xref: /openbmc/linux/drivers/clk/renesas/clk-sh73a0.c (revision b9b77222)
1 /*
2  * sh73a0 Core CPG Clocks
3  *
4  * Copyright (C) 2014  Ulrich Hecht
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; version 2 of the License.
9  */
10 
11 #include <linux/clk-provider.h>
12 #include <linux/clk/renesas.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/slab.h>
18 #include <linux/spinlock.h>
19 
20 struct sh73a0_cpg {
21 	struct clk_onecell_data data;
22 	spinlock_t lock;
23 	void __iomem *reg;
24 };
25 
26 #define CPG_FRQCRA	0x00
27 #define CPG_FRQCRB	0x04
28 #define CPG_SD0CKCR	0x74
29 #define CPG_SD1CKCR	0x78
30 #define CPG_SD2CKCR	0x7c
31 #define CPG_PLLECR	0xd0
32 #define CPG_PLL0CR	0xd8
33 #define CPG_PLL1CR	0x28
34 #define CPG_PLL2CR	0x2c
35 #define CPG_PLL3CR	0xdc
36 #define CPG_CKSCR	0xc0
37 #define CPG_DSI0PHYCR	0x6c
38 #define CPG_DSI1PHYCR	0x70
39 
40 #define CLK_ENABLE_ON_INIT BIT(0)
41 
42 struct div4_clk {
43 	const char *name;
44 	const char *parent;
45 	unsigned int reg;
46 	unsigned int shift;
47 };
48 
49 static const struct div4_clk div4_clks[] = {
50 	{ "zg", "pll0", CPG_FRQCRA, 16 },
51 	{ "m3", "pll1", CPG_FRQCRA, 12 },
52 	{ "b",  "pll1", CPG_FRQCRA,  8 },
53 	{ "m1", "pll1", CPG_FRQCRA,  4 },
54 	{ "m2", "pll1", CPG_FRQCRA,  0 },
55 	{ "zx", "pll1", CPG_FRQCRB, 12 },
56 	{ "hp", "pll1", CPG_FRQCRB,  4 },
57 	{ NULL, NULL, 0, 0 },
58 };
59 
60 static const struct clk_div_table div4_div_table[] = {
61 	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
62 	{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
63 	{ 12, 7 }, { 0, 0 }
64 };
65 
66 static const struct clk_div_table z_div_table[] = {
67 	/* ZSEL == 0 */
68 	{ 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 }, { 4, 1 }, { 5, 1 },
69 	{ 6, 1 }, { 7, 1 }, { 8, 1 }, { 9, 1 }, { 10, 1 }, { 11, 1 },
70 	{ 12, 1 }, { 13, 1 }, { 14, 1 }, { 15, 1 },
71 	/* ZSEL == 1 */
72 	{ 16, 2 }, { 17, 3 }, { 18, 4 }, { 19, 6 }, { 20, 8 }, { 21, 12 },
73 	{ 22, 16 }, { 24, 24 }, { 27, 48 }, { 0, 0 }
74 };
75 
76 static struct clk * __init
77 sh73a0_cpg_register_clock(struct device_node *np, struct sh73a0_cpg *cpg,
78 			     const char *name)
79 {
80 	const struct clk_div_table *table = NULL;
81 	unsigned int shift, reg, width;
82 	const char *parent_name = NULL;
83 	unsigned int mult = 1;
84 	unsigned int div = 1;
85 
86 	if (!strcmp(name, "main")) {
87 		/* extal1, extal1_div2, extal2, extal2_div2 */
88 		u32 parent_idx = (readl(cpg->reg + CPG_CKSCR) >> 28) & 3;
89 
90 		parent_name = of_clk_get_parent_name(np, parent_idx >> 1);
91 		div = (parent_idx & 1) + 1;
92 	} else if (!strncmp(name, "pll", 3)) {
93 		void __iomem *enable_reg = cpg->reg;
94 		u32 enable_bit = name[3] - '0';
95 
96 		parent_name = "main";
97 		switch (enable_bit) {
98 		case 0:
99 			enable_reg += CPG_PLL0CR;
100 			break;
101 		case 1:
102 			enable_reg += CPG_PLL1CR;
103 			break;
104 		case 2:
105 			enable_reg += CPG_PLL2CR;
106 			break;
107 		case 3:
108 			enable_reg += CPG_PLL3CR;
109 			break;
110 		default:
111 			return ERR_PTR(-EINVAL);
112 		}
113 		if (readl(cpg->reg + CPG_PLLECR) & BIT(enable_bit)) {
114 			mult = ((readl(enable_reg) >> 24) & 0x3f) + 1;
115 			/* handle CFG bit for PLL1 and PLL2 */
116 			if (enable_bit == 1 || enable_bit == 2)
117 				if (readl(enable_reg) & BIT(20))
118 					mult *= 2;
119 		}
120 	} else if (!strcmp(name, "dsi0phy") || !strcmp(name, "dsi1phy")) {
121 		u32 phy_no = name[3] - '0';
122 		void __iomem *dsi_reg = cpg->reg +
123 			(phy_no ? CPG_DSI1PHYCR : CPG_DSI0PHYCR);
124 
125 		parent_name = phy_no ? "dsi1pck" : "dsi0pck";
126 		mult = __raw_readl(dsi_reg);
127 		if (!(mult & 0x8000))
128 			mult = 1;
129 		else
130 			mult = (mult & 0x3f) + 1;
131 	} else if (!strcmp(name, "z")) {
132 		parent_name = "pll0";
133 		table = z_div_table;
134 		reg = CPG_FRQCRB;
135 		shift = 24;
136 		width = 5;
137 	} else {
138 		const struct div4_clk *c;
139 
140 		for (c = div4_clks; c->name; c++) {
141 			if (!strcmp(name, c->name)) {
142 				parent_name = c->parent;
143 				table = div4_div_table;
144 				reg = c->reg;
145 				shift = c->shift;
146 				width = 4;
147 				break;
148 			}
149 		}
150 		if (!c->name)
151 			return ERR_PTR(-EINVAL);
152 	}
153 
154 	if (!table) {
155 		return clk_register_fixed_factor(NULL, name, parent_name, 0,
156 						 mult, div);
157 	} else {
158 		return clk_register_divider_table(NULL, name, parent_name, 0,
159 						  cpg->reg + reg, shift, width, 0,
160 						  table, &cpg->lock);
161 	}
162 }
163 
164 static void __init sh73a0_cpg_clocks_init(struct device_node *np)
165 {
166 	struct sh73a0_cpg *cpg;
167 	struct clk **clks;
168 	unsigned int i;
169 	int num_clks;
170 
171 	num_clks = of_property_count_strings(np, "clock-output-names");
172 	if (num_clks < 0) {
173 		pr_err("%s: failed to count clocks\n", __func__);
174 		return;
175 	}
176 
177 	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
178 	clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
179 	if (cpg == NULL || clks == NULL) {
180 		/* We're leaking memory on purpose, there's no point in cleaning
181 		 * up as the system won't boot anyway.
182 		 */
183 		return;
184 	}
185 
186 	spin_lock_init(&cpg->lock);
187 
188 	cpg->data.clks = clks;
189 	cpg->data.clk_num = num_clks;
190 
191 	cpg->reg = of_iomap(np, 0);
192 	if (WARN_ON(cpg->reg == NULL))
193 		return;
194 
195 	/* Set SDHI clocks to a known state */
196 	writel(0x108, cpg->reg + CPG_SD0CKCR);
197 	writel(0x108, cpg->reg + CPG_SD1CKCR);
198 	writel(0x108, cpg->reg + CPG_SD2CKCR);
199 
200 	for (i = 0; i < num_clks; ++i) {
201 		const char *name;
202 		struct clk *clk;
203 
204 		of_property_read_string_index(np, "clock-output-names", i,
205 					      &name);
206 
207 		clk = sh73a0_cpg_register_clock(np, cpg, name);
208 		if (IS_ERR(clk))
209 			pr_err("%s: failed to register %s %s clock (%ld)\n",
210 			       __func__, np->name, name, PTR_ERR(clk));
211 		else
212 			cpg->data.clks[i] = clk;
213 	}
214 
215 	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
216 }
217 CLK_OF_DECLARE(sh73a0_cpg_clks, "renesas,sh73a0-cpg-clocks",
218 	       sh73a0_cpg_clocks_init);
219