1 /*
2 * Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2012-2013 Xilinx, Inc.
4 * Copyright (C) 2007-2009 PetaLogix
5 * Copyright (C) 2006 Atmark Techno, Inc.
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License. See the file "COPYING" in the main directory of this archive
9 * for more details.
10 */
11
12 #include <linux/irqdomain.h>
13 #include <linux/irq.h>
14 #include <linux/irqchip.h>
15 #include <linux/irqchip/chained_irq.h>
16 #include <linux/of_address.h>
17 #include <linux/io.h>
18 #include <linux/jump_label.h>
19 #include <linux/bug.h>
20 #include <linux/of_irq.h>
21
22 /* No one else should require these constants, so define them locally here. */
23 #define ISR 0x00 /* Interrupt Status Register */
24 #define IPR 0x04 /* Interrupt Pending Register */
25 #define IER 0x08 /* Interrupt Enable Register */
26 #define IAR 0x0c /* Interrupt Acknowledge Register */
27 #define SIE 0x10 /* Set Interrupt Enable bits */
28 #define CIE 0x14 /* Clear Interrupt Enable bits */
29 #define IVR 0x18 /* Interrupt Vector Register */
30 #define MER 0x1c /* Master Enable Register */
31
32 #define MER_ME (1<<0)
33 #define MER_HIE (1<<1)
34
35 static DEFINE_STATIC_KEY_FALSE(xintc_is_be);
36
37 struct xintc_irq_chip {
38 void __iomem *base;
39 struct irq_domain *root_domain;
40 u32 intr_mask;
41 };
42
43 static struct xintc_irq_chip *xintc_irqc;
44
xintc_write(int reg,u32 data)45 static void xintc_write(int reg, u32 data)
46 {
47 if (static_branch_unlikely(&xintc_is_be))
48 iowrite32be(data, xintc_irqc->base + reg);
49 else
50 iowrite32(data, xintc_irqc->base + reg);
51 }
52
xintc_read(int reg)53 static unsigned int xintc_read(int reg)
54 {
55 if (static_branch_unlikely(&xintc_is_be))
56 return ioread32be(xintc_irqc->base + reg);
57 else
58 return ioread32(xintc_irqc->base + reg);
59 }
60
intc_enable_or_unmask(struct irq_data * d)61 static void intc_enable_or_unmask(struct irq_data *d)
62 {
63 unsigned long mask = 1 << d->hwirq;
64
65 pr_debug("irq-xilinx: enable_or_unmask: %ld\n", d->hwirq);
66
67 /* ack level irqs because they can't be acked during
68 * ack function since the handle_level_irq function
69 * acks the irq before calling the interrupt handler
70 */
71 if (irqd_is_level_type(d))
72 xintc_write(IAR, mask);
73
74 xintc_write(SIE, mask);
75 }
76
intc_disable_or_mask(struct irq_data * d)77 static void intc_disable_or_mask(struct irq_data *d)
78 {
79 pr_debug("irq-xilinx: disable: %ld\n", d->hwirq);
80 xintc_write(CIE, 1 << d->hwirq);
81 }
82
intc_ack(struct irq_data * d)83 static void intc_ack(struct irq_data *d)
84 {
85 pr_debug("irq-xilinx: ack: %ld\n", d->hwirq);
86 xintc_write(IAR, 1 << d->hwirq);
87 }
88
intc_mask_ack(struct irq_data * d)89 static void intc_mask_ack(struct irq_data *d)
90 {
91 unsigned long mask = 1 << d->hwirq;
92
93 pr_debug("irq-xilinx: disable_and_ack: %ld\n", d->hwirq);
94 xintc_write(CIE, mask);
95 xintc_write(IAR, mask);
96 }
97
98 static struct irq_chip intc_dev = {
99 .name = "Xilinx INTC",
100 .irq_unmask = intc_enable_or_unmask,
101 .irq_mask = intc_disable_or_mask,
102 .irq_ack = intc_ack,
103 .irq_mask_ack = intc_mask_ack,
104 };
105
xintc_get_irq(void)106 unsigned int xintc_get_irq(void)
107 {
108 unsigned int hwirq, irq = -1;
109
110 hwirq = xintc_read(IVR);
111 if (hwirq != -1U)
112 irq = irq_find_mapping(xintc_irqc->root_domain, hwirq);
113
114 pr_debug("irq-xilinx: hwirq=%d, irq=%d\n", hwirq, irq);
115
116 return irq;
117 }
118
xintc_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hw)119 static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
120 {
121 if (xintc_irqc->intr_mask & (1 << hw)) {
122 irq_set_chip_and_handler_name(irq, &intc_dev,
123 handle_edge_irq, "edge");
124 irq_clear_status_flags(irq, IRQ_LEVEL);
125 } else {
126 irq_set_chip_and_handler_name(irq, &intc_dev,
127 handle_level_irq, "level");
128 irq_set_status_flags(irq, IRQ_LEVEL);
129 }
130 return 0;
131 }
132
133 static const struct irq_domain_ops xintc_irq_domain_ops = {
134 .xlate = irq_domain_xlate_onetwocell,
135 .map = xintc_map,
136 };
137
xil_intc_irq_handler(struct irq_desc * desc)138 static void xil_intc_irq_handler(struct irq_desc *desc)
139 {
140 struct irq_chip *chip = irq_desc_get_chip(desc);
141 u32 pending;
142
143 chained_irq_enter(chip, desc);
144 do {
145 pending = xintc_get_irq();
146 if (pending == -1U)
147 break;
148 generic_handle_irq(pending);
149 } while (true);
150 chained_irq_exit(chip, desc);
151 }
152
xilinx_intc_of_init(struct device_node * intc,struct device_node * parent)153 static int __init xilinx_intc_of_init(struct device_node *intc,
154 struct device_node *parent)
155 {
156 u32 nr_irq;
157 int ret, irq;
158 struct xintc_irq_chip *irqc;
159
160 if (xintc_irqc) {
161 pr_err("irq-xilinx: Multiple instances aren't supported\n");
162 return -EINVAL;
163 }
164
165 irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
166 if (!irqc)
167 return -ENOMEM;
168
169 xintc_irqc = irqc;
170
171 irqc->base = of_iomap(intc, 0);
172 BUG_ON(!irqc->base);
173
174 ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &nr_irq);
175 if (ret < 0) {
176 pr_err("irq-xilinx: unable to read xlnx,num-intr-inputs\n");
177 goto err_alloc;
178 }
179
180 ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask);
181 if (ret < 0) {
182 pr_warn("irq-xilinx: unable to read xlnx,kind-of-intr\n");
183 irqc->intr_mask = 0;
184 }
185
186 if (irqc->intr_mask >> nr_irq)
187 pr_warn("irq-xilinx: mismatch in kind-of-intr param\n");
188
189 pr_info("irq-xilinx: %pOF: num_irq=%d, edge=0x%x\n",
190 intc, nr_irq, irqc->intr_mask);
191
192
193 /*
194 * Disable all external interrupts until they are
195 * explicity requested.
196 */
197 xintc_write(IER, 0);
198
199 /* Acknowledge any pending interrupts just in case. */
200 xintc_write(IAR, 0xffffffff);
201
202 /* Turn on the Master Enable. */
203 xintc_write(MER, MER_HIE | MER_ME);
204 if (!(xintc_read(MER) & (MER_HIE | MER_ME))) {
205 static_branch_enable(&xintc_is_be);
206 xintc_write(MER, MER_HIE | MER_ME);
207 }
208
209 irqc->root_domain = irq_domain_add_linear(intc, nr_irq,
210 &xintc_irq_domain_ops, irqc);
211 if (!irqc->root_domain) {
212 pr_err("irq-xilinx: Unable to create IRQ domain\n");
213 goto err_alloc;
214 }
215
216 if (parent) {
217 irq = irq_of_parse_and_map(intc, 0);
218 if (irq) {
219 irq_set_chained_handler_and_data(irq,
220 xil_intc_irq_handler,
221 irqc);
222 } else {
223 pr_err("irq-xilinx: interrupts property not in DT\n");
224 ret = -EINVAL;
225 goto err_alloc;
226 }
227 } else {
228 irq_set_default_host(irqc->root_domain);
229 }
230
231 return 0;
232
233 err_alloc:
234 xintc_irqc = NULL;
235 kfree(irqc);
236 return ret;
237
238 }
239
240 IRQCHIP_DECLARE(xilinx_intc_xps, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);
241 IRQCHIP_DECLARE(xilinx_intc_opb, "xlnx,opb-intc-1.00.c", xilinx_intc_of_init);
242