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/mfd/syscon.h>
9#include <linux/of.h>
10#include <linux/regmap.h>
11
12#include "clk.h"
13
14#define streq(a, b) (strcmp((a), (b)) == 0)
15
16#define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
17
18/* SDMMC Group for System Manager defines */
19#define SYSMGR_SDMMCGRP_CTRL_OFFSET 0x28
20
21static unsigned long socfpga_gate_clk_recalc_rate(struct clk_hw *hwclk,
22 unsigned long parent_rate)
23{
24 struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
25 u32 div = 1, val;
26
27 if (socfpgaclk->fixed_div)
28 div = socfpgaclk->fixed_div;
29 else if (socfpgaclk->div_reg) {
30 val = readl(addr: socfpgaclk->div_reg) >> socfpgaclk->shift;
31 val &= GENMASK(socfpgaclk->width - 1, 0);
32 div = (1 << val);
33 }
34
35 return parent_rate / div;
36}
37
38static struct clk_ops gateclk_ops = {
39 .recalc_rate = socfpga_gate_clk_recalc_rate,
40};
41
42static void __init __socfpga_gate_init(struct device_node *node,
43 const struct clk_ops *ops)
44{
45 u32 clk_gate[2];
46 u32 div_reg[3];
47 u32 fixed_div;
48 struct clk_hw *hw_clk;
49 struct socfpga_gate_clk *socfpga_clk;
50 const char *clk_name = node->name;
51 const char *parent_name[SOCFPGA_MAX_PARENTS];
52 struct clk_init_data init;
53 int rc;
54
55 socfpga_clk = kzalloc(size: sizeof(*socfpga_clk), GFP_KERNEL);
56 if (WARN_ON(!socfpga_clk))
57 return;
58
59 rc = of_property_read_u32_array(np: node, propname: "clk-gate", out_values: clk_gate, sz: 2);
60 if (rc)
61 clk_gate[0] = 0;
62
63 if (clk_gate[0]) {
64 socfpga_clk->hw.reg = clk_mgr_a10_base_addr + clk_gate[0];
65 socfpga_clk->hw.bit_idx = clk_gate[1];
66
67 gateclk_ops.enable = clk_gate_ops.enable;
68 gateclk_ops.disable = clk_gate_ops.disable;
69 }
70
71 rc = of_property_read_u32(np: node, propname: "fixed-divider", out_value: &fixed_div);
72 if (rc)
73 socfpga_clk->fixed_div = 0;
74 else
75 socfpga_clk->fixed_div = fixed_div;
76
77 rc = of_property_read_u32_array(np: node, propname: "div-reg", out_values: div_reg, sz: 3);
78 if (!rc) {
79 socfpga_clk->div_reg = clk_mgr_a10_base_addr + div_reg[0];
80 socfpga_clk->shift = div_reg[1];
81 socfpga_clk->width = div_reg[2];
82 } else {
83 socfpga_clk->div_reg = NULL;
84 }
85
86 of_property_read_string(np: node, propname: "clock-output-names", out_string: &clk_name);
87
88 init.name = clk_name;
89 init.ops = ops;
90 init.flags = 0;
91
92 init.num_parents = of_clk_parent_fill(np: node, parents: parent_name, SOCFPGA_MAX_PARENTS);
93 init.parent_names = parent_name;
94 socfpga_clk->hw.hw.init = &init;
95 hw_clk = &socfpga_clk->hw.hw;
96
97 rc = clk_hw_register(NULL, hw: hw_clk);
98 if (rc) {
99 pr_err("Could not register clock:%s\n", clk_name);
100 goto err_clk_hw_register;
101 }
102
103 rc = of_clk_add_hw_provider(np: node, get: of_clk_hw_simple_get, data: hw_clk);
104 if (rc) {
105 pr_err("Could not register clock provider for node:%s\n",
106 clk_name);
107 goto err_of_clk_add_hw_provider;
108 }
109
110 return;
111
112err_of_clk_add_hw_provider:
113 clk_hw_unregister(hw: hw_clk);
114err_clk_hw_register:
115 kfree(objp: socfpga_clk);
116}
117
118void __init socfpga_a10_gate_init(struct device_node *node)
119{
120 __socfpga_gate_init(node, ops: &gateclk_ops);
121}
122

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