1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2015 Altera Corporation. All rights reserved
4  */
5 #include <linux/slab.h>
6 #include <linux/clk-provider.h>
7 #include <linux/io.h>
8 #include <linux/of.h>
9 #include <linux/of_address.h>
10 
11 #include "clk.h"
12 
13 /* Clock Manager offsets */
14 #define CLK_MGR_PLL_CLK_SRC_SHIFT	8
15 #define CLK_MGR_PLL_CLK_SRC_MASK	0x3
16 
17 /* Clock bypass bits */
18 #define SOCFPGA_PLL_BG_PWRDWN		0
19 #define SOCFPGA_PLL_PWR_DOWN		1
20 #define SOCFPGA_PLL_EXT_ENA		2
21 #define SOCFPGA_PLL_DIVF_MASK		0x00001FFF
22 #define SOCFPGA_PLL_DIVF_SHIFT	0
23 #define SOCFPGA_PLL_DIVQ_MASK		0x003F0000
24 #define SOCFPGA_PLL_DIVQ_SHIFT	16
25 #define SOCFGPA_MAX_PARENTS	5
26 
27 #define SOCFPGA_MAIN_PLL_CLK		"main_pll"
28 #define SOCFPGA_PERIP_PLL_CLK		"periph_pll"
29 
30 #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
31 
32 void __iomem *clk_mgr_a10_base_addr;
33 
34 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
35 					 unsigned long parent_rate)
36 {
37 	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
38 	unsigned long divf, divq, reg;
39 	unsigned long long vco_freq;
40 
41 	/* read VCO1 reg for numerator and denominator */
42 	reg = readl(socfpgaclk->hw.reg + 0x4);
43 	divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
44 	divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
45 	vco_freq = (unsigned long long)parent_rate * (divf + 1);
46 	do_div(vco_freq, (1 + divq));
47 	return (unsigned long)vco_freq;
48 }
49 
50 static u8 clk_pll_get_parent(struct clk_hw *hwclk)
51 {
52 	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
53 	u32 pll_src;
54 
55 	pll_src = readl(socfpgaclk->hw.reg);
56 
57 	return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) &
58 		CLK_MGR_PLL_CLK_SRC_MASK;
59 }
60 
61 static const struct clk_ops clk_pll_ops = {
62 	.recalc_rate = clk_pll_recalc_rate,
63 	.get_parent = clk_pll_get_parent,
64 };
65 
66 static struct clk * __init __socfpga_pll_init(struct device_node *node,
67 	const struct clk_ops *ops)
68 {
69 	u32 reg;
70 	struct clk *clk;
71 	struct socfpga_pll *pll_clk;
72 	const char *clk_name = node->name;
73 	const char *parent_name[SOCFGPA_MAX_PARENTS];
74 	struct clk_init_data init;
75 	struct device_node *clkmgr_np;
76 	int i = 0;
77 
78 	of_property_read_u32(node, "reg", &reg);
79 
80 	pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
81 	if (WARN_ON(!pll_clk))
82 		return NULL;
83 
84 	clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr");
85 	clk_mgr_a10_base_addr = of_iomap(clkmgr_np, 0);
86 	of_node_put(clkmgr_np);
87 	BUG_ON(!clk_mgr_a10_base_addr);
88 	pll_clk->hw.reg = clk_mgr_a10_base_addr + reg;
89 
90 	of_property_read_string(node, "clock-output-names", &clk_name);
91 
92 	init.name = clk_name;
93 	init.ops = ops;
94 	init.flags = 0;
95 
96 	while (i < SOCFGPA_MAX_PARENTS && (parent_name[i] =
97 			of_clk_get_parent_name(node, i)) != NULL)
98 		i++;
99 	init.num_parents = i;
100 	init.parent_names = parent_name;
101 	pll_clk->hw.hw.init = &init;
102 
103 	pll_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
104 
105 	clk = clk_register(NULL, &pll_clk->hw.hw);
106 	if (WARN_ON(IS_ERR(clk))) {
107 		kfree(pll_clk);
108 		return NULL;
109 	}
110 	of_clk_add_provider(node, of_clk_src_simple_get, clk);
111 	return clk;
112 }
113 
114 void __init socfpga_a10_pll_init(struct device_node *node)
115 {
116 	__socfpga_pll_init(node, &clk_pll_ops);
117 }
118