xref: /openbmc/linux/drivers/clk/socfpga/clk-gate.c (revision f71a261a)
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 
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 
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 
90 static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
91 	unsigned long parent_rate)
92 {
93 	struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
94 	u32 div = 1, val;
95 
96 	if (socfpgaclk->fixed_div)
97 		div = socfpgaclk->fixed_div;
98 	else if (socfpgaclk->div_reg) {
99 		val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
100 		val &= GENMASK(socfpgaclk->width - 1, 0);
101 		/* Check for GPIO_DB_CLK by its offset */
102 		if ((uintptr_t) socfpgaclk->div_reg & SOCFPGA_GPIO_DB_CLK_OFFSET)
103 			div = val + 1;
104 		else
105 			div = (1 << val);
106 	}
107 
108 	return parent_rate / div;
109 }
110 
111 static int socfpga_clk_prepare(struct clk_hw *hwclk)
112 {
113 	struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
114 	struct regmap *sys_mgr_base_addr;
115 	int i;
116 	u32 hs_timing;
117 	u32 clk_phase[2];
118 
119 	if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
120 		sys_mgr_base_addr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
121 		if (IS_ERR(sys_mgr_base_addr)) {
122 			pr_err("%s: failed to find altr,sys-mgr regmap!\n", __func__);
123 			return -EINVAL;
124 		}
125 
126 		for (i = 0; i < 2; i++) {
127 			switch (socfpgaclk->clk_phase[i]) {
128 			case 0:
129 				clk_phase[i] = 0;
130 				break;
131 			case 45:
132 				clk_phase[i] = 1;
133 				break;
134 			case 90:
135 				clk_phase[i] = 2;
136 				break;
137 			case 135:
138 				clk_phase[i] = 3;
139 				break;
140 			case 180:
141 				clk_phase[i] = 4;
142 				break;
143 			case 225:
144 				clk_phase[i] = 5;
145 				break;
146 			case 270:
147 				clk_phase[i] = 6;
148 				break;
149 			case 315:
150 				clk_phase[i] = 7;
151 				break;
152 			default:
153 				clk_phase[i] = 0;
154 				break;
155 			}
156 		}
157 		hs_timing = SYSMGR_SDMMC_CTRL_SET(clk_phase[0], clk_phase[1]);
158 		regmap_write(sys_mgr_base_addr, SYSMGR_SDMMCGRP_CTRL_OFFSET,
159 			hs_timing);
160 	}
161 	return 0;
162 }
163 
164 static struct clk_ops gateclk_ops = {
165 	.prepare = socfpga_clk_prepare,
166 	.recalc_rate = socfpga_clk_recalc_rate,
167 	.get_parent = socfpga_clk_get_parent,
168 	.set_parent = socfpga_clk_set_parent,
169 };
170 
171 void __init socfpga_gate_init(struct device_node *node)
172 {
173 	u32 clk_gate[2];
174 	u32 div_reg[3];
175 	u32 clk_phase[2];
176 	u32 fixed_div;
177 	struct clk_hw *hw_clk;
178 	struct socfpga_gate_clk *socfpga_clk;
179 	const char *clk_name = node->name;
180 	const char *parent_name[SOCFPGA_MAX_PARENTS];
181 	struct clk_init_data init;
182 	struct clk_ops *ops;
183 	int rc;
184 	int err;
185 
186 	socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
187 	if (WARN_ON(!socfpga_clk))
188 		return;
189 
190 	ops = kmemdup(&gateclk_ops, sizeof(gateclk_ops), GFP_KERNEL);
191 	if (WARN_ON(!ops))
192 		return;
193 
194 	rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
195 	if (rc)
196 		clk_gate[0] = 0;
197 
198 	if (clk_gate[0]) {
199 		socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
200 		socfpga_clk->hw.bit_idx = clk_gate[1];
201 
202 		ops->enable = clk_gate_ops.enable;
203 		ops->disable = clk_gate_ops.disable;
204 	}
205 
206 	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
207 	if (rc)
208 		socfpga_clk->fixed_div = 0;
209 	else
210 		socfpga_clk->fixed_div = fixed_div;
211 
212 	rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
213 	if (!rc) {
214 		socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
215 		socfpga_clk->shift = div_reg[1];
216 		socfpga_clk->width = div_reg[2];
217 	} else {
218 		socfpga_clk->div_reg = NULL;
219 	}
220 
221 	rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2);
222 	if (!rc) {
223 		socfpga_clk->clk_phase[0] = clk_phase[0];
224 		socfpga_clk->clk_phase[1] = clk_phase[1];
225 	}
226 
227 	of_property_read_string(node, "clock-output-names", &clk_name);
228 
229 	init.name = clk_name;
230 	init.ops = ops;
231 	init.flags = 0;
232 
233 	init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
234 	if (init.num_parents < 2) {
235 		ops->get_parent = NULL;
236 		ops->set_parent = NULL;
237 	}
238 
239 	init.parent_names = parent_name;
240 	socfpga_clk->hw.hw.init = &init;
241 
242 	hw_clk = &socfpga_clk->hw.hw;
243 
244 	err = clk_hw_register(NULL, hw_clk);
245 	if (err) {
246 		kfree(socfpga_clk);
247 		return;
248 	}
249 	rc = of_clk_add_provider(node, of_clk_src_simple_get, hw_clk);
250 	if (WARN_ON(rc))
251 		return;
252 }
253