aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/clk/baikal-t1/clk-ccu-pll.c
blob: 1eec8c0b8f50fcdaf95ade7545715195e5cee580 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
 *
 * Authors:
 *   Serge Semin <Sergey.Semin@baikalelectronics.ru>
 *   Dmitry Dunaev <dmitry.dunaev@baikalelectronics.ru>
 *
 * Baikal-T1 CCU PLL clocks driver
 */

#define pr_fmt(fmt) "bt1-ccu-pll: " fmt

#include <linux/kernel.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/clk-provider.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/ioport.h>
#include <linux/regmap.h>

#include <dt-bindings/clock/bt1-ccu.h>

#include "ccu-pll.h"

#define CCU_CPU_PLL_BASE		0x000
#define CCU_SATA_PLL_BASE		0x008
#define CCU_DDR_PLL_BASE		0x010
#define CCU_PCIE_PLL_BASE		0x018
#define CCU_ETH_PLL_BASE		0x020

#define CCU_PLL_INFO(_id, _name, _pname, _base, _flags)	\
	{						\
		.id = _id,				\
		.name = _name,				\
		.parent_name = _pname,			\
		.base = _base,				\
		.flags = _flags				\
	}

#define CCU_PLL_NUM			ARRAY_SIZE(pll_info)

struct ccu_pll_info {
	unsigned int id;
	const char *name;
	const char *parent_name;
	unsigned int base;
	unsigned long flags;
};

/*
 * Mark as critical all PLLs except Ethernet one. CPU and DDR PLLs are sources
 * of CPU cores and DDR controller reference clocks, due to which they
 * obviously shouldn't be ever gated. SATA and PCIe PLLs are the parents of
 * APB-bus and DDR controller AXI-bus clocks. If they are gated the system will
 * be unusable.
 */
static const struct ccu_pll_info pll_info[] = {
	CCU_PLL_INFO(CCU_CPU_PLL, "cpu_pll", "ref_clk", CCU_CPU_PLL_BASE,
		     CLK_IS_CRITICAL),
	CCU_PLL_INFO(CCU_SATA_PLL, "sata_pll", "ref_clk", CCU_SATA_PLL_BASE,
		     CLK_IS_CRITICAL | CLK_SET_RATE_GATE),
	CCU_PLL_INFO(CCU_DDR_PLL, "ddr_pll", "ref_clk", CCU_DDR_PLL_BASE,
		     CLK_IS_CRITICAL | CLK_SET_RATE_GATE),
	CCU_PLL_INFO(CCU_PCIE_PLL, "pcie_pll", "ref_clk", CCU_PCIE_PLL_BASE,
		     CLK_IS_CRITICAL),
	CCU_PLL_INFO(CCU_ETH_PLL, "eth_pll", "ref_clk", CCU_ETH_PLL_BASE,
		     CLK_SET_RATE_GATE)
};

struct ccu_pll_data {
	struct device_node *np;
	struct regmap *sys_regs;
	struct ccu_pll *plls[CCU_PLL_NUM];
};

static struct ccu_pll *ccu_pll_find_desc(struct ccu_pll_data *data,
					 unsigned int clk_id)
{
	struct ccu_pll *pll;
	int idx;

	for (idx = 0; idx < CCU_PLL_NUM; ++idx) {
		pll = data->plls[idx];
		if (pll && pll->id == clk_id)
			return pll;
	}

	return ERR_PTR(-EINVAL);
}

static struct ccu_pll_data *ccu_pll_create_data(struct device_node *np)
{
	struct ccu_pll_data *data;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
		return ERR_PTR(-ENOMEM);

	data->np = np;

	return data;
}

static void ccu_pll_free_data(struct ccu_pll_data *data)
{
	kfree(data);
}

static int ccu_pll_find_sys_regs(struct ccu_pll_data *data)
{
	data->sys_regs = syscon_node_to_regmap(data->np->parent);
	if (IS_ERR(data->sys_regs)) {
		pr_err("Failed to find syscon regs for '%s'\n",
			of_node_full_name(data->np));
		return PTR_ERR(data->sys_regs);
	}

	return 0;
}

static struct clk_hw *ccu_pll_of_clk_hw_get(struct of_phandle_args *clkspec,
					    void *priv)
{
	struct ccu_pll_data *data = priv;
	struct ccu_pll *pll;
	unsigned int clk_id;

	clk_id = clkspec->args[0];
	pll = ccu_pll_find_desc(data, clk_id);
	if (IS_ERR(pll)) {
		pr_info("Invalid PLL clock ID %d specified\n", clk_id);
		return ERR_CAST(pll);
	}

	return ccu_pll_get_clk_hw(pll);
}

static int ccu_pll_clk_register(struct ccu_pll_data *data)
{
	int idx, ret;

	for (idx = 0; idx < CCU_PLL_NUM; ++idx) {
		const struct ccu_pll_info *info = &pll_info[idx];
		struct ccu_pll_init_data init = {0};

		init.id = info->id;
		init.name = info->name;
		init.parent_name = info->parent_name;
		init.base = info->base;
		init.sys_regs = data->sys_regs;
		init.np = data->np;
		init.flags = info->flags;

		data->plls[idx] = ccu_pll_hw_register(&init);
		if (IS_ERR(data->plls[idx])) {
			ret = PTR_ERR(data->plls[idx]);
			pr_err("Couldn't register PLL hw '%s'\n",
				init.name);
			goto err_hw_unregister;
		}
	}

	ret = of_clk_add_hw_provider(data->np, ccu_pll_of_clk_hw_get, data);
	if (ret) {
		pr_err("Couldn't register PLL provider of '%s'\n",
			of_node_full_name(data->np));
		goto err_hw_unregister;
	}

	return 0;

err_hw_unregister:
	for (--idx; idx >= 0; --idx)
		ccu_pll_hw_unregister(data->plls[idx]);

	return ret;
}

static __init void ccu_pll_init(struct device_node *np)
{
	struct ccu_pll_data *data;
	int ret;

	data = ccu_pll_create_data(np);
	if (IS_ERR(data))
		return;

	ret = ccu_pll_find_sys_regs(data);
	if (ret)
		goto err_free_data;

	ret = ccu_pll_clk_register(data);
	if (ret)
		goto err_free_data;

	return;

err_free_data:
	ccu_pll_free_data(data);
}
CLK_OF_DECLARE(ccu_pll, "baikal,bt1-ccu-pll", ccu_pll_init);