kernel/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 #include "clock.h"
  27
  28 #undef pr_fmt
  29 #define pr_fmt(fmt) "%s: " fmt, __func__
  30
  31 #define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
  32
  33 static unsigned long ti_composite_recalc_rate(struct clk_hw *hw,
  34                                               unsigned long parent_rate)
  35 {
  36         return ti_clk_divider_ops.recalc_rate(hw, parent_rate);
  37 }
  38
  39 static long ti_composite_round_rate(struct clk_hw *hw, unsigned long rate,
  40                                     unsigned long *prate)
  41 {
  42         return -EINVAL;
  43 }
  44
  45 static int ti_composite_set_rate(struct clk_hw *hw, unsigned long rate,
  46                                  unsigned long parent_rate)
  47 {
  48         return -EINVAL;
  49 }
  50
  51 static const struct clk_ops ti_composite_divider_ops = {
  52         .recalc_rate    = &ti_composite_recalc_rate,
  53         .round_rate     = &ti_composite_round_rate,
  54         .set_rate       = &ti_composite_set_rate,
  55 };
  56
  57 static const struct clk_ops ti_composite_gate_ops = {
  58         .enable         = &omap2_dflt_clk_enable,
  59         .disable        = &omap2_dflt_clk_disable,
  60         .is_enabled     = &omap2_dflt_clk_is_enabled,
  61 };
  62
  63 struct component_clk {
  64         int num_parents;
  65         const char **parent_names;
  66         struct device_node *node;
  67         int type;
  68         struct clk_hw *hw;
  69         struct list_head link;
  70 };
  71
  72 static const char * const component_clk_types[] __initconst = {
  73         "gate", "divider", "mux"
  74 };
  75
  76 static LIST_HEAD(component_clks);
  77
  78 static struct device_node *_get_component_node(struct device_node *node, int i)
  79 {
  80         int rc;
  81         struct of_phandle_args clkspec;
  82
  83         rc = of_parse_phandle_with_args(node, "clocks", "#clock-cells", i,
  84                                         &clkspec);
  85         if (rc)
  86                 return NULL;
  87
  88         return clkspec.np;
  89 }
  90
  91 static struct component_clk *_lookup_component(struct device_node *node)
  92 {
  93         struct component_clk *comp;
  94
  95         list_for_each_entry(comp, &component_clks, link) {
  96                 if (comp->node == node)
  97                         return comp;
  98         }
  99         return NULL;
 100 }
 101
 102 struct clk_hw_omap_comp {
 103         struct clk_hw hw;
 104         struct device_node *comp_nodes[CLK_COMPONENT_TYPE_MAX];
 105         struct component_clk *comp_clks[CLK_COMPONENT_TYPE_MAX];
 106 };
 107
 108 static inline struct clk_hw *_get_hw(struct clk_hw_omap_comp *clk, int idx)
 109 {
 110         if (!clk)
 111                 return NULL;
 112
 113         if (!clk->comp_clks[idx])
 114                 return NULL;
 115
 116         return clk->comp_clks[idx]->hw;
 117 }
 118
 119 #define to_clk_hw_comp(_hw) container_of(_hw, struct clk_hw_omap_comp, hw)
 120
 121 #if defined(CONFIG_ARCH_OMAP3) && defined(CONFIG_ATAGS)
 122 struct clk *ti_clk_register_composite(struct ti_clk *setup)
 123 {
 124         struct ti_clk_composite *comp;
 125         struct clk_hw *gate;
 126         struct clk_hw *mux;
 127         struct clk_hw *div;
 128         int num_parents = 1;
 129         const char **parent_names = NULL;
 130         struct clk *clk;
 131
 132         comp = setup->data;
 133
 134         div = ti_clk_build_component_div(comp->divider);
 135         gate = ti_clk_build_component_gate(comp->gate);
 136         mux = ti_clk_build_component_mux(comp->mux);
 137
 138         if (div)
 139                 parent_names = &comp->divider->parent;
 140
 141         if (gate)
 142                 parent_names = &comp->gate->parent;
 143
 144         if (mux) {
 145                 num_parents = comp->mux->num_parents;
 146                 parent_names = comp->mux->parents;
 147         }
 148
 149         clk = clk_register_composite(NULL, setup->name,
 150                                      parent_names, num_parents, mux,
 151                                      &ti_clk_mux_ops, div,
 152                                      &ti_composite_divider_ops, gate,
 153                                      &ti_composite_gate_ops, 0);
 154
 155         return clk;
 156 }
 157 #endif
 158
 159 static void __init _register_composite(struct clk_hw *hw,
 160                                        struct device_node *node)
 161 {
 162         struct clk *clk;
 163         struct clk_hw_omap_comp *cclk = to_clk_hw_comp(hw);
 164         struct component_clk *comp;
 165         int num_parents = 0;
 166         const char **parent_names = NULL;
 167         int i;
 168
 169         /* Check for presence of each component clock */
 170         for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
 171                 if (!cclk->comp_nodes[i])
 172                         continue;
 173
 174                 comp = _lookup_component(cclk->comp_nodes[i]);
 175                 if (!comp) {
 176                         pr_debug("component %s not ready for %s, retry\n",
 177                                  cclk->comp_nodes[i]->name, node->name);
 178                         if (!ti_clk_retry_init(node, hw,
 179                                                _register_composite))
 180                                 return;
 181
 182                         goto cleanup;
 183                 }
 184                 if (cclk->comp_clks[comp->type] != NULL) {
 185                         pr_err("duplicate component types for %s (%s)!\n",
 186                                node->name, component_clk_types[comp->type]);
 187                         goto cleanup;
 188                 }
 189
 190                 cclk->comp_clks[comp->type] = comp;
 191
 192                 /* Mark this node as found */
 193                 cclk->comp_nodes[i] = NULL;
 194         }
 195
 196         /* All components exists, proceed with registration */
 197         for (i = CLK_COMPONENT_TYPE_MAX - 1; i >= 0; i--) {
 198                 comp = cclk->comp_clks[i];
 199                 if (!comp)
 200                         continue;
 201                 if (comp->num_parents) {
 202                         num_parents = comp->num_parents;
 203                         parent_names = comp->parent_names;
 204                         break;
 205                 }
 206         }
 207
 208         if (!num_parents) {
 209                 pr_err("%s: no parents found for %s!\n", __func__, node->name);
 210                 goto cleanup;
 211         }
 212
 213         clk = clk_register_composite(NULL, node->name,
 214                                      parent_names, num_parents,
 215                                      _get_hw(cclk, CLK_COMPONENT_TYPE_MUX),
 216                                      &ti_clk_mux_ops,
 217                                      _get_hw(cclk, CLK_COMPONENT_TYPE_DIVIDER),
 218                                      &ti_composite_divider_ops,
 219                                      _get_hw(cclk, CLK_COMPONENT_TYPE_GATE),
 220                                      &ti_composite_gate_ops, 0);
 221
 222         if (!IS_ERR(clk))
 223                 of_clk_add_provider(node, of_clk_src_simple_get, clk);
 224
 225 cleanup:
 226         /* Free component clock list entries */
 227         for (i = 0; i < CLK_COMPONENT_TYPE_MAX; i++) {
 228                 if (!cclk->comp_clks[i])
 229                         continue;
 230                 list_del(&cclk->comp_clks[i]->link);
 231                 kfree(cclk->comp_clks[i]);
 232         }
 233
 234         kfree(cclk);
 235 }
 236
 237 static void __init of_ti_composite_clk_setup(struct device_node *node)
 238 {
 239         int num_clks;
 240         int i;
 241         struct clk_hw_omap_comp *cclk;
 242
 243         /* Number of component clocks to be put inside this clock */
 244         num_clks = of_clk_get_parent_count(node);
 245
 246         if (num_clks < 1) {
 247                 pr_err("composite clk %s must have component(s)\n", node->name);
 248                 return;
 249         }
 250
 251         cclk = kzalloc(sizeof(*cclk), GFP_KERNEL);
 252         if (!cclk)
 253                 return;
 254
 255         /* Get device node pointers for each component clock */
 256         for (i = 0; i < num_clks; i++)
 257                 cclk->comp_nodes[i] = _get_component_node(node, i);
 258
 259         _register_composite(&cclk->hw, node);
 260 }
 261 CLK_OF_DECLARE(ti_composite_clock, "ti,composite-clock",
 262                of_ti_composite_clk_setup);
 263
 264 /**
 265  * ti_clk_add_component - add a component clock to the pool
 266  * @node: device node of the component clock
 267  * @hw: hardware clock definition for the component clock
 268  * @type: type of the component clock
 269  *
 270  * Adds a component clock to the list of available components, so that
 271  * it can be registered by a composite clock.
 272  */
 273 int __init ti_clk_add_component(struct device_node *node, struct clk_hw *hw,
 274                                 int type)
 275 {
 276         int num_parents;
 277         const char **parent_names;
 278         struct component_clk *clk;
 279         int i;
 280
 281         num_parents = of_clk_get_parent_count(node);
 282
 283         if (num_parents < 1) {
 284                 pr_err("component-clock %s must have parent(s)\n", node->name);
 285                 return -EINVAL;
 286         }
 287
 288         parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL);
 289         if (!parent_names)
 290                 return -ENOMEM;
 291
 292         for (i = 0; i < num_parents; i++)
 293                 parent_names[i] = of_clk_get_parent_name(node, i);
 294
 295         clk = kzalloc(sizeof(*clk), GFP_KERNEL);
 296         if (!clk) {
 297                 kfree(parent_names);
 298                 return -ENOMEM;
 299         }
 300
 301         clk->num_parents = num_parents;
 302         clk->parent_names = parent_names;
 303         clk->hw = hw;
 304         clk->node = node;
 305         clk->type = type;
 306         list_add(&clk->link, &component_clks);
 307
 308         return 0;
 309 }