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path: root/drivers/char/tlclk.c
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Diffstat (limited to 'drivers/char/tlclk.c')
-rw-r--r--drivers/char/tlclk.c85
1 files changed, 51 insertions, 34 deletions
diff --git a/drivers/char/tlclk.c b/drivers/char/tlclk.c
index f58ad7f6826..100cd1de993 100644
--- a/drivers/char/tlclk.c
+++ b/drivers/char/tlclk.c
@@ -27,17 +27,17 @@
* MPCBL0010 ATCA computer.
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
-#include <linux/sched.h>
#include <linux/kernel.h> /* printk() */
#include <linux/fs.h> /* everything... */
#include <linux/errno.h> /* error codes */
+#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
+#include <linux/mutex.h>
#include <linux/timer.h>
#include <linux/sysfs.h>
#include <linux/device.h>
@@ -187,6 +187,7 @@ static int got_event; /* if events processing have been done */
static void switchover_timeout(unsigned long data);
static struct timer_list switchover_timer =
TIMER_INITIALIZER(switchover_timeout , 0, 0);
+static unsigned long tlclk_timer_data;
static struct tlclk_alarms *alarm_events;
@@ -194,14 +195,26 @@ static DEFINE_SPINLOCK(event_lock);
static int tlclk_major = TLCLK_MAJOR;
-static irqreturn_t tlclk_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static irqreturn_t tlclk_interrupt(int irq, void *dev_id);
static DECLARE_WAIT_QUEUE_HEAD(wq);
+static unsigned long useflags;
+static DEFINE_MUTEX(tlclk_mutex);
+
static int tlclk_open(struct inode *inode, struct file *filp)
{
int result;
+ mutex_lock(&tlclk_mutex);
+ if (test_and_set_bit(0, &useflags)) {
+ result = -EBUSY;
+ /* this legacy device is always one per system and it doesn't
+ * know how to handle multiple concurrent clients.
+ */
+ goto out;
+ }
+
/* Make sure there is no interrupt pending while
* initialising interrupt handler */
inb(TLCLK_REG6);
@@ -209,19 +222,21 @@ static int tlclk_open(struct inode *inode, struct file *filp)
/* This device is wired through the FPGA IO space of the ATCA blade
* we can't share this IRQ */
result = request_irq(telclk_interrupt, &tlclk_interrupt,
- SA_INTERRUPT, "telco_clock", tlclk_interrupt);
- if (result == -EBUSY) {
+ 0, "telco_clock", tlclk_interrupt);
+ if (result == -EBUSY)
printk(KERN_ERR "tlclk: Interrupt can't be reserved.\n");
- return -EBUSY;
- }
- inb(TLCLK_REG6); /* Clear interrupt events */
+ else
+ inb(TLCLK_REG6); /* Clear interrupt events */
- return 0;
+out:
+ mutex_unlock(&tlclk_mutex);
+ return result;
}
static int tlclk_release(struct inode *inode, struct file *filp)
{
free_irq(telclk_interrupt, tlclk_interrupt);
+ clear_bit(0, &useflags);
return 0;
}
@@ -231,28 +246,28 @@ static ssize_t tlclk_read(struct file *filp, char __user *buf, size_t count,
{
if (count < sizeof(struct tlclk_alarms))
return -EIO;
+ if (mutex_lock_interruptible(&tlclk_mutex))
+ return -EINTR;
+
wait_event_interruptible(wq, got_event);
- if (copy_to_user(buf, alarm_events, sizeof(struct tlclk_alarms)))
+ if (copy_to_user(buf, alarm_events, sizeof(struct tlclk_alarms))) {
+ mutex_unlock(&tlclk_mutex);
return -EFAULT;
+ }
memset(alarm_events, 0, sizeof(struct tlclk_alarms));
got_event = 0;
+ mutex_unlock(&tlclk_mutex);
return sizeof(struct tlclk_alarms);
}
-static ssize_t tlclk_write(struct file *filp, const char __user *buf, size_t count,
- loff_t *f_pos)
-{
- return 0;
-}
-
-static struct file_operations tlclk_fops = {
+static const struct file_operations tlclk_fops = {
.read = tlclk_read,
- .write = tlclk_write,
.open = tlclk_open,
.release = tlclk_release,
+ .llseek = noop_llseek,
};
@@ -343,7 +358,7 @@ static ssize_t store_received_ref_clk3b(struct device *d,
val = (unsigned char)tmp;
spin_lock_irqsave(&event_lock, flags);
- SET_PORT_BITS(TLCLK_REG1, 0xef, val << 1);
+ SET_PORT_BITS(TLCLK_REG1, 0xdf, val << 1);
spin_unlock_irqrestore(&event_lock, flags);
return strnlen(buf, count);
@@ -541,7 +556,7 @@ static ssize_t store_select_amcb1_transmit_clock(struct device *d,
SET_PORT_BITS(TLCLK_REG3, 0xf8, 0x7);
switch (val) {
case CLK_8_592MHz:
- SET_PORT_BITS(TLCLK_REG0, 0xfc, 1);
+ SET_PORT_BITS(TLCLK_REG0, 0xfc, 2);
break;
case CLK_11_184MHz:
SET_PORT_BITS(TLCLK_REG0, 0xfc, 0);
@@ -550,7 +565,7 @@ static ssize_t store_select_amcb1_transmit_clock(struct device *d,
SET_PORT_BITS(TLCLK_REG0, 0xfc, 3);
break;
case CLK_44_736MHz:
- SET_PORT_BITS(TLCLK_REG0, 0xfc, 2);
+ SET_PORT_BITS(TLCLK_REG0, 0xfc, 1);
break;
}
} else
@@ -769,8 +784,10 @@ static int __init tlclk_init(void)
}
tlclk_major = ret;
alarm_events = kzalloc( sizeof(struct tlclk_alarms), GFP_KERNEL);
- if (!alarm_events)
+ if (!alarm_events) {
+ ret = -ENOMEM;
goto out1;
+ }
/* Read telecom clock IRQ number (Set by BIOS) */
if (!request_region(TLCLK_BASE, 8, "telco_clock")) {
@@ -782,7 +799,7 @@ static int __init tlclk_init(void)
telclk_interrupt = (inb(TLCLK_REG7) & 0x0f);
if (0x0F == telclk_interrupt ) { /* not MCPBL0010 ? */
- printk(KERN_ERR "telclk_interrup = 0x%x non-mcpbl0010 hw.\n",
+ printk(KERN_ERR "telclk_interrupt = 0x%x non-mcpbl0010 hw.\n",
telclk_interrupt);
ret = -ENXIO;
goto out3;
@@ -793,15 +810,14 @@ static int __init tlclk_init(void)
ret = misc_register(&tlclk_miscdev);
if (ret < 0) {
printk(KERN_ERR "tlclk: misc_register returns %d.\n", ret);
- ret = -EBUSY;
goto out3;
}
tlclk_device = platform_device_register_simple("telco_clock",
-1, NULL, 0);
- if (!tlclk_device) {
+ if (IS_ERR(tlclk_device)) {
printk(KERN_ERR "tlclk: platform_device_register failed.\n");
- ret = -EBUSY;
+ ret = PTR_ERR(tlclk_device);
goto out4;
}
@@ -809,8 +825,6 @@ static int __init tlclk_init(void)
&tlclk_attribute_group);
if (ret) {
printk(KERN_ERR "tlclk: failed to create sysfs device attributes.\n");
- sysfs_remove_group(&tlclk_device->dev.kobj,
- &tlclk_attribute_group);
goto out5;
}
@@ -843,11 +857,13 @@ static void __exit tlclk_cleanup(void)
static void switchover_timeout(unsigned long data)
{
- if ((data & 1)) {
- if ((inb(TLCLK_REG1) & 0x08) != (data & 0x08))
+ unsigned long flags = *(unsigned long *) data;
+
+ if ((flags & 1)) {
+ if ((inb(TLCLK_REG1) & 0x08) != (flags & 0x08))
alarm_events->switchover_primary++;
} else {
- if ((inb(TLCLK_REG1) & 0x08) != (data & 0x08))
+ if ((inb(TLCLK_REG1) & 0x08) != (flags & 0x08))
alarm_events->switchover_secondary++;
}
@@ -857,7 +873,7 @@ static void switchover_timeout(unsigned long data)
wake_up(&wq);
}
-static irqreturn_t tlclk_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t tlclk_interrupt(int irq, void *dev_id)
{
unsigned long flags;
@@ -905,8 +921,9 @@ static irqreturn_t tlclk_interrupt(int irq, void *dev_id, struct pt_regs *regs)
/* TIMEOUT in ~10ms */
switchover_timer.expires = jiffies + msecs_to_jiffies(10);
- switchover_timer.data = inb(TLCLK_REG1);
- add_timer(&switchover_timer);
+ tlclk_timer_data = inb(TLCLK_REG1);
+ switchover_timer.data = (unsigned long) &tlclk_timer_data;
+ mod_timer(&switchover_timer, switchover_timer.expires);
} else {
got_event = 1;
wake_up(&wq);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-07 19:44:46 +0000