aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/clk/clk-clps711x.c
blob: 50b42e91a13778a9d967ae6e969b87e0b3d69883 (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
/*
 *  Cirrus Logic CLPS711X CLK driver
 *
 *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
 *
 * 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/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/mfd/syscon/clps711x.h>

#include <dt-bindings/clock/clps711x-clock.h>

#define CLPS711X_SYSCON1	(0x0100)
#define CLPS711X_SYSCON2	(0x1100)
#define CLPS711X_SYSFLG2	(CLPS711X_SYSCON2 + SYSFLG_OFFSET)
#define CLPS711X_PLLR		(0xa5a8)

#define CLPS711X_EXT_FREQ	(13000000)
#define CLPS711X_OSC_FREQ	(3686400)

static const struct clk_div_table spi_div_table[] = {
	{ .val = 0, .div = 32, },
	{ .val = 1, .div = 8, },
	{ .val = 2, .div = 2, },
	{ .val = 3, .div = 1, },
	{ /* sentinel */ }
};

static const struct clk_div_table timer_div_table[] = {
	{ .val = 0, .div = 256, },
	{ .val = 1, .div = 1, },
	{ /* sentinel */ }
};

struct clps711x_clk {
	spinlock_t			lock;
	struct clk_hw_onecell_data	clk_data;
};

static struct clps711x_clk * __init _clps711x_clk_init(void __iomem *base,
						       u32 fref)
{
	u32 tmp, f_cpu, f_pll, f_bus, f_tim, f_pwm, f_spi;
	struct clps711x_clk *clps711x_clk;
	unsigned i;

	if (!base)
		return ERR_PTR(-ENOMEM);

	clps711x_clk = kzalloc(struct_size(clps711x_clk, clk_data.hws,
					   CLPS711X_CLK_MAX),
			       GFP_KERNEL);
	if (!clps711x_clk)
		return ERR_PTR(-ENOMEM);

	spin_lock_init(&clps711x_clk->lock);

	/* Read PLL multiplier value and sanity check */
	tmp = readl(base + CLPS711X_PLLR) >> 24;
	if (((tmp >= 10) && (tmp <= 50)) || !fref)
		f_pll = DIV_ROUND_UP(CLPS711X_OSC_FREQ * tmp, 2);
	else
		f_pll = fref;

	tmp = readl(base + CLPS711X_SYSFLG2);
	if (tmp & SYSFLG2_CKMODE) {
		f_cpu = CLPS711X_EXT_FREQ;
		f_bus = CLPS711X_EXT_FREQ;
		f_spi = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 96);
		f_pll = 0;
		f_pwm = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 128);
	} else {
		f_cpu = f_pll;
		if (f_cpu > 36864000)
			f_bus = DIV_ROUND_UP(f_cpu, 2);
		else
			f_bus = 36864000 / 2;
		f_spi = DIV_ROUND_CLOSEST(f_cpu, 576);
		f_pwm = DIV_ROUND_CLOSEST(f_cpu, 768);
	}

	if (tmp & SYSFLG2_CKMODE) {
		if (readl(base + CLPS711X_SYSCON2) & SYSCON2_OSTB)
			f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26);
		else
			f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24);
	} else
		f_tim = DIV_ROUND_CLOSEST(f_cpu, 144);

	tmp = readl(base + CLPS711X_SYSCON1);
	/* Timer1 in free running mode.
	 * Counter will wrap around to 0xffff when it underflows
	 * and will continue to count down.
	 */
	tmp &= ~(SYSCON1_TC1M | SYSCON1_TC1S);
	/* Timer2 in prescale mode.
	 * Value writen is automatically re-loaded when
	 * the counter underflows.
	 */
	tmp |= SYSCON1_TC2M | SYSCON1_TC2S;
	writel(tmp, base + CLPS711X_SYSCON1);

	clps711x_clk->clk_data.hws[CLPS711X_CLK_DUMMY] =
		clk_hw_register_fixed_rate(NULL, "dummy", NULL, 0, 0);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_CPU] =
		clk_hw_register_fixed_rate(NULL, "cpu", NULL, 0, f_cpu);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_BUS] =
		clk_hw_register_fixed_rate(NULL, "bus", NULL, 0, f_bus);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_PLL] =
		clk_hw_register_fixed_rate(NULL, "pll", NULL, 0, f_pll);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMERREF] =
		clk_hw_register_fixed_rate(NULL, "timer_ref", NULL, 0, f_tim);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER1] =
		clk_hw_register_divider_table(NULL, "timer1", "timer_ref", 0,
					   base + CLPS711X_SYSCON1, 5, 1, 0,
					   timer_div_table, &clps711x_clk->lock);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER2] =
		clk_hw_register_divider_table(NULL, "timer2", "timer_ref", 0,
					   base + CLPS711X_SYSCON1, 7, 1, 0,
					   timer_div_table, &clps711x_clk->lock);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_PWM] =
		clk_hw_register_fixed_rate(NULL, "pwm", NULL, 0, f_pwm);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_SPIREF] =
		clk_hw_register_fixed_rate(NULL, "spi_ref", NULL, 0, f_spi);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_SPI] =
		clk_hw_register_divider_table(NULL, "spi", "spi_ref", 0,
					   base + CLPS711X_SYSCON1, 16, 2, 0,
					   spi_div_table, &clps711x_clk->lock);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_UART] =
		clk_hw_register_fixed_factor(NULL, "uart", "bus", 0, 1, 10);
	clps711x_clk->clk_data.hws[CLPS711X_CLK_TICK] =
		clk_hw_register_fixed_rate(NULL, "tick", NULL, 0, 64);
	for (i = 0; i < CLPS711X_CLK_MAX; i++)
		if (IS_ERR(clps711x_clk->clk_data.hws[i]))
			pr_err("clk %i: register failed with %ld\n",
			       i, PTR_ERR(clps711x_clk->clk_data.hws[i]));

	return clps711x_clk;
}

void __init clps711x_clk_init(void __iomem *base)
{
	struct clps711x_clk *clps711x_clk;

	clps711x_clk = _clps711x_clk_init(base, 73728000);

	BUG_ON(IS_ERR(clps711x_clk));

	/* Clocksource */
	clk_hw_register_clkdev(clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER1],
			    NULL, "clps711x-timer.0");
	clk_hw_register_clkdev(clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER2],
			    NULL, "clps711x-timer.1");

	/* Drivers */
	clk_hw_register_clkdev(clps711x_clk->clk_data.hws[CLPS711X_CLK_PWM],
			    NULL, "clps711x-pwm");
	clk_hw_register_clkdev(clps711x_clk->clk_data.hws[CLPS711X_CLK_UART],
			    NULL, "clps711x-uart.0");
	clk_hw_register_clkdev(clps711x_clk->clk_data.hws[CLPS711X_CLK_UART],
			    NULL, "clps711x-uart.1");
}

#ifdef CONFIG_OF
static void __init clps711x_clk_init_dt(struct device_node *np)
{
	void __iomem *base = of_iomap(np, 0);
	struct clps711x_clk *clps711x_clk;
	u32 fref = 0;

	WARN_ON(of_property_read_u32(np, "startup-frequency", &fref));

	clps711x_clk = _clps711x_clk_init(base, fref);
	BUG_ON(IS_ERR(clps711x_clk));

	clps711x_clk->clk_data.num = CLPS711X_CLK_MAX;
	of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
			       &clps711x_clk->clk_data);
}
CLK_OF_DECLARE(clps711x, "cirrus,ep7209-clk", clps711x_clk_init_dt);
#endif