1 /*
2 * Copyright (C) 2015 Altera Corporation. All rights reserved
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16 #include <linux/slab.h>
17 #include <linux/clk-provider.h>
18 #include <linux/io.h>
19 #include <linux/of.h>
20 #include <linux/of_address.h>
21
22 #include "clk.h"
23
24 /* Clock Manager offsets */
25 #define CLK_MGR_PLL_CLK_SRC_SHIFT 8
26 #define CLK_MGR_PLL_CLK_SRC_MASK 0x3
27
28 /* Clock bypass bits */
29 #define SOCFPGA_PLL_BG_PWRDWN 0
30 #define SOCFPGA_PLL_PWR_DOWN 1
31 #define SOCFPGA_PLL_EXT_ENA 2
32 #define SOCFPGA_PLL_DIVF_MASK 0x00001FFF
33 #define SOCFPGA_PLL_DIVF_SHIFT 0
34 #define SOCFPGA_PLL_DIVQ_MASK 0x003F0000
35 #define SOCFPGA_PLL_DIVQ_SHIFT 16
36 #define SOCFGPA_MAX_PARENTS 5
37
38 #define SOCFPGA_MAIN_PLL_CLK "main_pll"
39 #define SOCFPGA_PERIP_PLL_CLK "periph_pll"
40
41 #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
42
43 void __iomem *clk_mgr_a10_base_addr;
44
clk_pll_recalc_rate(struct clk_hw * hwclk,unsigned long parent_rate)45 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
46 unsigned long parent_rate)
47 {
48 struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
49 unsigned long divf, divq, reg;
50 unsigned long long vco_freq;
51
52 /* read VCO1 reg for numerator and denominator */
53 reg = readl(socfpgaclk->hw.reg + 0x4);
54 divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
55 divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
56 vco_freq = (unsigned long long)parent_rate * (divf + 1);
57 do_div(vco_freq, (1 + divq));
58 return (unsigned long)vco_freq;
59 }
60
clk_pll_get_parent(struct clk_hw * hwclk)61 static u8 clk_pll_get_parent(struct clk_hw *hwclk)
62 {
63 struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
64 u32 pll_src;
65
66 pll_src = readl(socfpgaclk->hw.reg);
67
68 return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) &
69 CLK_MGR_PLL_CLK_SRC_MASK;
70 }
71
72 static struct clk_ops clk_pll_ops = {
73 .recalc_rate = clk_pll_recalc_rate,
74 .get_parent = clk_pll_get_parent,
75 };
76
__socfpga_pll_init(struct device_node * node,const struct clk_ops * ops)77 static struct clk * __init __socfpga_pll_init(struct device_node *node,
78 const struct clk_ops *ops)
79 {
80 u32 reg;
81 struct clk *clk;
82 struct socfpga_pll *pll_clk;
83 const char *clk_name = node->name;
84 const char *parent_name[SOCFGPA_MAX_PARENTS];
85 struct clk_init_data init;
86 struct device_node *clkmgr_np;
87 int rc;
88 int i = 0;
89
90 of_property_read_u32(node, "reg", ®);
91
92 pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
93 if (WARN_ON(!pll_clk))
94 return NULL;
95
96 clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr");
97 clk_mgr_a10_base_addr = of_iomap(clkmgr_np, 0);
98 of_node_put(clkmgr_np);
99 BUG_ON(!clk_mgr_a10_base_addr);
100 pll_clk->hw.reg = clk_mgr_a10_base_addr + reg;
101
102 of_property_read_string(node, "clock-output-names", &clk_name);
103
104 init.name = clk_name;
105 init.ops = ops;
106 init.flags = 0;
107
108 while (i < SOCFGPA_MAX_PARENTS && (parent_name[i] =
109 of_clk_get_parent_name(node, i)) != NULL)
110 i++;
111 init.num_parents = i;
112 init.parent_names = parent_name;
113 pll_clk->hw.hw.init = &init;
114
115 pll_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
116 clk_pll_ops.enable = clk_gate_ops.enable;
117 clk_pll_ops.disable = clk_gate_ops.disable;
118
119 clk = clk_register(NULL, &pll_clk->hw.hw);
120 if (WARN_ON(IS_ERR(clk))) {
121 kfree(pll_clk);
122 return NULL;
123 }
124 rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
125 return clk;
126 }
127
socfpga_a10_pll_init(struct device_node * node)128 void __init socfpga_a10_pll_init(struct device_node *node)
129 {
130 __socfpga_pll_init(node, &clk_pll_ops);
131 }
132