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
21static 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
58static 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(reg: &mux->reg, shift: 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 */
92static 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 */
106static 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, index: mux->saved_parent);
111}
112
113const 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
121static struct clk *_register_mux(struct device_node *node, 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(size: sizeof(*mux), GFP_KERNEL);
133 if (!mux)
134 return ERR_PTR(error: -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 = of_ti_clk_register(node, hw: &mux->hw, con: name);
152
153 if (IS_ERR(ptr: clk))
154 kfree(objp: 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 */
165static 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(np: node);
179 if (num_parents < 2) {
180 pr_err("mux-clock %pOFn must have parents\n", node);
181 return;
182 }
183 parent_names = kzalloc(size: (sizeof(char *) * num_parents), GFP_KERNEL);
184 if (!parent_names)
185 goto cleanup;
186
187 of_clk_parent_fill(np: node, parents: parent_names, size: num_parents);
188
189 if (ti_clk_get_reg_addr(node, index: 0, reg: &reg))
190 goto cleanup;
191
192 of_property_read_u32(np: node, propname: "ti,bit-shift", out_value: &shift);
193
194 of_property_read_u32(np: node, propname: "ti,latch-bit", out_value: &latch);
195
196 if (of_property_read_bool(np: node, propname: "ti,index-starts-at-one"))
197 clk_mux_flags |= CLK_MUX_INDEX_ONE;
198
199 if (of_property_read_bool(np: node, propname: "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(x: mask)) - 1;
208
209 name = ti_dt_clk_name(np: node);
210 clk = _register_mux(node, name, parent_names, num_parents,
211 flags, reg: &reg, shift, mask, latch, clk_mux_flags,
212 NULL);
213
214 if (!IS_ERR(ptr: clk))
215 of_clk_add_provider(np: node, clk_src_get: of_clk_src_simple_get, data: clk);
216
217cleanup:
218 kfree(objp: parent_names);
219}
220CLK_OF_DECLARE(mux_clk, "ti,mux-clock", of_mux_clk_setup);
221
222struct 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(size: sizeof(*mux), GFP_KERNEL);
231 if (!mux)
232 return ERR_PTR(error: -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(x: mux->mask)) - 1;
247
248 return &mux->hw;
249}
250
251static 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(size: sizeof(*mux), GFP_KERNEL);
258 if (!mux)
259 return;
260
261 if (ti_clk_get_reg_addr(node, index: 0, reg: &mux->reg))
262 goto cleanup;
263
264 if (!of_property_read_u32(np: node, propname: "ti,bit-shift", out_value: &val))
265 mux->shift = val;
266
267 if (of_property_read_bool(np: node, propname: "ti,index-starts-at-one"))
268 mux->flags |= CLK_MUX_INDEX_ONE;
269
270 num_parents = of_clk_get_parent_count(np: 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(x: mux->mask)) - 1;
279
280 if (!ti_clk_add_component(node, hw: &mux->hw, type: CLK_COMPONENT_TYPE_MUX))
281 return;
282
283cleanup:
284 kfree(objp: mux);
285}
286CLK_OF_DECLARE(ti_composite_mux_clk_setup, "ti,composite-mux-clock",
287 of_ti_composite_mux_clk_setup);
288

source code of linux/drivers/clk/ti/mux.c