package/lqtapi/src/mps/vmmc-module.c

   1 #include <linux/module.h>
   2 #include <linux/kernel.h>
   3 #include <linux/slab.h>
   4 #include <linux/mutex.h>
   5
   6 #include <asm/bitops.h>
   7
   8 #include "vmmc-module.h"
   9
  10 int vmmc_module_init(struct vmmc_module *module, size_t num_pins,
  11         const struct vmmc_module_ops *ops)
  12 {
  13         module->pins = kcalloc(num_pins, sizeof(*module->pins), GFP_KERNEL);
  14
  15         if (!module->pins)
  16                 return -ENOMEM;
  17
  18         module->num_pins = num_pins;
  19         module->ops = ops;
  20
  21         mutex_init(&module->lock);
  22         module->refcount = 0;
  23
  24         return 0;
  25 }
  26
  27 int vmmc_module_sync(struct vmmc_module *module)
  28 {
  29         if (!test_and_clear_bit(VMMC_MODULE_FLAG_MODIFIED, &module->flags))
  30                 return 0;
  31
  32         return module->ops->sync(module);
  33 }
  34
  35 int vmmc_module_get_pin(struct vmmc_module *module)
  36 {
  37         size_t i = 0;
  38         int ret = 0;
  39
  40         for (i = 0; i < module->num_pins; ++i) {
  41                 if (!test_and_set_bit(VMMC_MODULE_FLAG_PIN_USED(i), &module->flags))
  42                         break;
  43         }
  44         if (i == module->num_pins)
  45                 ret = -EBUSY;
  46         else
  47                 ret = i;
  48
  49         return ret;
  50 }
  51
  52 void vmmc_module_put_pin(struct vmmc_module *module, unsigned int pin)
  53 {
  54         module->pins[pin] = 0;
  55         clear_bit(VMMC_MODULE_FLAG_PIN_USED(pin), &module->flags);
  56 }
  57
  58 void vmmc_module_set_pin_input(struct vmmc_module *module, unsigned int pin,
  59         struct vmmc_module *input)
  60 {
  61         if (input)
  62                 module->pins[pin] = input->id;
  63         else
  64                 module->pins[pin] = 0;
  65
  66         set_bit(VMMC_MODULE_FLAG_MODIFIED, &module->flags);
  67 }
  68
  69 static void vmmc_module_enable(struct vmmc_module *module)
  70 {
  71         mutex_lock(&module->lock);
  72
  73         if (++module->refcount == 1)
  74                 module->ops->enable(module, true);
  75
  76         mutex_unlock(&module->lock);
  77 }
  78
  79 static void vmmc_module_disable(struct vmmc_module *module)
  80 {
  81         mutex_lock(&module->lock);
  82
  83         if (module->refcount <= 0)
  84                 printk(KERN_ERR "vmmc module: unbalanced disable\n");
  85         else if (--module->refcount == 0)
  86                 module->ops->enable(module, false);
  87
  88         mutex_unlock(&module->lock);
  89 }
  90
  91
  92 unsigned int vmmc_link_init(struct vmmc_link *link,
  93         struct vmmc_module *a, struct vmmc_module *b)
  94 {
  95         link->pins[0] = vmmc_module_get_pin(a);
  96         link->pins[1] = vmmc_module_get_pin(b);
  97         link->modules[0] = a;
  98         link->modules[1] = b;
  99
 100         return 0;
 101 }
 102
 103 void vmmc_link_put(struct vmmc_link *link)
 104 {
 105         vmmc_link_disable(link);
 106         vmmc_module_sync(link->modules[0]);
 107         vmmc_module_sync(link->modules[1]);
 108         vmmc_module_put_pin(link->modules[0], link->pins[0]);
 109         vmmc_module_put_pin(link->modules[1], link->pins[1]);
 110 }
 111
 112 void vmmc_link_enable(struct vmmc_link *link)
 113 {
 114         vmmc_module_set_pin_input(link->modules[0], link->pins[0],
 115                 link->modules[1]);
 116         vmmc_module_set_pin_input(link->modules[1], link->pins[1],
 117                 link->modules[0]);
 118
 119         vmmc_module_enable(link->modules[0]);
 120         vmmc_module_enable(link->modules[1]);
 121 }
 122
 123 void vmmc_link_disable(struct vmmc_link *link)
 124 {
 125         vmmc_module_set_pin_input(link->modules[0], link->pins[0], NULL);
 126         vmmc_module_set_pin_input(link->modules[1], link->pins[1], NULL);
 127
 128         vmmc_module_disable(link->modules[0]);
 129         vmmc_module_disable(link->modules[1]);
 130 }