powerpc/sysdev/i8259.c

1 // SPDX-License-Identifier: GPL-2.0-or-later
27  * acknowledge feature or poll.  How i8259_init() is called determines
28  * which is called.  It should be noted that polling is broken on some
29  * IBM and Motorola PReP boxes so we must use the int-ack feature on them.
36 	/* Either int-ack or poll for the IRQ */  in i8259_irq()
43 		/* Perform an interrupt acknowledge cycle on controller 1. */  in i8259_irq()
44 		outb(0x0C, 0x20);		/* prepare for poll */  in i8259_irq()
49 			 * acknowledge on controller 2.  in i8259_irq()
51 			outb(0x0C, 0xA0);	/* prepare for poll */  in i8259_irq()
61 		 * significant bit is not set then there is no valid  in i8259_irq()
81 	if (d->irq > 7) {  in i8259_mask_and_ack_irq()
82 		cached_A1 |= 1 << (d->irq-8);  in i8259_mask_and_ack_irq()
85 		outb(0x20, 0xA0);	/* Non-specific EOI */  in i8259_mask_and_ack_irq()
86 		outb(0x20, 0x20);	/* Non-specific EOI to cascade */  in i8259_mask_and_ack_irq()
88 		cached_21 |= 1 << d->irq;  in i8259_mask_and_ack_irq()
91 		outb(0x20, 0x20);	/* Non-specific EOI */  in i8259_mask_and_ack_irq()
106 	pr_debug("i8259_mask_irq(%d)\n", d->irq);  in i8259_mask_irq()
109 	if (d->irq < 8)  in i8259_mask_irq()
110 		cached_21 |= 1 << d->irq;  in i8259_mask_irq()
112 		cached_A1 |= 1 << (d->irq-8);  in i8259_mask_irq()
113 	i8259_set_irq_mask(d->irq);  in i8259_mask_irq()
121 	pr_debug("i8259_unmask_irq(%d)\n", d->irq);  in i8259_unmask_irq()
124 	if (d->irq < 8)  in i8259_unmask_irq()
125 		cached_21 &= ~(1 << d->irq);  in i8259_unmask_irq()
127 		cached_A1 &= ~(1 << (d->irq-8));  in i8259_unmask_irq()
128 	i8259_set_irq_mask(d->irq);  in i8259_unmask_irq()
217  * i8259_init - Initialize the legacy controller
234 	/* init master interrupt controller */  in i8259_init()
235 	outb(0x11, 0x20); /* Start init sequence */  in i8259_init()
237 	outb(0x04, 0x21); /* edge triggered, Cascade (slave) on IRQ2 */  in i8259_init()
240 	/* init slave interrupt controller */  in i8259_init()
241 	outb(0x11, 0xA0); /* Start init sequence */  in i8259_init()
243 	outb(0x02, 0xA1); /* edge triggered, Cascade (slave) on IRQ2 */  in i8259_init()