xref: /openbmc/linux/drivers/clk/clk-clps711x.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Cirrus Logic CLPS711X CLK driver
4  *
5  *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
6  */
7 
8 #include <linux/clk-provider.h>
9 #include <linux/clkdev.h>
10 #include <linux/io.h>
11 #include <linux/ioport.h>
12 #include <linux/of_address.h>
13 #include <linux/slab.h>
14 #include <linux/mfd/syscon/clps711x.h>
15 
16 #include <dt-bindings/clock/clps711x-clock.h>
17 
18 #define CLPS711X_SYSCON1	(0x0100)
19 #define CLPS711X_SYSCON2	(0x1100)
20 #define CLPS711X_SYSFLG2	(CLPS711X_SYSCON2 + SYSFLG_OFFSET)
21 #define CLPS711X_PLLR		(0xa5a8)
22 
23 #define CLPS711X_EXT_FREQ	(13000000)
24 #define CLPS711X_OSC_FREQ	(3686400)
25 
26 static const struct clk_div_table spi_div_table[] = {
27 	{ .val = 0, .div = 32, },
28 	{ .val = 1, .div = 8, },
29 	{ .val = 2, .div = 2, },
30 	{ .val = 3, .div = 1, },
31 	{ /* sentinel */ }
32 };
33 
34 static const struct clk_div_table timer_div_table[] = {
35 	{ .val = 0, .div = 256, },
36 	{ .val = 1, .div = 1, },
37 	{ /* sentinel */ }
38 };
39 
40 struct clps711x_clk {
41 	spinlock_t			lock;
42 	struct clk_hw_onecell_data	clk_data;
43 };
44 
45 static void __init clps711x_clk_init_dt(struct device_node *np)
46 {
47 	u32 tmp, f_cpu, f_pll, f_bus, f_tim, f_pwm, f_spi, fref = 0;
48 	struct clps711x_clk *clps711x_clk;
49 	void __iomem *base;
50 
51 	WARN_ON(of_property_read_u32(np, "startup-frequency", &fref));
52 
53 	base = of_iomap(np, 0);
54 	BUG_ON(!base);
55 
56 	clps711x_clk = kzalloc(struct_size(clps711x_clk, clk_data.hws,
57 					   CLPS711X_CLK_MAX),
58 			       GFP_KERNEL);
59 	BUG_ON(!clps711x_clk);
60 
61 	spin_lock_init(&clps711x_clk->lock);
62 
63 	/* Read PLL multiplier value and sanity check */
64 	tmp = readl(base + CLPS711X_PLLR) >> 24;
65 	if (((tmp >= 10) && (tmp <= 50)) || !fref)
66 		f_pll = DIV_ROUND_UP(CLPS711X_OSC_FREQ * tmp, 2);
67 	else
68 		f_pll = fref;
69 
70 	tmp = readl(base + CLPS711X_SYSFLG2);
71 	if (tmp & SYSFLG2_CKMODE) {
72 		f_cpu = CLPS711X_EXT_FREQ;
73 		f_bus = CLPS711X_EXT_FREQ;
74 		f_spi = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 96);
75 		f_pll = 0;
76 		f_pwm = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 128);
77 	} else {
78 		f_cpu = f_pll;
79 		if (f_cpu > 36864000)
80 			f_bus = DIV_ROUND_UP(f_cpu, 2);
81 		else
82 			f_bus = 36864000 / 2;
83 		f_spi = DIV_ROUND_CLOSEST(f_cpu, 576);
84 		f_pwm = DIV_ROUND_CLOSEST(f_cpu, 768);
85 	}
86 
87 	if (tmp & SYSFLG2_CKMODE) {
88 		if (readl(base + CLPS711X_SYSCON2) & SYSCON2_OSTB)
89 			f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26);
90 		else
91 			f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24);
92 	} else
93 		f_tim = DIV_ROUND_CLOSEST(f_cpu, 144);
94 
95 	tmp = readl(base + CLPS711X_SYSCON1);
96 	/* Timer1 in free running mode.
97 	 * Counter will wrap around to 0xffff when it underflows
98 	 * and will continue to count down.
99 	 */
100 	tmp &= ~(SYSCON1_TC1M | SYSCON1_TC1S);
101 	/* Timer2 in prescale mode.
102 	 * Value writen is automatically re-loaded when
103 	 * the counter underflows.
104 	 */
105 	tmp |= SYSCON1_TC2M | SYSCON1_TC2S;
106 	writel(tmp, base + CLPS711X_SYSCON1);
107 
108 	clps711x_clk->clk_data.hws[CLPS711X_CLK_DUMMY] =
109 		clk_hw_register_fixed_rate(NULL, "dummy", NULL, 0, 0);
110 	clps711x_clk->clk_data.hws[CLPS711X_CLK_CPU] =
111 		clk_hw_register_fixed_rate(NULL, "cpu", NULL, 0, f_cpu);
112 	clps711x_clk->clk_data.hws[CLPS711X_CLK_BUS] =
113 		clk_hw_register_fixed_rate(NULL, "bus", NULL, 0, f_bus);
114 	clps711x_clk->clk_data.hws[CLPS711X_CLK_PLL] =
115 		clk_hw_register_fixed_rate(NULL, "pll", NULL, 0, f_pll);
116 	clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMERREF] =
117 		clk_hw_register_fixed_rate(NULL, "timer_ref", NULL, 0, f_tim);
118 	clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER1] =
119 		clk_hw_register_divider_table(NULL, "timer1", "timer_ref", 0,
120 					   base + CLPS711X_SYSCON1, 5, 1, 0,
121 					   timer_div_table, &clps711x_clk->lock);
122 	clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER2] =
123 		clk_hw_register_divider_table(NULL, "timer2", "timer_ref", 0,
124 					   base + CLPS711X_SYSCON1, 7, 1, 0,
125 					   timer_div_table, &clps711x_clk->lock);
126 	clps711x_clk->clk_data.hws[CLPS711X_CLK_PWM] =
127 		clk_hw_register_fixed_rate(NULL, "pwm", NULL, 0, f_pwm);
128 	clps711x_clk->clk_data.hws[CLPS711X_CLK_SPIREF] =
129 		clk_hw_register_fixed_rate(NULL, "spi_ref", NULL, 0, f_spi);
130 	clps711x_clk->clk_data.hws[CLPS711X_CLK_SPI] =
131 		clk_hw_register_divider_table(NULL, "spi", "spi_ref", 0,
132 					   base + CLPS711X_SYSCON1, 16, 2, 0,
133 					   spi_div_table, &clps711x_clk->lock);
134 	clps711x_clk->clk_data.hws[CLPS711X_CLK_UART] =
135 		clk_hw_register_fixed_factor(NULL, "uart", "bus", 0, 1, 10);
136 	clps711x_clk->clk_data.hws[CLPS711X_CLK_TICK] =
137 		clk_hw_register_fixed_rate(NULL, "tick", NULL, 0, 64);
138 	for (tmp = 0; tmp < CLPS711X_CLK_MAX; tmp++)
139 		if (IS_ERR(clps711x_clk->clk_data.hws[tmp]))
140 			pr_err("clk %i: register failed with %ld\n",
141 			       tmp, PTR_ERR(clps711x_clk->clk_data.hws[tmp]));
142 
143 	clps711x_clk->clk_data.num = CLPS711X_CLK_MAX;
144 	of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
145 			       &clps711x_clk->clk_data);
146 }
147 CLK_OF_DECLARE(clps711x, "cirrus,ep7209-clk", clps711x_clk_init_dt);
148