ARM / Samsung: Use struct syscore_ops for "core" power management

Replace sysdev classes and struct sys_device objects used for "core"
power management by Samsung platforms with struct syscore_ops objects
that are simpler.

This generally reduces the code size and the kernel memory footprint.
It also is necessary for removing sysdevs entirely from the kernel in
the future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>

1 files changed, 26 insertions, 42 deletions

diff --git a/arch/arm/plat-s3c24xx/dma.c b/arch/arm/plat-s3c24xx/dma.c
index 27ea852e3370..c10d10c56e2e 100644
--- a/arch/arm/plat-s3c24xx/dma.c
+++ b/arch/arm/plat-s3c24xx/dma.c
@@ -22,7 +22,7 @@
 #include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
-#include <linux/sysdev.h>
+#include <linux/syscore_ops.h>
 #include <linux/slab.h>
 #include <linux/errno.h>
 #include <linux/io.h>
@@ -1195,19 +1195,12 @@ int s3c2410_dma_getposition(unsigned int channel, dma_addr_t *src, dma_addr_t *d
 
 EXPORT_SYMBOL(s3c2410_dma_getposition);
 
-static inline struct s3c2410_dma_chan *to_dma_chan(struct sys_device *dev)
-{
-        return container_of(dev, struct s3c2410_dma_chan, dev);
-}
-
-/* system device class */
+/* system core operations */
 
 #ifdef CONFIG_PM
 
-static int s3c2410_dma_suspend(struct sys_device *dev, pm_message_t state)
+static void s3c2410_dma_suspend_chan(s3c2410_dma_chan *cp)
 {
-        struct s3c2410_dma_chan *cp = to_dma_chan(dev);
-
         printk(KERN_DEBUG "suspending dma channel %d\n", cp->number);
 
         if (dma_rdreg(cp, S3C2410_DMA_DMASKTRIG) & S3C2410_DMASKTRIG_ON) {
@@ -1222,13 +1215,21 @@ static int s3c2410_dma_suspend(struct sys_device *dev, pm_message_t state)
 
                 s3c2410_dma_dostop(cp);
         }
+}
+
+static int s3c2410_dma_suspend(void)
+{
+        struct s3c2410_dma_chan *cp = s3c2410_chans;
+        int channel;
+
+        for (channel = 0; channel < dma_channels; cp++, channel++)
+                s3c2410_dma_suspend_chan(cp);
 
         return 0;
 }
 
-static int s3c2410_dma_resume(struct sys_device *dev)
+static void s3c2410_dma_resume_chan(struct s3c2410_dma_chan *cp)
 {
-        struct s3c2410_dma_chan *cp = to_dma_chan(dev);
         unsigned int no = cp->number | DMACH_LOW_LEVEL;
 
         /* restore channel's hardware configuration */
@@ -1249,13 +1250,21 @@ static int s3c2410_dma_resume(struct sys_device *dev)
         return 0;
 }
 
+static void s3c2410_dma_resume(void)
+{
+        struct s3c2410_dma_chan *cp = s3c2410_chans + dma_channels - 1;
+        int channel;
+
+        for (channel = dma_channels - 1; channel >= 0; cp++, channel--)
+                s3c2410_dma_resume_chan(cp);
+}
+
 #else
 #define s3c2410_dma_suspend NULL
 #define s3c2410_dma_resume  NULL
 #endif /* CONFIG_PM */
 
-struct sysdev_class dma_sysclass = {
-        .name           = "s3c24xx-dma",
+struct syscore_ops dma_syscore_ops = {
         .suspend        = s3c2410_dma_suspend,
         .resume         = s3c2410_dma_resume,
 };
@@ -1269,39 +1278,14 @@ static void s3c2410_dma_cache_ctor(void *p)
 
 /* initialisation code */
 
-static int __init s3c24xx_dma_sysclass_init(void)
+static int __init s3c24xx_dma_syscore_init(void)
 {
-        int ret = sysdev_class_register(&dma_sysclass);
-
-        if (ret != 0)
-                printk(KERN_ERR "dma sysclass registration failed\n");
-
-        return ret;
-}
-
-core_initcall(s3c24xx_dma_sysclass_init);
-
-static int __init s3c24xx_dma_sysdev_register(void)
-{
-        struct s3c2410_dma_chan *cp = s3c2410_chans;
-        int channel, ret;
-
-        for (channel = 0; channel < dma_channels; cp++, channel++) {
-                cp->dev.cls = &dma_sysclass;
-                cp->dev.id  = channel;
-                ret = sysdev_register(&cp->dev);
-
-                if (ret) {
-                        printk(KERN_ERR "error registering dev for dma %d\n",
-                               channel);
-                        return ret;
-                }
-        }
+        register_syscore_ops(&dma_syscore_ops);
 
         return 0;
 }
 
-late_initcall(s3c24xx_dma_sysdev_register);
+late_initcall(s3c24xx_dma_syscore_init);
 
 int __init s3c24xx_dma_init(unsigned int channels, unsigned int irq,
                             unsigned int stride)