xref: /openbmc/linux/drivers/clk/ingenic/cgu.h (revision 83b975b5)
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
46  * @stable_bit: the index of the stable bit in the PLL control register
47  */
48 struct ingenic_cgu_pll_info {
49 	unsigned reg;
50 	unsigned rate_multiplier;
51 	const s8 *od_encoding;
52 	u8 m_shift, m_bits, m_offset;
53 	u8 n_shift, n_bits, n_offset;
54 	u8 od_shift, od_bits, od_max;
55 	unsigned bypass_reg;
56 	s8 bypass_bit;
57 	u8 enable_bit;
58 	u8 stable_bit;
59 	void (*calc_m_n_od)(const struct ingenic_cgu_pll_info *pll_info,
60 			    unsigned long rate, unsigned long parent_rate,
61 			    unsigned int *m, unsigned int *n, unsigned int *od);
62 };
63 
64 /**
65  * struct ingenic_cgu_mux_info - information about a clock mux
66  * @reg: offset of the mux control register within the CGU
67  * @shift: number of bits to shift the mux value by (ie. the index of
68  *         the lowest bit of the mux value within its control register)
69  * @bits: the size of the mux value in bits
70  */
71 struct ingenic_cgu_mux_info {
72 	unsigned reg;
73 	u8 shift;
74 	u8 bits;
75 };
76 
77 /**
78  * struct ingenic_cgu_div_info - information about a divider
79  * @reg: offset of the divider control register within the CGU
80  * @shift: number of bits to left shift the divide value by (ie. the index of
81  *         the lowest bit of the divide value within its control register)
82  * @div: number to divide the divider value by (i.e. if the
83  *	 effective divider value is the value written to the register
84  *	 multiplied by some constant)
85  * @bits: the size of the divide value in bits
86  * @ce_bit: the index of the change enable bit within reg, or -1 if there
87  *          isn't one
88  * @busy_bit: the index of the busy bit within reg, or -1 if there isn't one
89  * @stop_bit: the index of the stop bit within reg, or -1 if there isn't one
90  * @bypass_mask: mask of parent clocks for which the divider does not apply
91  * @div_table: optional table to map the value read from the register to the
92  *             actual divider value
93  */
94 struct ingenic_cgu_div_info {
95 	unsigned reg;
96 	u8 shift;
97 	u8 div;
98 	u8 bits;
99 	s8 ce_bit;
100 	s8 busy_bit;
101 	s8 stop_bit;
102 	u8 bypass_mask;
103 	const u8 *div_table;
104 };
105 
106 /**
107  * struct ingenic_cgu_fixdiv_info - information about a fixed divider
108  * @div: the divider applied to the parent clock
109  */
110 struct ingenic_cgu_fixdiv_info {
111 	unsigned div;
112 };
113 
114 /**
115  * struct ingenic_cgu_gate_info - information about a clock gate
116  * @reg: offset of the gate control register within the CGU
117  * @bit: offset of the bit in the register that controls the gate
118  * @clear_to_gate: if set, the clock is gated when the bit is cleared
119  * @delay_us: delay in microseconds after which the clock is considered stable
120  */
121 struct ingenic_cgu_gate_info {
122 	unsigned reg;
123 	u8 bit;
124 	bool clear_to_gate;
125 	u16 delay_us;
126 };
127 
128 /**
129  * struct ingenic_cgu_custom_info - information about a custom (SoC) clock
130  * @clk_ops: custom clock operation callbacks
131  */
132 struct ingenic_cgu_custom_info {
133 	const struct clk_ops *clk_ops;
134 };
135 
136 /**
137  * struct ingenic_cgu_clk_info - information about a clock
138  * @name: name of the clock
139  * @type: a bitmask formed from CGU_CLK_* values
140  * @flags: common clock flags to set on this clock
141  * @parents: an array of the indices of potential parents of this clock
142  *           within the clock_info array of the CGU, or -1 in entries
143  *           which correspond to no valid parent
144  * @pll: information valid if type includes CGU_CLK_PLL
145  * @gate: information valid if type includes CGU_CLK_GATE
146  * @mux: information valid if type includes CGU_CLK_MUX
147  * @div: information valid if type includes CGU_CLK_DIV
148  * @fixdiv: information valid if type includes CGU_CLK_FIXDIV
149  * @custom: information valid if type includes CGU_CLK_CUSTOM
150  */
151 struct ingenic_cgu_clk_info {
152 	const char *name;
153 
154 	enum {
155 		CGU_CLK_NONE		= 0,
156 		CGU_CLK_EXT		= BIT(0),
157 		CGU_CLK_PLL		= BIT(1),
158 		CGU_CLK_GATE		= BIT(2),
159 		CGU_CLK_MUX		= BIT(3),
160 		CGU_CLK_MUX_GLITCHFREE	= BIT(4),
161 		CGU_CLK_DIV		= BIT(5),
162 		CGU_CLK_FIXDIV		= BIT(6),
163 		CGU_CLK_CUSTOM		= BIT(7),
164 	} type;
165 
166 	unsigned long flags;
167 
168 	int parents[4];
169 
170 	union {
171 		struct ingenic_cgu_pll_info pll;
172 
173 		struct {
174 			struct ingenic_cgu_gate_info gate;
175 			struct ingenic_cgu_mux_info mux;
176 			struct ingenic_cgu_div_info div;
177 			struct ingenic_cgu_fixdiv_info fixdiv;
178 		};
179 
180 		struct ingenic_cgu_custom_info custom;
181 	};
182 };
183 
184 /**
185  * struct ingenic_cgu - data about the CGU
186  * @np: the device tree node that caused the CGU to be probed
187  * @base: the ioremap'ed base address of the CGU registers
188  * @clock_info: an array containing information about implemented clocks
189  * @clocks: used to provide clocks to DT, allows lookup of struct clk*
190  * @lock: lock to be held whilst manipulating CGU registers
191  */
192 struct ingenic_cgu {
193 	struct device_node *np;
194 	void __iomem *base;
195 
196 	const struct ingenic_cgu_clk_info *clock_info;
197 	struct clk_onecell_data clocks;
198 
199 	spinlock_t lock;
200 };
201 
202 /**
203  * struct ingenic_clk - private data for a clock
204  * @hw: see Documentation/driver-api/clk.rst
205  * @cgu: a pointer to the CGU data
206  * @idx: the index of this clock in cgu->clock_info
207  */
208 struct ingenic_clk {
209 	struct clk_hw hw;
210 	struct ingenic_cgu *cgu;
211 	unsigned idx;
212 };
213 
214 #define to_ingenic_clk(_hw) container_of(_hw, struct ingenic_clk, hw)
215 
216 /**
217  * ingenic_cgu_new() - create a new CGU instance
218  * @clock_info: an array of clock information structures describing the clocks
219  *              which are implemented by the CGU
220  * @num_clocks: the number of entries in clock_info
221  * @np: the device tree node which causes this CGU to be probed
222  *
223  * Return: a pointer to the CGU instance if initialisation is successful,
224  *         otherwise NULL.
225  */
226 struct ingenic_cgu *
227 ingenic_cgu_new(const struct ingenic_cgu_clk_info *clock_info,
228 		unsigned num_clocks, struct device_node *np);
229 
230 /**
231  * ingenic_cgu_register_clocks() - Registers the clocks
232  * @cgu: pointer to cgu data
233  *
234  * Register the clocks described by the CGU with the common clock framework.
235  *
236  * Return: 0 on success or -errno if unsuccesful.
237  */
238 int ingenic_cgu_register_clocks(struct ingenic_cgu *cgu);
239 
240 #endif /* __DRIVERS_CLK_INGENIC_CGU_H__ */
241