1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2015 Altera Corporation. All rights reserved 4 */ 5 #include <linux/slab.h> 6 #include <linux/clk-provider.h> 7 #include <linux/io.h> 8 #include <linux/of.h> 9 10 #include "clk.h" 11 12 #define CLK_MGR_FREE_SHIFT 16 13 #define CLK_MGR_FREE_MASK 0x7 14 15 #define SOCFPGA_MPU_FREE_CLK "mpu_free_clk" 16 #define SOCFPGA_NOC_FREE_CLK "noc_free_clk" 17 #define SOCFPGA_SDMMC_FREE_CLK "sdmmc_free_clk" 18 #define to_socfpga_periph_clk(p) container_of(p, struct socfpga_periph_clk, hw.hw) 19 20 static unsigned long clk_periclk_recalc_rate(struct clk_hw *hwclk, 21 unsigned long parent_rate) 22 { 23 struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk); 24 u32 div; 25 26 if (socfpgaclk->fixed_div) { 27 div = socfpgaclk->fixed_div; 28 } else if (socfpgaclk->div_reg) { 29 div = readl(socfpgaclk->div_reg) >> socfpgaclk->shift; 30 div &= GENMASK(socfpgaclk->width - 1, 0); 31 div += 1; 32 } else { 33 div = ((readl(socfpgaclk->hw.reg) & 0x7ff) + 1); 34 } 35 36 return parent_rate / div; 37 } 38 39 static u8 clk_periclk_get_parent(struct clk_hw *hwclk) 40 { 41 struct socfpga_periph_clk *socfpgaclk = to_socfpga_periph_clk(hwclk); 42 u32 clk_src; 43 const char *name = clk_hw_get_name(hwclk); 44 45 clk_src = readl(socfpgaclk->hw.reg); 46 if (streq(name, SOCFPGA_MPU_FREE_CLK) || 47 streq(name, SOCFPGA_NOC_FREE_CLK) || 48 streq(name, SOCFPGA_SDMMC_FREE_CLK)) 49 return (clk_src >> CLK_MGR_FREE_SHIFT) & 50 CLK_MGR_FREE_MASK; 51 else 52 return 0; 53 } 54 55 static const struct clk_ops periclk_ops = { 56 .recalc_rate = clk_periclk_recalc_rate, 57 .get_parent = clk_periclk_get_parent, 58 }; 59 60 static __init void __socfpga_periph_init(struct device_node *node, 61 const struct clk_ops *ops) 62 { 63 u32 reg; 64 struct clk_hw *hw_clk; 65 struct socfpga_periph_clk *periph_clk; 66 const char *clk_name = node->name; 67 const char *parent_name[SOCFPGA_MAX_PARENTS]; 68 struct clk_init_data init; 69 int rc; 70 u32 fixed_div; 71 u32 div_reg[3]; 72 73 of_property_read_u32(node, "reg", ®); 74 75 periph_clk = kzalloc(sizeof(*periph_clk), GFP_KERNEL); 76 if (WARN_ON(!periph_clk)) 77 return; 78 79 periph_clk->hw.reg = clk_mgr_a10_base_addr + reg; 80 81 rc = of_property_read_u32_array(node, "div-reg", div_reg, 3); 82 if (!rc) { 83 periph_clk->div_reg = clk_mgr_a10_base_addr + div_reg[0]; 84 periph_clk->shift = div_reg[1]; 85 periph_clk->width = div_reg[2]; 86 } else { 87 periph_clk->div_reg = NULL; 88 } 89 90 rc = of_property_read_u32(node, "fixed-divider", &fixed_div); 91 if (rc) 92 periph_clk->fixed_div = 0; 93 else 94 periph_clk->fixed_div = fixed_div; 95 96 of_property_read_string(node, "clock-output-names", &clk_name); 97 98 init.name = clk_name; 99 init.ops = ops; 100 init.flags = 0; 101 102 init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS); 103 init.parent_names = parent_name; 104 105 periph_clk->hw.hw.init = &init; 106 107 hw_clk = &periph_clk->hw.hw; 108 109 if (clk_hw_register(NULL, hw_clk)) { 110 kfree(periph_clk); 111 return; 112 } 113 rc = of_clk_add_provider(node, of_clk_src_simple_get, hw_clk); 114 if (rc < 0) { 115 pr_err("Could not register clock provider for node:%s\n", 116 clk_name); 117 goto err_clk; 118 } 119 120 return; 121 122 err_clk: 123 clk_hw_unregister(hw_clk); 124 } 125 126 void __init socfpga_a10_periph_init(struct device_node *node) 127 { 128 __socfpga_periph_init(node, &periclk_ops); 129 } 130