1 /*
2  *  Atheros AR71xx/AR724x/AR913x MISC interrupt controller
3  *
4  *  Copyright (C) 2015 Alban Bedel <albeu@free.fr>
5  *  Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com>
6  *  Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
7  *  Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
8  *
9  *  Parts of this file are based on Atheros' 2.6.15/2.6.31 BSP
10  *
11  *  This program is free software; you can redistribute it and/or modify it
12  *  under the terms of the GNU General Public License version 2 as published
13  *  by the Free Software Foundation.
14  */
15 
16 #include <linux/irqchip.h>
17 #include <linux/irqchip/chained_irq.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 
21 #define AR71XX_RESET_REG_MISC_INT_STATUS	0
22 #define AR71XX_RESET_REG_MISC_INT_ENABLE	4
23 
24 #define ATH79_MISC_IRQ_COUNT			32
25 #define ATH79_MISC_PERF_IRQ			5
26 
27 static int ath79_perfcount_irq;
28 
29 int get_c0_perfcount_int(void)
30 {
31 	return ath79_perfcount_irq;
32 }
33 EXPORT_SYMBOL_GPL(get_c0_perfcount_int);
34 
35 static void ath79_misc_irq_handler(struct irq_desc *desc)
36 {
37 	struct irq_domain *domain = irq_desc_get_handler_data(desc);
38 	struct irq_chip *chip = irq_desc_get_chip(desc);
39 	void __iomem *base = domain->host_data;
40 	u32 pending;
41 
42 	chained_irq_enter(chip, desc);
43 
44 	pending = __raw_readl(base + AR71XX_RESET_REG_MISC_INT_STATUS) &
45 		  __raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
46 
47 	if (!pending) {
48 		spurious_interrupt();
49 		chained_irq_exit(chip, desc);
50 		return;
51 	}
52 
53 	while (pending) {
54 		int bit = __ffs(pending);
55 
56 		generic_handle_irq(irq_linear_revmap(domain, bit));
57 		pending &= ~BIT(bit);
58 	}
59 
60 	chained_irq_exit(chip, desc);
61 }
62 
63 static void ar71xx_misc_irq_unmask(struct irq_data *d)
64 {
65 	void __iomem *base = irq_data_get_irq_chip_data(d);
66 	unsigned int irq = d->hwirq;
67 	u32 t;
68 
69 	t = __raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
70 	__raw_writel(t | BIT(irq), base + AR71XX_RESET_REG_MISC_INT_ENABLE);
71 
72 	/* flush write */
73 	__raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
74 }
75 
76 static void ar71xx_misc_irq_mask(struct irq_data *d)
77 {
78 	void __iomem *base = irq_data_get_irq_chip_data(d);
79 	unsigned int irq = d->hwirq;
80 	u32 t;
81 
82 	t = __raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
83 	__raw_writel(t & ~BIT(irq), base + AR71XX_RESET_REG_MISC_INT_ENABLE);
84 
85 	/* flush write */
86 	__raw_readl(base + AR71XX_RESET_REG_MISC_INT_ENABLE);
87 }
88 
89 static void ar724x_misc_irq_ack(struct irq_data *d)
90 {
91 	void __iomem *base = irq_data_get_irq_chip_data(d);
92 	unsigned int irq = d->hwirq;
93 	u32 t;
94 
95 	t = __raw_readl(base + AR71XX_RESET_REG_MISC_INT_STATUS);
96 	__raw_writel(t & ~BIT(irq), base + AR71XX_RESET_REG_MISC_INT_STATUS);
97 
98 	/* flush write */
99 	__raw_readl(base + AR71XX_RESET_REG_MISC_INT_STATUS);
100 }
101 
102 static struct irq_chip ath79_misc_irq_chip = {
103 	.name		= "MISC",
104 	.irq_unmask	= ar71xx_misc_irq_unmask,
105 	.irq_mask	= ar71xx_misc_irq_mask,
106 };
107 
108 static int misc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
109 {
110 	irq_set_chip_and_handler(irq, &ath79_misc_irq_chip, handle_level_irq);
111 	irq_set_chip_data(irq, d->host_data);
112 	return 0;
113 }
114 
115 static const struct irq_domain_ops misc_irq_domain_ops = {
116 	.xlate = irq_domain_xlate_onecell,
117 	.map = misc_map,
118 };
119 
120 static void __init ath79_misc_intc_domain_init(
121 	struct irq_domain *domain, int irq)
122 {
123 	void __iomem *base = domain->host_data;
124 
125 	ath79_perfcount_irq = irq_create_mapping(domain, ATH79_MISC_PERF_IRQ);
126 
127 	/* Disable and clear all interrupts */
128 	__raw_writel(0, base + AR71XX_RESET_REG_MISC_INT_ENABLE);
129 	__raw_writel(0, base + AR71XX_RESET_REG_MISC_INT_STATUS);
130 
131 	irq_set_chained_handler_and_data(irq, ath79_misc_irq_handler, domain);
132 }
133 
134 static int __init ath79_misc_intc_of_init(
135 	struct device_node *node, struct device_node *parent)
136 {
137 	struct irq_domain *domain;
138 	void __iomem *base;
139 	int irq;
140 
141 	irq = irq_of_parse_and_map(node, 0);
142 	if (!irq) {
143 		pr_err("Failed to get MISC IRQ\n");
144 		return -EINVAL;
145 	}
146 
147 	base = of_iomap(node, 0);
148 	if (!base) {
149 		pr_err("Failed to get MISC IRQ registers\n");
150 		return -ENOMEM;
151 	}
152 
153 	domain = irq_domain_add_linear(node, ATH79_MISC_IRQ_COUNT,
154 				&misc_irq_domain_ops, base);
155 	if (!domain) {
156 		pr_err("Failed to add MISC irqdomain\n");
157 		return -EINVAL;
158 	}
159 
160 	ath79_misc_intc_domain_init(domain, irq);
161 	return 0;
162 }
163 
164 static int __init ar7100_misc_intc_of_init(
165 	struct device_node *node, struct device_node *parent)
166 {
167 	ath79_misc_irq_chip.irq_mask_ack = ar71xx_misc_irq_mask;
168 	return ath79_misc_intc_of_init(node, parent);
169 }
170 
171 IRQCHIP_DECLARE(ar7100_misc_intc, "qca,ar7100-misc-intc",
172 		ar7100_misc_intc_of_init);
173 
174 static int __init ar7240_misc_intc_of_init(
175 	struct device_node *node, struct device_node *parent)
176 {
177 	ath79_misc_irq_chip.irq_ack = ar724x_misc_irq_ack;
178 	return ath79_misc_intc_of_init(node, parent);
179 }
180 
181 IRQCHIP_DECLARE(ar7240_misc_intc, "qca,ar7240-misc-intc",
182 		ar7240_misc_intc_of_init);
183 
184 void __init ath79_misc_irq_init(void __iomem *regs, int irq,
185 				int irq_base, bool is_ar71xx)
186 {
187 	struct irq_domain *domain;
188 
189 	if (is_ar71xx)
190 		ath79_misc_irq_chip.irq_mask_ack = ar71xx_misc_irq_mask;
191 	else
192 		ath79_misc_irq_chip.irq_ack = ar724x_misc_irq_ack;
193 
194 	domain = irq_domain_add_legacy(NULL, ATH79_MISC_IRQ_COUNT,
195 			irq_base, 0, &misc_irq_domain_ops, regs);
196 	if (!domain)
197 		panic("Failed to create MISC irqdomain");
198 
199 	ath79_misc_intc_domain_init(domain, irq);
200 }
201