1 /*
2 * Copyright 2015 Chen-Yu Tsai
3 *
4 * Chen-Yu Tsai <wens@csie.org>
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 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17 #include <linux/clk-provider.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/reset-controller.h>
21 #include <linux/slab.h>
22 #include <linux/spinlock.h>
23
24 static DEFINE_SPINLOCK(ve_lock);
25
26 #define SUN4I_VE_ENABLE 31
27 #define SUN4I_VE_DIVIDER_SHIFT 16
28 #define SUN4I_VE_DIVIDER_WIDTH 3
29 #define SUN4I_VE_RESET 0
30
31 /**
32 * sunxi_ve_reset... - reset bit in ve clk registers handling
33 */
34
35 struct ve_reset_data {
36 void __iomem *reg;
37 spinlock_t *lock;
38 struct reset_controller_dev rcdev;
39 };
40
sunxi_ve_reset_assert(struct reset_controller_dev * rcdev,unsigned long id)41 static int sunxi_ve_reset_assert(struct reset_controller_dev *rcdev,
42 unsigned long id)
43 {
44 struct ve_reset_data *data = container_of(rcdev,
45 struct ve_reset_data,
46 rcdev);
47 unsigned long flags;
48 u32 reg;
49
50 spin_lock_irqsave(data->lock, flags);
51
52 reg = readl(data->reg);
53 writel(reg & ~BIT(SUN4I_VE_RESET), data->reg);
54
55 spin_unlock_irqrestore(data->lock, flags);
56
57 return 0;
58 }
59
sunxi_ve_reset_deassert(struct reset_controller_dev * rcdev,unsigned long id)60 static int sunxi_ve_reset_deassert(struct reset_controller_dev *rcdev,
61 unsigned long id)
62 {
63 struct ve_reset_data *data = container_of(rcdev,
64 struct ve_reset_data,
65 rcdev);
66 unsigned long flags;
67 u32 reg;
68
69 spin_lock_irqsave(data->lock, flags);
70
71 reg = readl(data->reg);
72 writel(reg | BIT(SUN4I_VE_RESET), data->reg);
73
74 spin_unlock_irqrestore(data->lock, flags);
75
76 return 0;
77 }
78
sunxi_ve_of_xlate(struct reset_controller_dev * rcdev,const struct of_phandle_args * reset_spec)79 static int sunxi_ve_of_xlate(struct reset_controller_dev *rcdev,
80 const struct of_phandle_args *reset_spec)
81 {
82 if (WARN_ON(reset_spec->args_count != 0))
83 return -EINVAL;
84
85 return 0;
86 }
87
88 static const struct reset_control_ops sunxi_ve_reset_ops = {
89 .assert = sunxi_ve_reset_assert,
90 .deassert = sunxi_ve_reset_deassert,
91 };
92
sun4i_ve_clk_setup(struct device_node * node)93 static void __init sun4i_ve_clk_setup(struct device_node *node)
94 {
95 struct clk *clk;
96 struct clk_divider *div;
97 struct clk_gate *gate;
98 struct ve_reset_data *reset_data;
99 const char *parent;
100 const char *clk_name = node->name;
101 void __iomem *reg;
102 int err;
103
104 reg = of_io_request_and_map(node, 0, of_node_full_name(node));
105 if (IS_ERR(reg))
106 return;
107
108 div = kzalloc(sizeof(*div), GFP_KERNEL);
109 if (!div)
110 goto err_unmap;
111
112 gate = kzalloc(sizeof(*gate), GFP_KERNEL);
113 if (!gate)
114 goto err_free_div;
115
116 of_property_read_string(node, "clock-output-names", &clk_name);
117 parent = of_clk_get_parent_name(node, 0);
118
119 gate->reg = reg;
120 gate->bit_idx = SUN4I_VE_ENABLE;
121 gate->lock = &ve_lock;
122
123 div->reg = reg;
124 div->shift = SUN4I_VE_DIVIDER_SHIFT;
125 div->width = SUN4I_VE_DIVIDER_WIDTH;
126 div->lock = &ve_lock;
127
128 clk = clk_register_composite(NULL, clk_name, &parent, 1,
129 NULL, NULL,
130 &div->hw, &clk_divider_ops,
131 &gate->hw, &clk_gate_ops,
132 CLK_SET_RATE_PARENT);
133 if (IS_ERR(clk))
134 goto err_free_gate;
135
136 err = of_clk_add_provider(node, of_clk_src_simple_get, clk);
137 if (err)
138 goto err_unregister_clk;
139
140 reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
141 if (!reset_data)
142 goto err_del_provider;
143
144 reset_data->reg = reg;
145 reset_data->lock = &ve_lock;
146 reset_data->rcdev.nr_resets = 1;
147 reset_data->rcdev.ops = &sunxi_ve_reset_ops;
148 reset_data->rcdev.of_node = node;
149 reset_data->rcdev.of_xlate = sunxi_ve_of_xlate;
150 reset_data->rcdev.of_reset_n_cells = 0;
151 err = reset_controller_register(&reset_data->rcdev);
152 if (err)
153 goto err_free_reset;
154
155 return;
156
157 err_free_reset:
158 kfree(reset_data);
159 err_del_provider:
160 of_clk_del_provider(node);
161 err_unregister_clk:
162 clk_unregister(clk);
163 err_free_gate:
164 kfree(gate);
165 err_free_div:
166 kfree(div);
167 err_unmap:
168 iounmap(reg);
169 }
170 CLK_OF_DECLARE(sun4i_ve, "allwinner,sun4i-a10-ve-clk",
171 sun4i_ve_clk_setup);
172
