[PATCH] Telecom Clock Driver for MPCBL0010 ATCA computer blade

Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 909 insertions, 0 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 7902c363068..fdf4370db99 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -1001,5 +1001,17 @@ config MMTIMER
 
 source "drivers/char/tpm/Kconfig"
 
+config TELCLOCK
+	tristate "Telecom clock driver for MPBL0010 ATCA SBC"
+	depends on EXPERIMENTAL
+	default n
+	help
+	  The telecom clock device is specific to the MPBL0010 ATCA computer and
+	  allows direct userspace access to the configuration of the telecom clock
+	  configuration settings.  This device is used for hardware synchronization
+	  across the ATCA backplane fabric.  Upon loading, the driver exports a
+	  sysfs directory, /sys/devices/platform/telco_clock, with a number of
+	  files for controlling the behavior of this hardware.
+
 endmenu
 
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 08f69287ea3..4aeae687e88 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_NWFLASH) += nwflash.o
 obj-$(CONFIG_SCx200_GPIO) += scx200_gpio.o
 obj-$(CONFIG_GPIO_VR41XX) += vr41xx_giu.o
 obj-$(CONFIG_TANBAC_TB0219) += tb0219.o
+obj-$(CONFIG_TELCLOCK) += tlclk.o
 
 obj-$(CONFIG_WATCHDOG)	+= watchdog/
 obj-$(CONFIG_MWAVE) += mwave/
diff --git a/drivers/char/tlclk.c b/drivers/char/tlclk.c
new file mode 100644
index 00000000000..18cdd4361dc
--- /dev/null
+++ b/drivers/char/tlclk.c
@@ -0,0 +1,896 @@
+/*
+ * Telecom Clock driver for Intel NetStructure(tm) MPCBL0010
+ *
+ * Copyright (C) 2005 Kontron Canada
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Send feedback to <sebastien.bouchard@ca.kontron.com> and the current
+ * Maintainer  <mark.gross@intel.com>
+ *
+ * Description : This is the TELECOM CLOCK module driver for the ATCA
+ * 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/delay.h>	/* udelay */
+#include <linux/slab.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/sysfs.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <asm/io.h>		/* inb/outb */
+#include <asm/uaccess.h>
+
+MODULE_AUTHOR("Sebastien Bouchard <sebastien.bouchard@ca.kontron.com>");
+MODULE_LICENSE("GPL");
+
+/*Hardware Reset of the PLL */
+#define RESET_ON	0x00
+#define RESET_OFF	0x01
+
+/* MODE SELECT */
+#define NORMAL_MODE 	0x00
+#define HOLDOVER_MODE	0x10
+#define FREERUN_MODE	0x20
+
+/* FILTER SELECT */
+#define FILTER_6HZ	0x04
+#define FILTER_12HZ	0x00
+
+/* SELECT REFERENCE FREQUENCY */
+#define REF_CLK1_8kHz		0x00
+#define REF_CLK2_19_44MHz	0x02
+
+/* Select primary or secondary redundant clock */
+#define PRIMARY_CLOCK	0x00
+#define SECONDARY_CLOCK	0x01
+
+/* CLOCK TRANSMISSION DEFINE */
+#define CLK_8kHz	0xff
+#define CLK_16_384MHz	0xfb
+
+#define CLK_1_544MHz	0x00
+#define CLK_2_048MHz	0x01
+#define CLK_4_096MHz	0x02
+#define CLK_6_312MHz	0x03
+#define CLK_8_192MHz	0x04
+#define CLK_19_440MHz	0x06
+
+#define CLK_8_592MHz	0x08
+#define CLK_11_184MHz	0x09
+#define CLK_34_368MHz	0x0b
+#define CLK_44_736MHz	0x0a
+
+/* RECEIVED REFERENCE */
+#define AMC_B1 0
+#define AMC_B2 1
+
+/* HARDWARE SWITCHING DEFINE */
+#define HW_ENABLE	0x80
+#define HW_DISABLE	0x00
+
+/* HARDWARE SWITCHING MODE DEFINE */
+#define PLL_HOLDOVER	0x40
+#define LOST_CLOCK	0x00
+
+/* ALARMS DEFINE */
+#define UNLOCK_MASK	0x10
+#define HOLDOVER_MASK	0x20
+#define SEC_LOST_MASK	0x40
+#define PRI_LOST_MASK	0x80
+
+/* INTERRUPT CAUSE DEFINE */
+
+#define PRI_LOS_01_MASK		0x01
+#define PRI_LOS_10_MASK		0x02
+
+#define SEC_LOS_01_MASK		0x04
+#define SEC_LOS_10_MASK		0x08
+
+#define HOLDOVER_01_MASK	0x10
+#define HOLDOVER_10_MASK	0x20
+
+#define UNLOCK_01_MASK		0x40
+#define UNLOCK_10_MASK		0x80
+
+struct tlclk_alarms {
+	__u32 lost_clocks;
+	__u32 lost_primary_clock;
+	__u32 lost_secondary_clock;
+	__u32 primary_clock_back;
+	__u32 secondary_clock_back;
+	__u32 switchover_primary;
+	__u32 switchover_secondary;
+	__u32 pll_holdover;
+	__u32 pll_end_holdover;
+	__u32 pll_lost_sync;
+	__u32 pll_sync;
+};
+/* Telecom clock I/O register definition */
+#define TLCLK_BASE 0xa08
+#define TLCLK_REG0 TLCLK_BASE
+#define TLCLK_REG1 (TLCLK_BASE+1)
+#define TLCLK_REG2 (TLCLK_BASE+2)
+#define TLCLK_REG3 (TLCLK_BASE+3)
+#define TLCLK_REG4 (TLCLK_BASE+4)
+#define TLCLK_REG5 (TLCLK_BASE+5)
+#define TLCLK_REG6 (TLCLK_BASE+6)
+#define TLCLK_REG7 (TLCLK_BASE+7)
+
+#define SET_PORT_BITS(port, mask, val) outb(((inb(port) & mask) | val), port)
+
+/* 0 = Dynamic allocation of the major device number */
+#define TLCLK_MAJOR 0
+
+/* sysfs interface definition:
+Upon loading the driver will create a sysfs directory under
+/sys/devices/platform/telco_clock.
+
+This directory exports the following interfaces.  There operation is
+documented in the MCPBL0010 TPS under the Telecom Clock API section, 11.4.
+alarms				:
+current_ref			:
+enable_clk3a_output		:
+enable_clk3b_output		:
+enable_clka0_output		:
+enable_clka1_output		:
+enable_clkb0_output		:
+enable_clkb1_output		:
+filter_select			:
+hardware_switching		:
+hardware_switching_mode		:
+interrupt_switch		:
+mode_select			:
+refalign			:
+reset				:
+select_amcb1_transmit_clock	:
+select_amcb2_transmit_clock	:
+select_redundant_clock		:
+select_ref_frequency		:
+test_mode			:
+
+All sysfs interfaces are integers in hex format, i.e echo 99 > refalign
+has the same effect as echo 0x99 > refalign.
+*/
+
+static unsigned int telclk_interrupt;
+
+static int int_events;		/* Event that generate a interrupt */
+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 struct tlclk_alarms *alarm_events;
+
+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 DECLARE_WAIT_QUEUE_HEAD(wq);
+
+static int tlclk_open(struct inode *inode, struct file *filp)
+{
+	int result;
+
+	/* Make sure there is no interrupt pending while
+	 * initialising interrupt handler */
+	inb(TLCLK_REG6);
+
+	/* 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) {
+		printk(KERN_ERR "telco_clock: Interrupt can't be reserved!\n");
+		return -EBUSY;
+	}
+	inb(TLCLK_REG6);	/* Clear interrupt events */
+
+	return 0;
+}
+
+static int tlclk_release(struct inode *inode, struct file *filp)
+{
+	free_irq(telclk_interrupt, tlclk_interrupt);
+
+	return 0;
+}
+
+ssize_t tlclk_read(struct file *filp, char __user *buf, size_t count,
+		loff_t *f_pos)
+{
+	if (count < sizeof(struct tlclk_alarms))
+		return -EIO;
+
+	wait_event_interruptible(wq, got_event);
+	if (copy_to_user(buf, alarm_events, sizeof(struct tlclk_alarms)))
+		return -EFAULT;
+
+	memset(alarm_events, 0, sizeof(struct tlclk_alarms));
+	got_event = 0;
+
+	return  sizeof(struct tlclk_alarms);
+}
+
+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 = {
+	.read = tlclk_read,
+	.write = tlclk_write,
+	.open = tlclk_open,
+	.release = tlclk_release,
+
+};
+
+static struct miscdevice tlclk_miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "telco_clock",
+	.fops = &tlclk_fops,
+};
+
+static ssize_t show_current_ref(struct device *d,
+		struct device_attribute *attr, char *buf)
+{
+	unsigned long ret_val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&event_lock, flags);
+	ret_val = ((inb(TLCLK_REG1) & 0x08) >> 3);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return sprintf(buf, "0x%lX\n", ret_val);
+}
+
+static DEVICE_ATTR(current_ref, S_IRUGO, show_current_ref, NULL);
+
+
+static ssize_t show_interrupt_switch(struct device *d,
+		struct device_attribute *attr, char *buf)
+{
+	unsigned long ret_val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&event_lock, flags);
+	ret_val = inb(TLCLK_REG6);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return sprintf(buf, "0x%lX\n", ret_val);
+}
+
+static DEVICE_ATTR(interrupt_switch, S_IRUGO,
+		show_interrupt_switch, NULL);
+
+static ssize_t show_alarms(struct device *d,
+		struct device_attribute *attr,  char *buf)
+{
+	unsigned long ret_val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&event_lock, flags);
+	ret_val = (inb(TLCLK_REG2) & 0xf0);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return sprintf(buf, "0x%lX\n", ret_val);
+}
+
+static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
+
+static ssize_t store_enable_clk3b_output(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, ": tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG3, 0x7f, val << 7);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(enable_clk3b_output, S_IWUGO, NULL,
+		store_enable_clk3b_output);
+
+static ssize_t store_enable_clk3a_output(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long flags;
+	unsigned long tmp;
+	unsigned char val;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG3, 0xbf, val << 6);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(enable_clk3a_output, S_IWUGO, NULL,
+		store_enable_clk3a_output);
+
+static ssize_t store_enable_clkb1_output(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long flags;
+	unsigned long tmp;
+	unsigned char val;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG2, 0xf7, val << 3);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(enable_clkb1_output, S_IWUGO, NULL,
+		store_enable_clkb1_output);
+
+
+static ssize_t store_enable_clka1_output(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long flags;
+	unsigned long tmp;
+	unsigned char val;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG2, 0xfb, val << 2);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(enable_clka1_output, S_IWUGO, NULL,
+		store_enable_clka1_output);
+
+static ssize_t store_enable_clkb0_output(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long flags;
+	unsigned long tmp;
+	unsigned char val;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG2, 0xfd, val << 1);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(enable_clkb0_output, S_IWUGO, NULL,
+		store_enable_clkb0_output);
+
+static ssize_t store_enable_clka0_output(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long flags;
+	unsigned long tmp;
+	unsigned char val;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG2, 0xfe, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(enable_clka0_output, S_IWUGO, NULL,
+		store_enable_clka0_output);
+
+static ssize_t store_test_mode(struct device *d,
+		struct device_attribute *attr,  const char *buf, size_t count)
+{
+	unsigned long flags;
+	unsigned long tmp;
+	unsigned char val;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG4, 0xfd, 2);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(test_mode, S_IWUGO, NULL, store_test_mode);
+
+static ssize_t store_select_amcb2_transmit_clock(struct device *d,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long flags;
+	unsigned long tmp;
+	unsigned char val;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+		if ((val == CLK_8kHz) || (val == CLK_16_384MHz)) {
+			SET_PORT_BITS(TLCLK_REG3, 0xc7, 0x28);
+			SET_PORT_BITS(TLCLK_REG1, 0xfb, ~val);
+		} else if (val >= CLK_8_592MHz) {
+			SET_PORT_BITS(TLCLK_REG3, 0xc7, 0x38);
+			switch (val) {
+			case CLK_8_592MHz:
+				SET_PORT_BITS(TLCLK_REG0, 0xfc, 1);
+				break;
+			case CLK_11_184MHz:
+				SET_PORT_BITS(TLCLK_REG0, 0xfc, 0);
+				break;
+			case CLK_34_368MHz:
+				SET_PORT_BITS(TLCLK_REG0, 0xfc, 3);
+				break;
+			case CLK_44_736MHz:
+				SET_PORT_BITS(TLCLK_REG0, 0xfc, 2);
+				break;
+			}
+		} else
+			SET_PORT_BITS(TLCLK_REG3, 0xc7, val << 3);
+
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(select_amcb2_transmit_clock, S_IWUGO, NULL,
+	store_select_amcb2_transmit_clock);
+
+static ssize_t store_select_amcb1_transmit_clock(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+		if ((val == CLK_8kHz) || (val == CLK_16_384MHz)) {
+			SET_PORT_BITS(TLCLK_REG3, 0xf8, 0x5);
+			SET_PORT_BITS(TLCLK_REG1, 0xfb, ~val);
+		} else if (val >= CLK_8_592MHz) {
+			SET_PORT_BITS(TLCLK_REG3, 0xf8, 0x7);
+			switch (val) {
+			case CLK_8_592MHz:
+				SET_PORT_BITS(TLCLK_REG0, 0xfc, 1);
+				break;
+			case CLK_11_184MHz:
+				SET_PORT_BITS(TLCLK_REG0, 0xfc, 0);
+				break;
+			case CLK_34_368MHz:
+				SET_PORT_BITS(TLCLK_REG0, 0xfc, 3);
+				break;
+			case CLK_44_736MHz:
+				SET_PORT_BITS(TLCLK_REG0, 0xfc, 2);
+				break;
+			}
+		} else
+			SET_PORT_BITS(TLCLK_REG3, 0xf8, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(select_amcb1_transmit_clock, S_IWUGO, NULL,
+		store_select_amcb1_transmit_clock);
+
+static ssize_t store_select_redundant_clock(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG1, 0xfe, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(select_redundant_clock, S_IWUGO, NULL,
+		store_select_redundant_clock);
+
+static ssize_t store_select_ref_frequency(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG1, 0xfd, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(select_ref_frequency, S_IWUGO, NULL,
+		store_select_ref_frequency);
+
+static ssize_t store_filter_select(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG0, 0xfb, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(filter_select, S_IWUGO, NULL, store_filter_select);
+
+static ssize_t store_hardware_switching_mode(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG0, 0xbf, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(hardware_switching_mode, S_IWUGO, NULL,
+		store_hardware_switching_mode);
+
+static ssize_t store_hardware_switching(struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG0, 0x7f, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(hardware_switching, S_IWUGO, NULL,
+		store_hardware_switching);
+
+static ssize_t store_refalign (struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG0, 0xf7, 0);
+	udelay(2);
+	SET_PORT_BITS(TLCLK_REG0, 0xf7, 0x08);
+	udelay(2);
+	SET_PORT_BITS(TLCLK_REG0, 0xf7, 0);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(refalign, S_IWUGO, NULL, store_refalign);
+
+static ssize_t store_mode_select (struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG0, 0xcf, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(mode_select, S_IWUGO, NULL, store_mode_select);
+
+static ssize_t store_reset (struct device *d,
+		 struct device_attribute *attr, const char *buf, size_t count)
+{
+	unsigned long tmp;
+	unsigned char val;
+	unsigned long flags;
+
+	sscanf(buf, "%lX", &tmp);
+	dev_dbg(d, "tmp = 0x%lX\n", tmp);
+
+	val = (unsigned char)tmp;
+	spin_lock_irqsave(&event_lock, flags);
+	SET_PORT_BITS(TLCLK_REG4, 0xfd, val);
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return strnlen(buf, count);
+}
+
+static DEVICE_ATTR(reset, S_IWUGO, NULL, store_reset);
+
+static struct attribute *tlclk_sysfs_entries[] = {
+	&dev_attr_current_ref.attr,
+	&dev_attr_interrupt_switch.attr,
+	&dev_attr_alarms.attr,
+	&dev_attr_enable_clk3a_output.attr,
+	&dev_attr_enable_clk3b_output.attr,
+	&dev_attr_enable_clkb1_output.attr,
+	&dev_attr_enable_clka1_output.attr,
+	&dev_attr_enable_clkb0_output.attr,
+	&dev_attr_enable_clka0_output.attr,
+	&dev_attr_test_mode.attr,
+	&dev_attr_select_amcb1_transmit_clock.attr,
+	&dev_attr_select_amcb2_transmit_clock.attr,
+	&dev_attr_select_redundant_clock.attr,
+	&dev_attr_select_ref_frequency.attr,
+	&dev_attr_filter_select.attr,
+	&dev_attr_hardware_switching_mode.attr,
+	&dev_attr_hardware_switching.attr,
+	&dev_attr_refalign.attr,
+	&dev_attr_mode_select.attr,
+	&dev_attr_reset.attr,
+	NULL
+};
+
+static struct attribute_group tlclk_attribute_group = {
+	.name = NULL,		/* put in device directory */
+	.attrs = tlclk_sysfs_entries,
+};
+
+static struct platform_device *tlclk_device;
+
+static int __init tlclk_init(void)
+{
+	int ret;
+
+	ret = register_chrdev(tlclk_major, "telco_clock", &tlclk_fops);
+	if (ret < 0) {
+		printk(KERN_ERR "telco_clock: can't get major! %d\n", tlclk_major);
+		return ret;
+	}
+	alarm_events = kzalloc( sizeof(struct tlclk_alarms), GFP_KERNEL);
+	if (!alarm_events)
+		goto out1;
+
+	/* Read telecom clock IRQ number (Set by BIOS) */
+	if (!request_region(TLCLK_BASE, 8, "telco_clock")) {
+		printk(KERN_ERR "tlclk: request_region failed! 0x%X\n",
+			TLCLK_BASE);
+		ret = -EBUSY;
+		goto out2;
+	}
+	telclk_interrupt = (inb(TLCLK_REG7) & 0x0f);
+
+	if (0x0F == telclk_interrupt ) { /* not MCPBL0010 ? */
+		printk(KERN_ERR "telclk_interrup = 0x%x non-mcpbl0010 hw\n",
+			telclk_interrupt);
+		ret = -ENXIO;
+		goto out3;
+	}
+
+	init_timer(&switchover_timer);
+
+	ret = misc_register(&tlclk_miscdev);
+	if (ret < 0) {
+		printk(KERN_ERR " misc_register retruns %d\n", ret);
+		ret = -EBUSY;
+		goto out3;
+	}
+
+	tlclk_device = platform_device_register_simple("telco_clock",
+				-1, NULL, 0);
+	if (!tlclk_device) {
+		printk(KERN_ERR " platform_device_register retruns 0x%X\n",
+			(unsigned int) tlclk_device);
+		ret = -EBUSY;
+		goto out4;
+	}
+
+	ret = sysfs_create_group(&tlclk_device->dev.kobj,
+			&tlclk_attribute_group);
+	if (ret) {
+		printk(KERN_ERR "failed to create sysfs device attributes\n");
+		sysfs_remove_group(&tlclk_device->dev.kobj,
+			&tlclk_attribute_group);
+		goto out5;
+	}
+
+	return 0;
+out5:
+	platform_device_unregister(tlclk_device);
+out4:
+	misc_deregister(&tlclk_miscdev);
+out3:
+	release_region(TLCLK_BASE, 8);
+out2:
+	kfree(alarm_events);
+out1:
+	unregister_chrdev(tlclk_major, "telco_clock");
+	return ret;
+}
+
+static void __exit tlclk_cleanup(void)
+{
+	sysfs_remove_group(&tlclk_device->dev.kobj, &tlclk_attribute_group);
+	platform_device_unregister(tlclk_device);
+	misc_deregister(&tlclk_miscdev);
+	unregister_chrdev(tlclk_major, "telco_clock");
+
+	release_region(TLCLK_BASE, 8);
+	del_timer_sync(&switchover_timer);
+	kfree(alarm_events);
+
+}
+
+static void switchover_timeout(unsigned long data)
+{
+	if ((data & 1)) {
+		if ((inb(TLCLK_REG1) & 0x08) != (data & 0x08))
+			alarm_events->switchover_primary++;
+	} else {
+		if ((inb(TLCLK_REG1) & 0x08) != (data & 0x08))
+			alarm_events->switchover_secondary++;
+	}
+
+	/* Alarm processing is done, wake up read task */
+	del_timer(&switchover_timer);
+	got_event = 1;
+	wake_up(&wq);
+}
+
+static irqreturn_t tlclk_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&event_lock, flags);
+	/* Read and clear interrupt events */
+	int_events = inb(TLCLK_REG6);
+
+	/* Primary_Los changed from 0 to 1 ? */
+	if (int_events & PRI_LOS_01_MASK) {
+		if (inb(TLCLK_REG2) & SEC_LOST_MASK)
+			alarm_events->lost_clocks++;
+		else
+			alarm_events->lost_primary_clock++;
+	}
+
+	/* Primary_Los changed from 1 to 0 ? */
+	if (int_events & PRI_LOS_10_MASK) {
+		alarm_events->primary_clock_back++;
+		SET_PORT_BITS(TLCLK_REG1, 0xFE, 1);
+	}
+	/* Secondary_Los changed from 0 to 1 ? */
+	if (int_events & SEC_LOS_01_MASK) {
+		if (inb(TLCLK_REG2) & PRI_LOST_MASK)
+			alarm_events->lost_clocks++;
+		else
+			alarm_events->lost_secondary_clock++;
+	}
+	/* Secondary_Los changed from 1 to 0 ? */
+	if (int_events & SEC_LOS_10_MASK) {
+		alarm_events->secondary_clock_back++;
+		SET_PORT_BITS(TLCLK_REG1, 0xFE, 0);
+	}
+	if (int_events & HOLDOVER_10_MASK)
+		alarm_events->pll_end_holdover++;
+
+	if (int_events & UNLOCK_01_MASK)
+		alarm_events->pll_lost_sync++;
+
+	if (int_events & UNLOCK_10_MASK)
+		alarm_events->pll_sync++;
+
+	/* Holdover changed from 0 to 1 ? */
+	if (int_events & HOLDOVER_01_MASK) {
+		alarm_events->pll_holdover++;
+
+		/* TIMEOUT in ~10ms */
+		switchover_timer.expires = jiffies + msecs_to_jiffies(10);
+		switchover_timer.data = inb(TLCLK_REG1);
+		add_timer(&switchover_timer);
+	} else {
+		got_event = 1;
+		wake_up(&wq);
+	}
+	spin_unlock_irqrestore(&event_lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+module_init(tlclk_init);
+module_exit(tlclk_cleanup);