1 /* 2 * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 */ 10 11 #include <linux/clk-provider.h> 12 #include <linux/clkdev.h> 13 #include <linux/clk/at91_pmc.h> 14 #include <linux/of.h> 15 #include <linux/mfd/syscon.h> 16 #include <linux/regmap.h> 17 18 #include "pmc.h" 19 20 #define PROG_SOURCE_MAX 5 21 #define PROG_ID_MAX 7 22 23 #define PROG_STATUS_MASK(id) (1 << ((id) + 8)) 24 #define PROG_PRES_MASK 0x7 25 #define PROG_PRES(layout, pckr) ((pckr >> layout->pres_shift) & PROG_PRES_MASK) 26 #define PROG_MAX_RM9200_CSS 3 27 28 struct clk_programmable_layout { 29 u8 pres_shift; 30 u8 css_mask; 31 u8 have_slck_mck; 32 }; 33 34 struct clk_programmable { 35 struct clk_hw hw; 36 struct regmap *regmap; 37 u8 id; 38 const struct clk_programmable_layout *layout; 39 }; 40 41 #define to_clk_programmable(hw) container_of(hw, struct clk_programmable, hw) 42 43 static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw, 44 unsigned long parent_rate) 45 { 46 struct clk_programmable *prog = to_clk_programmable(hw); 47 unsigned int pckr; 48 49 regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr); 50 51 return parent_rate >> PROG_PRES(prog->layout, pckr); 52 } 53 54 static int clk_programmable_determine_rate(struct clk_hw *hw, 55 struct clk_rate_request *req) 56 { 57 struct clk_hw *parent; 58 long best_rate = -EINVAL; 59 unsigned long parent_rate; 60 unsigned long tmp_rate; 61 int shift; 62 int i; 63 64 for (i = 0; i < clk_hw_get_num_parents(hw); i++) { 65 parent = clk_hw_get_parent_by_index(hw, i); 66 if (!parent) 67 continue; 68 69 parent_rate = clk_hw_get_rate(parent); 70 for (shift = 0; shift < PROG_PRES_MASK; shift++) { 71 tmp_rate = parent_rate >> shift; 72 if (tmp_rate <= req->rate) 73 break; 74 } 75 76 if (tmp_rate > req->rate) 77 continue; 78 79 if (best_rate < 0 || 80 (req->rate - tmp_rate) < (req->rate - best_rate)) { 81 best_rate = tmp_rate; 82 req->best_parent_rate = parent_rate; 83 req->best_parent_hw = parent; 84 } 85 86 if (!best_rate) 87 break; 88 } 89 90 if (best_rate < 0) 91 return best_rate; 92 93 req->rate = best_rate; 94 return 0; 95 } 96 97 static int clk_programmable_set_parent(struct clk_hw *hw, u8 index) 98 { 99 struct clk_programmable *prog = to_clk_programmable(hw); 100 const struct clk_programmable_layout *layout = prog->layout; 101 unsigned int mask = layout->css_mask; 102 unsigned int pckr = index; 103 104 if (layout->have_slck_mck) 105 mask |= AT91_PMC_CSSMCK_MCK; 106 107 if (index > layout->css_mask) { 108 if (index > PROG_MAX_RM9200_CSS && !layout->have_slck_mck) 109 return -EINVAL; 110 111 pckr |= AT91_PMC_CSSMCK_MCK; 112 } 113 114 regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id), mask, pckr); 115 116 return 0; 117 } 118 119 static u8 clk_programmable_get_parent(struct clk_hw *hw) 120 { 121 struct clk_programmable *prog = to_clk_programmable(hw); 122 const struct clk_programmable_layout *layout = prog->layout; 123 unsigned int pckr; 124 u8 ret; 125 126 regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr); 127 128 ret = pckr & layout->css_mask; 129 130 if (layout->have_slck_mck && (pckr & AT91_PMC_CSSMCK_MCK) && !ret) 131 ret = PROG_MAX_RM9200_CSS + 1; 132 133 return ret; 134 } 135 136 static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate, 137 unsigned long parent_rate) 138 { 139 struct clk_programmable *prog = to_clk_programmable(hw); 140 const struct clk_programmable_layout *layout = prog->layout; 141 unsigned long div = parent_rate / rate; 142 unsigned int pckr; 143 int shift = 0; 144 145 regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr); 146 147 if (!div) 148 return -EINVAL; 149 150 shift = fls(div) - 1; 151 152 if (div != (1 << shift)) 153 return -EINVAL; 154 155 if (shift >= PROG_PRES_MASK) 156 return -EINVAL; 157 158 regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id), 159 PROG_PRES_MASK << layout->pres_shift, 160 shift << layout->pres_shift); 161 162 return 0; 163 } 164 165 static const struct clk_ops programmable_ops = { 166 .recalc_rate = clk_programmable_recalc_rate, 167 .determine_rate = clk_programmable_determine_rate, 168 .get_parent = clk_programmable_get_parent, 169 .set_parent = clk_programmable_set_parent, 170 .set_rate = clk_programmable_set_rate, 171 }; 172 173 static struct clk_hw * __init 174 at91_clk_register_programmable(struct regmap *regmap, 175 const char *name, const char **parent_names, 176 u8 num_parents, u8 id, 177 const struct clk_programmable_layout *layout) 178 { 179 struct clk_programmable *prog; 180 struct clk_hw *hw; 181 struct clk_init_data init; 182 int ret; 183 184 if (id > PROG_ID_MAX) 185 return ERR_PTR(-EINVAL); 186 187 prog = kzalloc(sizeof(*prog), GFP_KERNEL); 188 if (!prog) 189 return ERR_PTR(-ENOMEM); 190 191 init.name = name; 192 init.ops = &programmable_ops; 193 init.parent_names = parent_names; 194 init.num_parents = num_parents; 195 init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; 196 197 prog->id = id; 198 prog->layout = layout; 199 prog->hw.init = &init; 200 prog->regmap = regmap; 201 202 hw = &prog->hw; 203 ret = clk_hw_register(NULL, &prog->hw); 204 if (ret) { 205 kfree(prog); 206 hw = ERR_PTR(ret); 207 } 208 209 return hw; 210 } 211 212 static const struct clk_programmable_layout at91rm9200_programmable_layout = { 213 .pres_shift = 2, 214 .css_mask = 0x3, 215 .have_slck_mck = 0, 216 }; 217 218 static const struct clk_programmable_layout at91sam9g45_programmable_layout = { 219 .pres_shift = 2, 220 .css_mask = 0x3, 221 .have_slck_mck = 1, 222 }; 223 224 static const struct clk_programmable_layout at91sam9x5_programmable_layout = { 225 .pres_shift = 4, 226 .css_mask = 0x7, 227 .have_slck_mck = 0, 228 }; 229 230 static void __init 231 of_at91_clk_prog_setup(struct device_node *np, 232 const struct clk_programmable_layout *layout) 233 { 234 int num; 235 u32 id; 236 struct clk_hw *hw; 237 unsigned int num_parents; 238 const char *parent_names[PROG_SOURCE_MAX]; 239 const char *name; 240 struct device_node *progclknp; 241 struct regmap *regmap; 242 243 num_parents = of_clk_get_parent_count(np); 244 if (num_parents == 0 || num_parents > PROG_SOURCE_MAX) 245 return; 246 247 of_clk_parent_fill(np, parent_names, num_parents); 248 249 num = of_get_child_count(np); 250 if (!num || num > (PROG_ID_MAX + 1)) 251 return; 252 253 regmap = syscon_node_to_regmap(of_get_parent(np)); 254 if (IS_ERR(regmap)) 255 return; 256 257 for_each_child_of_node(np, progclknp) { 258 if (of_property_read_u32(progclknp, "reg", &id)) 259 continue; 260 261 if (of_property_read_string(np, "clock-output-names", &name)) 262 name = progclknp->name; 263 264 hw = at91_clk_register_programmable(regmap, name, 265 parent_names, num_parents, 266 id, layout); 267 if (IS_ERR(hw)) 268 continue; 269 270 of_clk_add_hw_provider(progclknp, of_clk_hw_simple_get, hw); 271 } 272 } 273 274 275 static void __init of_at91rm9200_clk_prog_setup(struct device_node *np) 276 { 277 of_at91_clk_prog_setup(np, &at91rm9200_programmable_layout); 278 } 279 CLK_OF_DECLARE(at91rm9200_clk_prog, "atmel,at91rm9200-clk-programmable", 280 of_at91rm9200_clk_prog_setup); 281 282 static void __init of_at91sam9g45_clk_prog_setup(struct device_node *np) 283 { 284 of_at91_clk_prog_setup(np, &at91sam9g45_programmable_layout); 285 } 286 CLK_OF_DECLARE(at91sam9g45_clk_prog, "atmel,at91sam9g45-clk-programmable", 287 of_at91sam9g45_clk_prog_setup); 288 289 static void __init of_at91sam9x5_clk_prog_setup(struct device_node *np) 290 { 291 of_at91_clk_prog_setup(np, &at91sam9x5_programmable_layout); 292 } 293 CLK_OF_DECLARE(at91sam9x5_clk_prog, "atmel,at91sam9x5-clk-programmable", 294 of_at91sam9x5_clk_prog_setup); 295