linux/drivers/clk/renesas/clk-r8a7740.c
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   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
  18struct 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
  32struct div4_clk {
  33        const char *name;
  34        unsigned int reg;
  35        unsigned int shift;
  36        int flags;
  37};
  38
  39static 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
  54static 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
  60static u32 cpg_mode __initdata;
  61
  62static struct clk * __init
  63r8a7740_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
 145static 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}
 196CLK_OF_DECLARE(r8a7740_cpg_clks, "renesas,r8a7740-cpg-clocks",
 197               r8a7740_cpg_clocks_init);
 198