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 #define SUN6I_R_INTC_CTRL 0x0c
31 #define SUN6I_R_INTC_PENDING 0x10
32 #define SUN6I_R_INTC_ENABLE 0x40
33
34 /*
35 * For deprecated sun6i-a31-sc-nmi compatible.
36 * Registers are offset by 0x0c.
37 */
38 #define SUN6I_R_INTC_NMI_OFFSET 0x0c
39 #define SUN6I_NMI_CTRL (SUN6I_R_INTC_CTRL - SUN6I_R_INTC_NMI_OFFSET)
40 #define SUN6I_NMI_PENDING (SUN6I_R_INTC_PENDING - SUN6I_R_INTC_NMI_OFFSET)
41 #define SUN6I_NMI_ENABLE (SUN6I_R_INTC_ENABLE - SUN6I_R_INTC_NMI_OFFSET)
42
43 #define SUN7I_NMI_CTRL 0x00
44 #define SUN7I_NMI_PENDING 0x04
45 #define SUN7I_NMI_ENABLE 0x08
46
47 #define SUN9I_NMI_CTRL 0x00
48 #define SUN9I_NMI_ENABLE 0x04
49 #define SUN9I_NMI_PENDING 0x08
50
51 enum {
52 SUNXI_SRC_TYPE_LEVEL_LOW = 0,
53 SUNXI_SRC_TYPE_EDGE_FALLING,
54 SUNXI_SRC_TYPE_LEVEL_HIGH,
55 SUNXI_SRC_TYPE_EDGE_RISING,
56 };
57
58 struct sunxi_sc_nmi_reg_offs {
59 u32 ctrl;
60 u32 pend;
61 u32 enable;
62 };
63
64 static const struct sunxi_sc_nmi_reg_offs sun6i_r_intc_reg_offs __initconst = {
65 .ctrl = SUN6I_R_INTC_CTRL,
66 .pend = SUN6I_R_INTC_PENDING,
67 .enable = SUN6I_R_INTC_ENABLE,
68 };
69
70 static const struct sunxi_sc_nmi_reg_offs sun6i_reg_offs __initconst = {
71 .ctrl = SUN6I_NMI_CTRL,
72 .pend = SUN6I_NMI_PENDING,
73 .enable = SUN6I_NMI_ENABLE,
74 };
75
76 static const struct sunxi_sc_nmi_reg_offs sun7i_reg_offs __initconst = {
77 .ctrl = SUN7I_NMI_CTRL,
78 .pend = SUN7I_NMI_PENDING,
79 .enable = SUN7I_NMI_ENABLE,
80 };
81
82 static const struct sunxi_sc_nmi_reg_offs sun9i_reg_offs __initconst = {
83 .ctrl = SUN9I_NMI_CTRL,
84 .pend = SUN9I_NMI_PENDING,
85 .enable = SUN9I_NMI_ENABLE,
86 };
87
sunxi_sc_nmi_write(struct irq_chip_generic * gc,u32 off,u32 val)88 static inline void sunxi_sc_nmi_write(struct irq_chip_generic *gc, u32 off,
89 u32 val)
90 {
91 irq_reg_writel(gc, val, off);
92 }
93
sunxi_sc_nmi_read(struct irq_chip_generic * gc,u32 off)94 static inline u32 sunxi_sc_nmi_read(struct irq_chip_generic *gc, u32 off)
95 {
96 return irq_reg_readl(gc, off);
97 }
98
sunxi_sc_nmi_handle_irq(struct irq_desc * desc)99 static void sunxi_sc_nmi_handle_irq(struct irq_desc *desc)
100 {
101 struct irq_domain *domain = irq_desc_get_handler_data(desc);
102 struct irq_chip *chip = irq_desc_get_chip(desc);
103 unsigned int virq = irq_find_mapping(domain, 0);
104
105 chained_irq_enter(chip, desc);
106 generic_handle_irq(virq);
107 chained_irq_exit(chip, desc);
108 }
109
sunxi_sc_nmi_set_type(struct irq_data * data,unsigned int flow_type)110 static int sunxi_sc_nmi_set_type(struct irq_data *data, unsigned int flow_type)
111 {
112 struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
113 struct irq_chip_type *ct = gc->chip_types;
114 u32 src_type_reg;
115 u32 ctrl_off = ct->regs.type;
116 unsigned int src_type;
117 unsigned int i;
118
119 irq_gc_lock(gc);
120
121 switch (flow_type & IRQF_TRIGGER_MASK) {
122 case IRQ_TYPE_EDGE_FALLING:
123 src_type = SUNXI_SRC_TYPE_EDGE_FALLING;
124 break;
125 case IRQ_TYPE_EDGE_RISING:
126 src_type = SUNXI_SRC_TYPE_EDGE_RISING;
127 break;
128 case IRQ_TYPE_LEVEL_HIGH:
129 src_type = SUNXI_SRC_TYPE_LEVEL_HIGH;
130 break;
131 case IRQ_TYPE_NONE:
132 case IRQ_TYPE_LEVEL_LOW:
133 src_type = SUNXI_SRC_TYPE_LEVEL_LOW;
134 break;
135 default:
136 irq_gc_unlock(gc);
137 pr_err("Cannot assign multiple trigger modes to IRQ %d.\n",
138 data->irq);
139 return -EBADR;
140 }
141
142 irqd_set_trigger_type(data, flow_type);
143 irq_setup_alt_chip(data, flow_type);
144
145 for (i = 0; i < gc->num_ct; i++, ct++)
146 if (ct->type & flow_type)
147 ctrl_off = ct->regs.type;
148
149 src_type_reg = sunxi_sc_nmi_read(gc, ctrl_off);
150 src_type_reg &= ~SUNXI_NMI_SRC_TYPE_MASK;
151 src_type_reg |= src_type;
152 sunxi_sc_nmi_write(gc, ctrl_off, src_type_reg);
153
154 irq_gc_unlock(gc);
155
156 return IRQ_SET_MASK_OK;
157 }
158
sunxi_sc_nmi_irq_init(struct device_node * node,const struct sunxi_sc_nmi_reg_offs * reg_offs)159 static int __init sunxi_sc_nmi_irq_init(struct device_node *node,
160 const struct sunxi_sc_nmi_reg_offs *reg_offs)
161 {
162 struct irq_domain *domain;
163 struct irq_chip_generic *gc;
164 unsigned int irq;
165 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
166 int ret;
167
168
169 domain = irq_domain_add_linear(node, 1, &irq_generic_chip_ops, NULL);
170 if (!domain) {
171 pr_err("Could not register interrupt domain.\n");
172 return -ENOMEM;
173 }
174
175 ret = irq_alloc_domain_generic_chips(domain, 1, 2, DRV_NAME,
176 handle_fasteoi_irq, clr, 0,
177 IRQ_GC_INIT_MASK_CACHE);
178 if (ret) {
179 pr_err("Could not allocate generic interrupt chip.\n");
180 goto fail_irqd_remove;
181 }
182
183 irq = irq_of_parse_and_map(node, 0);
184 if (irq <= 0) {
185 pr_err("unable to parse irq\n");
186 ret = -EINVAL;
187 goto fail_irqd_remove;
188 }
189
190 gc = irq_get_domain_generic_chip(domain, 0);
191 gc->reg_base = of_io_request_and_map(node, 0, of_node_full_name(node));
192 if (IS_ERR(gc->reg_base)) {
193 pr_err("unable to map resource\n");
194 ret = PTR_ERR(gc->reg_base);
195 goto fail_irqd_remove;
196 }
197
198 gc->chip_types[0].type = IRQ_TYPE_LEVEL_MASK;
199 gc->chip_types[0].chip.irq_mask = irq_gc_mask_clr_bit;
200 gc->chip_types[0].chip.irq_unmask = irq_gc_mask_set_bit;
201 gc->chip_types[0].chip.irq_eoi = irq_gc_ack_set_bit;
202 gc->chip_types[0].chip.irq_set_type = sunxi_sc_nmi_set_type;
203 gc->chip_types[0].chip.flags = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED;
204 gc->chip_types[0].regs.ack = reg_offs->pend;
205 gc->chip_types[0].regs.mask = reg_offs->enable;
206 gc->chip_types[0].regs.type = reg_offs->ctrl;
207
208 gc->chip_types[1].type = IRQ_TYPE_EDGE_BOTH;
209 gc->chip_types[1].chip.name = gc->chip_types[0].chip.name;
210 gc->chip_types[1].chip.irq_ack = irq_gc_ack_set_bit;
211 gc->chip_types[1].chip.irq_mask = irq_gc_mask_clr_bit;
212 gc->chip_types[1].chip.irq_unmask = irq_gc_mask_set_bit;
213 gc->chip_types[1].chip.irq_set_type = sunxi_sc_nmi_set_type;
214 gc->chip_types[1].regs.ack = reg_offs->pend;
215 gc->chip_types[1].regs.mask = reg_offs->enable;
216 gc->chip_types[1].regs.type = reg_offs->ctrl;
217 gc->chip_types[1].handler = handle_edge_irq;
218
219 /* Disable any active interrupts */
220 sunxi_sc_nmi_write(gc, reg_offs->enable, 0);
221
222 /* Clear any pending NMI interrupts */
223 sunxi_sc_nmi_write(gc, reg_offs->pend, SUNXI_NMI_IRQ_BIT);
224
225 irq_set_chained_handler_and_data(irq, sunxi_sc_nmi_handle_irq, domain);
226
227 return 0;
228
229 fail_irqd_remove:
230 irq_domain_remove(domain);
231
232 return ret;
233 }
234
sun6i_r_intc_irq_init(struct device_node * node,struct device_node * parent)235 static int __init sun6i_r_intc_irq_init(struct device_node *node,
236 struct device_node *parent)
237 {
238 return sunxi_sc_nmi_irq_init(node, &sun6i_r_intc_reg_offs);
239 }
240 IRQCHIP_DECLARE(sun6i_r_intc, "allwinner,sun6i-a31-r-intc",
241 sun6i_r_intc_irq_init);
242
sun6i_sc_nmi_irq_init(struct device_node * node,struct device_node * parent)243 static int __init sun6i_sc_nmi_irq_init(struct device_node *node,
244 struct device_node *parent)
245 {
246 return sunxi_sc_nmi_irq_init(node, &sun6i_reg_offs);
247 }
248 IRQCHIP_DECLARE(sun6i_sc_nmi, "allwinner,sun6i-a31-sc-nmi", sun6i_sc_nmi_irq_init);
249
sun7i_sc_nmi_irq_init(struct device_node * node,struct device_node * parent)250 static int __init sun7i_sc_nmi_irq_init(struct device_node *node,
251 struct device_node *parent)
252 {
253 return sunxi_sc_nmi_irq_init(node, &sun7i_reg_offs);
254 }
255 IRQCHIP_DECLARE(sun7i_sc_nmi, "allwinner,sun7i-a20-sc-nmi", sun7i_sc_nmi_irq_init);
256
sun9i_nmi_irq_init(struct device_node * node,struct device_node * parent)257 static int __init sun9i_nmi_irq_init(struct device_node *node,
258 struct device_node *parent)
259 {
260 return sunxi_sc_nmi_irq_init(node, &sun9i_reg_offs);
261 }
262 IRQCHIP_DECLARE(sun9i_nmi, "allwinner,sun9i-a80-nmi", sun9i_nmi_irq_init);
263