a2c6486ef1708bb387fd88b33e8bbd1fd04c730d
[platform/kernel/linux-rpi.git] / drivers / clk / clk-clps711x.c
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 };
32
33 static const struct clk_div_table timer_div_table[] = {
34         { .val = 0, .div = 256, },
35         { .val = 1, .div = 1, },
36 };
37
38 struct clps711x_clk {
39         spinlock_t                      lock;
40         struct clk_hw_onecell_data      clk_data;
41 };
42
43 static void __init clps711x_clk_init_dt(struct device_node *np)
44 {
45         u32 tmp, f_cpu, f_pll, f_bus, f_tim, f_pwm, f_spi, fref = 0;
46         struct clps711x_clk *clps711x_clk;
47         void __iomem *base;
48
49         WARN_ON(of_property_read_u32(np, "startup-frequency", &fref));
50
51         base = of_iomap(np, 0);
52         BUG_ON(!base);
53
54         clps711x_clk = kzalloc(struct_size(clps711x_clk, clk_data.hws,
55                                            CLPS711X_CLK_MAX),
56                                GFP_KERNEL);
57         BUG_ON(!clps711x_clk);
58
59         spin_lock_init(&clps711x_clk->lock);
60
61         /* Read PLL multiplier value and sanity check */
62         tmp = readl(base + CLPS711X_PLLR) >> 24;
63         if (((tmp >= 10) && (tmp <= 50)) || !fref)
64                 f_pll = DIV_ROUND_UP(CLPS711X_OSC_FREQ * tmp, 2);
65         else
66                 f_pll = fref;
67
68         tmp = readl(base + CLPS711X_SYSFLG2);
69         if (tmp & SYSFLG2_CKMODE) {
70                 f_cpu = CLPS711X_EXT_FREQ;
71                 f_bus = CLPS711X_EXT_FREQ;
72                 f_spi = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 96);
73                 f_pll = 0;
74                 f_pwm = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 128);
75         } else {
76                 f_cpu = f_pll;
77                 if (f_cpu > 36864000)
78                         f_bus = DIV_ROUND_UP(f_cpu, 2);
79                 else
80                         f_bus = 36864000 / 2;
81                 f_spi = DIV_ROUND_CLOSEST(f_cpu, 576);
82                 f_pwm = DIV_ROUND_CLOSEST(f_cpu, 768);
83         }
84
85         if (tmp & SYSFLG2_CKMODE) {
86                 if (readl(base + CLPS711X_SYSCON2) & SYSCON2_OSTB)
87                         f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 26);
88                 else
89                         f_tim = DIV_ROUND_CLOSEST(CLPS711X_EXT_FREQ, 24);
90         } else
91                 f_tim = DIV_ROUND_CLOSEST(f_cpu, 144);
92
93         tmp = readl(base + CLPS711X_SYSCON1);
94         /* Timer1 in free running mode.
95          * Counter will wrap around to 0xffff when it underflows
96          * and will continue to count down.
97          */
98         tmp &= ~(SYSCON1_TC1M | SYSCON1_TC1S);
99         /* Timer2 in prescale mode.
100          * Value writen is automatically re-loaded when
101          * the counter underflows.
102          */
103         tmp |= SYSCON1_TC2M | SYSCON1_TC2S;
104         writel(tmp, base + CLPS711X_SYSCON1);
105
106         clps711x_clk->clk_data.hws[CLPS711X_CLK_DUMMY] =
107                 clk_hw_register_fixed_rate(NULL, "dummy", NULL, 0, 0);
108         clps711x_clk->clk_data.hws[CLPS711X_CLK_CPU] =
109                 clk_hw_register_fixed_rate(NULL, "cpu", NULL, 0, f_cpu);
110         clps711x_clk->clk_data.hws[CLPS711X_CLK_BUS] =
111                 clk_hw_register_fixed_rate(NULL, "bus", NULL, 0, f_bus);
112         clps711x_clk->clk_data.hws[CLPS711X_CLK_PLL] =
113                 clk_hw_register_fixed_rate(NULL, "pll", NULL, 0, f_pll);
114         clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMERREF] =
115                 clk_hw_register_fixed_rate(NULL, "timer_ref", NULL, 0, f_tim);
116         clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER1] =
117                 clk_hw_register_divider_table(NULL, "timer1", "timer_ref", 0,
118                                            base + CLPS711X_SYSCON1, 5, 1, 0,
119                                            timer_div_table, &clps711x_clk->lock);
120         clps711x_clk->clk_data.hws[CLPS711X_CLK_TIMER2] =
121                 clk_hw_register_divider_table(NULL, "timer2", "timer_ref", 0,
122                                            base + CLPS711X_SYSCON1, 7, 1, 0,
123                                            timer_div_table, &clps711x_clk->lock);
124         clps711x_clk->clk_data.hws[CLPS711X_CLK_PWM] =
125                 clk_hw_register_fixed_rate(NULL, "pwm", NULL, 0, f_pwm);
126         clps711x_clk->clk_data.hws[CLPS711X_CLK_SPIREF] =
127                 clk_hw_register_fixed_rate(NULL, "spi_ref", NULL, 0, f_spi);
128         clps711x_clk->clk_data.hws[CLPS711X_CLK_SPI] =
129                 clk_hw_register_divider_table(NULL, "spi", "spi_ref", 0,
130                                            base + CLPS711X_SYSCON1, 16, 2, 0,
131                                            spi_div_table, &clps711x_clk->lock);
132         clps711x_clk->clk_data.hws[CLPS711X_CLK_UART] =
133                 clk_hw_register_fixed_factor(NULL, "uart", "bus", 0, 1, 10);
134         clps711x_clk->clk_data.hws[CLPS711X_CLK_TICK] =
135                 clk_hw_register_fixed_rate(NULL, "tick", NULL, 0, 64);
136         for (tmp = 0; tmp < CLPS711X_CLK_MAX; tmp++)
137                 if (IS_ERR(clps711x_clk->clk_data.hws[tmp]))
138                         pr_err("clk %i: register failed with %ld\n",
139                                tmp, PTR_ERR(clps711x_clk->clk_data.hws[tmp]));
140
141         clps711x_clk->clk_data.num = CLPS711X_CLK_MAX;
142         of_clk_add_hw_provider(np, of_clk_hw_onecell_get,
143                                &clps711x_clk->clk_data);
144 }
145 CLK_OF_DECLARE(clps711x, "cirrus,ep7209-clk", clps711x_clk_init_dt);