arch/arm/mach-davinci/clock.c

   1 /*
   2  * TI DaVinci clock config file
   3  *
   4  * Copyright (C) 2006 Texas Instruments.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/errno.h>
  16 #include <linux/err.h>
  17 #include <linux/mutex.h>
  18 #include <linux/platform_device.h>
  19
  20 #include <mach/hardware.h>
  21 #include <asm/io.h>
  22
  23 #include <mach/psc.h>
  24 #include "clock.h"
  25
  26 /* PLL/Reset register offsets */
  27 #define PLLM            0x110
  28
  29 static LIST_HEAD(clocks);
  30 static DEFINE_MUTEX(clocks_mutex);
  31 static DEFINE_SPINLOCK(clockfw_lock);
  32
  33 static unsigned int commonrate;
  34 static unsigned int armrate;
  35 static unsigned int fixedrate = 27000000;       /* 27 MHZ */
  36
  37 extern void davinci_psc_config(unsigned int domain, unsigned int id, char enable);
  38
  39 /*
  40  * Returns a clock. Note that we first try to use device id on the bus
  41  * and clock name. If this fails, we try to use clock name only.
  42  */
  43 struct clk *clk_get(struct device *dev, const char *id)
  44 {
  45         struct clk *p, *clk = ERR_PTR(-ENOENT);
  46         int idno;
  47
  48         if (dev == NULL || dev->bus != &platform_bus_type)
  49                 idno = -1;
  50         else
  51                 idno = to_platform_device(dev)->id;
  52
  53         mutex_lock(&clocks_mutex);
  54
  55         list_for_each_entry(p, &clocks, node) {
  56                 if (p->id == idno &&
  57                     strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  58                         clk = p;
  59                         goto found;
  60                 }
  61         }
  62
  63         list_for_each_entry(p, &clocks, node) {
  64                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
  65                         clk = p;
  66                         break;
  67                 }
  68         }
  69
  70 found:
  71         mutex_unlock(&clocks_mutex);
  72
  73         return clk;
  74 }
  75 EXPORT_SYMBOL(clk_get);
  76
  77 void clk_put(struct clk *clk)
  78 {
  79         if (clk && !IS_ERR(clk))
  80                 module_put(clk->owner);
  81 }
  82 EXPORT_SYMBOL(clk_put);
  83
  84 static int __clk_enable(struct clk *clk)
  85 {
  86         if (clk->flags & ALWAYS_ENABLED)
  87                 return 0;
  88
  89         davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, clk->lpsc, 1);
  90         return 0;
  91 }
  92
  93 static void __clk_disable(struct clk *clk)
  94 {
  95         if (clk->usecount)
  96                 return;
  97
  98         davinci_psc_config(DAVINCI_GPSC_ARMDOMAIN, clk->lpsc, 0);
  99 }
 100
 101 int clk_enable(struct clk *clk)
 102 {
 103         unsigned long flags;
 104         int ret = 0;
 105
 106         if (clk == NULL || IS_ERR(clk))
 107                 return -EINVAL;
 108
 109         if (clk->usecount++ == 0) {
 110                 spin_lock_irqsave(&clockfw_lock, flags);
 111                 ret = __clk_enable(clk);
 112                 spin_unlock_irqrestore(&clockfw_lock, flags);
 113         }
 114
 115         return ret;
 116 }
 117 EXPORT_SYMBOL(clk_enable);
 118
 119 void clk_disable(struct clk *clk)
 120 {
 121         unsigned long flags;
 122
 123         if (clk == NULL || IS_ERR(clk))
 124                 return;
 125
 126         if (clk->usecount > 0 && !(--clk->usecount)) {
 127                 spin_lock_irqsave(&clockfw_lock, flags);
 128                 __clk_disable(clk);
 129                 spin_unlock_irqrestore(&clockfw_lock, flags);
 130         }
 131 }
 132 EXPORT_SYMBOL(clk_disable);
 133
 134 unsigned long clk_get_rate(struct clk *clk)
 135 {
 136         if (clk == NULL || IS_ERR(clk))
 137                 return -EINVAL;
 138
 139         return *(clk->rate);
 140 }
 141 EXPORT_SYMBOL(clk_get_rate);
 142
 143 long clk_round_rate(struct clk *clk, unsigned long rate)
 144 {
 145         if (clk == NULL || IS_ERR(clk))
 146                 return -EINVAL;
 147
 148         return *(clk->rate);
 149 }
 150 EXPORT_SYMBOL(clk_round_rate);
 151
 152 int clk_set_rate(struct clk *clk, unsigned long rate)
 153 {
 154         if (clk == NULL || IS_ERR(clk))
 155                 return -EINVAL;
 156
 157         /* changing the clk rate is not supported */
 158         return -EINVAL;
 159 }
 160 EXPORT_SYMBOL(clk_set_rate);
 161
 162 int clk_register(struct clk *clk)
 163 {
 164         if (clk == NULL || IS_ERR(clk))
 165                 return -EINVAL;
 166
 167         mutex_lock(&clocks_mutex);
 168         list_add(&clk->node, &clocks);
 169         mutex_unlock(&clocks_mutex);
 170
 171         return 0;
 172 }
 173 EXPORT_SYMBOL(clk_register);
 174
 175 void clk_unregister(struct clk *clk)
 176 {
 177         if (clk == NULL || IS_ERR(clk))
 178                 return;
 179
 180         mutex_lock(&clocks_mutex);
 181         list_del(&clk->node);
 182         mutex_unlock(&clocks_mutex);
 183 }
 184 EXPORT_SYMBOL(clk_unregister);
 185
 186 static struct clk davinci_clks[] = {
 187         {
 188                 .name = "ARMCLK",
 189                 .rate = &armrate,
 190                 .lpsc = -1,
 191                 .flags = ALWAYS_ENABLED,
 192         },
 193         {
 194                 .name = "UART",
 195                 .rate = &fixedrate,
 196                 .lpsc = DAVINCI_LPSC_UART0,
 197         },
 198         {
 199                 .name = "EMACCLK",
 200                 .rate = &commonrate,
 201                 .lpsc = DAVINCI_LPSC_EMAC_WRAPPER,
 202         },
 203         {
 204                 .name = "I2CCLK",
 205                 .rate = &fixedrate,
 206                 .lpsc = DAVINCI_LPSC_I2C,
 207         },
 208         {
 209                 .name = "IDECLK",
 210                 .rate = &commonrate,
 211                 .lpsc = DAVINCI_LPSC_ATA,
 212         },
 213         {
 214                 .name = "McBSPCLK",
 215                 .rate = &commonrate,
 216                 .lpsc = DAVINCI_LPSC_McBSP,
 217         },
 218         {
 219                 .name = "MMCSDCLK",
 220                 .rate = &commonrate,
 221                 .lpsc = DAVINCI_LPSC_MMC_SD,
 222         },
 223         {
 224                 .name = "SPICLK",
 225                 .rate = &commonrate,
 226                 .lpsc = DAVINCI_LPSC_SPI,
 227         },
 228         {
 229                 .name = "gpio",
 230                 .rate = &commonrate,
 231                 .lpsc = DAVINCI_LPSC_GPIO,
 232         },
 233         {
 234                 .name = "AEMIFCLK",
 235                 .rate = &commonrate,
 236                 .lpsc = DAVINCI_LPSC_AEMIF,
 237                 .usecount = 1,
 238         }
 239 };
 240
 241 int __init davinci_clk_init(void)
 242 {
 243         struct clk *clkp;
 244         int count = 0;
 245         u32 pll_mult;
 246
 247         pll_mult = davinci_readl(DAVINCI_PLL_CNTRL0_BASE + PLLM);
 248         commonrate = ((pll_mult + 1) * 27000000) / 6;
 249         armrate = ((pll_mult + 1) * 27000000) / 2;
 250
 251         for (clkp = davinci_clks; count < ARRAY_SIZE(davinci_clks);
 252              count++, clkp++) {
 253                 clk_register(clkp);
 254
 255                 /* Turn on clocks that have been enabled in the
 256                  * table above */
 257                 if (clkp->usecount)
 258                         clk_enable(clkp);
 259         }
 260
 261         return 0;
 262 }
 263
 264 #ifdef CONFIG_PROC_FS
 265 #include <linux/proc_fs.h>
 266 #include <linux/seq_file.h>
 267
 268 static void *davinci_ck_start(struct seq_file *m, loff_t *pos)
 269 {
 270         return *pos < 1 ? (void *)1 : NULL;
 271 }
 272
 273 static void *davinci_ck_next(struct seq_file *m, void *v, loff_t *pos)
 274 {
 275         ++*pos;
 276         return NULL;
 277 }
 278
 279 static void davinci_ck_stop(struct seq_file *m, void *v)
 280 {
 281 }
 282
 283 static int davinci_ck_show(struct seq_file *m, void *v)
 284 {
 285         struct clk *cp;
 286
 287         list_for_each_entry(cp, &clocks, node)
 288                 seq_printf(m,"%s %d %d\n", cp->name, *(cp->rate), cp->usecount);
 289
 290         return 0;
 291 }
 292
 293 static const struct seq_operations davinci_ck_op = {
 294         .start  = davinci_ck_start,
 295         .next   = davinci_ck_next,
 296         .stop   = davinci_ck_stop,
 297         .show   = davinci_ck_show
 298 };
 299
 300 static int davinci_ck_open(struct inode *inode, struct file *file)
 301 {
 302         return seq_open(file, &davinci_ck_op);
 303 }
 304
 305 static const struct file_operations proc_davinci_ck_operations = {
 306         .open           = davinci_ck_open,
 307         .read           = seq_read,
 308         .llseek         = seq_lseek,
 309         .release        = seq_release,
 310 };
 311
 312 static int __init davinci_ck_proc_init(void)
 313 {
 314         proc_create("davinci_clocks", 0, NULL, &proc_davinci_ck_operations);
 315         return 0;
 316
 317 }
 318 __initcall(davinci_ck_proc_init);
 319 #endif  /* CONFIG_DEBUG_PROC_FS */