mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-07 22:46:41 +07:00
00977a59b9
Many struct file_operations in the kernel can be "const". Marking them const moves these to the .rodata section, which avoids false sharing with potential dirty data. In addition it'll catch accidental writes at compile time to these shared resources. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
243 lines
5.8 KiB
C
243 lines
5.8 KiB
C
/* $Id: display7seg.c,v 1.6 2002/01/08 16:00:16 davem Exp $
|
|
*
|
|
* display7seg - Driver implementation for the 7-segment display
|
|
* present on Sun Microsystems CP1400 and CP1500
|
|
*
|
|
* Copyright (c) 2000 Eric Brower (ebrower@usa.net)
|
|
*
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/major.h>
|
|
#include <linux/init.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/ioport.h> /* request_region */
|
|
#include <linux/smp_lock.h>
|
|
#include <asm/atomic.h>
|
|
#include <asm/ebus.h> /* EBus device */
|
|
#include <asm/oplib.h> /* OpenProm Library */
|
|
#include <asm/uaccess.h> /* put_/get_user */
|
|
|
|
#include <asm/display7seg.h>
|
|
|
|
#define D7S_MINOR 193
|
|
#define D7S_OBPNAME "display7seg"
|
|
#define D7S_DEVNAME "d7s"
|
|
|
|
static int sol_compat = 0; /* Solaris compatibility mode */
|
|
|
|
#ifdef MODULE
|
|
|
|
/* Solaris compatibility flag -
|
|
* The Solaris implementation omits support for several
|
|
* documented driver features (ref Sun doc 806-0180-03).
|
|
* By default, this module supports the documented driver
|
|
* abilities, rather than the Solaris implementation:
|
|
*
|
|
* 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
|
|
* upon closure of device or module unload.
|
|
* 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
|
|
* FLIP bit
|
|
*
|
|
* If you wish the device to operate as under Solaris,
|
|
* omitting above features, set this parameter to non-zero.
|
|
*/
|
|
module_param
|
|
(sol_compat, int, 0);
|
|
MODULE_PARM_DESC
|
|
(sol_compat,
|
|
"Disables documented functionality omitted from Solaris driver");
|
|
|
|
MODULE_AUTHOR
|
|
("Eric Brower <ebrower@usa.net>");
|
|
MODULE_DESCRIPTION
|
|
("7-Segment Display driver for Sun Microsystems CP1400/1500");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_SUPPORTED_DEVICE
|
|
("d7s");
|
|
#endif /* ifdef MODULE */
|
|
|
|
/*
|
|
* Register block address- see header for details
|
|
* -----------------------------------------
|
|
* | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 |
|
|
* -----------------------------------------
|
|
*
|
|
* DP - Toggles decimal point on/off
|
|
* ALARM - Toggles "Alarm" LED green/red
|
|
* FLIP - Inverts display for upside-down mounted board
|
|
* bits 0-4 - 7-segment display contents
|
|
*/
|
|
static void __iomem* d7s_regs;
|
|
|
|
static inline void d7s_free(void)
|
|
{
|
|
iounmap(d7s_regs);
|
|
}
|
|
|
|
static inline int d7s_obpflipped(void)
|
|
{
|
|
int opt_node;
|
|
|
|
opt_node = prom_getchild(prom_root_node);
|
|
opt_node = prom_searchsiblings(opt_node, "options");
|
|
return ((-1 != prom_getintdefault(opt_node, "d7s-flipped?", -1)) ? 0 : 1);
|
|
}
|
|
|
|
static atomic_t d7s_users = ATOMIC_INIT(0);
|
|
|
|
static int d7s_open(struct inode *inode, struct file *f)
|
|
{
|
|
if (D7S_MINOR != iminor(inode))
|
|
return -ENODEV;
|
|
atomic_inc(&d7s_users);
|
|
return 0;
|
|
}
|
|
|
|
static int d7s_release(struct inode *inode, struct file *f)
|
|
{
|
|
/* Reset flipped state to OBP default only if
|
|
* no other users have the device open and we
|
|
* are not operating in solaris-compat mode
|
|
*/
|
|
if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
|
|
int regval = 0;
|
|
|
|
regval = readb(d7s_regs);
|
|
(0 == d7s_obpflipped()) ?
|
|
writeb(regval |= D7S_FLIP, d7s_regs):
|
|
writeb(regval &= ~D7S_FLIP, d7s_regs);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
__u8 regs = readb(d7s_regs);
|
|
__u8 ireg = 0;
|
|
int error = 0;
|
|
|
|
if (D7S_MINOR != iminor(file->f_path.dentry->d_inode))
|
|
return -ENODEV;
|
|
|
|
lock_kernel();
|
|
switch (cmd) {
|
|
case D7SIOCWR:
|
|
/* assign device register values
|
|
* we mask-out D7S_FLIP if in sol_compat mode
|
|
*/
|
|
if (get_user(ireg, (int __user *) arg)) {
|
|
error = -EFAULT;
|
|
break;
|
|
}
|
|
if (0 != sol_compat) {
|
|
(regs & D7S_FLIP) ?
|
|
(ireg |= D7S_FLIP) : (ireg &= ~D7S_FLIP);
|
|
}
|
|
writeb(ireg, d7s_regs);
|
|
break;
|
|
|
|
case D7SIOCRD:
|
|
/* retrieve device register values
|
|
* NOTE: Solaris implementation returns D7S_FLIP bit
|
|
* as toggled by user, even though it does not honor it.
|
|
* This driver will not misinform you about the state
|
|
* of your hardware while in sol_compat mode
|
|
*/
|
|
if (put_user(regs, (int __user *) arg)) {
|
|
error = -EFAULT;
|
|
break;
|
|
}
|
|
break;
|
|
|
|
case D7SIOCTM:
|
|
/* toggle device mode-- flip display orientation */
|
|
(regs & D7S_FLIP) ?
|
|
(regs &= ~D7S_FLIP) : (regs |= D7S_FLIP);
|
|
writeb(regs, d7s_regs);
|
|
break;
|
|
};
|
|
unlock_kernel();
|
|
|
|
return error;
|
|
}
|
|
|
|
static const struct file_operations d7s_fops = {
|
|
.owner = THIS_MODULE,
|
|
.unlocked_ioctl = d7s_ioctl,
|
|
.compat_ioctl = d7s_ioctl,
|
|
.open = d7s_open,
|
|
.release = d7s_release,
|
|
};
|
|
|
|
static struct miscdevice d7s_miscdev = { D7S_MINOR, D7S_DEVNAME, &d7s_fops };
|
|
|
|
static int __init d7s_init(void)
|
|
{
|
|
struct linux_ebus *ebus = NULL;
|
|
struct linux_ebus_device *edev = NULL;
|
|
int iTmp = 0, regs = 0;
|
|
|
|
for_each_ebus(ebus) {
|
|
for_each_ebusdev(edev, ebus) {
|
|
if (!strcmp(edev->prom_node->name, D7S_OBPNAME))
|
|
goto ebus_done;
|
|
}
|
|
}
|
|
|
|
ebus_done:
|
|
if(!edev) {
|
|
printk("%s: unable to locate device\n", D7S_DEVNAME);
|
|
return -ENODEV;
|
|
}
|
|
|
|
d7s_regs = ioremap(edev->resource[0].start, sizeof(__u8));
|
|
|
|
iTmp = misc_register(&d7s_miscdev);
|
|
if (0 != iTmp) {
|
|
printk("%s: unable to acquire miscdevice minor %i\n",
|
|
D7S_DEVNAME, D7S_MINOR);
|
|
iounmap(d7s_regs);
|
|
return iTmp;
|
|
}
|
|
|
|
/* OBP option "d7s-flipped?" is honored as default
|
|
* for the device, and reset default when detached
|
|
*/
|
|
regs = readb(d7s_regs);
|
|
iTmp = d7s_obpflipped();
|
|
(0 == iTmp) ?
|
|
writeb(regs |= D7S_FLIP, d7s_regs):
|
|
writeb(regs &= ~D7S_FLIP, d7s_regs);
|
|
|
|
printk("%s: 7-Segment Display%s at 0x%lx %s\n",
|
|
D7S_DEVNAME,
|
|
(0 == iTmp) ? (" (FLIPPED)") : (""),
|
|
edev->resource[0].start,
|
|
(0 != sol_compat) ? ("in sol_compat mode") : (""));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit d7s_cleanup(void)
|
|
{
|
|
int regs = readb(d7s_regs);
|
|
|
|
/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
|
|
if (0 == sol_compat) {
|
|
(0 == d7s_obpflipped()) ?
|
|
writeb(regs |= D7S_FLIP, d7s_regs):
|
|
writeb(regs &= ~D7S_FLIP, d7s_regs);
|
|
}
|
|
|
|
misc_deregister(&d7s_miscdev);
|
|
d7s_free();
|
|
}
|
|
|
|
module_init(d7s_init);
|
|
module_exit(d7s_cleanup);
|