1 /*
2 * Cirrus Logic CLPS711X CLK driver
3 *
4 * Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12 #include <linux/clk.h>
13 #include <linux/clk-provider.h>
14 #include <linux/clkdev.h>
15 #include <linux/io.h>
16 #include <linux/ioport.h>
17 #include <linux/of_address.h>
18 #include <linux/slab.h>
19 #include <linux/mfd/syscon/clps711x.h>
20
21 #include <dt-bindings/clock/clps711x-clock.h>
22
23 #define CLPS711X_SYSCON1 (0x0100)
24 #define CLPS711X_SYSCON2 (0x1100)
25 #define CLPS711X_SYSFLG2 (CLPS711X_SYSCON2 + SYSFLG_OFFSET)
26 #define CLPS711X_PLLR (0xa5a8)
27
28 #define CLPS711X_EXT_FREQ (13000000)
29 #define CLPS711X_OSC_FREQ (3686400)
30
31 static const struct clk_div_table spi_div_table[] = {
32 { .val = 0, .div = 32, },
33 { .val = 1, .div = 8, },
34 { .val = 2, .div = 2, },
35 { .val = 3, .div = 1, },
36 };
37
38 static const struct clk_div_table timer_div_table[] = {
39 { .val = 0, .div = 256, },
40 { .val = 1, .div = 1, },
41 };
42
43 struct clps711x_clk {
44 struct clk_onecell_data clk_data;
45 spinlock_t lock;
46 struct clk *clks[CLPS711X_CLK_MAX];
47 };
48
_clps711x_clk_init(void __iomem * base,u32 fref)49 static struct clps711x_clk * __init _clps711x_clk_init(void __iomem *base,
50 u32 fref)
51 {
52 u32 tmp, f_cpu, f_pll, f_bus, f_tim, f_pwm, f_spi;
53 struct clps711x_clk *clps711x_clk;
54 unsigned i;
55
56 if (!base)
57 return ERR_PTR(-ENOMEM);
58
59 clps711x_clk = kzalloc(sizeof(*clps711x_clk), GFP_KERNEL);
60 if (!clps711x_clk)
61 return ERR_PTR(-ENOMEM);
62
63 spin_lock_init(&clps711x_clk->lock);
64
65 /* Read PLL multiplier value and sanity check */
66 tmp = readl(base + CLPS711X_PLLR) >> 24;
67 if (((tmp >= 10) && (tmp <= 50)) || !fref)
68 f_pll = DIV_ROUND_UP(CLPS711X_OSC_FREQ * tmp, 2);
69 else
70 f_pll = fref;
71
72 tmp = readl(base + CLPS711X_SYSFLG2);
73 if (tmp & SYSFLG2_CKMODE) {
74 f_cpu = CLPS711X_EXT_FREQ;
75 f_bus = CLPS711X_EXT_FREQ;
76 f_spi = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 96);
77 f_pll = 0;
78 f_pwm = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 128);
79 } else {
80 f_cpu = f_pll;
81 if (f_cpu > 36864000)
82 f_bus = DIV_ROUND_UP(f_cpu, 2);
83 else
84 f_bus = 36864000 / 2;
85 f_spi = DIV_ROUND_CLOSEST(f_cpu, 576);
86 f_pwm = DIV_ROUND_CLOSEST(f_cpu, 768);
87 }
88
89 if (tmp & SYSFLG2_CKMODE) {
90 if (readl(base + CLPS711X_SYSCON2) & SYSCON2_OSTB)
91 f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26);
92 else
93 f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24);
94 } else
95 f_tim = DIV_ROUND_CLOSEST(f_cpu, 144);
96
97 tmp = readl(base + CLPS711X_SYSCON1);
98 /* Timer1 in free running mode.
99 * Counter will wrap around to 0xffff when it underflows
100 * and will continue to count down.
101 */
102 tmp &= ~(SYSCON1_TC1M | SYSCON1_TC1S);
103 /* Timer2 in prescale mode.
104 * Value writen is automatically re-loaded when
105 * the counter underflows.
106 */
107 tmp |= SYSCON1_TC2M | SYSCON1_TC2S;
108 writel(tmp, base + CLPS711X_SYSCON1);
109
110 clps711x_clk->clks[CLPS711X_CLK_DUMMY] =
111 clk_register_fixed_rate(NULL, "dummy", NULL, CLK_IS_ROOT, 0);
112 clps711x_clk->clks[CLPS711X_CLK_CPU] =
113 clk_register_fixed_rate(NULL, "cpu", NULL, CLK_IS_ROOT, f_cpu);
114 clps711x_clk->clks[CLPS711X_CLK_BUS] =
115 clk_register_fixed_rate(NULL, "bus", NULL, CLK_IS_ROOT, f_bus);
116 clps711x_clk->clks[CLPS711X_CLK_PLL] =
117 clk_register_fixed_rate(NULL, "pll", NULL, CLK_IS_ROOT, f_pll);
118 clps711x_clk->clks[CLPS711X_CLK_TIMERREF] =
119 clk_register_fixed_rate(NULL, "timer_ref", NULL, CLK_IS_ROOT,
120 f_tim);
121 clps711x_clk->clks[CLPS711X_CLK_TIMER1] =
122 clk_register_divider_table(NULL, "timer1", "timer_ref", 0,
123 base + CLPS711X_SYSCON1, 5, 1, 0,
124 timer_div_table, &clps711x_clk->lock);
125 clps711x_clk->clks[CLPS711X_CLK_TIMER2] =
126 clk_register_divider_table(NULL, "timer2", "timer_ref", 0,
127 base + CLPS711X_SYSCON1, 7, 1, 0,
128 timer_div_table, &clps711x_clk->lock);
129 clps711x_clk->clks[CLPS711X_CLK_PWM] =
130 clk_register_fixed_rate(NULL, "pwm", NULL, CLK_IS_ROOT, f_pwm);
131 clps711x_clk->clks[CLPS711X_CLK_SPIREF] =
132 clk_register_fixed_rate(NULL, "spi_ref", NULL, CLK_IS_ROOT,
133 f_spi);
134 clps711x_clk->clks[CLPS711X_CLK_SPI] =
135 clk_register_divider_table(NULL, "spi", "spi_ref", 0,
136 base + CLPS711X_SYSCON1, 16, 2, 0,
137 spi_div_table, &clps711x_clk->lock);
138 clps711x_clk->clks[CLPS711X_CLK_UART] =
139 clk_register_fixed_factor(NULL, "uart", "bus", 0, 1, 10);
140 clps711x_clk->clks[CLPS711X_CLK_TICK] =
141 clk_register_fixed_rate(NULL, "tick", NULL, CLK_IS_ROOT, 64);
142
143 for (i = 0; i < CLPS711X_CLK_MAX; i++)
144 if (IS_ERR(clps711x_clk->clks[i]))
145 pr_err("clk %i: register failed with %ld\n",
146 i, PTR_ERR(clps711x_clk->clks[i]));
147
148 return clps711x_clk;
149 }
150
clps711x_clk_init(void __iomem * base)151 void __init clps711x_clk_init(void __iomem *base)
152 {
153 struct clps711x_clk *clps711x_clk;
154
155 clps711x_clk = _clps711x_clk_init(base, 73728000);
156
157 BUG_ON(IS_ERR(clps711x_clk));
158
159 /* Clocksource */
160 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_TIMER1],
161 NULL, "clps711x-timer.0");
162 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_TIMER2],
163 NULL, "clps711x-timer.1");
164
165 /* Drivers */
166 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_PWM],
167 NULL, "clps711x-pwm");
168 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_UART],
169 NULL, "clps711x-uart.0");
170 clk_register_clkdev(clps711x_clk->clks[CLPS711X_CLK_UART],
171 NULL, "clps711x-uart.1");
172 }
173
174 #ifdef CONFIG_OF
clps711x_clk_init_dt(struct device_node * np)175 static void __init clps711x_clk_init_dt(struct device_node *np)
176 {
177 void __iomem *base = of_iomap(np, 0);
178 struct clps711x_clk *clps711x_clk;
179 u32 fref = 0;
180
181 WARN_ON(of_property_read_u32(np, "startup-frequency", &fref));
182
183 clps711x_clk = _clps711x_clk_init(base, fref);
184 BUG_ON(IS_ERR(clps711x_clk));
185
186 clps711x_clk->clk_data.clks = clps711x_clk->clks;
187 clps711x_clk->clk_data.clk_num = CLPS711X_CLK_MAX;
188 of_clk_add_provider(np, of_clk_src_onecell_get,
189 &clps711x_clk->clk_data);
190 }
191 CLK_OF_DECLARE(clps711x, "cirrus,clps711x-clk", clps711x_clk_init_dt);
192 #endif
193