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
clk_pll_recalc_rate(struct clk_hw * hwclk,unsigned long parent_rate)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
clk_pll_get_parent(struct clk_hw * hwclk)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
__socfpga_pll_init(struct device_node * node,const struct clk_ops * ops)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 rc;
77 int i = 0;
78
79 of_property_read_u32(node, "reg", ®);
80
81 pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
82 if (WARN_ON(!pll_clk))
83 return NULL;
84
85 clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr");
86 clk_mgr_a10_base_addr = of_iomap(clkmgr_np, 0);
87 of_node_put(clkmgr_np);
88 BUG_ON(!clk_mgr_a10_base_addr);
89 pll_clk->hw.reg = clk_mgr_a10_base_addr + reg;
90
91 of_property_read_string(node, "clock-output-names", &clk_name);
92
93 init.name = clk_name;
94 init.ops = ops;
95 init.flags = 0;
96
97 while (i < SOCFGPA_MAX_PARENTS && (parent_name[i] =
98 of_clk_get_parent_name(node, i)) != NULL)
99 i++;
100 init.num_parents = i;
101 init.parent_names = parent_name;
102 pll_clk->hw.hw.init = &init;
103
104 pll_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
105
106 clk = clk_register(NULL, &pll_clk->hw.hw);
107 if (WARN_ON(IS_ERR(clk))) {
108 kfree(pll_clk);
109 return NULL;
110 }
111 rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
112 return clk;
113 }
114
socfpga_a10_pll_init(struct device_node * node)115 void __init socfpga_a10_pll_init(struct device_node *node)
116 {
117 __socfpga_pll_init(node, &clk_pll_ops);
118 }
119