1 // SPDX-License-Identifier: GPL-2.0
5  *  Copyright (C) 2016-2019 Xilinx
7  * Adjustable divider clock implementation
11 #include <linux/clk-provider.h>
13 #include "clk-zynqmp.h"
16  * DOC: basic adjustable divider clock that cannot gate
18  * Traits of this clock:
19  * prepare - clk_prepare only ensures that parents are prepared
20  * enable - clk_enable only ensures that parents are enabled
21  * rate - rate is adjustable.  clk->rate = ceiling(parent->rate / divisor)
22  * parent - fixed parent.  No clk_set_parent support
32  * struct zynqmp_clk_divider - adjustable divider clock
33  * @hw:		handle between common and hardware-specific interfaces
36  * @clk_id:	Id of clock
65 		return (rate - up_rate) <= (down_rate - rate) ? up : down;  in zynqmp_divider_get_val()
73  * zynqmp_clk_divider_recalc_rate() - Recalc rate of divider clock
74  * @hw:			handle between common and hardware-specific interfaces
75  * @parent_rate:	rate of parent clock
84 	u32 clk_id = divider->clk_id;  in zynqmp_clk_divider_recalc_rate()
85 	u32 div_type = divider->div_type;  in zynqmp_clk_divider_recalc_rate()
86 	u32 div, value;  in zynqmp_clk_divider_recalc_rate()  local
89 	ret = zynqmp_pm_clock_getdivider(clk_id, &div);  in zynqmp_clk_divider_recalc_rate()
96 		value = div & 0xFFFF;  in zynqmp_clk_divider_recalc_rate()
98 		value = div >> 16;  in zynqmp_clk_divider_recalc_rate()
100 	if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)  in zynqmp_clk_divider_recalc_rate()
104 		WARN(!(divider->flags & CLK_DIVIDER_ALLOW_ZERO),  in zynqmp_clk_divider_recalc_rate()
136 	for (div1 = 1; div1 <= pdivider->max_div;) {  in zynqmp_get_divider2_val()
137 		for (div2 = 1; div2 <= divider->max_div;) {  in zynqmp_get_divider2_val()
138 			long new_error = ((div1_prate / div1) / div2) - rate;  in zynqmp_get_divider2_val()
144 			if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)  in zynqmp_get_divider2_val()
149 		if (pdivider->flags & CLK_DIVIDER_POWER_OF_TWO)  in zynqmp_get_divider2_val()
157  * zynqmp_clk_divider_round_rate() - Round rate of divider clock
158  * @hw:			handle between common and hardware-specific interfaces
159  * @rate:		rate of clock to be set
160  * @prate:		rate of parent clock
170 	u32 clk_id = divider->clk_id;  in zynqmp_clk_divider_round_rate()
171 	u32 div_type = divider->div_type;  in zynqmp_clk_divider_round_rate()
176 	if (divider->flags & CLK_DIVIDER_READ_ONLY) {  in zynqmp_clk_divider_round_rate()
187 		if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)  in zynqmp_clk_divider_round_rate()
193 	bestdiv = zynqmp_divider_get_val(*prate, rate, divider->flags);  in zynqmp_clk_divider_round_rate()
205 	if ((clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) && divider->is_frac)  in zynqmp_clk_divider_round_rate()
208 	bestdiv = min_t(u32, bestdiv, divider->max_div);  in zynqmp_clk_divider_round_rate()
215  * zynqmp_clk_divider_set_rate() - Set rate of divider clock
216  * @hw:			handle between common and hardware-specific interfaces
217  * @rate:		rate of clock to be set
218  * @parent_rate:	rate of parent clock
227 	u32 clk_id = divider->clk_id;  in zynqmp_clk_divider_set_rate()
228 	u32 div_type = divider->div_type;  in zynqmp_clk_divider_set_rate()
229 	u32 value, div;  in zynqmp_clk_divider_set_rate()  local
232 	value = zynqmp_divider_get_val(parent_rate, rate, divider->flags);  in zynqmp_clk_divider_set_rate()
234 		div = value & 0xFFFF;  in zynqmp_clk_divider_set_rate()
235 		div |= 0xffff << 16;  in zynqmp_clk_divider_set_rate()
237 		div = 0xffff;  in zynqmp_clk_divider_set_rate()
238 		div |= value << 16;  in zynqmp_clk_divider_set_rate()
241 	if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)  in zynqmp_clk_divider_set_rate()
242 		div = __ffs(div);  in zynqmp_clk_divider_set_rate()
244 	ret = zynqmp_pm_clock_setdivider(clk_id, div);  in zynqmp_clk_divider_set_rate()
265  * zynqmp_clk_get_max_divisor() - Get maximum supported divisor from firmware.
266  * @clk_id:		Id of clock
269  * Return: Maximum divisor of a clock if query data is successful
316  * zynqmp_clk_register_divider() - Register a divider clock
317  * @name:		Name of this clock
318  * @clk_id:		Id of clock
319  * @parents:		Name of this clock's parents
321  * @nodes:		Clock topology node
323  * Return: clock hardware to registered clock divider
331 	struct zynqmp_clk_divider *div;  in zynqmp_clk_register_divider()  local
337 	div = kzalloc(sizeof(*div), GFP_KERNEL);  in zynqmp_clk_register_divider()
338 	if (!div)  in zynqmp_clk_register_divider()
339 		return ERR_PTR(-ENOMEM);  in zynqmp_clk_register_divider()
342 	if (nodes->type_flag & CLK_DIVIDER_READ_ONLY)  in zynqmp_clk_register_divider()
347 	init.flags = zynqmp_clk_map_common_ccf_flags(nodes->flag);  in zynqmp_clk_register_divider()
353 	div->is_frac = !!((nodes->flag & CLK_FRAC) |  in zynqmp_clk_register_divider()
354 			  (nodes->custom_type_flag & CUSTOM_FLAG_CLK_FRAC));  in zynqmp_clk_register_divider()
355 	div->flags = zynqmp_clk_map_divider_ccf_flags(nodes->type_flag);  in zynqmp_clk_register_divider()
356 	div->hw.init = &init;  in zynqmp_clk_register_divider()
357 	div->clk_id = clk_id;  in zynqmp_clk_register_divider()
358 	div->div_type = nodes->type;  in zynqmp_clk_register_divider()
364 	div->max_div = zynqmp_clk_get_max_divisor(clk_id, nodes->type);  in zynqmp_clk_register_divider()
366 	hw = &div->hw;  in zynqmp_clk_register_divider()
369 		kfree(div);  in zynqmp_clk_register_divider()