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1// SPDX-License-Identifier: GPL-2.0-only
2/* flash.c: Allow mmap access to the OBP Flash, for OBP updates.
3 *
4 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
5 */
6
7#include <linux/module.h>
8#include <linux/types.h>
9#include <linux/errno.h>
10#include <linux/miscdevice.h>
11#include <linux/fcntl.h>
12#include <linux/poll.h>
13#include <linux/mutex.h>
14#include <linux/spinlock.h>
15#include <linux/mm.h>
16#include <linux/of.h>
17#include <linux/platform_device.h>
18
19#include <linux/uaccess.h>
20#include <asm/io.h>
21#include <asm/upa.h>
22
23static DEFINE_MUTEX(flash_mutex);
24static DEFINE_SPINLOCK(flash_lock);
25static struct {
26 unsigned long read_base; /* Physical read address */
27 unsigned long write_base; /* Physical write address */
28 unsigned long read_size; /* Size of read area */
29 unsigned long write_size; /* Size of write area */
30 unsigned long busy; /* In use? */
31} flash;
32
33static int
34flash_mmap(struct file *file, struct vm_area_struct *vma)
35{
36 unsigned long addr;
37 unsigned long size;
38
39 spin_lock(&flash_lock);
40 if (flash.read_base == flash.write_base) {
41 addr = flash.read_base;
42 size = flash.read_size;
43 } else {
44 if ((vma->vm_flags & VM_READ) &&
45 (vma->vm_flags & VM_WRITE)) {
46 spin_unlock(&flash_lock);
47 return -EINVAL;
48 }
49 if (vma->vm_flags & VM_READ) {
50 addr = flash.read_base;
51 size = flash.read_size;
52 } else if (vma->vm_flags & VM_WRITE) {
53 addr = flash.write_base;
54 size = flash.write_size;
55 } else {
56 spin_unlock(&flash_lock);
57 return -ENXIO;
58 }
59 }
60 spin_unlock(&flash_lock);
61
62 if ((vma->vm_pgoff << PAGE_SHIFT) > size)
63 return -ENXIO;
64 addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
65
66 if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
67 size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
68
69 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
70
71 if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
72 return -EAGAIN;
73
74 return 0;
75}
76
77static long long
78flash_llseek(struct file *file, long long offset, int origin)
79{
80 mutex_lock(&flash_mutex);
81 switch (origin) {
82 case 0:
83 file->f_pos = offset;
84 break;
85 case 1:
86 file->f_pos += offset;
87 if (file->f_pos > flash.read_size)
88 file->f_pos = flash.read_size;
89 break;
90 case 2:
91 file->f_pos = flash.read_size;
92 break;
93 default:
94 mutex_unlock(&flash_mutex);
95 return -EINVAL;
96 }
97 mutex_unlock(&flash_mutex);
98 return file->f_pos;
99}
100
101static ssize_t
102flash_read(struct file * file, char __user * buf,
103 size_t count, loff_t *ppos)
104{
105 loff_t p = *ppos;
106 int i;
107
108 if (count > flash.read_size - p)
109 count = flash.read_size - p;
110
111 for (i = 0; i < count; i++) {
112 u8 data = upa_readb(flash.read_base + p + i);
113 if (put_user(data, buf))
114 return -EFAULT;
115 buf++;
116 }
117
118 *ppos += count;
119 return count;
120}
121
122static int
123flash_open(struct inode *inode, struct file *file)
124{
125 mutex_lock(&flash_mutex);
126 if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
127 mutex_unlock(&flash_mutex);
128 return -EBUSY;
129 }
130
131 mutex_unlock(&flash_mutex);
132 return 0;
133}
134
135static int
136flash_release(struct inode *inode, struct file *file)
137{
138 spin_lock(&flash_lock);
139 flash.busy = 0;
140 spin_unlock(&flash_lock);
141
142 return 0;
143}
144
145static const struct file_operations flash_fops = {
146 /* no write to the Flash, use mmap
147 * and play flash dependent tricks.
148 */
149 .owner = THIS_MODULE,
150 .llseek = flash_llseek,
151 .read = flash_read,
152 .mmap = flash_mmap,
153 .open = flash_open,
154 .release = flash_release,
155};
156
157static struct miscdevice flash_dev = { SBUS_FLASH_MINOR, "flash", &flash_fops };
158
159static int flash_probe(struct platform_device *op)
160{
161 struct device_node *dp = op->dev.of_node;
162 struct device_node *parent;
163
164 parent = dp->parent;
165
166 if (!of_node_name_eq(parent, "sbus") &&
167 !of_node_name_eq(parent, "sbi") &&
168 !of_node_name_eq(parent, "ebus"))
169 return -ENODEV;
170
171 flash.read_base = op->resource[0].start;
172 flash.read_size = resource_size(&op->resource[0]);
173 if (op->resource[1].flags) {
174 flash.write_base = op->resource[1].start;
175 flash.write_size = resource_size(&op->resource[1]);
176 } else {
177 flash.write_base = op->resource[0].start;
178 flash.write_size = resource_size(&op->resource[0]);
179 }
180 flash.busy = 0;
181
182 printk(KERN_INFO "%pOF: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
183 op->dev.of_node,
184 flash.read_base, flash.read_size,
185 flash.write_base, flash.write_size);
186
187 return misc_register(&flash_dev);
188}
189
190static int flash_remove(struct platform_device *op)
191{
192 misc_deregister(&flash_dev);
193
194 return 0;
195}
196
197static const struct of_device_id flash_match[] = {
198 {
199 .name = "flashprom",
200 },
201 {},
202};
203MODULE_DEVICE_TABLE(of, flash_match);
204
205static struct platform_driver flash_driver = {
206 .driver = {
207 .name = "flash",
208 .of_match_table = flash_match,
209 },
210 .probe = flash_probe,
211 .remove = flash_remove,
212};
213
214module_platform_driver(flash_driver);
215
216MODULE_LICENSE("GPL");
1/* flash.c: Allow mmap access to the OBP Flash, for OBP updates.
2 *
3 * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
4 */
5
6#include <linux/module.h>
7#include <linux/types.h>
8#include <linux/errno.h>
9#include <linux/miscdevice.h>
10#include <linux/fcntl.h>
11#include <linux/poll.h>
12#include <linux/mutex.h>
13#include <linux/spinlock.h>
14#include <linux/mm.h>
15#include <linux/of.h>
16#include <linux/of_device.h>
17
18#include <asm/uaccess.h>
19#include <asm/pgtable.h>
20#include <asm/io.h>
21#include <asm/upa.h>
22
23static DEFINE_MUTEX(flash_mutex);
24static DEFINE_SPINLOCK(flash_lock);
25static struct {
26 unsigned long read_base; /* Physical read address */
27 unsigned long write_base; /* Physical write address */
28 unsigned long read_size; /* Size of read area */
29 unsigned long write_size; /* Size of write area */
30 unsigned long busy; /* In use? */
31} flash;
32
33#define FLASH_MINOR 152
34
35static int
36flash_mmap(struct file *file, struct vm_area_struct *vma)
37{
38 unsigned long addr;
39 unsigned long size;
40
41 spin_lock(&flash_lock);
42 if (flash.read_base == flash.write_base) {
43 addr = flash.read_base;
44 size = flash.read_size;
45 } else {
46 if ((vma->vm_flags & VM_READ) &&
47 (vma->vm_flags & VM_WRITE)) {
48 spin_unlock(&flash_lock);
49 return -EINVAL;
50 }
51 if (vma->vm_flags & VM_READ) {
52 addr = flash.read_base;
53 size = flash.read_size;
54 } else if (vma->vm_flags & VM_WRITE) {
55 addr = flash.write_base;
56 size = flash.write_size;
57 } else {
58 spin_unlock(&flash_lock);
59 return -ENXIO;
60 }
61 }
62 spin_unlock(&flash_lock);
63
64 if ((vma->vm_pgoff << PAGE_SHIFT) > size)
65 return -ENXIO;
66 addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
67
68 if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
69 size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
70
71 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
72
73 if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
74 return -EAGAIN;
75
76 return 0;
77}
78
79static long long
80flash_llseek(struct file *file, long long offset, int origin)
81{
82 mutex_lock(&flash_mutex);
83 switch (origin) {
84 case 0:
85 file->f_pos = offset;
86 break;
87 case 1:
88 file->f_pos += offset;
89 if (file->f_pos > flash.read_size)
90 file->f_pos = flash.read_size;
91 break;
92 case 2:
93 file->f_pos = flash.read_size;
94 break;
95 default:
96 mutex_unlock(&flash_mutex);
97 return -EINVAL;
98 }
99 mutex_unlock(&flash_mutex);
100 return file->f_pos;
101}
102
103static ssize_t
104flash_read(struct file * file, char __user * buf,
105 size_t count, loff_t *ppos)
106{
107 loff_t p = *ppos;
108 int i;
109
110 if (count > flash.read_size - p)
111 count = flash.read_size - p;
112
113 for (i = 0; i < count; i++) {
114 u8 data = upa_readb(flash.read_base + p + i);
115 if (put_user(data, buf))
116 return -EFAULT;
117 buf++;
118 }
119
120 *ppos += count;
121 return count;
122}
123
124static int
125flash_open(struct inode *inode, struct file *file)
126{
127 mutex_lock(&flash_mutex);
128 if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
129 mutex_unlock(&flash_mutex);
130 return -EBUSY;
131 }
132
133 mutex_unlock(&flash_mutex);
134 return 0;
135}
136
137static int
138flash_release(struct inode *inode, struct file *file)
139{
140 spin_lock(&flash_lock);
141 flash.busy = 0;
142 spin_unlock(&flash_lock);
143
144 return 0;
145}
146
147static const struct file_operations flash_fops = {
148 /* no write to the Flash, use mmap
149 * and play flash dependent tricks.
150 */
151 .owner = THIS_MODULE,
152 .llseek = flash_llseek,
153 .read = flash_read,
154 .mmap = flash_mmap,
155 .open = flash_open,
156 .release = flash_release,
157};
158
159static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
160
161static int flash_probe(struct platform_device *op)
162{
163 struct device_node *dp = op->dev.of_node;
164 struct device_node *parent;
165
166 parent = dp->parent;
167
168 if (strcmp(parent->name, "sbus") &&
169 strcmp(parent->name, "sbi") &&
170 strcmp(parent->name, "ebus"))
171 return -ENODEV;
172
173 flash.read_base = op->resource[0].start;
174 flash.read_size = resource_size(&op->resource[0]);
175 if (op->resource[1].flags) {
176 flash.write_base = op->resource[1].start;
177 flash.write_size = resource_size(&op->resource[1]);
178 } else {
179 flash.write_base = op->resource[0].start;
180 flash.write_size = resource_size(&op->resource[0]);
181 }
182 flash.busy = 0;
183
184 printk(KERN_INFO "%s: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
185 op->dev.of_node->full_name,
186 flash.read_base, flash.read_size,
187 flash.write_base, flash.write_size);
188
189 return misc_register(&flash_dev);
190}
191
192static int flash_remove(struct platform_device *op)
193{
194 misc_deregister(&flash_dev);
195
196 return 0;
197}
198
199static const struct of_device_id flash_match[] = {
200 {
201 .name = "flashprom",
202 },
203 {},
204};
205MODULE_DEVICE_TABLE(of, flash_match);
206
207static struct platform_driver flash_driver = {
208 .driver = {
209 .name = "flash",
210 .of_match_table = flash_match,
211 },
212 .probe = flash_probe,
213 .remove = flash_remove,
214};
215
216module_platform_driver(flash_driver);
217
218MODULE_LICENSE("GPL");