xref: /openbmc/linux/arch/sh/kernel/cpu/irq/ipr.c (revision 82e6fdd6)
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/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/irq.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/topology.h>
26 
27 static inline struct ipr_desc *get_ipr_desc(struct irq_data *data)
28 {
29 	struct irq_chip *chip = irq_data_get_irq_chip(data);
30 	return container_of(chip, struct ipr_desc, chip);
31 }
32 
33 static void disable_ipr_irq(struct irq_data *data)
34 {
35 	struct ipr_data *p = irq_data_get_irq_chip_data(data);
36 	unsigned long addr = get_ipr_desc(data)->ipr_offsets[p->ipr_idx];
37 	/* Set the priority in IPR to 0 */
38 	__raw_writew(__raw_readw(addr) & (0xffff ^ (0xf << p->shift)), addr);
39 	(void)__raw_readw(addr);	/* Read back to flush write posting */
40 }
41 
42 static void enable_ipr_irq(struct irq_data *data)
43 {
44 	struct ipr_data *p = irq_data_get_irq_chip_data(data);
45 	unsigned long addr = get_ipr_desc(data)->ipr_offsets[p->ipr_idx];
46 	/* Set priority in IPR back to original value */
47 	__raw_writew(__raw_readw(addr) | (p->priority << p->shift), addr);
48 }
49 
50 /*
51  * The shift value is now the number of bits to shift, not the number of
52  * bits/4. This is to make it easier to read the value directly from the
53  * datasheets. The IPR address is calculated using the ipr_offset table.
54  */
55 void register_ipr_controller(struct ipr_desc *desc)
56 {
57 	int i;
58 
59 	desc->chip.irq_mask = disable_ipr_irq;
60 	desc->chip.irq_unmask = enable_ipr_irq;
61 
62 	for (i = 0; i < desc->nr_irqs; i++) {
63 		struct ipr_data *p = desc->ipr_data + i;
64 		int res;
65 
66 		BUG_ON(p->ipr_idx >= desc->nr_offsets);
67 		BUG_ON(!desc->ipr_offsets[p->ipr_idx]);
68 
69 		res = irq_alloc_desc_at(p->irq, numa_node_id());
70 		if (unlikely(res != p->irq && res != -EEXIST)) {
71 			printk(KERN_INFO "can not get irq_desc for %d\n",
72 			       p->irq);
73 			continue;
74 		}
75 
76 		disable_irq_nosync(p->irq);
77 		irq_set_chip_and_handler_name(p->irq, &desc->chip,
78 					      handle_level_irq, "level");
79 		irq_set_chip_data(p->irq, p);
80 		disable_ipr_irq(irq_get_irq_data(p->irq));
81 	}
82 }
83 EXPORT_SYMBOL(register_ipr_controller);
84