[MFD] Cleanups suggested by Dmitri, Vojtech and lists.
Pavel Machek [Sun, 11 Sep 2005 09:28:00 +0000 (10:28 +0100)]
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>

drivers/mfd/ucb1x00-ts.c

index 52e0699..a851d65 100644 (file)
@@ -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;