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1 /*
2  * Allwinner A20/A31 SoCs NMI IRQ chip driver.
3  *
4  * Carlo Caione <carlo.caione@gmail.com>
5  *
6  * This file is licensed under the terms of the GNU General Public
7  * License version 2.  This program is licensed "as is" without any
8  * warranty of any kind, whether express or implied.
9  */
10 
11 #define DRV_NAME	"sunxi-8i-nmi"
12 #define pr_fmt(fmt)	DRV_NAME ": " fmt
13 
14 #include <linux/bitops.h>
15 #include <linux/device.h>
16 #include <linux/io.h>
17 #include <linux/irq.h>
18 #include <linux/interrupt.h>
19 #include <linux/irqdomain.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_address.h>
22 #include <linux/of_platform.h>
23 #include <linux/irqchip.h>
24 #include <linux/irqchip/chained_irq.h>
25 #include <linux/syscore_ops.h>
26 #include <linux/pinctrl/consumer.h>
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/platform_device.h>
30 
31 #define SUNXI_NMI_SRC_TYPE_MASK	0x00000003
32 
33 enum {
34 	SUNXI_SRC_TYPE_LEVEL_LOW = 0,
35 	SUNXI_SRC_TYPE_EDGE_FALLING,
36 	SUNXI_SRC_TYPE_LEVEL_HIGH,
37 	SUNXI_SRC_TYPE_EDGE_RISING,
38 };
39 
40 struct sunxi_sc_nmi_reg_offs {
41 	u32 ctrl;
42 	u32 pend;
43 	u32 enable;
44 };
45 
46 static struct sunxi_sc_nmi_reg_offs sun8i_reg_offs = {
47 	.ctrl	= 0x00,
48 	.pend	= 0x08,
49 	.enable	= 0x04,
50 };
51 
sunxi_sc_nmi_write(struct irq_chip_generic * gc,u32 off,u32 val)52 static inline void sunxi_sc_nmi_write(struct irq_chip_generic *gc, u32 off,
53 				      u32 val)
54 {
55 	irq_reg_writel(gc, val, off);
56 }
57 
sunxi_sc_nmi_read(struct irq_chip_generic * gc,u32 off)58 static inline u32 sunxi_sc_nmi_read(struct irq_chip_generic *gc, u32 off)
59 {
60 	return irq_reg_readl(gc, off);
61 }
62 
sunxi_sc_nmi_handle_irq(struct irq_desc * desc)63 static void sunxi_sc_nmi_handle_irq(struct irq_desc *desc)
64 {
65 	struct irq_domain *domain = irq_desc_get_handler_data(desc);
66 	struct irq_chip *chip = irq_desc_get_chip(desc);
67 	unsigned int virq = irq_find_mapping(domain, 0);
68 
69 	chained_irq_enter(chip, desc);
70 	generic_handle_irq(virq);
71 	chained_irq_exit(chip, desc);
72 }
73 
sunxi_sc_nmi_set_type(struct irq_data * data,unsigned int flow_type)74 static int sunxi_sc_nmi_set_type(struct irq_data *data, unsigned int flow_type)
75 {
76 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
77 	struct irq_chip_type *ct = gc->chip_types;
78 	u32 src_type_reg;
79 	u32 ctrl_off = ct->regs.type;
80 	unsigned int src_type;
81 	unsigned int i;
82 
83 	irq_gc_lock(gc);
84 
85 	switch (flow_type & IRQF_TRIGGER_MASK) {
86 	case IRQ_TYPE_EDGE_FALLING:
87 		src_type = SUNXI_SRC_TYPE_EDGE_FALLING;
88 		break;
89 	case IRQ_TYPE_EDGE_RISING:
90 		src_type = SUNXI_SRC_TYPE_EDGE_RISING;
91 		break;
92 	case IRQ_TYPE_LEVEL_HIGH:
93 		src_type = SUNXI_SRC_TYPE_LEVEL_HIGH;
94 		break;
95 	case IRQ_TYPE_NONE:
96 	case IRQ_TYPE_LEVEL_LOW:
97 		src_type = SUNXI_SRC_TYPE_LEVEL_LOW;
98 		break;
99 	default:
100 		irq_gc_unlock(gc);
101 		pr_err("Cannot assign multiple trigger modes to IRQ %d.\n",
102 			data->irq);
103 		return -EBADR;
104 	}
105 
106 	irqd_set_trigger_type(data, flow_type);
107 	irq_setup_alt_chip(data, flow_type);
108 
109 	for (i = 0; i < gc->num_ct; i++, ct++)
110 		if (ct->type & flow_type)
111 			ctrl_off = ct->regs.type;
112 
113 	src_type_reg = sunxi_sc_nmi_read(gc, ctrl_off);
114 	src_type_reg &= ~SUNXI_NMI_SRC_TYPE_MASK;
115 	src_type_reg |= src_type;
116 	sunxi_sc_nmi_write(gc, ctrl_off, src_type_reg);
117 
118 	irq_gc_unlock(gc);
119 
120 	return IRQ_SET_MASK_OK;
121 }
122 
sunxi_nmi_pad_control(struct device_node * node)123 static void sunxi_nmi_pad_control(struct device_node *node)
124 {
125 	u32 v;
126 	u32 __iomem *pad;
127 
128 	/* if we read pad-control-v1, the we use the addr to contorl nmi */
129 	if (of_property_read_u32(node, "pad-control-v1", &v))
130 		return;
131 
132 	pad = ioremap(v, 4);
133 	*pad = *pad & ~BIT(0);
134 	iounmap(pad);
135 }
136 
137 /*
138  * on some standby, the prcm control register can lowpower down
139  * so it must resume the register value first
140  */
141 static struct irq_chip_generic *sys_gc;
142 static struct sunxi_sc_nmi_reg_offs *sys_reg_offs;
143 static uint32_t sys_vaule;
sunxi_nmi_suspend(void)144 static int sunxi_nmi_suspend(void)
145 {
146 	sys_vaule = sunxi_sc_nmi_read(sys_gc, sys_reg_offs->enable);
147 	return 0;
148 }
149 
sunxi_nmi_resume(void)150 static void sunxi_nmi_resume(void)
151 {
152 	sunxi_sc_nmi_write(sys_gc, sys_reg_offs->enable, sys_vaule);
153 }
154 
155 static struct syscore_ops sunxi_nmi_syscore_ops = {
156 	.suspend = sunxi_nmi_suspend,
157 	.resume = sunxi_nmi_resume,
158 };
159 
sunxi_sc_nmi_irq_init(struct device_node * node,struct sunxi_sc_nmi_reg_offs * reg_offs)160 static int sunxi_sc_nmi_irq_init(struct device_node *node,
161 					struct sunxi_sc_nmi_reg_offs *reg_offs)
162 {
163 	struct irq_domain *domain;
164 	struct irq_chip_generic *gc;
165 	unsigned int irq;
166 	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
167 	int ret;
168 
169 
170 	domain = irq_domain_add_linear(node, 1, &irq_generic_chip_ops, NULL);
171 	if (!domain) {
172 		pr_err("Could not register interrupt domain.\n");
173 		return -ENOMEM;
174 	}
175 
176 	ret = irq_alloc_domain_generic_chips(domain, 1, 2, DRV_NAME,
177 					     handle_fasteoi_irq, clr, 0,
178 					     IRQ_GC_INIT_MASK_CACHE);
179 	if (ret) {
180 		pr_err("Could not allocate generic interrupt chip.\n");
181 		goto fail_irqd_remove;
182 	}
183 
184 	irq = irq_of_parse_and_map(node, 0);
185 	if (irq <= 0) {
186 		pr_err("unable to parse irq\n");
187 		ret = -EINVAL;
188 		goto fail_irqd_remove;
189 	}
190 
191 	gc = irq_get_domain_generic_chip(domain, 0);
192 	gc->reg_base = of_io_request_and_map(node, 0, of_node_full_name(node));
193 	if (IS_ERR(gc->reg_base)) {
194 		pr_err("unable to map resource\n");
195 		ret = PTR_ERR(gc->reg_base);
196 		goto fail_irqd_remove;
197 	}
198 
199 	gc->chip_types[0].type			= IRQ_TYPE_LEVEL_MASK;
200 	gc->chip_types[0].chip.irq_mask		= irq_gc_mask_clr_bit;
201 	gc->chip_types[0].chip.irq_unmask	= irq_gc_mask_set_bit;
202 	gc->chip_types[0].chip.irq_eoi		= irq_gc_ack_set_bit;
203 	gc->chip_types[0].chip.irq_set_type	= sunxi_sc_nmi_set_type;
204 	gc->chip_types[0].chip.flags 		= IRQCHIP_EOI_THREADED |
205 							IRQCHIP_EOI_IF_HANDLED |
206 							IRQCHIP_SKIP_SET_WAKE;
207 	gc->chip_types[0].regs.ack		= reg_offs->pend;
208 	gc->chip_types[0].regs.mask		= reg_offs->enable;
209 	gc->chip_types[0].regs.type		= reg_offs->ctrl;
210 
211 	gc->chip_types[1].type			= IRQ_TYPE_EDGE_BOTH;
212 	gc->chip_types[1].chip.name		= gc->chip_types[0].chip.name;
213 	gc->chip_types[1].chip.irq_ack		= irq_gc_ack_set_bit;
214 	gc->chip_types[1].chip.irq_mask		= irq_gc_mask_clr_bit;
215 	gc->chip_types[1].chip.irq_unmask	= irq_gc_mask_set_bit;
216 	gc->chip_types[1].chip.irq_set_type	= sunxi_sc_nmi_set_type;
217 	gc->chip_types[1].regs.ack		= reg_offs->pend;
218 	gc->chip_types[1].regs.mask		= reg_offs->enable;
219 	gc->chip_types[1].regs.type		= reg_offs->ctrl;
220 	gc->chip_types[1].handler		= handle_edge_irq;
221 
222 	sunxi_sc_nmi_write(gc, reg_offs->enable, 0);
223 	sunxi_sc_nmi_write(gc, reg_offs->pend, 0x1);
224 
225 	sunxi_nmi_pad_control(node);
226 	sys_gc = gc;
227 	sys_reg_offs = reg_offs;
228 	register_syscore_ops(&sunxi_nmi_syscore_ops);
229 
230 	irq_set_chained_handler_and_data(irq, sunxi_sc_nmi_handle_irq, domain);
231 
232 	return 0;
233 
234 fail_irqd_remove:
235 	irq_domain_remove(domain);
236 
237 	return ret;
238 }
239 
sunxi_irq_nmi_probe(struct platform_device * pdev)240 static int sunxi_irq_nmi_probe(struct platform_device *pdev)
241 {
242 	struct pinctrl *pctrl;
243 	struct pinctrl_state *pctrl_state = NULL;
244 
245 	pctrl = devm_pinctrl_get(&pdev->dev);
246 	if (!IS_ERR_OR_NULL(pctrl)) {
247 		pctrl_state = pinctrl_lookup_state(pctrl, "default");
248 
249 		pinctrl_select_state(pctrl, pctrl_state);
250 	}
251 
252 	return sunxi_sc_nmi_irq_init(pdev->dev.of_node, &sun8i_reg_offs);
253 }
254 
sunxi_irq_nmi_remove(struct platform_device * pdev)255 static int sunxi_irq_nmi_remove(struct platform_device *pdev)
256 {
257 	struct device_node *node = pdev->dev.of_node;
258 	struct resource res;
259 
260 	unregister_syscore_ops(&sunxi_nmi_syscore_ops);
261 	iounmap(sys_gc->reg_base);
262 	of_address_to_resource(node, 0, &res);
263 	release_mem_region(res.start, resource_size(&res));
264 	irq_domain_remove(sys_gc->domain);
265 
266 	return 0;
267 }
268 
269 static struct of_device_id sunxi_irq_nmi_match[] = {
270 	{ .compatible = "allwinner,sun8i-nmi" },
271 	{}
272 };
273 
274 static struct platform_driver sunxi_irq_nmi_driver = {
275 	.probe = sunxi_irq_nmi_probe,
276 	.remove = sunxi_irq_nmi_remove,
277 	.driver = {
278 		.name = "sunxi_irq_nmi",
279 		.owner = THIS_MODULE,
280 		.of_match_table = sunxi_irq_nmi_match,
281 	},
282 };
283 
sun8i_nmi_irq_init(void)284 static int __init sun8i_nmi_irq_init(void)
285 {
286 	return platform_driver_register(&sunxi_irq_nmi_driver);
287 }
288 postcore_initcall_sync(sun8i_nmi_irq_init);
289 
sun8i_nmi_irq_exit(void)290 static void __exit sun8i_nmi_irq_exit(void)
291 {
292 	platform_driver_unregister(&sunxi_irq_nmi_driver);
293 }
294 module_exit(sun8i_nmi_irq_exit);
295 
296 MODULE_AUTHOR("lihuaxing");
297 MODULE_DESCRIPTION("Allwinner nmi irq");
298 MODULE_LICENSE("GPL");
299 MODULE_VERSION("1.0.0");
300