xref: /linux/drivers/clk/renesas/rcar-cpg-lib.c (revision 0678df8271820bcf8fb4f877129f05d68a237de4)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * R-Car Gen3 Clock Pulse Generator Library
4  *
5  * Copyright (C) 2015-2018 Glider bvba
6  * Copyright (C) 2019 Renesas Electronics Corp.
7  *
8  * Based on clk-rcar-gen3.c
9  *
10  * Copyright (C) 2015 Renesas Electronics Corp.
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/clk-provider.h>
15 #include <linux/device.h>
16 #include <linux/err.h>
17 #include <linux/init.h>
18 #include <linux/io.h>
19 #include <linux/pm.h>
20 #include <linux/slab.h>
21 #include <linux/sys_soc.h>
22 
23 #include "rcar-cpg-lib.h"
24 
25 spinlock_t cpg_lock;
26 
27 void cpg_reg_modify(void __iomem *reg, u32 clear, u32 set)
28 {
29 	unsigned long flags;
30 	u32 val;
31 
32 	spin_lock_irqsave(&cpg_lock, flags);
33 	val = readl(reg);
34 	val &= ~clear;
35 	val |= set;
36 	writel(val, reg);
37 	spin_unlock_irqrestore(&cpg_lock, flags);
38 };
39 
40 static int cpg_simple_notifier_call(struct notifier_block *nb,
41 				    unsigned long action, void *data)
42 {
43 	struct cpg_simple_notifier *csn =
44 		container_of(nb, struct cpg_simple_notifier, nb);
45 
46 	switch (action) {
47 	case PM_EVENT_SUSPEND:
48 		csn->saved = readl(csn->reg);
49 		return NOTIFY_OK;
50 
51 	case PM_EVENT_RESUME:
52 		writel(csn->saved, csn->reg);
53 		return NOTIFY_OK;
54 	}
55 	return NOTIFY_DONE;
56 }
57 
58 void cpg_simple_notifier_register(struct raw_notifier_head *notifiers,
59 				  struct cpg_simple_notifier *csn)
60 {
61 	csn->nb.notifier_call = cpg_simple_notifier_call;
62 	raw_notifier_chain_register(notifiers, &csn->nb);
63 }
64 
65 /*
66  * SDn Clock
67  */
68 
69 #define SDnSRCFC_SHIFT 2
70 #define STPnHCK	BIT(9 - SDnSRCFC_SHIFT)
71 
72 static const struct clk_div_table cpg_sdh_div_table[] = {
73 	/*
74 	 * These values are recommended by the datasheet.  Because they come
75 	 * first, Linux will only use these.
76 	 */
77 	{ 0, 1 }, { 1, 2 }, { STPnHCK | 2, 4 }, { STPnHCK | 3, 8 },
78 	{ STPnHCK | 4, 16 },
79 	/*
80 	 * These values are not recommended because STPnHCK is wrong.  But they
81 	 * have been seen because of broken firmware.  So, we support reading
82 	 * them but Linux will sanitize them when initializing through
83 	 * recalc_rate.
84 	 */
85 	{ STPnHCK | 0, 1 }, { STPnHCK | 1, 2 },  { 2, 4 }, { 3, 8 }, { 4, 16 },
86 	/* Sentinel */
87 	{ 0, 0 }
88 };
89 
90 struct clk * __init cpg_sdh_clk_register(const char *name,
91 	void __iomem *sdnckcr, const char *parent_name,
92 	struct raw_notifier_head *notifiers)
93 {
94 	struct cpg_simple_notifier *csn;
95 	struct clk *clk;
96 
97 	csn = kzalloc(sizeof(*csn), GFP_KERNEL);
98 	if (!csn)
99 		return ERR_PTR(-ENOMEM);
100 
101 	csn->reg = sdnckcr;
102 
103 	clk = clk_register_divider_table(NULL, name, parent_name, 0, sdnckcr,
104 					 SDnSRCFC_SHIFT, 8, 0, cpg_sdh_div_table,
105 					 &cpg_lock);
106 	if (IS_ERR(clk)) {
107 		kfree(csn);
108 		return clk;
109 	}
110 
111 	cpg_simple_notifier_register(notifiers, csn);
112 	return clk;
113 }
114 
115 static const struct clk_div_table cpg_sd_div_table[] = {
116 	{ 0, 2 }, { 1, 4 }, { 0, 0 },
117 };
118 
119 struct clk * __init cpg_sd_clk_register(const char *name,
120 	void __iomem *sdnckcr, const char *parent_name)
121 {
122 	return clk_register_divider_table(NULL, name, parent_name, 0, sdnckcr,
123 					  0, 2, 0, cpg_sd_div_table, &cpg_lock);
124 }
125 
126 struct rpc_clock {
127 	struct clk_divider div;
128 	struct clk_gate gate;
129 	/*
130 	 * One notifier covers both RPC and RPCD2 clocks as they are both
131 	 * controlled by the same RPCCKCR register...
132 	 */
133 	struct cpg_simple_notifier csn;
134 };
135 
136 static const struct clk_div_table cpg_rpc_div_table[] = {
137 	{ 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 }, { 0, 0 },
138 };
139 
140 struct clk * __init cpg_rpc_clk_register(const char *name,
141 	void __iomem *rpcckcr, const char *parent_name,
142 	struct raw_notifier_head *notifiers)
143 {
144 	struct rpc_clock *rpc;
145 	struct clk *clk;
146 
147 	rpc = kzalloc(sizeof(*rpc), GFP_KERNEL);
148 	if (!rpc)
149 		return ERR_PTR(-ENOMEM);
150 
151 	rpc->div.reg = rpcckcr;
152 	rpc->div.width = 3;
153 	rpc->div.table = cpg_rpc_div_table;
154 	rpc->div.lock = &cpg_lock;
155 
156 	rpc->gate.reg = rpcckcr;
157 	rpc->gate.bit_idx = 8;
158 	rpc->gate.flags = CLK_GATE_SET_TO_DISABLE;
159 	rpc->gate.lock = &cpg_lock;
160 
161 	rpc->csn.reg = rpcckcr;
162 
163 	clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,
164 				     &rpc->div.hw,  &clk_divider_ops,
165 				     &rpc->gate.hw, &clk_gate_ops,
166 				     CLK_SET_RATE_PARENT);
167 	if (IS_ERR(clk)) {
168 		kfree(rpc);
169 		return clk;
170 	}
171 
172 	cpg_simple_notifier_register(notifiers, &rpc->csn);
173 	return clk;
174 }
175 
176 struct rpcd2_clock {
177 	struct clk_fixed_factor fixed;
178 	struct clk_gate gate;
179 };
180 
181 struct clk * __init cpg_rpcd2_clk_register(const char *name,
182 					   void __iomem *rpcckcr,
183 					   const char *parent_name)
184 {
185 	struct rpcd2_clock *rpcd2;
186 	struct clk *clk;
187 
188 	rpcd2 = kzalloc(sizeof(*rpcd2), GFP_KERNEL);
189 	if (!rpcd2)
190 		return ERR_PTR(-ENOMEM);
191 
192 	rpcd2->fixed.mult = 1;
193 	rpcd2->fixed.div = 2;
194 
195 	rpcd2->gate.reg = rpcckcr;
196 	rpcd2->gate.bit_idx = 9;
197 	rpcd2->gate.flags = CLK_GATE_SET_TO_DISABLE;
198 	rpcd2->gate.lock = &cpg_lock;
199 
200 	clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL,
201 				     &rpcd2->fixed.hw, &clk_fixed_factor_ops,
202 				     &rpcd2->gate.hw, &clk_gate_ops,
203 				     CLK_SET_RATE_PARENT);
204 	if (IS_ERR(clk))
205 		kfree(rpcd2);
206 
207 	return clk;
208 }
209 
210