1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2019, Jiaxun Yang <jiaxun.yang@flygoat.com>
4 * Loongson-1 platform IRQ support
5 */
6
7 #include <linux/errno.h>
8 #include <linux/init.h>
9 #include <linux/types.h>
10 #include <linux/interrupt.h>
11 #include <linux/ioport.h>
12 #include <linux/irqchip.h>
13 #include <linux/of_address.h>
14 #include <linux/of_irq.h>
15 #include <linux/io.h>
16 #include <linux/irqchip/chained_irq.h>
17
18 #define LS_REG_INTC_STATUS 0x00
19 #define LS_REG_INTC_EN 0x04
20 #define LS_REG_INTC_SET 0x08
21 #define LS_REG_INTC_CLR 0x0c
22 #define LS_REG_INTC_POL 0x10
23 #define LS_REG_INTC_EDGE 0x14
24
25 /**
26 * struct ls1x_intc_priv - private ls1x-intc data.
27 * @domain: IRQ domain.
28 * @intc_base: IO Base of intc registers.
29 */
30
31 struct ls1x_intc_priv {
32 struct irq_domain *domain;
33 void __iomem *intc_base;
34 };
35
36
ls1x_chained_handle_irq(struct irq_desc * desc)37 static void ls1x_chained_handle_irq(struct irq_desc *desc)
38 {
39 struct ls1x_intc_priv *priv = irq_desc_get_handler_data(desc);
40 struct irq_chip *chip = irq_desc_get_chip(desc);
41 u32 pending;
42
43 chained_irq_enter(chip, desc);
44 pending = readl(priv->intc_base + LS_REG_INTC_STATUS) &
45 readl(priv->intc_base + LS_REG_INTC_EN);
46
47 if (!pending)
48 spurious_interrupt();
49
50 while (pending) {
51 int bit = __ffs(pending);
52
53 generic_handle_domain_irq(priv->domain, bit);
54 pending &= ~BIT(bit);
55 }
56
57 chained_irq_exit(chip, desc);
58 }
59
ls_intc_set_bit(struct irq_chip_generic * gc,unsigned int offset,u32 mask,bool set)60 static void ls_intc_set_bit(struct irq_chip_generic *gc,
61 unsigned int offset,
62 u32 mask, bool set)
63 {
64 if (set)
65 writel(readl(gc->reg_base + offset) | mask,
66 gc->reg_base + offset);
67 else
68 writel(readl(gc->reg_base + offset) & ~mask,
69 gc->reg_base + offset);
70 }
71
ls_intc_set_type(struct irq_data * data,unsigned int type)72 static int ls_intc_set_type(struct irq_data *data, unsigned int type)
73 {
74 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
75 u32 mask = data->mask;
76
77 switch (type) {
78 case IRQ_TYPE_LEVEL_HIGH:
79 ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, false);
80 ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, true);
81 break;
82 case IRQ_TYPE_LEVEL_LOW:
83 ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, false);
84 ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, false);
85 break;
86 case IRQ_TYPE_EDGE_RISING:
87 ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, true);
88 ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, true);
89 break;
90 case IRQ_TYPE_EDGE_FALLING:
91 ls_intc_set_bit(gc, LS_REG_INTC_EDGE, mask, true);
92 ls_intc_set_bit(gc, LS_REG_INTC_POL, mask, false);
93 break;
94 default:
95 return -EINVAL;
96 }
97
98 irqd_set_trigger_type(data, type);
99 return irq_setup_alt_chip(data, type);
100 }
101
102
ls1x_intc_of_init(struct device_node * node,struct device_node * parent)103 static int __init ls1x_intc_of_init(struct device_node *node,
104 struct device_node *parent)
105 {
106 struct irq_chip_generic *gc;
107 struct irq_chip_type *ct;
108 struct ls1x_intc_priv *priv;
109 int parent_irq, err = 0;
110
111 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
112 if (!priv)
113 return -ENOMEM;
114
115 priv->intc_base = of_iomap(node, 0);
116 if (!priv->intc_base) {
117 err = -ENODEV;
118 goto out_free_priv;
119 }
120
121 parent_irq = irq_of_parse_and_map(node, 0);
122 if (!parent_irq) {
123 pr_err("ls1x-irq: unable to get parent irq\n");
124 err = -ENODEV;
125 goto out_iounmap;
126 }
127
128 /* Set up an IRQ domain */
129 priv->domain = irq_domain_add_linear(node, 32, &irq_generic_chip_ops,
130 NULL);
131 if (!priv->domain) {
132 pr_err("ls1x-irq: cannot add IRQ domain\n");
133 err = -ENOMEM;
134 goto out_iounmap;
135 }
136
137 err = irq_alloc_domain_generic_chips(priv->domain, 32, 2,
138 node->full_name, handle_level_irq,
139 IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN, 0,
140 IRQ_GC_INIT_MASK_CACHE);
141 if (err) {
142 pr_err("ls1x-irq: unable to register IRQ domain\n");
143 goto out_free_domain;
144 }
145
146 /* Mask all irqs */
147 writel(0x0, priv->intc_base + LS_REG_INTC_EN);
148
149 /* Ack all irqs */
150 writel(0xffffffff, priv->intc_base + LS_REG_INTC_CLR);
151
152 /* Set all irqs to high level triggered */
153 writel(0xffffffff, priv->intc_base + LS_REG_INTC_POL);
154
155 gc = irq_get_domain_generic_chip(priv->domain, 0);
156
157 gc->reg_base = priv->intc_base;
158
159 ct = gc->chip_types;
160 ct[0].type = IRQ_TYPE_LEVEL_MASK;
161 ct[0].regs.mask = LS_REG_INTC_EN;
162 ct[0].regs.ack = LS_REG_INTC_CLR;
163 ct[0].chip.irq_unmask = irq_gc_mask_set_bit;
164 ct[0].chip.irq_mask = irq_gc_mask_clr_bit;
165 ct[0].chip.irq_ack = irq_gc_ack_set_bit;
166 ct[0].chip.irq_set_type = ls_intc_set_type;
167 ct[0].handler = handle_level_irq;
168
169 ct[1].type = IRQ_TYPE_EDGE_BOTH;
170 ct[1].regs.mask = LS_REG_INTC_EN;
171 ct[1].regs.ack = LS_REG_INTC_CLR;
172 ct[1].chip.irq_unmask = irq_gc_mask_set_bit;
173 ct[1].chip.irq_mask = irq_gc_mask_clr_bit;
174 ct[1].chip.irq_ack = irq_gc_ack_set_bit;
175 ct[1].chip.irq_set_type = ls_intc_set_type;
176 ct[1].handler = handle_edge_irq;
177
178 irq_set_chained_handler_and_data(parent_irq,
179 ls1x_chained_handle_irq, priv);
180
181 return 0;
182
183 out_free_domain:
184 irq_domain_remove(priv->domain);
185 out_iounmap:
186 iounmap(priv->intc_base);
187 out_free_priv:
188 kfree(priv);
189
190 return err;
191 }
192
193 IRQCHIP_DECLARE(ls1x_intc, "loongson,ls1x-intc", ls1x_intc_of_init);
194