target/linux/ifxmips/files/arch/mips/ifxmips/danube/ebu.c

   1 #include <linux/init.h>
   2 #include <linux/module.h>
   3 #include <linux/types.h>
   4 #include <linux/platform_device.h>
   5 #include <linux/mutex.h>
   6 #include <linux/gpio.h>
   7
   8 #include <ifxmips.h>
   9 #include <ifxmips_ebu.h>
  10
  11 #define IFXMIPS_EBU_BUSCON      0x1e7ff
  12 #define IFXMIPS_EBU_WP          0x80000000
  13
  14 static int shadow = 0;
  15 static void __iomem *virt;
  16
  17 static int
  18 ifxmips_ebu_direction_output(struct gpio_chip *chip, unsigned offset, int value)
  19 {
  20         return 0;
  21 }
  22
  23 static void
  24 ifxmips_ebu_set(struct gpio_chip *chip, unsigned offset, int value)
  25 {
  26         unsigned long flags;
  27         if(value)
  28                 shadow |= (1 << offset);
  29         else
  30                 shadow &= ~(1 << offset);
  31         spin_lock_irqsave(&ebu_lock, flags);
  32         ifxmips_w32(IFXMIPS_EBU_BUSCON, IFXMIPS_EBU_BUSCON1);
  33         *((__u16*)virt) = shadow;
  34         ifxmips_w32(IFXMIPS_EBU_BUSCON | IFXMIPS_EBU_WP, IFXMIPS_EBU_BUSCON1);
  35         spin_unlock_irqrestore(&ebu_lock, flags);
  36 }
  37
  38 static struct gpio_chip
  39 ifxmips_ebu_chip =
  40 {
  41         .label = "ifxmips_ebu",
  42         .direction_output = ifxmips_ebu_direction_output,
  43         .set = ifxmips_ebu_set,
  44         .base = 32,
  45         .ngpio = 16,
  46         .can_sleep = 1,
  47         .owner = THIS_MODULE,
  48 };
  49
  50 static int __devinit
  51 ifxmips_ebu_probe(struct platform_device *pdev)
  52 {
  53         ifxmips_w32(pdev->resource->start | 0x1, IFXMIPS_EBU_ADDRSEL1);
  54         ifxmips_w32(IFXMIPS_EBU_BUSCON | IFXMIPS_EBU_WP, IFXMIPS_EBU_BUSCON1);
  55         virt = ioremap_nocache(pdev->resource->start, pdev->resource->end);
  56         if(gpiochip_add(&ifxmips_ebu_chip))
  57                 return -EINVAL;
  58         shadow = (int) pdev->dev.platform_data;
  59         printk("IFXMIPS: ebu-gpio loaded\n");
  60         return 0;
  61 }
  62
  63 static int
  64 ifxmips_ebu_remove(struct platform_device *dev)
  65 {
  66         return gpiochip_remove(&ifxmips_ebu_chip);
  67 }
  68
  69 static struct platform_driver
  70 ifxmips_ebu_driver = {
  71         .probe = ifxmips_ebu_probe,
  72         .remove = ifxmips_ebu_remove,
  73         .driver = {
  74                 .name = "ifxmips_ebu",
  75                 .owner = THIS_MODULE,
  76         },
  77 };
  78
  79 static int __init
  80 ifxmips_ebu_init(void)
  81 {
  82         return platform_driver_register(&ifxmips_ebu_driver);
  83 }
  84
  85 static void __exit
  86 ifxmips_ebu_exit(void)
  87 {
  88         platform_driver_unregister(&ifxmips_ebu_driver);
  89 }
  90
  91 module_init(ifxmips_ebu_init);
  92 module_exit(ifxmips_ebu_exit);
  93
  94 MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
  95 MODULE_LICENSE("GPL v2");
  96 MODULE_DESCRIPTION("ifxmips - EBU Latch GPIO-Expander");