1 /* 2 * Copyright 2011-2012 Calxeda, Inc. 3 * Copyright (C) 2012-2013 Altera Corporation <www.altera.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 * Based from clk-highbank.c 16 * 17 */ 18 #include <linux/clk.h> 19 #include <linux/clkdev.h> 20 #include <linux/clk-provider.h> 21 #include <linux/io.h> 22 #include <linux/of.h> 23 #include <linux/of_address.h> 24 25 #include "clk.h" 26 27 /* Clock bypass bits */ 28 #define MAINPLL_BYPASS (1<<0) 29 #define SDRAMPLL_BYPASS (1<<1) 30 #define SDRAMPLL_SRC_BYPASS (1<<2) 31 #define PERPLL_BYPASS (1<<3) 32 #define PERPLL_SRC_BYPASS (1<<4) 33 34 #define SOCFPGA_PLL_BG_PWRDWN 0 35 #define SOCFPGA_PLL_EXT_ENA 1 36 #define SOCFPGA_PLL_PWR_DOWN 2 37 #define SOCFPGA_PLL_DIVF_MASK 0x0000FFF8 38 #define SOCFPGA_PLL_DIVF_SHIFT 3 39 #define SOCFPGA_PLL_DIVQ_MASK 0x003F0000 40 #define SOCFPGA_PLL_DIVQ_SHIFT 16 41 42 #define CLK_MGR_PLL_CLK_SRC_SHIFT 22 43 #define CLK_MGR_PLL_CLK_SRC_MASK 0x3 44 45 #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw) 46 47 void __iomem *clk_mgr_base_addr; 48 49 static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk, 50 unsigned long parent_rate) 51 { 52 struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk); 53 unsigned long divf, divq, reg; 54 unsigned long long vco_freq; 55 unsigned long bypass; 56 57 reg = readl(socfpgaclk->hw.reg); 58 bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS); 59 if (bypass & MAINPLL_BYPASS) 60 return parent_rate; 61 62 divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT; 63 divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT; 64 vco_freq = (unsigned long long)parent_rate * (divf + 1); 65 do_div(vco_freq, (1 + divq)); 66 return (unsigned long)vco_freq; 67 } 68 69 static u8 clk_pll_get_parent(struct clk_hw *hwclk) 70 { 71 u32 pll_src; 72 struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk); 73 74 pll_src = readl(socfpgaclk->hw.reg); 75 return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) & 76 CLK_MGR_PLL_CLK_SRC_MASK; 77 } 78 79 static struct clk_ops clk_pll_ops = { 80 .recalc_rate = clk_pll_recalc_rate, 81 .get_parent = clk_pll_get_parent, 82 }; 83 84 static __init struct clk *__socfpga_pll_init(struct device_node *node, 85 const struct clk_ops *ops) 86 { 87 u32 reg; 88 struct clk *clk; 89 struct socfpga_pll *pll_clk; 90 const char *clk_name = node->name; 91 const char *parent_name[SOCFPGA_MAX_PARENTS]; 92 struct clk_init_data init; 93 struct device_node *clkmgr_np; 94 int rc; 95 int i = 0; 96 97 of_property_read_u32(node, "reg", ®); 98 99 pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL); 100 if (WARN_ON(!pll_clk)) 101 return NULL; 102 103 clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr"); 104 clk_mgr_base_addr = of_iomap(clkmgr_np, 0); 105 BUG_ON(!clk_mgr_base_addr); 106 pll_clk->hw.reg = clk_mgr_base_addr + reg; 107 108 of_property_read_string(node, "clock-output-names", &clk_name); 109 110 init.name = clk_name; 111 init.ops = ops; 112 init.flags = 0; 113 114 while (i < SOCFPGA_MAX_PARENTS && (parent_name[i] = 115 of_clk_get_parent_name(node, i)) != NULL) 116 i++; 117 118 init.num_parents = i; 119 init.parent_names = parent_name; 120 pll_clk->hw.hw.init = &init; 121 122 pll_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA; 123 clk_pll_ops.enable = clk_gate_ops.enable; 124 clk_pll_ops.disable = clk_gate_ops.disable; 125 126 clk = clk_register(NULL, &pll_clk->hw.hw); 127 if (WARN_ON(IS_ERR(clk))) { 128 kfree(pll_clk); 129 return NULL; 130 } 131 rc = of_clk_add_provider(node, of_clk_src_simple_get, clk); 132 return clk; 133 } 134 135 void __init socfpga_pll_init(struct device_node *node) 136 { 137 __socfpga_pll_init(node, &clk_pll_ops); 138 } 139