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; 279 280 num_parents = of_clk_get_parent_count(node); 281 282 if (num_parents < 1) { 283 pr_err("component-clock %s must have parent(s)\n", node->name); 284 return -EINVAL; 285 } 286 287 parent_names = kzalloc((sizeof(char *) * num_parents), GFP_KERNEL); 288 if (!parent_names) 289 return -ENOMEM; 290 291 of_clk_parent_fill(node, parent_names, num_parents); 292 293 clk = kzalloc(sizeof(*clk), GFP_KERNEL); 294 if (!clk) { 295 kfree(parent_names); 296 return -ENOMEM; 297 } 298 299 clk->num_parents = num_parents; 300 clk->parent_names = parent_names; 301 clk->hw = hw; 302 clk->node = node; 303 clk->type = type; 304 list_add(&clk->link, &component_clks); 305 306 return 0; 307 } 308