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-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/irqchip.h>
23 #include <linux/irqchip/chained_irq.h>
24
25 #define SUNXI_NMI_SRC_TYPE_MASK 0x00000003
26
27 #define SUNXI_NMI_IRQ_BIT BIT(0)
28
29 /*
30 * For deprecated sun6i-a31-sc-nmi compatible.
31 */
32 #define SUN6I_NMI_CTRL 0x00
33 #define SUN6I_NMI_PENDING 0x04
34 #define SUN6I_NMI_ENABLE 0x34
35
36 #define SUN7I_NMI_CTRL 0x00
37 #define SUN7I_NMI_PENDING 0x04
38 #define SUN7I_NMI_ENABLE 0x08
39
40 #define SUN9I_NMI_CTRL 0x00
41 #define SUN9I_NMI_ENABLE 0x04
42 #define SUN9I_NMI_PENDING 0x08
43
44 enum {
45 SUNXI_SRC_TYPE_LEVEL_LOW = 0,
46 SUNXI_SRC_TYPE_EDGE_FALLING,
47 SUNXI_SRC_TYPE_LEVEL_HIGH,
48 SUNXI_SRC_TYPE_EDGE_RISING,
49 };
50
51 struct sunxi_sc_nmi_reg_offs {
52 u32 ctrl;
53 u32 pend;
54 u32 enable;
55 };
56
57 static const struct sunxi_sc_nmi_reg_offs sun6i_reg_offs __initconst = {
58 .ctrl = SUN6I_NMI_CTRL,
59 .pend = SUN6I_NMI_PENDING,
60 .enable = SUN6I_NMI_ENABLE,
61 };
62
63 static const struct sunxi_sc_nmi_reg_offs sun7i_reg_offs __initconst = {
64 .ctrl = SUN7I_NMI_CTRL,
65 .pend = SUN7I_NMI_PENDING,
66 .enable = SUN7I_NMI_ENABLE,
67 };
68
69 static const struct sunxi_sc_nmi_reg_offs sun9i_reg_offs __initconst = {
70 .ctrl = SUN9I_NMI_CTRL,
71 .pend = SUN9I_NMI_PENDING,
72 .enable = SUN9I_NMI_ENABLE,
73 };
74
sunxi_sc_nmi_write(struct irq_chip_generic * gc,u32 off,u32 val)75 static inline void sunxi_sc_nmi_write(struct irq_chip_generic *gc, u32 off,
76 u32 val)
77 {
78 irq_reg_writel(gc, val, off);
79 }
80
sunxi_sc_nmi_read(struct irq_chip_generic * gc,u32 off)81 static inline u32 sunxi_sc_nmi_read(struct irq_chip_generic *gc, u32 off)
82 {
83 return irq_reg_readl(gc, off);
84 }
85
sunxi_sc_nmi_handle_irq(struct irq_desc * desc)86 static void sunxi_sc_nmi_handle_irq(struct irq_desc *desc)
87 {
88 struct irq_domain *domain = irq_desc_get_handler_data(desc);
89 struct irq_chip *chip = irq_desc_get_chip(desc);
90
91 chained_irq_enter(chip, desc);
92 generic_handle_domain_irq(domain, 0);
93 chained_irq_exit(chip, desc);
94 }
95
sunxi_sc_nmi_set_type(struct irq_data * data,unsigned int flow_type)96 static int sunxi_sc_nmi_set_type(struct irq_data *data, unsigned int flow_type)
97 {
98 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
99 struct irq_chip_type *ct = gc->chip_types;
100 u32 src_type_reg;
101 u32 ctrl_off = ct->regs.type;
102 unsigned int src_type;
103 unsigned int i;
104
105 irq_gc_lock(gc);
106
107 switch (flow_type & IRQF_TRIGGER_MASK) {
108 case IRQ_TYPE_EDGE_FALLING:
109 src_type = SUNXI_SRC_TYPE_EDGE_FALLING;
110 break;
111 case IRQ_TYPE_EDGE_RISING:
112 src_type = SUNXI_SRC_TYPE_EDGE_RISING;
113 break;
114 case IRQ_TYPE_LEVEL_HIGH:
115 src_type = SUNXI_SRC_TYPE_LEVEL_HIGH;
116 break;
117 case IRQ_TYPE_NONE:
118 case IRQ_TYPE_LEVEL_LOW:
119 src_type = SUNXI_SRC_TYPE_LEVEL_LOW;
120 break;
121 default:
122 irq_gc_unlock(gc);
123 pr_err("Cannot assign multiple trigger modes to IRQ %d.\n",
124 data->irq);
125 return -EBADR;
126 }
127
128 irqd_set_trigger_type(data, flow_type);
129 irq_setup_alt_chip(data, flow_type);
130
131 for (i = 0; i < gc->num_ct; i++, ct++)
132 if (ct->type & flow_type)
133 ctrl_off = ct->regs.type;
134
135 src_type_reg = sunxi_sc_nmi_read(gc, ctrl_off);
136 src_type_reg &= ~SUNXI_NMI_SRC_TYPE_MASK;
137 src_type_reg |= src_type;
138 sunxi_sc_nmi_write(gc, ctrl_off, src_type_reg);
139
140 irq_gc_unlock(gc);
141
142 return IRQ_SET_MASK_OK;
143 }
144
sunxi_sc_nmi_irq_init(struct device_node * node,const struct sunxi_sc_nmi_reg_offs * reg_offs)145 static int __init sunxi_sc_nmi_irq_init(struct device_node *node,
146 const struct sunxi_sc_nmi_reg_offs *reg_offs)
147 {
148 struct irq_domain *domain;
149 struct irq_chip_generic *gc;
150 unsigned int irq;
151 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
152 int ret;
153
154
155 domain = irq_domain_add_linear(node, 1, &irq_generic_chip_ops, NULL);
156 if (!domain) {
157 pr_err("Could not register interrupt domain.\n");
158 return -ENOMEM;
159 }
160
161 ret = irq_alloc_domain_generic_chips(domain, 1, 2, DRV_NAME,
162 handle_fasteoi_irq, clr, 0,
163 IRQ_GC_INIT_MASK_CACHE);
164 if (ret) {
165 pr_err("Could not allocate generic interrupt chip.\n");
166 goto fail_irqd_remove;
167 }
168
169 irq = irq_of_parse_and_map(node, 0);
170 if (irq <= 0) {
171 pr_err("unable to parse irq\n");
172 ret = -EINVAL;
173 goto fail_irqd_remove;
174 }
175
176 gc = irq_get_domain_generic_chip(domain, 0);
177 gc->reg_base = of_io_request_and_map(node, 0, of_node_full_name(node));
178 if (IS_ERR(gc->reg_base)) {
179 pr_err("unable to map resource\n");
180 ret = PTR_ERR(gc->reg_base);
181 goto fail_irqd_remove;
182 }
183
184 gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
185 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
186 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
187 gc->chip_types[0].chip.irq_eoi = irq_gc_ack_set_bit;
188 gc->chip_types[0].chip.irq_set_type = sunxi_sc_nmi_set_type;
189 gc->chip_types[0].chip.flags = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED;
190 gc->chip_types[0].regs.ack = reg_offs->pend;
191 gc->chip_types[0].regs.mask = reg_offs->enable;
192 gc->chip_types[0].regs.type = reg_offs->ctrl;
193
194 gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
195 gc->chip_types[1].chip.name = gc->chip_types[0].chip.name;
196 gc->chip_types[1].chip.irq_ack = irq_gc_ack_set_bit;
197 gc->chip_types[1].chip.irq_mask = irq_gc_mask_clr_bit;
198 gc->chip_types[1].chip.irq_unmask = irq_gc_mask_set_bit;
199 gc->chip_types[1].chip.irq_set_type = sunxi_sc_nmi_set_type;
200 gc->chip_types[1].regs.ack = reg_offs->pend;
201 gc->chip_types[1].regs.mask = reg_offs->enable;
202 gc->chip_types[1].regs.type = reg_offs->ctrl;
203 gc->chip_types[1].handler = handle_edge_irq;
204
205 /* Disable any active interrupts */
206 sunxi_sc_nmi_write(gc, reg_offs->enable, 0);
207
208 /* Clear any pending NMI interrupts */
209 sunxi_sc_nmi_write(gc, reg_offs->pend, SUNXI_NMI_IRQ_BIT);
210
211 irq_set_chained_handler_and_data(irq, sunxi_sc_nmi_handle_irq, domain);
212
213 return 0;
214
215 fail_irqd_remove:
216 irq_domain_remove(domain);
217
218 return ret;
219 }
220
sun6i_sc_nmi_irq_init(struct device_node * node,struct device_node * parent)221 static int __init sun6i_sc_nmi_irq_init(struct device_node *node,
222 struct device_node *parent)
223 {
224 return sunxi_sc_nmi_irq_init(node, &sun6i_reg_offs);
225 }
226 IRQCHIP_DECLARE(sun6i_sc_nmi, "allwinner,sun6i-a31-sc-nmi", sun6i_sc_nmi_irq_init);
227
sun7i_sc_nmi_irq_init(struct device_node * node,struct device_node * parent)228 static int __init sun7i_sc_nmi_irq_init(struct device_node *node,
229 struct device_node *parent)
230 {
231 return sunxi_sc_nmi_irq_init(node, &sun7i_reg_offs);
232 }
233 IRQCHIP_DECLARE(sun7i_sc_nmi, "allwinner,sun7i-a20-sc-nmi", sun7i_sc_nmi_irq_init);
234
sun9i_nmi_irq_init(struct device_node * node,struct device_node * parent)235 static int __init sun9i_nmi_irq_init(struct device_node *node,
236 struct device_node *parent)
237 {
238 return sunxi_sc_nmi_irq_init(node, &sun9i_reg_offs);
239 }
240 IRQCHIP_DECLARE(sun9i_nmi, "allwinner,sun9i-a80-nmi", sun9i_nmi_irq_init);
241