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/of_platform.h>
23 #include <linux/irqchip.h>
24 #include <linux/irqchip/chained_irq.h>
25
26 #define SUNXI_NMI_SRC_TYPE_MASK 0x00000003
27
28 #define SUNXI_NMI_IRQ_BIT BIT(0)
29
30 /*
31 * For deprecated sun6i-a31-sc-nmi compatible.
32 */
33 #define SUN6I_NMI_CTRL 0x00
34 #define SUN6I_NMI_PENDING 0x04
35 #define SUN6I_NMI_ENABLE 0x34
36
37 #define SUN7I_NMI_CTRL 0x00
38 #define SUN7I_NMI_PENDING 0x04
39 #define SUN7I_NMI_ENABLE 0x08
40
41 #define SUN9I_NMI_CTRL 0x00
42 #define SUN9I_NMI_ENABLE 0x04
43 #define SUN9I_NMI_PENDING 0x08
44
45 enum {
46 SUNXI_SRC_TYPE_LEVEL_LOW = 0,
47 SUNXI_SRC_TYPE_EDGE_FALLING,
48 SUNXI_SRC_TYPE_LEVEL_HIGH,
49 SUNXI_SRC_TYPE_EDGE_RISING,
50 };
51
52 struct sunxi_sc_nmi_reg_offs {
53 u32 ctrl;
54 u32 pend;
55 u32 enable;
56 };
57
58 static const struct sunxi_sc_nmi_reg_offs sun6i_reg_offs __initconst = {
59 .ctrl = SUN6I_NMI_CTRL,
60 .pend = SUN6I_NMI_PENDING,
61 .enable = SUN6I_NMI_ENABLE,
62 };
63
64 static const struct sunxi_sc_nmi_reg_offs sun7i_reg_offs __initconst = {
65 .ctrl = SUN7I_NMI_CTRL,
66 .pend = SUN7I_NMI_PENDING,
67 .enable = SUN7I_NMI_ENABLE,
68 };
69
70 static const struct sunxi_sc_nmi_reg_offs sun9i_reg_offs __initconst = {
71 .ctrl = SUN9I_NMI_CTRL,
72 .pend = SUN9I_NMI_PENDING,
73 .enable = SUN9I_NMI_ENABLE,
74 };
75
sunxi_sc_nmi_write(struct irq_chip_generic * gc,u32 off,u32 val)76 static inline void sunxi_sc_nmi_write(struct irq_chip_generic *gc, u32 off,
77 u32 val)
78 {
79 irq_reg_writel(gc, val, off);
80 }
81
sunxi_sc_nmi_read(struct irq_chip_generic * gc,u32 off)82 static inline u32 sunxi_sc_nmi_read(struct irq_chip_generic *gc, u32 off)
83 {
84 return irq_reg_readl(gc, off);
85 }
86
sunxi_sc_nmi_handle_irq(struct irq_desc * desc)87 static void sunxi_sc_nmi_handle_irq(struct irq_desc *desc)
88 {
89 struct irq_domain *domain = irq_desc_get_handler_data(desc);
90 struct irq_chip *chip = irq_desc_get_chip(desc);
91
92 chained_irq_enter(chip, desc);
93 generic_handle_domain_irq(domain, 0);
94 chained_irq_exit(chip, desc);
95 }
96
sunxi_sc_nmi_set_type(struct irq_data * data,unsigned int flow_type)97 static int sunxi_sc_nmi_set_type(struct irq_data *data, unsigned int flow_type)
98 {
99 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
100 struct irq_chip_type *ct = gc->chip_types;
101 u32 src_type_reg;
102 u32 ctrl_off = ct->regs.type;
103 unsigned int src_type;
104 unsigned int i;
105
106 irq_gc_lock(gc);
107
108 switch (flow_type & IRQF_TRIGGER_MASK) {
109 case IRQ_TYPE_EDGE_FALLING:
110 src_type = SUNXI_SRC_TYPE_EDGE_FALLING;
111 break;
112 case IRQ_TYPE_EDGE_RISING:
113 src_type = SUNXI_SRC_TYPE_EDGE_RISING;
114 break;
115 case IRQ_TYPE_LEVEL_HIGH:
116 src_type = SUNXI_SRC_TYPE_LEVEL_HIGH;
117 break;
118 case IRQ_TYPE_NONE:
119 case IRQ_TYPE_LEVEL_LOW:
120 src_type = SUNXI_SRC_TYPE_LEVEL_LOW;
121 break;
122 default:
123 irq_gc_unlock(gc);
124 pr_err("Cannot assign multiple trigger modes to IRQ %d.\n",
125 data->irq);
126 return -EBADR;
127 }
128
129 irqd_set_trigger_type(data, flow_type);
130 irq_setup_alt_chip(data, flow_type);
131
132 for (i = 0; i < gc->num_ct; i++, ct++)
133 if (ct->type & flow_type)
134 ctrl_off = ct->regs.type;
135
136 src_type_reg = sunxi_sc_nmi_read(gc, ctrl_off);
137 src_type_reg &= ~SUNXI_NMI_SRC_TYPE_MASK;
138 src_type_reg |= src_type;
139 sunxi_sc_nmi_write(gc, ctrl_off, src_type_reg);
140
141 irq_gc_unlock(gc);
142
143 return IRQ_SET_MASK_OK;
144 }
145
sunxi_sc_nmi_irq_init(struct device_node * node,const struct sunxi_sc_nmi_reg_offs * reg_offs)146 static int __init sunxi_sc_nmi_irq_init(struct device_node *node,
147 const struct sunxi_sc_nmi_reg_offs *reg_offs)
148 {
149 struct irq_domain *domain;
150 struct irq_chip_generic *gc;
151 unsigned int irq;
152 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
153 int ret;
154
155
156 domain = irq_domain_add_linear(node, 1, &irq_generic_chip_ops, NULL);
157 if (!domain) {
158 pr_err("Could not register interrupt domain.\n");
159 return -ENOMEM;
160 }
161
162 ret = irq_alloc_domain_generic_chips(domain, 1, 2, DRV_NAME,
163 handle_fasteoi_irq, clr, 0,
164 IRQ_GC_INIT_MASK_CACHE);
165 if (ret) {
166 pr_err("Could not allocate generic interrupt chip.\n");
167 goto fail_irqd_remove;
168 }
169
170 irq = irq_of_parse_and_map(node, 0);
171 if (irq <= 0) {
172 pr_err("unable to parse irq\n");
173 ret = -EINVAL;
174 goto fail_irqd_remove;
175 }
176
177 gc = irq_get_domain_generic_chip(domain, 0);
178 gc->reg_base = of_io_request_and_map(node, 0, of_node_full_name(node));
179 if (IS_ERR(gc->reg_base)) {
180 pr_err("unable to map resource\n");
181 ret = PTR_ERR(gc->reg_base);
182 goto fail_irqd_remove;
183 }
184
185 gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
186 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
187 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
188 gc->chip_types[0].chip.irq_eoi = irq_gc_ack_set_bit;
189 gc->chip_types[0].chip.irq_set_type = sunxi_sc_nmi_set_type;
190 gc->chip_types[0].chip.flags = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED;
191 gc->chip_types[0].regs.ack = reg_offs->pend;
192 gc->chip_types[0].regs.mask = reg_offs->enable;
193 gc->chip_types[0].regs.type = reg_offs->ctrl;
194
195 gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
196 gc->chip_types[1].chip.name = gc->chip_types[0].chip.name;
197 gc->chip_types[1].chip.irq_ack = irq_gc_ack_set_bit;
198 gc->chip_types[1].chip.irq_mask = irq_gc_mask_clr_bit;
199 gc->chip_types[1].chip.irq_unmask = irq_gc_mask_set_bit;
200 gc->chip_types[1].chip.irq_set_type = sunxi_sc_nmi_set_type;
201 gc->chip_types[1].regs.ack = reg_offs->pend;
202 gc->chip_types[1].regs.mask = reg_offs->enable;
203 gc->chip_types[1].regs.type = reg_offs->ctrl;
204 gc->chip_types[1].handler = handle_edge_irq;
205
206 /* Disable any active interrupts */
207 sunxi_sc_nmi_write(gc, reg_offs->enable, 0);
208
209 /* Clear any pending NMI interrupts */
210 sunxi_sc_nmi_write(gc, reg_offs->pend, SUNXI_NMI_IRQ_BIT);
211
212 irq_set_chained_handler_and_data(irq, sunxi_sc_nmi_handle_irq, domain);
213
214 return 0;
215
216 fail_irqd_remove:
217 irq_domain_remove(domain);
218
219 return ret;
220 }
221
sun6i_sc_nmi_irq_init(struct device_node * node,struct device_node * parent)222 static int __init sun6i_sc_nmi_irq_init(struct device_node *node,
223 struct device_node *parent)
224 {
225 return sunxi_sc_nmi_irq_init(node, &sun6i_reg_offs);
226 }
227 IRQCHIP_DECLARE(sun6i_sc_nmi, "allwinner,sun6i-a31-sc-nmi", sun6i_sc_nmi_irq_init);
228
sun7i_sc_nmi_irq_init(struct device_node * node,struct device_node * parent)229 static int __init sun7i_sc_nmi_irq_init(struct device_node *node,
230 struct device_node *parent)
231 {
232 return sunxi_sc_nmi_irq_init(node, &sun7i_reg_offs);
233 }
234 IRQCHIP_DECLARE(sun7i_sc_nmi, "allwinner,sun7i-a20-sc-nmi", sun7i_sc_nmi_irq_init);
235
sun9i_nmi_irq_init(struct device_node * node,struct device_node * parent)236 static int __init sun9i_nmi_irq_init(struct device_node *node,
237 struct device_node *parent)
238 {
239 return sunxi_sc_nmi_irq_init(node, &sun9i_reg_offs);
240 }
241 IRQCHIP_DECLARE(sun9i_nmi, "allwinner,sun9i-a80-nmi", sun9i_nmi_irq_init);
242