xref: /openbmc/linux/drivers/irqchip/irq-mxs.c (revision edf8fcdc)
1 /*
2  * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
3  * Copyright (C) 2014 Oleksij Rempel <linux@rempel-privat.de>
4  *	Add Alphascale ASM9260 support.
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  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20 
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/irq.h>
24 #include <linux/irqchip.h>
25 #include <linux/irqdomain.h>
26 #include <linux/io.h>
27 #include <linux/of.h>
28 #include <linux/of_address.h>
29 #include <linux/of_irq.h>
30 #include <linux/stmp_device.h>
31 #include <asm/exception.h>
32 
33 #include "alphascale_asm9260-icoll.h"
34 
35 /*
36  * this device provide 4 offsets for each register:
37  * 0x0 - plain read write mode
38  * 0x4 - set mode, OR logic.
39  * 0x8 - clr mode, XOR logic.
40  * 0xc - togle mode.
41  */
42 #define SET_REG 4
43 #define CLR_REG 8
44 
45 #define HW_ICOLL_VECTOR				0x0000
46 #define HW_ICOLL_LEVELACK			0x0010
47 #define HW_ICOLL_CTRL				0x0020
48 #define HW_ICOLL_STAT_OFFSET			0x0070
49 #define HW_ICOLL_INTERRUPT0			0x0120
50 #define HW_ICOLL_INTERRUPTn(n)			((n) * 0x10)
51 #define BM_ICOLL_INTR_ENABLE			BIT(2)
52 #define BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0	0x1
53 
54 #define ICOLL_NUM_IRQS		128
55 
56 enum icoll_type {
57 	ICOLL,
58 	ASM9260_ICOLL,
59 };
60 
61 struct icoll_priv {
62 	void __iomem *vector;
63 	void __iomem *levelack;
64 	void __iomem *ctrl;
65 	void __iomem *stat;
66 	void __iomem *intr;
67 	void __iomem *clear;
68 	enum icoll_type type;
69 };
70 
71 static struct icoll_priv icoll_priv;
72 static struct irq_domain *icoll_domain;
73 
74 /* calculate bit offset depending on number of intterupt per register */
75 static u32 icoll_intr_bitshift(struct irq_data *d, u32 bit)
76 {
77 	/*
78 	 * mask lower part of hwirq to convert it
79 	 * in 0, 1, 2 or 3 and then multiply it by 8 (or shift by 3)
80 	 */
81 	return bit << ((d->hwirq & 3) << 3);
82 }
83 
84 /* calculate mem offset depending on number of intterupt per register */
85 static void __iomem *icoll_intr_reg(struct irq_data *d)
86 {
87 	/* offset = hwirq / intr_per_reg * 0x10 */
88 	return icoll_priv.intr + ((d->hwirq >> 2) * 0x10);
89 }
90 
91 static void icoll_ack_irq(struct irq_data *d)
92 {
93 	/*
94 	 * The Interrupt Collector is able to prioritize irqs.
95 	 * Currently only level 0 is used. So acking can use
96 	 * BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0 unconditionally.
97 	 */
98 	__raw_writel(BV_ICOLL_LEVELACK_IRQLEVELACK__LEVEL0,
99 			icoll_priv.levelack);
100 }
101 
102 static void icoll_mask_irq(struct irq_data *d)
103 {
104 	__raw_writel(BM_ICOLL_INTR_ENABLE,
105 			icoll_priv.intr + CLR_REG + HW_ICOLL_INTERRUPTn(d->hwirq));
106 }
107 
108 static void icoll_unmask_irq(struct irq_data *d)
109 {
110 	__raw_writel(BM_ICOLL_INTR_ENABLE,
111 			icoll_priv.intr + SET_REG + HW_ICOLL_INTERRUPTn(d->hwirq));
112 }
113 
114 static void asm9260_mask_irq(struct irq_data *d)
115 {
116 	__raw_writel(icoll_intr_bitshift(d, BM_ICOLL_INTR_ENABLE),
117 			icoll_intr_reg(d) + CLR_REG);
118 }
119 
120 static void asm9260_unmask_irq(struct irq_data *d)
121 {
122 	__raw_writel(ASM9260_BM_CLEAR_BIT(d->hwirq),
123 		     icoll_priv.clear +
124 		     ASM9260_HW_ICOLL_CLEARn(d->hwirq));
125 
126 	__raw_writel(icoll_intr_bitshift(d, BM_ICOLL_INTR_ENABLE),
127 			icoll_intr_reg(d) + SET_REG);
128 }
129 
130 static struct irq_chip mxs_icoll_chip = {
131 	.irq_ack = icoll_ack_irq,
132 	.irq_mask = icoll_mask_irq,
133 	.irq_unmask = icoll_unmask_irq,
134 };
135 
136 static struct irq_chip asm9260_icoll_chip = {
137 	.irq_ack = icoll_ack_irq,
138 	.irq_mask = asm9260_mask_irq,
139 	.irq_unmask = asm9260_unmask_irq,
140 };
141 
142 asmlinkage void __exception_irq_entry icoll_handle_irq(struct pt_regs *regs)
143 {
144 	u32 irqnr;
145 
146 	irqnr = __raw_readl(icoll_priv.stat);
147 	__raw_writel(irqnr, icoll_priv.vector);
148 	handle_domain_irq(icoll_domain, irqnr, regs);
149 }
150 
151 static int icoll_irq_domain_map(struct irq_domain *d, unsigned int virq,
152 				irq_hw_number_t hw)
153 {
154 	struct irq_chip *chip;
155 
156 	if (icoll_priv.type == ICOLL)
157 		chip = &mxs_icoll_chip;
158 	else
159 		chip = &asm9260_icoll_chip;
160 
161 	irq_set_chip_and_handler(virq, chip, handle_level_irq);
162 
163 	return 0;
164 }
165 
166 static const struct irq_domain_ops icoll_irq_domain_ops = {
167 	.map = icoll_irq_domain_map,
168 	.xlate = irq_domain_xlate_onecell,
169 };
170 
171 static void __init icoll_add_domain(struct device_node *np,
172 			  int num)
173 {
174 	icoll_domain = irq_domain_add_linear(np, num,
175 					     &icoll_irq_domain_ops, NULL);
176 
177 	if (!icoll_domain)
178 		panic("%s: unable to create irq domain", np->full_name);
179 }
180 
181 static void __iomem * __init icoll_init_iobase(struct device_node *np)
182 {
183 	void __iomem *icoll_base;
184 
185 	icoll_base = of_io_request_and_map(np, 0, np->name);
186 	if (IS_ERR(icoll_base))
187 		panic("%s: unable to map resource", np->full_name);
188 	return icoll_base;
189 }
190 
191 static int __init icoll_of_init(struct device_node *np,
192 			  struct device_node *interrupt_parent)
193 {
194 	void __iomem *icoll_base;
195 
196 	icoll_priv.type = ICOLL;
197 
198 	icoll_base		= icoll_init_iobase(np);
199 	icoll_priv.vector	= icoll_base + HW_ICOLL_VECTOR;
200 	icoll_priv.levelack	= icoll_base + HW_ICOLL_LEVELACK;
201 	icoll_priv.ctrl		= icoll_base + HW_ICOLL_CTRL;
202 	icoll_priv.stat		= icoll_base + HW_ICOLL_STAT_OFFSET;
203 	icoll_priv.intr		= icoll_base + HW_ICOLL_INTERRUPT0;
204 	icoll_priv.clear	= NULL;
205 
206 	/*
207 	 * Interrupt Collector reset, which initializes the priority
208 	 * for each irq to level 0.
209 	 */
210 	stmp_reset_block(icoll_priv.ctrl);
211 
212 	icoll_add_domain(np, ICOLL_NUM_IRQS);
213 
214 	return 0;
215 }
216 IRQCHIP_DECLARE(mxs, "fsl,icoll", icoll_of_init);
217 
218 static int __init asm9260_of_init(struct device_node *np,
219 			  struct device_node *interrupt_parent)
220 {
221 	void __iomem *icoll_base;
222 	int i;
223 
224 	icoll_priv.type = ASM9260_ICOLL;
225 
226 	icoll_base = icoll_init_iobase(np);
227 	icoll_priv.vector	= icoll_base + ASM9260_HW_ICOLL_VECTOR;
228 	icoll_priv.levelack	= icoll_base + ASM9260_HW_ICOLL_LEVELACK;
229 	icoll_priv.ctrl		= icoll_base + ASM9260_HW_ICOLL_CTRL;
230 	icoll_priv.stat		= icoll_base + ASM9260_HW_ICOLL_STAT_OFFSET;
231 	icoll_priv.intr		= icoll_base + ASM9260_HW_ICOLL_INTERRUPT0;
232 	icoll_priv.clear	= icoll_base + ASM9260_HW_ICOLL_CLEAR0;
233 
234 	writel_relaxed(ASM9260_BM_CTRL_IRQ_ENABLE,
235 			icoll_priv.ctrl);
236 	/*
237 	 * ASM9260 don't provide reset bit. So, we need to set level 0
238 	 * manually.
239 	 */
240 	for (i = 0; i < 16 * 0x10; i += 0x10)
241 		writel(0, icoll_priv.intr + i);
242 
243 	icoll_add_domain(np, ASM9260_NUM_IRQS);
244 	set_handle_irq(icoll_handle_irq);
245 
246 	return 0;
247 }
248 IRQCHIP_DECLARE(asm9260, "alphascale,asm9260-icoll", asm9260_of_init);
249