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1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Ingenic SoC CGU driver
4  *
5  * Copyright (c) 2013-2015 Imagination Technologies
6  * Author: Paul Burton <paul.burton@mips.com>
7  */
8 
9 #ifndef __DRIVERS_CLK_INGENIC_CGU_H__
10 #define __DRIVERS_CLK_INGENIC_CGU_H__
11 
12 #include <linux/bitops.h>
13 #include <linux/clk-provider.h>
14 #include <linux/of.h>
15 #include <linux/spinlock.h>
16 
17 /**
18  * struct ingenic_cgu_pll_info - information about a PLL
19  * @reg: the offset of the PLL's control register within the CGU
20  * @rate_multiplier: the multiplier needed by pll rate calculation
21  * @m_shift: the number of bits to shift the multiplier value by (ie. the
22  *           index of the lowest bit of the multiplier value in the PLL's
23  *           control register)
24  * @m_bits: the size of the multiplier field in bits
25  * @m_offset: the multiplier value which encodes to 0 in the PLL's control
26  *            register
27  * @n_shift: the number of bits to shift the divider value by (ie. the
28  *           index of the lowest bit of the divider value in the PLL's
29  *           control register)
30  * @n_bits: the size of the divider field in bits
31  * @n_offset: the divider value which encodes to 0 in the PLL's control
32  *            register
33  * @od_shift: the number of bits to shift the post-VCO divider value by (ie.
34  *            the index of the lowest bit of the post-VCO divider value in
35  *            the PLL's control register)
36  * @od_bits: the size of the post-VCO divider field in bits, or 0 if no
37  *	     OD field exists (then the OD is fixed to 1)
38  * @od_max: the maximum post-VCO divider value
39  * @od_encoding: a pointer to an array mapping post-VCO divider values to
40  *               their encoded values in the PLL control register, or -1 for
41  *               unsupported values
42  * @bypass_reg: the offset of the bypass control register within the CGU
43  * @bypass_bit: the index of the bypass bit in the PLL control register, or
44  *              -1 if there is no bypass bit
45  * @enable_bit: the index of the enable bit in the PLL control register, or
46  *		-1 if there is no enable bit (ie, the PLL is always on)
47  * @stable_bit: the index of the stable bit in the PLL control register, or
48  *		-1 if there is no stable bit
49  * @set_rate_hook: hook called immediately after updating the CGU register,
50  *		   before releasing the spinlock
51  */
52 struct ingenic_cgu_pll_info {
53 	unsigned reg;
54 	unsigned rate_multiplier;
55 	const s8 *od_encoding;
56 	u8 m_shift, m_bits, m_offset;
57 	u8 n_shift, n_bits, n_offset;
58 	u8 od_shift, od_bits, od_max;
59 	unsigned bypass_reg;
60 	s8 bypass_bit;
61 	s8 enable_bit;
62 	s8 stable_bit;
63 	void (*calc_m_n_od)(const struct ingenic_cgu_pll_info *pll_info,
64 			    unsigned long rate, unsigned long parent_rate,
65 			    unsigned int *m, unsigned int *n, unsigned int *od);
66 	void (*set_rate_hook)(const struct ingenic_cgu_pll_info *pll_info,
67 			      unsigned long rate, unsigned long parent_rate);
68 };
69 
70 /**
71  * struct ingenic_cgu_mux_info - information about a clock mux
72  * @reg: offset of the mux control register within the CGU
73  * @shift: number of bits to shift the mux value by (ie. the index of
74  *         the lowest bit of the mux value within its control register)
75  * @bits: the size of the mux value in bits
76  */
77 struct ingenic_cgu_mux_info {
78 	unsigned reg;
79 	u8 shift;
80 	u8 bits;
81 };
82 
83 /**
84  * struct ingenic_cgu_div_info - information about a divider
85  * @reg: offset of the divider control register within the CGU
86  * @shift: number of bits to left shift the divide value by (ie. the index of
87  *         the lowest bit of the divide value within its control register)
88  * @div: number to divide the divider value by (i.e. if the
89  *	 effective divider value is the value written to the register
90  *	 multiplied by some constant)
91  * @bits: the size of the divide value in bits
92  * @ce_bit: the index of the change enable bit within reg, or -1 if there
93  *          isn't one
94  * @busy_bit: the index of the busy bit within reg, or -1 if there isn't one
95  * @stop_bit: the index of the stop bit within reg, or -1 if there isn't one
96  * @bypass_mask: mask of parent clocks for which the divider does not apply
97  * @div_table: optional table to map the value read from the register to the
98  *             actual divider value
99  */
100 struct ingenic_cgu_div_info {
101 	unsigned reg;
102 	u8 shift;
103 	u8 div;
104 	u8 bits;
105 	s8 ce_bit;
106 	s8 busy_bit;
107 	s8 stop_bit;
108 	u8 bypass_mask;
109 	const u8 *div_table;
110 };
111 
112 /**
113  * struct ingenic_cgu_fixdiv_info - information about a fixed divider
114  * @div: the divider applied to the parent clock
115  */
116 struct ingenic_cgu_fixdiv_info {
117 	unsigned div;
118 };
119 
120 /**
121  * struct ingenic_cgu_gate_info - information about a clock gate
122  * @reg: offset of the gate control register within the CGU
123  * @bit: offset of the bit in the register that controls the gate
124  * @clear_to_gate: if set, the clock is gated when the bit is cleared
125  * @delay_us: delay in microseconds after which the clock is considered stable
126  */
127 struct ingenic_cgu_gate_info {
128 	unsigned reg;
129 	u8 bit;
130 	bool clear_to_gate;
131 	u16 delay_us;
132 };
133 
134 /**
135  * struct ingenic_cgu_custom_info - information about a custom (SoC) clock
136  * @clk_ops: custom clock operation callbacks
137  */
138 struct ingenic_cgu_custom_info {
139 	const struct clk_ops *clk_ops;
140 };
141 
142 /**
143  * struct ingenic_cgu_clk_info - information about a clock
144  * @name: name of the clock
145  * @type: a bitmask formed from CGU_CLK_* values
146  * @flags: common clock flags to set on this clock
147  * @parents: an array of the indices of potential parents of this clock
148  *           within the clock_info array of the CGU, or -1 in entries
149  *           which correspond to no valid parent
150  * @pll: information valid if type includes CGU_CLK_PLL
151  * @gate: information valid if type includes CGU_CLK_GATE
152  * @mux: information valid if type includes CGU_CLK_MUX
153  * @div: information valid if type includes CGU_CLK_DIV
154  * @fixdiv: information valid if type includes CGU_CLK_FIXDIV
155  * @custom: information valid if type includes CGU_CLK_CUSTOM
156  */
157 struct ingenic_cgu_clk_info {
158 	const char *name;
159 
160 	enum {
161 		CGU_CLK_NONE		= 0,
162 		CGU_CLK_EXT		= BIT(0),
163 		CGU_CLK_PLL		= BIT(1),
164 		CGU_CLK_GATE		= BIT(2),
165 		CGU_CLK_MUX		= BIT(3),
166 		CGU_CLK_MUX_GLITCHFREE	= BIT(4),
167 		CGU_CLK_DIV		= BIT(5),
168 		CGU_CLK_FIXDIV		= BIT(6),
169 		CGU_CLK_CUSTOM		= BIT(7),
170 	} type;
171 
172 	unsigned long flags;
173 
174 	int parents[4];
175 
176 	union {
177 		struct ingenic_cgu_pll_info pll;
178 
179 		struct {
180 			struct ingenic_cgu_gate_info gate;
181 			struct ingenic_cgu_mux_info mux;
182 			struct ingenic_cgu_div_info div;
183 			struct ingenic_cgu_fixdiv_info fixdiv;
184 		};
185 
186 		struct ingenic_cgu_custom_info custom;
187 	};
188 };
189 
190 /**
191  * struct ingenic_cgu - data about the CGU
192  * @np: the device tree node that caused the CGU to be probed
193  * @base: the ioremap'ed base address of the CGU registers
194  * @clock_info: an array containing information about implemented clocks
195  * @clocks: used to provide clocks to DT, allows lookup of struct clk*
196  * @lock: lock to be held whilst manipulating CGU registers
197  */
198 struct ingenic_cgu {
199 	struct device_node *np;
200 	void __iomem *base;
201 
202 	const struct ingenic_cgu_clk_info *clock_info;
203 	struct clk_onecell_data clocks;
204 
205 	spinlock_t lock;
206 };
207 
208 /**
209  * struct ingenic_clk - private data for a clock
210  * @hw: see Documentation/driver-api/clk.rst
211  * @cgu: a pointer to the CGU data
212  * @idx: the index of this clock in cgu->clock_info
213  */
214 struct ingenic_clk {
215 	struct clk_hw hw;
216 	struct ingenic_cgu *cgu;
217 	unsigned idx;
218 };
219 
220 #define to_ingenic_clk(_hw) container_of(_hw, struct ingenic_clk, hw)
221 
222 /**
223  * ingenic_cgu_new() - create a new CGU instance
224  * @clock_info: an array of clock information structures describing the clocks
225  *              which are implemented by the CGU
226  * @num_clocks: the number of entries in clock_info
227  * @np: the device tree node which causes this CGU to be probed
228  *
229  * Return: a pointer to the CGU instance if initialisation is successful,
230  *         otherwise NULL.
231  */
232 struct ingenic_cgu *
233 ingenic_cgu_new(const struct ingenic_cgu_clk_info *clock_info,
234 		unsigned num_clocks, struct device_node *np);
235 
236 /**
237  * ingenic_cgu_register_clocks() - Registers the clocks
238  * @cgu: pointer to cgu data
239  *
240  * Register the clocks described by the CGU with the common clock framework.
241  *
242  * Return: 0 on success or -errno if unsuccesful.
243  */
244 int ingenic_cgu_register_clocks(struct ingenic_cgu *cgu);
245 
246 #endif /* __DRIVERS_CLK_INGENIC_CGU_H__ */
247