drivers/clk/shmobile/clk-r8a7779.c

   1 /*
   2  * r8a7779 Core CPG Clocks
   3  *
   4  * Copyright (C) 2013, 2014 Horms Solutions Ltd.
   5  *
   6  * Contact: Simon Horman <horms@verge.net.au>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; version 2 of the License.
  11  */
  12
  13 #include <linux/clk-provider.h>
  14 #include <linux/clkdev.h>
  15 #include <linux/clk/shmobile.h>
  16 #include <linux/init.h>
  17 #include <linux/kernel.h>
  18 #include <linux/of.h>
  19 #include <linux/of_address.h>
  20 #include <linux/spinlock.h>
  21
  22 #include <dt-bindings/clock/r8a7779-clock.h>
  23
  24 #define CPG_NUM_CLOCKS                  (R8A7779_CLK_OUT + 1)
  25
  26 struct r8a7779_cpg {
  27         struct clk_onecell_data data;
  28         spinlock_t lock;
  29         void __iomem *reg;
  30 };
  31
  32 /* -----------------------------------------------------------------------------
  33  * CPG Clock Data
  34  */
  35
  36 /*
  37  *              MD1 = 1                 MD1 = 0
  38  *              (PLLA = 1500)           (PLLA = 1600)
  39  *              (MHz)                   (MHz)
  40  *------------------------------------------------+--------------------
  41  * clkz         1000   (2/3)            800   (1/2)
  42  * clkzs         250   (1/6)            200   (1/8)
  43  * clki          750   (1/2)            800   (1/2)
  44  * clks          250   (1/6)            200   (1/8)
  45  * clks1         125   (1/12)           100   (1/16)
  46  * clks3         187.5 (1/8)            200   (1/8)
  47  * clks4          93.7 (1/16)           100   (1/16)
  48  * clkp           62.5 (1/24)            50   (1/32)
  49  * clkg           62.5 (1/24)            66.6 (1/24)
  50  * clkb, CLKOUT
  51  * (MD2 = 0)      62.5 (1/24)            66.6 (1/24)
  52  * (MD2 = 1)      41.6 (1/36)            50   (1/32)
  53  */
  54
  55 #define CPG_CLK_CONFIG_INDEX(md)        (((md) & (BIT(2)|BIT(1))) >> 1)
  56
  57 struct cpg_clk_config {
  58         unsigned int z_mult;
  59         unsigned int z_div;
  60         unsigned int zs_and_s_div;
  61         unsigned int s1_div;
  62         unsigned int p_div;
  63         unsigned int b_and_out_div;
  64 };
  65
  66 static const struct cpg_clk_config cpg_clk_configs[4] __initconst = {
  67         { 1, 2, 8, 16, 32, 24 },
  68         { 2, 3, 6, 12, 24, 24 },
  69         { 1, 2, 8, 16, 32, 32 },
  70         { 2, 3, 6, 12, 24, 36 },
  71 };
  72
  73 /*
  74  *   MD         PLLA Ratio
  75  * 12 11
  76  *------------------------
  77  * 0  0         x42
  78  * 0  1         x48
  79  * 1  0         x56
  80  * 1  1         x64
  81  */
  82
  83 #define CPG_PLLA_MULT_INDEX(md) (((md) & (BIT(12)|BIT(11))) >> 11)
  84
  85 static const unsigned int cpg_plla_mult[4] __initconst = { 42, 48, 56, 64 };
  86
  87 /* -----------------------------------------------------------------------------
  88  * Initialization
  89  */
  90
  91 static u32 cpg_mode __initdata;
  92
  93 static struct clk * __init
  94 r8a7779_cpg_register_clock(struct device_node *np, struct r8a7779_cpg *cpg,
  95                            const struct cpg_clk_config *config,
  96                            unsigned int plla_mult, const char *name)
  97 {
  98         const char *parent_name = "plla";
  99         unsigned int mult = 1;
 100         unsigned int div = 1;
 101
 102         if (!strcmp(name, "plla")) {
 103                 parent_name = of_clk_get_parent_name(np, 0);
 104                 mult = plla_mult;
 105         } else if (!strcmp(name, "z")) {
 106                 div = config->z_div;
 107                 mult = config->z_mult;
 108         } else if (!strcmp(name, "zs") || !strcmp(name, "s")) {
 109                 div = config->zs_and_s_div;
 110         } else if (!strcmp(name, "s1")) {
 111                 div = config->s1_div;
 112         } else if (!strcmp(name, "p")) {
 113                 div = config->p_div;
 114         } else if (!strcmp(name, "b") || !strcmp(name, "out")) {
 115                 div = config->b_and_out_div;
 116         } else {
 117                 return ERR_PTR(-EINVAL);
 118         }
 119
 120         return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, div);
 121 }
 122
 123 static void __init r8a7779_cpg_clocks_init(struct device_node *np)
 124 {
 125         const struct cpg_clk_config *config;
 126         struct r8a7779_cpg *cpg;
 127         struct clk **clks;
 128         unsigned int i, plla_mult;
 129         int num_clks;
 130
 131         num_clks = of_property_count_strings(np, "clock-output-names");
 132         if (num_clks < 0) {
 133                 pr_err("%s: failed to count clocks\n", __func__);
 134                 return;
 135         }
 136
 137         cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
 138         clks = kzalloc(CPG_NUM_CLOCKS * sizeof(*clks), GFP_KERNEL);
 139         if (cpg == NULL || clks == NULL) {
 140                 /* We're leaking memory on purpose, there's no point in cleaning
 141                  * up as the system won't boot anyway.
 142                  */
 143                 return;
 144         }
 145
 146         spin_lock_init(&cpg->lock);
 147
 148         cpg->data.clks = clks;
 149         cpg->data.clk_num = num_clks;
 150
 151         config = &cpg_clk_configs[CPG_CLK_CONFIG_INDEX(cpg_mode)];
 152         plla_mult = cpg_plla_mult[CPG_PLLA_MULT_INDEX(cpg_mode)];
 153
 154         for (i = 0; i < num_clks; ++i) {
 155                 const char *name;
 156                 struct clk *clk;
 157
 158                 of_property_read_string_index(np, "clock-output-names", i,
 159                                               &name);
 160
 161                 clk = r8a7779_cpg_register_clock(np, cpg, config,
 162                                                  plla_mult, name);
 163                 if (IS_ERR(clk))
 164                         pr_err("%s: failed to register %s %s clock (%ld)\n",
 165                                __func__, np->name, name, PTR_ERR(clk));
 166                 else
 167                         cpg->data.clks[i] = clk;
 168         }
 169
 170         of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
 171 }
 172 CLK_OF_DECLARE(r8a7779_cpg_clks, "renesas,r8a7779-cpg-clocks",
 173                r8a7779_cpg_clocks_init);
 174
 175 void __init r8a7779_clocks_init(u32 mode)
 176 {
 177         cpg_mode = mode;
 178
 179         of_clk_init(NULL);
 180 }