1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * JZ47xx SoCs TCU IRQ driver
4  * Copyright (C) 2019 Paul Cercueil <paul@crapouillou.net>
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/interrupt.h>
9 #include <linux/irqchip.h>
10 #include <linux/irqchip/chained_irq.h>
11 #include <linux/mfd/ingenic-tcu.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/of_irq.h>
14 #include <linux/regmap.h>
15 
16 struct ingenic_tcu {
17 	struct regmap *map;
18 	struct clk *clk;
19 	struct irq_domain *domain;
20 	unsigned int nb_parent_irqs;
21 	u32 parent_irqs[3];
22 };
23 
24 static void ingenic_tcu_intc_cascade(struct irq_desc *desc)
25 {
26 	struct irq_chip *irq_chip = irq_data_get_irq_chip(&desc->irq_data);
27 	struct irq_domain *domain = irq_desc_get_handler_data(desc);
28 	struct irq_chip_generic *gc = irq_get_domain_generic_chip(domain, 0);
29 	struct regmap *map = gc->private;
30 	uint32_t irq_reg, irq_mask;
31 	unsigned int i;
32 
33 	regmap_read(map, TCU_REG_TFR, &irq_reg);
34 	regmap_read(map, TCU_REG_TMR, &irq_mask);
35 
36 	chained_irq_enter(irq_chip, desc);
37 
38 	irq_reg &= ~irq_mask;
39 
40 	for_each_set_bit(i, (unsigned long *)&irq_reg, 32)
41 		generic_handle_irq(irq_linear_revmap(domain, i));
42 
43 	chained_irq_exit(irq_chip, desc);
44 }
45 
46 static void ingenic_tcu_gc_unmask_enable_reg(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 	struct regmap *map = gc->private;
51 	u32 mask = d->mask;
52 
53 	irq_gc_lock(gc);
54 	regmap_write(map, ct->regs.ack, mask);
55 	regmap_write(map, ct->regs.enable, mask);
56 	*ct->mask_cache |= mask;
57 	irq_gc_unlock(gc);
58 }
59 
60 static void ingenic_tcu_gc_mask_disable_reg(struct irq_data *d)
61 {
62 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
63 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
64 	struct regmap *map = gc->private;
65 	u32 mask = d->mask;
66 
67 	irq_gc_lock(gc);
68 	regmap_write(map, ct->regs.disable, mask);
69 	*ct->mask_cache &= ~mask;
70 	irq_gc_unlock(gc);
71 }
72 
73 static void ingenic_tcu_gc_mask_disable_reg_and_ack(struct irq_data *d)
74 {
75 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
76 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
77 	struct regmap *map = gc->private;
78 	u32 mask = d->mask;
79 
80 	irq_gc_lock(gc);
81 	regmap_write(map, ct->regs.ack, mask);
82 	regmap_write(map, ct->regs.disable, mask);
83 	irq_gc_unlock(gc);
84 }
85 
86 static int __init ingenic_tcu_irq_init(struct device_node *np,
87 				       struct device_node *parent)
88 {
89 	struct irq_chip_generic *gc;
90 	struct irq_chip_type *ct;
91 	struct ingenic_tcu *tcu;
92 	struct regmap *map;
93 	unsigned int i;
94 	int ret, irqs;
95 
96 	map = device_node_to_regmap(np);
97 	if (IS_ERR(map))
98 		return PTR_ERR(map);
99 
100 	tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
101 	if (!tcu)
102 		return -ENOMEM;
103 
104 	tcu->map = map;
105 
106 	irqs = of_property_count_elems_of_size(np, "interrupts", sizeof(u32));
107 	if (irqs < 0 || irqs > ARRAY_SIZE(tcu->parent_irqs)) {
108 		pr_crit("%s: Invalid 'interrupts' property\n", __func__);
109 		ret = -EINVAL;
110 		goto err_free_tcu;
111 	}
112 
113 	tcu->nb_parent_irqs = irqs;
114 
115 	tcu->domain = irq_domain_add_linear(np, 32, &irq_generic_chip_ops,
116 					    NULL);
117 	if (!tcu->domain) {
118 		ret = -ENOMEM;
119 		goto err_free_tcu;
120 	}
121 
122 	ret = irq_alloc_domain_generic_chips(tcu->domain, 32, 1, "TCU",
123 					     handle_level_irq, 0,
124 					     IRQ_NOPROBE | IRQ_LEVEL, 0);
125 	if (ret) {
126 		pr_crit("%s: Invalid 'interrupts' property\n", __func__);
127 		goto out_domain_remove;
128 	}
129 
130 	gc = irq_get_domain_generic_chip(tcu->domain, 0);
131 	ct = gc->chip_types;
132 
133 	gc->wake_enabled = IRQ_MSK(32);
134 	gc->private = tcu->map;
135 
136 	ct->regs.disable = TCU_REG_TMSR;
137 	ct->regs.enable = TCU_REG_TMCR;
138 	ct->regs.ack = TCU_REG_TFCR;
139 	ct->chip.irq_unmask = ingenic_tcu_gc_unmask_enable_reg;
140 	ct->chip.irq_mask = ingenic_tcu_gc_mask_disable_reg;
141 	ct->chip.irq_mask_ack = ingenic_tcu_gc_mask_disable_reg_and_ack;
142 	ct->chip.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
143 
144 	/* Mask all IRQs by default */
145 	regmap_write(tcu->map, TCU_REG_TMSR, IRQ_MSK(32));
146 
147 	/*
148 	 * On JZ4740, timer 0 and timer 1 have their own interrupt line;
149 	 * timers 2-7 share one interrupt.
150 	 * On SoCs >= JZ4770, timer 5 has its own interrupt line;
151 	 * timers 0-4 and 6-7 share one single interrupt.
152 	 *
153 	 * To keep things simple, we just register the same handler to
154 	 * all parent interrupts. The handler will properly detect which
155 	 * channel fired the interrupt.
156 	 */
157 	for (i = 0; i < irqs; i++) {
158 		tcu->parent_irqs[i] = irq_of_parse_and_map(np, i);
159 		if (!tcu->parent_irqs[i]) {
160 			ret = -EINVAL;
161 			goto out_unmap_irqs;
162 		}
163 
164 		irq_set_chained_handler_and_data(tcu->parent_irqs[i],
165 						 ingenic_tcu_intc_cascade,
166 						 tcu->domain);
167 	}
168 
169 	return 0;
170 
171 out_unmap_irqs:
172 	for (; i > 0; i--)
173 		irq_dispose_mapping(tcu->parent_irqs[i - 1]);
174 out_domain_remove:
175 	irq_domain_remove(tcu->domain);
176 err_free_tcu:
177 	kfree(tcu);
178 	return ret;
179 }
180 IRQCHIP_DECLARE(jz4740_tcu_irq, "ingenic,jz4740-tcu", ingenic_tcu_irq_init);
181 IRQCHIP_DECLARE(jz4725b_tcu_irq, "ingenic,jz4725b-tcu", ingenic_tcu_irq_init);
182 IRQCHIP_DECLARE(jz4770_tcu_irq, "ingenic,jz4770-tcu", ingenic_tcu_irq_init);
183