1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Interrupt controller for the
4 * Communication Processor Module.
5 * Copyright (c) 1997 Dan error_act (dmalek@jlc.net)
6 */
7#include <linux/kernel.h>
8#include <linux/interrupt.h>
9#include <linux/irqdomain.h>
10#include <linux/platform_device.h>
11#include <asm/cpm1.h>
12
13struct cpm_pic_data {
14 cpic8xx_t __iomem *reg;
15 struct irq_domain *host;
16};
17
18static void cpm_mask_irq(struct irq_data *d)
19{
20 struct cpm_pic_data *data = irq_data_get_irq_chip_data(d);
21 unsigned int cpm_vec = (unsigned int)irqd_to_hwirq(d);
22
23 clrbits32(&data->reg->cpic_cimr, (1 << cpm_vec));
24}
25
26static void cpm_unmask_irq(struct irq_data *d)
27{
28 struct cpm_pic_data *data = irq_data_get_irq_chip_data(d);
29 unsigned int cpm_vec = (unsigned int)irqd_to_hwirq(d);
30
31 setbits32(&data->reg->cpic_cimr, (1 << cpm_vec));
32}
33
34static void cpm_end_irq(struct irq_data *d)
35{
36 struct cpm_pic_data *data = irq_data_get_irq_chip_data(d);
37 unsigned int cpm_vec = (unsigned int)irqd_to_hwirq(d);
38
39 out_be32(&data->reg->cpic_cisr, (1 << cpm_vec));
40}
41
42static struct irq_chip cpm_pic = {
43 .name = "CPM PIC",
44 .irq_mask = cpm_mask_irq,
45 .irq_unmask = cpm_unmask_irq,
46 .irq_eoi = cpm_end_irq,
47};
48
49static int cpm_get_irq(struct irq_desc *desc)
50{
51 struct cpm_pic_data *data = irq_desc_get_handler_data(desc);
52 int cpm_vec;
53
54 /*
55 * Get the vector by setting the ACK bit and then reading
56 * the register.
57 */
58 out_be16(&data->reg->cpic_civr, 1);
59 cpm_vec = in_be16(&data->reg->cpic_civr);
60 cpm_vec >>= 11;
61
62 return irq_find_mapping(domain: data->host, hwirq: cpm_vec);
63}
64
65static void cpm_cascade(struct irq_desc *desc)
66{
67 generic_handle_irq(cpm_get_irq(desc));
68}
69
70static int cpm_pic_host_map(struct irq_domain *h, unsigned int virq,
71 irq_hw_number_t hw)
72{
73 irq_set_chip_data(virq, h->host_data);
74 irq_set_status_flags(virq, IRQ_LEVEL);
75 irq_set_chip_and_handler(virq, &cpm_pic, handle_fasteoi_irq);
76 return 0;
77}
78
79static const struct irq_domain_ops cpm_pic_host_ops = {
80 .map = cpm_pic_host_map,
81};
82
83static int cpm_pic_probe(struct platform_device *pdev)
84{
85 struct device *dev = &pdev->dev;
86 struct resource *res;
87 int irq;
88 struct cpm_pic_data *data;
89
90 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
91 if (!res)
92 return -ENODEV;
93
94 data = devm_kzalloc(dev, size: sizeof(*data), GFP_KERNEL);
95 if (!data)
96 return -ENOMEM;
97
98 data->reg = devm_ioremap(dev, res->start, resource_size(res));
99 if (!data->reg)
100 return -ENODEV;
101
102 irq = platform_get_irq(pdev, 0);
103 if (irq < 0)
104 return irq;
105
106 /* Initialize the CPM interrupt controller. */
107 out_be32(&data->reg->cpic_cicr,
108 (CICR_SCD_SCC4 | CICR_SCC_SCC3 | CICR_SCB_SCC2 | CICR_SCA_SCC1) |
109 ((virq_to_hw(irq) / 2) << 13) | CICR_HP_MASK);
110
111 out_be32(&data->reg->cpic_cimr, 0);
112
113 data->host = irq_domain_create_linear(dev_fwnode(dev), size: 64, ops: &cpm_pic_host_ops, host_data: data);
114 if (!data->host)
115 return -ENODEV;
116
117 irq_set_handler_data(irq, data);
118 irq_set_chained_handler(irq, cpm_cascade);
119
120 setbits32(&data->reg->cpic_cicr, CICR_IEN);
121
122 return 0;
123}
124
125static const struct of_device_id cpm_pic_match[] = {
126 {
127 .compatible = "fsl,cpm1-pic",
128 }, {
129 .type = "cpm-pic",
130 .compatible = "CPM",
131 }, {},
132};
133
134static struct platform_driver cpm_pic_driver = {
135 .driver = {
136 .name = "cpm-pic",
137 .of_match_table = cpm_pic_match,
138 },
139 .probe = cpm_pic_probe,
140};
141
142static int __init cpm_pic_init(void)
143{
144 return platform_driver_register(&cpm_pic_driver);
145}
146arch_initcall(cpm_pic_init);
147
148/*
149 * The CPM can generate the error interrupt when there is a race condition
150 * between generating and masking interrupts. All we have to do is ACK it
151 * and return. This is a no-op function so we don't need any special
152 * tests in the interrupt handler.
153 */
154static irqreturn_t cpm_error_interrupt(int irq, void *dev)
155{
156 return IRQ_HANDLED;
157}
158
159static int cpm_error_probe(struct platform_device *pdev)
160{
161 int irq;
162
163 irq = platform_get_irq(pdev, 0);
164 if (irq < 0)
165 return irq;
166
167 return request_irq(irq, handler: cpm_error_interrupt, IRQF_NO_THREAD, name: "error", NULL);
168}
169
170static const struct of_device_id cpm_error_ids[] = {
171 { .compatible = "fsl,cpm1" },
172 { .type = "cpm" },
173 {},
174};
175
176static struct platform_driver cpm_error_driver = {
177 .driver = {
178 .name = "cpm-error",
179 .of_match_table = cpm_error_ids,
180 },
181 .probe = cpm_error_probe,
182};
183
184static int __init cpm_error_init(void)
185{
186 return platform_driver_register(&cpm_error_driver);
187}
188subsys_initcall(cpm_error_init);
189

source code of linux/arch/powerpc/platforms/8xx/cpm1-ic.c