1// SPDX-License-Identifier: GPL-2.0
2/*
3 * sh73a0 Core CPG Clocks
4 *
5 * Copyright (C) 2014  Ulrich Hecht
6 */
7
8#include <linux/clk-provider.h>
9#include <linux/clk/renesas.h>
10#include <linux/init.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/of.h>
14#include <linux/of_address.h>
15#include <linux/slab.h>
16#include <linux/spinlock.h>
17
18struct sh73a0_cpg {
19	struct clk_onecell_data data;
20	spinlock_t lock;
21	void __iomem *reg;
22};
23
24#define CPG_FRQCRA	0x00
25#define CPG_FRQCRB	0x04
26#define CPG_SD0CKCR	0x74
27#define CPG_SD1CKCR	0x78
28#define CPG_SD2CKCR	0x7c
29#define CPG_PLLECR	0xd0
30#define CPG_PLL0CR	0xd8
31#define CPG_PLL1CR	0x28
32#define CPG_PLL2CR	0x2c
33#define CPG_PLL3CR	0xdc
34#define CPG_CKSCR	0xc0
35#define CPG_DSI0PHYCR	0x6c
36#define CPG_DSI1PHYCR	0x70
37
38#define CLK_ENABLE_ON_INIT BIT(0)
39
40struct div4_clk {
41	const char *name;
42	const char *parent;
43	unsigned int reg;
44	unsigned int shift;
45};
46
47static const struct div4_clk div4_clks[] = {
48	{ "zg", "pll0", CPG_FRQCRA, 16 },
49	{ "m3", "pll1", CPG_FRQCRA, 12 },
50	{ "b",  "pll1", CPG_FRQCRA,  8 },
51	{ "m1", "pll1", CPG_FRQCRA,  4 },
52	{ "m2", "pll1", CPG_FRQCRA,  0 },
53	{ "zx", "pll1", CPG_FRQCRB, 12 },
54	{ "hp", "pll1", CPG_FRQCRB,  4 },
55	{ NULL, NULL, 0, 0 },
56};
57
58static const struct clk_div_table div4_div_table[] = {
59	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
60	{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
61	{ 12, 7 }, { 0, 0 }
62};
63
64static const struct clk_div_table z_div_table[] = {
65	/* ZSEL == 0 */
66	{ 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 }, { 4, 1 }, { 5, 1 },
67	{ 6, 1 }, { 7, 1 }, { 8, 1 }, { 9, 1 }, { 10, 1 }, { 11, 1 },
68	{ 12, 1 }, { 13, 1 }, { 14, 1 }, { 15, 1 },
69	/* ZSEL == 1 */
70	{ 16, 2 }, { 17, 3 }, { 18, 4 }, { 19, 6 }, { 20, 8 }, { 21, 12 },
71	{ 22, 16 }, { 24, 24 }, { 27, 48 }, { 0, 0 }
72};
73
74static struct clk * __init
75sh73a0_cpg_register_clock(struct device_node *np, struct sh73a0_cpg *cpg,
76			     const char *name)
77{
78	const struct clk_div_table *table = NULL;
79	unsigned int shift, reg, width;
80	const char *parent_name = NULL;
81	unsigned int mult = 1;
82	unsigned int div = 1;
83
84	if (!strcmp(name, "main")) {
85		/* extal1, extal1_div2, extal2, extal2_div2 */
86		u32 parent_idx = (readl(cpg->reg + CPG_CKSCR) >> 28) & 3;
87
88		parent_name = of_clk_get_parent_name(np, parent_idx >> 1);
89		div = (parent_idx & 1) + 1;
90	} else if (!strncmp(name, "pll", 3)) {
91		void __iomem *enable_reg = cpg->reg;
92		u32 enable_bit = name[3] - '0';
93
94		parent_name = "main";
95		switch (enable_bit) {
96		case 0:
97			enable_reg += CPG_PLL0CR;
98			break;
99		case 1:
100			enable_reg += CPG_PLL1CR;
101			break;
102		case 2:
103			enable_reg += CPG_PLL2CR;
104			break;
105		case 3:
106			enable_reg += CPG_PLL3CR;
107			break;
108		default:
109			return ERR_PTR(-EINVAL);
110		}
111		if (readl(cpg->reg + CPG_PLLECR) & BIT(enable_bit)) {
112			mult = ((readl(enable_reg) >> 24) & 0x3f) + 1;
113			/* handle CFG bit for PLL1 and PLL2 */
114			if (enable_bit == 1 || enable_bit == 2)
115				if (readl(enable_reg) & BIT(20))
116					mult *= 2;
117		}
118	} else if (!strcmp(name, "dsi0phy") || !strcmp(name, "dsi1phy")) {
119		u32 phy_no = name[3] - '0';
120		void __iomem *dsi_reg = cpg->reg +
121			(phy_no ? CPG_DSI1PHYCR : CPG_DSI0PHYCR);
122
123		parent_name = phy_no ? "dsi1pck" : "dsi0pck";
124		mult = __raw_readl(dsi_reg);
125		if (!(mult & 0x8000))
126			mult = 1;
127		else
128			mult = (mult & 0x3f) + 1;
129	} else if (!strcmp(name, "z")) {
130		parent_name = "pll0";
131		table = z_div_table;
132		reg = CPG_FRQCRB;
133		shift = 24;
134		width = 5;
135	} else {
136		const struct div4_clk *c;
137
138		for (c = div4_clks; c->name; c++) {
139			if (!strcmp(name, c->name)) {
140				parent_name = c->parent;
141				table = div4_div_table;
142				reg = c->reg;
143				shift = c->shift;
144				width = 4;
145				break;
146			}
147		}
148		if (!c->name)
149			return ERR_PTR(-EINVAL);
150	}
151
152	if (!table) {
153		return clk_register_fixed_factor(NULL, name, parent_name, 0,
154						 mult, div);
155	} else {
156		return clk_register_divider_table(NULL, name, parent_name, 0,
157						  cpg->reg + reg, shift, width, 0,
158						  table, &cpg->lock);
159	}
160}
161
162static void __init sh73a0_cpg_clocks_init(struct device_node *np)
163{
164	struct sh73a0_cpg *cpg;
165	struct clk **clks;
166	unsigned int i;
167	int num_clks;
168
169	num_clks = of_property_count_strings(np, "clock-output-names");
170	if (num_clks < 0) {
171		pr_err("%s: failed to count clocks\n", __func__);
172		return;
173	}
174
175	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
176	clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
177	if (cpg == NULL || clks == NULL) {
178		/* We're leaking memory on purpose, there's no point in cleaning
179		 * up as the system won't boot anyway.
180		 */
181		return;
182	}
183
184	spin_lock_init(&cpg->lock);
185
186	cpg->data.clks = clks;
187	cpg->data.clk_num = num_clks;
188
189	cpg->reg = of_iomap(np, 0);
190	if (WARN_ON(cpg->reg == NULL))
191		return;
192
193	/* Set SDHI clocks to a known state */
194	writel(0x108, cpg->reg + CPG_SD0CKCR);
195	writel(0x108, cpg->reg + CPG_SD1CKCR);
196	writel(0x108, cpg->reg + CPG_SD2CKCR);
197
198	for (i = 0; i < num_clks; ++i) {
199		const char *name;
200		struct clk *clk;
201
202		of_property_read_string_index(np, "clock-output-names", i,
203					      &name);
204
205		clk = sh73a0_cpg_register_clock(np, cpg, name);
206		if (IS_ERR(clk))
207			pr_err("%s: failed to register %pOFn %s clock (%ld)\n",
208			       __func__, np, name, PTR_ERR(clk));
209		else
210			cpg->data.clks[i] = clk;
211	}
212
213	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
214}
215CLK_OF_DECLARE(sh73a0_cpg_clks, "renesas,sh73a0-cpg-clocks",
216	       sh73a0_cpg_clocks_init);
217