drivers/clk/ti/composite.c

   1 /*
   2  * TI composite clock support
   3  *
   4  * Copyright (C) 2013 Texas Instruments, Inc.
   5  *
   6  * Tero Kristo <t-kristo@ti.com>
   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 version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  13  * kind, whether express or implied; without even the implied warranty
  14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/clk-provider.h>
  19 #include <linux/slab.h>
  20 #include <linux/io.h>
  21 #include <linux/of.h>
  22 #include <linux/of_address.h>
  23 #include <linux/clk/ti.h>
  24 #include <linux/list.h>
  25
  26 #undef pr_fmt
  27 #define pr_fmt(fmt) "%s: " fmt, __func__
  28
  29 #define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
  30
  31 static unsigned long ti_composite_recalc_rate(struct clk_hw *hw,
  32                                               unsigned long parent_rate)
  33 {
  34         return ti_clk_divider_ops.recalc_rate(hw, parent_rate);
  35 }
  36
  37 static long ti_composite_round_rate(struct clk_hw *hw, unsigned long rate,
  38                                     unsigned long *prate)
  39 {
  40         return -EINVAL;
  41 }
  42
  43 static int ti_composite_set_rate(struct clk_hw *hw, unsigned long rate,
  44                                  unsigned long parent_rate)
  45 {
  46         return -EINVAL;
  47 }
  48
  49 static const struct clk_ops ti_composite_divider_ops = {
  50         .recalc_rate    = &ti_composite_recalc_rate,
  51         .round_rate     = &ti_composite_round_rate,
  52         .set_rate       = &ti_composite_set_rate,
  53 };
  54
  55 static const struct clk_ops ti_composite_gate_ops = {
  56         .enable         = &omap2_dflt_clk_enable,
  57         .disable        = &omap2_dflt_clk_disable,
  58         .is_enabled     = &omap2_dflt_clk_is_enabled,
  59 };
  60
  61 struct component_clk {
  62         int num_parents;
  63         const char **parent_names;
  64         struct device_node *node;
  65         int type;
  66         struct clk_hw *hw;
  67         struct list_head link;
  68 };
  69
  70 static const char * __initconst component_clk_types[] = {
  71         "gate", "divider", "mux"
  72 };
  73
  74 static LIST_HEAD(component_clks);
  75
  76 static struct device_node *_get_component_node(struct device_node *node, int i)
  77 {
  78         int rc;
  79         struct of_phandle_args clkspec;
  80
  81         rc = of_parse_phandle_with_args(node, "clocks", "#clock-cells", i,
  82                                         &clkspec);
  83         if (rc)
  84                 return NULL;
  85
  86         return clkspec.np;
  87 }
  88
  89 static struct component_clk *_lookup_component(struct device_node *node)
  90 {
  91         struct component_clk *comp;
  92
  93         list_for_each_entry(comp, &component_clks, link) {
  94                 if (comp->node == node)
  95                         return comp;
  96         }
  97         return NULL;
  98 }
  99
 100 struct clk_hw_omap_comp {
 101         struct clk_hw hw;
 102         struct device_node *comp_nodes[CLK_COMPONENT_TYPE_MAX];
 103         struct component_clk *comp_clks[CLK_COMPONENT_TYPE_MAX];
 104 };
 105
 106 static inline struct clk_hw *_get_hw(struct clk_hw_omap_comp *clk, int idx)
 107 {
 108         if (!clk)
 109                 return NULL;
 110
 111         if (!clk->comp_clks[idx])
 112                 return NULL;
 113
 114         return clk->comp_clks[idx]->hw;
 115 }
 116
 117 #define to_clk_hw_comp(_hw) container_of(_hw, struct clk_hw_omap_comp, hw)
 118
 119 static void __init ti_clk_register_composite(struct clk_hw *hw,
 120                                              struct device_node *node)
 121 {
 122         struct clk *clk;
 123         struct clk_hw_omap_comp *cclk = to_clk_hw_comp(hw);
 124         struct component_clk *comp;
 125         int num_parents = 0;
 126         const char **parent_names = NULL;
 127         int i;
 128
 129         /* Check for presence of each component clock */
 130         for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
 131                 if (!cclk->comp_nodes[i])
 132                         continue;
 133
 134                 comp = _lookup_component(cclk->comp_nodes[i]);
 135                 if (!comp) {
 136                         pr_debug("component %s not ready for %s, retry\n",
 137                                  cclk->comp_nodes[i]->name, node->name);
 138                         if (!ti_clk_retry_init(node, hw,
 139                                                ti_clk_register_composite))
 140                                 return;
 141
 142                         goto cleanup;
 143                 }
 144                 if (cclk->comp_clks[comp->type] != NULL) {
 145                         pr_err("duplicate component types for %s (%s)!\n",
 146                                node->name, component_clk_types[comp->type]);
 147                         goto cleanup;
 148                 }
 149
 150                 cclk->comp_clks[comp->type] = comp;
 151
 152                 /* Mark this node as found */
 153                 cclk->comp_nodes[i] = NULL;
 154         }
 155
 156         /* All components exists, proceed with registration */
 157         for (i = CLK_COMPONENT_TYPE_MAX - 1; i >= 0; i--) {
 158                 comp = cclk->comp_clks[i];
 159                 if (!comp)
 160                         continue;
 161                 if (comp->num_parents) {
 162                         num_parents = comp->num_parents;
 163                         parent_names = comp->parent_names;
 164                         break;
 165                 }
 166         }
 167
 168         if (!num_parents) {
 169                 pr_err("%s: no parents found for %s!\n", __func__, node->name);
 170                 goto cleanup;
 171         }
 172
 173         clk = clk_register_composite(NULL, node->name,
 174                                      parent_names, num_parents,
 175                                      _get_hw(cclk, CLK_COMPONENT_TYPE_MUX),
 176                                      &ti_clk_mux_ops,
 177                                      _get_hw(cclk, CLK_COMPONENT_TYPE_DIVIDER),
 178                                      &ti_composite_divider_ops,
 179                                      _get_hw(cclk, CLK_COMPONENT_TYPE_GATE),
 180                                      &ti_composite_gate_ops, 0);
 181
 182         if (!IS_ERR(clk))
 183                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 184
 185 cleanup:
 186         /* Free component clock list entries */
 187         for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
 188                 if (!cclk->comp_clks[i])
 189                         continue;
 190                 list_del(&cclk->comp_clks[i]->link);
 191                 kfree(cclk->comp_clks[i]);
 192         }
 193
 194         kfree(cclk);
 195 }
 196
 197 static void __init of_ti_composite_clk_setup(struct device_node *node)
 198 {
 199         int num_clks;
 200         int i;
 201         struct clk_hw_omap_comp *cclk;
 202
 203         /* Number of component clocks to be put inside this clock */
 204         num_clks = of_clk_get_parent_count(node);
 205
 206         if (num_clks < 1) {
 207                 pr_err("composite clk %s must have component(s)\n", node->name);
 208                 return;
 209         }
 210
 211         cclk = kzalloc(sizeof(*cclk), GFP_KERNEL);
 212         if (!cclk)
 213                 return;
 214
 215         /* Get device node pointers for each component clock */
 216         for (i = 0; i < num_clks; i++)
 217                 cclk->comp_nodes[i] = _get_component_node(node, i);
 218
 219         ti_clk_register_composite(&cclk->hw, node);
 220 }
 221 CLK_OF_DECLARE(ti_composite_clock, "ti,composite-clock",
 222                of_ti_composite_clk_setup);
 223
 224 /**
 225  * ti_clk_add_component - add a component clock to the pool
 226  * @node: device node of the component clock
 227  * @hw: hardware clock definition for the component clock
 228  * @type: type of the component clock
 229  *
 230  * Adds a component clock to the list of available components, so that
 231  * it can be registered by a composite clock.
 232  */
 233 int __init ti_clk_add_component(struct device_node *node, struct clk_hw *hw,
 234                                 int type)
 235 {
 236         int num_parents;
 237         const char **parent_names;
 238         struct component_clk *clk;
 239         int i;
 240
 241         num_parents = of_clk_get_parent_count(node);
 242
 243         if (num_parents < 1) {
 244                 pr_err("component-clock %s must have parent(s)\n", node->name);
 245                 return -EINVAL;
 246         }
 247
 248         parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
 249         if (!parent_names)
 250                 return -ENOMEM;
 251
 252         for (i = 0; i < num_parents; i++)
 253                 parent_names[i] = of_clk_get_parent_name(node, i);
 254
 255         clk = kzalloc(sizeof(*clk), GFP_KERNEL);
 256         if (!clk) {
 257                 kfree(parent_names);
 258                 return -ENOMEM;
 259         }
 260
 261         clk->num_parents = num_parents;
 262         clk->parent_names = parent_names;
 263         clk->hw = hw;
 264         clk->node = node;
 265         clk->type = type;
 266         list_add(&clk->link, &component_clks);
 267
 268         return 0;
 269 }