1 /*
2  * Renesas RCar Gen3 CPG MSSR driver
3  *
4  * Copyright (C) 2018 Marek Vasut <marek.vasut@gmail.com>
5  *
6  * Based on the following driver from Linux kernel:
7  * r8a7796 Clock Pulse Generator / Module Standby and Software Reset
8  *
9  * Copyright (C) 2016 Glider bvba
10  *
11  * SPDX-License-Identifier:	GPL-2.0+
12  */
13 #include <common.h>
14 #include <clk-uclass.h>
15 #include <dm.h>
16 #include <errno.h>
17 #include <wait_bit.h>
18 #include <asm/io.h>
19 
20 #include <dt-bindings/clock/renesas-cpg-mssr.h>
21 
22 #include "renesas-cpg-mssr.h"
23 
24 /*
25  * Module Standby and Software Reset register offets.
26  *
27  * If the registers exist, these are valid for SH-Mobile, R-Mobile,
28  * R-Car Gen2, R-Car Gen3, and RZ/G1.
29  * These are NOT valid for R-Car Gen1 and RZ/A1!
30  */
31 
32 /*
33  * Module Stop Status Register offsets
34  */
35 
36 static const u16 mstpsr[] = {
37 	0x030, 0x038, 0x040, 0x048, 0x04C, 0x03C, 0x1C0, 0x1C4,
38 	0x9A0, 0x9A4, 0x9A8, 0x9AC,
39 };
40 
41 #define	MSTPSR(i)	mstpsr[i]
42 
43 
44 /*
45  * System Module Stop Control Register offsets
46  */
47 
48 static const u16 smstpcr[] = {
49 	0x130, 0x134, 0x138, 0x13C, 0x140, 0x144, 0x148, 0x14C,
50 	0x990, 0x994, 0x998, 0x99C,
51 };
52 
53 #define	SMSTPCR(i)	smstpcr[i]
54 
55 
56 /* Realtime Module Stop Control Register offsets */
57 #define RMSTPCR(i)	(smstpcr[i] - 0x20)
58 
59 /* Modem Module Stop Control Register offsets (r8a73a4) */
60 #define MMSTPCR(i)	(smstpcr[i] + 0x20)
61 
62 /* Software Reset Clearing Register offsets */
63 #define	SRSTCLR(i)	(0x940 + (i) * 4)
64 
65 bool renesas_clk_is_mod(struct clk *clk)
66 {
67 	return (clk->id >> 16) == CPG_MOD;
68 }
69 
70 int renesas_clk_get_mod(struct clk *clk, struct cpg_mssr_info *info,
71 			const struct mssr_mod_clk **mssr)
72 {
73 	const unsigned long clkid = clk->id & 0xffff;
74 	int i;
75 
76 	for (i = 0; i < info->mod_clk_size; i++) {
77 		if (info->mod_clk[i].id !=
78 		    (info->mod_clk_base + MOD_CLK_PACK(clkid)))
79 			continue;
80 
81 		*mssr = &info->mod_clk[i];
82 		return 0;
83 	}
84 
85 	return -ENODEV;
86 }
87 
88 int renesas_clk_get_core(struct clk *clk, struct cpg_mssr_info *info,
89 			 const struct cpg_core_clk **core)
90 {
91 	const unsigned long clkid = clk->id & 0xffff;
92 	int i;
93 
94 	for (i = 0; i < info->core_clk_size; i++) {
95 		if (info->core_clk[i].id != clkid)
96 			continue;
97 
98 		*core = &info->core_clk[i];
99 		return 0;
100 	}
101 
102 	return -ENODEV;
103 }
104 
105 int renesas_clk_get_parent(struct clk *clk, struct cpg_mssr_info *info,
106 			   struct clk *parent)
107 {
108 	const struct cpg_core_clk *core;
109 	const struct mssr_mod_clk *mssr;
110 	int ret;
111 
112 	if (renesas_clk_is_mod(clk)) {
113 		ret = renesas_clk_get_mod(clk, info, &mssr);
114 		if (ret)
115 			return ret;
116 
117 		parent->id = mssr->parent;
118 	} else {
119 		ret = renesas_clk_get_core(clk, info, &core);
120 		if (ret)
121 			return ret;
122 
123 		if (core->type == CLK_TYPE_IN)
124 			parent->id = ~0;	/* Top-level clock */
125 		else
126 			parent->id = core->parent;
127 	}
128 
129 	parent->dev = clk->dev;
130 
131 	return 0;
132 }
133 
134 int renesas_clk_endisable(struct clk *clk, void __iomem *base, bool enable)
135 {
136 	const unsigned long clkid = clk->id & 0xffff;
137 	const unsigned int reg = clkid / 100;
138 	const unsigned int bit = clkid % 100;
139 	const u32 bitmask = BIT(bit);
140 
141 	if (!renesas_clk_is_mod(clk))
142 		return -EINVAL;
143 
144 	debug("%s[%i] MSTP %lu=%02u/%02u %s\n", __func__, __LINE__,
145 	      clkid, reg, bit, enable ? "ON" : "OFF");
146 
147 	if (enable) {
148 		clrbits_le32(base + SMSTPCR(reg), bitmask);
149 		return wait_for_bit_le32(base + MSTPSR(reg),
150 				    bitmask, 0, 100, 0);
151 	} else {
152 		setbits_le32(base + SMSTPCR(reg), bitmask);
153 		return 0;
154 	}
155 }
156 
157 int renesas_clk_remove(void __iomem *base, struct cpg_mssr_info *info)
158 {
159 	unsigned int i;
160 
161 	/* Stop TMU0 */
162 	clrbits_le32(TMU_BASE + TSTR0, TSTR0_STR0);
163 
164 	/* Stop module clock */
165 	for (i = 0; i < info->mstp_table_size; i++) {
166 		clrsetbits_le32(base + SMSTPCR(i),
167 				info->mstp_table[i].sdis,
168 				info->mstp_table[i].sen);
169 		clrsetbits_le32(base + RMSTPCR(i),
170 				info->mstp_table[i].rdis,
171 				info->mstp_table[i].ren);
172 	}
173 
174 	return 0;
175 }
176