arch/sparc/kernel/auxio_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* auxio.c: Probing for the Sparc AUXIO register at boot time.
   3  *
   4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   5  *
   6  * Refactoring for unified NCR/PCIO support 2002 Eric Brower (ebrower@usa.net)
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/ioport.h>
  13 #include <linux/of_device.h>
  14
  15 #include <asm/prom.h>
  16 #include <asm/io.h>
  17 #include <asm/auxio.h>
  18
  19 void __iomem *auxio_register = NULL;
  20 EXPORT_SYMBOL(auxio_register);
  21
  22 enum auxio_type {
  23         AUXIO_TYPE_NODEV,
  24         AUXIO_TYPE_SBUS,
  25         AUXIO_TYPE_EBUS
  26 };
  27
  28 static enum auxio_type auxio_devtype = AUXIO_TYPE_NODEV;
  29 static DEFINE_SPINLOCK(auxio_lock);
  30
  31 static void __auxio_rmw(u8 bits_on, u8 bits_off, int ebus)
  32 {
  33         if (auxio_register) {
  34                 unsigned long flags;
  35                 u8 regval, newval;
  36
  37                 spin_lock_irqsave(&auxio_lock, flags);
  38
  39                 regval = (ebus ?
  40                           (u8) readl(auxio_register) :
  41                           sbus_readb(auxio_register));
  42                 newval =  regval | bits_on;
  43                 newval &= ~bits_off;
  44                 if (!ebus)
  45                         newval &= ~AUXIO_AUX1_MASK;
  46                 if (ebus)
  47                         writel((u32) newval, auxio_register);
  48                 else
  49                         sbus_writeb(newval, auxio_register);
  50
  51                 spin_unlock_irqrestore(&auxio_lock, flags);
  52         }
  53 }
  54
  55 static void __auxio_set_bit(u8 bit, int on, int ebus)
  56 {
  57         u8 bits_on = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
  58         u8 bits_off = 0;
  59
  60         if (!on) {
  61                 u8 tmp = bits_off;
  62                 bits_off = bits_on;
  63                 bits_on = tmp;
  64         }
  65         __auxio_rmw(bits_on, bits_off, ebus);
  66 }
  67
  68 void auxio_set_led(int on)
  69 {
  70         int ebus = auxio_devtype == AUXIO_TYPE_EBUS;
  71         u8 bit;
  72
  73         bit = (ebus ? AUXIO_PCIO_LED : AUXIO_AUX1_LED);
  74         __auxio_set_bit(bit, on, ebus);
  75 }
  76 EXPORT_SYMBOL(auxio_set_led);
  77
  78 static void __auxio_sbus_set_lte(int on)
  79 {
  80         __auxio_set_bit(AUXIO_AUX1_LTE, on, 0);
  81 }
  82
  83 void auxio_set_lte(int on)
  84 {
  85         switch(auxio_devtype) {
  86         case AUXIO_TYPE_SBUS:
  87                 __auxio_sbus_set_lte(on);
  88                 break;
  89         case AUXIO_TYPE_EBUS:
  90                 /* FALL-THROUGH */
  91         default:
  92                 break;
  93         }
  94 }
  95 EXPORT_SYMBOL(auxio_set_lte);
  96
  97 static const struct of_device_id auxio_match[] = {
  98         {
  99                 .name = "auxio",
 100         },
 101         {},
 102 };
 103
 104 MODULE_DEVICE_TABLE(of, auxio_match);
 105
 106 static int auxio_probe(struct platform_device *dev)
 107 {
 108         struct device_node *dp = dev->dev.of_node;
 109         unsigned long size;
 110
 111         if (of_node_name_eq(dp->parent, "ebus")) {
 112                 auxio_devtype = AUXIO_TYPE_EBUS;
 113                 size = sizeof(u32);
 114         } else if (of_node_name_eq(dp->parent, "sbus")) {
 115                 auxio_devtype = AUXIO_TYPE_SBUS;
 116                 size = 1;
 117         } else {
 118                 printk("auxio: Unknown parent bus type [%pOFn]\n",
 119                        dp->parent);
 120                 return -ENODEV;
 121         }
 122         auxio_register = of_ioremap(&dev->resource[0], 0, size, "auxio");
 123         if (!auxio_register)
 124                 return -ENODEV;
 125
 126         printk(KERN_INFO "AUXIO: Found device at %pOF\n", dp);
 127
 128         if (auxio_devtype == AUXIO_TYPE_EBUS)
 129                 auxio_set_led(AUXIO_LED_ON);
 130
 131         return 0;
 132 }
 133
 134 static struct platform_driver auxio_driver = {
 135         .probe          = auxio_probe,
 136         .driver = {
 137                 .name = "auxio",
 138                 .of_match_table = auxio_match,
 139         },
 140 };
 141
 142 static int __init auxio_init(void)
 143 {
 144         return platform_driver_register(&auxio_driver);
 145 }
 146
 147 /* Must be after subsys_initcall() so that busses are probed.  Must
 148  * be before device_initcall() because things like the floppy driver
 149  * need to use the AUXIO register.
 150  */
 151 fs_initcall(auxio_init);