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path: root/drivers/amba/bus.c
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Diffstat (limited to 'drivers/amba/bus.c')
-rw-r--r--drivers/amba/bus.c234
1 files changed, 121 insertions, 113 deletions
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index ecc304149067..939ca220bf78 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -56,31 +56,28 @@ amba_lookup(const struct amba_id *table, struct amba_device *dev)
return NULL;
}
-static int amba_match(struct device *dev, struct device_driver *drv)
+static int amba_get_enable_pclk(struct amba_device *pcdev)
{
- struct amba_device *pcdev = to_amba_device(dev);
- struct amba_driver *pcdrv = to_amba_driver(drv);
+ int ret;
- /* When driver_override is set, only bind to the matching driver */
- if (pcdev->driver_override)
- return !strcmp(pcdev->driver_override, drv->name);
+ pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
+ if (IS_ERR(pcdev->pclk))
+ return PTR_ERR(pcdev->pclk);
- return amba_lookup(pcdrv->id_table, pcdev) != NULL;
+ ret = clk_prepare_enable(pcdev->pclk);
+ if (ret)
+ clk_put(pcdev->pclk);
+
+ return ret;
}
-static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
+static void amba_put_disable_pclk(struct amba_device *pcdev)
{
- struct amba_device *pcdev = to_amba_device(dev);
- int retval = 0;
-
- retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
- if (retval)
- return retval;
-
- retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
- return retval;
+ clk_disable_unprepare(pcdev->pclk);
+ clk_put(pcdev->pclk);
}
+
static ssize_t driver_override_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
@@ -152,102 +149,29 @@ static struct attribute *amba_dev_attrs[] = {
};
ATTRIBUTE_GROUPS(amba_dev);
-#ifdef CONFIG_PM
-/*
- * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
- * enable/disable the bus clock at runtime PM suspend/resume as this
- * does not result in loss of context.
- */
-static int amba_pm_runtime_suspend(struct device *dev)
+static int amba_match(struct device *dev, struct device_driver *drv)
{
struct amba_device *pcdev = to_amba_device(dev);
- int ret = pm_generic_runtime_suspend(dev);
+ struct amba_driver *pcdrv = to_amba_driver(drv);
- if (ret == 0 && dev->driver) {
- if (pm_runtime_is_irq_safe(dev))
- clk_disable(pcdev->pclk);
- else
- clk_disable_unprepare(pcdev->pclk);
- }
+ /* When driver_override is set, only bind to the matching driver */
+ if (pcdev->driver_override)
+ return !strcmp(pcdev->driver_override, drv->name);
- return ret;
+ return amba_lookup(pcdrv->id_table, pcdev) != NULL;
}
-static int amba_pm_runtime_resume(struct device *dev)
+static int amba_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct amba_device *pcdev = to_amba_device(dev);
- int ret;
-
- if (dev->driver) {
- if (pm_runtime_is_irq_safe(dev))
- ret = clk_enable(pcdev->pclk);
- else
- ret = clk_prepare_enable(pcdev->pclk);
- /* Failure is probably fatal to the system, but... */
- if (ret)
- return ret;
- }
-
- return pm_generic_runtime_resume(dev);
-}
-#endif /* CONFIG_PM */
-
-static const struct dev_pm_ops amba_pm = {
- .suspend = pm_generic_suspend,
- .resume = pm_generic_resume,
- .freeze = pm_generic_freeze,
- .thaw = pm_generic_thaw,
- .poweroff = pm_generic_poweroff,
- .restore = pm_generic_restore,
- SET_RUNTIME_PM_OPS(
- amba_pm_runtime_suspend,
- amba_pm_runtime_resume,
- NULL
- )
-};
-
-/*
- * Primecells are part of the Advanced Microcontroller Bus Architecture,
- * so we call the bus "amba".
- * DMA configuration for platform and AMBA bus is same. So here we reuse
- * platform's DMA config routine.
- */
-struct bus_type amba_bustype = {
- .name = "amba",
- .dev_groups = amba_dev_groups,
- .match = amba_match,
- .uevent = amba_uevent,
- .dma_configure = platform_dma_configure,
- .pm = &amba_pm,
-};
-EXPORT_SYMBOL_GPL(amba_bustype);
-
-static int __init amba_init(void)
-{
- return bus_register(&amba_bustype);
-}
-
-postcore_initcall(amba_init);
-
-static int amba_get_enable_pclk(struct amba_device *pcdev)
-{
- int ret;
-
- pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
- if (IS_ERR(pcdev->pclk))
- return PTR_ERR(pcdev->pclk);
-
- ret = clk_prepare_enable(pcdev->pclk);
- if (ret)
- clk_put(pcdev->pclk);
+ int retval = 0;
- return ret;
-}
+ retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
+ if (retval)
+ return retval;
-static void amba_put_disable_pclk(struct amba_device *pcdev)
-{
- clk_disable_unprepare(pcdev->pclk);
- clk_put(pcdev->pclk);
+ retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
+ return retval;
}
/*
@@ -299,10 +223,10 @@ static int amba_remove(struct device *dev)
{
struct amba_device *pcdev = to_amba_device(dev);
struct amba_driver *drv = to_amba_driver(dev->driver);
- int ret;
pm_runtime_get_sync(dev);
- ret = drv->remove(pcdev);
+ if (drv->remove)
+ drv->remove(pcdev);
pm_runtime_put_noidle(dev);
/* Undo the runtime PM settings in amba_probe() */
@@ -313,15 +237,101 @@ static int amba_remove(struct device *dev)
amba_put_disable_pclk(pcdev);
dev_pm_domain_detach(dev, true);
- return ret;
+ return 0;
}
static void amba_shutdown(struct device *dev)
{
- struct amba_driver *drv = to_amba_driver(dev->driver);
- drv->shutdown(to_amba_device(dev));
+ struct amba_driver *drv;
+
+ if (!dev->driver)
+ return;
+
+ drv = to_amba_driver(dev->driver);
+ if (drv->shutdown)
+ drv->shutdown(to_amba_device(dev));
+}
+
+#ifdef CONFIG_PM
+/*
+ * Hooks to provide runtime PM of the pclk (bus clock). It is safe to
+ * enable/disable the bus clock at runtime PM suspend/resume as this
+ * does not result in loss of context.
+ */
+static int amba_pm_runtime_suspend(struct device *dev)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ int ret = pm_generic_runtime_suspend(dev);
+
+ if (ret == 0 && dev->driver) {
+ if (pm_runtime_is_irq_safe(dev))
+ clk_disable(pcdev->pclk);
+ else
+ clk_disable_unprepare(pcdev->pclk);
+ }
+
+ return ret;
+}
+
+static int amba_pm_runtime_resume(struct device *dev)
+{
+ struct amba_device *pcdev = to_amba_device(dev);
+ int ret;
+
+ if (dev->driver) {
+ if (pm_runtime_is_irq_safe(dev))
+ ret = clk_enable(pcdev->pclk);
+ else
+ ret = clk_prepare_enable(pcdev->pclk);
+ /* Failure is probably fatal to the system, but... */
+ if (ret)
+ return ret;
+ }
+
+ return pm_generic_runtime_resume(dev);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops amba_pm = {
+ .suspend = pm_generic_suspend,
+ .resume = pm_generic_resume,
+ .freeze = pm_generic_freeze,
+ .thaw = pm_generic_thaw,
+ .poweroff = pm_generic_poweroff,
+ .restore = pm_generic_restore,
+ SET_RUNTIME_PM_OPS(
+ amba_pm_runtime_suspend,
+ amba_pm_runtime_resume,
+ NULL
+ )
+};
+
+/*
+ * Primecells are part of the Advanced Microcontroller Bus Architecture,
+ * so we call the bus "amba".
+ * DMA configuration for platform and AMBA bus is same. So here we reuse
+ * platform's DMA config routine.
+ */
+struct bus_type amba_bustype = {
+ .name = "amba",
+ .dev_groups = amba_dev_groups,
+ .match = amba_match,
+ .uevent = amba_uevent,
+ .probe = amba_probe,
+ .remove = amba_remove,
+ .shutdown = amba_shutdown,
+ .dma_configure = platform_dma_configure,
+ .pm = &amba_pm,
+};
+EXPORT_SYMBOL_GPL(amba_bustype);
+
+static int __init amba_init(void)
+{
+ return bus_register(&amba_bustype);
}
+postcore_initcall(amba_init);
+
/**
* amba_driver_register - register an AMBA device driver
* @drv: amba device driver structure
@@ -332,12 +342,10 @@ static void amba_shutdown(struct device *dev)
*/
int amba_driver_register(struct amba_driver *drv)
{
- drv->drv.bus = &amba_bustype;
+ if (!drv->probe)
+ return -EINVAL;
-#define SETFN(fn) if (drv->fn) drv->drv.fn = amba_##fn
- SETFN(probe);
- SETFN(remove);
- SETFN(shutdown);
+ drv->drv.bus = &amba_bustype;
return driver_register(&drv->drv);
}