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 742d0c7bbbc2..1e0e20c0e082 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;