aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-ep93xx/clock.c
blob: 755e981968b70423a048934f3287e7ed5d0caa7a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
/*
 * arch/arm/mach-ep93xx/clock.c
 * Clock control for Cirrus EP93xx chips.
 *
 * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/io.h>

#include <asm/clkdev.h>
#include <asm/div64.h>
#include <mach/hardware.h>


/*
 * The EP93xx has two external crystal oscillators.  To generate the
 * required high-frequency clocks, the processor uses two phase-locked-
 * loops (PLLs) to multiply the incoming external clock signal to much
 * higher frequencies that are then divided down by programmable dividers
 * to produce the needed clocks.  The PLLs operate independently of one
 * another.
 */
#define EP93XX_EXT_CLK_RATE	14745600
#define EP93XX_EXT_RTC_RATE	32768


struct clk {
	unsigned long	rate;
	int		users;
	int		sw_locked;
	u32		enable_reg;
	u32		enable_mask;

	unsigned long	(*get_rate)(struct clk *clk);
};


static unsigned long get_uart_rate(struct clk *clk);


static struct clk clk_uart1 = {
	.sw_locked	= 1,
	.enable_reg	= EP93XX_SYSCON_DEVICE_CONFIG,
	.enable_mask	= EP93XX_SYSCON_DEVICE_CONFIG_U1EN,
	.get_rate	= get_uart_rate,
};
static struct clk clk_uart2 = {
	.sw_locked	= 1,
	.enable_reg	= EP93XX_SYSCON_DEVICE_CONFIG,
	.enable_mask	= EP93XX_SYSCON_DEVICE_CONFIG_U2EN,
	.get_rate	= get_uart_rate,
};
static struct clk clk_uart3 = {
	.sw_locked	= 1,
	.enable_reg	= EP93XX_SYSCON_DEVICE_CONFIG,
	.enable_mask	= EP93XX_SYSCON_DEVICE_CONFIG_U3EN,
	.get_rate	= get_uart_rate,
};
static struct clk clk_pll1;
static struct clk clk_f;
static struct clk clk_h;
static struct clk clk_p;
static struct clk clk_pll2;
static struct clk clk_usb_host = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_USH_EN,
};

/* DMA Clocks */
static struct clk clk_m2p0 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P0,
};
static struct clk clk_m2p1 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P1,
};
static struct clk clk_m2p2 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P2,
};
static struct clk clk_m2p3 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P3,
};
static struct clk clk_m2p4 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P4,
};
static struct clk clk_m2p5 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P5,
};
static struct clk clk_m2p6 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P6,
};
static struct clk clk_m2p7 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P7,
};
static struct clk clk_m2p8 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P8,
};
static struct clk clk_m2p9 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2P9,
};
static struct clk clk_m2m0 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2M0,
};
static struct clk clk_m2m1 = {
	.enable_reg	= EP93XX_SYSCON_PWRCNT,
	.enable_mask	= EP93XX_SYSCON_PWRCNT_DMA_M2M1,
};

#define INIT_CK(dev,con,ck)					\
	{ .dev_id = dev, .con_id = con, .clk = ck }

static struct clk_lookup clocks[] = {
	INIT_CK("apb:uart1", NULL, &clk_uart1),
	INIT_CK("apb:uart2", NULL, &clk_uart2),
	INIT_CK("apb:uart3", NULL, &clk_uart3),
	INIT_CK(NULL, "pll1", &clk_pll1),
	INIT_CK(NULL, "fclk", &clk_f),
	INIT_CK(NULL, "hclk", &clk_h),
	INIT_CK(NULL, "pclk", &clk_p),
	INIT_CK(NULL, "pll2", &clk_pll2),
	INIT_CK("ep93xx-ohci", NULL, &clk_usb_host),
	INIT_CK(NULL, "m2p0", &clk_m2p0),
	INIT_CK(NULL, "m2p1", &clk_m2p1),
	INIT_CK(NULL, "m2p2", &clk_m2p2),
	INIT_CK(NULL, "m2p3", &clk_m2p3),
	INIT_CK(NULL, "m2p4", &clk_m2p4),
	INIT_CK(NULL, "m2p5", &clk_m2p5),
	INIT_CK(NULL, "m2p6", &clk_m2p6),
	INIT_CK(NULL, "m2p7", &clk_m2p7),
	INIT_CK(NULL, "m2p8", &clk_m2p8),
	INIT_CK(NULL, "m2p9", &clk_m2p9),
	INIT_CK(NULL, "m2m0", &clk_m2m0),
	INIT_CK(NULL, "m2m1", &clk_m2m1),
};


int clk_enable(struct clk *clk)
{
	if (!clk->users++ && clk->enable_reg) {
		u32 value;

		value = __raw_readl(clk->enable_reg);
		if (clk->sw_locked)
			__raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
		__raw_writel(value | clk->enable_mask, clk->enable_reg);
	}

	return 0;
}
EXPORT_SYMBOL(clk_enable);

void clk_disable(struct clk *clk)
{
	if (!--clk->users && clk->enable_reg) {
		u32 value;

		value = __raw_readl(clk->enable_reg);
		if (clk->sw_locked)
			__raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
		__raw_writel(value & ~clk->enable_mask, clk->enable_reg);
	}
}
EXPORT_SYMBOL(clk_disable);

static unsigned long get_uart_rate(struct clk *clk)
{
	u32 value;

	value = __raw_readl(EP93XX_SYSCON_CLOCK_CONTROL);
	if (value & EP93XX_SYSCON_CLOCK_UARTBAUD)
		return EP93XX_EXT_CLK_RATE;
	else
		return EP93XX_EXT_CLK_RATE / 2;
}

unsigned long clk_get_rate(struct clk *clk)
{
	if (clk->get_rate)
		return clk->get_rate(clk);

	return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);


static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 };
static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 };
static char pclk_divisors[] = { 1, 2, 4, 8 };

/*
 * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS
 */
static unsigned long calc_pll_rate(u32 config_word)
{
	unsigned long long rate;
	int i;

	rate = EP93XX_EXT_CLK_RATE;
	rate *= ((config_word >> 11) & 0x1f) + 1;		/* X1FBD */
	rate *= ((config_word >> 5) & 0x3f) + 1;		/* X2FBD */
	do_div(rate, (config_word & 0x1f) + 1);			/* X2IPD */
	for (i = 0; i < ((config_word >> 16) & 3); i++)		/* PS */
		rate >>= 1;

	return (unsigned long)rate;
}

static void __init ep93xx_dma_clock_init(void)
{
	clk_m2p0.rate = clk_h.rate;
	clk_m2p1.rate = clk_h.rate;
	clk_m2p2.rate = clk_h.rate;
	clk_m2p3.rate = clk_h.rate;
	clk_m2p4.rate = clk_h.rate;
	clk_m2p5.rate = clk_h.rate;
	clk_m2p6.rate = clk_h.rate;
	clk_m2p7.rate = clk_h.rate;
	clk_m2p8.rate = clk_h.rate;
	clk_m2p9.rate = clk_h.rate;
	clk_m2m0.rate = clk_h.rate;
	clk_m2m1.rate = clk_h.rate;
}

static int __init ep93xx_clock_init(void)
{
	u32 value;
	int i;

	value = __raw_readl(EP93XX_SYSCON_CLOCK_SET1);
	if (!(value & 0x00800000)) {			/* PLL1 bypassed?  */
		clk_pll1.rate = EP93XX_EXT_CLK_RATE;
	} else {
		clk_pll1.rate = calc_pll_rate(value);
	}
	clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7];
	clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7];
	clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3];
	ep93xx_dma_clock_init();

	value = __raw_readl(EP93XX_SYSCON_CLOCK_SET2);
	if (!(value & 0x00080000)) {			/* PLL2 bypassed?  */
		clk_pll2.rate = EP93XX_EXT_CLK_RATE;
	} else if (value & 0x00040000) {		/* PLL2 enabled?  */
		clk_pll2.rate = calc_pll_rate(value);
	} else {
		clk_pll2.rate = 0;
	}
	clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);

	printk(KERN_INFO "ep93xx: PLL1 running at %ld MHz, PLL2 at %ld MHz\n",
		clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
	printk(KERN_INFO "ep93xx: FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
		clk_f.rate / 1000000, clk_h.rate / 1000000,
		clk_p.rate / 1000000);

	for (i = 0; i < ARRAY_SIZE(clocks); i++)
		clkdev_add(&clocks[i]);
	return 0;
}
arch_initcall(ep93xx_clock_init);