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1/*
2 * arch/sh/boards/mach-x3proto/ilsel.c
3 *
4 * Helper routines for SH-X3 proto board ILSEL.
5 *
6 * Copyright (C) 2007 - 2010 Paul Mundt
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
10 * for more details.
11 */
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/bitmap.h>
18#include <linux/io.h>
19#include <mach/ilsel.h>
20
21/*
22 * ILSEL is split across:
23 *
24 * ILSEL0 - 0xb8100004 [ Levels 1 - 4 ]
25 * ILSEL1 - 0xb8100006 [ Levels 5 - 8 ]
26 * ILSEL2 - 0xb8100008 [ Levels 9 - 12 ]
27 * ILSEL3 - 0xb810000a [ Levels 13 - 15 ]
28 *
29 * With each level being relative to an ilsel_source_t.
30 */
31#define ILSEL_BASE 0xb8100004
32#define ILSEL_LEVELS 15
33
34/*
35 * ILSEL level map, in descending order from the highest level down.
36 *
37 * Supported levels are 1 - 15 spread across ILSEL0 - ILSEL4, mapping
38 * directly to IRLs. As the IRQs are numbered in reverse order relative
39 * to the interrupt level, the level map is carefully managed to ensure a
40 * 1:1 mapping between the bit position and the IRQ number.
41 *
42 * This careful constructions allows ilsel_enable*() to be referenced
43 * directly for hooking up an ILSEL set and getting back an IRQ which can
44 * subsequently be used for internal accounting in the (optional) disable
45 * path.
46 */
47static unsigned long ilsel_level_map;
48
49static inline unsigned int ilsel_offset(unsigned int bit)
50{
51 return ILSEL_LEVELS - bit - 1;
52}
53
54static inline unsigned long mk_ilsel_addr(unsigned int bit)
55{
56 return ILSEL_BASE + ((ilsel_offset(bit) >> 1) & ~0x1);
57}
58
59static inline unsigned int mk_ilsel_shift(unsigned int bit)
60{
61 return (ilsel_offset(bit) & 0x3) << 2;
62}
63
64static void __ilsel_enable(ilsel_source_t set, unsigned int bit)
65{
66 unsigned int tmp, shift;
67 unsigned long addr;
68
69 pr_notice("enabling ILSEL set %d\n", set);
70
71 addr = mk_ilsel_addr(bit);
72 shift = mk_ilsel_shift(bit);
73
74 pr_debug("%s: bit#%d: addr - 0x%08lx (shift %d, set %d)\n",
75 __func__, bit, addr, shift, set);
76
77 tmp = __raw_readw(addr);
78 tmp &= ~(0xf << shift);
79 tmp |= set << shift;
80 __raw_writew(tmp, addr);
81}
82
83/**
84 * ilsel_enable - Enable an ILSEL set.
85 * @set: ILSEL source (see ilsel_source_t enum in include/asm-sh/ilsel.h).
86 *
87 * Enables a given non-aliased ILSEL source (<= ILSEL_KEY) at the highest
88 * available interrupt level. Callers should take care to order callsites
89 * noting descending interrupt levels. Aliasing FPGA and external board
90 * IRQs need to use ilsel_enable_fixed().
91 *
92 * The return value is an IRQ number that can later be taken down with
93 * ilsel_disable().
94 */
95int ilsel_enable(ilsel_source_t set)
96{
97 unsigned int bit;
98
99 if (unlikely(set > ILSEL_KEY)) {
100 pr_err("Aliased sources must use ilsel_enable_fixed()\n");
101 return -EINVAL;
102 }
103
104 do {
105 bit = find_first_zero_bit(&ilsel_level_map, ILSEL_LEVELS);
106 } while (test_and_set_bit(bit, &ilsel_level_map));
107
108 __ilsel_enable(set, bit);
109
110 return bit;
111}
112EXPORT_SYMBOL_GPL(ilsel_enable);
113
114/**
115 * ilsel_enable_fixed - Enable an ILSEL set at a fixed interrupt level
116 * @set: ILSEL source (see ilsel_source_t enum in include/asm-sh/ilsel.h).
117 * @level: Interrupt level (1 - 15)
118 *
119 * Enables a given ILSEL source at a fixed interrupt level. Necessary
120 * both for level reservation as well as for aliased sources that only
121 * exist on special ILSEL#s.
122 *
123 * Returns an IRQ number (as ilsel_enable()).
124 */
125int ilsel_enable_fixed(ilsel_source_t set, unsigned int level)
126{
127 unsigned int bit = ilsel_offset(level - 1);
128
129 if (test_and_set_bit(bit, &ilsel_level_map))
130 return -EBUSY;
131
132 __ilsel_enable(set, bit);
133
134 return bit;
135}
136EXPORT_SYMBOL_GPL(ilsel_enable_fixed);
137
138/**
139 * ilsel_disable - Disable an ILSEL set
140 * @irq: Bit position for ILSEL set value (retval from enable routines)
141 *
142 * Disable a previously enabled ILSEL set.
143 */
144void ilsel_disable(unsigned int irq)
145{
146 unsigned long addr;
147 unsigned int tmp;
148
149 pr_notice("disabling ILSEL set %d\n", irq);
150
151 addr = mk_ilsel_addr(irq);
152
153 tmp = __raw_readw(addr);
154 tmp &= ~(0xf << mk_ilsel_shift(irq));
155 __raw_writew(tmp, addr);
156
157 clear_bit(irq, &ilsel_level_map);
158}
159EXPORT_SYMBOL_GPL(ilsel_disable);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sh/boards/mach-x3proto/ilsel.c
4 *
5 * Helper routines for SH-X3 proto board ILSEL.
6 *
7 * Copyright (C) 2007 - 2010 Paul Mundt
8 */
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/bitmap.h>
15#include <linux/io.h>
16#include <mach/ilsel.h>
17
18/*
19 * ILSEL is split across:
20 *
21 * ILSEL0 - 0xb8100004 [ Levels 1 - 4 ]
22 * ILSEL1 - 0xb8100006 [ Levels 5 - 8 ]
23 * ILSEL2 - 0xb8100008 [ Levels 9 - 12 ]
24 * ILSEL3 - 0xb810000a [ Levels 13 - 15 ]
25 *
26 * With each level being relative to an ilsel_source_t.
27 */
28#define ILSEL_BASE 0xb8100004
29#define ILSEL_LEVELS 15
30
31/*
32 * ILSEL level map, in descending order from the highest level down.
33 *
34 * Supported levels are 1 - 15 spread across ILSEL0 - ILSEL4, mapping
35 * directly to IRLs. As the IRQs are numbered in reverse order relative
36 * to the interrupt level, the level map is carefully managed to ensure a
37 * 1:1 mapping between the bit position and the IRQ number.
38 *
39 * This careful constructions allows ilsel_enable*() to be referenced
40 * directly for hooking up an ILSEL set and getting back an IRQ which can
41 * subsequently be used for internal accounting in the (optional) disable
42 * path.
43 */
44static unsigned long ilsel_level_map;
45
46static inline unsigned int ilsel_offset(unsigned int bit)
47{
48 return ILSEL_LEVELS - bit - 1;
49}
50
51static inline unsigned long mk_ilsel_addr(unsigned int bit)
52{
53 return ILSEL_BASE + ((ilsel_offset(bit) >> 1) & ~0x1);
54}
55
56static inline unsigned int mk_ilsel_shift(unsigned int bit)
57{
58 return (ilsel_offset(bit) & 0x3) << 2;
59}
60
61static void __ilsel_enable(ilsel_source_t set, unsigned int bit)
62{
63 unsigned int tmp, shift;
64 unsigned long addr;
65
66 pr_notice("enabling ILSEL set %d\n", set);
67
68 addr = mk_ilsel_addr(bit);
69 shift = mk_ilsel_shift(bit);
70
71 pr_debug("%s: bit#%d: addr - 0x%08lx (shift %d, set %d)\n",
72 __func__, bit, addr, shift, set);
73
74 tmp = __raw_readw(addr);
75 tmp &= ~(0xf << shift);
76 tmp |= set << shift;
77 __raw_writew(tmp, addr);
78}
79
80/**
81 * ilsel_enable - Enable an ILSEL set.
82 * @set: ILSEL source (see ilsel_source_t enum in include/asm-sh/ilsel.h).
83 *
84 * Enables a given non-aliased ILSEL source (<= ILSEL_KEY) at the highest
85 * available interrupt level. Callers should take care to order callsites
86 * noting descending interrupt levels. Aliasing FPGA and external board
87 * IRQs need to use ilsel_enable_fixed().
88 *
89 * The return value is an IRQ number that can later be taken down with
90 * ilsel_disable().
91 */
92int ilsel_enable(ilsel_source_t set)
93{
94 unsigned int bit;
95
96 if (unlikely(set > ILSEL_KEY)) {
97 pr_err("Aliased sources must use ilsel_enable_fixed()\n");
98 return -EINVAL;
99 }
100
101 do {
102 bit = find_first_zero_bit(&ilsel_level_map, ILSEL_LEVELS);
103 } while (test_and_set_bit(bit, &ilsel_level_map));
104
105 __ilsel_enable(set, bit);
106
107 return bit;
108}
109EXPORT_SYMBOL_GPL(ilsel_enable);
110
111/**
112 * ilsel_enable_fixed - Enable an ILSEL set at a fixed interrupt level
113 * @set: ILSEL source (see ilsel_source_t enum in include/asm-sh/ilsel.h).
114 * @level: Interrupt level (1 - 15)
115 *
116 * Enables a given ILSEL source at a fixed interrupt level. Necessary
117 * both for level reservation as well as for aliased sources that only
118 * exist on special ILSEL#s.
119 *
120 * Returns an IRQ number (as ilsel_enable()).
121 */
122int ilsel_enable_fixed(ilsel_source_t set, unsigned int level)
123{
124 unsigned int bit = ilsel_offset(level - 1);
125
126 if (test_and_set_bit(bit, &ilsel_level_map))
127 return -EBUSY;
128
129 __ilsel_enable(set, bit);
130
131 return bit;
132}
133EXPORT_SYMBOL_GPL(ilsel_enable_fixed);
134
135/**
136 * ilsel_disable - Disable an ILSEL set
137 * @irq: Bit position for ILSEL set value (retval from enable routines)
138 *
139 * Disable a previously enabled ILSEL set.
140 */
141void ilsel_disable(unsigned int irq)
142{
143 unsigned long addr;
144 unsigned int tmp;
145
146 pr_notice("disabling ILSEL set %d\n", irq);
147
148 addr = mk_ilsel_addr(irq);
149
150 tmp = __raw_readw(addr);
151 tmp &= ~(0xf << mk_ilsel_shift(irq));
152 __raw_writew(tmp, addr);
153
154 clear_bit(irq, &ilsel_level_map);
155}
156EXPORT_SYMBOL_GPL(ilsel_disable);