1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2014-2015 Toradex AG
4 * Author: Stefan Agner <stefan@agner.ch>
5 *
6 * IRQ chip driver for MSCM interrupt router available on Vybrid SoC's.
7 * The interrupt router is between the CPU's interrupt controller and the
8 * peripheral. The router allows to route the peripheral interrupts to
9 * one of the two available CPU's on Vybrid VF6xx SoC's (Cortex-A5 or
10 * Cortex-M4). The router will be configured transparently on a IRQ
11 * request.
12 *
13 * o All peripheral interrupts of the Vybrid SoC can be routed to
14 * CPU 0, CPU 1 or both. The routing is useful for dual-core
15 * variants of Vybrid SoC such as VF6xx. This driver routes the
16 * requested interrupt to the CPU currently running on.
17 *
18 * o It is required to setup the interrupt router even on single-core
19 * variants of Vybrid.
20 */
21
22 #include <linux/cpu_pm.h>
23 #include <linux/io.h>
24 #include <linux/irq.h>
25 #include <linux/irqchip.h>
26 #include <linux/irqdomain.h>
27 #include <linux/mfd/syscon.h>
28 #include <dt-bindings/interrupt-controller/arm-gic.h>
29 #include <linux/of.h>
30 #include <linux/of_address.h>
31 #include <linux/slab.h>
32 #include <linux/regmap.h>
33
34 #define MSCM_CPxNUM 0x4
35
36 #define MSCM_IRSPRC(n) (0x80 + 2 * (n))
37 #define MSCM_IRSPRC_CPEN_MASK 0x3
38
39 #define MSCM_IRSPRC_NUM 112
40
41 struct vf610_mscm_ir_chip_data {
42 void __iomem *mscm_ir_base;
43 u16 cpu_mask;
44 u16 saved_irsprc[MSCM_IRSPRC_NUM];
45 bool is_nvic;
46 };
47
48 static struct vf610_mscm_ir_chip_data *mscm_ir_data;
49
vf610_mscm_ir_save(struct vf610_mscm_ir_chip_data * data)50 static inline void vf610_mscm_ir_save(struct vf610_mscm_ir_chip_data *data)
51 {
52 int i;
53
54 for (i = 0; i < MSCM_IRSPRC_NUM; i++)
55 data->saved_irsprc[i] = readw_relaxed(data->mscm_ir_base + MSCM_IRSPRC(i));
56 }
57
vf610_mscm_ir_restore(struct vf610_mscm_ir_chip_data * data)58 static inline void vf610_mscm_ir_restore(struct vf610_mscm_ir_chip_data *data)
59 {
60 int i;
61
62 for (i = 0; i < MSCM_IRSPRC_NUM; i++)
63 writew_relaxed(data->saved_irsprc[i], data->mscm_ir_base + MSCM_IRSPRC(i));
64 }
65
vf610_mscm_ir_notifier(struct notifier_block * self,unsigned long cmd,void * v)66 static int vf610_mscm_ir_notifier(struct notifier_block *self,
67 unsigned long cmd, void *v)
68 {
69 switch (cmd) {
70 case CPU_CLUSTER_PM_ENTER:
71 vf610_mscm_ir_save(mscm_ir_data);
72 break;
73 case CPU_CLUSTER_PM_ENTER_FAILED:
74 case CPU_CLUSTER_PM_EXIT:
75 vf610_mscm_ir_restore(mscm_ir_data);
76 break;
77 }
78
79 return NOTIFY_OK;
80 }
81
82 static struct notifier_block mscm_ir_notifier_block = {
83 .notifier_call = vf610_mscm_ir_notifier,
84 };
85
vf610_mscm_ir_enable(struct irq_data * data)86 static void vf610_mscm_ir_enable(struct irq_data *data)
87 {
88 irq_hw_number_t hwirq = data->hwirq;
89 struct vf610_mscm_ir_chip_data *chip_data = data->chip_data;
90 u16 irsprc;
91
92 irsprc = readw_relaxed(chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
93 irsprc &= MSCM_IRSPRC_CPEN_MASK;
94
95 WARN_ON(irsprc & ~chip_data->cpu_mask);
96
97 writew_relaxed(chip_data->cpu_mask,
98 chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
99
100 irq_chip_enable_parent(data);
101 }
102
vf610_mscm_ir_disable(struct irq_data * data)103 static void vf610_mscm_ir_disable(struct irq_data *data)
104 {
105 irq_hw_number_t hwirq = data->hwirq;
106 struct vf610_mscm_ir_chip_data *chip_data = data->chip_data;
107
108 writew_relaxed(0x0, chip_data->mscm_ir_base + MSCM_IRSPRC(hwirq));
109
110 irq_chip_disable_parent(data);
111 }
112
113 static struct irq_chip vf610_mscm_ir_irq_chip = {
114 .name = "mscm-ir",
115 .irq_mask = irq_chip_mask_parent,
116 .irq_unmask = irq_chip_unmask_parent,
117 .irq_eoi = irq_chip_eoi_parent,
118 .irq_enable = vf610_mscm_ir_enable,
119 .irq_disable = vf610_mscm_ir_disable,
120 .irq_retrigger = irq_chip_retrigger_hierarchy,
121 .irq_set_affinity = irq_chip_set_affinity_parent,
122 };
123
vf610_mscm_ir_domain_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * arg)124 static int vf610_mscm_ir_domain_alloc(struct irq_domain *domain, unsigned int virq,
125 unsigned int nr_irqs, void *arg)
126 {
127 int i;
128 irq_hw_number_t hwirq;
129 struct irq_fwspec *fwspec = arg;
130 struct irq_fwspec parent_fwspec;
131
132 if (!irq_domain_get_of_node(domain->parent))
133 return -EINVAL;
134
135 if (fwspec->param_count != 2)
136 return -EINVAL;
137
138 hwirq = fwspec->param[0];
139 for (i = 0; i < nr_irqs; i++)
140 irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
141 &vf610_mscm_ir_irq_chip,
142 domain->host_data);
143
144 parent_fwspec.fwnode = domain->parent->fwnode;
145
146 if (mscm_ir_data->is_nvic) {
147 parent_fwspec.param_count = 1;
148 parent_fwspec.param[0] = fwspec->param[0];
149 } else {
150 parent_fwspec.param_count = 3;
151 parent_fwspec.param[0] = GIC_SPI;
152 parent_fwspec.param[1] = fwspec->param[0];
153 parent_fwspec.param[2] = fwspec->param[1];
154 }
155
156 return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
157 &parent_fwspec);
158 }
159
vf610_mscm_ir_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)160 static int vf610_mscm_ir_domain_translate(struct irq_domain *d,
161 struct irq_fwspec *fwspec,
162 unsigned long *hwirq,
163 unsigned int *type)
164 {
165 if (WARN_ON(fwspec->param_count < 2))
166 return -EINVAL;
167 *hwirq = fwspec->param[0];
168 *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
169 return 0;
170 }
171
172 static const struct irq_domain_ops mscm_irq_domain_ops = {
173 .translate = vf610_mscm_ir_domain_translate,
174 .alloc = vf610_mscm_ir_domain_alloc,
175 .free = irq_domain_free_irqs_common,
176 };
177
vf610_mscm_ir_of_init(struct device_node * node,struct device_node * parent)178 static int __init vf610_mscm_ir_of_init(struct device_node *node,
179 struct device_node *parent)
180 {
181 struct irq_domain *domain, *domain_parent;
182 struct regmap *mscm_cp_regmap;
183 int ret, cpuid;
184
185 domain_parent = irq_find_host(parent);
186 if (!domain_parent) {
187 pr_err("vf610_mscm_ir: interrupt-parent not found\n");
188 return -EINVAL;
189 }
190
191 mscm_ir_data = kzalloc(sizeof(*mscm_ir_data), GFP_KERNEL);
192 if (!mscm_ir_data)
193 return -ENOMEM;
194
195 mscm_ir_data->mscm_ir_base = of_io_request_and_map(node, 0, "mscm-ir");
196 if (IS_ERR(mscm_ir_data->mscm_ir_base)) {
197 pr_err("vf610_mscm_ir: unable to map mscm register\n");
198 ret = PTR_ERR(mscm_ir_data->mscm_ir_base);
199 goto out_free;
200 }
201
202 mscm_cp_regmap = syscon_regmap_lookup_by_phandle(node, "fsl,cpucfg");
203 if (IS_ERR(mscm_cp_regmap)) {
204 ret = PTR_ERR(mscm_cp_regmap);
205 pr_err("vf610_mscm_ir: regmap lookup for cpucfg failed\n");
206 goto out_unmap;
207 }
208
209 regmap_read(mscm_cp_regmap, MSCM_CPxNUM, &cpuid);
210 mscm_ir_data->cpu_mask = 0x1 << cpuid;
211
212 domain = irq_domain_add_hierarchy(domain_parent, 0,
213 MSCM_IRSPRC_NUM, node,
214 &mscm_irq_domain_ops, mscm_ir_data);
215 if (!domain) {
216 ret = -ENOMEM;
217 goto out_unmap;
218 }
219
220 if (of_device_is_compatible(irq_domain_get_of_node(domain->parent),
221 "arm,armv7m-nvic"))
222 mscm_ir_data->is_nvic = true;
223
224 cpu_pm_register_notifier(&mscm_ir_notifier_block);
225
226 return 0;
227
228 out_unmap:
229 iounmap(mscm_ir_data->mscm_ir_base);
230 out_free:
231 kfree(mscm_ir_data);
232 return ret;
233 }
234 IRQCHIP_DECLARE(vf610_mscm_ir, "fsl,vf610-mscm-ir", vf610_mscm_ir_of_init);
235