xref: /openbmc/linux/drivers/clk/ingenic/cgu.h (revision 63705da3)
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
37  * @od_max: the maximum post-VCO divider value
38  * @od_encoding: a pointer to an array mapping post-VCO divider values to
39  *               their encoded values in the PLL control register, or -1 for
40  *               unsupported values
41  * @bypass_reg: the offset of the bypass control register within the CGU
42  * @bypass_bit: the index of the bypass bit in the PLL control register, or
43  *              -1 if there is no bypass bit
44  * @enable_bit: the index of the enable bit in the PLL control register
45  * @stable_bit: the index of the stable bit in the PLL control register
46  */
47 struct ingenic_cgu_pll_info {
48 	unsigned reg;
49 	unsigned rate_multiplier;
50 	const s8 *od_encoding;
51 	u8 m_shift, m_bits, m_offset;
52 	u8 n_shift, n_bits, n_offset;
53 	u8 od_shift, od_bits, od_max;
54 	unsigned bypass_reg;
55 	s8 bypass_bit;
56 	u8 enable_bit;
57 	u8 stable_bit;
58 	void (*calc_m_n_od)(const struct ingenic_cgu_pll_info *pll_info,
59 			    unsigned long rate, unsigned long parent_rate,
60 			    unsigned int *m, unsigned int *n, unsigned int *od);
61 };
62 
63 /**
64  * struct ingenic_cgu_mux_info - information about a clock mux
65  * @reg: offset of the mux control register within the CGU
66  * @shift: number of bits to shift the mux value by (ie. the index of
67  *         the lowest bit of the mux value within its control register)
68  * @bits: the size of the mux value in bits
69  */
70 struct ingenic_cgu_mux_info {
71 	unsigned reg;
72 	u8 shift;
73 	u8 bits;
74 };
75 
76 /**
77  * struct ingenic_cgu_div_info - information about a divider
78  * @reg: offset of the divider control register within the CGU
79  * @shift: number of bits to left shift the divide value by (ie. the index of
80  *         the lowest bit of the divide value within its control register)
81  * @div: number to divide the divider value by (i.e. if the
82  *	 effective divider value is the value written to the register
83  *	 multiplied by some constant)
84  * @bits: the size of the divide value in bits
85  * @ce_bit: the index of the change enable bit within reg, or -1 if there
86  *          isn't one
87  * @busy_bit: the index of the busy bit within reg, or -1 if there isn't one
88  * @stop_bit: the index of the stop bit within reg, or -1 if there isn't one
89  * @bypass_mask: mask of parent clocks for which the divider does not apply
90  * @div_table: optional table to map the value read from the register to the
91  *             actual divider value
92  */
93 struct ingenic_cgu_div_info {
94 	unsigned reg;
95 	u8 shift;
96 	u8 div;
97 	u8 bits;
98 	s8 ce_bit;
99 	s8 busy_bit;
100 	s8 stop_bit;
101 	u8 bypass_mask;
102 	const u8 *div_table;
103 };
104 
105 /**
106  * struct ingenic_cgu_fixdiv_info - information about a fixed divider
107  * @div: the divider applied to the parent clock
108  */
109 struct ingenic_cgu_fixdiv_info {
110 	unsigned div;
111 };
112 
113 /**
114  * struct ingenic_cgu_gate_info - information about a clock gate
115  * @reg: offset of the gate control register within the CGU
116  * @bit: offset of the bit in the register that controls the gate
117  * @clear_to_gate: if set, the clock is gated when the bit is cleared
118  * @delay_us: delay in microseconds after which the clock is considered stable
119  */
120 struct ingenic_cgu_gate_info {
121 	unsigned reg;
122 	u8 bit;
123 	bool clear_to_gate;
124 	u16 delay_us;
125 };
126 
127 /**
128  * struct ingenic_cgu_custom_info - information about a custom (SoC) clock
129  * @clk_ops: custom clock operation callbacks
130  */
131 struct ingenic_cgu_custom_info {
132 	const struct clk_ops *clk_ops;
133 };
134 
135 /**
136  * struct ingenic_cgu_clk_info - information about a clock
137  * @name: name of the clock
138  * @type: a bitmask formed from CGU_CLK_* values
139  * @parents: an array of the indices of potential parents of this clock
140  *           within the clock_info array of the CGU, or -1 in entries
141  *           which correspond to no valid parent
142  * @pll: information valid if type includes CGU_CLK_PLL
143  * @gate: information valid if type includes CGU_CLK_GATE
144  * @mux: information valid if type includes CGU_CLK_MUX
145  * @div: information valid if type includes CGU_CLK_DIV
146  * @fixdiv: information valid if type includes CGU_CLK_FIXDIV
147  * @custom: information valid if type includes CGU_CLK_CUSTOM
148  */
149 struct ingenic_cgu_clk_info {
150 	const char *name;
151 
152 	enum {
153 		CGU_CLK_NONE		= 0,
154 		CGU_CLK_EXT		= BIT(0),
155 		CGU_CLK_PLL		= BIT(1),
156 		CGU_CLK_GATE		= BIT(2),
157 		CGU_CLK_MUX		= BIT(3),
158 		CGU_CLK_MUX_GLITCHFREE	= BIT(4),
159 		CGU_CLK_DIV		= BIT(5),
160 		CGU_CLK_FIXDIV		= BIT(6),
161 		CGU_CLK_CUSTOM		= BIT(7),
162 	} type;
163 
164 	int parents[4];
165 
166 	union {
167 		struct ingenic_cgu_pll_info pll;
168 
169 		struct {
170 			struct ingenic_cgu_gate_info gate;
171 			struct ingenic_cgu_mux_info mux;
172 			struct ingenic_cgu_div_info div;
173 			struct ingenic_cgu_fixdiv_info fixdiv;
174 		};
175 
176 		struct ingenic_cgu_custom_info custom;
177 	};
178 };
179 
180 /**
181  * struct ingenic_cgu - data about the CGU
182  * @np: the device tree node that caused the CGU to be probed
183  * @base: the ioremap'ed base address of the CGU registers
184  * @clock_info: an array containing information about implemented clocks
185  * @clocks: used to provide clocks to DT, allows lookup of struct clk*
186  * @lock: lock to be held whilst manipulating CGU registers
187  */
188 struct ingenic_cgu {
189 	struct device_node *np;
190 	void __iomem *base;
191 
192 	const struct ingenic_cgu_clk_info *clock_info;
193 	struct clk_onecell_data clocks;
194 
195 	spinlock_t lock;
196 };
197 
198 /**
199  * struct ingenic_clk - private data for a clock
200  * @hw: see Documentation/driver-api/clk.rst
201  * @cgu: a pointer to the CGU data
202  * @idx: the index of this clock in cgu->clock_info
203  */
204 struct ingenic_clk {
205 	struct clk_hw hw;
206 	struct ingenic_cgu *cgu;
207 	unsigned idx;
208 };
209 
210 #define to_ingenic_clk(_hw) container_of(_hw, struct ingenic_clk, hw)
211 
212 /**
213  * ingenic_cgu_new() - create a new CGU instance
214  * @clock_info: an array of clock information structures describing the clocks
215  *              which are implemented by the CGU
216  * @num_clocks: the number of entries in clock_info
217  * @np: the device tree node which causes this CGU to be probed
218  *
219  * Return: a pointer to the CGU instance if initialisation is successful,
220  *         otherwise NULL.
221  */
222 struct ingenic_cgu *
223 ingenic_cgu_new(const struct ingenic_cgu_clk_info *clock_info,
224 		unsigned num_clocks, struct device_node *np);
225 
226 /**
227  * ingenic_cgu_register_clocks() - Registers the clocks
228  * @cgu: pointer to cgu data
229  *
230  * Register the clocks described by the CGU with the common clock framework.
231  *
232  * Return: 0 on success or -errno if unsuccesful.
233  */
234 int ingenic_cgu_register_clocks(struct ingenic_cgu *cgu);
235 
236 #endif /* __DRIVERS_CLK_INGENIC_CGU_H__ */
237