1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3 
4 #include <linux/kernel.h>
5 #include <linux/init.h>
6 #include <linux/of.h>
7 #include <linux/of_address.h>
8 #include <linux/module.h>
9 #include <linux/irqdomain.h>
10 #include <linux/irqchip.h>
11 #include <linux/irq.h>
12 #include <linux/interrupt.h>
13 #include <linux/io.h>
14 #include <asm/irq.h>
15 
16 #define INTC_IRQS		64
17 
18 #define CK_INTC_ICR		0x00
19 #define CK_INTC_PEN31_00	0x14
20 #define CK_INTC_PEN63_32	0x2c
21 #define CK_INTC_NEN31_00	0x10
22 #define CK_INTC_NEN63_32	0x28
23 #define CK_INTC_SOURCE		0x40
24 #define CK_INTC_DUAL_BASE	0x100
25 
26 #define GX_INTC_PEN31_00	0x00
27 #define GX_INTC_PEN63_32	0x04
28 #define GX_INTC_NEN31_00	0x40
29 #define GX_INTC_NEN63_32	0x44
30 #define GX_INTC_NMASK31_00	0x50
31 #define GX_INTC_NMASK63_32	0x54
32 #define GX_INTC_SOURCE		0x60
33 
34 static void __iomem *reg_base;
35 static struct irq_domain *root_domain;
36 
37 static int nr_irq = INTC_IRQS;
38 
39 /*
40  * When controller support pulse signal, the PEN_reg will hold on signal
41  * without software trigger.
42  *
43  * So, to support pulse signal we need to clear IFR_reg and the address of
44  * IFR_offset is NEN_offset - 8.
45  */
46 static void irq_ck_mask_set_bit(struct irq_data *d)
47 {
48 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
49 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
50 	unsigned long ifr = ct->regs.mask - 8;
51 	u32 mask = d->mask;
52 
53 	guard(raw_spinlock)(&gc->lock);
54 	*ct->mask_cache |= mask;
55 	irq_reg_writel(gc, *ct->mask_cache, ct->regs.mask);
56 	irq_reg_writel(gc, irq_reg_readl(gc, ifr) & ~mask, ifr);
57 }
58 
59 static void __init ck_set_gc(struct device_node *node, void __iomem *reg_base,
60 			     u32 mask_reg, u32 irq_base)
61 {
62 	struct irq_chip_generic *gc;
63 
64 	gc = irq_get_domain_generic_chip(root_domain, irq_base);
65 	gc->reg_base = reg_base;
66 	gc->chip_types[0].regs.mask = mask_reg;
67 	gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
68 	gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
69 
70 	if (of_property_read_bool(node, "csky,support-pulse-signal"))
71 		gc->chip_types[0].chip.irq_unmask = irq_ck_mask_set_bit;
72 }
73 
74 static inline u32 build_channel_val(u32 idx, u32 magic)
75 {
76 	u32 res;
77 
78 	/*
79 	 * Set the same index for each channel
80 	 */
81 	res = idx | (idx << 8) | (idx << 16) | (idx << 24);
82 
83 	/*
84 	 * Set the channel magic number in descending order.
85 	 * The magic is 0x00010203 for ck-intc
86 	 * The magic is 0x03020100 for gx6605s-intc
87 	 */
88 	return res | magic;
89 }
90 
91 static inline void setup_irq_channel(u32 magic, void __iomem *reg_addr)
92 {
93 	u32 i;
94 
95 	/* Setup 64 channel slots */
96 	for (i = 0; i < INTC_IRQS; i += 4)
97 		writel(build_channel_val(i, magic), reg_addr + i);
98 }
99 
100 static int __init
101 ck_intc_init_comm(struct device_node *node, struct device_node *parent)
102 {
103 	int ret;
104 
105 	if (parent) {
106 		pr_err("C-SKY Intc not a root irq controller\n");
107 		return -EINVAL;
108 	}
109 
110 	reg_base = of_iomap(node, 0);
111 	if (!reg_base) {
112 		pr_err("C-SKY Intc unable to map: %p.\n", node);
113 		return -EINVAL;
114 	}
115 
116 	root_domain = irq_domain_create_linear(of_fwnode_handle(node), nr_irq,
117 					    &irq_generic_chip_ops, NULL);
118 	if (!root_domain) {
119 		pr_err("C-SKY Intc irq_domain_add failed.\n");
120 		return -ENOMEM;
121 	}
122 
123 	ret = irq_alloc_domain_generic_chips(root_domain, 32, 1,
124 			"csky_intc", handle_level_irq,
125 			IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN, 0, 0);
126 	if (ret) {
127 		pr_err("C-SKY Intc irq_alloc_gc failed.\n");
128 		return -ENOMEM;
129 	}
130 
131 	return 0;
132 }
133 
134 static inline bool handle_irq_perbit(struct pt_regs *regs, u32 hwirq,
135 				     u32 irq_base)
136 {
137 	if (hwirq == 0)
138 		return false;
139 
140 	generic_handle_domain_irq(root_domain, irq_base + __fls(hwirq));
141 
142 	return true;
143 }
144 
145 /* gx6605s 64 irqs interrupt controller */
146 static void gx_irq_handler(struct pt_regs *regs)
147 {
148 	bool ret;
149 
150 retry:
151 	ret = handle_irq_perbit(regs,
152 			readl(reg_base + GX_INTC_PEN63_32), 32);
153 	if (ret)
154 		goto retry;
155 
156 	ret = handle_irq_perbit(regs,
157 			readl(reg_base + GX_INTC_PEN31_00), 0);
158 	if (ret)
159 		goto retry;
160 }
161 
162 static int __init
163 gx_intc_init(struct device_node *node, struct device_node *parent)
164 {
165 	int ret;
166 
167 	ret = ck_intc_init_comm(node, parent);
168 	if (ret)
169 		return ret;
170 
171 	/*
172 	 * Initial enable reg to disable all interrupts
173 	 */
174 	writel(0x0, reg_base + GX_INTC_NEN31_00);
175 	writel(0x0, reg_base + GX_INTC_NEN63_32);
176 
177 	/*
178 	 * Initial mask reg with all unmasked, because we only use enable reg
179 	 */
180 	writel(0x0, reg_base + GX_INTC_NMASK31_00);
181 	writel(0x0, reg_base + GX_INTC_NMASK63_32);
182 
183 	setup_irq_channel(0x03020100, reg_base + GX_INTC_SOURCE);
184 
185 	ck_set_gc(node, reg_base, GX_INTC_NEN31_00, 0);
186 	ck_set_gc(node, reg_base, GX_INTC_NEN63_32, 32);
187 
188 	set_handle_irq(gx_irq_handler);
189 
190 	return 0;
191 }
192 IRQCHIP_DECLARE(csky_gx6605s_intc, "csky,gx6605s-intc", gx_intc_init);
193 
194 /*
195  * C-SKY simple 64 irqs interrupt controller, dual-together could support 128
196  * irqs.
197  */
198 static void ck_irq_handler(struct pt_regs *regs)
199 {
200 	bool ret;
201 	void __iomem *reg_pen_lo = reg_base + CK_INTC_PEN31_00;
202 	void __iomem *reg_pen_hi = reg_base + CK_INTC_PEN63_32;
203 
204 retry:
205 	/* handle 0 - 63 irqs */
206 	ret = handle_irq_perbit(regs, readl(reg_pen_hi), 32);
207 	if (ret)
208 		goto retry;
209 
210 	ret = handle_irq_perbit(regs, readl(reg_pen_lo), 0);
211 	if (ret)
212 		goto retry;
213 
214 	if (nr_irq == INTC_IRQS)
215 		return;
216 
217 	/* handle 64 - 127 irqs */
218 	ret = handle_irq_perbit(regs,
219 			readl(reg_pen_hi + CK_INTC_DUAL_BASE), 96);
220 	if (ret)
221 		goto retry;
222 
223 	ret = handle_irq_perbit(regs,
224 			readl(reg_pen_lo + CK_INTC_DUAL_BASE), 64);
225 	if (ret)
226 		goto retry;
227 }
228 
229 static int __init
230 ck_intc_init(struct device_node *node, struct device_node *parent)
231 {
232 	int ret;
233 
234 	ret = ck_intc_init_comm(node, parent);
235 	if (ret)
236 		return ret;
237 
238 	/* Initial enable reg to disable all interrupts */
239 	writel(0, reg_base + CK_INTC_NEN31_00);
240 	writel(0, reg_base + CK_INTC_NEN63_32);
241 
242 	/* Enable irq intc */
243 	writel(BIT(31), reg_base + CK_INTC_ICR);
244 
245 	ck_set_gc(node, reg_base, CK_INTC_NEN31_00, 0);
246 	ck_set_gc(node, reg_base, CK_INTC_NEN63_32, 32);
247 
248 	setup_irq_channel(0x00010203, reg_base + CK_INTC_SOURCE);
249 
250 	set_handle_irq(ck_irq_handler);
251 
252 	return 0;
253 }
254 IRQCHIP_DECLARE(ck_intc, "csky,apb-intc", ck_intc_init);
255 
256 static int __init
257 ck_dual_intc_init(struct device_node *node, struct device_node *parent)
258 {
259 	int ret;
260 
261 	/* dual-apb-intc up to 128 irq sources*/
262 	nr_irq = INTC_IRQS * 2;
263 
264 	ret = ck_intc_init(node, parent);
265 	if (ret)
266 		return ret;
267 
268 	/* Initial enable reg to disable all interrupts */
269 	writel(0, reg_base + CK_INTC_NEN31_00 + CK_INTC_DUAL_BASE);
270 	writel(0, reg_base + CK_INTC_NEN63_32 + CK_INTC_DUAL_BASE);
271 
272 	ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN31_00, 64);
273 	ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN63_32, 96);
274 
275 	setup_irq_channel(0x00010203,
276 			  reg_base + CK_INTC_SOURCE + CK_INTC_DUAL_BASE);
277 
278 	return 0;
279 }
280 IRQCHIP_DECLARE(ck_dual_intc, "csky,dual-apb-intc", ck_dual_intc_init);
281