[MFD] Cleanups suggested by Dmitri, Vojtech and lists.

These are small ucb1x00-ts cleanups, as suggested by Vojtech, Dmitri
and the lists.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 17 insertions, 48 deletions

diff --git a/drivers/mfd/ucb1x00-ts.c b/drivers/mfd/ucb1x00-ts.c
index 52e0699eeb8b..a851d65c7cfe 100644
--- a/drivers/mfd/ucb1x00-ts.c
+++ b/drivers/mfd/ucb1x00-ts.c
@@ -1,7 +1,8 @@
 /*
- *  linux/drivers/mfd/ucb1x00-ts.c
+ *  Touchscreen driver for UCB1x00-based touchscreens
  *
  *  Copyright (C) 2001 Russell King, All Rights Reserved.
+ *  Copyright (C) 2005 Pavel Machek
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -30,6 +31,7 @@
 #include <linux/device.h>
 #include <linux/suspend.h>
 #include <linux/slab.h>
+#include <linux/kthread.h>
 
 #include <asm/dma.h>
 #include <asm/semaphore.h>
@@ -42,10 +44,7 @@ struct ucb1x00_ts {
         struct ucb1x00          *ucb;
 
         wait_queue_head_t       irq_wait;
-        struct semaphore        sem;
-        struct completion       init_exit;
         struct task_struct      *rtask;
-        int                     use_count;
         u16                     x_res;
         u16                     y_res;
 
@@ -176,12 +175,6 @@ static int ucb1x00_thread(void *_ts)
         DECLARE_WAITQUEUE(wait, tsk);
         int valid;
 
-        ts->rtask = tsk;
-
-        daemonize("ktsd");
-        /* only want to receive SIGKILL */
-        allow_signal(SIGKILL);
-
         /*
          * We could run as a real-time thread.  However, thus far
          * this doesn't seem to be necessary.
@@ -189,12 +182,10 @@ static int ucb1x00_thread(void *_ts)
 //      tsk->policy = SCHED_FIFO;
 //      tsk->rt_priority = 1;
 
-        complete(&ts->init_exit);
-
         valid = 0;
 
         add_wait_queue(&ts->irq_wait, &wait);
-        for (;;) {
+        while (!kthread_should_stop()) {
                 unsigned int x, y, p, val;
                 signed long timeout;
 
@@ -212,10 +203,7 @@ static int ucb1x00_thread(void *_ts)
                 ucb1x00_ts_mode_int(ts);
                 ucb1x00_adc_disable(ts->ucb);
 
-                set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-                schedule_timeout(HZ / 100);
-                if (signal_pending(tsk))
-                        break;
+                msleep(10);
 
                 ucb1x00_enable(ts->ucb);
                 val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
@@ -256,14 +244,12 @@ static int ucb1x00_thread(void *_ts)
                 try_to_freeze();
 
                 schedule_timeout(timeout);
-                if (signal_pending(tsk))
-                        break;
         }
 
         remove_wait_queue(&ts->irq_wait, &wait);
 
         ts->rtask = NULL;
-        complete_and_exit(&ts->init_exit, 0);
+        return 0;
 }
 
 /*
@@ -282,14 +268,7 @@ static int ucb1x00_ts_open(struct input_dev *idev)
         struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
         int ret = 0;
 
-        if (down_interruptible(&ts->sem))
-                return -EINTR;
-
-        if (ts->use_count++ != 0)
-                goto out;
-
-        if (ts->rtask)
-                panic("ucb1x00: rtask running?");
+        BUG_ON(ts->rtask);
 
         init_waitqueue_head(&ts->irq_wait);
         ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
@@ -305,19 +284,16 @@ static int ucb1x00_ts_open(struct input_dev *idev)
         ts->y_res = ucb1x00_ts_read_yres(ts);
         ucb1x00_adc_disable(ts->ucb);
 
-        init_completion(&ts->init_exit);
-        ret = kernel_thread(ucb1x00_thread, ts, CLONE_KERNEL);
-        if (ret >= 0) {
-                wait_for_completion(&ts->init_exit);
+        ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd");
+        if (!IS_ERR(ts->rtask)) {
                 ret = 0;
         } else {
                 ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+                ts->rtask = NULL;
+                ret = -EFAULT;
         }
 
  out:
-        if (ret)
-                ts->use_count--;
-        up(&ts->sem);
         return ret;
 }
 
@@ -328,19 +304,13 @@ static void ucb1x00_ts_close(struct input_dev *idev)
 {
         struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
 
-        down(&ts->sem);
-        if (--ts->use_count == 0) {
-                if (ts->rtask) {
-                        send_sig(SIGKILL, ts->rtask, 1);
-                        wait_for_completion(&ts->init_exit);
-                }
+        if (ts->rtask)
+                kthread_stop(ts->rtask);
 
-                ucb1x00_enable(ts->ucb);
-                ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
-                ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
-                ucb1x00_disable(ts->ucb);
-        }
-        up(&ts->sem);
+        ucb1x00_enable(ts->ucb);
+        ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+        ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
+        ucb1x00_disable(ts->ucb);
 }
 
 #ifdef CONFIG_PM
@@ -379,7 +349,6 @@ static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
 
         ts->ucb = dev->ucb;
         ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
-        init_MUTEX(&ts->sem);
 
         ts->idev.name       = "Touchscreen panel";
         ts->idev.id.product = ts->ucb->id;