arch/i386/kernel/scx200.c

   1 /* linux/arch/i386/kernel/scx200.c
   2
   3    Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
   4
   5    National Semiconductor SCx200 support. */
   6
   7 #include <linux/config.h>
   8 #include <linux/module.h>
   9 #include <linux/errno.h>
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/pci.h>
  13
  14 #include <linux/scx200.h>
  15
  16 #define NAME "scx200"
  17
  18 MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>");
  19 MODULE_DESCRIPTION("NatSemi SCx200 Driver");
  20 MODULE_LICENSE("GPL");
  21
  22 unsigned scx200_gpio_base = 0;
  23 long scx200_gpio_shadow[2];
  24
  25 spinlock_t scx200_gpio_lock = SPIN_LOCK_UNLOCKED;
  26 static spinlock_t scx200_gpio_config_lock = SPIN_LOCK_UNLOCKED;
  27
  28 u32 scx200_gpio_configure(int index, u32 mask, u32 bits)
  29 {
  30         u32 config, new_config;
  31         unsigned long flags;
  32
  33         spin_lock_irqsave(&scx200_gpio_config_lock, flags);
  34
  35         outl(index, scx200_gpio_base + 0x20);
  36         config = inl(scx200_gpio_base + 0x24);
  37
  38         new_config = (config & mask) | bits;
  39         outl(new_config, scx200_gpio_base + 0x24);
  40
  41         spin_unlock_irqrestore(&scx200_gpio_config_lock, flags);
  42
  43         return config;
  44 }
  45
  46 void scx200_gpio_dump(unsigned index)
  47 {
  48         u32 config = scx200_gpio_configure(index, ~0, 0);
  49         printk(KERN_DEBUG "GPIO%02u: 0x%08lx", index, (unsigned long)config);
  50
  51         if (config & 1)
  52                 printk(" OE"); /* output enabled */
  53         else
  54                 printk(" TS"); /* tristate */
  55         if (config & 2)
  56                 printk(" PP"); /* push pull */
  57         else
  58                 printk(" OD"); /* open drain */
  59         if (config & 4)
  60                 printk(" PUE"); /* pull up enabled */
  61         else
  62                 printk(" PUD"); /* pull up disabled */
  63         if (config & 8)
  64                 printk(" LOCKED"); /* locked */
  65         if (config & 16)
  66                 printk(" LEVEL"); /* level input */
  67         else
  68                 printk(" EDGE"); /* edge input */
  69         if (config & 32)
  70                 printk(" HI"); /* trigger on rising edge */
  71         else
  72                 printk(" LO"); /* trigger on falling edge */
  73         if (config & 64)
  74                 printk(" DEBOUNCE"); /* debounce */
  75         printk("\n");
  76 }
  77
  78 int __init scx200_init(void)
  79 {
  80         struct pci_dev *bridge;
  81         int bank;
  82         unsigned base;
  83
  84         printk(KERN_INFO NAME ": NatSemi SCx200 Driver\n");
  85
  86         if ((bridge = pci_find_device(PCI_VENDOR_ID_NS,
  87                                       PCI_DEVICE_ID_NS_SCx200_BRIDGE,
  88                                       NULL)) == NULL
  89             && (bridge = pci_find_device(PCI_VENDOR_ID_NS,
  90                                          PCI_DEVICE_ID_NS_SC1100_BRIDGE,
  91                                          NULL)) == NULL)
  92                 return -ENODEV;
  93
  94         base = pci_resource_start(bridge, 0);
  95         printk(KERN_INFO NAME ": GPIO base 0x%x\n", base);
  96
  97         if (request_region(base, SCx200_GPIO_SIZE, "NatSemi SCx200 GPIO") == 0) {
  98                 printk(KERN_ERR NAME ": can't allocate I/O for GPIOs\n");
  99                 return -EBUSY;
 100         }
 101
 102         scx200_gpio_base = base;
 103
 104         /* read the current values driven on the GPIO signals */
 105         for (bank = 0; bank < 2; ++bank)
 106                 scx200_gpio_shadow[bank] = inl(scx200_gpio_base + 0x10 * bank);
 107
 108         return 0;
 109 }
 110
 111 void __exit scx200_cleanup(void)
 112 {
 113         release_region(scx200_gpio_base, SCx200_GPIO_SIZE);
 114 }
 115
 116 module_init(scx200_init);
 117 module_exit(scx200_cleanup);
 118
 119 EXPORT_SYMBOL(scx200_gpio_base);
 120 EXPORT_SYMBOL(scx200_gpio_shadow);
 121 EXPORT_SYMBOL(scx200_gpio_lock);
 122 EXPORT_SYMBOL(scx200_gpio_configure);
 123 EXPORT_SYMBOL(scx200_gpio_dump);
 124
 125 /*
 126     Local variables:
 127         compile-command: "make -k -C ../../.. SUBDIRS=arch/i386/kernel modules"
 128         c-basic-offset: 8
 129     End:
 130 */