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
25spinlock_t cpg_lock;
26
27void 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
40static 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
58void 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
72static 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
90struct 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
115static const struct clk_div_table cpg_sd_div_table[] = {
116	{ 0, 2 }, { 1, 4 }, { 0, 0 },
117};
118
119struct 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
126struct 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
136static const struct clk_div_table cpg_rpc_div_table[] = {
137	{ 1, 2 }, { 3, 4 }, { 5, 6 }, { 7, 8 }, { 0, 0 },
138};
139
140struct 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
176struct rpcd2_clock {
177	struct clk_fixed_factor fixed;
178	struct clk_gate gate;
179};
180
181struct 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