Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / sound / core / rtctimer.c

diff --git a/kernel/sound/core/rtctimer.c b/kernel/sound/core/rtctimer.c
new file mode 100644 (file)
index 0000000..f3420d1
--- /dev/null
+++ b/kernel/sound/core/rtctimer.c
@@ -0,0 +1,187 @@
+/*
+ *  RTC based high-frequency timer
+ *
+ *  Copyright (C) 2000 Takashi Iwai
+ *     based on rtctimer.c by Steve Ratcliffe
+ *
+ *   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.  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/log2.h>
+#include <sound/core.h>
+#include <sound/timer.h>
+
+#if IS_ENABLED(CONFIG_RTC)
+
+#include <linux/mc146818rtc.h>
+
+#define RTC_FREQ       1024            /* default frequency */
+#define NANO_SEC       1000000000L     /* 10^9 in sec */
+
+/*
+ * prototypes
+ */
+static int rtctimer_open(struct snd_timer *t);
+static int rtctimer_close(struct snd_timer *t);
+static int rtctimer_start(struct snd_timer *t);
+static int rtctimer_stop(struct snd_timer *t);
+
+
+/*
+ * The hardware dependent description for this timer.
+ */
+static struct snd_timer_hardware rtc_hw = {
+       .flags =        SNDRV_TIMER_HW_AUTO |
+                       SNDRV_TIMER_HW_FIRST |
+                       SNDRV_TIMER_HW_TASKLET,
+       .ticks =        100000000L,             /* FIXME: XXX */
+       .open =         rtctimer_open,
+       .close =        rtctimer_close,
+       .start =        rtctimer_start,
+       .stop =         rtctimer_stop,
+};
+
+static int rtctimer_freq = RTC_FREQ;           /* frequency */
+static struct snd_timer *rtctimer;
+static struct tasklet_struct rtc_tasklet;
+static rtc_task_t rtc_task;
+
+
+static int
+rtctimer_open(struct snd_timer *t)
+{
+       int err;
+
+       err = rtc_register(&rtc_task);
+       if (err < 0)
+               return err;
+       t->private_data = &rtc_task;
+       return 0;
+}
+
+static int
+rtctimer_close(struct snd_timer *t)
+{
+       rtc_task_t *rtc = t->private_data;
+       if (rtc) {
+               rtc_unregister(rtc);
+               tasklet_kill(&rtc_tasklet);
+               t->private_data = NULL;
+       }
+       return 0;
+}
+
+static int
+rtctimer_start(struct snd_timer *timer)
+{
+       rtc_task_t *rtc = timer->private_data;
+       if (snd_BUG_ON(!rtc))
+               return -EINVAL;
+       rtc_control(rtc, RTC_IRQP_SET, rtctimer_freq);
+       rtc_control(rtc, RTC_PIE_ON, 0);
+       return 0;
+}
+
+static int
+rtctimer_stop(struct snd_timer *timer)
+{
+       rtc_task_t *rtc = timer->private_data;
+       if (snd_BUG_ON(!rtc))
+               return -EINVAL;
+       rtc_control(rtc, RTC_PIE_OFF, 0);
+       return 0;
+}
+
+static void rtctimer_tasklet(unsigned long data)
+{
+       snd_timer_interrupt((struct snd_timer *)data, 1);
+}
+
+/*
+ * interrupt
+ */
+static void rtctimer_interrupt(void *private_data)
+{
+       tasklet_schedule(private_data);
+}
+
+
+/*
+ *  ENTRY functions
+ */
+static int __init rtctimer_init(void)
+{
+       int err;
+       struct snd_timer *timer;
+
+       if (rtctimer_freq < 2 || rtctimer_freq > 8192 ||
+           !is_power_of_2(rtctimer_freq)) {
+               pr_err("ALSA: rtctimer: invalid frequency %d\n", rtctimer_freq);
+               return -EINVAL;
+       }
+
+       /* Create a new timer and set up the fields */
+       err = snd_timer_global_new("rtc", SNDRV_TIMER_GLOBAL_RTC, &timer);
+       if (err < 0)
+               return err;
+
+       timer->module = THIS_MODULE;
+       strcpy(timer->name, "RTC timer");
+       timer->hw = rtc_hw;
+       timer->hw.resolution = NANO_SEC / rtctimer_freq;
+
+       tasklet_init(&rtc_tasklet, rtctimer_tasklet, (unsigned long)timer);
+
+       /* set up RTC callback */
+       rtc_task.func = rtctimer_interrupt;
+       rtc_task.private_data = &rtc_tasklet;
+
+       err = snd_timer_global_register(timer);
+       if (err < 0) {
+               snd_timer_global_free(timer);
+               return err;
+       }
+       rtctimer = timer; /* remember this */
+
+       return 0;
+}
+
+static void __exit rtctimer_exit(void)
+{
+       if (rtctimer) {
+               snd_timer_global_free(rtctimer);
+               rtctimer = NULL;
+       }
+}
+
+
+/*
+ * exported stuff
+ */
+module_init(rtctimer_init)
+module_exit(rtctimer_exit)
+
+module_param(rtctimer_freq, int, 0444);
+MODULE_PARM_DESC(rtctimer_freq, "timer frequency in Hz");
+
+MODULE_LICENSE("GPL");
+
+MODULE_ALIAS("snd-timer-" __stringify(SNDRV_TIMER_GLOBAL_RTC));
+
+#endif /* IS_ENABLED(CONFIG_RTC) */