1 files changed, 308 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/shmobile/pm_runtime.c b/arch/sh/kernel/cpu/shmobile/pm_runtime.c
new file mode 100644
index 0000000..6dcb816
--- /dev/null
+++ b/arch/sh/kernel/cpu/shmobile/pm_runtime.c
@@ -0,0 +1,308 @@
+/*
+ * arch/sh/kernel/cpu/shmobile/pm_runtime.c
+ *
+ * Runtime PM support code for SuperH Mobile
+ *
+ *  Copyright (C) 2009 Magnus Damm
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <asm/hwblk.h>
+
+static DEFINE_SPINLOCK(hwblk_lock);
+static LIST_HEAD(hwblk_idle_list);
+static struct work_struct hwblk_work;
+
+extern struct hwblk_info *hwblk_info;
+
+static void platform_pm_runtime_not_idle(struct platform_device *pdev)
+{
+	unsigned long flags;
+
+	/* remove device from idle list */
+	spin_lock_irqsave(&hwblk_lock, flags);
+	if (test_bit(PDEV_ARCHDATA_FLAG_IDLE, &pdev->archdata.flags)) {
+		list_del(&pdev->archdata.entry);
+		__clear_bit(PDEV_ARCHDATA_FLAG_IDLE, &pdev->archdata.flags);
+	}
+	spin_unlock_irqrestore(&hwblk_lock, flags);
+}
+
+static int __platform_pm_runtime_resume(struct platform_device *pdev)
+{
+	struct device *d = &pdev->dev;
+	struct pdev_archdata *ad = &pdev->archdata;
+	int hwblk = ad->hwblk_id;
+	int ret = -ENOSYS;
+
+	dev_dbg(d, "__platform_pm_runtime_resume() [%d]\n", hwblk);
+
+	if (d->driver) {
+		hwblk_enable(hwblk_info, hwblk);
+		ret = 0;
+
+		if (test_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags)) {
+			if (d->driver->pm && d->driver->pm->runtime_resume)
+				ret = d->driver->pm->runtime_resume(d);
+
+			if (!ret)
+				clear_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags);
+			else
+				hwblk_disable(hwblk_info, hwblk);
+		}
+	}
+
+	dev_dbg(d, "__platform_pm_runtime_resume() [%d] - returns %d\n",
+		hwblk, ret);
+
+	return ret;
+}
+
+static int __platform_pm_runtime_suspend(struct platform_device *pdev)
+{
+	struct device *d = &pdev->dev;
+	struct pdev_archdata *ad = &pdev->archdata;
+	int hwblk = ad->hwblk_id;
+	int ret = -ENOSYS;
+
+	dev_dbg(d, "__platform_pm_runtime_suspend() [%d]\n", hwblk);
+
+	if (d->driver) {
+		BUG_ON(!test_bit(PDEV_ARCHDATA_FLAG_IDLE, &ad->flags));
+		ret = 0;
+
+		if (d->driver->pm && d->driver->pm->runtime_suspend) {
+			hwblk_enable(hwblk_info, hwblk);
+			ret = d->driver->pm->runtime_suspend(d);
+			hwblk_disable(hwblk_info, hwblk);
+		}
+
+		if (!ret) {
+			set_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags);
+			platform_pm_runtime_not_idle(pdev);
+			hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_IDLE);
+		}
+	}
+
+	dev_dbg(d, "__platform_pm_runtime_suspend() [%d] - returns %d\n",
+		hwblk, ret);
+
+	return ret;
+}
+
+static void platform_pm_runtime_work(struct work_struct *work)
+{
+	struct platform_device *pdev;
+	unsigned long flags;
+	int ret;
+
+	/* go through the idle list and suspend one device at a time */
+	do {
+		spin_lock_irqsave(&hwblk_lock, flags);
+		if (list_empty(&hwblk_idle_list))
+			pdev = NULL;
+		else
+			pdev = list_first_entry(&hwblk_idle_list,
+						struct platform_device,
+						archdata.entry);
+		spin_unlock_irqrestore(&hwblk_lock, flags);
+
+		if (pdev) {
+			mutex_lock(&pdev->archdata.mutex);
+			ret = __platform_pm_runtime_suspend(pdev);
+
+			/* at this point the platform device may be:
+			 * suspended: ret = 0, FLAG_SUSP set, clock stopped
+			 * failed: ret < 0, FLAG_IDLE set, clock stopped
+			 */
+			mutex_unlock(&pdev->archdata.mutex);
+		} else {
+			ret = -ENODEV;
+		}
+	} while (!ret);
+}
+
+/* this function gets called from cpuidle context when all devices in the
+ * main power domain are unused but some are counted as idle, ie the hwblk
+ * counter values are (HWBLK_CNT_USAGE == 0) && (HWBLK_CNT_IDLE != 0)
+ */
+void platform_pm_runtime_suspend_idle(void)
+{
+	queue_work(pm_wq, &hwblk_work);
+}
+
+int platform_pm_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct pdev_archdata *ad = &pdev->archdata;
+	unsigned long flags;
+	int hwblk = ad->hwblk_id;
+	int ret = 0;
+
+	dev_dbg(dev, "platform_pm_runtime_suspend() [%d]\n", hwblk);
+
+	/* ignore off-chip platform devices */
+	if (!hwblk)
+		goto out;
+
+	/* interrupt context not allowed */
+	might_sleep();
+
+	/* catch misconfigured drivers not starting with resume */
+	if (test_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* serialize */
+	mutex_lock(&ad->mutex);
+
+	/* disable clock */
+	hwblk_disable(hwblk_info, hwblk);
+
+	/* put device on idle list */
+	spin_lock_irqsave(&hwblk_lock, flags);
+	list_add_tail(&pdev->archdata.entry, &hwblk_idle_list);
+	__set_bit(PDEV_ARCHDATA_FLAG_IDLE, &pdev->archdata.flags);
+	spin_unlock_irqrestore(&hwblk_lock, flags);
+
+	/* increase idle count */
+	hwblk_cnt_inc(hwblk_info, hwblk, HWBLK_CNT_IDLE);
+
+	/* at this point the platform device is:
+	 * idle: ret = 0, FLAG_IDLE set, clock stopped
+	 */
+	mutex_unlock(&ad->mutex);
+
+out:
+	dev_dbg(dev, "platform_pm_runtime_suspend() [%d] returns %d\n",
+		hwblk, ret);
+
+	return ret;
+}
+
+int platform_pm_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct pdev_archdata *ad = &pdev->archdata;
+	int hwblk = ad->hwblk_id;
+	int ret = 0;
+
+	dev_dbg(dev, "platform_pm_runtime_resume() [%d]\n", hwblk);
+
+	/* ignore off-chip platform devices */
+	if (!hwblk)
+		goto out;
+
+	/* interrupt context not allowed */
+	might_sleep();
+
+	/* serialize */
+	mutex_lock(&ad->mutex);
+
+	/* make sure device is removed from idle list */
+	platform_pm_runtime_not_idle(pdev);
+
+	/* decrease idle count */
+	if (!test_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags) &&
+	    !test_bit(PDEV_ARCHDATA_FLAG_SUSP, &pdev->archdata.flags))
+		hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_IDLE);
+
+	/* resume the device if needed */
+	ret = __platform_pm_runtime_resume(pdev);
+
+	/* the driver has been initialized now, so clear the init flag */
+	clear_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
+
+	/* at this point the platform device may be:
+	 * resumed: ret = 0, flags = 0, clock started
+	 * failed: ret < 0, FLAG_SUSP set, clock stopped
+	 */
+	mutex_unlock(&ad->mutex);
+out:
+	dev_dbg(dev, "platform_pm_runtime_resume() [%d] returns %d\n",
+		hwblk, ret);
+
+	return ret;
+}
+
+int platform_pm_runtime_idle(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	int hwblk = pdev->archdata.hwblk_id;
+	int ret = 0;
+
+	dev_dbg(dev, "platform_pm_runtime_idle() [%d]\n", hwblk);
+
+	/* ignore off-chip platform devices */
+	if (!hwblk)
+		goto out;
+
+	/* interrupt context not allowed, use pm_runtime_put()! */
+	might_sleep();
+
+	/* suspend synchronously to disable clocks immediately */
+	ret = pm_runtime_suspend(dev);
+out:
+	dev_dbg(dev, "platform_pm_runtime_idle() [%d] done!\n", hwblk);
+	return ret;
+}
+
+static int platform_bus_notify(struct notifier_block *nb,
+			       unsigned long action, void *data)
+{
+	struct device *dev = data;
+	struct platform_device *pdev = to_platform_device(dev);
+	int hwblk = pdev->archdata.hwblk_id;
+
+	/* ignore off-chip platform devices */
+	if (!hwblk)
+		return 0;
+
+	switch (action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		INIT_LIST_HEAD(&pdev->archdata.entry);
+		mutex_init(&pdev->archdata.mutex);
+		/* platform devices without drivers should be disabled */
+		hwblk_enable(hwblk_info, hwblk);
+		hwblk_disable(hwblk_info, hwblk);
+		/* make sure driver re-inits itself once */
+		__set_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
+		break;
+	/* TODO: add BUS_NOTIFY_BIND_DRIVER and increase idle count */
+	case BUS_NOTIFY_BOUND_DRIVER:
+		/* keep track of number of devices in use per hwblk */
+		hwblk_cnt_inc(hwblk_info, hwblk, HWBLK_CNT_DEVICES);
+		break;
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		/* keep track of number of devices in use per hwblk */
+		hwblk_cnt_dec(hwblk_info, hwblk, HWBLK_CNT_DEVICES);
+		/* make sure driver re-inits itself once */
+		__set_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
+		break;
+	case BUS_NOTIFY_DEL_DEVICE:
+		break;
+	}
+	return 0;
+}
+
+static struct notifier_block platform_bus_notifier = {
+	.notifier_call = platform_bus_notify
+};
+
+static int __init sh_pm_runtime_init(void)
+{
+	INIT_WORK(&hwblk_work, platform_pm_runtime_work);
+
+	bus_register_notifier(&platform_bus_type, &platform_bus_notifier);
+	return 0;
+}
+core_initcall(sh_pm_runtime_init);