arch/avr32/mach-at32ap/clock.c

   1 /*
   2  * Clock management for AT32AP CPUs
   3  *
   4  * Copyright (C) 2006 Atmel Corporation
   5  *
   6  * Based on arch/arm/mach-at91/clock.c
   7  *   Copyright (C) 2005 David Brownell
   8  *   Copyright (C) 2005 Ivan Kokshaysky
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14 #include <linux/clk.h>
  15 #include <linux/err.h>
  16 #include <linux/export.h>
  17 #include <linux/device.h>
  18 #include <linux/string.h>
  19 #include <linux/list.h>
  20
  21 #include <mach/chip.h>
  22
  23 #include "clock.h"
  24
  25 /* at32 clock list */
  26 static LIST_HEAD(at32_clock_list);
  27
  28 static DEFINE_SPINLOCK(clk_lock);
  29 static DEFINE_SPINLOCK(clk_list_lock);
  30
  31 void at32_clk_register(struct clk *clk)
  32 {
  33         spin_lock(&clk_list_lock);
  34         /* add the new item to the end of the list */
  35         list_add_tail(&clk->list, &at32_clock_list);
  36         spin_unlock(&clk_list_lock);
  37 }
  38
  39 static struct clk *__clk_get(struct device *dev, const char *id)
  40 {
  41         struct clk *clk;
  42
  43         list_for_each_entry(clk, &at32_clock_list, list) {
  44                 if (clk->dev == dev && strcmp(id, clk->name) == 0) {
  45                         return clk;
  46                 }
  47         }
  48
  49         return ERR_PTR(-ENOENT);
  50 }
  51
  52 struct clk *clk_get(struct device *dev, const char *id)
  53 {
  54         struct clk *clk;
  55
  56         spin_lock(&clk_list_lock);
  57         clk = __clk_get(dev, id);
  58         spin_unlock(&clk_list_lock);
  59
  60         return clk;
  61 }
  62
  63 EXPORT_SYMBOL(clk_get);
  64
  65 void clk_put(struct clk *clk)
  66 {
  67         /* clocks are static for now, we can't free them */
  68 }
  69 EXPORT_SYMBOL(clk_put);
  70
  71 static void __clk_enable(struct clk *clk)
  72 {
  73         if (clk->parent)
  74                 __clk_enable(clk->parent);
  75         if (clk->users++ == 0 && clk->mode)
  76                 clk->mode(clk, 1);
  77 }
  78
  79 int clk_enable(struct clk *clk)
  80 {
  81         unsigned long flags;
  82
  83         if (!clk)
  84                 return 0;
  85
  86         spin_lock_irqsave(&clk_lock, flags);
  87         __clk_enable(clk);
  88         spin_unlock_irqrestore(&clk_lock, flags);
  89
  90         return 0;
  91 }
  92 EXPORT_SYMBOL(clk_enable);
  93
  94 static void __clk_disable(struct clk *clk)
  95 {
  96         if (clk->users == 0) {
  97                 printk(KERN_ERR "%s: mismatched disable\n", clk->name);
  98                 WARN_ON(1);
  99                 return;
 100         }
 101
 102         if (--clk->users == 0 && clk->mode)
 103                 clk->mode(clk, 0);
 104         if (clk->parent)
 105                 __clk_disable(clk->parent);
 106 }
 107
 108 void clk_disable(struct clk *clk)
 109 {
 110         unsigned long flags;
 111
 112         if (IS_ERR_OR_NULL(clk))
 113                 return;
 114
 115         spin_lock_irqsave(&clk_lock, flags);
 116         __clk_disable(clk);
 117         spin_unlock_irqrestore(&clk_lock, flags);
 118 }
 119 EXPORT_SYMBOL(clk_disable);
 120
 121 unsigned long clk_get_rate(struct clk *clk)
 122 {
 123         unsigned long flags;
 124         unsigned long rate;
 125
 126         if (!clk)
 127                 return 0;
 128
 129         spin_lock_irqsave(&clk_lock, flags);
 130         rate = clk->get_rate(clk);
 131         spin_unlock_irqrestore(&clk_lock, flags);
 132
 133         return rate;
 134 }
 135 EXPORT_SYMBOL(clk_get_rate);
 136
 137 long clk_round_rate(struct clk *clk, unsigned long rate)
 138 {
 139         unsigned long flags, actual_rate;
 140
 141         if (!clk)
 142                 return 0;
 143
 144         if (!clk->set_rate)
 145                 return -ENOSYS;
 146
 147         spin_lock_irqsave(&clk_lock, flags);
 148         actual_rate = clk->set_rate(clk, rate, 0);
 149         spin_unlock_irqrestore(&clk_lock, flags);
 150
 151         return actual_rate;
 152 }
 153 EXPORT_SYMBOL(clk_round_rate);
 154
 155 int clk_set_rate(struct clk *clk, unsigned long rate)
 156 {
 157         unsigned long flags;
 158         long ret;
 159
 160         if (!clk)
 161                 return 0;
 162
 163         if (!clk->set_rate)
 164                 return -ENOSYS;
 165
 166         spin_lock_irqsave(&clk_lock, flags);
 167         ret = clk->set_rate(clk, rate, 1);
 168         spin_unlock_irqrestore(&clk_lock, flags);
 169
 170         return (ret < 0) ? ret : 0;
 171 }
 172 EXPORT_SYMBOL(clk_set_rate);
 173
 174 int clk_set_parent(struct clk *clk, struct clk *parent)
 175 {
 176         unsigned long flags;
 177         int ret;
 178
 179         if (!clk)
 180                 return 0;
 181
 182         if (!clk->set_parent)
 183                 return -ENOSYS;
 184
 185         spin_lock_irqsave(&clk_lock, flags);
 186         ret = clk->set_parent(clk, parent);
 187         spin_unlock_irqrestore(&clk_lock, flags);
 188
 189         return ret;
 190 }
 191 EXPORT_SYMBOL(clk_set_parent);
 192
 193 struct clk *clk_get_parent(struct clk *clk)
 194 {
 195         return !clk ? NULL : clk->parent;
 196 }
 197 EXPORT_SYMBOL(clk_get_parent);
 198
 199
 200
 201 #ifdef CONFIG_DEBUG_FS
 202
 203 /* /sys/kernel/debug/at32ap_clk */
 204
 205 #include <linux/io.h>
 206 #include <linux/debugfs.h>
 207 #include <linux/seq_file.h>
 208 #include "pm.h"
 209
 210
 211 #define NEST_DELTA      2
 212 #define NEST_MAX        6
 213
 214 struct clkinf {
 215         struct seq_file *s;
 216         unsigned        nest;
 217 };
 218
 219 static void
 220 dump_clock(struct clk *parent, struct clkinf *r)
 221 {
 222         unsigned        nest = r->nest;
 223         char            buf[16 + NEST_MAX];
 224         struct clk      *clk;
 225         unsigned        i;
 226
 227         /* skip clocks coupled to devices that aren't registered */
 228         if (parent->dev && !dev_name(parent->dev) && !parent->users)
 229                 return;
 230
 231         /* <nest spaces> name <pad to end> */
 232         memset(buf, ' ', sizeof(buf) - 1);
 233         buf[sizeof(buf) - 1] = 0;
 234         i = strlen(parent->name);
 235         memcpy(buf + nest, parent->name,
 236                         min(i, (unsigned)(sizeof(buf) - 1 - nest)));
 237
 238         seq_printf(r->s, "%s%c users=%2d %-3s %9ld Hz",
 239                 buf, parent->set_parent ? '*' : ' ',
 240                 parent->users,
 241                 parent->users ? "on" : "off",   /* NOTE: not-paranoid!! */
 242                 clk_get_rate(parent));
 243         if (parent->dev)
 244                 seq_printf(r->s, ", for %s", dev_name(parent->dev));
 245         seq_printf(r->s, "\n");
 246
 247         /* cost of this scan is small, but not linear... */
 248         r->nest = nest + NEST_DELTA;
 249
 250         list_for_each_entry(clk, &at32_clock_list, list) {
 251                 if (clk->parent == parent)
 252                         dump_clock(clk, r);
 253         }
 254         r->nest = nest;
 255 }
 256
 257 static int clk_show(struct seq_file *s, void *unused)
 258 {
 259         struct clkinf   r;
 260         int             i;
 261         struct clk      *clk;
 262
 263         /* show all the power manager registers */
 264         seq_printf(s, "MCCTRL  = %8x\n", pm_readl(MCCTRL));
 265         seq_printf(s, "CKSEL   = %8x\n", pm_readl(CKSEL));
 266         seq_printf(s, "CPUMASK = %8x\n", pm_readl(CPU_MASK));
 267         seq_printf(s, "HSBMASK = %8x\n", pm_readl(HSB_MASK));
 268         seq_printf(s, "PBAMASK = %8x\n", pm_readl(PBA_MASK));
 269         seq_printf(s, "PBBMASK = %8x\n", pm_readl(PBB_MASK));
 270         seq_printf(s, "PLL0    = %8x\n", pm_readl(PLL0));
 271         seq_printf(s, "PLL1    = %8x\n", pm_readl(PLL1));
 272         seq_printf(s, "IMR     = %8x\n", pm_readl(IMR));
 273         for (i = 0; i < 8; i++) {
 274                 if (i == 5)
 275                         continue;
 276                 seq_printf(s, "GCCTRL%d = %8x\n", i, pm_readl(GCCTRL(i)));
 277         }
 278
 279         seq_printf(s, "\n");
 280
 281         r.s = s;
 282         r.nest = 0;
 283         /* protected from changes on the list while dumping */
 284         spin_lock(&clk_list_lock);
 285
 286         /* show clock tree as derived from the three oscillators */
 287         clk = __clk_get(NULL, "osc32k");
 288         dump_clock(clk, &r);
 289         clk_put(clk);
 290
 291         clk = __clk_get(NULL, "osc0");
 292         dump_clock(clk, &r);
 293         clk_put(clk);
 294
 295         clk = __clk_get(NULL, "osc1");
 296         dump_clock(clk, &r);
 297         clk_put(clk);
 298
 299         spin_unlock(&clk_list_lock);
 300
 301         return 0;
 302 }
 303
 304 static int clk_open(struct inode *inode, struct file *file)
 305 {
 306         return single_open(file, clk_show, NULL);
 307 }
 308
 309 static const struct file_operations clk_operations = {
 310         .open           = clk_open,
 311         .read           = seq_read,
 312         .llseek         = seq_lseek,
 313         .release        = single_release,
 314 };
 315
 316 static int __init clk_debugfs_init(void)
 317 {
 318         (void) debugfs_create_file("at32ap_clk", S_IFREG | S_IRUGO,
 319                         NULL, NULL, &clk_operations);
 320
 321         return 0;
 322 }
 323 postcore_initcall(clk_debugfs_init);
 324
 325 #endif