1/*
2 * sh73a0 Core CPG Clocks
3 *
4 * Copyright (C) 2014  Ulrich Hecht
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 */
10
11#include <linux/clk-provider.h>
12#include <linux/clkdev.h>
13#include <linux/clk/shmobile.h>
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/of.h>
17#include <linux/of_address.h>
18#include <linux/spinlock.h>
19
20struct sh73a0_cpg {
21	struct clk_onecell_data data;
22	spinlock_t lock;
23	void __iomem *reg;
24};
25
26#define CPG_FRQCRA	0x00
27#define CPG_FRQCRB	0x04
28#define CPG_SD0CKCR	0x74
29#define CPG_SD1CKCR	0x78
30#define CPG_SD2CKCR	0x7c
31#define CPG_PLLECR	0xd0
32#define CPG_PLL0CR	0xd8
33#define CPG_PLL1CR	0x28
34#define CPG_PLL2CR	0x2c
35#define CPG_PLL3CR	0xdc
36#define CPG_CKSCR	0xc0
37#define CPG_DSI0PHYCR	0x6c
38#define CPG_DSI1PHYCR	0x70
39
40#define CLK_ENABLE_ON_INIT BIT(0)
41
42struct div4_clk {
43	const char *name;
44	const char *parent;
45	unsigned int reg;
46	unsigned int shift;
47};
48
49static struct div4_clk div4_clks[] = {
50	{ "zg", "pll0", CPG_FRQCRA, 16 },
51	{ "m3", "pll1", CPG_FRQCRA, 12 },
52	{ "b",  "pll1", CPG_FRQCRA,  8 },
53	{ "m1", "pll1", CPG_FRQCRA,  4 },
54	{ "m2", "pll1", CPG_FRQCRA,  0 },
55	{ "zx", "pll1", CPG_FRQCRB, 12 },
56	{ "hp", "pll1", CPG_FRQCRB,  4 },
57	{ NULL, NULL, 0, 0 },
58};
59
60static const struct clk_div_table div4_div_table[] = {
61	{ 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
62	{ 6, 16 }, { 7, 18 }, { 8, 24 }, { 10, 36 }, { 11, 48 },
63	{ 12, 7 }, { 0, 0 }
64};
65
66static const struct clk_div_table z_div_table[] = {
67	/* ZSEL == 0 */
68	{ 0, 1 }, { 1, 1 }, { 2, 1 }, { 3, 1 }, { 4, 1 }, { 5, 1 },
69	{ 6, 1 }, { 7, 1 }, { 8, 1 }, { 9, 1 }, { 10, 1 }, { 11, 1 },
70	{ 12, 1 }, { 13, 1 }, { 14, 1 }, { 15, 1 },
71	/* ZSEL == 1 */
72	{ 16, 2 }, { 17, 3 }, { 18, 4 }, { 19, 6 }, { 20, 8 }, { 21, 12 },
73	{ 22, 16 }, { 24, 24 }, { 27, 48 }, { 0, 0 }
74};
75
76static struct clk * __init
77sh73a0_cpg_register_clock(struct device_node *np, struct sh73a0_cpg *cpg,
78			     const char *name)
79{
80	const struct clk_div_table *table = NULL;
81	unsigned int shift, reg, width;
82	const char *parent_name;
83	unsigned int mult = 1;
84	unsigned int div = 1;
85
86	if (!strcmp(name, "main")) {
87		/* extal1, extal1_div2, extal2, extal2_div2 */
88		u32 parent_idx = (clk_readl(cpg->reg + CPG_CKSCR) >> 28) & 3;
89
90		parent_name = of_clk_get_parent_name(np, parent_idx >> 1);
91		div = (parent_idx & 1) + 1;
92	} else if (!strncmp(name, "pll", 3)) {
93		void __iomem *enable_reg = cpg->reg;
94		u32 enable_bit = name[3] - '0';
95
96		parent_name = "main";
97		switch (enable_bit) {
98		case 0:
99			enable_reg += CPG_PLL0CR;
100			break;
101		case 1:
102			enable_reg += CPG_PLL1CR;
103			break;
104		case 2:
105			enable_reg += CPG_PLL2CR;
106			break;
107		case 3:
108			enable_reg += CPG_PLL3CR;
109			break;
110		default:
111			return ERR_PTR(-EINVAL);
112		}
113		if (clk_readl(cpg->reg + CPG_PLLECR) & BIT(enable_bit)) {
114			mult = ((clk_readl(enable_reg) >> 24) & 0x3f) + 1;
115			/* handle CFG bit for PLL1 and PLL2 */
116			if (enable_bit == 1 || enable_bit == 2)
117				if (clk_readl(enable_reg) & BIT(20))
118					mult *= 2;
119		}
120	} else if (!strcmp(name, "dsi0phy") || !strcmp(name, "dsi1phy")) {
121		u32 phy_no = name[3] - '0';
122		void __iomem *dsi_reg = cpg->reg +
123			(phy_no ? CPG_DSI1PHYCR : CPG_DSI0PHYCR);
124
125		parent_name = phy_no ? "dsi1pck" : "dsi0pck";
126		mult = __raw_readl(dsi_reg);
127		if (!(mult & 0x8000))
128			mult = 1;
129		else
130			mult = (mult & 0x3f) + 1;
131	} else if (!strcmp(name, "z")) {
132		parent_name = "pll0";
133		table = z_div_table;
134		reg = CPG_FRQCRB;
135		shift = 24;
136		width = 5;
137	} else {
138		struct div4_clk *c;
139
140		for (c = div4_clks; c->name; c++) {
141			if (!strcmp(name, c->name)) {
142				parent_name = c->parent;
143				table = div4_div_table;
144				reg = c->reg;
145				shift = c->shift;
146				width = 4;
147				break;
148			}
149		}
150		if (!c->name)
151			return ERR_PTR(-EINVAL);
152	}
153
154	if (!table) {
155		return clk_register_fixed_factor(NULL, name, parent_name, 0,
156						 mult, div);
157	} else {
158		return clk_register_divider_table(NULL, name, parent_name, 0,
159						  cpg->reg + reg, shift, width, 0,
160						  table, &cpg->lock);
161	}
162}
163
164static void __init sh73a0_cpg_clocks_init(struct device_node *np)
165{
166	struct sh73a0_cpg *cpg;
167	struct clk **clks;
168	unsigned int i;
169	int num_clks;
170
171	num_clks = of_property_count_strings(np, "clock-output-names");
172	if (num_clks < 0) {
173		pr_err("%s: failed to count clocks\n", __func__);
174		return;
175	}
176
177	cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
178	clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
179	if (cpg == NULL || clks == NULL) {
180		/* We're leaking memory on purpose, there's no point in cleaning
181		 * up as the system won't boot anyway.
182		 */
183		return;
184	}
185
186	spin_lock_init(&cpg->lock);
187
188	cpg->data.clks = clks;
189	cpg->data.clk_num = num_clks;
190
191	cpg->reg = of_iomap(np, 0);
192	if (WARN_ON(cpg->reg == NULL))
193		return;
194
195	/* Set SDHI clocks to a known state */
196	clk_writel(0x108, cpg->reg + CPG_SD0CKCR);
197	clk_writel(0x108, cpg->reg + CPG_SD1CKCR);
198	clk_writel(0x108, cpg->reg + CPG_SD2CKCR);
199
200	for (i = 0; i < num_clks; ++i) {
201		const char *name;
202		struct clk *clk;
203
204		of_property_read_string_index(np, "clock-output-names", i,
205					      &name);
206
207		clk = sh73a0_cpg_register_clock(np, cpg, name);
208		if (IS_ERR(clk))
209			pr_err("%s: failed to register %s %s clock (%ld)\n",
210			       __func__, np->name, name, PTR_ERR(clk));
211		else
212			cpg->data.clks[i] = clk;
213	}
214
215	of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
216}
217CLK_OF_DECLARE(sh73a0_cpg_clks, "renesas,sh73a0-cpg-clocks",
218	       sh73a0_cpg_clocks_init);
219