xref: /openbmc/linux/drivers/clk/tegra/clk-pll-out.c (revision fa622282)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/io.h>
8 #include <linux/err.h>
9 #include <linux/delay.h>
10 #include <linux/slab.h>
11 #include <linux/clk-provider.h>
12 
13 #include "clk.h"
14 
15 #define pll_out_enb(p) (BIT(p->enb_bit_idx))
16 #define pll_out_rst(p) (BIT(p->rst_bit_idx))
17 
clk_pll_out_is_enabled(struct clk_hw * hw)18 static int clk_pll_out_is_enabled(struct clk_hw *hw)
19 {
20 	struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
21 	u32 val = readl_relaxed(pll_out->reg);
22 	int state;
23 
24 	state = (val & pll_out_enb(pll_out)) ? 1 : 0;
25 	if (!(val & (pll_out_rst(pll_out))))
26 		state = 0;
27 	return state;
28 }
29 
clk_pll_out_enable(struct clk_hw * hw)30 static int clk_pll_out_enable(struct clk_hw *hw)
31 {
32 	struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
33 	unsigned long flags = 0;
34 	u32 val;
35 
36 	if (pll_out->lock)
37 		spin_lock_irqsave(pll_out->lock, flags);
38 
39 	val = readl_relaxed(pll_out->reg);
40 
41 	val |= (pll_out_enb(pll_out) | pll_out_rst(pll_out));
42 
43 	writel_relaxed(val, pll_out->reg);
44 	udelay(2);
45 
46 	if (pll_out->lock)
47 		spin_unlock_irqrestore(pll_out->lock, flags);
48 
49 	return 0;
50 }
51 
clk_pll_out_disable(struct clk_hw * hw)52 static void clk_pll_out_disable(struct clk_hw *hw)
53 {
54 	struct tegra_clk_pll_out *pll_out = to_clk_pll_out(hw);
55 	unsigned long flags = 0;
56 	u32 val;
57 
58 	if (pll_out->lock)
59 		spin_lock_irqsave(pll_out->lock, flags);
60 
61 	val = readl_relaxed(pll_out->reg);
62 
63 	val &= ~(pll_out_enb(pll_out) | pll_out_rst(pll_out));
64 
65 	writel_relaxed(val, pll_out->reg);
66 	udelay(2);
67 
68 	if (pll_out->lock)
69 		spin_unlock_irqrestore(pll_out->lock, flags);
70 }
71 
tegra_clk_pll_out_restore_context(struct clk_hw * hw)72 static void tegra_clk_pll_out_restore_context(struct clk_hw *hw)
73 {
74 	if (!__clk_get_enable_count(hw->clk))
75 		clk_pll_out_disable(hw);
76 	else
77 		clk_pll_out_enable(hw);
78 }
79 
80 const struct clk_ops tegra_clk_pll_out_ops = {
81 	.is_enabled = clk_pll_out_is_enabled,
82 	.enable = clk_pll_out_enable,
83 	.disable = clk_pll_out_disable,
84 	.restore_context = tegra_clk_pll_out_restore_context,
85 };
86 
tegra_clk_register_pll_out(const char * name,const char * parent_name,void __iomem * reg,u8 enb_bit_idx,u8 rst_bit_idx,unsigned long flags,u8 pll_out_flags,spinlock_t * lock)87 struct clk *tegra_clk_register_pll_out(const char *name,
88 		const char *parent_name, void __iomem *reg, u8 enb_bit_idx,
89 		u8 rst_bit_idx, unsigned long flags, u8 pll_out_flags,
90 		spinlock_t *lock)
91 {
92 	struct tegra_clk_pll_out *pll_out;
93 	struct clk *clk;
94 	struct clk_init_data init;
95 
96 	pll_out = kzalloc(sizeof(*pll_out), GFP_KERNEL);
97 	if (!pll_out)
98 		return ERR_PTR(-ENOMEM);
99 
100 	init.name = name;
101 	init.ops = &tegra_clk_pll_out_ops;
102 	init.parent_names = (parent_name ? &parent_name : NULL);
103 	init.num_parents = (parent_name ? 1 : 0);
104 	init.flags = flags;
105 
106 	pll_out->reg = reg;
107 	pll_out->enb_bit_idx = enb_bit_idx;
108 	pll_out->rst_bit_idx = rst_bit_idx;
109 	pll_out->flags = pll_out_flags;
110 	pll_out->lock = lock;
111 
112 	/* Data in .init is copied by clk_register(), so stack variable OK */
113 	pll_out->hw.init = &init;
114 
115 	clk = clk_register(NULL, &pll_out->hw);
116 	if (IS_ERR(clk))
117 		kfree(pll_out);
118 
119 	return clk;
120 }
121