1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2016 Maxime Ripard
4 * Maxime Ripard <maxime.ripard@free-electrons.com>
8 #include <linux/clk-provider.h>
9 #include <linux/delay.h>
15 #define CCU_MUX_KEY_VALUE 0x16aa0000
17 static u16 ccu_mux_get_prediv(struct ccu_common *common,
18 struct ccu_mux_internal *cm,
24 if (!((common->features & CCU_FEATURE_FIXED_PREDIV) ||
25 (common->features & CCU_FEATURE_VARIABLE_PREDIV) ||
26 (common->features & CCU_FEATURE_ALL_PREDIV)))
29 if (common->features & CCU_FEATURE_ALL_PREDIV)
30 return common->prediv;
32 reg = readl(common->base + common->reg);
33 if (parent_index < 0) {
34 parent_index = reg >> cm->shift;
35 parent_index &= (1 << cm->width) - 1;
38 if (common->features & CCU_FEATURE_FIXED_PREDIV) {
41 for (i = 0; i < cm->n_predivs; i++)
42 if (parent_index == cm->fixed_predivs[i].index)
43 prediv = cm->fixed_predivs[i].div;
46 if (common->features & CCU_FEATURE_VARIABLE_PREDIV) {
49 for (i = 0; i < cm->n_var_predivs; i++)
50 if (parent_index == cm->var_predivs[i].index) {
53 div = reg >> cm->var_predivs[i].shift;
54 div &= (1 << cm->var_predivs[i].width) - 1;
62 unsigned long ccu_mux_helper_apply_prediv(struct ccu_common *common,
63 struct ccu_mux_internal *cm,
65 unsigned long parent_rate)
67 return parent_rate / ccu_mux_get_prediv(common, cm, parent_index);
69 EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_apply_prediv, SUNXI_CCU);
71 static unsigned long ccu_mux_helper_unapply_prediv(struct ccu_common *common,
72 struct ccu_mux_internal *cm,
74 unsigned long parent_rate)
76 return parent_rate * ccu_mux_get_prediv(common, cm, parent_index);
79 int ccu_mux_helper_determine_rate(struct ccu_common *common,
80 struct ccu_mux_internal *cm,
81 struct clk_rate_request *req,
82 unsigned long (*round)(struct ccu_mux_internal *,
89 unsigned long best_parent_rate = 0, best_rate = 0;
90 struct clk_hw *best_parent, *hw = &common->hw;
93 if (clk_hw_get_flags(hw) & CLK_SET_RATE_NO_REPARENT) {
94 unsigned long adj_parent_rate;
96 best_parent = clk_hw_get_parent(hw);
97 best_parent_rate = clk_hw_get_rate(best_parent);
98 adj_parent_rate = ccu_mux_helper_apply_prediv(common, cm, -1,
101 best_rate = round(cm, best_parent, &adj_parent_rate,
105 * adj_parent_rate might have been modified by our clock.
106 * Unapply the pre-divider if there's one, and give
107 * the actual frequency the parent needs to run at.
109 best_parent_rate = ccu_mux_helper_unapply_prediv(common, cm, -1,
115 for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
116 unsigned long tmp_rate, parent_rate;
117 struct clk_hw *parent;
119 parent = clk_hw_get_parent_by_index(hw, i);
123 parent_rate = ccu_mux_helper_apply_prediv(common, cm, i,
124 clk_hw_get_rate(parent));
126 tmp_rate = round(cm, parent, &parent_rate, req->rate, data);
129 * parent_rate might have been modified by our clock.
130 * Unapply the pre-divider if there's one, and give
131 * the actual frequency the parent needs to run at.
133 parent_rate = ccu_mux_helper_unapply_prediv(common, cm, i,
135 if (tmp_rate == req->rate) {
136 best_parent = parent;
137 best_parent_rate = parent_rate;
138 best_rate = tmp_rate;
142 if (ccu_is_better_rate(common, req->rate, tmp_rate, best_rate)) {
143 best_rate = tmp_rate;
144 best_parent_rate = parent_rate;
145 best_parent = parent;
153 req->best_parent_hw = best_parent;
154 req->best_parent_rate = best_parent_rate;
155 req->rate = best_rate;
158 EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_determine_rate, SUNXI_CCU);
160 u8 ccu_mux_helper_get_parent(struct ccu_common *common,
161 struct ccu_mux_internal *cm)
166 reg = readl(common->base + common->reg);
167 parent = reg >> cm->shift;
168 parent &= (1 << cm->width) - 1;
171 int num_parents = clk_hw_get_num_parents(&common->hw);
174 for (i = 0; i < num_parents; i++)
175 if (cm->table[i] == parent)
181 EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_get_parent, SUNXI_CCU);
183 int ccu_mux_helper_set_parent(struct ccu_common *common,
184 struct ccu_mux_internal *cm,
191 index = cm->table[index];
193 spin_lock_irqsave(common->lock, flags);
195 reg = readl(common->base + common->reg);
197 /* The key field always reads as zero. */
198 if (common->features & CCU_FEATURE_KEY_FIELD)
199 reg |= CCU_MUX_KEY_VALUE;
201 reg &= ~GENMASK(cm->width + cm->shift - 1, cm->shift);
202 writel(reg | (index << cm->shift), common->base + common->reg);
204 spin_unlock_irqrestore(common->lock, flags);
208 EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_set_parent, SUNXI_CCU);
210 static void ccu_mux_disable(struct clk_hw *hw)
212 struct ccu_mux *cm = hw_to_ccu_mux(hw);
214 return ccu_gate_helper_disable(&cm->common, cm->enable);
217 static int ccu_mux_enable(struct clk_hw *hw)
219 struct ccu_mux *cm = hw_to_ccu_mux(hw);
221 return ccu_gate_helper_enable(&cm->common, cm->enable);
224 static int ccu_mux_is_enabled(struct clk_hw *hw)
226 struct ccu_mux *cm = hw_to_ccu_mux(hw);
228 return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
231 static u8 ccu_mux_get_parent(struct clk_hw *hw)
233 struct ccu_mux *cm = hw_to_ccu_mux(hw);
235 return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
238 static int ccu_mux_set_parent(struct clk_hw *hw, u8 index)
240 struct ccu_mux *cm = hw_to_ccu_mux(hw);
242 return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
245 static int ccu_mux_determine_rate(struct clk_hw *hw,
246 struct clk_rate_request *req)
248 struct ccu_mux *cm = hw_to_ccu_mux(hw);
250 if (cm->common.features & CCU_FEATURE_CLOSEST_RATE)
251 return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
253 return clk_mux_determine_rate_flags(hw, req, 0);
256 static unsigned long ccu_mux_recalc_rate(struct clk_hw *hw,
257 unsigned long parent_rate)
259 struct ccu_mux *cm = hw_to_ccu_mux(hw);
261 return ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
265 const struct clk_ops ccu_mux_ops = {
266 .disable = ccu_mux_disable,
267 .enable = ccu_mux_enable,
268 .is_enabled = ccu_mux_is_enabled,
270 .get_parent = ccu_mux_get_parent,
271 .set_parent = ccu_mux_set_parent,
273 .determine_rate = ccu_mux_determine_rate,
274 .recalc_rate = ccu_mux_recalc_rate,
276 EXPORT_SYMBOL_NS_GPL(ccu_mux_ops, SUNXI_CCU);
279 * This clock notifier is called when the frequency of the of the parent
280 * PLL clock is to be changed. The idea is to switch the parent to a
281 * stable clock, such as the main oscillator, while the PLL frequency
284 static int ccu_mux_notifier_cb(struct notifier_block *nb,
285 unsigned long event, void *data)
287 struct ccu_mux_nb *mux = to_ccu_mux_nb(nb);
290 if (event == PRE_RATE_CHANGE) {
291 mux->original_index = ccu_mux_helper_get_parent(mux->common,
293 ret = ccu_mux_helper_set_parent(mux->common, mux->cm,
295 } else if (event == POST_RATE_CHANGE) {
296 ret = ccu_mux_helper_set_parent(mux->common, mux->cm,
297 mux->original_index);
300 udelay(mux->delay_us);
302 return notifier_from_errno(ret);
305 int ccu_mux_notifier_register(struct clk *clk, struct ccu_mux_nb *mux_nb)
307 mux_nb->clk_nb.notifier_call = ccu_mux_notifier_cb;
309 return clk_notifier_register(clk, &mux_nb->clk_nb);
311 EXPORT_SYMBOL_NS_GPL(ccu_mux_notifier_register, SUNXI_CCU);