xref: /openbmc/linux/drivers/clk/rockchip/clk-ddr.c (revision b7019ac5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2016 Rockchip Electronics Co. Ltd.
4  * Author: Lin Huang <hl@rock-chips.com>
5  */
6 
7 #include <linux/arm-smccc.h>
8 #include <linux/clk.h>
9 #include <linux/clk-provider.h>
10 #include <linux/io.h>
11 #include <linux/slab.h>
12 #include <soc/rockchip/rockchip_sip.h>
13 #include "clk.h"
14 
15 struct rockchip_ddrclk {
16 	struct clk_hw	hw;
17 	void __iomem	*reg_base;
18 	int		mux_offset;
19 	int		mux_shift;
20 	int		mux_width;
21 	int		div_shift;
22 	int		div_width;
23 	int		ddr_flag;
24 	spinlock_t	*lock;
25 };
26 
27 #define to_rockchip_ddrclk_hw(hw) container_of(hw, struct rockchip_ddrclk, hw)
28 
29 static int rockchip_ddrclk_sip_set_rate(struct clk_hw *hw, unsigned long drate,
30 					unsigned long prate)
31 {
32 	struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
33 	unsigned long flags;
34 	struct arm_smccc_res res;
35 
36 	spin_lock_irqsave(ddrclk->lock, flags);
37 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, drate, 0,
38 		      ROCKCHIP_SIP_CONFIG_DRAM_SET_RATE,
39 		      0, 0, 0, 0, &res);
40 	spin_unlock_irqrestore(ddrclk->lock, flags);
41 
42 	return res.a0;
43 }
44 
45 static unsigned long
46 rockchip_ddrclk_sip_recalc_rate(struct clk_hw *hw,
47 				unsigned long parent_rate)
48 {
49 	struct arm_smccc_res res;
50 
51 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
52 		      ROCKCHIP_SIP_CONFIG_DRAM_GET_RATE,
53 		      0, 0, 0, 0, &res);
54 
55 	return res.a0;
56 }
57 
58 static long rockchip_ddrclk_sip_round_rate(struct clk_hw *hw,
59 					   unsigned long rate,
60 					   unsigned long *prate)
61 {
62 	struct arm_smccc_res res;
63 
64 	arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, rate, 0,
65 		      ROCKCHIP_SIP_CONFIG_DRAM_ROUND_RATE,
66 		      0, 0, 0, 0, &res);
67 
68 	return res.a0;
69 }
70 
71 static u8 rockchip_ddrclk_get_parent(struct clk_hw *hw)
72 {
73 	struct rockchip_ddrclk *ddrclk = to_rockchip_ddrclk_hw(hw);
74 	u32 val;
75 
76 	val = readl(ddrclk->reg_base +
77 			ddrclk->mux_offset) >> ddrclk->mux_shift;
78 	val &= GENMASK(ddrclk->mux_width - 1, 0);
79 
80 	return val;
81 }
82 
83 static const struct clk_ops rockchip_ddrclk_sip_ops = {
84 	.recalc_rate = rockchip_ddrclk_sip_recalc_rate,
85 	.set_rate = rockchip_ddrclk_sip_set_rate,
86 	.round_rate = rockchip_ddrclk_sip_round_rate,
87 	.get_parent = rockchip_ddrclk_get_parent,
88 };
89 
90 struct clk *rockchip_clk_register_ddrclk(const char *name, int flags,
91 					 const char *const *parent_names,
92 					 u8 num_parents, int mux_offset,
93 					 int mux_shift, int mux_width,
94 					 int div_shift, int div_width,
95 					 int ddr_flag, void __iomem *reg_base,
96 					 spinlock_t *lock)
97 {
98 	struct rockchip_ddrclk *ddrclk;
99 	struct clk_init_data init;
100 	struct clk *clk;
101 
102 	ddrclk = kzalloc(sizeof(*ddrclk), GFP_KERNEL);
103 	if (!ddrclk)
104 		return ERR_PTR(-ENOMEM);
105 
106 	init.name = name;
107 	init.parent_names = parent_names;
108 	init.num_parents = num_parents;
109 
110 	init.flags = flags;
111 	init.flags |= CLK_SET_RATE_NO_REPARENT;
112 
113 	switch (ddr_flag) {
114 	case ROCKCHIP_DDRCLK_SIP:
115 		init.ops = &rockchip_ddrclk_sip_ops;
116 		break;
117 	default:
118 		pr_err("%s: unsupported ddrclk type %d\n", __func__, ddr_flag);
119 		kfree(ddrclk);
120 		return ERR_PTR(-EINVAL);
121 	}
122 
123 	ddrclk->reg_base = reg_base;
124 	ddrclk->lock = lock;
125 	ddrclk->hw.init = &init;
126 	ddrclk->mux_offset = mux_offset;
127 	ddrclk->mux_shift = mux_shift;
128 	ddrclk->mux_width = mux_width;
129 	ddrclk->div_shift = div_shift;
130 	ddrclk->div_width = div_width;
131 	ddrclk->ddr_flag = ddr_flag;
132 
133 	clk = clk_register(NULL, &ddrclk->hw);
134 	if (IS_ERR(clk))
135 		kfree(ddrclk);
136 
137 	return clk;
138 }
139