xref: /linux/drivers/clk/rockchip/clk-ddr.c (revision 6f52b16c5b29b89d92c0e7236f4655dc8491ad70)
1 /*
2  * Copyright (c) 2016 Rockchip Electronics Co. Ltd.
3  * Author: Lin Huang <hl@rock-chips.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  */
15 
16 #include <linux/arm-smccc.h>
17 #include <linux/clk.h>
18 #include <linux/clk-provider.h>
19 #include <linux/io.h>
20 #include <linux/slab.h>
21 #include <soc/rockchip/rockchip_sip.h>
22 #include "clk.h"
23 
24 struct rockchip_ddrclk {
25 	struct clk_hw	hw;
26 	void __iomem	*reg_base;
27 	int		mux_offset;
28 	int		mux_shift;
29 	int		mux_width;
30 	int		div_shift;
31 	int		div_width;
32 	int		ddr_flag;
33 	spinlock_t	*lock;
34 };
35 
36 #define to_rockchip_ddrclk_hw(hw) container_of(hw, struct rockchip_ddrclk, hw)
37 
38 static int rockchip_ddrclk_sip_set_rate(struct clk_hw *hw, unsigned long drate,
39 					unsigned long prate)
40 {
41 	struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
42 	unsigned long flags;
43 	struct arm_smccc_res res;
44 
45 	spin_lock_irqsave(ddrclk->lock, flags);
46 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, drate, 0,
47 		      ROCKCHIP_SIP_CONFIG_DRAM_SET_RATE,
48 		      0, 0, 0, 0, &res);
49 	spin_unlock_irqrestore(ddrclk->lock, flags);
50 
51 	return res.a0;
52 }
53 
54 static unsigned long
55 rockchip_ddrclk_sip_recalc_rate(struct clk_hw *hw,
56 				unsigned long parent_rate)
57 {
58 	struct arm_smccc_res res;
59 
60 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
61 		      ROCKCHIP_SIP_CONFIG_DRAM_GET_RATE,
62 		      0, 0, 0, 0, &res);
63 
64 	return res.a0;
65 }
66 
67 static long rockchip_ddrclk_sip_round_rate(struct clk_hw *hw,
68 					   unsigned long rate,
69 					   unsigned long *prate)
70 {
71 	struct arm_smccc_res res;
72 
73 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, rate, 0,
74 		      ROCKCHIP_SIP_CONFIG_DRAM_ROUND_RATE,
75 		      0, 0, 0, 0, &res);
76 
77 	return res.a0;
78 }
79 
80 static u8 rockchip_ddrclk_get_parent(struct clk_hw *hw)
81 {
82 	struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
83 	int num_parents = clk_hw_get_num_parents(hw);
84 	u32 val;
85 
86 	val = clk_readl(ddrclk->reg_base +
87 			ddrclk->mux_offset) >> ddrclk->mux_shift;
88 	val &= GENMASK(ddrclk->mux_width - 1, 0);
89 
90 	if (val >= num_parents)
91 		return -EINVAL;
92 
93 	return val;
94 }
95 
96 static const struct clk_ops rockchip_ddrclk_sip_ops = {
97 	.recalc_rate = rockchip_ddrclk_sip_recalc_rate,
98 	.set_rate = rockchip_ddrclk_sip_set_rate,
99 	.round_rate = rockchip_ddrclk_sip_round_rate,
100 	.get_parent = rockchip_ddrclk_get_parent,
101 };
102 
103 struct clk *rockchip_clk_register_ddrclk(const char *name, int flags,
104 					 const char *const *parent_names,
105 					 u8 num_parents, int mux_offset,
106 					 int mux_shift, int mux_width,
107 					 int div_shift, int div_width,
108 					 int ddr_flag, void __iomem *reg_base,
109 					 spinlock_t *lock)
110 {
111 	struct rockchip_ddrclk *ddrclk;
112 	struct clk_init_data init;
113 	struct clk *clk;
114 
115 	ddrclk = kzalloc(sizeof(*ddrclk), GFP_KERNEL);
116 	if (!ddrclk)
117 		return ERR_PTR(-ENOMEM);
118 
119 	init.name = name;
120 	init.parent_names = parent_names;
121 	init.num_parents = num_parents;
122 
123 	init.flags = flags;
124 	init.flags |= CLK_SET_RATE_NO_REPARENT;
125 
126 	switch (ddr_flag) {
127 	case ROCKCHIP_DDRCLK_SIP:
128 		init.ops = &rockchip_ddrclk_sip_ops;
129 		break;
130 	default:
131 		pr_err("%s: unsupported ddrclk type %d\n", __func__, ddr_flag);
132 		kfree(ddrclk);
133 		return ERR_PTR(-EINVAL);
134 	}
135 
136 	ddrclk->reg_base = reg_base;
137 	ddrclk->lock = lock;
138 	ddrclk->hw.init = &init;
139 	ddrclk->mux_offset = mux_offset;
140 	ddrclk->mux_shift = mux_shift;
141 	ddrclk->mux_width = mux_width;
142 	ddrclk->div_shift = div_shift;
143 	ddrclk->div_width = div_width;
144 	ddrclk->ddr_flag = ddr_flag;
145 
146 	clk = clk_register(NULL, &ddrclk->hw);
147 	if (IS_ERR(clk))
148 		kfree(ddrclk);
149 
150 	return clk;
151 }
152