1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2016 Maxime Ripard
4 * Maxime Ripard <maxime.ripard@free-electrons.com>
5 */
6
7#include <linux/clk-provider.h>
8#include <linux/io.h>
9
10#include "ccu_gate.h"
11#include "ccu_nkm.h"
12
13struct _ccu_nkm {
14	unsigned long	n, min_n, max_n;
15	unsigned long	k, min_k, max_k;
16	unsigned long	m, min_m, max_m;
17};
18
19static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common,
20						       struct clk_hw *parent_hw,
21						       unsigned long *parent, unsigned long rate,
22						       struct _ccu_nkm *nkm)
23{
24	unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent = *parent;
25	unsigned long best_n = 0, best_k = 0, best_m = 0;
26	unsigned long _n, _k, _m;
27
28	for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
29		for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
30			for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
31				unsigned long tmp_rate;
32
33				tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
34
35				tmp_rate = tmp_parent * _n * _k / _m;
36
37				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
38				    (tmp_parent == *parent && tmp_rate == best_rate)) {
39					best_rate = tmp_rate;
40					best_parent_rate = tmp_parent;
41					best_n = _n;
42					best_k = _k;
43					best_m = _m;
44				}
45			}
46		}
47	}
48
49	nkm->n = best_n;
50	nkm->k = best_k;
51	nkm->m = best_m;
52
53	*parent = best_parent_rate;
54
55	return best_rate;
56}
57
58static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
59				       struct _ccu_nkm *nkm, struct ccu_common *common)
60{
61	unsigned long best_rate = 0;
62	unsigned long best_n = 0, best_k = 0, best_m = 0;
63	unsigned long _n, _k, _m;
64
65	for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
66		for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
67			for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
68				unsigned long tmp_rate;
69
70				tmp_rate = parent * _n * _k / _m;
71
72				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
73					best_rate = tmp_rate;
74					best_n = _n;
75					best_k = _k;
76					best_m = _m;
77				}
78			}
79		}
80	}
81
82	nkm->n = best_n;
83	nkm->k = best_k;
84	nkm->m = best_m;
85
86	return best_rate;
87}
88
89static void ccu_nkm_disable(struct clk_hw *hw)
90{
91	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
92
93	return ccu_gate_helper_disable(&nkm->common, nkm->enable);
94}
95
96static int ccu_nkm_enable(struct clk_hw *hw)
97{
98	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
99
100	return ccu_gate_helper_enable(&nkm->common, nkm->enable);
101}
102
103static int ccu_nkm_is_enabled(struct clk_hw *hw)
104{
105	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
106
107	return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable);
108}
109
110static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
111					unsigned long parent_rate)
112{
113	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
114	unsigned long n, m, k, rate;
115	u32 reg;
116
117	reg = readl(nkm->common.base + nkm->common.reg);
118
119	n = reg >> nkm->n.shift;
120	n &= (1 << nkm->n.width) - 1;
121	n += nkm->n.offset;
122	if (!n)
123		n++;
124
125	k = reg >> nkm->k.shift;
126	k &= (1 << nkm->k.width) - 1;
127	k += nkm->k.offset;
128	if (!k)
129		k++;
130
131	m = reg >> nkm->m.shift;
132	m &= (1 << nkm->m.width) - 1;
133	m += nkm->m.offset;
134	if (!m)
135		m++;
136
137	rate = parent_rate * n  * k / m;
138
139	if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
140		rate /= nkm->fixed_post_div;
141
142	return rate;
143}
144
145static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
146					struct clk_hw *parent_hw,
147					unsigned long *parent_rate,
148					unsigned long rate,
149					void *data)
150{
151	struct ccu_nkm *nkm = data;
152	struct _ccu_nkm _nkm;
153
154	_nkm.min_n = nkm->n.min ?: 1;
155	_nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
156	_nkm.min_k = nkm->k.min ?: 1;
157	_nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
158	_nkm.min_m = 1;
159	_nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
160
161	if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
162		rate *= nkm->fixed_post_div;
163
164	if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
165		rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm, &nkm->common);
166	else
167		rate = ccu_nkm_find_best_with_parent_adj(&nkm->common, parent_hw, parent_rate, rate,
168							 &_nkm);
169
170	if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
171		rate /= nkm->fixed_post_div;
172
173	return rate;
174}
175
176static int ccu_nkm_determine_rate(struct clk_hw *hw,
177				  struct clk_rate_request *req)
178{
179	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
180
181	return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux,
182					     req, ccu_nkm_round_rate, nkm);
183}
184
185static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
186			   unsigned long parent_rate)
187{
188	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
189	struct _ccu_nkm _nkm;
190	unsigned long flags;
191	u32 reg;
192
193	if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
194		rate *= nkm->fixed_post_div;
195
196	_nkm.min_n = nkm->n.min ?: 1;
197	_nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
198	_nkm.min_k = nkm->k.min ?: 1;
199	_nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
200	_nkm.min_m = 1;
201	_nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
202
203	ccu_nkm_find_best(parent_rate, rate, &_nkm, &nkm->common);
204
205	spin_lock_irqsave(nkm->common.lock, flags);
206
207	reg = readl(nkm->common.base + nkm->common.reg);
208	reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift);
209	reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
210	reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
211
212	reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift;
213	reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift;
214	reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift;
215	writel(reg, nkm->common.base + nkm->common.reg);
216
217	spin_unlock_irqrestore(nkm->common.lock, flags);
218
219	ccu_helper_wait_for_lock(&nkm->common, nkm->lock);
220
221	return 0;
222}
223
224static u8 ccu_nkm_get_parent(struct clk_hw *hw)
225{
226	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
227
228	return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux);
229}
230
231static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index)
232{
233	struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
234
235	return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index);
236}
237
238const struct clk_ops ccu_nkm_ops = {
239	.disable	= ccu_nkm_disable,
240	.enable		= ccu_nkm_enable,
241	.is_enabled	= ccu_nkm_is_enabled,
242
243	.get_parent	= ccu_nkm_get_parent,
244	.set_parent	= ccu_nkm_set_parent,
245
246	.determine_rate	= ccu_nkm_determine_rate,
247	.recalc_rate	= ccu_nkm_recalc_rate,
248	.set_rate	= ccu_nkm_set_rate,
249};
250EXPORT_SYMBOL_NS_GPL(ccu_nkm_ops, SUNXI_CCU);
251