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
10 #include "clk.h"
11
12 #define CLK_MGR_FREE_SHIFT 16
13 #define CLK_MGR_FREE_MASK 0x7
14
15 #define SOCFPGA_MPU_FREE_CLK "mpu_free_clk"
16 #define SOCFPGA_NOC_FREE_CLK "noc_free_clk"
17 #define SOCFPGA_SDMMC_FREE_CLK "sdmmc_free_clk"
18 #define to_socfpga_periph_clk(p) container_of(p, struct socfpga_periph_clk, hw.hw)
19
clk_periclk_recalc_rate(struct clk_hw * hwclk,unsigned long parent_rate)20 static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk,
21 unsigned long parent_rate)
22 {
23 struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk);
24 u32 div;
25
26 if (socfpgaclk->fixed_div) {
27 div = socfpgaclk->fixed_div;
28 } else if (socfpgaclk->div_reg) {
29 div = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
30 div &= GENMASK(socfpgaclk->width - 1, 0);
31 div += 1;
32 } else {
33 div = ((readl(socfpgaclk->hw.reg) & 0x7ff) + 1);
34 }
35
36 return parent_rate / div;
37 }
38
clk_periclk_get_parent(struct clk_hw * hwclk)39 static u8 clk_periclk_get_parent(struct clk_hw *hwclk)
40 {
41 struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk);
42 u32 clk_src;
43 const char *name = clk_hw_get_name(hwclk);
44
45 clk_src = readl(socfpgaclk->hw.reg);
46 if (streq(name, SOCFPGA_MPU_FREE_CLK) ||
47 streq(name, SOCFPGA_NOC_FREE_CLK) ||
48 streq(name, SOCFPGA_SDMMC_FREE_CLK))
49 return (clk_src >> CLK_MGR_FREE_SHIFT) &
50 CLK_MGR_FREE_MASK;
51 else
52 return 0;
53 }
54
55 static const struct clk_ops periclk_ops = {
56 .recalc_rate = clk_periclk_recalc_rate,
57 .get_parent = clk_periclk_get_parent,
58 };
59
__socfpga_periph_init(struct device_node * node,const struct clk_ops * ops)60 static __init void __socfpga_periph_init(struct device_node *node,
61 const struct clk_ops *ops)
62 {
63 u32 reg;
64 struct clk_hw *hw_clk;
65 struct socfpga_periph_clk *periph_clk;
66 const char *clk_name = node->name;
67 const char *parent_name[SOCFPGA_MAX_PARENTS];
68 struct clk_init_data init;
69 int rc;
70 u32 fixed_div;
71 u32 div_reg[3];
72
73 of_property_read_u32(node, "reg", ®);
74
75 periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL);
76 if (WARN_ON(!periph_clk))
77 return;
78
79 periph_clk->hw.reg = clk_mgr_a10_base_addr + reg;
80
81 rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
82 if (!rc) {
83 periph_clk->div_reg = clk_mgr_a10_base_addr + div_reg[0];
84 periph_clk->shift = div_reg[1];
85 periph_clk->width = div_reg[2];
86 } else {
87 periph_clk->div_reg = NULL;
88 }
89
90 rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
91 if (rc)
92 periph_clk->fixed_div = 0;
93 else
94 periph_clk->fixed_div = fixed_div;
95
96 of_property_read_string(node, "clock-output-names", &clk_name);
97
98 init.name = clk_name;
99 init.ops = ops;
100 init.flags = 0;
101
102 init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
103 init.parent_names = parent_name;
104
105 periph_clk->hw.hw.init = &init;
106
107 hw_clk = &periph_clk->hw.hw;
108
109 if (clk_hw_register(NULL, hw_clk)) {
110 kfree(periph_clk);
111 return;
112 }
113 rc = of_clk_add_provider(node, of_clk_src_simple_get, hw_clk);
114 if (rc < 0) {
115 pr_err("Could not register clock provider for node:%s\n",
116 clk_name);
117 goto err_clk;
118 }
119
120 return;
121
122 err_clk:
123 clk_hw_unregister(hw_clk);
124 }
125
socfpga_a10_periph_init(struct device_node * node)126 void __init socfpga_a10_periph_init(struct device_node *node)
127 {
128 __socfpga_periph_init(node, &periclk_ops);
129 }
130