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
32void __iomem *clk_mgr_a10_base_addr;
33
34static 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(addr: 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
50static 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(addr: socfpgaclk->hw.reg);
56
57 return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) &
58 CLK_MGR_PLL_CLK_SRC_MASK;
59}
60
61static const struct clk_ops clk_pll_ops = {
62 .recalc_rate = clk_pll_recalc_rate,
63 .get_parent = clk_pll_get_parent,
64};
65
66static void __init __socfpga_pll_init(struct device_node *node,
67 const struct clk_ops *ops)
68{
69 u32 reg;
70 struct clk_hw *hw_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(np: node, propname: "reg", out_value: &reg);
80
81 pll_clk = kzalloc(size: sizeof(*pll_clk), GFP_KERNEL);
82 if (WARN_ON(!pll_clk))
83 return;
84
85 clkmgr_np = of_find_compatible_node(NULL, NULL, compat: "altr,clk-mgr");
86 clk_mgr_a10_base_addr = of_iomap(node: clkmgr_np, index: 0);
87 of_node_put(node: 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(np: node, propname: "clock-output-names", out_string: &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(np: node, index: 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 hw_clk = &pll_clk->hw.hw;
106
107 rc = clk_hw_register(NULL, hw: hw_clk);
108 if (rc) {
109 pr_err("Could not register clock:%s\n", clk_name);
110 goto err_clk_hw_register;
111 }
112
113 rc = of_clk_add_hw_provider(np: node, get: of_clk_hw_simple_get, data: hw_clk);
114 if (rc) {
115 pr_err("Could not register clock provider for node:%s\n",
116 clk_name);
117 goto err_of_clk_add_hw_provider;
118 }
119
120 return;
121
122err_of_clk_add_hw_provider:
123 clk_hw_unregister(hw: hw_clk);
124err_clk_hw_register:
125 kfree(objp: pll_clk);
126}
127
128void __init socfpga_a10_pll_init(struct device_node *node)
129{
130 __socfpga_pll_init(node, ops: &clk_pll_ops);
131}
132

source code of linux/drivers/clk/socfpga/clk-pll-a10.c