2 files changed, 304 insertions, 0 deletions

diff --git a/arch/sh/kernel/cpu/shmobile/Makefile b/arch/sh/kernel/cpu/shmobile/Makefile
index e8a5111e848..a39f88ea1a8 100644
--- a/arch/sh/kernel/cpu/shmobile/Makefile
+++ b/arch/sh/kernel/cpu/shmobile/Makefile
@@ -5,3 +5,4 @@
 # Power Management & Sleep mode
 obj-$(CONFIG_PM)        += pm.o sleep.o
 obj-$(CONFIG_CPU_IDLE)  += cpuidle.o
+obj-$(CONFIG_PM_RUNTIME)        += pm_runtime.o
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 00000000000..7c615b17e20
--- /dev/null
+++ b/arch/sh/kernel/cpu/shmobile/pm_runtime.c
@@ -0,0 +1,303 @@
+/*
+ * 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 && d->driver->pm && d->driver->pm->runtime_resume) {
+                hwblk_enable(hwblk_info, hwblk);
+                ret = 0;
+
+                if (test_bit(PDEV_ARCHDATA_FLAG_SUSP, &ad->flags)) {
+                        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 && d->driver->pm && d->driver->pm->runtime_suspend) {
+                BUG_ON(!test_bit(PDEV_ARCHDATA_FLAG_IDLE, &ad->flags));
+
+                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);