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); 152