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 	irq_gc_lock(gc);
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 	irq_gc_unlock(gc);
58 }
59 
60 static void __init ck_set_gc(struct device_node *node, void __iomem *reg_base,
61 			     u32 mask_reg, u32 irq_base)
62 {
63 	struct irq_chip_generic *gc;
64 
65 	gc = irq_get_domain_generic_chip(root_domain, irq_base);
66 	gc->reg_base = reg_base;
67 	gc->chip_types[0].regs.mask = mask_reg;
68 	gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
69 	gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
70 
71 	if (of_find_property(node, "csky,support-pulse-signal", NULL))
72 		gc->chip_types[0].chip.irq_unmask = irq_ck_mask_set_bit;
73 }
74 
75 static inline u32 build_channel_val(u32 idx, u32 magic)
76 {
77 	u32 res;
78 
79 	/*
80 	 * Set the same index for each channel
81 	 */
82 	res = idx | (idx << 8) | (idx << 16) | (idx << 24);
83 
84 	/*
85 	 * Set the channel magic number in descending order.
86 	 * The magic is 0x00010203 for ck-intc
87 	 * The magic is 0x03020100 for gx6605s-intc
88 	 */
89 	return res | magic;
90 }
91 
92 static inline void setup_irq_channel(u32 magic, void __iomem *reg_addr)
93 {
94 	u32 i;
95 
96 	/* Setup 64 channel slots */
97 	for (i = 0; i < INTC_IRQS; i += 4)
98 		writel(build_channel_val(i, magic), reg_addr + i);
99 }
100 
101 static int __init
102 ck_intc_init_comm(struct device_node *node, struct device_node *parent)
103 {
104 	int ret;
105 
106 	if (parent) {
107 		pr_err("C-SKY Intc not a root irq controller\n");
108 		return -EINVAL;
109 	}
110 
111 	reg_base = of_iomap(node, 0);
112 	if (!reg_base) {
113 		pr_err("C-SKY Intc unable to map: %p.\n", node);
114 		return -EINVAL;
115 	}
116 
117 	root_domain = irq_domain_add_linear(node, nr_irq,
118 					    &irq_generic_chip_ops, NULL);
119 	if (!root_domain) {
120 		pr_err("C-SKY Intc irq_domain_add failed.\n");
121 		return -ENOMEM;
122 	}
123 
124 	ret = irq_alloc_domain_generic_chips(root_domain, 32, 1,
125 			"csky_intc", handle_level_irq,
126 			IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN, 0, 0);
127 	if (ret) {
128 		pr_err("C-SKY Intc irq_alloc_gc failed.\n");
129 		return -ENOMEM;
130 	}
131 
132 	return 0;
133 }
134 
135 static inline bool handle_irq_perbit(struct pt_regs *regs, u32 hwirq,
136 				     u32 irq_base)
137 {
138 	if (hwirq == 0)
139 		return false;
140 
141 	generic_handle_domain_irq(root_domain, irq_base + __fls(hwirq));
142 
143 	return true;
144 }
145 
146 /* gx6605s 64 irqs interrupt controller */
147 static void gx_irq_handler(struct pt_regs *regs)
148 {
149 	bool ret;
150 
151 retry:
152 	ret = handle_irq_perbit(regs,
153 			readl(reg_base + GX_INTC_PEN63_32), 32);
154 	if (ret)
155 		goto retry;
156 
157 	ret = handle_irq_perbit(regs,
158 			readl(reg_base + GX_INTC_PEN31_00), 0);
159 	if (ret)
160 		goto retry;
161 }
162 
163 static int __init
164 gx_intc_init(struct device_node *node, struct device_node *parent)
165 {
166 	int ret;
167 
168 	ret = ck_intc_init_comm(node, parent);
169 	if (ret)
170 		return ret;
171 
172 	/*
173 	 * Initial enable reg to disable all interrupts
174 	 */
175 	writel(0x0, reg_base + GX_INTC_NEN31_00);
176 	writel(0x0, reg_base + GX_INTC_NEN63_32);
177 
178 	/*
179 	 * Initial mask reg with all unmasked, because we only use enable reg
180 	 */
181 	writel(0x0, reg_base + GX_INTC_NMASK31_00);
182 	writel(0x0, reg_base + GX_INTC_NMASK63_32);
183 
184 	setup_irq_channel(0x03020100, reg_base + GX_INTC_SOURCE);
185 
186 	ck_set_gc(node, reg_base, GX_INTC_NEN31_00, 0);
187 	ck_set_gc(node, reg_base, GX_INTC_NEN63_32, 32);
188 
189 	set_handle_irq(gx_irq_handler);
190 
191 	return 0;
192 }
193 IRQCHIP_DECLARE(csky_gx6605s_intc, "csky,gx6605s-intc", gx_intc_init);
194 
195 /*
196  * C-SKY simple 64 irqs interrupt controller, dual-together could support 128
197  * irqs.
198  */
199 static void ck_irq_handler(struct pt_regs *regs)
200 {
201 	bool ret;
202 	void __iomem *reg_pen_lo = reg_base + CK_INTC_PEN31_00;
203 	void __iomem *reg_pen_hi = reg_base + CK_INTC_PEN63_32;
204 
205 retry:
206 	/* handle 0 - 63 irqs */
207 	ret = handle_irq_perbit(regs, readl(reg_pen_hi), 32);
208 	if (ret)
209 		goto retry;
210 
211 	ret = handle_irq_perbit(regs, readl(reg_pen_lo), 0);
212 	if (ret)
213 		goto retry;
214 
215 	if (nr_irq == INTC_IRQS)
216 		return;
217 
218 	/* handle 64 - 127 irqs */
219 	ret = handle_irq_perbit(regs,
220 			readl(reg_pen_hi + CK_INTC_DUAL_BASE), 96);
221 	if (ret)
222 		goto retry;
223 
224 	ret = handle_irq_perbit(regs,
225 			readl(reg_pen_lo + CK_INTC_DUAL_BASE), 64);
226 	if (ret)
227 		goto retry;
228 }
229 
230 static int __init
231 ck_intc_init(struct device_node *node, struct device_node *parent)
232 {
233 	int ret;
234 
235 	ret = ck_intc_init_comm(node, parent);
236 	if (ret)
237 		return ret;
238 
239 	/* Initial enable reg to disable all interrupts */
240 	writel(0, reg_base + CK_INTC_NEN31_00);
241 	writel(0, reg_base + CK_INTC_NEN63_32);
242 
243 	/* Enable irq intc */
244 	writel(BIT(31), reg_base + CK_INTC_ICR);
245 
246 	ck_set_gc(node, reg_base, CK_INTC_NEN31_00, 0);
247 	ck_set_gc(node, reg_base, CK_INTC_NEN63_32, 32);
248 
249 	setup_irq_channel(0x00010203, reg_base + CK_INTC_SOURCE);
250 
251 	set_handle_irq(ck_irq_handler);
252 
253 	return 0;
254 }
255 IRQCHIP_DECLARE(ck_intc, "csky,apb-intc", ck_intc_init);
256 
257 static int __init
258 ck_dual_intc_init(struct device_node *node, struct device_node *parent)
259 {
260 	int ret;
261 
262 	/* dual-apb-intc up to 128 irq sources*/
263 	nr_irq = INTC_IRQS * 2;
264 
265 	ret = ck_intc_init(node, parent);
266 	if (ret)
267 		return ret;
268 
269 	/* Initial enable reg to disable all interrupts */
270 	writel(0, reg_base + CK_INTC_NEN31_00 + CK_INTC_DUAL_BASE);
271 	writel(0, reg_base + CK_INTC_NEN63_32 + CK_INTC_DUAL_BASE);
272 
273 	ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN31_00, 64);
274 	ck_set_gc(node, reg_base + CK_INTC_DUAL_BASE, CK_INTC_NEN63_32, 96);
275 
276 	setup_irq_channel(0x00010203,
277 			  reg_base + CK_INTC_SOURCE + CK_INTC_DUAL_BASE);
278 
279 	return 0;
280 }
281 IRQCHIP_DECLARE(ck_dual_intc, "csky,dual-apb-intc", ck_dual_intc_init);
282