1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2018 NVIDIA CORPORATION. All rights reserved.
4 *
5 * based on clk-mux.c
6 *
7 * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
8 * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
9 * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
10 *
11 */
12
13#include <linux/clk-provider.h>
14#include <linux/err.h>
15#include <linux/io.h>
16#include <linux/types.h>
17
18#include "clk.h"
19
20#define DIV_MASK GENMASK(7, 0)
21#define MUX_SHIFT 29
22#define MUX_MASK GENMASK(MUX_SHIFT + 2, MUX_SHIFT)
23#define SDMMC_MUL 2
24
25#define get_max_div(d) DIV_MASK
26#define get_div_field(val) ((val) & DIV_MASK)
27#define get_mux_field(val) (((val) & MUX_MASK) >> MUX_SHIFT)
28
29static const char * const mux_sdmmc_parents[] = {
30 "pll_p", "pll_c4_out2", "pll_c4_out0", "pll_c4_out1", "clk_m"
31};
32
33static const u8 mux_lj_idx[] = {
34 [0] = 0, [1] = 1, [2] = 2, [3] = 5, [4] = 6
35};
36
37static const u8 mux_non_lj_idx[] = {
38 [0] = 0, [1] = 3, [2] = 7, [3] = 4, [4] = 6
39};
40
41static u8 clk_sdmmc_mux_get_parent(struct clk_hw *hw)
42{
43 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
44 int num_parents, i;
45 u32 src, val;
46 const u8 *mux_idx;
47
48 num_parents = clk_hw_get_num_parents(hw);
49
50 val = readl_relaxed(sdmmc_mux->reg);
51 src = get_mux_field(val);
52 if (get_div_field(val))
53 mux_idx = mux_non_lj_idx;
54 else
55 mux_idx = mux_lj_idx;
56
57 for (i = 0; i < num_parents; i++) {
58 if (mux_idx[i] == src)
59 return i;
60 }
61
62 WARN(1, "Unknown parent selector %d\n", src);
63
64 return 0;
65}
66
67static int clk_sdmmc_mux_set_parent(struct clk_hw *hw, u8 index)
68{
69 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
70 u32 val;
71
72
73 val = readl_relaxed(sdmmc_mux->reg);
74 if (get_div_field(val))
75 index = mux_non_lj_idx[index];
76 else
77 index = mux_lj_idx[index];
78
79 val &= ~MUX_MASK;
80 val |= index << MUX_SHIFT;
81
82 writel(val, addr: sdmmc_mux->reg);
83
84 return 0;
85}
86
87static unsigned long clk_sdmmc_mux_recalc_rate(struct clk_hw *hw,
88 unsigned long parent_rate)
89{
90 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
91 u32 val;
92 int div;
93 u64 rate = parent_rate;
94
95 val = readl_relaxed(sdmmc_mux->reg);
96 div = get_div_field(val);
97
98 div += SDMMC_MUL;
99
100 rate *= SDMMC_MUL;
101 rate += div - 1;
102 do_div(rate, div);
103
104 return rate;
105}
106
107static int clk_sdmmc_mux_determine_rate(struct clk_hw *hw,
108 struct clk_rate_request *req)
109{
110 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
111 int div;
112 unsigned long output_rate = req->best_parent_rate;
113
114 req->rate = max(req->rate, req->min_rate);
115 req->rate = min(req->rate, req->max_rate);
116
117 if (!req->rate)
118 return output_rate;
119
120 div = div_frac_get(rate: req->rate, parent_rate: output_rate, width: 8, frac_width: 1, flags: sdmmc_mux->div_flags);
121 if (div < 0)
122 div = 0;
123
124 if (sdmmc_mux->div_flags & TEGRA_DIVIDER_ROUND_UP)
125 req->rate = DIV_ROUND_UP(output_rate * SDMMC_MUL,
126 div + SDMMC_MUL);
127 else
128 req->rate = output_rate * SDMMC_MUL / (div + SDMMC_MUL);
129
130 return 0;
131}
132
133static int clk_sdmmc_mux_set_rate(struct clk_hw *hw, unsigned long rate,
134 unsigned long parent_rate)
135{
136 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
137 int div;
138 unsigned long flags = 0;
139 u32 val;
140 u8 src;
141
142 div = div_frac_get(rate, parent_rate, width: 8, frac_width: 1, flags: sdmmc_mux->div_flags);
143 if (div < 0)
144 return div;
145
146 if (sdmmc_mux->lock)
147 spin_lock_irqsave(sdmmc_mux->lock, flags);
148
149 src = clk_sdmmc_mux_get_parent(hw);
150 if (div)
151 src = mux_non_lj_idx[src];
152 else
153 src = mux_lj_idx[src];
154
155 val = src << MUX_SHIFT;
156 val |= div;
157 writel(val, addr: sdmmc_mux->reg);
158 fence_udelay(2, sdmmc_mux->reg);
159
160 if (sdmmc_mux->lock)
161 spin_unlock_irqrestore(lock: sdmmc_mux->lock, flags);
162
163 return 0;
164}
165
166static int clk_sdmmc_mux_is_enabled(struct clk_hw *hw)
167{
168 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
169 const struct clk_ops *gate_ops = sdmmc_mux->gate_ops;
170 struct clk_hw *gate_hw = &sdmmc_mux->gate.hw;
171
172 __clk_hw_set_clk(dst: gate_hw, src: hw);
173
174 return gate_ops->is_enabled(gate_hw);
175}
176
177static int clk_sdmmc_mux_enable(struct clk_hw *hw)
178{
179 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
180 const struct clk_ops *gate_ops = sdmmc_mux->gate_ops;
181 struct clk_hw *gate_hw = &sdmmc_mux->gate.hw;
182
183 __clk_hw_set_clk(dst: gate_hw, src: hw);
184
185 return gate_ops->enable(gate_hw);
186}
187
188static void clk_sdmmc_mux_disable(struct clk_hw *hw)
189{
190 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
191 const struct clk_ops *gate_ops = sdmmc_mux->gate_ops;
192 struct clk_hw *gate_hw = &sdmmc_mux->gate.hw;
193
194 gate_ops->disable(gate_hw);
195}
196
197static void clk_sdmmc_mux_disable_unused(struct clk_hw *hw)
198{
199 struct tegra_sdmmc_mux *sdmmc_mux = to_clk_sdmmc_mux(hw);
200 const struct clk_ops *gate_ops = sdmmc_mux->gate_ops;
201 struct clk_hw *gate_hw = &sdmmc_mux->gate.hw;
202
203 gate_ops->disable_unused(gate_hw);
204}
205
206static void clk_sdmmc_mux_restore_context(struct clk_hw *hw)
207{
208 struct clk_hw *parent = clk_hw_get_parent(hw);
209 unsigned long parent_rate = clk_hw_get_rate(hw: parent);
210 unsigned long rate = clk_hw_get_rate(hw);
211 int parent_id;
212
213 parent_id = clk_hw_get_parent_index(hw);
214 if (WARN_ON(parent_id < 0))
215 return;
216
217 clk_sdmmc_mux_set_parent(hw, index: parent_id);
218 clk_sdmmc_mux_set_rate(hw, rate, parent_rate);
219}
220
221static const struct clk_ops tegra_clk_sdmmc_mux_ops = {
222 .get_parent = clk_sdmmc_mux_get_parent,
223 .set_parent = clk_sdmmc_mux_set_parent,
224 .determine_rate = clk_sdmmc_mux_determine_rate,
225 .recalc_rate = clk_sdmmc_mux_recalc_rate,
226 .set_rate = clk_sdmmc_mux_set_rate,
227 .is_enabled = clk_sdmmc_mux_is_enabled,
228 .enable = clk_sdmmc_mux_enable,
229 .disable = clk_sdmmc_mux_disable,
230 .disable_unused = clk_sdmmc_mux_disable_unused,
231 .restore_context = clk_sdmmc_mux_restore_context,
232};
233
234struct clk *tegra_clk_register_sdmmc_mux_div(const char *name,
235 void __iomem *clk_base, u32 offset, u32 clk_num, u8 div_flags,
236 unsigned long flags, void *lock)
237{
238 struct clk *clk;
239 struct clk_init_data init;
240 const struct tegra_clk_periph_regs *bank;
241 struct tegra_sdmmc_mux *sdmmc_mux;
242
243 init.ops = &tegra_clk_sdmmc_mux_ops;
244 init.name = name;
245 init.flags = flags;
246 init.parent_names = mux_sdmmc_parents;
247 init.num_parents = ARRAY_SIZE(mux_sdmmc_parents);
248
249 bank = get_reg_bank(clkid: clk_num);
250 if (!bank)
251 return ERR_PTR(error: -EINVAL);
252
253 sdmmc_mux = kzalloc(size: sizeof(*sdmmc_mux), GFP_KERNEL);
254 if (!sdmmc_mux)
255 return ERR_PTR(error: -ENOMEM);
256
257 /* Data in .init is copied by clk_register(), so stack variable OK */
258 sdmmc_mux->hw.init = &init;
259 sdmmc_mux->reg = clk_base + offset;
260 sdmmc_mux->lock = lock;
261 sdmmc_mux->gate.clk_base = clk_base;
262 sdmmc_mux->gate.regs = bank;
263 sdmmc_mux->gate.enable_refcnt = periph_clk_enb_refcnt;
264 sdmmc_mux->gate.clk_num = clk_num;
265 sdmmc_mux->gate.flags = TEGRA_PERIPH_ON_APB;
266 sdmmc_mux->div_flags = div_flags;
267 sdmmc_mux->gate_ops = &tegra_clk_periph_gate_ops;
268
269 clk = clk_register(NULL, hw: &sdmmc_mux->hw);
270 if (IS_ERR(ptr: clk)) {
271 kfree(objp: sdmmc_mux);
272 return clk;
273 }
274
275 sdmmc_mux->gate.hw.clk = clk;
276
277 return clk;
278}
279

source code of linux/drivers/clk/tegra/clk-sdmmc-mux.c