xref: /openbmc/linux/drivers/clk/renesas/clk-sh73a0.c (revision bbb774d9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * sh73a0 Core CPG Clocks
4  *
5  * Copyright (C) 2014  Ulrich Hecht
6  */
7 
8 #include <linux/clk-provider.h>
9 #include <linux/clk/renesas.h>
10 #include <linux/init.h>
11 #include <linux/io.h>
12 #include <linux/kernel.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/slab.h>
16 #include <linux/spinlock.h>
17 
18 struct sh73a0_cpg {
19 	struct clk_onecell_data data;
20 	spinlock_t lock;
21 };
22 
23 #define CPG_FRQCRA	0x00
24 #define CPG_FRQCRB	0x04
25 #define CPG_SD0CKCR	0x74
26 #define CPG_SD1CKCR	0x78
27 #define CPG_SD2CKCR	0x7c
28 #define CPG_PLLECR	0xd0
29 #define CPG_PLL0CR	0xd8
30 #define CPG_PLL1CR	0x28
31 #define CPG_PLL2CR	0x2c
32 #define CPG_PLL3CR	0xdc
33 #define CPG_CKSCR	0xc0
34 #define CPG_DSI0PHYCR	0x6c
35 #define CPG_DSI1PHYCR	0x70
36 
37 #define CLK_ENABLE_ON_INIT BIT(0)
38 
39 struct div4_clk {
40 	const char *name;
41 	const char *parent;
42 	unsigned int reg;
43 	unsigned int shift;
44 };
45 
46 static const struct div4_clk div4_clks[] = {
47 	{ "zg", "pll0", CPG_FRQCRA, 16 },
48 	{ "m3", "pll1", CPG_FRQCRA, 12 },
49 	{ "b",  "pll1", CPG_FRQCRA,  8 },
50 	{ "m1", "pll1", CPG_FRQCRA,  4 },
51 	{ "m2", "pll1", CPG_FRQCRA,  0 },
52 	{ "zx", "pll1", CPG_FRQCRB, 12 },
53 	{ "hp", "pll1", CPG_FRQCRB,  4 },
54 	{ NULL, NULL, 0, 0 },
55 };
56 
57 static const struct clk_div_table div4_div_table[] = {
58 	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
59 	{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
60 	{ 12, 7 }, { 0, 0 }
61 };
62 
63 static const struct clk_div_table z_div_table[] = {
64 	/* ZSEL == 0 */
65 	{ 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 }, { 4, 1 }, { 5, 1 },
66 	{ 6, 1 }, { 7, 1 }, { 8, 1 }, { 9, 1 }, { 10, 1 }, { 11, 1 },
67 	{ 12, 1 }, { 13, 1 }, { 14, 1 }, { 15, 1 },
68 	/* ZSEL == 1 */
69 	{ 16, 2 }, { 17, 3 }, { 18, 4 }, { 19, 6 }, { 20, 8 }, { 21, 12 },
70 	{ 22, 16 }, { 24, 24 }, { 27, 48 }, { 0, 0 }
71 };
72 
73 static struct clk * __init
74 sh73a0_cpg_register_clock(struct device_node *np, struct sh73a0_cpg *cpg,
75 			  void __iomem *base, const char *name)
76 {
77 	const struct clk_div_table *table = NULL;
78 	unsigned int shift, reg, width;
79 	const char *parent_name = NULL;
80 	unsigned int mult = 1;
81 	unsigned int div = 1;
82 
83 	if (!strcmp(name, "main")) {
84 		/* extal1, extal1_div2, extal2, extal2_div2 */
85 		u32 parent_idx = (readl(base + CPG_CKSCR) >> 28) & 3;
86 
87 		parent_name = of_clk_get_parent_name(np, parent_idx >> 1);
88 		div = (parent_idx & 1) + 1;
89 	} else if (!strncmp(name, "pll", 3)) {
90 		void __iomem *enable_reg = base;
91 		u32 enable_bit = name[3] - '0';
92 
93 		parent_name = "main";
94 		switch (enable_bit) {
95 		case 0:
96 			enable_reg += CPG_PLL0CR;
97 			break;
98 		case 1:
99 			enable_reg += CPG_PLL1CR;
100 			break;
101 		case 2:
102 			enable_reg += CPG_PLL2CR;
103 			break;
104 		case 3:
105 			enable_reg += CPG_PLL3CR;
106 			break;
107 		default:
108 			return ERR_PTR(-EINVAL);
109 		}
110 		if (readl(base + CPG_PLLECR) & BIT(enable_bit)) {
111 			mult = ((readl(enable_reg) >> 24) & 0x3f) + 1;
112 			/* handle CFG bit for PLL1 and PLL2 */
113 			if (enable_bit == 1 || enable_bit == 2)
114 				if (readl(enable_reg) & BIT(20))
115 					mult *= 2;
116 		}
117 	} else if (!strcmp(name, "dsi0phy") || !strcmp(name, "dsi1phy")) {
118 		u32 phy_no = name[3] - '0';
119 		void __iomem *dsi_reg = base +
120 			(phy_no ? CPG_DSI1PHYCR : CPG_DSI0PHYCR);
121 
122 		parent_name = phy_no ? "dsi1pck" : "dsi0pck";
123 		mult = readl(dsi_reg);
124 		if (!(mult & 0x8000))
125 			mult = 1;
126 		else
127 			mult = (mult & 0x3f) + 1;
128 	} else if (!strcmp(name, "z")) {
129 		parent_name = "pll0";
130 		table = z_div_table;
131 		reg = CPG_FRQCRB;
132 		shift = 24;
133 		width = 5;
134 	} else {
135 		const struct div4_clk *c;
136 
137 		for (c = div4_clks; c->name; c++) {
138 			if (!strcmp(name, c->name)) {
139 				parent_name = c->parent;
140 				table = div4_div_table;
141 				reg = c->reg;
142 				shift = c->shift;
143 				width = 4;
144 				break;
145 			}
146 		}
147 		if (!c->name)
148 			return ERR_PTR(-EINVAL);
149 	}
150 
151 	if (!table) {
152 		return clk_register_fixed_factor(NULL, name, parent_name, 0,
153 						 mult, div);
154 	} else {
155 		return clk_register_divider_table(NULL, name, parent_name, 0,
156 						  base + reg, shift, width, 0,
157 						  table, &cpg->lock);
158 	}
159 }
160 
161 static void __init sh73a0_cpg_clocks_init(struct device_node *np)
162 {
163 	struct sh73a0_cpg *cpg;
164 	void __iomem *base;
165 	struct clk **clks;
166 	unsigned int i;
167 	int num_clks;
168 
169 	num_clks = of_property_count_strings(np, "clock-output-names");
170 	if (num_clks < 0) {
171 		pr_err("%s: failed to count clocks\n", __func__);
172 		return;
173 	}
174 
175 	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
176 	clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
177 	if (cpg == NULL || clks == NULL) {
178 		/* We're leaking memory on purpose, there's no point in cleaning
179 		 * up as the system won't boot anyway.
180 		 */
181 		return;
182 	}
183 
184 	spin_lock_init(&cpg->lock);
185 
186 	cpg->data.clks = clks;
187 	cpg->data.clk_num = num_clks;
188 
189 	base = of_iomap(np, 0);
190 	if (WARN_ON(base == NULL))
191 		return;
192 
193 	/* Set SDHI clocks to a known state */
194 	writel(0x108, base + CPG_SD0CKCR);
195 	writel(0x108, base + CPG_SD1CKCR);
196 	writel(0x108, base + CPG_SD2CKCR);
197 
198 	for (i = 0; i < num_clks; ++i) {
199 		const char *name;
200 		struct clk *clk;
201 
202 		of_property_read_string_index(np, "clock-output-names", i,
203 					      &name);
204 
205 		clk = sh73a0_cpg_register_clock(np, cpg, base, name);
206 		if (IS_ERR(clk))
207 			pr_err("%s: failed to register %pOFn %s clock (%ld)\n",
208 			       __func__, np, name, PTR_ERR(clk));
209 		else
210 			cpg->data.clks[i] = clk;
211 	}
212 
213 	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
214 }
215 CLK_OF_DECLARE(sh73a0_cpg_clks, "renesas,sh73a0-cpg-clocks",
216 	       sh73a0_cpg_clocks_init);
217