xref: /openbmc/linux/drivers/irqchip/irq-lpc32xx.c (revision 35267cea)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2015-2016 Vladimir Zapolskiy <vz@mleia.com>
4  */
5 
6 #define pr_fmt(fmt) "%s: " fmt, __func__
7 
8 #include <linux/io.h>
9 #include <linux/irqchip.h>
10 #include <linux/irqchip/chained_irq.h>
11 #include <linux/of_address.h>
12 #include <linux/of_irq.h>
13 #include <linux/of_platform.h>
14 #include <linux/slab.h>
15 #include <asm/exception.h>
16 
17 #define LPC32XX_INTC_MASK		0x00
18 #define LPC32XX_INTC_RAW		0x04
19 #define LPC32XX_INTC_STAT		0x08
20 #define LPC32XX_INTC_POL		0x0C
21 #define LPC32XX_INTC_TYPE		0x10
22 #define LPC32XX_INTC_FIQ		0x14
23 
24 #define NR_LPC32XX_IC_IRQS		32
25 
26 struct lpc32xx_irq_chip {
27 	void __iomem *base;
28 	struct irq_domain *domain;
29 	struct irq_chip chip;
30 };
31 
32 static struct lpc32xx_irq_chip *lpc32xx_mic_irqc;
33 
34 static inline u32 lpc32xx_ic_read(struct lpc32xx_irq_chip *ic, u32 reg)
35 {
36 	return readl_relaxed(ic->base + reg);
37 }
38 
39 static inline void lpc32xx_ic_write(struct lpc32xx_irq_chip *ic,
40 				    u32 reg, u32 val)
41 {
42 	writel_relaxed(val, ic->base + reg);
43 }
44 
45 static void lpc32xx_irq_mask(struct irq_data *d)
46 {
47 	struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
48 	u32 val, mask = BIT(d->hwirq);
49 
50 	val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) & ~mask;
51 	lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);
52 }
53 
54 static void lpc32xx_irq_unmask(struct irq_data *d)
55 {
56 	struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
57 	u32 val, mask = BIT(d->hwirq);
58 
59 	val = lpc32xx_ic_read(ic, LPC32XX_INTC_MASK) | mask;
60 	lpc32xx_ic_write(ic, LPC32XX_INTC_MASK, val);
61 }
62 
63 static void lpc32xx_irq_ack(struct irq_data *d)
64 {
65 	struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
66 	u32 mask = BIT(d->hwirq);
67 
68 	lpc32xx_ic_write(ic, LPC32XX_INTC_RAW, mask);
69 }
70 
71 static int lpc32xx_irq_set_type(struct irq_data *d, unsigned int type)
72 {
73 	struct lpc32xx_irq_chip *ic = irq_data_get_irq_chip_data(d);
74 	u32 val, mask = BIT(d->hwirq);
75 	bool high, edge;
76 
77 	switch (type) {
78 	case IRQ_TYPE_EDGE_RISING:
79 		edge = true;
80 		high = true;
81 		break;
82 	case IRQ_TYPE_EDGE_FALLING:
83 		edge = true;
84 		high = false;
85 		break;
86 	case IRQ_TYPE_LEVEL_HIGH:
87 		edge = false;
88 		high = true;
89 		break;
90 	case IRQ_TYPE_LEVEL_LOW:
91 		edge = false;
92 		high = false;
93 		break;
94 	default:
95 		pr_info("unsupported irq type %d\n", type);
96 		return -EINVAL;
97 	}
98 
99 	irqd_set_trigger_type(d, type);
100 
101 	val = lpc32xx_ic_read(ic, LPC32XX_INTC_POL);
102 	if (high)
103 		val |= mask;
104 	else
105 		val &= ~mask;
106 	lpc32xx_ic_write(ic, LPC32XX_INTC_POL, val);
107 
108 	val = lpc32xx_ic_read(ic, LPC32XX_INTC_TYPE);
109 	if (edge) {
110 		val |= mask;
111 		irq_set_handler_locked(d, handle_edge_irq);
112 	} else {
113 		val &= ~mask;
114 		irq_set_handler_locked(d, handle_level_irq);
115 	}
116 	lpc32xx_ic_write(ic, LPC32XX_INTC_TYPE, val);
117 
118 	return 0;
119 }
120 
121 static void __exception_irq_entry lpc32xx_handle_irq(struct pt_regs *regs)
122 {
123 	struct lpc32xx_irq_chip *ic = lpc32xx_mic_irqc;
124 	u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;
125 
126 	while (hwirq) {
127 		irq = __ffs(hwirq);
128 		hwirq &= ~BIT(irq);
129 		handle_domain_irq(lpc32xx_mic_irqc->domain, irq, regs);
130 	}
131 }
132 
133 static void lpc32xx_sic_handler(struct irq_desc *desc)
134 {
135 	struct lpc32xx_irq_chip *ic = irq_desc_get_handler_data(desc);
136 	struct irq_chip *chip = irq_desc_get_chip(desc);
137 	u32 hwirq = lpc32xx_ic_read(ic, LPC32XX_INTC_STAT), irq;
138 
139 	chained_irq_enter(chip, desc);
140 
141 	while (hwirq) {
142 		irq = __ffs(hwirq);
143 		hwirq &= ~BIT(irq);
144 		generic_handle_domain_irq(ic->domain, irq);
145 	}
146 
147 	chained_irq_exit(chip, desc);
148 }
149 
150 static int lpc32xx_irq_domain_map(struct irq_domain *id, unsigned int virq,
151 				  irq_hw_number_t hw)
152 {
153 	struct lpc32xx_irq_chip *ic = id->host_data;
154 
155 	irq_set_chip_data(virq, ic);
156 	irq_set_chip_and_handler(virq, &ic->chip, handle_level_irq);
157 	irq_set_status_flags(virq, IRQ_LEVEL);
158 	irq_set_noprobe(virq);
159 
160 	return 0;
161 }
162 
163 static void lpc32xx_irq_domain_unmap(struct irq_domain *id, unsigned int virq)
164 {
165 	irq_set_chip_and_handler(virq, NULL, NULL);
166 }
167 
168 static const struct irq_domain_ops lpc32xx_irq_domain_ops = {
169 	.map    = lpc32xx_irq_domain_map,
170 	.unmap	= lpc32xx_irq_domain_unmap,
171 	.xlate  = irq_domain_xlate_twocell,
172 };
173 
174 static int __init lpc32xx_of_ic_init(struct device_node *node,
175 				     struct device_node *parent)
176 {
177 	struct lpc32xx_irq_chip *irqc;
178 	bool is_mic = of_device_is_compatible(node, "nxp,lpc3220-mic");
179 	const __be32 *reg = of_get_property(node, "reg", NULL);
180 	u32 parent_irq, i, addr = reg ? be32_to_cpu(*reg) : 0;
181 
182 	irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
183 	if (!irqc)
184 		return -ENOMEM;
185 
186 	irqc->base = of_iomap(node, 0);
187 	if (!irqc->base) {
188 		pr_err("%pOF: unable to map registers\n", node);
189 		kfree(irqc);
190 		return -EINVAL;
191 	}
192 
193 	irqc->chip.irq_ack = lpc32xx_irq_ack;
194 	irqc->chip.irq_mask = lpc32xx_irq_mask;
195 	irqc->chip.irq_unmask = lpc32xx_irq_unmask;
196 	irqc->chip.irq_set_type = lpc32xx_irq_set_type;
197 	if (is_mic)
198 		irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.mic", addr);
199 	else
200 		irqc->chip.name = kasprintf(GFP_KERNEL, "%08x.sic", addr);
201 
202 	irqc->domain = irq_domain_add_linear(node, NR_LPC32XX_IC_IRQS,
203 					     &lpc32xx_irq_domain_ops, irqc);
204 	if (!irqc->domain) {
205 		pr_err("unable to add irq domain\n");
206 		iounmap(irqc->base);
207 		kfree(irqc->chip.name);
208 		kfree(irqc);
209 		return -ENODEV;
210 	}
211 
212 	if (is_mic) {
213 		lpc32xx_mic_irqc = irqc;
214 		set_handle_irq(lpc32xx_handle_irq);
215 	} else {
216 		for (i = 0; i < of_irq_count(node); i++) {
217 			parent_irq = irq_of_parse_and_map(node, i);
218 			if (parent_irq)
219 				irq_set_chained_handler_and_data(parent_irq,
220 						 lpc32xx_sic_handler, irqc);
221 		}
222 	}
223 
224 	lpc32xx_ic_write(irqc, LPC32XX_INTC_MASK, 0x00);
225 	lpc32xx_ic_write(irqc, LPC32XX_INTC_POL,  0x00);
226 	lpc32xx_ic_write(irqc, LPC32XX_INTC_TYPE, 0x00);
227 
228 	return 0;
229 }
230 
231 IRQCHIP_DECLARE(nxp_lpc32xx_mic, "nxp,lpc3220-mic", lpc32xx_of_ic_init);
232 IRQCHIP_DECLARE(nxp_lpc32xx_sic, "nxp,lpc3220-sic", lpc32xx_of_ic_init);
233