arch/arm/mach-sa1100/clock.c

   1 /*
   2  *  linux/arch/arm/mach-sa1100/clock.c
   3  */
   4 #include <linux/module.h>
   5 #include <linux/kernel.h>
   6 #include <linux/device.h>
   7 #include <linux/list.h>
   8 #include <linux/errno.h>
   9 #include <linux/err.h>
  10 #include <linux/string.h>
  11 #include <linux/clk.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/mutex.h>
  14 #include <linux/io.h>
  15 #include <linux/clkdev.h>
  16
  17 #include <mach/hardware.h>
  18 #include <mach/generic.h>
  19
  20 struct clkops {
  21         void                    (*enable)(struct clk *);
  22         void                    (*disable)(struct clk *);
  23         unsigned long           (*get_rate)(struct clk *);
  24 };
  25
  26 struct clk {
  27         const struct clkops     *ops;
  28         unsigned int            enabled;
  29 };
  30
  31 #define DEFINE_CLK(_name, _ops)                         \
  32 struct clk clk_##_name = {                              \
  33                 .ops    = _ops,                         \
  34         }
  35
  36 static DEFINE_SPINLOCK(clocks_lock);
  37
  38 /* Dummy clk routine to build generic kernel parts that may be using them */
  39 long clk_round_rate(struct clk *clk, unsigned long rate)
  40 {
  41         return clk_get_rate(clk);
  42 }
  43 EXPORT_SYMBOL(clk_round_rate);
  44
  45 int clk_set_rate(struct clk *clk, unsigned long rate)
  46 {
  47         return 0;
  48 }
  49 EXPORT_SYMBOL(clk_set_rate);
  50
  51 int clk_set_parent(struct clk *clk, struct clk *parent)
  52 {
  53         return 0;
  54 }
  55 EXPORT_SYMBOL(clk_set_parent);
  56
  57 struct clk *clk_get_parent(struct clk *clk)
  58 {
  59         return NULL;
  60 }
  61 EXPORT_SYMBOL(clk_get_parent);
  62
  63 static void clk_gpio27_enable(struct clk *clk)
  64 {
  65         /*
  66          * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
  67          * (SA-1110 Developer's Manual, section 9.1.2.1)
  68          */
  69         GAFR |= GPIO_32_768kHz;
  70         GPDR |= GPIO_32_768kHz;
  71         TUCR = TUCR_3_6864MHz;
  72 }
  73
  74 static void clk_gpio27_disable(struct clk *clk)
  75 {
  76         TUCR = 0;
  77         GPDR &= ~GPIO_32_768kHz;
  78         GAFR &= ~GPIO_32_768kHz;
  79 }
  80
  81 static void clk_cpu_enable(struct clk *clk)
  82 {
  83 }
  84
  85 static void clk_cpu_disable(struct clk *clk)
  86 {
  87 }
  88
  89 static unsigned long clk_cpu_get_rate(struct clk *clk)
  90 {
  91         return sa11x0_getspeed(0) * 1000;
  92 }
  93
  94 int clk_enable(struct clk *clk)
  95 {
  96         unsigned long flags;
  97
  98         if (clk) {
  99                 spin_lock_irqsave(&clocks_lock, flags);
 100                 if (clk->enabled++ == 0)
 101                         clk->ops->enable(clk);
 102                 spin_unlock_irqrestore(&clocks_lock, flags);
 103         }
 104
 105         return 0;
 106 }
 107 EXPORT_SYMBOL(clk_enable);
 108
 109 void clk_disable(struct clk *clk)
 110 {
 111         unsigned long flags;
 112
 113         if (clk) {
 114                 WARN_ON(clk->enabled == 0);
 115                 spin_lock_irqsave(&clocks_lock, flags);
 116                 if (--clk->enabled == 0)
 117                         clk->ops->disable(clk);
 118                 spin_unlock_irqrestore(&clocks_lock, flags);
 119         }
 120 }
 121 EXPORT_SYMBOL(clk_disable);
 122
 123 unsigned long clk_get_rate(struct clk *clk)
 124 {
 125         if (clk && clk->ops && clk->ops->get_rate)
 126                 return clk->ops->get_rate(clk);
 127
 128         return 0;
 129 }
 130 EXPORT_SYMBOL(clk_get_rate);
 131
 132 const struct clkops clk_gpio27_ops = {
 133         .enable         = clk_gpio27_enable,
 134         .disable        = clk_gpio27_disable,
 135 };
 136
 137 const struct clkops clk_cpu_ops = {
 138         .enable         = clk_cpu_enable,
 139         .disable        = clk_cpu_disable,
 140         .get_rate       = clk_cpu_get_rate,
 141 };
 142
 143 static DEFINE_CLK(gpio27, &clk_gpio27_ops);
 144
 145 static DEFINE_CLK(cpu, &clk_cpu_ops);
 146
 147 static unsigned long clk_36864_get_rate(struct clk *clk)
 148 {
 149         return 3686400;
 150 }
 151
 152 static struct clkops clk_36864_ops = {
 153         .enable         = clk_cpu_enable,
 154         .disable        = clk_cpu_disable,
 155         .get_rate       = clk_36864_get_rate,
 156 };
 157
 158 static DEFINE_CLK(36864, &clk_36864_ops);
 159
 160 static struct clk_lookup sa11xx_clkregs[] = {
 161         CLKDEV_INIT("sa1111.0", NULL, &clk_gpio27),
 162         CLKDEV_INIT("sa1100-rtc", NULL, NULL),
 163         CLKDEV_INIT("sa11x0-fb", NULL, &clk_cpu),
 164         CLKDEV_INIT("sa11x0-pcmcia", NULL, &clk_cpu),
 165         /* sa1111 names devices using internal offsets, PCMCIA is at 0x1800 */
 166         CLKDEV_INIT("1800", NULL, &clk_cpu),
 167         CLKDEV_INIT(NULL, "OSTIMER0", &clk_36864),
 168 };
 169
 170 int __init sa11xx_clk_init(void)
 171 {
 172         clkdev_add_table(sa11xx_clkregs, ARRAY_SIZE(sa11xx_clkregs));
 173         return 0;
 174 }