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 long bits;
32 	unsigned int i;
33 
34 	regmap_read(map, TCU_REG_TFR, &irq_reg);
35 	regmap_read(map, TCU_REG_TMR, &irq_mask);
36 
37 	chained_irq_enter(irq_chip, desc);
38 
39 	irq_reg &= ~irq_mask;
40 	bits = irq_reg;
41 
42 	for_each_set_bit(i, &bits, 32)
43 		generic_handle_domain_irq(domain, i);
44 
45 	chained_irq_exit(irq_chip, desc);
46 }
47 
48 static void ingenic_tcu_gc_unmask_enable_reg(struct irq_data *d)
49 {
50 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
51 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
52 	struct regmap *map = gc->private;
53 	u32 mask = d->mask;
54 
55 	guard(raw_spinlock)(&gc->lock);
56 	regmap_write(map, ct->regs.ack, mask);
57 	regmap_write(map, ct->regs.enable, mask);
58 	*ct->mask_cache |= mask;
59 }
60 
61 static void ingenic_tcu_gc_mask_disable_reg(struct irq_data *d)
62 {
63 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
64 	struct irq_chip_type *ct = irq_data_get_chip_type(d);
65 	struct regmap *map = gc->private;
66 	u32 mask = d->mask;
67 
68 	guard(raw_spinlock)(&gc->lock);
69 	regmap_write(map, ct->regs.disable, mask);
70 	*ct->mask_cache &= ~mask;
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 	guard(raw_spinlock)(&gc->lock);
81 	regmap_write(map, ct->regs.ack, mask);
82 	regmap_write(map, ct->regs.disable, mask);
83 }
84 
85 static int __init ingenic_tcu_irq_init(struct device_node *np,
86 				       struct device_node *parent)
87 {
88 	struct irq_chip_generic *gc;
89 	struct irq_chip_type *ct;
90 	struct ingenic_tcu *tcu;
91 	struct regmap *map;
92 	unsigned int i;
93 	int ret, irqs;
94 
95 	map = device_node_to_regmap(np);
96 	if (IS_ERR(map))
97 		return PTR_ERR(map);
98 
99 	tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
100 	if (!tcu)
101 		return -ENOMEM;
102 
103 	tcu->map = map;
104 
105 	irqs = of_property_count_elems_of_size(np, "interrupts", sizeof(u32));
106 	if (irqs < 0 || irqs > ARRAY_SIZE(tcu->parent_irqs)) {
107 		pr_crit("%s: Invalid 'interrupts' property\n", __func__);
108 		ret = -EINVAL;
109 		goto err_free_tcu;
110 	}
111 
112 	tcu->nb_parent_irqs = irqs;
113 
114 	tcu->domain = irq_domain_create_linear(of_fwnode_handle(np), 32, &irq_generic_chip_ops,
115 					       NULL);
116 	if (!tcu->domain) {
117 		ret = -ENOMEM;
118 		goto err_free_tcu;
119 	}
120 
121 	ret = irq_alloc_domain_generic_chips(tcu->domain, 32, 1, "TCU",
122 					     handle_level_irq, 0,
123 					     IRQ_NOPROBE | IRQ_LEVEL, 0);
124 	if (ret) {
125 		pr_crit("%s: Invalid 'interrupts' property\n", __func__);
126 		goto out_domain_remove;
127 	}
128 
129 	gc = irq_get_domain_generic_chip(tcu->domain, 0);
130 	ct = gc->chip_types;
131 
132 	gc->wake_enabled = IRQ_MSK(32);
133 	gc->private = tcu->map;
134 
135 	ct->regs.disable = TCU_REG_TMSR;
136 	ct->regs.enable = TCU_REG_TMCR;
137 	ct->regs.ack = TCU_REG_TFCR;
138 	ct->chip.irq_unmask = ingenic_tcu_gc_unmask_enable_reg;
139 	ct->chip.irq_mask = ingenic_tcu_gc_mask_disable_reg;
140 	ct->chip.irq_mask_ack = ingenic_tcu_gc_mask_disable_reg_and_ack;
141 	ct->chip.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
142 
143 	/* Mask all IRQs by default */
144 	regmap_write(tcu->map, TCU_REG_TMSR, IRQ_MSK(32));
145 
146 	/*
147 	 * On JZ4740, timer 0 and timer 1 have their own interrupt line;
148 	 * timers 2-7 share one interrupt.
149 	 * On SoCs >= JZ4770, timer 5 has its own interrupt line;
150 	 * timers 0-4 and 6-7 share one single interrupt.
151 	 *
152 	 * To keep things simple, we just register the same handler to
153 	 * all parent interrupts. The handler will properly detect which
154 	 * channel fired the interrupt.
155 	 */
156 	for (i = 0; i < irqs; i++) {
157 		tcu->parent_irqs[i] = irq_of_parse_and_map(np, i);
158 		if (!tcu->parent_irqs[i]) {
159 			ret = -EINVAL;
160 			goto out_unmap_irqs;
161 		}
162 
163 		irq_set_chained_handler_and_data(tcu->parent_irqs[i],
164 						 ingenic_tcu_intc_cascade,
165 						 tcu->domain);
166 	}
167 
168 	return 0;
169 
170 out_unmap_irqs:
171 	for (; i > 0; i--)
172 		irq_dispose_mapping(tcu->parent_irqs[i - 1]);
173 out_domain_remove:
174 	irq_domain_remove(tcu->domain);
175 err_free_tcu:
176 	kfree(tcu);
177 	return ret;
178 }
179 IRQCHIP_DECLARE(jz4740_tcu_irq, "ingenic,jz4740-tcu", ingenic_tcu_irq_init);
180 IRQCHIP_DECLARE(jz4725b_tcu_irq, "ingenic,jz4725b-tcu", ingenic_tcu_irq_init);
181 IRQCHIP_DECLARE(jz4760_tcu_irq, "ingenic,jz4760-tcu", ingenic_tcu_irq_init);
182 IRQCHIP_DECLARE(jz4770_tcu_irq, "ingenic,jz4770-tcu", ingenic_tcu_irq_init);
183 IRQCHIP_DECLARE(x1000_tcu_irq, "ingenic,x1000-tcu", ingenic_tcu_irq_init);
184