1 // SPDX-License-Identifier: GPL-2.0-only
3 * mmp factor clock operation source file
5 * Copyright (C) 2012 Marvell
6 * Chao Xie <xiechao.mail@gmail.com>
9 #include <linux/clk-provider.h>
10 #include <linux/slab.h>
12 #include <linux/err.h>
18 * Fout from synthesizer can be given from two equations:
19 * numerator/denominator = Fin / (Fout * factor)
22 #define to_clk_factor(hw) container_of(hw, struct mmp_clk_factor, hw)
24 static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate,
27 struct mmp_clk_factor *factor = to_clk_factor(hw);
28 u64 rate = 0, prev_rate;
31 for (i = 0; i < factor->ftbl_cnt; i++) {
34 rate *= factor->ftbl[i].den;
35 do_div(rate, factor->ftbl[i].num * factor->masks->factor);
40 if ((i == 0) || (i == factor->ftbl_cnt)) {
43 if ((drate - prev_rate) > (rate - drate))
50 static unsigned long clk_factor_recalc_rate(struct clk_hw *hw,
51 unsigned long parent_rate)
53 struct mmp_clk_factor *factor = to_clk_factor(hw);
54 struct mmp_clk_factor_masks *masks = factor->masks;
55 unsigned int val, num, den;
58 val = readl_relaxed(factor->base);
60 /* calculate numerator */
61 num = (val >> masks->num_shift) & masks->num_mask;
63 /* calculate denominator */
64 den = (val >> masks->den_shift) & masks->den_mask;
71 do_div(rate, num * factor->masks->factor);
76 /* Configures new clock rate*/
77 static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate,
80 struct mmp_clk_factor *factor = to_clk_factor(hw);
81 struct mmp_clk_factor_masks *masks = factor->masks;
84 unsigned long flags = 0;
87 for (i = 0; i < factor->ftbl_cnt; i++) {
89 rate *= factor->ftbl[i].den;
90 do_div(rate, factor->ftbl[i].num * factor->masks->factor);
99 spin_lock_irqsave(factor->lock, flags);
101 val = readl_relaxed(factor->base);
103 val &= ~(masks->num_mask << masks->num_shift);
104 val |= (factor->ftbl[i].num & masks->num_mask) << masks->num_shift;
106 val &= ~(masks->den_mask << masks->den_shift);
107 val |= (factor->ftbl[i].den & masks->den_mask) << masks->den_shift;
109 writel_relaxed(val, factor->base);
112 spin_unlock_irqrestore(factor->lock, flags);
117 static int clk_factor_init(struct clk_hw *hw)
119 struct mmp_clk_factor *factor = to_clk_factor(hw);
120 struct mmp_clk_factor_masks *masks = factor->masks;
123 unsigned long flags = 0;
126 spin_lock_irqsave(factor->lock, flags);
128 val = readl(factor->base);
130 /* calculate numerator */
131 num = (val >> masks->num_shift) & masks->num_mask;
133 /* calculate denominator */
134 den = (val >> masks->den_shift) & masks->den_mask;
136 for (i = 0; i < factor->ftbl_cnt; i++)
137 if (den == factor->ftbl[i].den && num == factor->ftbl[i].num)
140 if (i >= factor->ftbl_cnt) {
141 val &= ~(masks->num_mask << masks->num_shift);
142 val |= (factor->ftbl[0].num & masks->num_mask) <<
145 val &= ~(masks->den_mask << masks->den_shift);
146 val |= (factor->ftbl[0].den & masks->den_mask) <<
150 if (!(val & masks->enable_mask) || i >= factor->ftbl_cnt) {
151 val |= masks->enable_mask;
152 writel(val, factor->base);
156 spin_unlock_irqrestore(factor->lock, flags);
161 static const struct clk_ops clk_factor_ops = {
162 .recalc_rate = clk_factor_recalc_rate,
163 .round_rate = clk_factor_round_rate,
164 .set_rate = clk_factor_set_rate,
165 .init = clk_factor_init,
168 struct clk *mmp_clk_register_factor(const char *name, const char *parent_name,
169 unsigned long flags, void __iomem *base,
170 struct mmp_clk_factor_masks *masks,
171 struct mmp_clk_factor_tbl *ftbl,
172 unsigned int ftbl_cnt, spinlock_t *lock)
174 struct mmp_clk_factor *factor;
175 struct clk_init_data init;
179 pr_err("%s: must pass a clk_factor_mask\n", __func__);
180 return ERR_PTR(-EINVAL);
183 factor = kzalloc(sizeof(*factor), GFP_KERNEL);
185 return ERR_PTR(-ENOMEM);
187 /* struct clk_aux assignments */
189 factor->masks = masks;
191 factor->ftbl_cnt = ftbl_cnt;
192 factor->hw.init = &init;
196 init.ops = &clk_factor_ops;
198 init.parent_names = &parent_name;
199 init.num_parents = 1;
201 clk = clk_register(NULL, &factor->hw);
202 if (IS_ERR_OR_NULL(clk))