LXR linux/arch/sparc/kernel/auxio

   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
  19void __iomem *auxio_register = NULL;
  20EXPORT_SYMBOL(auxio_register);
  21
  22enum auxio_type {
  23        AUXIO_TYPE_NODEV,
  24        AUXIO_TYPE_SBUS,
  25        AUXIO_TYPE_EBUS
  26};
  27
  28static enum auxio_type auxio_devtype = AUXIO_TYPE_NODEV;
  29static DEFINE_SPINLOCK(auxio_lock);
  30
  31static 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
  55static 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
  68void 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}
  76EXPORT_SYMBOL(auxio_set_led);
  77
  78static void __auxio_sbus_set_lte(int on)
  79{
  80        __auxio_set_bit(AUXIO_AUX1_LTE, on, 0);
  81}
  82
  83void 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}
  95EXPORT_SYMBOL(auxio_set_lte);
  96
  97static const struct of_device_id auxio_match[] = {
  98        {
  99                .name = "auxio",
 100        },
 101        {},
 102};
 103
 104MODULE_DEVICE_TABLE(of, auxio_match);
 105
 106static int auxio_probe(struct platform_device *dev)
 107{
 108        struct device_node *dp = dev->dev.of_node;
 109        unsigned long size;
 110
 111        if (!strcmp(dp->parent->name, "ebus")) {
 112                auxio_devtype = AUXIO_TYPE_EBUS;
 113                size = sizeof(u32);
 114        } else if (!strcmp(dp->parent->name, "sbus")) {
 115                auxio_devtype = AUXIO_TYPE_SBUS;
 116                size = 1;
 117        } else {
 118                printk("auxio: Unknown parent bus type [%s]\n",
 119                       dp->parent->name);
 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 %s\n",
 127               dp->full_name);
 128
 129        if (auxio_devtype == AUXIO_TYPE_EBUS)
 130                auxio_set_led(AUXIO_LED_ON);
 131
 132        return 0;
 133}
 134
 135static struct platform_driver auxio_driver = {
 136        .probe          = auxio_probe,
 137        .driver = {
 138                .name = "auxio",
 139                .of_match_table = auxio_match,
 140        },
 141};
 142
 143static int __init auxio_init(void)
 144{
 145        return platform_driver_register(&auxio_driver);
 146}
 147
 148/* Must be after subsys_initcall() so that busses are probed.  Must
 149 * be before device_initcall() because things like the floppy driver
 150 * need to use the AUXIO register.
 151 */
 152fs_initcall(auxio_init);
 153