1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * TI Multiplexer Clock
4 *
5 * Copyright (C) 2013 Texas Instruments, Inc.
6 *
7 * Tero Kristo <t-kristo@ti.com>
8 */
9
10 #include <linux/clk-provider.h>
11 #include <linux/slab.h>
12 #include <linux/err.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/clk/ti.h>
16 #include "clock.h"
17
18 #undef pr_fmt
19 #define pr_fmt(fmt) "%s: " fmt, __func__
20
ti_clk_mux_get_parent(struct clk_hw * hw)21 static u8 ti_clk_mux_get_parent(struct clk_hw *hw)
22 {
23 struct clk_omap_mux *mux = to_clk_omap_mux(hw);
24 int num_parents = clk_hw_get_num_parents(hw);
25 u32 val;
26
27 /*
28 * FIXME need a mux-specific flag to determine if val is bitwise or
29 * numeric. e.g. sys_clkin_ck's clksel field is 3 bits wide, but ranges
30 * from 0x1 to 0x7 (index starts at one)
31 * OTOH, pmd_trace_clk_mux_ck uses a separate bit for each clock, so
32 * val = 0x4 really means "bit 2, index starts at bit 0"
33 */
34 val = ti_clk_ll_ops->clk_readl(&mux->reg) >> mux->shift;
35 val &= mux->mask;
36
37 if (mux->table) {
38 int i;
39
40 for (i = 0; i < num_parents; i++)
41 if (mux->table[i] == val)
42 return i;
43 return -EINVAL;
44 }
45
46 if (val && (mux->flags & CLK_MUX_INDEX_BIT))
47 val = ffs(val) - 1;
48
49 if (val && (mux->flags & CLK_MUX_INDEX_ONE))
50 val--;
51
52 if (val >= num_parents)
53 return -EINVAL;
54
55 return val;
56 }
57
ti_clk_mux_set_parent(struct clk_hw * hw,u8 index)58 static int ti_clk_mux_set_parent(struct clk_hw *hw, u8 index)
59 {
60 struct clk_omap_mux *mux = to_clk_omap_mux(hw);
61 u32 val;
62
63 if (mux->table) {
64 index = mux->table[index];
65 } else {
66 if (mux->flags & CLK_MUX_INDEX_BIT)
67 index = (1 << ffs(index));
68
69 if (mux->flags & CLK_MUX_INDEX_ONE)
70 index++;
71 }
72
73 if (mux->flags & CLK_MUX_HIWORD_MASK) {
74 val = mux->mask << (mux->shift + 16);
75 } else {
76 val = ti_clk_ll_ops->clk_readl(&mux->reg);
77 val &= ~(mux->mask << mux->shift);
78 }
79 val |= index << mux->shift;
80 ti_clk_ll_ops->clk_writel(val, &mux->reg);
81 ti_clk_latch(&mux->reg, mux->latch);
82
83 return 0;
84 }
85
86 /**
87 * clk_mux_save_context - Save the parent selcted in the mux
88 * @hw: pointer struct clk_hw
89 *
90 * Save the parent mux value.
91 */
clk_mux_save_context(struct clk_hw * hw)92 static int clk_mux_save_context(struct clk_hw *hw)
93 {
94 struct clk_omap_mux *mux = to_clk_omap_mux(hw);
95
96 mux->saved_parent = ti_clk_mux_get_parent(hw);
97 return 0;
98 }
99
100 /**
101 * clk_mux_restore_context - Restore the parent in the mux
102 * @hw: pointer struct clk_hw
103 *
104 * Restore the saved parent mux value.
105 */
clk_mux_restore_context(struct clk_hw * hw)106 static void clk_mux_restore_context(struct clk_hw *hw)
107 {
108 struct clk_omap_mux *mux = to_clk_omap_mux(hw);
109
110 ti_clk_mux_set_parent(hw, mux->saved_parent);
111 }
112
113 const struct clk_ops ti_clk_mux_ops = {
114 .get_parent = ti_clk_mux_get_parent,
115 .set_parent = ti_clk_mux_set_parent,
116 .determine_rate = __clk_mux_determine_rate,
117 .save_context = clk_mux_save_context,
118 .restore_context = clk_mux_restore_context,
119 };
120
_register_mux(struct device * dev,const char * name,const char * const * parent_names,u8 num_parents,unsigned long flags,struct clk_omap_reg * reg,u8 shift,u32 mask,s8 latch,u8 clk_mux_flags,u32 * table)121 static struct clk *_register_mux(struct device *dev, const char *name,
122 const char * const *parent_names,
123 u8 num_parents, unsigned long flags,
124 struct clk_omap_reg *reg, u8 shift, u32 mask,
125 s8 latch, u8 clk_mux_flags, u32 *table)
126 {
127 struct clk_omap_mux *mux;
128 struct clk *clk;
129 struct clk_init_data init;
130
131 /* allocate the mux */
132 mux = kzalloc(sizeof(*mux), GFP_KERNEL);
133 if (!mux)
134 return ERR_PTR(-ENOMEM);
135
136 init.name = name;
137 init.ops = &ti_clk_mux_ops;
138 init.flags = flags;
139 init.parent_names = parent_names;
140 init.num_parents = num_parents;
141
142 /* struct clk_mux assignments */
143 memcpy(&mux->reg, reg, sizeof(*reg));
144 mux->shift = shift;
145 mux->mask = mask;
146 mux->latch = latch;
147 mux->flags = clk_mux_flags;
148 mux->table = table;
149 mux->hw.init = &init;
150
151 clk = ti_clk_register(dev, &mux->hw, name);
152
153 if (IS_ERR(clk))
154 kfree(mux);
155
156 return clk;
157 }
158
159 /**
160 * of_mux_clk_setup - Setup function for simple mux rate clock
161 * @node: DT node for the clock
162 *
163 * Sets up a basic clock multiplexer.
164 */
of_mux_clk_setup(struct device_node * node)165 static void of_mux_clk_setup(struct device_node *node)
166 {
167 struct clk *clk;
168 struct clk_omap_reg reg;
169 unsigned int num_parents;
170 const char **parent_names;
171 const char *name;
172 u8 clk_mux_flags = 0;
173 u32 mask = 0;
174 u32 shift = 0;
175 s32 latch = -EINVAL;
176 u32 flags = CLK_SET_RATE_NO_REPARENT;
177
178 num_parents = of_clk_get_parent_count(node);
179 if (num_parents < 2) {
180 pr_err("mux-clock %pOFn must have parents\n", node);
181 return;
182 }
183 parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
184 if (!parent_names)
185 goto cleanup;
186
187 of_clk_parent_fill(node, parent_names, num_parents);
188
189 if (ti_clk_get_reg_addr(node, 0, ®))
190 goto cleanup;
191
192 of_property_read_u32(node, "ti,bit-shift", &shift);
193
194 of_property_read_u32(node, "ti,latch-bit", &latch);
195
196 if (of_property_read_bool(node, "ti,index-starts-at-one"))
197 clk_mux_flags |= CLK_MUX_INDEX_ONE;
198
199 if (of_property_read_bool(node, "ti,set-rate-parent"))
200 flags |= CLK_SET_RATE_PARENT;
201
202 /* Generate bit-mask based on parent info */
203 mask = num_parents;
204 if (!(clk_mux_flags & CLK_MUX_INDEX_ONE))
205 mask--;
206
207 mask = (1 << fls(mask)) - 1;
208
209 name = ti_dt_clk_name(node);
210 clk = _register_mux(NULL, name, parent_names, num_parents,
211 flags, ®, shift, mask, latch, clk_mux_flags,
212 NULL);
213
214 if (!IS_ERR(clk))
215 of_clk_add_provider(node, of_clk_src_simple_get, clk);
216
217 cleanup:
218 kfree(parent_names);
219 }
220 CLK_OF_DECLARE(mux_clk, "ti,mux-clock", of_mux_clk_setup);
221
ti_clk_build_component_mux(struct ti_clk_mux * setup)222 struct clk_hw *ti_clk_build_component_mux(struct ti_clk_mux *setup)
223 {
224 struct clk_omap_mux *mux;
225 int num_parents;
226
227 if (!setup)
228 return NULL;
229
230 mux = kzalloc(sizeof(*mux), GFP_KERNEL);
231 if (!mux)
232 return ERR_PTR(-ENOMEM);
233
234 mux->shift = setup->bit_shift;
235 mux->latch = -EINVAL;
236
237 mux->reg.index = setup->module;
238 mux->reg.offset = setup->reg;
239
240 if (setup->flags & CLKF_INDEX_STARTS_AT_ONE)
241 mux->flags |= CLK_MUX_INDEX_ONE;
242
243 num_parents = setup->num_parents;
244
245 mux->mask = num_parents - 1;
246 mux->mask = (1 << fls(mux->mask)) - 1;
247
248 return &mux->hw;
249 }
250
of_ti_composite_mux_clk_setup(struct device_node * node)251 static void __init of_ti_composite_mux_clk_setup(struct device_node *node)
252 {
253 struct clk_omap_mux *mux;
254 unsigned int num_parents;
255 u32 val;
256
257 mux = kzalloc(sizeof(*mux), GFP_KERNEL);
258 if (!mux)
259 return;
260
261 if (ti_clk_get_reg_addr(node, 0, &mux->reg))
262 goto cleanup;
263
264 if (!of_property_read_u32(node, "ti,bit-shift", &val))
265 mux->shift = val;
266
267 if (of_property_read_bool(node, "ti,index-starts-at-one"))
268 mux->flags |= CLK_MUX_INDEX_ONE;
269
270 num_parents = of_clk_get_parent_count(node);
271
272 if (num_parents < 2) {
273 pr_err("%pOFn must have parents\n", node);
274 goto cleanup;
275 }
276
277 mux->mask = num_parents - 1;
278 mux->mask = (1 << fls(mux->mask)) - 1;
279
280 if (!ti_clk_add_component(node, &mux->hw, CLK_COMPONENT_TYPE_MUX))
281 return;
282
283 cleanup:
284 kfree(mux);
285 }
286 CLK_OF_DECLARE(ti_composite_mux_clk_setup, "ti,composite-mux-clock",
287 of_ti_composite_mux_clk_setup);
288