drivers/clk/clk-conf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2014 Samsung Electronics Co., Ltd.
   4  * Sylwester Nawrocki <s.nawrocki@samsung.com>
   5  */
   6
   7 #include <linux/clk.h>
   8 #include <linux/clk-provider.h>
   9 #include <linux/clk/clk-conf.h>
  10 #include <linux/device.h>
  11 #include <linux/of.h>
  12 #include <linux/printk.h>
  13 #include <linux/slab.h>
  14
  15 static int __set_clk_parents(struct device_node *node, bool clk_supplier)
  16 {
  17         struct of_phandle_args clkspec;
  18         int index, rc, num_parents;
  19         struct clk *clk, *pclk;
  20
  21         num_parents = of_count_phandle_with_args(node, "assigned-clock-parents",
  22                                                  "#clock-cells");
  23         if (num_parents == -EINVAL)
  24                 pr_err("clk: invalid value of clock-parents property at %pOF\n",
  25                        node);
  26
  27         for (index = 0; index < num_parents; index++) {
  28                 rc = of_parse_phandle_with_args(node, "assigned-clock-parents",
  29                                         "#clock-cells", index, &clkspec);
  30                 if (rc < 0) {
  31                         /* skip empty (null) phandles */
  32                         if (rc == -ENOENT)
  33                                 continue;
  34                         else
  35                                 return rc;
  36                 }
  37                 if (clkspec.np == node && !clk_supplier) {
  38                         of_node_put(clkspec.np);
  39                         return 0;
  40                 }
  41                 pclk = of_clk_get_from_provider(&clkspec);
  42                 of_node_put(clkspec.np);
  43                 if (IS_ERR(pclk)) {
  44                         if (PTR_ERR(pclk) != -EPROBE_DEFER)
  45                                 pr_warn("clk: couldn't get parent clock %d for %pOF\n",
  46                                         index, node);
  47                         return PTR_ERR(pclk);
  48                 }
  49
  50                 rc = of_parse_phandle_with_args(node, "assigned-clocks",
  51                                         "#clock-cells", index, &clkspec);
  52                 if (rc < 0)
  53                         goto err;
  54                 if (clkspec.np == node && !clk_supplier) {
  55                         of_node_put(clkspec.np);
  56                         rc = 0;
  57                         goto err;
  58                 }
  59                 clk = of_clk_get_from_provider(&clkspec);
  60                 of_node_put(clkspec.np);
  61                 if (IS_ERR(clk)) {
  62                         if (PTR_ERR(clk) != -EPROBE_DEFER)
  63                                 pr_warn("clk: couldn't get assigned clock %d for %pOF\n",
  64                                         index, node);
  65                         rc = PTR_ERR(clk);
  66                         goto err;
  67                 }
  68
  69                 rc = clk_set_parent(clk, pclk);
  70                 if (rc < 0)
  71                         pr_err("clk: failed to reparent %s to %s: %d\n",
  72                                __clk_get_name(clk), __clk_get_name(pclk), rc);
  73                 clk_put(clk);
  74                 clk_put(pclk);
  75         }
  76         return 0;
  77 err:
  78         clk_put(pclk);
  79         return rc;
  80 }
  81
  82 static int __set_clk_rates(struct device_node *node, bool clk_supplier)
  83 {
  84         struct of_phandle_args clkspec;
  85         int rc, count, count_64, index;
  86         struct clk *clk;
  87         u64 *rates_64 __free(kfree) = NULL;
  88         u32 *rates __free(kfree) = NULL;
  89
  90         count = of_property_count_u32_elems(node, "assigned-clock-rates");
  91         count_64 = of_property_count_u64_elems(node, "assigned-clock-rates-u64");
  92         if (count_64 > 0) {
  93                 count = count_64;
  94                 rates_64 = kcalloc(count, sizeof(*rates_64), GFP_KERNEL);
  95                 if (!rates_64)
  96                         return -ENOMEM;
  97
  98                 rc = of_property_read_u64_array(node,
  99                                                 "assigned-clock-rates-u64",
 100                                                 rates_64, count);
 101         } else if (count > 0) {
 102                 rates = kcalloc(count, sizeof(*rates), GFP_KERNEL);
 103                 if (!rates)
 104                         return -ENOMEM;
 105
 106                 rc = of_property_read_u32_array(node, "assigned-clock-rates",
 107                                                 rates, count);
 108         } else {
 109                 return 0;
 110         }
 111
 112         if (rc)
 113                 return rc;
 114
 115         for (index = 0; index < count; index++) {
 116                 unsigned long rate;
 117
 118                 if (rates_64)
 119                         rate = rates_64[index];
 120                 else
 121                         rate = rates[index];
 122
 123                 if (rate) {
 124                         rc = of_parse_phandle_with_args(node, "assigned-clocks",
 125                                         "#clock-cells", index, &clkspec);
 126                         if (rc < 0) {
 127                                 /* skip empty (null) phandles */
 128                                 if (rc == -ENOENT)
 129                                         continue;
 130                                 else
 131                                         return rc;
 132                         }
 133                         if (clkspec.np == node && !clk_supplier) {
 134                                 of_node_put(clkspec.np);
 135                                 return 0;
 136                         }
 137
 138                         clk = of_clk_get_from_provider(&clkspec);
 139                         of_node_put(clkspec.np);
 140                         if (IS_ERR(clk)) {
 141                                 if (PTR_ERR(clk) != -EPROBE_DEFER)
 142                                         pr_warn("clk: couldn't get clock %d for %pOF\n",
 143                                                 index, node);
 144                                 return PTR_ERR(clk);
 145                         }
 146
 147                         rc = clk_set_rate(clk, rate);
 148                         if (rc < 0)
 149                                 pr_err("clk: couldn't set %s clk rate to %lu (%d), current rate: %lu\n",
 150                                        __clk_get_name(clk), rate, rc,
 151                                        clk_get_rate(clk));
 152                         clk_put(clk);
 153                 }
 154         }
 155         return 0;
 156 }
 157
 158 /**
 159  * of_clk_set_defaults() - parse and set assigned clocks configuration
 160  * @node: device node to apply clock settings for
 161  * @clk_supplier: true if clocks supplied by @node should also be considered
 162  *
 163  * This function parses 'assigned-{clocks/clock-parents/clock-rates}' properties
 164  * and sets any specified clock parents and rates. The @clk_supplier argument
 165  * should be set to true if @node may be also a clock supplier of any clock
 166  * listed in its 'assigned-clocks' or 'assigned-clock-parents' properties.
 167  * If @clk_supplier is false the function exits returning 0 as soon as it
 168  * determines the @node is also a supplier of any of the clocks.
 169  */
 170 int of_clk_set_defaults(struct device_node *node, bool clk_supplier)
 171 {
 172         int rc;
 173
 174         if (!node)
 175                 return 0;
 176
 177         rc = __set_clk_parents(node, clk_supplier);
 178         if (rc < 0)
 179                 return rc;
 180
 181         return __set_clk_rates(node, clk_supplier);
 182 }
 183 EXPORT_SYMBOL_GPL(of_clk_set_defaults);