drivers/clk/renesas/clk-r8a7740.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * r8a7740 Core CPG Clocks
   4  *
   5  * Copyright (C) 2014  Ulrich Hecht
   6  */
   7
   8 #include <linux/clk-provider.h>
   9 #include <linux/clk/renesas.h>
  10 #include <linux/init.h>
  11 #include <linux/io.h>
  12 #include <linux/kernel.h>
  13 #include <linux/slab.h>
  14 #include <linux/of.h>
  15 #include <linux/of_address.h>
  16 #include <linux/spinlock.h>
  17
  18 struct r8a7740_cpg {
  19         struct clk_onecell_data data;
  20         spinlock_t lock;
  21         void __iomem *reg;
  22 };
  23
  24 #define CPG_FRQCRA      0x00
  25 #define CPG_FRQCRB      0x04
  26 #define CPG_PLLC2CR     0x2c
  27 #define CPG_USBCKCR     0x8c
  28 #define CPG_FRQCRC      0xe0
  29
  30 #define CLK_ENABLE_ON_INIT BIT(0)
  31
  32 struct div4_clk {
  33         const char *name;
  34         unsigned int reg;
  35         unsigned int shift;
  36         int flags;
  37 };
  38
  39 static struct div4_clk div4_clks[] = {
  40         { "i", CPG_FRQCRA, 20, CLK_ENABLE_ON_INIT },
  41         { "zg", CPG_FRQCRA, 16, CLK_ENABLE_ON_INIT },
  42         { "b", CPG_FRQCRA,  8, CLK_ENABLE_ON_INIT },
  43         { "m1", CPG_FRQCRA,  4, CLK_ENABLE_ON_INIT },
  44         { "hp", CPG_FRQCRB,  4, 0 },
  45         { "hpp", CPG_FRQCRC, 20, 0 },
  46         { "usbp", CPG_FRQCRC, 16, 0 },
  47         { "s", CPG_FRQCRC, 12, 0 },
  48         { "zb", CPG_FRQCRC,  8, 0 },
  49         { "m3", CPG_FRQCRC,  4, 0 },
  50         { "cp", CPG_FRQCRC,  0, 0 },
  51         { NULL, 0, 0, 0 },
  52 };
  53
  54 static const struct clk_div_table div4_div_table[] = {
  55         { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
  56         { 6, 16 }, { 7, 18 }, { 8, 24 }, { 9, 32 }, { 10, 36 }, { 11, 48 },
  57         { 13, 72 }, { 14, 96 }, { 0, 0 }
  58 };
  59
  60 static u32 cpg_mode __initdata;
  61
  62 static struct clk * __init
  63 r8a7740_cpg_register_clock(struct device_node *np, struct r8a7740_cpg *cpg,
  64                              const char *name)
  65 {
  66         const struct clk_div_table *table = NULL;
  67         const char *parent_name;
  68         unsigned int shift, reg;
  69         unsigned int mult = 1;
  70         unsigned int div = 1;
  71
  72         if (!strcmp(name, "r")) {
  73                 switch (cpg_mode & (BIT(2) | BIT(1))) {
  74                 case BIT(1) | BIT(2):
  75                         /* extal1 */
  76                         parent_name = of_clk_get_parent_name(np, 0);
  77                         div = 2048;
  78                         break;
  79                 case BIT(2):
  80                         /* extal1 */
  81                         parent_name = of_clk_get_parent_name(np, 0);
  82                         div = 1024;
  83                         break;
  84                 default:
  85                         /* extalr */
  86                         parent_name = of_clk_get_parent_name(np, 2);
  87                         break;
  88                 }
  89         } else if (!strcmp(name, "system")) {
  90                 parent_name = of_clk_get_parent_name(np, 0);
  91                 if (cpg_mode & BIT(1))
  92                         div = 2;
  93         } else if (!strcmp(name, "pllc0")) {
  94                 /* PLLC0/1 are configurable multiplier clocks. Register them as
  95                  * fixed factor clocks for now as there's no generic multiplier
  96                  * clock implementation and we currently have no need to change
  97                  * the multiplier value.
  98                  */
  99                 u32 value = readl(cpg->reg + CPG_FRQCRC);
 100                 parent_name = "system";
 101                 mult = ((value >> 24) & 0x7f) + 1;
 102         } else if (!strcmp(name, "pllc1")) {
 103                 u32 value = readl(cpg->reg + CPG_FRQCRA);
 104                 parent_name = "system";
 105                 mult = ((value >> 24) & 0x7f) + 1;
 106                 div = 2;
 107         } else if (!strcmp(name, "pllc2")) {
 108                 u32 value = readl(cpg->reg + CPG_PLLC2CR);
 109                 parent_name = "system";
 110                 mult = ((value >> 24) & 0x3f) + 1;
 111         } else if (!strcmp(name, "usb24s")) {
 112                 u32 value = readl(cpg->reg + CPG_USBCKCR);
 113                 if (value & BIT(7))
 114                         /* extal2 */
 115                         parent_name = of_clk_get_parent_name(np, 1);
 116                 else
 117                         parent_name = "system";
 118                 if (!(value & BIT(6)))
 119                         div = 2;
 120         } else {
 121                 struct div4_clk *c;
 122                 for (c = div4_clks; c->name; c++) {
 123                         if (!strcmp(name, c->name)) {
 124                                 parent_name = "pllc1";
 125                                 table = div4_div_table;
 126                                 reg = c->reg;
 127                                 shift = c->shift;
 128                                 break;
 129                         }
 130                 }
 131                 if (!c->name)
 132                         return ERR_PTR(-EINVAL);
 133         }
 134
 135         if (!table) {
 136                 return clk_register_fixed_factor(NULL, name, parent_name, 0,
 137                                                  mult, div);
 138         } else {
 139                 return clk_register_divider_table(NULL, name, parent_name, 0,
 140                                                   cpg->reg + reg, shift, 4, 0,
 141                                                   table, &cpg->lock);
 142         }
 143 }
 144
 145 static void __init r8a7740_cpg_clocks_init(struct device_node *np)
 146 {
 147         struct r8a7740_cpg *cpg;
 148         struct clk **clks;
 149         unsigned int i;
 150         int num_clks;
 151
 152         if (of_property_read_u32(np, "renesas,mode", &cpg_mode))
 153                 pr_warn("%s: missing renesas,mode property\n", __func__);
 154
 155         num_clks = of_property_count_strings(np, "clock-output-names");
 156         if (num_clks < 0) {
 157                 pr_err("%s: failed to count clocks\n", __func__);
 158                 return;
 159         }
 160
 161         cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
 162         clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
 163         if (cpg == NULL || clks == NULL) {
 164                 /* We're leaking memory on purpose, there's no point in cleaning
 165                  * up as the system won't boot anyway.
 166                  */
 167                 return;
 168         }
 169
 170         spin_lock_init(&cpg->lock);
 171
 172         cpg->data.clks = clks;
 173         cpg->data.clk_num = num_clks;
 174
 175         cpg->reg = of_iomap(np, 0);
 176         if (WARN_ON(cpg->reg == NULL))
 177                 return;
 178
 179         for (i = 0; i < num_clks; ++i) {
 180                 const char *name;
 181                 struct clk *clk;
 182
 183                 of_property_read_string_index(np, "clock-output-names", i,
 184                                               &name);
 185
 186                 clk = r8a7740_cpg_register_clock(np, cpg, name);
 187                 if (IS_ERR(clk))
 188                         pr_err("%s: failed to register %pOFn %s clock (%ld)\n",
 189                                __func__, np, name, PTR_ERR(clk));
 190                 else
 191                         cpg->data.clks[i] = clk;
 192         }
 193
 194         of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
 195 }
 196 CLK_OF_DECLARE(r8a7740_cpg_clks, "renesas,r8a7740-cpg-clocks",
 197                r8a7740_cpg_clocks_init);