arch/arm/mach-sa1100/clock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/arch/arm/mach-sa1100/clock.c
   4  */
   5 #include <linux/module.h>
   6 #include <linux/kernel.h>
   7 #include <linux/device.h>
   8 #include <linux/list.h>
   9 #include <linux/errno.h>
  10 #include <linux/err.h>
  11 #include <linux/string.h>
  12 #include <linux/clk.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/mutex.h>
  15 #include <linux/io.h>
  16 #include <linux/clkdev.h>
  17
  18 #include <mach/hardware.h>
  19 #include <mach/generic.h>
  20
  21 struct clkops {
  22         void                    (*enable)(struct clk *);
  23         void                    (*disable)(struct clk *);
  24         unsigned long           (*get_rate)(struct clk *);
  25 };
  26
  27 struct clk {
  28         const struct clkops     *ops;
  29         unsigned int            enabled;
  30 };
  31
  32 #define DEFINE_CLK(_name, _ops)                         \
  33 struct clk clk_##_name = {                              \
  34                 .ops    = _ops,                         \
  35         }
  36
  37 static DEFINE_SPINLOCK(clocks_lock);
  38
  39 /* Dummy clk routine to build generic kernel parts that may be using them */
  40 long clk_round_rate(struct clk *clk, unsigned long rate)
  41 {
  42         return clk_get_rate(clk);
  43 }
  44 EXPORT_SYMBOL(clk_round_rate);
  45
  46 int clk_set_rate(struct clk *clk, unsigned long rate)
  47 {
  48         return 0;
  49 }
  50 EXPORT_SYMBOL(clk_set_rate);
  51
  52 int clk_set_parent(struct clk *clk, struct clk *parent)
  53 {
  54         return 0;
  55 }
  56 EXPORT_SYMBOL(clk_set_parent);
  57
  58 struct clk *clk_get_parent(struct clk *clk)
  59 {
  60         return NULL;
  61 }
  62 EXPORT_SYMBOL(clk_get_parent);
  63
  64 static void clk_gpio27_enable(struct clk *clk)
  65 {
  66         /*
  67          * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
  68          * (SA-1110 Developer's Manual, section 9.1.2.1)
  69          */
  70         GAFR |= GPIO_32_768kHz;
  71         GPDR |= GPIO_32_768kHz;
  72         TUCR = TUCR_3_6864MHz;
  73 }
  74
  75 static void clk_gpio27_disable(struct clk *clk)
  76 {
  77         TUCR = 0;
  78         GPDR &= ~GPIO_32_768kHz;
  79         GAFR &= ~GPIO_32_768kHz;
  80 }
  81
  82 static void clk_cpu_enable(struct clk *clk)
  83 {
  84 }
  85
  86 static void clk_cpu_disable(struct clk *clk)
  87 {
  88 }
  89
  90 static unsigned long clk_cpu_get_rate(struct clk *clk)
  91 {
  92         return sa11x0_getspeed(0) * 1000;
  93 }
  94
  95 int clk_enable(struct clk *clk)
  96 {
  97         unsigned long flags;
  98
  99         if (clk) {
 100                 spin_lock_irqsave(&clocks_lock, flags);
 101                 if (clk->enabled++ == 0)
 102                         clk->ops->enable(clk);
 103                 spin_unlock_irqrestore(&clocks_lock, flags);
 104         }
 105
 106         return 0;
 107 }
 108 EXPORT_SYMBOL(clk_enable);
 109
 110 void clk_disable(struct clk *clk)
 111 {
 112         unsigned long flags;
 113
 114         if (clk) {
 115                 WARN_ON(clk->enabled == 0);
 116                 spin_lock_irqsave(&clocks_lock, flags);
 117                 if (--clk->enabled == 0)
 118                         clk->ops->disable(clk);
 119                 spin_unlock_irqrestore(&clocks_lock, flags);
 120         }
 121 }
 122 EXPORT_SYMBOL(clk_disable);
 123
 124 unsigned long clk_get_rate(struct clk *clk)
 125 {
 126         if (clk && clk->ops && clk->ops->get_rate)
 127                 return clk->ops->get_rate(clk);
 128
 129         return 0;
 130 }
 131 EXPORT_SYMBOL(clk_get_rate);
 132
 133 const struct clkops clk_gpio27_ops = {
 134         .enable         = clk_gpio27_enable,
 135         .disable        = clk_gpio27_disable,
 136 };
 137
 138 const struct clkops clk_cpu_ops = {
 139         .enable         = clk_cpu_enable,
 140         .disable        = clk_cpu_disable,
 141         .get_rate       = clk_cpu_get_rate,
 142 };
 143
 144 static DEFINE_CLK(gpio27, &clk_gpio27_ops);
 145
 146 static DEFINE_CLK(cpu, &clk_cpu_ops);
 147
 148 static unsigned long clk_36864_get_rate(struct clk *clk)
 149 {
 150         return 3686400;
 151 }
 152
 153 static struct clkops clk_36864_ops = {
 154         .enable         = clk_cpu_enable,
 155         .disable        = clk_cpu_disable,
 156         .get_rate       = clk_36864_get_rate,
 157 };
 158
 159 static DEFINE_CLK(36864, &clk_36864_ops);
 160
 161 static struct clk_lookup sa11xx_clkregs[] = {
 162         CLKDEV_INIT("sa1111.0", NULL, &clk_gpio27),
 163         CLKDEV_INIT("sa1100-rtc", NULL, NULL),
 164         CLKDEV_INIT("sa11x0-fb", NULL, &clk_cpu),
 165         CLKDEV_INIT("sa11x0-pcmcia", NULL, &clk_cpu),
 166         /* sa1111 names devices using internal offsets, PCMCIA is at 0x1800 */
 167         CLKDEV_INIT("1800", NULL, &clk_cpu),
 168         CLKDEV_INIT(NULL, "OSTIMER0", &clk_36864),
 169 };
 170
 171 int __init sa11xx_clk_init(void)
 172 {
 173         clkdev_add_table(sa11xx_clkregs, ARRAY_SIZE(sa11xx_clkregs));
 174         return 0;
 175 }