xref: /openbmc/linux/arch/sh/kernel/cpu/clock-cpg.c (revision fd589a8f)
1 #include <linux/clk.h>
2 #include <linux/compiler.h>
3 #include <linux/slab.h>
4 #include <linux/io.h>
5 #include <asm/clock.h>
6 
7 static int sh_clk_mstp32_enable(struct clk *clk)
8 {
9 	__raw_writel(__raw_readl(clk->enable_reg) & ~(1 << clk->enable_bit),
10 		     clk->enable_reg);
11 	return 0;
12 }
13 
14 static void sh_clk_mstp32_disable(struct clk *clk)
15 {
16 	__raw_writel(__raw_readl(clk->enable_reg) | (1 << clk->enable_bit),
17 		     clk->enable_reg);
18 }
19 
20 static struct clk_ops sh_clk_mstp32_clk_ops = {
21 	.enable		= sh_clk_mstp32_enable,
22 	.disable	= sh_clk_mstp32_disable,
23 	.recalc		= followparent_recalc,
24 };
25 
26 int __init sh_clk_mstp32_register(struct clk *clks, int nr)
27 {
28 	struct clk *clkp;
29 	int ret = 0;
30 	int k;
31 
32 	for (k = 0; !ret && (k < nr); k++) {
33 		clkp = clks + k;
34 		clkp->ops = &sh_clk_mstp32_clk_ops;
35 		ret |= clk_register(clkp);
36 	}
37 
38 	return ret;
39 }
40 
41 static long sh_clk_div_round_rate(struct clk *clk, unsigned long rate)
42 {
43 	return clk_rate_table_round(clk, clk->freq_table, rate);
44 }
45 
46 static int sh_clk_div6_divisors[64] = {
47 	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
48 	17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32,
49 	33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
50 	49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64
51 };
52 
53 static struct clk_div_mult_table sh_clk_div6_table = {
54 	.divisors = sh_clk_div6_divisors,
55 	.nr_divisors = ARRAY_SIZE(sh_clk_div6_divisors),
56 };
57 
58 static unsigned long sh_clk_div6_recalc(struct clk *clk)
59 {
60 	struct clk_div_mult_table *table = &sh_clk_div6_table;
61 	unsigned int idx;
62 
63 	clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
64 			     table, NULL);
65 
66 	idx = __raw_readl(clk->enable_reg) & 0x003f;
67 
68 	return clk->freq_table[idx].frequency;
69 }
70 
71 static int sh_clk_div6_set_rate(struct clk *clk,
72 				unsigned long rate, int algo_id)
73 {
74 	unsigned long value;
75 	int idx;
76 
77 	idx = clk_rate_table_find(clk, clk->freq_table, rate);
78 	if (idx < 0)
79 		return idx;
80 
81 	value = __raw_readl(clk->enable_reg);
82 	value &= ~0x3f;
83 	value |= idx;
84 	__raw_writel(value, clk->enable_reg);
85 	return 0;
86 }
87 
88 static int sh_clk_div6_enable(struct clk *clk)
89 {
90 	unsigned long value;
91 	int ret;
92 
93 	ret = sh_clk_div6_set_rate(clk, clk->rate, 0);
94 	if (ret == 0) {
95 		value = __raw_readl(clk->enable_reg);
96 		value &= ~0x100; /* clear stop bit to enable clock */
97 		__raw_writel(value, clk->enable_reg);
98 	}
99 	return ret;
100 }
101 
102 static void sh_clk_div6_disable(struct clk *clk)
103 {
104 	unsigned long value;
105 
106 	value = __raw_readl(clk->enable_reg);
107 	value |= 0x100; /* stop clock */
108 	value |= 0x3f; /* VDIV bits must be non-zero, overwrite divider */
109 	__raw_writel(value, clk->enable_reg);
110 }
111 
112 static struct clk_ops sh_clk_div6_clk_ops = {
113 	.recalc		= sh_clk_div6_recalc,
114 	.round_rate	= sh_clk_div_round_rate,
115 	.set_rate	= sh_clk_div6_set_rate,
116 	.enable		= sh_clk_div6_enable,
117 	.disable	= sh_clk_div6_disable,
118 };
119 
120 int __init sh_clk_div6_register(struct clk *clks, int nr)
121 {
122 	struct clk *clkp;
123 	void *freq_table;
124 	int nr_divs = sh_clk_div6_table.nr_divisors;
125 	int freq_table_size = sizeof(struct cpufreq_frequency_table);
126 	int ret = 0;
127 	int k;
128 
129 	freq_table_size *= (nr_divs + 1);
130 	freq_table = kzalloc(freq_table_size * nr, GFP_KERNEL);
131 	if (!freq_table) {
132 		pr_err("sh_clk_div6_register: unable to alloc memory\n");
133 		return -ENOMEM;
134 	}
135 
136 	for (k = 0; !ret && (k < nr); k++) {
137 		clkp = clks + k;
138 
139 		clkp->ops = &sh_clk_div6_clk_ops;
140 		clkp->id = -1;
141 		clkp->freq_table = freq_table + (k * freq_table_size);
142 		clkp->freq_table[nr_divs].frequency = CPUFREQ_TABLE_END;
143 
144 		ret = clk_register(clkp);
145 	}
146 
147 	return ret;
148 }
149 
150 static unsigned long sh_clk_div4_recalc(struct clk *clk)
151 {
152 	struct clk_div_mult_table *table = clk->priv;
153 	unsigned int idx;
154 
155 	clk_rate_table_build(clk, clk->freq_table, table->nr_divisors,
156 			     table, &clk->arch_flags);
157 
158 	idx = (__raw_readl(clk->enable_reg) >> clk->enable_bit) & 0x000f;
159 
160 	return clk->freq_table[idx].frequency;
161 }
162 
163 static struct clk_ops sh_clk_div4_clk_ops = {
164 	.recalc		= sh_clk_div4_recalc,
165 	.round_rate	= sh_clk_div_round_rate,
166 };
167 
168 int __init sh_clk_div4_register(struct clk *clks, int nr,
169 				struct clk_div_mult_table *table)
170 {
171 	struct clk *clkp;
172 	void *freq_table;
173 	int nr_divs = table->nr_divisors;
174 	int freq_table_size = sizeof(struct cpufreq_frequency_table);
175 	int ret = 0;
176 	int k;
177 
178 	freq_table_size *= (nr_divs + 1);
179 	freq_table = kzalloc(freq_table_size * nr, GFP_KERNEL);
180 	if (!freq_table) {
181 		pr_err("sh_clk_div4_register: unable to alloc memory\n");
182 		return -ENOMEM;
183 	}
184 
185 	for (k = 0; !ret && (k < nr); k++) {
186 		clkp = clks + k;
187 
188 		clkp->ops = &sh_clk_div4_clk_ops;
189 		clkp->id = -1;
190 		clkp->priv = table;
191 
192 		clkp->freq_table = freq_table + (k * freq_table_size);
193 		clkp->freq_table[nr_divs].frequency = CPUFREQ_TABLE_END;
194 
195 		ret = clk_register(clkp);
196 	}
197 
198 	return ret;
199 }
200 
201 #ifdef CONFIG_SH_CLK_CPG_LEGACY
202 static struct clk master_clk = {
203 	.name		= "master_clk",
204 	.flags		= CLK_ENABLE_ON_INIT,
205 	.rate		= CONFIG_SH_PCLK_FREQ,
206 };
207 
208 static struct clk peripheral_clk = {
209 	.name		= "peripheral_clk",
210 	.parent		= &master_clk,
211 	.flags		= CLK_ENABLE_ON_INIT,
212 };
213 
214 static struct clk bus_clk = {
215 	.name		= "bus_clk",
216 	.parent		= &master_clk,
217 	.flags		= CLK_ENABLE_ON_INIT,
218 };
219 
220 static struct clk cpu_clk = {
221 	.name		= "cpu_clk",
222 	.parent		= &master_clk,
223 	.flags		= CLK_ENABLE_ON_INIT,
224 };
225 
226 /*
227  * The ordering of these clocks matters, do not change it.
228  */
229 static struct clk *onchip_clocks[] = {
230 	&master_clk,
231 	&peripheral_clk,
232 	&bus_clk,
233 	&cpu_clk,
234 };
235 
236 int __init __deprecated cpg_clk_init(void)
237 {
238 	int i, ret = 0;
239 
240 	for (i = 0; i < ARRAY_SIZE(onchip_clocks); i++) {
241 		struct clk *clk = onchip_clocks[i];
242 		arch_init_clk_ops(&clk->ops, i);
243 		if (clk->ops)
244 			ret |= clk_register(clk);
245 	}
246 
247 	return ret;
248 }
249 
250 /*
251  * Placeholder for compatability, until the lazy CPUs do this
252  * on their own.
253  */
254 int __init __weak arch_clk_init(void)
255 {
256 	return cpg_clk_init();
257 }
258 #endif /* CONFIG_SH_CPG_CLK_LEGACY */
259