1 /*
2  * arch/sh/kernel/cpu/sh2a/clock-sh7264.c
3  *
4  * SH7264 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 /* SH7264 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 #define STBCR8		0xfffe041c
26 
27 static const unsigned int pll1rate[] = {8, 12};
28 
29 static unsigned int pll1_div;
30 
31 /* Fixed 32 KHz root clock for RTC */
32 static struct clk r_clk = {
33 	.rate           = 32768,
34 };
35 
36 /*
37  * Default rate for the root input clock, reset this with clk_set_rate()
38  * from the platform code.
39  */
40 static struct clk extal_clk = {
41 	.rate		= 18000000,
42 };
43 
44 static unsigned long pll_recalc(struct clk *clk)
45 {
46 	unsigned long rate = clk->parent->rate / pll1_div;
47 	return rate * pll1rate[(__raw_readw(FRQCR) >> 8) & 1];
48 }
49 
50 static struct sh_clk_ops pll_clk_ops = {
51 	.recalc		= pll_recalc,
52 };
53 
54 static struct clk pll_clk = {
55 	.ops		= &pll_clk_ops,
56 	.parent		= &extal_clk,
57 	.flags		= CLK_ENABLE_ON_INIT,
58 };
59 
60 struct clk *main_clks[] = {
61 	&r_clk,
62 	&extal_clk,
63 	&pll_clk,
64 };
65 
66 static int div2[] = { 1, 2, 3, 4, 6, 8, 12 };
67 
68 static struct clk_div_mult_table div4_div_mult_table = {
69 	.divisors = div2,
70 	.nr_divisors = ARRAY_SIZE(div2),
71 };
72 
73 static struct clk_div4_table div4_table = {
74 	.div_mult_table = &div4_div_mult_table,
75 };
76 
77 enum { DIV4_I, DIV4_P,
78        DIV4_NR };
79 
80 #define DIV4(_reg, _bit, _mask, _flags) \
81   SH_CLK_DIV4(&pll_clk, _reg, _bit, _mask, _flags)
82 
83 /* The mask field specifies the div2 entries that are valid */
84 struct clk div4_clks[DIV4_NR] = {
85 	[DIV4_I] = DIV4(FRQCR, 4, 0x7,  CLK_ENABLE_REG_16BIT
86 					| CLK_ENABLE_ON_INIT),
87 	[DIV4_P] = DIV4(FRQCR, 0, 0x78, CLK_ENABLE_REG_16BIT),
88 };
89 
90 enum {	MSTP77, MSTP74, MSTP72,
91 	MSTP60,
92 	MSTP35, MSTP34, MSTP33, MSTP32, MSTP30,
93 	MSTP_NR };
94 
95 static struct clk mstp_clks[MSTP_NR] = {
96 	[MSTP77] = SH_CLK_MSTP8(&div4_clks[DIV4_P], STBCR7, 7, 0), /* SCIF */
97 	[MSTP74] = SH_CLK_MSTP8(&div4_clks[DIV4_P], STBCR7, 4, 0), /* VDC */
98 	[MSTP72] = SH_CLK_MSTP8(&div4_clks[DIV4_P], STBCR7, 2, 0), /* CMT */
99 	[MSTP60] = SH_CLK_MSTP8(&div4_clks[DIV4_P], STBCR6, 0, 0), /* USB */
100 	[MSTP35] = SH_CLK_MSTP8(&div4_clks[DIV4_P], STBCR3, 6, 0), /* MTU2 */
101 	[MSTP34] = SH_CLK_MSTP8(&div4_clks[DIV4_P], STBCR3, 4, 0), /* SDHI0 */
102 	[MSTP33] = SH_CLK_MSTP8(&div4_clks[DIV4_P], STBCR3, 3, 0), /* SDHI1 */
103 	[MSTP32] = SH_CLK_MSTP8(&div4_clks[DIV4_P], STBCR3, 2, 0), /* ADC */
104 	[MSTP30] = SH_CLK_MSTP8(&r_clk, STBCR3, 0, 0),	/* RTC */
105 };
106 
107 static struct clk_lookup lookups[] = {
108 	/* main clocks */
109 	CLKDEV_CON_ID("rclk", &r_clk),
110 	CLKDEV_CON_ID("extal", &extal_clk),
111 	CLKDEV_CON_ID("pll_clk", &pll_clk),
112 
113 	/* DIV4 clocks */
114 	CLKDEV_CON_ID("cpu_clk", &div4_clks[DIV4_I]),
115 	CLKDEV_CON_ID("peripheral_clk", &div4_clks[DIV4_P]),
116 
117 	/* MSTP clocks */
118 	CLKDEV_CON_ID("sci_ick", &mstp_clks[MSTP77]),
119 	CLKDEV_CON_ID("vdc3", &mstp_clks[MSTP74]),
120 	CLKDEV_CON_ID("cmt_fck", &mstp_clks[MSTP72]),
121 	CLKDEV_CON_ID("usb0", &mstp_clks[MSTP60]),
122 	CLKDEV_CON_ID("mtu2_fck", &mstp_clks[MSTP35]),
123 	CLKDEV_CON_ID("sdhi0", &mstp_clks[MSTP34]),
124 	CLKDEV_CON_ID("sdhi1", &mstp_clks[MSTP33]),
125 	CLKDEV_CON_ID("adc0", &mstp_clks[MSTP32]),
126 	CLKDEV_CON_ID("rtc0", &mstp_clks[MSTP30]),
127 };
128 
129 int __init arch_clk_init(void)
130 {
131 	int k, ret = 0;
132 
133 	if (test_mode_pin(MODE_PIN0)) {
134 		if (test_mode_pin(MODE_PIN1))
135 			pll1_div = 3;
136 		else
137 			pll1_div = 4;
138 	} else
139 		pll1_div = 1;
140 
141 	for (k = 0; !ret && (k < ARRAY_SIZE(main_clks)); k++)
142 		ret = clk_register(main_clks[k]);
143 
144 	clkdev_add_table(lookups, ARRAY_SIZE(lookups));
145 
146 	if (!ret)
147 		ret = sh_clk_div4_register(div4_clks, DIV4_NR, &div4_table);
148 
149 	if (!ret)
150 		ret = sh_clk_mstp_register(mstp_clks, MSTP_NR);
151 
152 	return ret;
153 }
154