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/delay.h>
9 #include <linux/err.h>
10 #include <linux/slab.h>
11 #include <linux/clk-provider.h>
12
13 #include "clk.h"
14
15 #define SUPER_STATE_IDLE 0
16 #define SUPER_STATE_RUN 1
17 #define SUPER_STATE_IRQ 2
18 #define SUPER_STATE_FIQ 3
19
20 #define SUPER_STATE_SHIFT 28
21 #define SUPER_STATE_MASK ((BIT(SUPER_STATE_IDLE) | BIT(SUPER_STATE_RUN) | \
22 BIT(SUPER_STATE_IRQ) | BIT(SUPER_STATE_FIQ)) \
23 << SUPER_STATE_SHIFT)
24
25 #define SUPER_LP_DIV2_BYPASS (1 << 16)
26
27 #define super_state(s) (BIT(s) << SUPER_STATE_SHIFT)
28 #define super_state_to_src_shift(m, s) ((m->width * s))
29 #define super_state_to_src_mask(m) (((1 << m->width) - 1))
30
clk_super_get_parent(struct clk_hw * hw)31 static u8 clk_super_get_parent(struct clk_hw *hw)
32 {
33 struct tegra_clk_super_mux *mux = to_clk_super_mux(hw);
34 u32 val, state;
35 u8 source, shift;
36
37 val = readl_relaxed(mux->reg);
38
39 state = val & SUPER_STATE_MASK;
40
41 BUG_ON((state != super_state(SUPER_STATE_RUN)) &&
42 (state != super_state(SUPER_STATE_IDLE)));
43 shift = (state == super_state(SUPER_STATE_IDLE)) ?
44 super_state_to_src_shift(mux, SUPER_STATE_IDLE) :
45 super_state_to_src_shift(mux, SUPER_STATE_RUN);
46
47 source = (val >> shift) & super_state_to_src_mask(mux);
48
49 /*
50 * If LP_DIV2_BYPASS is not set and PLLX is current parent then
51 * PLLX/2 is the input source to CCLKLP.
52 */
53 if ((mux->flags & TEGRA_DIVIDER_2) && !(val & SUPER_LP_DIV2_BYPASS) &&
54 (source == mux->pllx_index))
55 source = mux->div2_index;
56
57 return source;
58 }
59
clk_super_set_parent(struct clk_hw * hw,u8 index)60 static int clk_super_set_parent(struct clk_hw *hw, u8 index)
61 {
62 struct tegra_clk_super_mux *mux = to_clk_super_mux(hw);
63 u32 val, state;
64 int err = 0;
65 u8 parent_index, shift;
66 unsigned long flags = 0;
67
68 if (mux->lock)
69 spin_lock_irqsave(mux->lock, flags);
70
71 val = readl_relaxed(mux->reg);
72 state = val & SUPER_STATE_MASK;
73 BUG_ON((state != super_state(SUPER_STATE_RUN)) &&
74 (state != super_state(SUPER_STATE_IDLE)));
75 shift = (state == super_state(SUPER_STATE_IDLE)) ?
76 super_state_to_src_shift(mux, SUPER_STATE_IDLE) :
77 super_state_to_src_shift(mux, SUPER_STATE_RUN);
78
79 /*
80 * For LP mode super-clock switch between PLLX direct
81 * and divided-by-2 outputs is allowed only when other
82 * than PLLX clock source is current parent.
83 */
84 if ((mux->flags & TEGRA_DIVIDER_2) && ((index == mux->div2_index) ||
85 (index == mux->pllx_index))) {
86 parent_index = clk_super_get_parent(hw);
87 if ((parent_index == mux->div2_index) ||
88 (parent_index == mux->pllx_index)) {
89 err = -EINVAL;
90 goto out;
91 }
92
93 val ^= SUPER_LP_DIV2_BYPASS;
94 writel_relaxed(val, mux->reg);
95 udelay(2);
96
97 if (index == mux->div2_index)
98 index = mux->pllx_index;
99 }
100 val &= ~((super_state_to_src_mask(mux)) << shift);
101 val |= (index & (super_state_to_src_mask(mux))) << shift;
102
103 writel_relaxed(val, mux->reg);
104 udelay(2);
105
106 out:
107 if (mux->lock)
108 spin_unlock_irqrestore(mux->lock, flags);
109
110 return err;
111 }
112
113 static const struct clk_ops tegra_clk_super_mux_ops = {
114 .get_parent = clk_super_get_parent,
115 .set_parent = clk_super_set_parent,
116 };
117
clk_super_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)118 static long clk_super_round_rate(struct clk_hw *hw, unsigned long rate,
119 unsigned long *parent_rate)
120 {
121 struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
122 struct clk_hw *div_hw = &super->frac_div.hw;
123
124 __clk_hw_set_clk(div_hw, hw);
125
126 return super->div_ops->round_rate(div_hw, rate, parent_rate);
127 }
128
clk_super_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)129 static unsigned long clk_super_recalc_rate(struct clk_hw *hw,
130 unsigned long parent_rate)
131 {
132 struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
133 struct clk_hw *div_hw = &super->frac_div.hw;
134
135 __clk_hw_set_clk(div_hw, hw);
136
137 return super->div_ops->recalc_rate(div_hw, parent_rate);
138 }
139
clk_super_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)140 static int clk_super_set_rate(struct clk_hw *hw, unsigned long rate,
141 unsigned long parent_rate)
142 {
143 struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
144 struct clk_hw *div_hw = &super->frac_div.hw;
145
146 __clk_hw_set_clk(div_hw, hw);
147
148 return super->div_ops->set_rate(div_hw, rate, parent_rate);
149 }
150
151 const struct clk_ops tegra_clk_super_ops = {
152 .get_parent = clk_super_get_parent,
153 .set_parent = clk_super_set_parent,
154 .set_rate = clk_super_set_rate,
155 .round_rate = clk_super_round_rate,
156 .recalc_rate = clk_super_recalc_rate,
157 };
158
tegra_clk_register_super_mux(const char * name,const char ** parent_names,u8 num_parents,unsigned long flags,void __iomem * reg,u8 clk_super_flags,u8 width,u8 pllx_index,u8 div2_index,spinlock_t * lock)159 struct clk *tegra_clk_register_super_mux(const char *name,
160 const char **parent_names, u8 num_parents,
161 unsigned long flags, void __iomem *reg, u8 clk_super_flags,
162 u8 width, u8 pllx_index, u8 div2_index, spinlock_t *lock)
163 {
164 struct tegra_clk_super_mux *super;
165 struct clk *clk;
166 struct clk_init_data init;
167
168 super = kzalloc(sizeof(*super), GFP_KERNEL);
169 if (!super)
170 return ERR_PTR(-ENOMEM);
171
172 init.name = name;
173 init.ops = &tegra_clk_super_mux_ops;
174 init.flags = flags;
175 init.parent_names = parent_names;
176 init.num_parents = num_parents;
177
178 super->reg = reg;
179 super->pllx_index = pllx_index;
180 super->div2_index = div2_index;
181 super->lock = lock;
182 super->width = width;
183 super->flags = clk_super_flags;
184
185 /* Data in .init is copied by clk_register(), so stack variable OK */
186 super->hw.init = &init;
187
188 clk = clk_register(NULL, &super->hw);
189 if (IS_ERR(clk))
190 kfree(super);
191
192 return clk;
193 }
194
tegra_clk_register_super_clk(const char * name,const char * const * parent_names,u8 num_parents,unsigned long flags,void __iomem * reg,u8 clk_super_flags,spinlock_t * lock)195 struct clk *tegra_clk_register_super_clk(const char *name,
196 const char * const *parent_names, u8 num_parents,
197 unsigned long flags, void __iomem *reg, u8 clk_super_flags,
198 spinlock_t *lock)
199 {
200 struct tegra_clk_super_mux *super;
201 struct clk *clk;
202 struct clk_init_data init;
203
204 super = kzalloc(sizeof(*super), GFP_KERNEL);
205 if (!super)
206 return ERR_PTR(-ENOMEM);
207
208 init.name = name;
209 init.ops = &tegra_clk_super_ops;
210 init.flags = flags;
211 init.parent_names = parent_names;
212 init.num_parents = num_parents;
213
214 super->reg = reg;
215 super->lock = lock;
216 super->width = 4;
217 super->flags = clk_super_flags;
218 super->frac_div.reg = reg + 4;
219 super->frac_div.shift = 16;
220 super->frac_div.width = 8;
221 super->frac_div.frac_width = 1;
222 super->frac_div.lock = lock;
223 super->div_ops = &tegra_clk_frac_div_ops;
224
225 /* Data in .init is copied by clk_register(), so stack variable OK */
226 super->hw.init = &init;
227
228 clk = clk_register(NULL, &super->hw);
229 if (IS_ERR(clk))
230 kfree(super);
231
232 return clk;
233 }
234