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 19 struct clkops { 20 void (*enable)(struct clk *); 21 void (*disable)(struct clk *); 22 }; 23 24 struct clk { 25 const struct clkops *ops; 26 unsigned int enabled; 27 }; 28 29 #define DEFINE_CLK(_name, _ops) \ 30 struct clk clk_##_name = { \ 31 .ops = _ops, \ 32 } 33 34 static DEFINE_SPINLOCK(clocks_lock); 35 36 static void clk_gpio27_enable(struct clk *clk) 37 { 38 /* 39 * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111: 40 * (SA-1110 Developer's Manual, section 9.1.2.1) 41 */ 42 GAFR |= GPIO_32_768kHz; 43 GPDR |= GPIO_32_768kHz; 44 TUCR = TUCR_3_6864MHz; 45 } 46 47 static void clk_gpio27_disable(struct clk *clk) 48 { 49 TUCR = 0; 50 GPDR &= ~GPIO_32_768kHz; 51 GAFR &= ~GPIO_32_768kHz; 52 } 53 54 int clk_enable(struct clk *clk) 55 { 56 unsigned long flags; 57 58 if (clk) { 59 spin_lock_irqsave(&clocks_lock, flags); 60 if (clk->enabled++ == 0) 61 clk->ops->enable(clk); 62 spin_unlock_irqrestore(&clocks_lock, flags); 63 } 64 65 return 0; 66 } 67 EXPORT_SYMBOL(clk_enable); 68 69 void clk_disable(struct clk *clk) 70 { 71 unsigned long flags; 72 73 if (clk) { 74 WARN_ON(clk->enabled == 0); 75 spin_lock_irqsave(&clocks_lock, flags); 76 if (--clk->enabled == 0) 77 clk->ops->disable(clk); 78 spin_unlock_irqrestore(&clocks_lock, flags); 79 } 80 } 81 EXPORT_SYMBOL(clk_disable); 82 83 const struct clkops clk_gpio27_ops = { 84 .enable = clk_gpio27_enable, 85 .disable = clk_gpio27_disable, 86 }; 87 88 static DEFINE_CLK(gpio27, &clk_gpio27_ops); 89 90 static struct clk_lookup sa11xx_clkregs[] = { 91 CLKDEV_INIT("sa1111.0", NULL, &clk_gpio27), 92 CLKDEV_INIT("sa1100-rtc", NULL, NULL), 93 }; 94 95 static int __init sa11xx_clk_init(void) 96 { 97 clkdev_add_table(sa11xx_clkregs, ARRAY_SIZE(sa11xx_clkregs)); 98 return 0; 99 } 100 core_initcall(sa11xx_clk_init); 101