xref: /linux/drivers/clk/ingenic/cgu.h (revision 132db93572821ec2fdf81e354cc40f558faf7e4f)
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
43  * @enable_bit: the index of the enable bit in the PLL control register
44  * @stable_bit: the index of the stable bit in the PLL control register
45  * @no_bypass_bit: if set, the PLL has no bypass functionality
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 	u8 bypass_bit;
56 	u8 enable_bit;
57 	u8 stable_bit;
58 	bool no_bypass_bit;
59 };
60 
61 /**
62  * struct ingenic_cgu_mux_info - information about a clock mux
63  * @reg: offset of the mux control register within the CGU
64  * @shift: number of bits to shift the mux value by (ie. the index of
65  *         the lowest bit of the mux value within its control register)
66  * @bits: the size of the mux value in bits
67  */
68 struct ingenic_cgu_mux_info {
69 	unsigned reg;
70 	u8 shift;
71 	u8 bits;
72 };
73 
74 /**
75  * struct ingenic_cgu_div_info - information about a divider
76  * @reg: offset of the divider control register within the CGU
77  * @shift: number of bits to left shift the divide value by (ie. the index of
78  *         the lowest bit of the divide value within its control register)
79  * @div: number to divide the divider value by (i.e. if the
80  *	 effective divider value is the value written to the register
81  *	 multiplied by some constant)
82  * @bits: the size of the divide value in bits
83  * @ce_bit: the index of the change enable bit within reg, or -1 if there
84  *          isn't one
85  * @busy_bit: the index of the busy bit within reg, or -1 if there isn't one
86  * @stop_bit: the index of the stop bit within reg, or -1 if there isn't one
87  * @div_table: optional table to map the value read from the register to the
88  *             actual divider value
89  */
90 struct ingenic_cgu_div_info {
91 	unsigned reg;
92 	u8 shift;
93 	u8 div;
94 	u8 bits;
95 	s8 ce_bit;
96 	s8 busy_bit;
97 	s8 stop_bit;
98 	const u8 *div_table;
99 };
100 
101 /**
102  * struct ingenic_cgu_fixdiv_info - information about a fixed divider
103  * @div: the divider applied to the parent clock
104  */
105 struct ingenic_cgu_fixdiv_info {
106 	unsigned div;
107 };
108 
109 /**
110  * struct ingenic_cgu_gate_info - information about a clock gate
111  * @reg: offset of the gate control register within the CGU
112  * @bit: offset of the bit in the register that controls the gate
113  * @clear_to_gate: if set, the clock is gated when the bit is cleared
114  * @delay_us: delay in microseconds after which the clock is considered stable
115  */
116 struct ingenic_cgu_gate_info {
117 	unsigned reg;
118 	u8 bit;
119 	bool clear_to_gate;
120 	u16 delay_us;
121 };
122 
123 /**
124  * struct ingenic_cgu_custom_info - information about a custom (SoC) clock
125  * @clk_ops: custom clock operation callbacks
126  */
127 struct ingenic_cgu_custom_info {
128 	const struct clk_ops *clk_ops;
129 };
130 
131 /**
132  * struct ingenic_cgu_clk_info - information about a clock
133  * @name: name of the clock
134  * @type: a bitmask formed from CGU_CLK_* values
135  * @parents: an array of the indices of potential parents of this clock
136  *           within the clock_info array of the CGU, or -1 in entries
137  *           which correspond to no valid parent
138  * @pll: information valid if type includes CGU_CLK_PLL
139  * @gate: information valid if type includes CGU_CLK_GATE
140  * @mux: information valid if type includes CGU_CLK_MUX
141  * @div: information valid if type includes CGU_CLK_DIV
142  * @fixdiv: information valid if type includes CGU_CLK_FIXDIV
143  * @custom: information valid if type includes CGU_CLK_CUSTOM
144  */
145 struct ingenic_cgu_clk_info {
146 	const char *name;
147 
148 	enum {
149 		CGU_CLK_NONE		= 0,
150 		CGU_CLK_EXT		= BIT(0),
151 		CGU_CLK_PLL		= BIT(1),
152 		CGU_CLK_GATE		= BIT(2),
153 		CGU_CLK_MUX		= BIT(3),
154 		CGU_CLK_MUX_GLITCHFREE	= BIT(4),
155 		CGU_CLK_DIV		= BIT(5),
156 		CGU_CLK_FIXDIV		= BIT(6),
157 		CGU_CLK_CUSTOM		= BIT(7),
158 	} type;
159 
160 	int parents[4];
161 
162 	union {
163 		struct ingenic_cgu_pll_info pll;
164 
165 		struct {
166 			struct ingenic_cgu_gate_info gate;
167 			struct ingenic_cgu_mux_info mux;
168 			struct ingenic_cgu_div_info div;
169 			struct ingenic_cgu_fixdiv_info fixdiv;
170 		};
171 
172 		struct ingenic_cgu_custom_info custom;
173 	};
174 };
175 
176 /**
177  * struct ingenic_cgu - data about the CGU
178  * @np: the device tree node that caused the CGU to be probed
179  * @base: the ioremap'ed base address of the CGU registers
180  * @clock_info: an array containing information about implemented clocks
181  * @clocks: used to provide clocks to DT, allows lookup of struct clk*
182  * @lock: lock to be held whilst manipulating CGU registers
183  */
184 struct ingenic_cgu {
185 	struct device_node *np;
186 	void __iomem *base;
187 
188 	const struct ingenic_cgu_clk_info *clock_info;
189 	struct clk_onecell_data clocks;
190 
191 	spinlock_t lock;
192 };
193 
194 /**
195  * struct ingenic_clk - private data for a clock
196  * @hw: see Documentation/driver-api/clk.rst
197  * @cgu: a pointer to the CGU data
198  * @idx: the index of this clock in cgu->clock_info
199  */
200 struct ingenic_clk {
201 	struct clk_hw hw;
202 	struct ingenic_cgu *cgu;
203 	unsigned idx;
204 };
205 
206 #define to_ingenic_clk(_hw) container_of(_hw, struct ingenic_clk, hw)
207 
208 /**
209  * ingenic_cgu_new() - create a new CGU instance
210  * @clock_info: an array of clock information structures describing the clocks
211  *              which are implemented by the CGU
212  * @num_clocks: the number of entries in clock_info
213  * @np: the device tree node which causes this CGU to be probed
214  *
215  * Return: a pointer to the CGU instance if initialisation is successful,
216  *         otherwise NULL.
217  */
218 struct ingenic_cgu *
219 ingenic_cgu_new(const struct ingenic_cgu_clk_info *clock_info,
220 		unsigned num_clocks, struct device_node *np);
221 
222 /**
223  * ingenic_cgu_register_clocks() - Registers the clocks
224  * @cgu: pointer to cgu data
225  *
226  * Register the clocks described by the CGU with the common clock framework.
227  *
228  * Return: 0 on success or -errno if unsuccesful.
229  */
230 int ingenic_cgu_register_clocks(struct ingenic_cgu *cgu);
231 
232 #endif /* __DRIVERS_CLK_INGENIC_CGU_H__ */
233