286 lines
6.4 KiB
C
286 lines
6.4 KiB
C
/* display7seg.c - 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 <linux/of.h>
|
|
#include <linux/of_device.h>
|
|
#include <asm/atomic.h>
|
|
#include <asm/uaccess.h> /* put_/get_user */
|
|
#include <asm/io.h>
|
|
|
|
#include <asm/display7seg.h>
|
|
|
|
#define D7S_MINOR 193
|
|
#define DRIVER_NAME "d7s"
|
|
#define PFX DRIVER_NAME ": "
|
|
|
|
static int sol_compat = 0; /* Solaris compatibility mode */
|
|
|
|
/* 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");
|
|
|
|
struct d7s {
|
|
void __iomem *regs;
|
|
bool flipped;
|
|
};
|
|
struct d7s *d7s_device;
|
|
|
|
/*
|
|
* 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 atomic_t d7s_users = ATOMIC_INIT(0);
|
|
|
|
static int d7s_open(struct inode *inode, struct file *f)
|
|
{
|
|
if (D7S_MINOR != iminor(inode))
|
|
return -ENODEV;
|
|
cycle_kernel_lock();
|
|
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) {
|
|
struct d7s *p = d7s_device;
|
|
u8 regval = 0;
|
|
|
|
regval = readb(p->regs);
|
|
if (p->flipped)
|
|
regval |= D7S_FLIP;
|
|
else
|
|
regval &= ~D7S_FLIP;
|
|
writeb(regval, p->regs);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct d7s *p = d7s_device;
|
|
u8 regs = readb(p->regs);
|
|
int error = 0;
|
|
u8 ireg = 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 (sol_compat) {
|
|
if (regs & D7S_FLIP)
|
|
ireg |= D7S_FLIP;
|
|
else
|
|
ireg &= ~D7S_FLIP;
|
|
}
|
|
writeb(ireg, p->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 */
|
|
if (regs & D7S_FLIP)
|
|
regs &= ~D7S_FLIP;
|
|
else
|
|
regs |= D7S_FLIP;
|
|
writeb(regs, p->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 = {
|
|
.minor = D7S_MINOR,
|
|
.name = DRIVER_NAME,
|
|
.fops = &d7s_fops
|
|
};
|
|
|
|
static int __devinit d7s_probe(struct of_device *op,
|
|
const struct of_device_id *match)
|
|
{
|
|
struct device_node *opts;
|
|
int err = -EINVAL;
|
|
struct d7s *p;
|
|
u8 regs;
|
|
|
|
if (d7s_device)
|
|
goto out;
|
|
|
|
p = kzalloc(sizeof(*p), GFP_KERNEL);
|
|
err = -ENOMEM;
|
|
if (!p)
|
|
goto out;
|
|
|
|
p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
|
|
if (!p->regs) {
|
|
printk(KERN_ERR PFX "Cannot map chip registers\n");
|
|
goto out_free;
|
|
}
|
|
|
|
err = misc_register(&d7s_miscdev);
|
|
if (err) {
|
|
printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
|
|
D7S_MINOR);
|
|
goto out_iounmap;
|
|
}
|
|
|
|
/* OBP option "d7s-flipped?" is honored as default for the
|
|
* device, and reset default when detached
|
|
*/
|
|
regs = readb(p->regs);
|
|
opts = of_find_node_by_path("/options");
|
|
if (opts &&
|
|
of_get_property(opts, "d7s-flipped?", NULL))
|
|
p->flipped = true;
|
|
|
|
if (p->flipped)
|
|
regs |= D7S_FLIP;
|
|
else
|
|
regs &= ~D7S_FLIP;
|
|
|
|
writeb(regs, p->regs);
|
|
|
|
printk(KERN_INFO PFX "7-Segment Display%s at [%s:0x%lx] %s\n",
|
|
op->node->full_name,
|
|
(regs & D7S_FLIP) ? " (FLIPPED)" : "",
|
|
op->resource[0].start,
|
|
sol_compat ? "in sol_compat mode" : "");
|
|
|
|
dev_set_drvdata(&op->dev, p);
|
|
d7s_device = p;
|
|
err = 0;
|
|
|
|
out:
|
|
return err;
|
|
|
|
out_iounmap:
|
|
of_iounmap(&op->resource[0], p->regs, sizeof(u8));
|
|
|
|
out_free:
|
|
kfree(p);
|
|
goto out;
|
|
}
|
|
|
|
static int __devexit d7s_remove(struct of_device *op)
|
|
{
|
|
struct d7s *p = dev_get_drvdata(&op->dev);
|
|
u8 regs = readb(p->regs);
|
|
|
|
/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
|
|
if (sol_compat) {
|
|
if (p->flipped)
|
|
regs |= D7S_FLIP;
|
|
else
|
|
regs &= ~D7S_FLIP;
|
|
writeb(regs, p->regs);
|
|
}
|
|
|
|
misc_deregister(&d7s_miscdev);
|
|
of_iounmap(&op->resource[0], p->regs, sizeof(u8));
|
|
kfree(p);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id d7s_match[] = {
|
|
{
|
|
.name = "display7seg",
|
|
},
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, d7s_match);
|
|
|
|
static struct of_platform_driver d7s_driver = {
|
|
.name = DRIVER_NAME,
|
|
.match_table = d7s_match,
|
|
.probe = d7s_probe,
|
|
.remove = __devexit_p(d7s_remove),
|
|
};
|
|
|
|
static int __init d7s_init(void)
|
|
{
|
|
return of_register_driver(&d7s_driver, &of_bus_type);
|
|
}
|
|
|
|
static void __exit d7s_exit(void)
|
|
{
|
|
of_unregister_driver(&d7s_driver);
|
|
}
|
|
|
|
module_init(d7s_init);
|
|
module_exit(d7s_exit);
|