1 /*
2  * arch/arm/plat-spear/shirq.c
3  *
4  * SPEAr platform shared irq layer source file
5  *
6  * Copyright (C) 2009 ST Microelectronics
7  * Viresh Kumar<viresh.kumar@st.com>
8  *
9  * This file is licensed under the terms of the GNU General Public
10  * License version 2. This program is licensed "as is" without any
11  * warranty of any kind, whether express or implied.
12  */
13 
14 #include <linux/err.h>
15 #include <linux/io.h>
16 #include <linux/irq.h>
17 #include <linux/spinlock.h>
18 #include <plat/shirq.h>
19 
20 struct spear_shirq *shirq;
21 static DEFINE_SPINLOCK(lock);
22 
shirq_irq_mask(struct irq_data * d)23 static void shirq_irq_mask(struct irq_data *d)
24 {
25 	struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
26 	u32 val, id = d->irq - shirq->dev_config[0].virq;
27 	unsigned long flags;
28 
29 	if ((shirq->regs.enb_reg == -1) || shirq->dev_config[id].enb_mask == -1)
30 		return;
31 
32 	spin_lock_irqsave(&lock, flags);
33 	val = readl(shirq->regs.base + shirq->regs.enb_reg);
34 	if (shirq->regs.reset_to_enb)
35 		val |= shirq->dev_config[id].enb_mask;
36 	else
37 		val &= ~(shirq->dev_config[id].enb_mask);
38 	writel(val, shirq->regs.base + shirq->regs.enb_reg);
39 	spin_unlock_irqrestore(&lock, flags);
40 }
41 
shirq_irq_unmask(struct irq_data * d)42 static void shirq_irq_unmask(struct irq_data *d)
43 {
44 	struct spear_shirq *shirq = irq_data_get_irq_chip_data(d);
45 	u32 val, id = d->irq - shirq->dev_config[0].virq;
46 	unsigned long flags;
47 
48 	if ((shirq->regs.enb_reg == -1) || shirq->dev_config[id].enb_mask == -1)
49 		return;
50 
51 	spin_lock_irqsave(&lock, flags);
52 	val = readl(shirq->regs.base + shirq->regs.enb_reg);
53 	if (shirq->regs.reset_to_enb)
54 		val &= ~(shirq->dev_config[id].enb_mask);
55 	else
56 		val |= shirq->dev_config[id].enb_mask;
57 	writel(val, shirq->regs.base + shirq->regs.enb_reg);
58 	spin_unlock_irqrestore(&lock, flags);
59 }
60 
61 static struct irq_chip shirq_chip = {
62 	.name		= "spear_shirq",
63 	.irq_ack	= shirq_irq_mask,
64 	.irq_mask	= shirq_irq_mask,
65 	.irq_unmask	= shirq_irq_unmask,
66 };
67 
shirq_handler(unsigned irq,struct irq_desc * desc)68 static void shirq_handler(unsigned irq, struct irq_desc *desc)
69 {
70 	u32 i, val, mask;
71 	struct spear_shirq *shirq = irq_get_handler_data(irq);
72 
73 	desc->irq_data.chip->irq_ack(&desc->irq_data);
74 	while ((val = readl(shirq->regs.base + shirq->regs.status_reg) &
75 				shirq->regs.status_reg_mask)) {
76 		for (i = 0; (i < shirq->dev_count) && val; i++) {
77 			if (!(shirq->dev_config[i].status_mask & val))
78 				continue;
79 
80 			generic_handle_irq(shirq->dev_config[i].virq);
81 
82 			/* clear interrupt */
83 			val &= ~shirq->dev_config[i].status_mask;
84 			if ((shirq->regs.clear_reg == -1) ||
85 					shirq->dev_config[i].clear_mask == -1)
86 				continue;
87 			mask = readl(shirq->regs.base + shirq->regs.clear_reg);
88 			if (shirq->regs.reset_to_clear)
89 				mask &= ~shirq->dev_config[i].clear_mask;
90 			else
91 				mask |= shirq->dev_config[i].clear_mask;
92 			writel(mask, shirq->regs.base + shirq->regs.clear_reg);
93 		}
94 	}
95 	desc->irq_data.chip->irq_unmask(&desc->irq_data);
96 }
97 
spear_shirq_register(struct spear_shirq * shirq)98 int spear_shirq_register(struct spear_shirq *shirq)
99 {
100 	int i;
101 
102 	if (!shirq || !shirq->dev_config || !shirq->regs.base)
103 		return -EFAULT;
104 
105 	if (!shirq->dev_count)
106 		return -EINVAL;
107 
108 	irq_set_chained_handler(shirq->irq, shirq_handler);
109 	for (i = 0; i < shirq->dev_count; i++) {
110 		irq_set_chip_and_handler(shirq->dev_config[i].virq,
111 					 &shirq_chip, handle_simple_irq);
112 		set_irq_flags(shirq->dev_config[i].virq, IRQF_VALID);
113 		irq_set_chip_data(shirq->dev_config[i].virq, shirq);
114 	}
115 
116 	irq_set_handler_data(shirq->irq, shirq);
117 	return 0;
118 }
119