drivers/clk/renesas/clk-r8a7778.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * r8a7778 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/of_address.h>
  11 #include <linux/slab.h>
  12 #include <linux/soc/renesas/rcar-rst.h>
  13
  14 struct r8a7778_cpg {
  15         struct clk_onecell_data data;
  16         spinlock_t lock;
  17         void __iomem *reg;
  18 };
  19
  20 /* PLL multipliers per bits 11, 12, and 18 of MODEMR */
  21 static const struct {
  22         unsigned long plla_mult;
  23         unsigned long pllb_mult;
  24 } r8a7778_rates[] __initconst = {
  25         [0] = { 21, 21 },
  26         [1] = { 24, 24 },
  27         [2] = { 28, 28 },
  28         [3] = { 32, 32 },
  29         [5] = { 24, 21 },
  30         [6] = { 28, 21 },
  31         [7] = { 32, 24 },
  32 };
  33
  34 /* Clock dividers per bits 1 and 2 of MODEMR */
  35 static const struct {
  36         const char *name;
  37         unsigned int div[4];
  38 } r8a7778_divs[6] __initconst = {
  39         { "b",   { 12, 12, 16, 18 } },
  40         { "out", { 12, 12, 16, 18 } },
  41         { "p",   { 16, 12, 16, 12 } },
  42         { "s",   { 4,  3,  4,  3  } },
  43         { "s1",  { 8,  6,  8,  6  } },
  44 };
  45
  46 static u32 cpg_mode_rates __initdata;
  47 static u32 cpg_mode_divs __initdata;
  48
  49 static struct clk * __init
  50 r8a7778_cpg_register_clock(struct device_node *np, struct r8a7778_cpg *cpg,
  51                              const char *name)
  52 {
  53         if (!strcmp(name, "plla")) {
  54                 return clk_register_fixed_factor(NULL, "plla",
  55                         of_clk_get_parent_name(np, 0), 0,
  56                         r8a7778_rates[cpg_mode_rates].plla_mult, 1);
  57         } else if (!strcmp(name, "pllb")) {
  58                 return clk_register_fixed_factor(NULL, "pllb",
  59                         of_clk_get_parent_name(np, 0), 0,
  60                         r8a7778_rates[cpg_mode_rates].pllb_mult, 1);
  61         } else {
  62                 unsigned int i;
  63
  64                 for (i = 0; i < ARRAY_SIZE(r8a7778_divs); i++) {
  65                         if (!strcmp(name, r8a7778_divs[i].name)) {
  66                                 return clk_register_fixed_factor(NULL,
  67                                         r8a7778_divs[i].name,
  68                                         "plla", 0, 1,
  69                                         r8a7778_divs[i].div[cpg_mode_divs]);
  70                         }
  71                 }
  72         }
  73
  74         return ERR_PTR(-EINVAL);
  75 }
  76
  77
  78 static void __init r8a7778_cpg_clocks_init(struct device_node *np)
  79 {
  80         struct r8a7778_cpg *cpg;
  81         struct clk **clks;
  82         unsigned int i;
  83         int num_clks;
  84         u32 mode;
  85
  86         if (rcar_rst_read_mode_pins(&mode))
  87                 return;
  88
  89         BUG_ON(!(mode & BIT(19)));
  90
  91         cpg_mode_rates = (!!(mode & BIT(18)) << 2) |
  92                          (!!(mode & BIT(12)) << 1) |
  93                          (!!(mode & BIT(11)));
  94         cpg_mode_divs = (!!(mode & BIT(2)) << 1) |
  95                         (!!(mode & BIT(1)));
  96
  97         num_clks = of_property_count_strings(np, "clock-output-names");
  98         if (num_clks < 0) {
  99                 pr_err("%s: failed to count clocks\n", __func__);
 100                 return;
 101         }
 102
 103         cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
 104         clks = kcalloc(num_clks, sizeof(*clks), GFP_KERNEL);
 105         if (cpg == NULL || clks == NULL) {
 106                 /* We're leaking memory on purpose, there's no point in cleaning
 107                  * up as the system won't boot anyway.
 108                  */
 109                 return;
 110         }
 111
 112         spin_lock_init(&cpg->lock);
 113
 114         cpg->data.clks = clks;
 115         cpg->data.clk_num = num_clks;
 116
 117         cpg->reg = of_iomap(np, 0);
 118         if (WARN_ON(cpg->reg == NULL))
 119                 return;
 120
 121         for (i = 0; i < num_clks; ++i) {
 122                 const char *name;
 123                 struct clk *clk;
 124
 125                 of_property_read_string_index(np, "clock-output-names", i,
 126                                               &name);
 127
 128                 clk = r8a7778_cpg_register_clock(np, cpg, name);
 129                 if (IS_ERR(clk))
 130                         pr_err("%s: failed to register %pOFn %s clock (%ld)\n",
 131                                __func__, np, name, PTR_ERR(clk));
 132                 else
 133                         cpg->data.clks[i] = clk;
 134         }
 135
 136         of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
 137
 138         cpg_mstp_add_clk_domain(np);
 139 }
 140
 141 CLK_OF_DECLARE(r8a7778_cpg_clks, "renesas,r8a7778-cpg-clocks",
 142                r8a7778_cpg_clocks_init);