1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2011-2012 Calxeda, Inc.
4 * Copyright (C) 2012-2013 Altera Corporation <www.altera.com>
5 *
6 * Based from clk-highbank.c
7 */
8 #include <linux/slab.h>
9 #include <linux/clk-provider.h>
10 #include <linux/io.h>
11 #include <linux/mfd/syscon.h>
12 #include <linux/of.h>
13 #include <linux/regmap.h>
14
15 #include "clk.h"
16
17 #define SOCFPGA_L4_MP_CLK "l4_mp_clk"
18 #define SOCFPGA_L4_SP_CLK "l4_sp_clk"
19 #define SOCFPGA_NAND_CLK "nand_clk"
20 #define SOCFPGA_NAND_X_CLK "nand_x_clk"
21 #define SOCFPGA_MMC_CLK "sdmmc_clk"
22 #define SOCFPGA_GPIO_DB_CLK_OFFSET 0xA8
23
24 #define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
25
26 /* SDMMC Group for System Manager defines */
27 #define SYSMGR_SDMMCGRP_CTRL_OFFSET 0x108
28
socfpga_clk_get_parent(struct clk_hw * hwclk)29 static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
30 {
31 u32 l4_src;
32 u32 perpll_src;
33 const char *name = clk_hw_get_name(hwclk);
34
35 if (streq(name, SOCFPGA_L4_MP_CLK)) {
36 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
37 return l4_src & 0x1;
38 }
39 if (streq(name, SOCFPGA_L4_SP_CLK)) {
40 l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
41 return !!(l4_src & 2);
42 }
43
44 perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
45 if (streq(name, SOCFPGA_MMC_CLK))
46 return perpll_src & 0x3;
47 if (streq(name, SOCFPGA_NAND_CLK) ||
48 streq(name, SOCFPGA_NAND_X_CLK))
49 return (perpll_src >> 2) & 3;
50
51 /* QSPI clock */
52 return (perpll_src >> 4) & 3;
53
54 }
55
socfpga_clk_set_parent(struct clk_hw * hwclk,u8 parent)56 static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent)
57 {
58 u32 src_reg;
59 const char *name = clk_hw_get_name(hwclk);
60
61 if (streq(name, SOCFPGA_L4_MP_CLK)) {
62 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
63 src_reg &= ~0x1;
64 src_reg |= parent;
65 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
66 } else if (streq(name, SOCFPGA_L4_SP_CLK)) {
67 src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
68 src_reg &= ~0x2;
69 src_reg |= (parent << 1);
70 writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
71 } else {
72 src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
73 if (streq(name, SOCFPGA_MMC_CLK)) {
74 src_reg &= ~0x3;
75 src_reg |= parent;
76 } else if (streq(name, SOCFPGA_NAND_CLK) ||
77 streq(name, SOCFPGA_NAND_X_CLK)) {
78 src_reg &= ~0xC;
79 src_reg |= (parent << 2);
80 } else {/* QSPI clock */
81 src_reg &= ~0x30;
82 src_reg |= (parent << 4);
83 }
84 writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
85 }
86
87 return 0;
88 }
89
socfpga_clk_get_div(struct socfpga_gate_clk * socfpgaclk)90 static u32 socfpga_clk_get_div(struct socfpga_gate_clk *socfpgaclk)
91 {
92 u32 div = 1, val;
93
94 if (socfpgaclk->fixed_div)
95 div = socfpgaclk->fixed_div;
96 else if (socfpgaclk->div_reg) {
97 val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
98 val &= GENMASK(socfpgaclk->width - 1, 0);
99 /* Check for GPIO_DB_CLK by its offset */
100 if ((uintptr_t) socfpgaclk->div_reg & SOCFPGA_GPIO_DB_CLK_OFFSET)
101 div = val + 1;
102 else
103 div = (1 << val);
104 }
105
106 return div;
107 }
108
socfpga_clk_recalc_rate(struct clk_hw * hwclk,unsigned long parent_rate)109 static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
110 unsigned long parent_rate)
111 {
112 struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
113 u32 div = socfpga_clk_get_div(socfpgaclk);
114
115 return parent_rate / div;
116 }
117
118
socfpga_clk_determine_rate(struct clk_hw * hwclk,struct clk_rate_request * req)119 static int socfpga_clk_determine_rate(struct clk_hw *hwclk,
120 struct clk_rate_request *req)
121 {
122 struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
123 u32 div = socfpga_clk_get_div(socfpgaclk);
124
125 req->rate = req->best_parent_rate / div;
126
127 return 0;
128 }
129
130 static struct clk_ops gateclk_ops = {
131 .recalc_rate = socfpga_clk_recalc_rate,
132 .determine_rate = socfpga_clk_determine_rate,
133 .get_parent = socfpga_clk_get_parent,
134 .set_parent = socfpga_clk_set_parent,
135 };
136
socfpga_gate_init(struct device_node * node)137 void __init socfpga_gate_init(struct device_node *node)
138 {
139 u32 clk_gate[2];
140 u32 div_reg[3];
141 u32 fixed_div;
142 struct clk_hw *hw_clk;
143 struct socfpga_gate_clk *socfpga_clk;
144 const char *clk_name = node->name;
145 const char *parent_name[SOCFPGA_MAX_PARENTS];
146 struct clk_init_data init;
147 struct clk_ops *ops;
148 int rc;
149
150 socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
151 if (WARN_ON(!socfpga_clk))
152 return;
153
154 ops = kmemdup(&gateclk_ops, sizeof(gateclk_ops), GFP_KERNEL);
155 if (WARN_ON(!ops))
156 goto err_kmemdup;
157
158 rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
159 if (rc)
160 clk_gate[0] = 0;
161
162 if (clk_gate[0]) {
163 socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
164 socfpga_clk->hw.bit_idx = clk_gate[1];
165
166 ops->enable = clk_gate_ops.enable;
167 ops->disable = clk_gate_ops.disable;
168 }
169
170 rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
171 if (rc)
172 socfpga_clk->fixed_div = 0;
173 else
174 socfpga_clk->fixed_div = fixed_div;
175
176 rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
177 if (!rc) {
178 socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
179 socfpga_clk->shift = div_reg[1];
180 socfpga_clk->width = div_reg[2];
181 } else {
182 socfpga_clk->div_reg = NULL;
183 }
184
185 of_property_read_string(node, "clock-output-names", &clk_name);
186
187 init.name = clk_name;
188 init.ops = ops;
189 init.flags = 0;
190
191 init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
192 if (init.num_parents < 2) {
193 ops->get_parent = NULL;
194 ops->set_parent = NULL;
195 }
196
197 init.parent_names = parent_name;
198 socfpga_clk->hw.hw.init = &init;
199
200 hw_clk = &socfpga_clk->hw.hw;
201
202 rc = clk_hw_register(NULL, hw_clk);
203 if (rc) {
204 pr_err("Could not register clock:%s\n", clk_name);
205 goto err_clk_hw_register;
206 }
207
208 rc = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw_clk);
209 if (rc) {
210 pr_err("Could not register clock provider for node:%s\n",
211 clk_name);
212 goto err_of_clk_add_hw_provider;
213 }
214
215 return;
216
217 err_of_clk_add_hw_provider:
218 clk_hw_unregister(hw_clk);
219 err_clk_hw_register:
220 kfree(ops);
221 err_kmemdup:
222 kfree(socfpga_clk);
223 }
224