops = {
139 	.get_rate = armada_37xx_tbg_clk_get_rate,
140 };
141 
142 static const struct udevice_id armada_37xx_tbg_clk_ids[] = {
143 	{ .compatible = "marvell,armada-3700-tbg-clock" },
144 	{}
145 };
146 
147 U_BOOT_DRIVER(armada_37xx_tbg_clk) = {
148 	.name		= "armada_37xx_tbg_clk",
149 	.id		= UCLASS_CLK,
150 	.of_match	= armada_37xx_tbg_clk_ids,
151 	.ops		= &armada_37xx_tbg_clk_ops,
152 	.priv_auto_alloc_size = sizeof(struct a37xx_tbgclk),
153 	.probe		= armada_37xx_tbg_clk_probe,
154 };
155