1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2019 MediaTek Inc. All Rights Reserved.
4 *
5 * Author: Weijie Gao <weijie.gao@mediatek.com>
6 */
7
8 #include <common.h>
9 #include <clk-uclass.h>
10 #include <dm.h>
11 #include <dt-bindings/clock/mt7628-clk.h>
12 #include <linux/bitops.h>
13 #include <linux/io.h>
14
15 /* SYSCFG0 */
16 #define XTAL_40M_SEL BIT(6)
17
18 /* CLKCFG0 */
19 #define CLKCFG0_REG 0x0
20 #define PERI_CLK_FROM_XTAL_SEL BIT(4)
21 #define CPU_PLL_FROM_BBP BIT(1)
22 #define CPU_PLL_FROM_XTAL BIT(0)
23
24 /* CLKCFG1 */
25 #define CLKCFG1_REG 0x4
26
27 #define CLK_SRC_CPU -1
28 #define CLK_SRC_CPU_D2 -2
29 #define CLK_SRC_SYS -3
30 #define CLK_SRC_XTAL -4
31 #define CLK_SRC_PERI -5
32
33 struct mt7628_clk_priv {
34 void __iomem *base;
35 int cpu_clk;
36 int sys_clk;
37 int xtal_clk;
38 };
39
40 static const int mt7628_clks[] = {
41 [CLK_SYS] = CLK_SRC_SYS,
42 [CLK_CPU] = CLK_SRC_CPU,
43 [CLK_XTAL] = CLK_SRC_XTAL,
44 [CLK_PWM] = CLK_SRC_PERI,
45 [CLK_MIPS_CNT] = CLK_SRC_CPU_D2,
46 [CLK_UART2] = CLK_SRC_PERI,
47 [CLK_UART1] = CLK_SRC_PERI,
48 [CLK_UART0] = CLK_SRC_PERI,
49 [CLK_SPI] = CLK_SRC_SYS,
50 [CLK_I2C] = CLK_SRC_PERI,
51 };
52
mt7628_clk_get_rate(struct clk * clk)53 static ulong mt7628_clk_get_rate(struct clk *clk)
54 {
55 struct mt7628_clk_priv *priv = dev_get_priv(clk->dev);
56 u32 val;
57
58 if (clk->id >= ARRAY_SIZE(mt7628_clks))
59 return 0;
60
61 switch (mt7628_clks[clk->id]) {
62 case CLK_SRC_CPU:
63 return priv->cpu_clk;
64 case CLK_SRC_CPU_D2:
65 return priv->cpu_clk / 2;
66 case CLK_SRC_SYS:
67 return priv->sys_clk;
68 case CLK_SRC_XTAL:
69 return priv->xtal_clk;
70 case CLK_SRC_PERI:
71 val = readl(priv->base + CLKCFG0_REG);
72 if (val & PERI_CLK_FROM_XTAL_SEL)
73 return priv->xtal_clk;
74 else
75 return 40000000;
76 default:
77 return mt7628_clks[clk->id];
78 }
79 }
80
mt7628_clk_enable(struct clk * clk)81 static int mt7628_clk_enable(struct clk *clk)
82 {
83 struct mt7628_clk_priv *priv = dev_get_priv(clk->dev);
84
85 if (clk->id > 31)
86 return -1;
87
88 setbits_32(priv->base + CLKCFG1_REG, BIT(clk->id));
89
90 return 0;
91 }
92
mt7628_clk_disable(struct clk * clk)93 static int mt7628_clk_disable(struct clk *clk)
94 {
95 struct mt7628_clk_priv *priv = dev_get_priv(clk->dev);
96
97 if (clk->id > 31)
98 return -1;
99
100 clrbits_32(priv->base + CLKCFG1_REG, BIT(clk->id));
101
102 return 0;
103 }
104
105 const struct clk_ops mt7628_clk_ops = {
106 .enable = mt7628_clk_enable,
107 .disable = mt7628_clk_disable,
108 .get_rate = mt7628_clk_get_rate,
109 };
110
mt7628_clk_probe(struct udevice * dev)111 static int mt7628_clk_probe(struct udevice *dev)
112 {
113 struct mt7628_clk_priv *priv = dev_get_priv(dev);
114 void __iomem *syscfg_base;
115 u32 val;
116
117 priv->base = (void __iomem *)dev_remap_addr_index(dev, 0);
118 if (!priv->base)
119 return -EINVAL;
120
121 syscfg_base = (void __iomem *)dev_remap_addr_index(dev, 1);
122 if (!syscfg_base)
123 return -EINVAL;
124
125 val = readl(syscfg_base);
126 if (val & XTAL_40M_SEL)
127 priv->xtal_clk = 40000000;
128 else
129 priv->xtal_clk = 25000000;
130
131 val = readl(priv->base + CLKCFG0_REG);
132 if (val & CPU_PLL_FROM_BBP)
133 priv->cpu_clk = 480000000;
134 else if (val & CPU_PLL_FROM_XTAL)
135 priv->cpu_clk = priv->xtal_clk;
136 else if (priv->xtal_clk == 40000000)
137 priv->cpu_clk = 580000000; /* (xtal_freq / 2) * 29 */
138 else
139 priv->cpu_clk = 575000000; /* xtal_freq * 23 */
140
141 priv->sys_clk = priv->cpu_clk / 3;
142
143 return 0;
144 }
145
146 static const struct udevice_id mt7628_clk_ids[] = {
147 { .compatible = "mediatek,mt7628-clk" },
148 { }
149 };
150
151 U_BOOT_DRIVER(mt7628_clk) = {
152 .name = "mt7628-clk",
153 .id = UCLASS_CLK,
154 .of_match = mt7628_clk_ids,
155 .probe = mt7628_clk_probe,
156 .priv_auto = sizeof(struct mt7628_clk_priv),
157 .ops = &mt7628_clk_ops,
158 };
159