1/*
  2 *  CLPS711X IRQ driver
  3 *
  4 *  Copyright (C) 2013 Alexander Shiyan <shc_work@mail.ru>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License as published by
  8 * the Free Software Foundation; either version 2 of the License, or
  9 * (at your option) any later version.
 10 */
 11
 12#include <linux/io.h>
 13#include <linux/irq.h>
 14#include <linux/irqdomain.h>
 15#include <linux/of_address.h>
 16#include <linux/of_irq.h>
 17#include <linux/slab.h>
 18
 19#include <asm/exception.h>
 20#include <asm/mach/irq.h>
 21
 22#include "irqchip.h"
 23
 24#define CLPS711X_INTSR1	(0x0240)
 25#define CLPS711X_INTMR1	(0x0280)
 26#define CLPS711X_BLEOI	(0x0600)
 27#define CLPS711X_MCEOI	(0x0640)
 28#define CLPS711X_TEOI	(0x0680)
 29#define CLPS711X_TC1EOI	(0x06c0)
 30#define CLPS711X_TC2EOI	(0x0700)
 31#define CLPS711X_RTCEOI	(0x0740)
 32#define CLPS711X_UMSEOI	(0x0780)
 33#define CLPS711X_COEOI	(0x07c0)
 34#define CLPS711X_INTSR2	(0x1240)
 35#define CLPS711X_INTMR2	(0x1280)
 36#define CLPS711X_SRXEOF	(0x1600)
 37#define CLPS711X_KBDEOI	(0x1700)
 38#define CLPS711X_INTSR3	(0x2240)
 39#define CLPS711X_INTMR3	(0x2280)
 40
 41static const struct {
 42#define CLPS711X_FLAG_EN	(1 << 0)
 43#define CLPS711X_FLAG_FIQ	(1 << 1)
 44	unsigned int	flags;
 45	phys_addr_t	eoi;
 46} clps711x_irqs[] = {
 47	[1]	= { CLPS711X_FLAG_FIQ, CLPS711X_BLEOI, },
 48	[3]	= { CLPS711X_FLAG_FIQ, CLPS711X_MCEOI, },
 49	[4]	= { CLPS711X_FLAG_EN, CLPS711X_COEOI, },
 50	[5]	= { CLPS711X_FLAG_EN, },
 51	[6]	= { CLPS711X_FLAG_EN, },
 52	[7]	= { CLPS711X_FLAG_EN, },
 53	[8]	= { CLPS711X_FLAG_EN, CLPS711X_TC1EOI, },
 54	[9]	= { CLPS711X_FLAG_EN, CLPS711X_TC2EOI, },
 55	[10]	= { CLPS711X_FLAG_EN, CLPS711X_RTCEOI, },
 56	[11]	= { CLPS711X_FLAG_EN, CLPS711X_TEOI, },
 57	[12]	= { CLPS711X_FLAG_EN, },
 58	[13]	= { CLPS711X_FLAG_EN, },
 59	[14]	= { CLPS711X_FLAG_EN, CLPS711X_UMSEOI, },
 60	[15]	= { CLPS711X_FLAG_EN, CLPS711X_SRXEOF, },
 61	[16]	= { CLPS711X_FLAG_EN, CLPS711X_KBDEOI, },
 62	[17]	= { CLPS711X_FLAG_EN, },
 63	[18]	= { CLPS711X_FLAG_EN, },
 64	[28]	= { CLPS711X_FLAG_EN, },
 65	[29]	= { CLPS711X_FLAG_EN, },
 66	[32]	= { CLPS711X_FLAG_FIQ, },
 67};
 68
 69static struct {
 70	void __iomem		*base;
 71	void __iomem		*intmr[3];
 72	void __iomem		*intsr[3];
 73	struct irq_domain	*domain;
 74	struct irq_domain_ops	ops;
 75} *clps711x_intc;
 76
 77static asmlinkage void __exception_irq_entry clps711x_irqh(struct pt_regs *regs)
 78{
 79	u32 irqnr, irqstat;
 80
 81	do {
 82		irqstat = readw_relaxed(clps711x_intc->intmr[0]) &
 83			  readw_relaxed(clps711x_intc->intsr[0]);
 84		if (irqstat) {
 85			irqnr =	irq_find_mapping(clps711x_intc->domain,
 86						 fls(irqstat) - 1);
 87			handle_IRQ(irqnr, regs);
 88		}
 89
 90		irqstat = readw_relaxed(clps711x_intc->intmr[1]) &
 91			  readw_relaxed(clps711x_intc->intsr[1]);
 92		if (irqstat) {
 93			irqnr =	irq_find_mapping(clps711x_intc->domain,
 94						 fls(irqstat) - 1 + 16);
 95			handle_IRQ(irqnr, regs);
 96		}
 97	} while (irqstat);
 98}
 99
100static void clps711x_intc_eoi(struct irq_data *d)
101{
102	irq_hw_number_t hwirq = irqd_to_hwirq(d);
103
104	writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hwirq].eoi);
105}
106
107static void clps711x_intc_mask(struct irq_data *d)
108{
109	irq_hw_number_t hwirq = irqd_to_hwirq(d);
110	void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
111	u32 tmp;
112
113	tmp = readl_relaxed(intmr);
114	tmp &= ~(1 << (hwirq % 16));
115	writel_relaxed(tmp, intmr);
116}
117
118static void clps711x_intc_unmask(struct irq_data *d)
119{
120	irq_hw_number_t hwirq = irqd_to_hwirq(d);
121	void __iomem *intmr = clps711x_intc->intmr[hwirq / 16];
122	u32 tmp;
123
124	tmp = readl_relaxed(intmr);
125	tmp |= 1 << (hwirq % 16);
126	writel_relaxed(tmp, intmr);
127}
128
129static struct irq_chip clps711x_intc_chip = {
130	.name		= "clps711x-intc",
131	.irq_eoi	= clps711x_intc_eoi,
132	.irq_mask	= clps711x_intc_mask,
133	.irq_unmask	= clps711x_intc_unmask,
134};
135
136static int __init clps711x_intc_irq_map(struct irq_domain *h, unsigned int virq,
137					irq_hw_number_t hw)
138{
139	irq_flow_handler_t handler = handle_level_irq;
140	unsigned int flags = IRQF_VALID | IRQF_PROBE;
141
142	if (!clps711x_irqs[hw].flags)
143		return 0;
144
145	if (clps711x_irqs[hw].flags & CLPS711X_FLAG_FIQ) {
146		handler = handle_bad_irq;
147		flags |= IRQF_NOAUTOEN;
148	} else if (clps711x_irqs[hw].eoi) {
149		handler = handle_fasteoi_irq;
150	}
151
152	/* Clear down pending interrupt */
153	if (clps711x_irqs[hw].eoi)
154		writel_relaxed(0, clps711x_intc->base + clps711x_irqs[hw].eoi);
155
156	irq_set_chip_and_handler(virq, &clps711x_intc_chip, handler);
157	set_irq_flags(virq, flags);
158
159	return 0;
160}
161
162static int __init _clps711x_intc_init(struct device_node *np,
163				      phys_addr_t base, resource_size_t size)
164{
165	int err;
166
167	clps711x_intc = kzalloc(sizeof(*clps711x_intc), GFP_KERNEL);
168	if (!clps711x_intc)
169		return -ENOMEM;
170
171	clps711x_intc->base = ioremap(base, size);
172	if (!clps711x_intc->base) {
173		err = -ENOMEM;
174		goto out_kfree;
175	}
176
177	clps711x_intc->intsr[0] = clps711x_intc->base + CLPS711X_INTSR1;
178	clps711x_intc->intmr[0] = clps711x_intc->base + CLPS711X_INTMR1;
179	clps711x_intc->intsr[1] = clps711x_intc->base + CLPS711X_INTSR2;
180	clps711x_intc->intmr[1] = clps711x_intc->base + CLPS711X_INTMR2;
181	clps711x_intc->intsr[2] = clps711x_intc->base + CLPS711X_INTSR3;
182	clps711x_intc->intmr[2] = clps711x_intc->base + CLPS711X_INTMR3;
183
184	/* Mask all interrupts */
185	writel_relaxed(0, clps711x_intc->intmr[0]);
186	writel_relaxed(0, clps711x_intc->intmr[1]);
187	writel_relaxed(0, clps711x_intc->intmr[2]);
188
189	err = irq_alloc_descs(-1, 0, ARRAY_SIZE(clps711x_irqs), numa_node_id());
190	if (IS_ERR_VALUE(err))
191		goto out_iounmap;
192
193	clps711x_intc->ops.map = clps711x_intc_irq_map;
194	clps711x_intc->ops.xlate = irq_domain_xlate_onecell;
195	clps711x_intc->domain =
196		irq_domain_add_legacy(np, ARRAY_SIZE(clps711x_irqs),
197				      0, 0, &clps711x_intc->ops, NULL);
198	if (!clps711x_intc->domain) {
199		err = -ENOMEM;
200		goto out_irqfree;
201	}
202
203	irq_set_default_host(clps711x_intc->domain);
204	set_handle_irq(clps711x_irqh);
205
206#ifdef CONFIG_FIQ
207	init_FIQ(0);
208#endif
209
210	return 0;
211
212out_irqfree:
213	irq_free_descs(0, ARRAY_SIZE(clps711x_irqs));
214
215out_iounmap:
216	iounmap(clps711x_intc->base);
217
218out_kfree:
219	kfree(clps711x_intc);
220
221	return err;
222}
223
224void __init clps711x_intc_init(phys_addr_t base, resource_size_t size)
225{
226	BUG_ON(_clps711x_intc_init(NULL, base, size));
227}
228
229#ifdef CONFIG_IRQCHIP
230static int __init clps711x_intc_init_dt(struct device_node *np,
231					struct device_node *parent)
232{
233	struct resource res;
234	int err;
235
236	err = of_address_to_resource(np, 0, &res);
237	if (err)
238		return err;
239
240	return _clps711x_intc_init(np, res.start, resource_size(&res));
241}
242IRQCHIP_DECLARE(clps711x, "cirrus,clps711x-intc", clps711x_intc_init_dt);
243#endif