1 /*
2  * arch/sh/kernel/cpu/sh2a/clock-sh7269.c
3  *
4  * SH7269 clock framework support
5  *
6  * Copyright (C) 2012  Phil Edworthy
7  *
8  * This file is subject to the terms and conditions of the GNU General Public
9  * License.  See the file "COPYING" in the main directory of this archive
10  * for more details.
11  */
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/io.h>
15 #include <linux/clkdev.h>
16 #include <asm/clock.h>
17 
18 /* SH7269 registers */
19 #define FRQCR		0xfffe0010
20 #define STBCR3 		0xfffe0408
21 #define STBCR4 		0xfffe040c
22 #define STBCR5 		0xfffe0410
23 #define STBCR6 		0xfffe0414
24 #define STBCR7 		0xfffe0418
25 
26 #define PLL_RATE 20
27 
28 /* Fixed 32 KHz root clock for RTC */
29 static struct clk r_clk = {
30 	.rate           = 32768,
31 };
32 
33 /*
34  * Default rate for the root input clock, reset this with clk_set_rate()
35  * from the platform code.
36  */
37 static struct clk extal_clk = {
38 	.rate		= 13340000,
39 };
40 
41 static unsigned long pll_recalc(struct clk *clk)
42 {
43 	return clk->parent->rate * PLL_RATE;
44 }
45 
46 static struct sh_clk_ops pll_clk_ops = {
47 	.recalc		= pll_recalc,
48 };
49 
50 static struct clk pll_clk = {
51 	.ops		= &pll_clk_ops,
52 	.parent		= &extal_clk,
53 	.flags		= CLK_ENABLE_ON_INIT,
54 };
55 
56 static unsigned long peripheral0_recalc(struct clk *clk)
57 {
58 	return clk->parent->rate / 8;
59 }
60 
61 static struct sh_clk_ops peripheral0_clk_ops = {
62 	.recalc		= peripheral0_recalc,
63 };
64 
65 static struct clk peripheral0_clk = {
66 	.ops		= &peripheral0_clk_ops,
67 	.parent		= &pll_clk,
68 	.flags		= CLK_ENABLE_ON_INIT,
69 };
70 
71 static unsigned long peripheral1_recalc(struct clk *clk)
72 {
73 	return clk->parent->rate / 4;
74 }
75 
76 static struct sh_clk_ops peripheral1_clk_ops = {
77 	.recalc		= peripheral1_recalc,
78 };
79 
80 static struct clk peripheral1_clk = {
81 	.ops		= &peripheral1_clk_ops,
82 	.parent		= &pll_clk,
83 	.flags		= CLK_ENABLE_ON_INIT,
84 };
85 
86 struct clk *main_clks[] = {
87 	&r_clk,
88 	&extal_clk,
89 	&pll_clk,
90 	&peripheral0_clk,
91 	&peripheral1_clk,
92 };
93 
94 static int div2[] = { 1, 2, 0, 4 };
95 
96 static struct clk_div_mult_table div4_div_mult_table = {
97 	.divisors = div2,
98 	.nr_divisors = ARRAY_SIZE(div2),
99 };
100 
101 static struct clk_div4_table div4_table = {
102 	.div_mult_table = &div4_div_mult_table,
103 };
104 
105 enum { DIV4_I, DIV4_B,
106        DIV4_NR };
107 
108 #define DIV4(_reg, _bit, _mask, _flags) \
109   SH_CLK_DIV4(&pll_clk, _reg, _bit, _mask, _flags)
110 
111 /* The mask field specifies the div2 entries that are valid */
112 struct clk div4_clks[DIV4_NR] = {
113 	[DIV4_I]  = DIV4(FRQCR, 8, 0xB, CLK_ENABLE_REG_16BIT
114 					| CLK_ENABLE_ON_INIT),
115 	[DIV4_B]  = DIV4(FRQCR, 4, 0xA, CLK_ENABLE_REG_16BIT
116 					| CLK_ENABLE_ON_INIT),
117 };
118 
119 enum { MSTP72,
120 	MSTP60,
121 	MSTP47, MSTP46, MSTP45, MSTP44, MSTP43, MSTP42, MSTP41, MSTP40,
122 	MSTP35, MSTP32, MSTP30,
123 	MSTP_NR };
124 
125 static struct clk mstp_clks[MSTP_NR] = {
126 	[MSTP72] = SH_CLK_MSTP8(&peripheral0_clk, STBCR7, 2, 0), /* CMT */
127 	[MSTP60] = SH_CLK_MSTP8(&peripheral1_clk, STBCR6, 0, 0), /* USB */
128 	[MSTP47] = SH_CLK_MSTP8(&peripheral1_clk, STBCR4, 7, 0), /* SCIF0 */
129 	[MSTP46] = SH_CLK_MSTP8(&peripheral1_clk, STBCR4, 6, 0), /* SCIF1 */
130 	[MSTP45] = SH_CLK_MSTP8(&peripheral1_clk, STBCR4, 5, 0), /* SCIF2 */
131 	[MSTP44] = SH_CLK_MSTP8(&peripheral1_clk, STBCR4, 4, 0), /* SCIF3 */
132 	[MSTP43] = SH_CLK_MSTP8(&peripheral1_clk, STBCR4, 3, 0), /* SCIF4 */
133 	[MSTP42] = SH_CLK_MSTP8(&peripheral1_clk, STBCR4, 2, 0), /* SCIF5 */
134 	[MSTP41] = SH_CLK_MSTP8(&peripheral1_clk, STBCR4, 1, 0), /* SCIF6 */
135 	[MSTP40] = SH_CLK_MSTP8(&peripheral1_clk, STBCR4, 0, 0), /* SCIF7 */
136 	[MSTP35] = SH_CLK_MSTP8(&peripheral0_clk, STBCR3, 5, 0), /* MTU2 */
137 	[MSTP32] = SH_CLK_MSTP8(&peripheral1_clk, STBCR3, 2, 0), /* ADC */
138 	[MSTP30] = SH_CLK_MSTP8(&r_clk, STBCR3, 0, 0), /* RTC */
139 };
140 
141 static struct clk_lookup lookups[] = {
142 	/* main clocks */
143 	CLKDEV_CON_ID("rclk", &r_clk),
144 	CLKDEV_CON_ID("extal", &extal_clk),
145 	CLKDEV_CON_ID("pll_clk", &pll_clk),
146 	CLKDEV_CON_ID("peripheral_clk", &peripheral1_clk),
147 
148 	/* DIV4 clocks */
149 	CLKDEV_CON_ID("cpu_clk", &div4_clks[DIV4_I]),
150 	CLKDEV_CON_ID("bus_clk", &div4_clks[DIV4_B]),
151 
152 	/* MSTP clocks */
153 	CLKDEV_ICK_ID("sci_fck", "sh-sci.0", &mstp_clks[MSTP47]),
154 	CLKDEV_ICK_ID("sci_fck", "sh-sci.1", &mstp_clks[MSTP46]),
155 	CLKDEV_ICK_ID("sci_fck", "sh-sci.2", &mstp_clks[MSTP45]),
156 	CLKDEV_ICK_ID("sci_fck", "sh-sci.3", &mstp_clks[MSTP44]),
157 	CLKDEV_ICK_ID("sci_fck", "sh-sci.4", &mstp_clks[MSTP43]),
158 	CLKDEV_ICK_ID("sci_fck", "sh-sci.5", &mstp_clks[MSTP42]),
159 	CLKDEV_ICK_ID("sci_fck", "sh-sci.6", &mstp_clks[MSTP41]),
160 	CLKDEV_ICK_ID("sci_fck", "sh-sci.7", &mstp_clks[MSTP40]),
161 	CLKDEV_ICK_ID("fck", "sh-cmt-16.0", &mstp_clks[MSTP72]),
162 	CLKDEV_CON_ID("usb0", &mstp_clks[MSTP60]),
163 	CLKDEV_ICK_ID("fck", "sh-mtu2", &mstp_clks[MSTP35]),
164 	CLKDEV_CON_ID("adc0", &mstp_clks[MSTP32]),
165 	CLKDEV_CON_ID("rtc0", &mstp_clks[MSTP30]),
166 };
167 
168 int __init arch_clk_init(void)
169 {
170 	int k, ret = 0;
171 
172 	for (k = 0; !ret && (k < ARRAY_SIZE(main_clks)); k++)
173 		ret = clk_register(main_clks[k]);
174 
175 	clkdev_add_table(lookups, ARRAY_SIZE(lookups));
176 
177 	if (!ret)
178 		ret = sh_clk_div4_register(div4_clks, DIV4_NR, &div4_table);
179 
180 	if (!ret)
181 		ret = sh_clk_mstp_register(mstp_clks, MSTP_NR);
182 
183 	return ret;
184 }
185