1 /* 2 * rz Core CPG Clocks 3 * 4 * Copyright (C) 2013 Ideas On Board SPRL 5 * Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; version 2 of the License. 10 */ 11 12 #include <linux/clk-provider.h> 13 #include <linux/clk/renesas.h> 14 #include <linux/init.h> 15 #include <linux/kernel.h> 16 #include <linux/of.h> 17 #include <linux/of_address.h> 18 #include <linux/slab.h> 19 20 struct rz_cpg { 21 struct clk_onecell_data data; 22 void __iomem *reg; 23 }; 24 25 #define CPG_FRQCR 0x10 26 #define CPG_FRQCR2 0x14 27 28 #define PPR0 0xFCFE3200 29 #define PIBC0 0xFCFE7000 30 31 #define MD_CLK(x) ((x >> 2) & 1) /* P0_2 */ 32 33 /* ----------------------------------------------------------------------------- 34 * Initialization 35 */ 36 37 static u16 __init rz_cpg_read_mode_pins(void) 38 { 39 void __iomem *ppr0, *pibc0; 40 u16 modes; 41 42 ppr0 = ioremap_nocache(PPR0, 2); 43 pibc0 = ioremap_nocache(PIBC0, 2); 44 BUG_ON(!ppr0 || !pibc0); 45 iowrite16(4, pibc0); /* enable input buffer */ 46 modes = ioread16(ppr0); 47 iounmap(ppr0); 48 iounmap(pibc0); 49 50 return modes; 51 } 52 53 static struct clk * __init 54 rz_cpg_register_clock(struct device_node *np, struct rz_cpg *cpg, const char *name) 55 { 56 u32 val; 57 unsigned mult; 58 static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 }; 59 60 if (strcmp(name, "pll") == 0) { 61 unsigned int cpg_mode = MD_CLK(rz_cpg_read_mode_pins()); 62 const char *parent_name = of_clk_get_parent_name(np, cpg_mode); 63 64 mult = cpg_mode ? (32 / 4) : 30; 65 66 return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, 1); 67 } 68 69 /* If mapping regs failed, skip non-pll clocks. System will boot anyhow */ 70 if (!cpg->reg) 71 return ERR_PTR(-ENXIO); 72 73 /* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. 2/3) 74 * and the constraint that always g <= i. To get the rz platform started, 75 * let them run at fixed current speed and implement the details later. 76 */ 77 if (strcmp(name, "i") == 0) 78 val = (clk_readl(cpg->reg + CPG_FRQCR) >> 8) & 3; 79 else if (strcmp(name, "g") == 0) 80 val = clk_readl(cpg->reg + CPG_FRQCR2) & 3; 81 else 82 return ERR_PTR(-EINVAL); 83 84 mult = frqcr_tab[val]; 85 return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3); 86 } 87 88 static void __init rz_cpg_clocks_init(struct device_node *np) 89 { 90 struct rz_cpg *cpg; 91 struct clk **clks; 92 unsigned i; 93 int num_clks; 94 95 num_clks = of_property_count_strings(np, "clock-output-names"); 96 if (WARN(num_clks <= 0, "can't count CPG clocks\n")) 97 return; 98 99 cpg = kzalloc(sizeof(*cpg), GFP_KERNEL); 100 clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL); 101 BUG_ON(!cpg || !clks); 102 103 cpg->data.clks = clks; 104 cpg->data.clk_num = num_clks; 105 106 cpg->reg = of_iomap(np, 0); 107 108 for (i = 0; i < num_clks; ++i) { 109 const char *name; 110 struct clk *clk; 111 112 of_property_read_string_index(np, "clock-output-names", i, &name); 113 114 clk = rz_cpg_register_clock(np, cpg, name); 115 if (IS_ERR(clk)) 116 pr_err("%s: failed to register %s %s clock (%ld)\n", 117 __func__, np->name, name, PTR_ERR(clk)); 118 else 119 cpg->data.clks[i] = clk; 120 } 121 122 of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data); 123 124 cpg_mstp_add_clk_domain(np); 125 } 126 CLK_OF_DECLARE(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init); 127