xref: /openbmc/linux/arch/arm/mach-sa1100/clock.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/arch/arm/mach-sa1100/clock.c
4  */
5 #include <linux/kernel.h>
6 #include <linux/errno.h>
7 #include <linux/err.h>
8 #include <linux/clk.h>
9 #include <linux/clkdev.h>
10 #include <linux/clk-provider.h>
11 #include <linux/io.h>
12 #include <linux/spinlock.h>
13 
14 #include <mach/hardware.h>
15 #include <mach/generic.h>
16 
17 static const char * const clk_tucr_parents[] = {
18 	"clk32768", "clk3686400",
19 };
20 
21 static DEFINE_SPINLOCK(tucr_lock);
22 
23 static int clk_gpio27_enable(struct clk_hw *hw)
24 {
25 	unsigned long flags;
26 
27 	/*
28 	 * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
29 	 * (SA-1110 Developer's Manual, section 9.1.2.1)
30 	 */
31 	local_irq_save(flags);
32 	GAFR |= GPIO_32_768kHz;
33 	GPDR |= GPIO_32_768kHz;
34 	local_irq_restore(flags);
35 
36 	return 0;
37 }
38 
39 static void clk_gpio27_disable(struct clk_hw *hw)
40 {
41 	unsigned long flags;
42 
43 	local_irq_save(flags);
44 	GPDR &= ~GPIO_32_768kHz;
45 	GAFR &= ~GPIO_32_768kHz;
46 	local_irq_restore(flags);
47 }
48 
49 static const struct clk_ops clk_gpio27_ops = {
50 	.enable = clk_gpio27_enable,
51 	.disable = clk_gpio27_disable,
52 };
53 
54 static const char * const clk_gpio27_parents[] = {
55 	"tucr-mux",
56 };
57 
58 static const struct clk_init_data clk_gpio27_init_data __initconst = {
59 	.name = "gpio27",
60 	.ops = &clk_gpio27_ops,
61 	.parent_names = clk_gpio27_parents,
62 	.num_parents = ARRAY_SIZE(clk_gpio27_parents),
63 };
64 
65 /*
66  * Derived from the table 8-1 in the SA1110 manual, the MPLL appears to
67  * multiply its input rate by 4 x (4 + PPCR).  This calculation gives
68  * the exact rate.  The figures given in the table are the rates rounded
69  * to 100kHz.  Stick with sa11x0_getspeed() for the time being.
70  */
71 static unsigned long clk_mpll_recalc_rate(struct clk_hw *hw,
72 	unsigned long prate)
73 {
74 	return sa11x0_getspeed(0) * 1000;
75 }
76 
77 static const struct clk_ops clk_mpll_ops = {
78 	.recalc_rate = clk_mpll_recalc_rate,
79 };
80 
81 static const char * const clk_mpll_parents[] = {
82 	"clk3686400",
83 };
84 
85 static const struct clk_init_data clk_mpll_init_data __initconst = {
86 	.name = "mpll",
87 	.ops = &clk_mpll_ops,
88 	.parent_names = clk_mpll_parents,
89 	.num_parents = ARRAY_SIZE(clk_mpll_parents),
90 	.flags = CLK_GET_RATE_NOCACHE | CLK_IS_CRITICAL,
91 };
92 
93 int __init sa11xx_clk_init(void)
94 {
95 	struct clk_hw *hw;
96 	int ret;
97 
98 	hw = clk_hw_register_fixed_rate(NULL, "clk32768", NULL, 0, 32768);
99 	if (IS_ERR(hw))
100 		return PTR_ERR(hw);
101 
102 	clk_hw_register_clkdev(hw, NULL, "sa1100-rtc");
103 
104 	hw = clk_hw_register_fixed_rate(NULL, "clk3686400", NULL, 0, 3686400);
105 	if (IS_ERR(hw))
106 		return PTR_ERR(hw);
107 
108 	clk_hw_register_clkdev(hw, "OSTIMER0", NULL);
109 
110 	hw = kzalloc(sizeof(*hw), GFP_KERNEL);
111 	if (!hw)
112 		return -ENOMEM;
113 	hw->init = &clk_mpll_init_data;
114 	ret = clk_hw_register(NULL, hw);
115 	if (ret) {
116 		kfree(hw);
117 		return ret;
118 	}
119 
120 	clk_hw_register_clkdev(hw, NULL, "sa11x0-fb");
121 	clk_hw_register_clkdev(hw, NULL, "sa11x0-pcmcia");
122 	clk_hw_register_clkdev(hw, NULL, "sa11x0-pcmcia.0");
123 	clk_hw_register_clkdev(hw, NULL, "sa11x0-pcmcia.1");
124 	clk_hw_register_clkdev(hw, NULL, "1800");
125 
126 	hw = clk_hw_register_mux(NULL, "tucr-mux", clk_tucr_parents,
127 				 ARRAY_SIZE(clk_tucr_parents), 0,
128 				 (void __iomem *)&TUCR, FShft(TUCR_TSEL),
129 				 FAlnMsk(TUCR_TSEL), 0, &tucr_lock);
130 	clk_set_rate(hw->clk, 3686400);
131 
132 	hw = kzalloc(sizeof(*hw), GFP_KERNEL);
133 	if (!hw)
134 		return -ENOMEM;
135 	hw->init = &clk_gpio27_init_data;
136 	ret = clk_hw_register(NULL, hw);
137 	if (ret) {
138 		kfree(hw);
139 		return ret;
140 	}
141 
142 	clk_hw_register_clkdev(hw, NULL, "sa1111.0");
143 
144 	return 0;
145 }
146