kernel/drivers/clk/shmobile/clk-r8a7740.c

   1 /*
   2  * r8a7740 Core CPG Clocks
   3  *
   4  * Copyright (C) 2014  Ulrich Hecht
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  */
  10
  11 #include <linux/clk-provider.h>
  12 #include <linux/clkdev.h>
  13 #include <linux/clk/shmobile.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/spinlock.h>
  19
  20 struct r8a7740_cpg {
  21         struct clk_onecell_data data;
  22         spinlock_t lock;
  23         void __iomem *reg;
  24 };
  25
  26 #define CPG_FRQCRA      0x00
  27 #define CPG_FRQCRB      0x04
  28 #define CPG_PLLC2CR     0x2c
  29 #define CPG_USBCKCR     0x8c
  30 #define CPG_FRQCRC      0xe0
  31
  32 #define CLK_ENABLE_ON_INIT BIT(0)
  33
  34 struct div4_clk {
  35         const char *name;
  36         unsigned int reg;
  37         unsigned int shift;
  38         int flags;
  39 };
  40
  41 static struct div4_clk div4_clks[] = {
  42         { "i", CPG_FRQCRA, 20, CLK_ENABLE_ON_INIT },
  43         { "zg", CPG_FRQCRA, 16, CLK_ENABLE_ON_INIT },
  44         { "b", CPG_FRQCRA,  8, CLK_ENABLE_ON_INIT },
  45         { "m1", CPG_FRQCRA,  4, CLK_ENABLE_ON_INIT },
  46         { "hp", CPG_FRQCRB,  4, 0 },
  47         { "hpp", CPG_FRQCRC, 20, 0 },
  48         { "usbp", CPG_FRQCRC, 16, 0 },
  49         { "s", CPG_FRQCRC, 12, 0 },
  50         { "zb", CPG_FRQCRC,  8, 0 },
  51         { "m3", CPG_FRQCRC,  4, 0 },
  52         { "cp", CPG_FRQCRC,  0, 0 },
  53         { NULL, 0, 0, 0 },
  54 };
  55
  56 static const struct clk_div_table div4_div_table[] = {
  57         { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
  58         { 6, 16 }, { 7, 18 }, { 8, 24 }, { 9, 32 }, { 10, 36 }, { 11, 48 },
  59         { 13, 72 }, { 14, 96 }, { 0, 0 }
  60 };
  61
  62 static u32 cpg_mode __initdata;
  63
  64 static struct clk * __init
  65 r8a7740_cpg_register_clock(struct device_node *np, struct r8a7740_cpg *cpg,
  66                              const char *name)
  67 {
  68         const struct clk_div_table *table = NULL;
  69         const char *parent_name;
  70         unsigned int shift, reg;
  71         unsigned int mult = 1;
  72         unsigned int div = 1;
  73
  74         if (!strcmp(name, "r")) {
  75                 switch (cpg_mode & (BIT(2) | BIT(1))) {
  76                 case BIT(1) | BIT(2):
  77                         /* extal1 */
  78                         parent_name = of_clk_get_parent_name(np, 0);
  79                         div = 2048;
  80                         break;
  81                 case BIT(2):
  82                         /* extal1 */
  83                         parent_name = of_clk_get_parent_name(np, 0);
  84                         div = 1024;
  85                         break;
  86                 default:
  87                         /* extalr */
  88                         parent_name = of_clk_get_parent_name(np, 2);
  89                         break;
  90                 }
  91         } else if (!strcmp(name, "system")) {
  92                 parent_name = of_clk_get_parent_name(np, 0);
  93                 if (cpg_mode & BIT(1))
  94                         div = 2;
  95         } else if (!strcmp(name, "pllc0")) {
  96                 /* PLLC0/1 are configurable multiplier clocks. Register them as
  97                  * fixed factor clocks for now as there's no generic multiplier
  98                  * clock implementation and we currently have no need to change
  99                  * the multiplier value.
 100                  */
 101                 u32 value = clk_readl(cpg->reg + CPG_FRQCRC);
 102                 parent_name = "system";
 103                 mult = ((value >> 24) & 0x7f) + 1;
 104         } else if (!strcmp(name, "pllc1")) {
 105                 u32 value = clk_readl(cpg->reg + CPG_FRQCRA);
 106                 parent_name = "system";
 107                 mult = ((value >> 24) & 0x7f) + 1;
 108                 div = 2;
 109         } else if (!strcmp(name, "pllc2")) {
 110                 u32 value = clk_readl(cpg->reg + CPG_PLLC2CR);
 111                 parent_name = "system";
 112                 mult = ((value >> 24) & 0x3f) + 1;
 113         } else if (!strcmp(name, "usb24s")) {
 114                 u32 value = clk_readl(cpg->reg + CPG_USBCKCR);
 115                 if (value & BIT(7))
 116                         /* extal2 */
 117                         parent_name = of_clk_get_parent_name(np, 1);
 118                 else
 119                         parent_name = "system";
 120                 if (!(value & BIT(6)))
 121                         div = 2;
 122         } else {
 123                 struct div4_clk *c;
 124                 for (c = div4_clks; c->name; c++) {
 125                         if (!strcmp(name, c->name)) {
 126                                 parent_name = "pllc1";
 127                                 table = div4_div_table;
 128                                 reg = c->reg;
 129                                 shift = c->shift;
 130                                 break;
 131                         }
 132                 }
 133                 if (!c->name)
 134                         return ERR_PTR(-EINVAL);
 135         }
 136
 137         if (!table) {
 138                 return clk_register_fixed_factor(NULL, name, parent_name, 0,
 139                                                  mult, div);
 140         } else {
 141                 return clk_register_divider_table(NULL, name, parent_name, 0,
 142                                                   cpg->reg + reg, shift, 4, 0,
 143                                                   table, &cpg->lock);
 144         }
 145 }
 146
 147 static void __init r8a7740_cpg_clocks_init(struct device_node *np)
 148 {
 149         struct r8a7740_cpg *cpg;
 150         struct clk **clks;
 151         unsigned int i;
 152         int num_clks;
 153
 154         if (of_property_read_u32(np, "renesas,mode", &cpg_mode))
 155                 pr_warn("%s: missing renesas,mode property\n", __func__);
 156
 157         num_clks = of_property_count_strings(np, "clock-output-names");
 158         if (num_clks < 0) {
 159                 pr_err("%s: failed to count clocks\n", __func__);
 160                 return;
 161         }
 162
 163         cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
 164         clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
 165         if (cpg == NULL || clks == NULL) {
 166                 /* We're leaking memory on purpose, there's no point in cleaning
 167                  * up as the system won't boot anyway.
 168                  */
 169                 return;
 170         }
 171
 172         spin_lock_init(&cpg->lock);
 173
 174         cpg->data.clks = clks;
 175         cpg->data.clk_num = num_clks;
 176
 177         cpg->reg = of_iomap(np, 0);
 178         if (WARN_ON(cpg->reg == NULL))
 179                 return;
 180
 181         for (i = 0; i < num_clks; ++i) {
 182                 const char *name;
 183                 struct clk *clk;
 184
 185                 of_property_read_string_index(np, "clock-output-names", i,
 186                                               &name);
 187
 188                 clk = r8a7740_cpg_register_clock(np, cpg, name);
 189                 if (IS_ERR(clk))
 190                         pr_err("%s: failed to register %s %s clock (%ld)\n",
 191                                __func__, np->name, name, PTR_ERR(clk));
 192                 else
 193                         cpg->data.clks[i] = clk;
 194         }
 195
 196         of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
 197 }
 198 CLK_OF_DECLARE(r8a7740_cpg_clks, "renesas,r8a7740-cpg-clocks",
 199                r8a7740_cpg_clocks_init);