xref: /openbmc/linux/arch/sh/kernel/cpu/irq/ipr.c (revision 22246614)
1 /*
2  * Interrupt handling for IPR-based IRQ.
3  *
4  * Copyright (C) 1999  Niibe Yutaka & Takeshi Yaegashi
5  * Copyright (C) 2000  Kazumoto Kojima
6  * Copyright (C) 2003  Takashi Kusuda <kusuda-takashi@hitachi-ul.co.jp>
7  * Copyright (C) 2006  Paul Mundt
8  *
9  * Supported system:
10  *	On-chip supporting modules (TMU, RTC, etc.).
11  *	On-chip supporting modules for SH7709/SH7709A/SH7729.
12  *	Hitachi SolutionEngine external I/O:
13  *		MS7709SE01, MS7709ASE01, and MS7750SE01
14  *
15  * This file is subject to the terms and conditions of the GNU General Public
16  * License.  See the file "COPYING" in the main directory of this archive
17  * for more details.
18  */
19 #include <linux/init.h>
20 #include <linux/irq.h>
21 #include <linux/module.h>
22 #include <linux/io.h>
23 #include <linux/interrupt.h>
24 
25 static inline struct ipr_desc *get_ipr_desc(unsigned int irq)
26 {
27 	struct irq_chip *chip = get_irq_chip(irq);
28 	return (void *)((char *)chip - offsetof(struct ipr_desc, chip));
29 }
30 
31 static void disable_ipr_irq(unsigned int irq)
32 {
33 	struct ipr_data *p = get_irq_chip_data(irq);
34 	unsigned long addr = get_ipr_desc(irq)->ipr_offsets[p->ipr_idx];
35 	/* Set the priority in IPR to 0 */
36 	ctrl_outw(ctrl_inw(addr) & (0xffff ^ (0xf << p->shift)), addr);
37 }
38 
39 static void enable_ipr_irq(unsigned int irq)
40 {
41 	struct ipr_data *p = get_irq_chip_data(irq);
42 	unsigned long addr = get_ipr_desc(irq)->ipr_offsets[p->ipr_idx];
43 	/* Set priority in IPR back to original value */
44 	ctrl_outw(ctrl_inw(addr) | (p->priority << p->shift), addr);
45 }
46 
47 /*
48  * The shift value is now the number of bits to shift, not the number of
49  * bits/4. This is to make it easier to read the value directly from the
50  * datasheets. The IPR address is calculated using the ipr_offset table.
51  */
52 void register_ipr_controller(struct ipr_desc *desc)
53 {
54 	int i;
55 
56 	desc->chip.mask = disable_ipr_irq;
57 	desc->chip.unmask = enable_ipr_irq;
58 	desc->chip.mask_ack = disable_ipr_irq;
59 
60 	for (i = 0; i < desc->nr_irqs; i++) {
61 		struct ipr_data *p = desc->ipr_data + i;
62 
63 		BUG_ON(p->ipr_idx >= desc->nr_offsets);
64 		BUG_ON(!desc->ipr_offsets[p->ipr_idx]);
65 
66 		disable_irq_nosync(p->irq);
67 		set_irq_chip_and_handler_name(p->irq, &desc->chip,
68 				      handle_level_irq, "level");
69 		set_irq_chip_data(p->irq, p);
70 		disable_ipr_irq(p->irq);
71 	}
72 }
73 EXPORT_SYMBOL(register_ipr_controller);
74