MFD: ucb1x00: convert to use genirq

Convert the ucb1x00 driver to use genirq's interrupt services, rather
than its own private implementation.  This allows a wider range of
drivers to use the GPIO interrupts (such as the gpio_keys driver)
without being aware of the UCB1x00's private IRQ system.

This prevents the UCB1x00 core driver from being built as a module,
so adjust the configuration to add that restriction.

Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 30 insertions, 7 deletions

diff --git a/drivers/mfd/ucb1x00-ts.c b/drivers/mfd/ucb1x00-ts.c
index 742d0c7bbbc..1e0e20c0e08 100644
--- a/drivers/mfd/ucb1x00-ts.c
+++ b/drivers/mfd/ucb1x00-ts.c
@@ -20,8 +20,9 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/init.h>
-#include <linux/smp.h>
+#include <linux/interrupt.h>
 #include <linux/sched.h>
+#include <linux/spinlock.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/string.h>
@@ -41,6 +42,8 @@ struct ucb1x00_ts {
 	struct input_dev	*idev;
 	struct ucb1x00		*ucb;
 
+	spinlock_t		irq_lock;
+	unsigned		irq_disabled;
 	wait_queue_head_t	irq_wait;
 	struct task_struct	*rtask;
 	u16			x_res;
@@ -237,7 +240,12 @@ static int ucb1x00_thread(void *_ts)
 		if (ucb1x00_ts_pen_down(ts)) {
 			set_current_state(TASK_INTERRUPTIBLE);
 
-			ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING);
+			spin_lock_irq(&ts->irq_lock);
+			if (ts->irq_disabled) {
+				ts->irq_disabled = 0;
+				enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX);
+			}
+			spin_unlock_irq(&ts->irq_lock);
 			ucb1x00_disable(ts->ucb);
 
 			/*
@@ -280,23 +288,37 @@ static int ucb1x00_thread(void *_ts)
  * We only detect touch screen _touches_ with this interrupt
  * handler, and even then we just schedule our task.
  */
-static void ucb1x00_ts_irq(int idx, void *id)
+static irqreturn_t ucb1x00_ts_irq(int irq, void *id)
 {
 	struct ucb1x00_ts *ts = id;
 
-	ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
+	spin_lock(&ts->irq_lock);
+	ts->irq_disabled = 1;
+	disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX);
+	spin_unlock(&ts->irq_lock);
 	wake_up(&ts->irq_wait);
+
+	return IRQ_HANDLED;
 }
 
 static int ucb1x00_ts_open(struct input_dev *idev)
 {
 	struct ucb1x00_ts *ts = input_get_drvdata(idev);
+	unsigned long flags = 0;
 	int ret = 0;
 
 	BUG_ON(ts->rtask);
 
+	if (machine_is_collie())
+		flags = IRQF_TRIGGER_RISING;
+	else
+		flags = IRQF_TRIGGER_FALLING;
+
+	ts->irq_disabled = 0;
+
 	init_waitqueue_head(&ts->irq_wait);
-	ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
+	ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq,
+			  flags, "ucb1x00-ts", ts);
 	if (ret < 0)
 		goto out;
 
@@ -313,7 +335,7 @@ static int ucb1x00_ts_open(struct input_dev *idev)
 	if (!IS_ERR(ts->rtask)) {
 		ret = 0;
 	} else {
-		ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+		free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
 		ts->rtask = NULL;
 		ret = -EFAULT;
 	}
@@ -333,7 +355,7 @@ static void ucb1x00_ts_close(struct input_dev *idev)
 		kthread_stop(ts->rtask);
 
 	ucb1x00_enable(ts->ucb);
-	ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+	free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
 	ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
 	ucb1x00_disable(ts->ucb);
 }
@@ -358,6 +380,7 @@ static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
 	ts->ucb = dev->ucb;
 	ts->idev = idev;
 	ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
+	spin_lock_init(&ts->irq_lock);
 
 	idev->name       = "Touchscreen panel";
 	idev->id.product = ts->ucb->id;