xref: /openbmc/linux/drivers/clk/rockchip/clk-ddr.c (revision ae213c44)
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 	u32 val;
84 
85 	val = readl(ddrclk->reg_base +
86 			ddrclk->mux_offset) >> ddrclk->mux_shift;
87 	val &= GENMASK(ddrclk->mux_width - 1, 0);
88 
89 	return val;
90 }
91 
92 static const struct clk_ops rockchip_ddrclk_sip_ops = {
93 	.recalc_rate = rockchip_ddrclk_sip_recalc_rate,
94 	.set_rate = rockchip_ddrclk_sip_set_rate,
95 	.round_rate = rockchip_ddrclk_sip_round_rate,
96 	.get_parent = rockchip_ddrclk_get_parent,
97 };
98 
99 struct clk *rockchip_clk_register_ddrclk(const char *name, int flags,
100 					 const char *const *parent_names,
101 					 u8 num_parents, int mux_offset,
102 					 int mux_shift, int mux_width,
103 					 int div_shift, int div_width,
104 					 int ddr_flag, void __iomem *reg_base,
105 					 spinlock_t *lock)
106 {
107 	struct rockchip_ddrclk *ddrclk;
108 	struct clk_init_data init;
109 	struct clk *clk;
110 
111 	ddrclk = kzalloc(sizeof(*ddrclk), GFP_KERNEL);
112 	if (!ddrclk)
113 		return ERR_PTR(-ENOMEM);
114 
115 	init.name = name;
116 	init.parent_names = parent_names;
117 	init.num_parents = num_parents;
118 
119 	init.flags = flags;
120 	init.flags |= CLK_SET_RATE_NO_REPARENT;
121 
122 	switch (ddr_flag) {
123 	case ROCKCHIP_DDRCLK_SIP:
124 		init.ops = &rockchip_ddrclk_sip_ops;
125 		break;
126 	default:
127 		pr_err("%s: unsupported ddrclk type %d\n", __func__, ddr_flag);
128 		kfree(ddrclk);
129 		return ERR_PTR(-EINVAL);
130 	}
131 
132 	ddrclk->reg_base = reg_base;
133 	ddrclk->lock = lock;
134 	ddrclk->hw.init = &init;
135 	ddrclk->mux_offset = mux_offset;
136 	ddrclk->mux_shift = mux_shift;
137 	ddrclk->mux_width = mux_width;
138 	ddrclk->div_shift = div_shift;
139 	ddrclk->div_width = div_width;
140 	ddrclk->ddr_flag = ddr_flag;
141 
142 	clk = clk_register(NULL, &ddrclk->hw);
143 	if (IS_ERR(clk))
144 		kfree(ddrclk);
145 
146 	return clk;
147 }
148